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Copyright (C) 1988-2023 Free Software Foundation, Inc.

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Invariant Sections being "Free Software" and "Free Software Needs Free
Documentation", with the Front-Cover Texts being "A GNU Manual," and
with the Back-Cover Texts as in (a) below.

   (a) The FSF's Back-Cover Text is: "You are free to copy and modify
this GNU Manual.  Buying copies from GNU Press supports the FSF in
developing GNU and promoting software freedom."
INFO-DIR-SECTION Software development
START-INFO-DIR-ENTRY
* Gdb: (gdb).                     The GNU debugger.
* gdbserver: (gdb) Server.        The GNU debugging server.
END-INFO-DIR-ENTRY

   This file documents the GNU debugger GDB.

   This is the Tenth Edition, of 'Debugging with GDB: the GNU
Source-Level Debugger' for GDB (GDB) Version 13.1.90.20230429-git.

   Copyright (C) 1988-2023 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Free Software" and "Free Software Needs Free
Documentation", with the Front-Cover Texts being "A GNU Manual," and
with the Back-Cover Texts as in (a) below.

   (a) The FSF's Back-Cover Text is: "You are free to copy and modify
this GNU Manual.  Buying copies from GNU Press supports the FSF in
developing GNU and promoting software freedom."


File: gdb.info,  Node: GDB/MI Stream Records,  Next: GDB/MI Async Records,  Prev: GDB/MI Result Records,  Up: GDB/MI Output Records

27.5.2 GDB/MI Stream Records
----------------------------

GDB internally maintains a number of output streams: the console, the
target, and the log.  The output intended for each of these streams is
funneled through the GDB/MI interface using "stream records".

   Each stream record begins with a unique "prefix character" which
identifies its stream (*note GDB/MI Output Syntax: GDB/MI Output
Syntax.).  In addition to the prefix, each stream record contains a
'STRING-OUTPUT'.  This is either raw text (with an implicit new line) or
a quoted C string (which does not contain an implicit newline).

'"~" STRING-OUTPUT'
     The console output stream contains text that should be displayed in
     the CLI console window.  It contains the textual responses to CLI
     commands.

'"@" STRING-OUTPUT'
     The target output stream contains any textual output from the
     running target.  This is only present when GDB's event loop is
     truly asynchronous, which is currently only the case for remote
     targets.

'"&" STRING-OUTPUT'
     The log stream contains debugging messages being produced by GDB's
     internals.


File: gdb.info,  Node: GDB/MI Async Records,  Next: GDB/MI Breakpoint Information,  Prev: GDB/MI Stream Records,  Up: GDB/MI Output Records

27.5.3 GDB/MI Async Records
---------------------------

"Async" records are used to notify the GDB/MI client of additional
changes that have occurred.  Those changes can either be a consequence
of GDB/MI commands (e.g., a breakpoint modified) or a result of target
activity (e.g., target stopped).

   The following is the list of possible async records:

'*running,thread-id="THREAD"'
     The target is now running.  The THREAD field can be the global
     thread ID of the thread that is now running, and it can be 'all' if
     all threads are running.  The frontend should assume that no
     interaction with a running thread is possible after this
     notification is produced.  The frontend should not assume that this
     notification is output only once for any command.  GDB may emit
     this notification several times, either for different threads,
     because it cannot resume all threads together, or even for a single
     thread, if the thread must be stepped though some code before
     letting it run freely.

'*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"'
     The target has stopped.  The REASON field can have one of the
     following values:

     'breakpoint-hit'
          A breakpoint was reached.
     'watchpoint-trigger'
          A watchpoint was triggered.
     'read-watchpoint-trigger'
          A read watchpoint was triggered.
     'access-watchpoint-trigger'
          An access watchpoint was triggered.
     'function-finished'
          An -exec-finish or similar CLI command was accomplished.
     'location-reached'
          An -exec-until or similar CLI command was accomplished.
     'watchpoint-scope'
          A watchpoint has gone out of scope.
     'end-stepping-range'
          An -exec-next, -exec-next-instruction, -exec-step,
          -exec-step-instruction or similar CLI command was
          accomplished.
     'exited-signalled'
          The inferior exited because of a signal.
     'exited'
          The inferior exited.
     'exited-normally'
          The inferior exited normally.
     'signal-received'
          A signal was received by the inferior.
     'solib-event'
          The inferior has stopped due to a library being loaded or
          unloaded.  This can happen when 'stop-on-solib-events' (*note
          Files::) is set or when a 'catch load' or 'catch unload'
          catchpoint is in use (*note Set Catchpoints::).
     'fork'
          The inferior has forked.  This is reported when 'catch fork'
          (*note Set Catchpoints::) has been used.
     'vfork'
          The inferior has vforked.  This is reported in when 'catch
          vfork' (*note Set Catchpoints::) has been used.
     'syscall-entry'
          The inferior entered a system call.  This is reported when
          'catch syscall' (*note Set Catchpoints::) has been used.
     'syscall-return'
          The inferior returned from a system call.  This is reported
          when 'catch syscall' (*note Set Catchpoints::) has been used.
     'exec'
          The inferior called 'exec'.  This is reported when 'catch
          exec' (*note Set Catchpoints::) has been used.

     The ID field identifies the global thread ID of the thread that
     directly caused the stop - for example by hitting a breakpoint.
     Depending on whether all-stop mode is in effect (*note All-Stop
     Mode::), GDB may either stop all threads, or only the thread that
     directly triggered the stop.  If all threads are stopped, the
     STOPPED field will have the value of '"all"'.  Otherwise, the value
     of the STOPPED field will be a list of thread identifiers.
     Presently, this list will always include a single thread, but
     frontend should be prepared to see several threads in the list.
     The CORE field reports the processor core on which the stop event
     has happened.  This field may be absent if such information is not
     available.

'=thread-group-added,id="ID"'
'=thread-group-removed,id="ID"'
     A thread group was either added or removed.  The ID field contains
     the GDB identifier of the thread group.  When a thread group is
     added, it generally might not be associated with a running process.
     When a thread group is removed, its id becomes invalid and cannot
     be used in any way.

'=thread-group-started,id="ID",pid="PID"'
     A thread group became associated with a running program, either
     because the program was just started or the thread group was
     attached to a program.  The ID field contains the GDB identifier of
     the thread group.  The PID field contains process identifier,
     specific to the operating system.

'=thread-group-exited,id="ID"[,exit-code="CODE"]'
     A thread group is no longer associated with a running program,
     either because the program has exited, or because it was detached
     from.  The ID field contains the GDB identifier of the thread
     group.  The CODE field is the exit code of the inferior; it exists
     only when the inferior exited with some code.

'=thread-created,id="ID",group-id="GID"'
'=thread-exited,id="ID",group-id="GID"'
     A thread either was created, or has exited.  The ID field contains
     the global GDB identifier of the thread.  The GID field identifies
     the thread group this thread belongs to.

'=thread-selected,id="ID"[,frame="FRAME"]'
     Informs that the selected thread or frame were changed.  This
     notification is not emitted as result of the '-thread-select' or
     '-stack-select-frame' commands, but is emitted whenever an MI
     command that is not documented to change the selected thread and
     frame actually changes them.  In particular, invoking, directly or
     indirectly (via user-defined command), the CLI 'thread' or 'frame'
     commands, will generate this notification.  Changing the thread or
     frame from another user interface (see *note Interpreters::) will
     also generate this notification.

     The FRAME field is only present if the newly selected thread is
     stopped.  See *note GDB/MI Frame Information:: for the format of
     its value.

     We suggest that in response to this notification, front ends
     highlight the selected thread and cause subsequent commands to
     apply to that thread.

'=library-loaded,...'
     Reports that a new library file was loaded by the program.  This
     notification has 5 fields--ID, TARGET-NAME, HOST-NAME,
     SYMBOLS-LOADED and RANGES.  The ID field is an opaque identifier of
     the library.  For remote debugging case, TARGET-NAME and HOST-NAME
     fields give the name of the library file on the target, and on the
     host respectively.  For native debugging, both those fields have
     the same value.  The SYMBOLS-LOADED field is emitted only for
     backward compatibility and should not be relied on to convey any
     useful information.  The THREAD-GROUP field, if present, specifies
     the id of the thread group in whose context the library was loaded.
     If the field is absent, it means the library was loaded in the
     context of all present thread groups.  The RANGES field specifies
     the ranges of addresses belonging to this library.

'=library-unloaded,...'
     Reports that a library was unloaded by the program.  This
     notification has 3 fields--ID, TARGET-NAME and HOST-NAME with the
     same meaning as for the '=library-loaded' notification.  The
     THREAD-GROUP field, if present, specifies the id of the thread
     group in whose context the library was unloaded.  If the field is
     absent, it means the library was unloaded in the context of all
     present thread groups.

'=traceframe-changed,num=TFNUM,tracepoint=TPNUM'
'=traceframe-changed,end'
     Reports that the trace frame was changed and its new number is
     TFNUM.  The number of the tracepoint associated with this trace
     frame is TPNUM.

'=tsv-created,name=NAME,initial=INITIAL'
     Reports that the new trace state variable NAME is created with
     initial value INITIAL.

'=tsv-deleted,name=NAME'
'=tsv-deleted'
     Reports that the trace state variable NAME is deleted or all trace
     state variables are deleted.

'=tsv-modified,name=NAME,initial=INITIAL[,current=CURRENT]'
     Reports that the trace state variable NAME is modified with the
     initial value INITIAL.  The current value CURRENT of trace state
     variable is optional and is reported if the current value of trace
     state variable is known.

'=breakpoint-created,bkpt={...}'
'=breakpoint-modified,bkpt={...}'
'=breakpoint-deleted,id=NUMBER'
     Reports that a breakpoint was created, modified, or deleted,
     respectively.  Only user-visible breakpoints are reported to the MI
     user.

     The BKPT argument is of the same form as returned by the various
     breakpoint commands; *Note GDB/MI Breakpoint Commands::.  The
     NUMBER is the ordinal number of the breakpoint.

     Note that if a breakpoint is emitted in the result record of a
     command, then it will not also be emitted in an async record.

'=record-started,thread-group="ID",method="METHOD"[,format="FORMAT"]'
'=record-stopped,thread-group="ID"'
     Execution log recording was either started or stopped on an
     inferior.  The ID is the GDB identifier of the thread group
     corresponding to the affected inferior.

     The METHOD field indicates the method used to record execution.  If
     the method in use supports multiple recording formats, FORMAT will
     be present and contain the currently used format.  *Note Process
     Record and Replay::, for existing method and format values.

'=cmd-param-changed,param=PARAM,value=VALUE'
     Reports that a parameter of the command 'set PARAM' is changed to
     VALUE.  In the multi-word 'set' command, the PARAM is the whole
     parameter list to 'set' command.  For example, In command 'set
     check type on', PARAM is 'check type' and VALUE is 'on'.

'=memory-changed,thread-group=ID,addr=ADDR,len=LEN[,type="code"]'
     Reports that bytes from ADDR to DATA + LEN were written in an
     inferior.  The ID is the identifier of the thread group
     corresponding to the affected inferior.  The optional 'type="code"'
     part is reported if the memory written to holds executable code.


File: gdb.info,  Node: GDB/MI Breakpoint Information,  Next: GDB/MI Frame Information,  Prev: GDB/MI Async Records,  Up: GDB/MI Output Records

27.5.4 GDB/MI Breakpoint Information
------------------------------------

When GDB reports information about a breakpoint, a tracepoint, a
watchpoint, or a catchpoint, it uses a tuple with the following fields:

'number'
     The breakpoint number.

'type'
     The type of the breakpoint.  For ordinary breakpoints this will be
     'breakpoint', but many values are possible.

'catch-type'
     If the type of the breakpoint is 'catchpoint', then this indicates
     the exact type of catchpoint.

'disp'
     This is the breakpoint disposition--either 'del', meaning that the
     breakpoint will be deleted at the next stop, or 'keep', meaning
     that the breakpoint will not be deleted.

'enabled'
     This indicates whether the breakpoint is enabled, in which case the
     value is 'y', or disabled, in which case the value is 'n'.  Note
     that this is not the same as the field 'enable'.

'addr'
     The address of the breakpoint.  This may be a hexidecimal number,
     giving the address; or the string '<PENDING>', for a pending
     breakpoint; or the string '<MULTIPLE>', for a breakpoint with
     multiple locations.  This field will not be present if no address
     can be determined.  For example, a watchpoint does not have an
     address.

'addr_flags'
     Optional field containing any flags related to the address.  These
     flags are architecture-dependent; see *note Architectures:: for
     their meaning for a particular CPU.

'func'
     If known, the function in which the breakpoint appears.  If not
     known, this field is not present.

'filename'
     The name of the source file which contains this function, if known.
     If not known, this field is not present.

'fullname'
     The full file name of the source file which contains this function,
     if known.  If not known, this field is not present.

'line'
     The line number at which this breakpoint appears, if known.  If not
     known, this field is not present.

'at'
     If the source file is not known, this field may be provided.  If
     provided, this holds the address of the breakpoint, possibly
     followed by a symbol name.

'pending'
     If this breakpoint is pending, this field is present and holds the
     text used to set the breakpoint, as entered by the user.

'evaluated-by'
     Where this breakpoint's condition is evaluated, either 'host' or
     'target'.

'thread'
     If this is a thread-specific breakpoint, then this identifies the
     thread in which the breakpoint can trigger.

'task'
     If this breakpoint is restricted to a particular Ada task, then
     this field will hold the task identifier.

'cond'
     If the breakpoint is conditional, this is the condition expression.

'ignore'
     The ignore count of the breakpoint.

'enable'
     The enable count of the breakpoint.

'traceframe-usage'
     FIXME.

'static-tracepoint-marker-string-id'
     For a static tracepoint, the name of the static tracepoint marker.

'mask'
     For a masked watchpoint, this is the mask.

'pass'
     A tracepoint's pass count.

'original-location'
     The location of the breakpoint as originally specified by the user.
     This field is optional.

'times'
     The number of times the breakpoint has been hit.

'installed'
     This field is only given for tracepoints.  This is either 'y',
     meaning that the tracepoint is installed, or 'n', meaning that it
     is not.

'what'
     Some extra data, the exact contents of which are type-dependent.

'locations'
     This field is present if the breakpoint has multiple locations.  It
     is also exceptionally present if the breakpoint is enabled and has
     a single, disabled location.

     The value is a list of locations.  The format of a location is
     described below.

   A location in a multi-location breakpoint is represented as a tuple
with the following fields:

'number'
     The location number as a dotted pair, like '1.2'.  The first digit
     is the number of the parent breakpoint.  The second digit is the
     number of the location within that breakpoint.

'enabled'
     There are three possible values, with the following meanings:
     'y'
          The location is enabled.
     'n'
          The location is disabled by the user.
     'N'
          The location is disabled because the breakpoint condition is
          invalid at this location.

'addr'
     The address of this location as an hexidecimal number.

'addr_flags'
     Optional field containing any flags related to the address.  These
     flags are architecture-dependent; see *note Architectures:: for
     their meaning for a particular CPU.

'func'
     If known, the function in which the location appears.  If not
     known, this field is not present.

'file'
     The name of the source file which contains this location, if known.
     If not known, this field is not present.

'fullname'
     The full file name of the source file which contains this location,
     if known.  If not known, this field is not present.

'line'
     The line number at which this location appears, if known.  If not
     known, this field is not present.

'thread-groups'
     The thread groups this location is in.

   For example, here is what the output of '-break-insert' (*note GDB/MI
Breakpoint Commands::) might be:

     -> -break-insert main
     <- ^done,bkpt={number="1",type="breakpoint",disp="keep",
         enabled="y",addr="0x08048564",func="main",file="myprog.c",
         fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"],
         times="0"}
     <- (gdb)


File: gdb.info,  Node: GDB/MI Frame Information,  Next: GDB/MI Thread Information,  Prev: GDB/MI Breakpoint Information,  Up: GDB/MI Output Records

27.5.5 GDB/MI Frame Information
-------------------------------

Response from many MI commands includes an information about stack
frame.  This information is a tuple that may have the following fields:

'level'
     The level of the stack frame.  The innermost frame has the level of
     zero.  This field is always present.

'func'
     The name of the function corresponding to the frame.  This field
     may be absent if GDB is unable to determine the function name.

'addr'
     The code address for the frame.  This field is always present.

'addr_flags'
     Optional field containing any flags related to the address.  These
     flags are architecture-dependent; see *note Architectures:: for
     their meaning for a particular CPU.

'file'
     The name of the source files that correspond to the frame's code
     address.  This field may be absent.

'line'
     The source line corresponding to the frames' code address.  This
     field may be absent.

'from'
     The name of the binary file (either executable or shared library)
     the corresponds to the frame's code address.  This field may be
     absent.


File: gdb.info,  Node: GDB/MI Thread Information,  Next: GDB/MI Ada Exception Information,  Prev: GDB/MI Frame Information,  Up: GDB/MI Output Records

27.5.6 GDB/MI Thread Information
--------------------------------

Whenever GDB has to report an information about a thread, it uses a
tuple with the following fields.  The fields are always present unless
stated otherwise.

'id'
     The global numeric id assigned to the thread by GDB.

'target-id'
     The target-specific string identifying the thread.

'details'
     Additional information about the thread provided by the target.  It
     is supposed to be human-readable and not interpreted by the
     frontend.  This field is optional.

'name'
     The name of the thread.  If the user specified a name using the
     'thread name' command, then this name is given.  Otherwise, if GDB
     can extract the thread name from the target, then that name is
     given.  If GDB cannot find the thread name, then this field is
     omitted.

'state'
     The execution state of the thread, either 'stopped' or 'running',
     depending on whether the thread is presently running.

'frame'
     The stack frame currently executing in the thread.  This field is
     only present if the thread is stopped.  Its format is documented in
     *note GDB/MI Frame Information::.

'core'
     The value of this field is an integer number of the processor core
     the thread was last seen on.  This field is optional.


File: gdb.info,  Node: GDB/MI Ada Exception Information,  Prev: GDB/MI Thread Information,  Up: GDB/MI Output Records

27.5.7 GDB/MI Ada Exception Information
---------------------------------------

Whenever a '*stopped' record is emitted because the program stopped
after hitting an exception catchpoint (*note Set Catchpoints::), GDB
provides the name of the exception that was raised via the
'exception-name' field.  Also, for exceptions that were raised with an
exception message, GDB provides that message via the 'exception-message'
field.


File: gdb.info,  Node: GDB/MI Simple Examples,  Next: GDB/MI Command Description Format,  Prev: GDB/MI Output Records,  Up: GDB/MI

27.6 Simple Examples of GDB/MI Interaction
==========================================

This subsection presents several simple examples of interaction using
the GDB/MI interface.  In these examples, '->' means that the following
line is passed to GDB/MI as input, while '<-' means the output received
from GDB/MI.

   Note the line breaks shown in the examples are here only for
readability, they don't appear in the real output.

Setting a Breakpoint
--------------------

Setting a breakpoint generates synchronous output which contains
detailed information of the breakpoint.

     -> -break-insert main
     <- ^done,bkpt={number="1",type="breakpoint",disp="keep",
         enabled="y",addr="0x08048564",func="main",file="myprog.c",
         fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"],
         times="0"}
     <- (gdb)

Program Execution
-----------------

Program execution generates asynchronous records and MI gives the reason
that execution stopped.

     -> -exec-run
     <- ^running
     <- (gdb)
     <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
        frame={addr="0x08048564",func="main",
        args=[{name="argc",value="1"},{name="argv",value="0xbfc4d4d4"}],
        file="myprog.c",fullname="/home/nickrob/myprog.c",line="68",
        arch="i386:x86_64"}
     <- (gdb)
     -> -exec-continue
     <- ^running
     <- (gdb)
     <- *stopped,reason="exited-normally"
     <- (gdb)

Quitting GDB
------------

Quitting GDB just prints the result class '^exit'.

     -> (gdb)
     <- -gdb-exit
     <- ^exit

   Please note that '^exit' is printed immediately, but it might take
some time for GDB to actually exit.  During that time, GDB performs
necessary cleanups, including killing programs being debugged or
disconnecting from debug hardware, so the frontend should wait till GDB
exits and should only forcibly kill GDB if it fails to exit in
reasonable time.

A Bad Command
-------------

Here's what happens if you pass a non-existent command:

     -> -rubbish
     <- ^error,msg="Undefined MI command: rubbish"
     <- (gdb)


File: gdb.info,  Node: GDB/MI Command Description Format,  Next: GDB/MI Breakpoint Commands,  Prev: GDB/MI Simple Examples,  Up: GDB/MI

27.7 GDB/MI Command Description Format
======================================

The remaining sections describe blocks of commands.  Each block of
commands is laid out in a fashion similar to this section.

Motivation
----------

The motivation for this collection of commands.

Introduction
------------

A brief introduction to this collection of commands as a whole.

Commands
--------

For each command in the block, the following is described:

Synopsis
........

      -command ARGS...

Result
......

GDB Command
...........

The corresponding GDB CLI command(s), if any.

Example
.......

Example(s) formatted for readability.  Some of the described commands
have not been implemented yet and these are labeled N.A. (not
available).


File: gdb.info,  Node: GDB/MI Breakpoint Commands,  Next: GDB/MI Catchpoint Commands,  Prev: GDB/MI Command Description Format,  Up: GDB/MI

27.8 GDB/MI Breakpoint Commands
===============================

This section documents GDB/MI commands for manipulating breakpoints.

The '-break-after' Command
--------------------------

Synopsis
........

      -break-after NUMBER COUNT

   The breakpoint number NUMBER is not in effect until it has been hit
COUNT times.  To see how this is reflected in the output of the
'-break-list' command, see the description of the '-break-list' command
below.

GDB Command
...........

The corresponding GDB command is 'ignore'.

Example
.......

     (gdb)
     -break-insert main
     ^done,bkpt={number="1",type="breakpoint",disp="keep",
     enabled="y",addr="0x000100d0",func="main",file="hello.c",
     fullname="/home/foo/hello.c",line="5",thread-groups=["i1"],
     times="0"}
     (gdb)
     -break-after 1 3
     ~
     ^done
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="1",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
     line="5",thread-groups=["i1"],times="0",ignore="3"}]}
     (gdb)

The '-break-commands' Command
-----------------------------

Synopsis
........

      -break-commands NUMBER [ COMMAND1 ... COMMANDN ]

   Specifies the CLI commands that should be executed when breakpoint
NUMBER is hit.  The parameters COMMAND1 to COMMANDN are the commands.
If no command is specified, any previously-set commands are cleared.
*Note Break Commands::.  Typical use of this functionality is tracing a
program, that is, printing of values of some variables whenever
breakpoint is hit and then continuing.

GDB Command
...........

The corresponding GDB command is 'commands'.

Example
.......

     (gdb)
     -break-insert main
     ^done,bkpt={number="1",type="breakpoint",disp="keep",
     enabled="y",addr="0x000100d0",func="main",file="hello.c",
     fullname="/home/foo/hello.c",line="5",thread-groups=["i1"],
     times="0"}
     (gdb)
     -break-commands 1 "print v" "continue"
     ^done
     (gdb)

The '-break-condition' Command
------------------------------

Synopsis
........

      -break-condition [ --force ] NUMBER [ EXPR ]

   Breakpoint NUMBER will stop the program only if the condition in EXPR
is true.  The condition becomes part of the '-break-list' output (see
the description of the '-break-list' command below).  If the '--force'
flag is passed, the condition is forcibly defined even when it is
invalid for all locations of breakpoint NUMBER.  If the EXPR argument is
omitted, breakpoint NUMBER becomes unconditional.

GDB Command
...........

The corresponding GDB command is 'condition'.

Example
.......

     (gdb)
     -break-condition 1 1
     ^done
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="1",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
     line="5",cond="1",thread-groups=["i1"],times="0",ignore="3"}]}
     (gdb)

The '-break-delete' Command
---------------------------

Synopsis
........

      -break-delete ( BREAKPOINT )+

   Delete the breakpoint(s) whose number(s) are specified in the
argument list.  This is obviously reflected in the breakpoint list.

GDB Command
...........

The corresponding GDB command is 'delete'.

Example
.......

     (gdb)
     -break-delete 1
     ^done
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="0",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[]}
     (gdb)

The '-break-disable' Command
----------------------------

Synopsis
........

      -break-disable ( BREAKPOINT )+

   Disable the named BREAKPOINT(s).  The field 'enabled' in the break
list is now set to 'n' for the named BREAKPOINT(s).

GDB Command
...........

The corresponding GDB command is 'disable'.

Example
.......

     (gdb)
     -break-disable 2
     ^done
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="1",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="n",
     addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
     line="5",thread-groups=["i1"],times="0"}]}
     (gdb)

The '-break-enable' Command
---------------------------

Synopsis
........

      -break-enable ( BREAKPOINT )+

   Enable (previously disabled) BREAKPOINT(s).

GDB Command
...........

The corresponding GDB command is 'enable'.

Example
.......

     (gdb)
     -break-enable 2
     ^done
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="1",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
     addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
     line="5",thread-groups=["i1"],times="0"}]}
     (gdb)

The '-break-info' Command
-------------------------

Synopsis
........

      -break-info BREAKPOINT

   Get information about a single breakpoint.

   The result is a table of breakpoints.  *Note GDB/MI Breakpoint
Information::, for details on the format of each breakpoint in the
table.

GDB Command
...........

The corresponding GDB command is 'info break BREAKPOINT'.

Example
.......

N.A.

The '-break-insert' Command
---------------------------

Synopsis
........

      -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ] [ --qualified ]
         [ -c CONDITION ] [ --force-condition ] [ -i IGNORE-COUNT ]
         [ -p THREAD-ID ] [ LOCSPEC ]

If specified, LOCSPEC, can be one of:

LINESPEC LOCATION
     A linespec location.  *Note Linespec Locations::.

EXPLICIT LOCATION
     An explicit location.  GDB/MI explicit locations are analogous to
     the CLI's explicit locations using the option names listed below.
     *Note Explicit Locations::.

     '--source FILENAME'
          The source file name of the location.  This option requires
          the use of either '--function' or '--line'.

     '--function FUNCTION'
          The name of a function or method.

     '--label LABEL'
          The name of a label.

     '--line LINEOFFSET'
          An absolute or relative line offset from the start of the
          location.

ADDRESS LOCATION
     An address location, *ADDRESS.  *Note Address Locations::.

The possible optional parameters of this command are:

'-t'
     Insert a temporary breakpoint.
'-h'
     Insert a hardware breakpoint.
'-f'
     If LOCSPEC cannot be resolved (for example if it refers to unknown
     files or functions), create a pending breakpoint.  Without this
     flag, GDB will report an error, and won't create a breakpoint, if
     LOCSPEC cannot be parsed.
'-d'
     Create a disabled breakpoint.
'-a'
     Create a tracepoint.  *Note Tracepoints::.  When this parameter is
     used together with '-h', a fast tracepoint is created.
'-c CONDITION'
     Make the breakpoint conditional on CONDITION.
'--force-condition'
     Forcibly define the breakpoint even if the condition is invalid at
     all of the breakpoint locations.
'-i IGNORE-COUNT'
     Initialize the IGNORE-COUNT.
'-p THREAD-ID'
     Restrict the breakpoint to the thread with the specified global
     THREAD-ID.
'--qualified'
     This option makes GDB interpret a function name specified as a
     complete fully-qualified name.

Result
......

*Note GDB/MI Breakpoint Information::, for details on the format of the
resulting breakpoint.

   Note: this format is open to change.

GDB Command
...........

The corresponding GDB commands are 'break', 'tbreak', 'hbreak', and
'thbreak'.

Example
.......

     (gdb)
     -break-insert main
     ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",
     fullname="/home/foo/recursive2.c,line="4",thread-groups=["i1"],
     times="0"}
     (gdb)
     -break-insert -t foo
     ^done,bkpt={number="2",addr="0x00010774",file="recursive2.c",
     fullname="/home/foo/recursive2.c,line="11",thread-groups=["i1"],
     times="0"}
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="2",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x0001072c", func="main",file="recursive2.c",
     fullname="/home/foo/recursive2.c,"line="4",thread-groups=["i1"],
     times="0"},
     bkpt={number="2",type="breakpoint",disp="del",enabled="y",
     addr="0x00010774",func="foo",file="recursive2.c",
     fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"],
     times="0"}]}
     (gdb)

The '-dprintf-insert' Command
-----------------------------

Synopsis
........

      -dprintf-insert [ -t ] [ -f ] [ -d ] [ --qualified ]
         [ -c CONDITION ] [--force-condition] [ -i IGNORE-COUNT ]
         [ -p THREAD-ID ] [ LOCSPEC ] [ FORMAT ]
         [ ARGUMENT ]

If supplied, LOCSPEC and '--qualified' may be specified the same way as
for the '-break-insert' command.  *Note -break-insert::.

   The possible optional parameters of this command are:

'-t'
     Insert a temporary breakpoint.
'-f'
     If LOCSPEC cannot be parsed (for example, if it refers to unknown
     files or functions), create a pending breakpoint.  Without this
     flag, GDB will report an error, and won't create a breakpoint, if
     LOCSPEC cannot be parsed.
'-d'
     Create a disabled breakpoint.
'-c CONDITION'
     Make the breakpoint conditional on CONDITION.
'--force-condition'
     Forcibly define the breakpoint even if the condition is invalid at
     all of the breakpoint locations.
'-i IGNORE-COUNT'
     Set the ignore count of the breakpoint (*note ignore count:
     Conditions.) to IGNORE-COUNT.
'-p THREAD-ID'
     Restrict the breakpoint to the thread with the specified global
     THREAD-ID.

Result
......

*Note GDB/MI Breakpoint Information::, for details on the format of the
resulting breakpoint.

GDB Command
...........

The corresponding GDB command is 'dprintf'.

Example
.......

     (gdb)
     4-dprintf-insert foo "At foo entry\n"
     4^done,bkpt={number="1",type="dprintf",disp="keep",enabled="y",
     addr="0x000000000040061b",func="foo",file="mi-dprintf.c",
     fullname="mi-dprintf.c",line="25",thread-groups=["i1"],
     times="0",script=["printf \"At foo entry\\n\"","continue"],
     original-location="foo"}
     (gdb)
     5-dprintf-insert 26 "arg=%d, g=%d\n" arg g
     5^done,bkpt={number="2",type="dprintf",disp="keep",enabled="y",
     addr="0x000000000040062a",func="foo",file="mi-dprintf.c",
     fullname="mi-dprintf.c",line="26",thread-groups=["i1"],
     times="0",script=["printf \"arg=%d, g=%d\\n\", arg, g","continue"],
     original-location="mi-dprintf.c:26"}
     (gdb)

The '-break-list' Command
-------------------------

Synopsis
........

      -break-list

   Displays the list of inserted breakpoints, showing the following
fields:

'Number'
     number of the breakpoint
'Type'
     type of the breakpoint: 'breakpoint' or 'watchpoint'
'Disposition'
     should the breakpoint be deleted or disabled when it is hit: 'keep'
     or 'nokeep'
'Enabled'
     is the breakpoint enabled or no: 'y' or 'n'
'Address'
     memory location at which the breakpoint is set
'What'
     logical location of the breakpoint, expressed by function name,
     file name, line number
'Thread-groups'
     list of thread groups to which this breakpoint applies
'Times'
     number of times the breakpoint has been hit

   If there are no breakpoints or watchpoints, the 'BreakpointTable'
'body' field is an empty list.

GDB Command
...........

The corresponding GDB command is 'info break'.

Example
.......

     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="2",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x000100d0",func="main",file="hello.c",line="5",thread-groups=["i1"],
     times="0"},
     bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
     addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c",
     line="13",thread-groups=["i1"],times="0"}]}
     (gdb)

   Here's an example of the result when there are no breakpoints:

     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="0",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[]}
     (gdb)

The '-break-passcount' Command
------------------------------

Synopsis
........

      -break-passcount TRACEPOINT-NUMBER PASSCOUNT

   Set the passcount for tracepoint TRACEPOINT-NUMBER to PASSCOUNT.  If
the breakpoint referred to by TRACEPOINT-NUMBER is not a tracepoint,
error is emitted.  This corresponds to CLI command 'passcount'.

The '-break-watch' Command
--------------------------

Synopsis
........

      -break-watch [ -a | -r ]

   Create a watchpoint.  With the '-a' option it will create an "access"
watchpoint, i.e., a watchpoint that triggers either on a read from or on
a write to the memory location.  With the '-r' option, the watchpoint
created is a "read" watchpoint, i.e., it will trigger only when the
memory location is accessed for reading.  Without either of the options,
the watchpoint created is a regular watchpoint, i.e., it will trigger
when the memory location is accessed for writing.  *Note Setting
Watchpoints: Set Watchpoints.

   Note that '-break-list' will report a single list of watchpoints and
breakpoints inserted.

GDB Command
...........

The corresponding GDB commands are 'watch', 'awatch', and 'rwatch'.

Example
.......

Setting a watchpoint on a variable in the 'main' function:

     (gdb)
     -break-watch x
     ^done,wpt={number="2",exp="x"}
     (gdb)
     -exec-continue
     ^running
     (gdb)
     *stopped,reason="watchpoint-trigger",wpt={number="2",exp="x"},
     value={old="-268439212",new="55"},
     frame={func="main",args=[],file="recursive2.c",
     fullname="/home/foo/bar/recursive2.c",line="5",arch="i386:x86_64"}
     (gdb)

   Setting a watchpoint on a variable local to a function.  GDB will
stop the program execution twice: first for the variable changing value,
then for the watchpoint going out of scope.

     (gdb)
     -break-watch C
     ^done,wpt={number="5",exp="C"}
     (gdb)
     -exec-continue
     ^running
     (gdb)
     *stopped,reason="watchpoint-trigger",
     wpt={number="5",exp="C"},value={old="-276895068",new="3"},
     frame={func="callee4",args=[],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13",
     arch="i386:x86_64"}
     (gdb)
     -exec-continue
     ^running
     (gdb)
     *stopped,reason="watchpoint-scope",wpnum="5",
     frame={func="callee3",args=[{name="strarg",
     value="0x11940 \"A string argument.\""}],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18",
     arch="i386:x86_64"}
     (gdb)

   Listing breakpoints and watchpoints, at different points in the
program execution.  Note that once the watchpoint goes out of scope, it
is deleted.

     (gdb)
     -break-watch C
     ^done,wpt={number="2",exp="C"}
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="2",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x00010734",func="callee4",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",thread-groups=["i1"],
     times="1"},
     bkpt={number="2",type="watchpoint",disp="keep",
     enabled="y",addr="",what="C",thread-groups=["i1"],times="0"}]}
     (gdb)
     -exec-continue
     ^running
     (gdb)
     *stopped,reason="watchpoint-trigger",wpt={number="2",exp="C"},
     value={old="-276895068",new="3"},
     frame={func="callee4",args=[],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13",
     arch="i386:x86_64"}
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="2",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x00010734",func="callee4",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",thread-groups=["i1"],
     times="1"},
     bkpt={number="2",type="watchpoint",disp="keep",
     enabled="y",addr="",what="C",thread-groups=["i1"],times="-5"}]}
     (gdb)
     -exec-continue
     ^running
     ^done,reason="watchpoint-scope",wpnum="2",
     frame={func="callee3",args=[{name="strarg",
     value="0x11940 \"A string argument.\""}],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18",
     arch="i386:x86_64"}
     (gdb)
     -break-list
     ^done,BreakpointTable={nr_rows="1",nr_cols="6",
     hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
     {width="14",alignment="-1",col_name="type",colhdr="Type"},
     {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
     {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
     {width="10",alignment="-1",col_name="addr",colhdr="Address"},
     {width="40",alignment="2",col_name="what",colhdr="What"}],
     body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x00010734",func="callee4",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
     thread-groups=["i1"],times="1"}]}
     (gdb)


File: gdb.info,  Node: GDB/MI Catchpoint Commands,  Next: GDB/MI Program Context,  Prev: GDB/MI Breakpoint Commands,  Up: GDB/MI

27.9 GDB/MI Catchpoint Commands
===============================

This section documents GDB/MI commands for manipulating catchpoints.

* Menu:

* Shared Library GDB/MI Catchpoint Commands::
* Ada Exception GDB/MI Catchpoint Commands::
* C++ Exception GDB/MI Catchpoint Commands::


File: gdb.info,  Node: Shared Library GDB/MI Catchpoint Commands,  Next: Ada Exception GDB/MI Catchpoint Commands,  Up: GDB/MI Catchpoint Commands

27.9.1 Shared Library GDB/MI Catchpoints
----------------------------------------

The '-catch-load' Command
-------------------------

Synopsis
........

      -catch-load [ -t ] [ -d ] REGEXP

   Add a catchpoint for library load events.  If the '-t' option is
used, the catchpoint is a temporary one (*note Setting Breakpoints: Set
Breaks.).  If the '-d' option is used, the catchpoint is created in a
disabled state.  The 'regexp' argument is a regular expression used to
match the name of the loaded library.

GDB Command
...........

The corresponding GDB command is 'catch load'.

Example
.......

     -catch-load -t foo.so
     ^done,bkpt={number="1",type="catchpoint",disp="del",enabled="y",
     what="load of library matching foo.so",catch-type="load",times="0"}
     (gdb)

The '-catch-unload' Command
---------------------------

Synopsis
........

      -catch-unload [ -t ] [ -d ] REGEXP

   Add a catchpoint for library unload events.  If the '-t' option is
used, the catchpoint is a temporary one (*note Setting Breakpoints: Set
Breaks.).  If the '-d' option is used, the catchpoint is created in a
disabled state.  The 'regexp' argument is a regular expression used to
match the name of the unloaded library.

GDB Command
...........

The corresponding GDB command is 'catch unload'.

Example
.......

     -catch-unload -d bar.so
     ^done,bkpt={number="2",type="catchpoint",disp="keep",enabled="n",
     what="load of library matching bar.so",catch-type="unload",times="0"}
     (gdb)


File: gdb.info,  Node: Ada Exception GDB/MI Catchpoint Commands,  Next: C++ Exception GDB/MI Catchpoint Commands,  Prev: Shared Library GDB/MI Catchpoint Commands,  Up: GDB/MI Catchpoint Commands

27.9.2 Ada Exception GDB/MI Catchpoints
---------------------------------------

The following GDB/MI commands can be used to create catchpoints that
stop the execution when Ada exceptions are being raised.

The '-catch-assert' Command
---------------------------

Synopsis
........

      -catch-assert [ -c CONDITION] [ -d ] [ -t ]

   Add a catchpoint for failed Ada assertions.

   The possible optional parameters for this command are:

'-c CONDITION'
     Make the catchpoint conditional on CONDITION.
'-d'
     Create a disabled catchpoint.
'-t'
     Create a temporary catchpoint.

GDB Command
...........

The corresponding GDB command is 'catch assert'.

Example
.......

     -catch-assert
     ^done,bkptno="5",bkpt={number="5",type="breakpoint",disp="keep",
     enabled="y",addr="0x0000000000404888",what="failed Ada assertions",
     thread-groups=["i1"],times="0",
     original-location="__gnat_debug_raise_assert_failure"}
     (gdb)

The '-catch-exception' Command
------------------------------

Synopsis
........

      -catch-exception [ -c CONDITION] [ -d ] [ -e EXCEPTION-NAME ]
         [ -t ] [ -u ]

   Add a catchpoint stopping when Ada exceptions are raised.  By
default, the command stops the program when any Ada exception gets
raised.  But it is also possible, by using some of the optional
parameters described below, to create more selective catchpoints.

   The possible optional parameters for this command are:

'-c CONDITION'
     Make the catchpoint conditional on CONDITION.
'-d'
     Create a disabled catchpoint.
'-e EXCEPTION-NAME'
     Only stop when EXCEPTION-NAME is raised.  This option cannot be
     used combined with '-u'.
'-t'
     Create a temporary catchpoint.
'-u'
     Stop only when an unhandled exception gets raised.  This option
     cannot be used combined with '-e'.

GDB Command
...........

The corresponding GDB commands are 'catch exception' and 'catch
exception unhandled'.

Example
.......

     -catch-exception -e Program_Error
     ^done,bkptno="4",bkpt={number="4",type="breakpoint",disp="keep",
     enabled="y",addr="0x0000000000404874",
     what="`Program_Error' Ada exception", thread-groups=["i1"],
     times="0",original-location="__gnat_debug_raise_exception"}
     (gdb)

The '-catch-handlers' Command
-----------------------------

Synopsis
........

      -catch-handlers [ -c CONDITION] [ -d ] [ -e EXCEPTION-NAME ]
         [ -t ]

   Add a catchpoint stopping when Ada exceptions are handled.  By
default, the command stops the program when any Ada exception gets
handled.  But it is also possible, by using some of the optional
parameters described below, to create more selective catchpoints.

   The possible optional parameters for this command are:

'-c CONDITION'
     Make the catchpoint conditional on CONDITION.
'-d'
     Create a disabled catchpoint.
'-e EXCEPTION-NAME'
     Only stop when EXCEPTION-NAME is handled.
'-t'
     Create a temporary catchpoint.

GDB Command
...........

The corresponding GDB command is 'catch handlers'.

Example
.......

     -catch-handlers -e Constraint_Error
     ^done,bkptno="4",bkpt={number="4",type="breakpoint",disp="keep",
     enabled="y",addr="0x0000000000402f68",
     what="`Constraint_Error' Ada exception handlers",thread-groups=["i1"],
     times="0",original-location="__gnat_begin_handler"}
     (gdb)


File: gdb.info,  Node: C++ Exception GDB/MI Catchpoint Commands,  Prev: Ada Exception GDB/MI Catchpoint Commands,  Up: GDB/MI Catchpoint Commands

27.9.3 C++ Exception GDB/MI Catchpoints
---------------------------------------

The following GDB/MI commands can be used to create catchpoints that
stop the execution when C++ exceptions are being throw, rethrown, or
caught.

The '-catch-throw' Command
--------------------------

Synopsis
........

      -catch-throw [ -t ] [ -r REGEXP]

   Stop when the debuggee throws a C++ exception.  If REGEXP is given,
then only exceptions whose type matches the regular expression will be
caught.

   If '-t' is given, then the catchpoint is enabled only for one stop,
the catchpoint is automatically deleted after stopping once for the
event.

GDB Command
...........

The corresponding GDB commands are 'catch throw' and 'tcatch throw'
(*note Set Catchpoints::).

Example
.......

     -catch-throw -r exception_type
     ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y",
       what="exception throw",catch-type="throw",
       thread-groups=["i1"],
       regexp="exception_type",times="0"}
     (gdb)
     -exec-run
     ^running
     (gdb)
     ~"\n"
     ~"Catchpoint 1 (exception thrown), 0x00007ffff7ae00ed
       in __cxa_throw () from /lib64/libstdc++.so.6\n"
     *stopped,bkptno="1",reason="breakpoint-hit",disp="keep",
       frame={addr="0x00007ffff7ae00ed",func="__cxa_throw",
       args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"},
       thread-id="1",stopped-threads="all",core="6"
     (gdb)

The '-catch-rethrow' Command
----------------------------

Synopsis
........

      -catch-rethrow [ -t ] [ -r REGEXP]

   Stop when a C++ exception is re-thrown.  If REGEXP is given, then
only exceptions whose type matches the regular expression will be
caught.

   If '-t' is given, then the catchpoint is enabled only for one stop,
the catchpoint is automatically deleted after the first event is caught.

GDB Command
...........

The corresponding GDB commands are 'catch rethrow' and 'tcatch rethrow'
(*note Set Catchpoints::).

Example
.......

     -catch-rethrow -r exception_type
     ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y",
       what="exception rethrow",catch-type="rethrow",
       thread-groups=["i1"],
       regexp="exception_type",times="0"}
     (gdb)
     -exec-run
     ^running
     (gdb)
     ~"\n"
     ~"Catchpoint 1 (exception rethrown), 0x00007ffff7ae00ed
       in __cxa_rethrow () from /lib64/libstdc++.so.6\n"
     *stopped,bkptno="1",reason="breakpoint-hit",disp="keep",
       frame={addr="0x00007ffff7ae00ed",func="__cxa_rethrow",
       args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"},
       thread-id="1",stopped-threads="all",core="6"
     (gdb)

The '-catch-catch' Command
--------------------------

Synopsis
........

      -catch-catch [ -t ] [ -r REGEXP]

   Stop when the debuggee catches a C++ exception.  If REGEXP is given,
then only exceptions whose type matches the regular expression will be
caught.

   If '-t' is given, then the catchpoint is enabled only for one stop,
the catchpoint is automatically deleted after the first event is caught.

GDB Command
...........

The corresponding GDB commands are 'catch catch' and 'tcatch catch'
(*note Set Catchpoints::).

Example
.......

     -catch-catch -r exception_type
     ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y",
       what="exception catch",catch-type="catch",
       thread-groups=["i1"],
       regexp="exception_type",times="0"}
     (gdb)
     -exec-run
     ^running
     (gdb)
     ~"\n"
     ~"Catchpoint 1 (exception caught), 0x00007ffff7ae00ed
       in __cxa_begin_catch () from /lib64/libstdc++.so.6\n"
     *stopped,bkptno="1",reason="breakpoint-hit",disp="keep",
       frame={addr="0x00007ffff7ae00ed",func="__cxa_begin_catch",
       args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"},
       thread-id="1",stopped-threads="all",core="6"
     (gdb)


File: gdb.info,  Node: GDB/MI Program Context,  Next: GDB/MI Thread Commands,  Prev: GDB/MI Catchpoint Commands,  Up: GDB/MI

27.10 GDB/MI Program Context
============================

The '-exec-arguments' Command
-----------------------------

Synopsis
........

      -exec-arguments ARGS

   Set the inferior program arguments, to be used in the next
'-exec-run'.

GDB Command
...........

The corresponding GDB command is 'set args'.

Example
.......

     (gdb)
     -exec-arguments -v word
     ^done
     (gdb)

The '-environment-cd' Command
-----------------------------

Synopsis
........

      -environment-cd PATHDIR

   Set GDB's working directory.

GDB Command
...........

The corresponding GDB command is 'cd'.

Example
.......

     (gdb)
     -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
     ^done
     (gdb)

The '-environment-directory' Command
------------------------------------

Synopsis
........

      -environment-directory [ -r ] [ PATHDIR ]+

   Add directories PATHDIR to beginning of search path for source files.
If the '-r' option is used, the search path is reset to the default
search path.  If directories PATHDIR are supplied in addition to the
'-r' option, the search path is first reset and then addition occurs as
normal.  Multiple directories may be specified, separated by blanks.
Specifying multiple directories in a single command results in the
directories added to the beginning of the search path in the same order
they were presented in the command.  If blanks are needed as part of a
directory name, double-quotes should be used around the name.  In the
command output, the path will show up separated by the system
directory-separator character.  The directory-separator character must
not be used in any directory name.  If no directories are specified, the
current search path is displayed.

GDB Command
...........

The corresponding GDB command is 'dir'.

Example
.......

     (gdb)
     -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
     ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd"
     (gdb)
     -environment-directory ""
     ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd"
     (gdb)
     -environment-directory -r /home/jjohnstn/src/gdb /usr/src
     ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd"
     (gdb)
     -environment-directory -r
     ^done,source-path="$cdir:$cwd"
     (gdb)

The '-environment-path' Command
-------------------------------

Synopsis
........

      -environment-path [ -r ] [ PATHDIR ]+

   Add directories PATHDIR to beginning of search path for object files.
If the '-r' option is used, the search path is reset to the original
search path that existed at gdb start-up.  If directories PATHDIR are
supplied in addition to the '-r' option, the search path is first reset
and then addition occurs as normal.  Multiple directories may be
specified, separated by blanks.  Specifying multiple directories in a
single command results in the directories added to the beginning of the
search path in the same order they were presented in the command.  If
blanks are needed as part of a directory name, double-quotes should be
used around the name.  In the command output, the path will show up
separated by the system directory-separator character.  The
directory-separator character must not be used in any directory name.
If no directories are specified, the current path is displayed.

GDB Command
...........

The corresponding GDB command is 'path'.

Example
.......

     (gdb)
     -environment-path
     ^done,path="/usr/bin"
     (gdb)
     -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin
     ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin"
     (gdb)
     -environment-path -r /usr/local/bin
     ^done,path="/usr/local/bin:/usr/bin"
     (gdb)

The '-environment-pwd' Command
------------------------------

Synopsis
........

      -environment-pwd

   Show the current working directory.

GDB Command
...........

The corresponding GDB command is 'pwd'.

Example
.......

     (gdb)
     -environment-pwd
     ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb"
     (gdb)


File: gdb.info,  Node: GDB/MI Thread Commands,  Next: GDB/MI Ada Tasking Commands,  Prev: GDB/MI Program Context,  Up: GDB/MI

27.11 GDB/MI Thread Commands
============================

The '-thread-info' Command
--------------------------

Synopsis
........

      -thread-info [ THREAD-ID ]

   Reports information about either a specific thread, if the THREAD-ID
parameter is present, or about all threads.  THREAD-ID is the thread's
global thread ID. When printing information about all threads, also
reports the global ID of the current thread.

GDB Command
...........

The 'info thread' command prints the same information about all threads.

Result
......

The result contains the following attributes:

'threads'
     A list of threads.  The format of the elements of the list is
     described in *note GDB/MI Thread Information::.

'current-thread-id'
     The global id of the currently selected thread.  This field is
     omitted if there is no selected thread (for example, when the
     selected inferior is not running, and therefore has no threads) or
     if a THREAD-ID argument was passed to the command.

Example
.......

     -thread-info
     ^done,threads=[
     {id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
        frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",
                args=[]},state="running"},
     {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
        frame={level="0",addr="0x0804891f",func="foo",
                args=[{name="i",value="10"}],
                file="/tmp/a.c",fullname="/tmp/a.c",line="158",arch="i386:x86_64"},
                state="running"}],
     current-thread-id="1"
     (gdb)

The '-thread-list-ids' Command
------------------------------

Synopsis
........

      -thread-list-ids

   Produces a list of the currently known global GDB thread ids.  At the
end of the list it also prints the total number of such threads.

   This command is retained for historical reasons, the '-thread-info'
command should be used instead.

GDB Command
...........

Part of 'info threads' supplies the same information.

Example
.......

     (gdb)
     -thread-list-ids
     ^done,thread-ids={thread-id="3",thread-id="2",thread-id="1"},
     current-thread-id="1",number-of-threads="3"
     (gdb)

The '-thread-select' Command
----------------------------

Synopsis
........

      -thread-select THREAD-ID

   Make thread with global thread number THREAD-ID the current thread.
It prints the number of the new current thread, and the topmost frame
for that thread.

   This command is deprecated in favor of explicitly using the
'--thread' option to each command.

GDB Command
...........

The corresponding GDB command is 'thread'.

Example
.......

     (gdb)
     -exec-next
     ^running
     (gdb)
     *stopped,reason="end-stepping-range",thread-id="2",line="187",
     file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c"
     (gdb)
     -thread-list-ids
     ^done,
     thread-ids={thread-id="3",thread-id="2",thread-id="1"},
     number-of-threads="3"
     (gdb)
     -thread-select 3
     ^done,new-thread-id="3",
     frame={level="0",func="vprintf",
     args=[{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""},
     {name="arg",value="0x2"}],file="vprintf.c",line="31",arch="i386:x86_64"}
     (gdb)


File: gdb.info,  Node: GDB/MI Ada Tasking Commands,  Next: GDB/MI Program Execution,  Prev: GDB/MI Thread Commands,  Up: GDB/MI

27.12 GDB/MI Ada Tasking Commands
=================================

The '-ada-task-info' Command
----------------------------

Synopsis
........

      -ada-task-info [ TASK-ID ]

   Reports information about either a specific Ada task, if the TASK-ID
parameter is present, or about all Ada tasks.

GDB Command
...........

The 'info tasks' command prints the same information about all Ada tasks
(*note Ada Tasks::).

Result
......

The result is a table of Ada tasks.  The following columns are defined
for each Ada task:

'current'
     This field exists only for the current thread.  It has the value
     '*'.

'id'
     The identifier that GDB uses to refer to the Ada task.

'task-id'
     The identifier that the target uses to refer to the Ada task.

'thread-id'
     The global thread identifier of the thread corresponding to the Ada
     task.

     This field should always exist, as Ada tasks are always implemented
     on top of a thread.  But if GDB cannot find this corresponding
     thread for any reason, the field is omitted.

'parent-id'
     This field exists only when the task was created by another task.
     In this case, it provides the ID of the parent task.

'priority'
     The base priority of the task.

'state'
     The current state of the task.  For a detailed description of the
     possible states, see *note Ada Tasks::.

'name'
     The name of the task.

Example
.......

     -ada-task-info
     ^done,tasks={nr_rows="3",nr_cols="8",
     hdr=[{width="1",alignment="-1",col_name="current",colhdr=""},
     {width="3",alignment="1",col_name="id",colhdr="ID"},
     {width="9",alignment="1",col_name="task-id",colhdr="TID"},
     {width="4",alignment="1",col_name="thread-id",colhdr=""},
     {width="4",alignment="1",col_name="parent-id",colhdr="P-ID"},
     {width="3",alignment="1",col_name="priority",colhdr="Pri"},
     {width="22",alignment="-1",col_name="state",colhdr="State"},
     {width="1",alignment="2",col_name="name",colhdr="Name"}],
     body=[{current="*",id="1",task-id="   644010",thread-id="1",priority="48",
     state="Child Termination Wait",name="main_task"}]}
     (gdb)


File: gdb.info,  Node: GDB/MI Program Execution,  Next: GDB/MI Stack Manipulation,  Prev: GDB/MI Ada Tasking Commands,  Up: GDB/MI

27.13 GDB/MI Program Execution
==============================

These are the asynchronous commands which generate the out-of-band
record '*stopped'.  Currently GDB only really executes asynchronously
with remote targets and this interaction is mimicked in other cases.

The '-exec-continue' Command
----------------------------

Synopsis
........

      -exec-continue [--reverse] [--all|--thread-group N]

   Resumes the execution of the inferior program, which will continue to
execute until it reaches a debugger stop event.  If the '--reverse'
option is specified, execution resumes in reverse until it reaches a
stop event.  Stop events may include
   * breakpoints or watchpoints
   * signals or exceptions
   * the end of the process (or its beginning under '--reverse')
   * the end or beginning of a replay log if one is being used.
   In all-stop mode (*note All-Stop Mode::), may resume only one thread,
or all threads, depending on the value of the 'scheduler-locking'
variable.  If '--all' is specified, all threads (in all inferiors) will
be resumed.  The '--all' option is ignored in all-stop mode.  If the
'--thread-group' options is specified, then all threads in that thread
group are resumed.

GDB Command
...........

The corresponding GDB corresponding is 'continue'.

Example
.......

     -exec-continue
     ^running
     (gdb)
     @Hello world
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame={
     func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c",
     line="13",arch="i386:x86_64"}
     (gdb)

   For a 'breakpoint-hit' stopped reason, when the breakpoint
encountered has multiple locations, the field 'bkptno' is followed by
the field 'locno'.

     -exec-continue
     ^running
     (gdb)
     @Hello world
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",locno="3",frame={
     func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c",
     line="13",arch="i386:x86_64"}
     (gdb)

The '-exec-finish' Command
--------------------------

Synopsis
........

      -exec-finish [--reverse]

   Resumes the execution of the inferior program until the current
function is exited.  Displays the results returned by the function.  If
the '--reverse' option is specified, resumes the reverse execution of
the inferior program until the point where current function was called.

GDB Command
...........

The corresponding GDB command is 'finish'.

Example
.......

Function returning 'void'.

     -exec-finish
     ^running
     (gdb)
     @hello from foo
     *stopped,reason="function-finished",frame={func="main",args=[],
     file="hello.c",fullname="/home/foo/bar/hello.c",line="7",arch="i386:x86_64"}
     (gdb)

   Function returning other than 'void'.  The name of the internal GDB
variable storing the result is printed, together with the value itself.

     -exec-finish
     ^running
     (gdb)
     *stopped,reason="function-finished",frame={addr="0x000107b0",func="foo",
     args=[{name="a",value="1"],{name="b",value="9"}},
     file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
     arch="i386:x86_64"},
     gdb-result-var="$1",return-value="0"
     (gdb)

The '-exec-interrupt' Command
-----------------------------

Synopsis
........

      -exec-interrupt [--all|--thread-group N]

   Interrupts the background execution of the target.  Note how the
token associated with the stop message is the one for the execution
command that has been interrupted.  The token for the interrupt itself
only appears in the '^done' output.  If the user is trying to interrupt
a non-running program, an error message will be printed.

   Note that when asynchronous execution is enabled, this command is
asynchronous just like other execution commands.  That is, first the
'^done' response will be printed, and the target stop will be reported
after that using the '*stopped' notification.

   In non-stop mode, only the context thread is interrupted by default.
All threads (in all inferiors) will be interrupted if the '--all' option
is specified.  If the '--thread-group' option is specified, all threads
in that group will be interrupted.

GDB Command
...........

The corresponding GDB command is 'interrupt'.

Example
.......

     (gdb)
     111-exec-continue
     111^running

     (gdb)
     222-exec-interrupt
     222^done
     (gdb)
     111*stopped,signal-name="SIGINT",signal-meaning="Interrupt",
     frame={addr="0x00010140",func="foo",args=[],file="try.c",
     fullname="/home/foo/bar/try.c",line="13",arch="i386:x86_64"}
     (gdb)

     (gdb)
     -exec-interrupt
     ^error,msg="mi_cmd_exec_interrupt: Inferior not executing."
     (gdb)

The '-exec-jump' Command
------------------------

Synopsis
........

      -exec-jump LOCSPEC

   Resumes execution of the inferior program at the address to which
LOCSPEC resolves.  *Note Location Specifications::, for a description of
the different forms of LOCSPEC.

GDB Command
...........

The corresponding GDB command is 'jump'.

Example
.......

     -exec-jump foo.c:10
     *running,thread-id="all"
     ^running

The '-exec-next' Command
------------------------

Synopsis
........

      -exec-next [--reverse]

   Resumes execution of the inferior program, stopping when the
beginning of the next source line is reached.

   If the '--reverse' option is specified, resumes reverse execution of
the inferior program, stopping at the beginning of the previous source
line.  If you issue this command on the first line of a function, it
will take you back to the caller of that function, to the source line
where the function was called.

GDB Command
...........

The corresponding GDB command is 'next'.

Example
.......

     -exec-next
     ^running
     (gdb)
     *stopped,reason="end-stepping-range",line="8",file="hello.c"
     (gdb)

The '-exec-next-instruction' Command
------------------------------------

Synopsis
........

      -exec-next-instruction [--reverse]

   Executes one machine instruction.  If the instruction is a function
call, continues until the function returns.  If the program stops at an
instruction in the middle of a source line, the address will be printed
as well.

   If the '--reverse' option is specified, resumes reverse execution of
the inferior program, stopping at the previous instruction.  If the
previously executed instruction was a return from another function, it
will continue to execute in reverse until the call to that function
(from the current stack frame) is reached.

GDB Command
...........

The corresponding GDB command is 'nexti'.

Example
.......

     (gdb)
     -exec-next-instruction
     ^running

     (gdb)
     *stopped,reason="end-stepping-range",
     addr="0x000100d4",line="5",file="hello.c"
     (gdb)

The '-exec-return' Command
--------------------------

Synopsis
........

      -exec-return

   Makes current function return immediately.  Doesn't execute the
inferior.  Displays the new current frame.

GDB Command
...........

The corresponding GDB command is 'return'.

Example
.......

     (gdb)
     200-break-insert callee4
     200^done,bkpt={number="1",addr="0x00010734",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"}
     (gdb)
     000-exec-run
     000^running
     (gdb)
     000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1",
     frame={func="callee4",args=[],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
     arch="i386:x86_64"}
     (gdb)
     205-break-delete
     205^done
     (gdb)
     111-exec-return
     111^done,frame={level="0",func="callee3",
     args=[{name="strarg",
     value="0x11940 \"A string argument.\""}],
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18",
     arch="i386:x86_64"}
     (gdb)

The '-exec-run' Command
-----------------------

Synopsis
........

      -exec-run [ --all | --thread-group N ] [ --start ]

   Starts execution of the inferior from the beginning.  The inferior
executes until either a breakpoint is encountered or the program exits.
In the latter case the output will include an exit code, if the program
has exited exceptionally.

   When neither the '--all' nor the '--thread-group' option is
specified, the current inferior is started.  If the '--thread-group'
option is specified, it should refer to a thread group of type
'process', and that thread group will be started.  If the '--all' option
is specified, then all inferiors will be started.

   Using the '--start' option instructs the debugger to stop the
execution at the start of the inferior's main subprogram, following the
same behavior as the 'start' command (*note Starting::).

GDB Command
...........

The corresponding GDB command is 'run'.

Examples
........

     (gdb)
     -break-insert main
     ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",line="4"}
     (gdb)
     -exec-run
     ^running
     (gdb)
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",
     frame={func="main",args=[],file="recursive2.c",
     fullname="/home/foo/bar/recursive2.c",line="4",arch="i386:x86_64"}
     (gdb)

Program exited normally:

     (gdb)
     -exec-run
     ^running
     (gdb)
     x = 55
     *stopped,reason="exited-normally"
     (gdb)

Program exited exceptionally:

     (gdb)
     -exec-run
     ^running
     (gdb)
     x = 55
     *stopped,reason="exited",exit-code="01"
     (gdb)

   Another way the program can terminate is if it receives a signal such
as 'SIGINT'.  In this case, GDB/MI displays this:

     (gdb)
     *stopped,reason="exited-signalled",signal-name="SIGINT",
     signal-meaning="Interrupt"

The '-exec-step' Command
------------------------

Synopsis
........

      -exec-step [--reverse]

   Resumes execution of the inferior program, stopping when the
beginning of the next source line is reached, if the next source line is
not a function call.  If it is, stop at the first instruction of the
called function.  If the '--reverse' option is specified, resumes
reverse execution of the inferior program, stopping at the beginning of
the previously executed source line.

GDB Command
...........

The corresponding GDB command is 'step'.

Example
.......

Stepping into a function:

     -exec-step
     ^running
     (gdb)
     *stopped,reason="end-stepping-range",
     frame={func="foo",args=[{name="a",value="10"},
     {name="b",value="0"}],file="recursive2.c",
     fullname="/home/foo/bar/recursive2.c",line="11",arch="i386:x86_64"}
     (gdb)

   Regular stepping:

     -exec-step
     ^running
     (gdb)
     *stopped,reason="end-stepping-range",line="14",file="recursive2.c"
     (gdb)

The '-exec-step-instruction' Command
------------------------------------

Synopsis
........

      -exec-step-instruction [--reverse]

   Resumes the inferior which executes one machine instruction.  If the
'--reverse' option is specified, resumes reverse execution of the
inferior program, stopping at the previously executed instruction.  The
output, once GDB has stopped, will vary depending on whether we have
stopped in the middle of a source line or not.  In the former case, the
address at which the program stopped will be printed as well.

GDB Command
...........

The corresponding GDB command is 'stepi'.

Example
.......

     (gdb)
     -exec-step-instruction
     ^running

     (gdb)
     *stopped,reason="end-stepping-range",
     frame={func="foo",args=[],file="try.c",
     fullname="/home/foo/bar/try.c",line="10",arch="i386:x86_64"}
     (gdb)
     -exec-step-instruction
     ^running

     (gdb)
     *stopped,reason="end-stepping-range",
     frame={addr="0x000100f4",func="foo",args=[],file="try.c",
     fullname="/home/foo/bar/try.c",line="10",arch="i386:x86_64"}
     (gdb)

The '-exec-until' Command
-------------------------

Synopsis
........

      -exec-until [ LOCSPEC ]

   Executes the inferior until it reaches the address to which LOCSPEC
resolves.  If there is no argument, the inferior executes until it
reaches a source line greater than the current one.  The reason for
stopping in this case will be 'location-reached'.

GDB Command
...........

The corresponding GDB command is 'until'.

Example
.......

     (gdb)
     -exec-until recursive2.c:6
     ^running
     (gdb)
     x = 55
     *stopped,reason="location-reached",frame={func="main",args=[],
     file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6",
     arch="i386:x86_64"}
     (gdb)


File: gdb.info,  Node: GDB/MI Stack Manipulation,  Next: GDB/MI Variable Objects,  Prev: GDB/MI Program Execution,  Up: GDB/MI

27.14 GDB/MI Stack Manipulation Commands
========================================

The '-enable-frame-filters' Command
-----------------------------------

     -enable-frame-filters

   GDB allows Python-based frame filters to affect the output of the MI
commands relating to stack traces.  As there is no way to implement this
in a fully backward-compatible way, a front end must request that this
functionality be enabled.

   Once enabled, this feature cannot be disabled.

   Note that if Python support has not been compiled into GDB, this
command will still succeed (and do nothing).

The '-stack-info-frame' Command
-------------------------------

Synopsis
........

      -stack-info-frame

   Get info on the selected frame.

GDB Command
...........

The corresponding GDB command is 'info frame' or 'frame' (without
arguments).

Example
.......

     (gdb)
     -stack-info-frame
     ^done,frame={level="1",addr="0x0001076c",func="callee3",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17",
     arch="i386:x86_64"}
     (gdb)

The '-stack-info-depth' Command
-------------------------------

Synopsis
........

      -stack-info-depth [ MAX-DEPTH ]

   Return the depth of the stack.  If the integer argument MAX-DEPTH is
specified, do not count beyond MAX-DEPTH frames.

GDB Command
...........

There's no equivalent GDB command.

Example
.......

For a stack with frame levels 0 through 11:

     (gdb)
     -stack-info-depth
     ^done,depth="12"
     (gdb)
     -stack-info-depth 4
     ^done,depth="4"
     (gdb)
     -stack-info-depth 12
     ^done,depth="12"
     (gdb)
     -stack-info-depth 11
     ^done,depth="11"
     (gdb)
     -stack-info-depth 13
     ^done,depth="12"
     (gdb)

The '-stack-list-arguments' Command
-----------------------------------

Synopsis
........

      -stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES
         [ LOW-FRAME HIGH-FRAME ]

   Display a list of the arguments for the frames between LOW-FRAME and
HIGH-FRAME (inclusive).  If LOW-FRAME and HIGH-FRAME are not provided,
list the arguments for the whole call stack.  If the two arguments are
equal, show the single frame at the corresponding level.  It is an error
if LOW-FRAME is larger than the actual number of frames.  On the other
hand, HIGH-FRAME may be larger than the actual number of frames, in
which case only existing frames will be returned.

   If PRINT-VALUES is 0 or '--no-values', print only the names of the
variables; if it is 1 or '--all-values', print also their values; and if
it is 2 or '--simple-values', print the name, type and value for simple
data types, and the name and type for arrays, structures and unions.  If
the option '--no-frame-filters' is supplied, then Python frame filters
will not be executed.

   If the '--skip-unavailable' option is specified, arguments that are
not available are not listed.  Partially available arguments are still
displayed, however.

   Use of this command to obtain arguments in a single frame is
deprecated in favor of the '-stack-list-variables' command.

GDB Command
...........

GDB does not have an equivalent command.  'gdbtk' has a 'gdb_get_args'
command which partially overlaps with the functionality of
'-stack-list-arguments'.

Example
.......

     (gdb)
     -stack-list-frames
     ^done,
     stack=[
     frame={level="0",addr="0x00010734",func="callee4",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
     arch="i386:x86_64"},
     frame={level="1",addr="0x0001076c",func="callee3",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17",
     arch="i386:x86_64"},
     frame={level="2",addr="0x0001078c",func="callee2",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22",
     arch="i386:x86_64"},
     frame={level="3",addr="0x000107b4",func="callee1",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27",
     arch="i386:x86_64"},
     frame={level="4",addr="0x000107e0",func="main",
     file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
     fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32",
     arch="i386:x86_64"}]
     (gdb)
     -stack-list-arguments 0
     ^done,
     stack-args=[
     frame={level="0",args=[]},
     frame={level="1",args=[name="strarg"]},
     frame={level="2",args=[name="intarg",name="strarg"]},
     frame={level="3",args=[name="intarg",name="strarg",name="fltarg"]},
     frame={level="4",args=[]}]
     (gdb)
     -stack-list-arguments 1
     ^done,
     stack-args=[
     frame={level="0",args=[]},
     frame={level="1",
      args=[{name="strarg",value="0x11940 \"A string argument.\""}]},
     frame={level="2",args=[
     {name="intarg",value="2"},
     {name="strarg",value="0x11940 \"A string argument.\""}]},
     {frame={level="3",args=[
     {name="intarg",value="2"},
     {name="strarg",value="0x11940 \"A string argument.\""},
     {name="fltarg",value="3.5"}]},
     frame={level="4",args=[]}]
     (gdb)
     -stack-list-arguments 0 2 2
     ^done,stack-args=[frame={level="2",args=[name="intarg",name="strarg"]}]
     (gdb)
     -stack-list-arguments 1 2 2
     ^done,stack-args=[frame={level="2",
     args=[{name="intarg",value="2"},
     {name="strarg",value="0x11940 \"A string argument.\""}]}]
     (gdb)

The '-stack-list-frames' Command
--------------------------------

Synopsis
........

      -stack-list-frames [ --no-frame-filters LOW-FRAME HIGH-FRAME ]

   List the frames currently on the stack.  For each frame it displays
the following info:

'LEVEL'
     The frame number, 0 being the topmost frame, i.e., the innermost
     function.
'ADDR'
     The '$pc' value for that frame.
'FUNC'
     Function name.
'FILE'
     File name of the source file where the function lives.
'FULLNAME'
     The full file name of the source file where the function lives.
'LINE'
     Line number corresponding to the '$pc'.
'FROM'
     The shared library where this function is defined.  This is only
     given if the frame's function is not known.
'ARCH'
     Frame's architecture.

   If invoked without arguments, this command prints a backtrace for the
whole stack.  If given two integer arguments, it shows the frames whose
levels are between the two arguments (inclusive).  If the two arguments
are equal, it shows the single frame at the corresponding level.  It is
an error if LOW-FRAME is larger than the actual number of frames.  On
the other hand, HIGH-FRAME may be larger than the actual number of
frames, in which case only existing frames will be returned.  If the
option '--no-frame-filters' is supplied, then Python frame filters will
not be executed.

GDB Command
...........

The corresponding GDB commands are 'backtrace' and 'where'.

Example
.......

Full stack backtrace:

     (gdb)
     -stack-list-frames
     ^done,stack=
     [frame={level="0",addr="0x0001076c",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11",
       arch="i386:x86_64"},
     frame={level="1",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="2",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="3",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="4",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="5",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="6",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="7",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="8",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="9",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="10",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="11",addr="0x00010738",func="main",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4",
       arch="i386:x86_64"}]
     (gdb)

   Show frames between LOW_FRAME and HIGH_FRAME:

     (gdb)
     -stack-list-frames 3 5
     ^done,stack=
     [frame={level="3",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="4",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"},
     frame={level="5",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"}]
     (gdb)

   Show a single frame:

     (gdb)
     -stack-list-frames 3 3
     ^done,stack=
     [frame={level="3",addr="0x000107a4",func="foo",
       file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
       arch="i386:x86_64"}]
     (gdb)

The '-stack-list-locals' Command
--------------------------------

Synopsis
........

      -stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES

   Display the local variable names for the selected frame.  If
PRINT-VALUES is 0 or '--no-values', print only the names of the
variables; if it is 1 or '--all-values', print also their values; and if
it is 2 or '--simple-values', print the name, type and value for simple
data types, and the name and type for arrays, structures and unions.  In
this last case, a frontend can immediately display the value of simple
data types and create variable objects for other data types when the
user wishes to explore their values in more detail.  If the option
'--no-frame-filters' is supplied, then Python frame filters will not be
executed.

   If the '--skip-unavailable' option is specified, local variables that
are not available are not listed.  Partially available local variables
are still displayed, however.

   This command is deprecated in favor of the '-stack-list-variables'
command.

GDB Command
...........

'info locals' in GDB, 'gdb_get_locals' in 'gdbtk'.

Example
.......

     (gdb)
     -stack-list-locals 0
     ^done,locals=[name="A",name="B",name="C"]
     (gdb)
     -stack-list-locals --all-values
     ^done,locals=[{name="A",value="1"},{name="B",value="2"},
       {name="C",value="{1, 2, 3}"}]
     -stack-list-locals --simple-values
     ^done,locals=[{name="A",type="int",value="1"},
       {name="B",type="int",value="2"},{name="C",type="int [3]"}]
     (gdb)

The '-stack-list-variables' Command
-----------------------------------

Synopsis
........

      -stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES

   Display the names of local variables and function arguments for the
selected frame.  If PRINT-VALUES is 0 or '--no-values', print only the
names of the variables; if it is 1 or '--all-values', print also their
values; and if it is 2 or '--simple-values', print the name, type and
value for simple data types, and the name and type for arrays,
structures and unions.  If the option '--no-frame-filters' is supplied,
then Python frame filters will not be executed.

   If the '--skip-unavailable' option is specified, local variables and
arguments that are not available are not listed.  Partially available
arguments and local variables are still displayed, however.

Example
.......

     (gdb)
     -stack-list-variables --thread 1 --frame 0 --all-values
     ^done,variables=[{name="x",value="11"},{name="s",value="{a = 1, b = 2}"}]
     (gdb)

The '-stack-select-frame' Command
---------------------------------

Synopsis
........

      -stack-select-frame FRAMENUM

   Change the selected frame.  Select a different frame FRAMENUM on the
stack.

   This command in deprecated in favor of passing the '--frame' option
to every command.

GDB Command
...........

The corresponding GDB commands are 'frame', 'up', 'down',
'select-frame', 'up-silent', and 'down-silent'.

Example
.......

     (gdb)
     -stack-select-frame 2
     ^done
     (gdb)


File: gdb.info,  Node: GDB/MI Variable Objects,  Next: GDB/MI Data Manipulation,  Prev: GDB/MI Stack Manipulation,  Up: GDB/MI

27.15 GDB/MI Variable Objects
=============================

Introduction to Variable Objects
--------------------------------

Variable objects are "object-oriented" MI interface for examining and
changing values of expressions.  Unlike some other MI interfaces that
work with expressions, variable objects are specifically designed for
simple and efficient presentation in the frontend.  A variable object is
identified by string name.  When a variable object is created, the
frontend specifies the expression for that variable object.  The
expression can be a simple variable, or it can be an arbitrary complex
expression, and can even involve CPU registers.  After creating a
variable object, the frontend can invoke other variable object
operations--for example to obtain or change the value of a variable
object, or to change display format.

   Variable objects have hierarchical tree structure.  Any variable
object that corresponds to a composite type, such as structure in C, has
a number of child variable objects, for example corresponding to each
element of a structure.  A child variable object can itself have
children, recursively.  Recursion ends when we reach leaf variable
objects, which always have built-in types.  Child variable objects are
created only by explicit request, so if a frontend is not interested in
the children of a particular variable object, no child will be created.

   For a leaf variable object it is possible to obtain its value as a
string, or set the value from a string.  String value can be also
obtained for a non-leaf variable object, but it's generally a string
that only indicates the type of the object, and does not list its
contents.  Assignment to a non-leaf variable object is not allowed.

   A frontend does not need to read the values of all variable objects
each time the program stops.  Instead, MI provides an update command
that lists all variable objects whose values has changed since the last
update operation.  This considerably reduces the amount of data that
must be transferred to the frontend.  As noted above, children variable
objects are created on demand, and only leaf variable objects have a
real value.  As result, gdb will read target memory only for leaf
variables that frontend has created.

   The automatic update is not always desirable.  For example, a
frontend might want to keep a value of some expression for future
reference, and never update it.  For another example, fetching memory is
relatively slow for embedded targets, so a frontend might want to
disable automatic update for the variables that are either not visible
on the screen, or "closed".  This is possible using so called "frozen
variable objects".  Such variable objects are never implicitly updated.

   Variable objects can be either "fixed" or "floating".  For the fixed
variable object, the expression is parsed when the variable object is
created, including associating identifiers to specific variables.  The
meaning of expression never changes.  For a floating variable object the
values of variables whose names appear in the expressions are
re-evaluated every time in the context of the current frame.  Consider
this example:

     void do_work(...)
     {
             struct work_state state;

             if (...)
                do_work(...);
     }

   If a fixed variable object for the 'state' variable is created in
this function, and we enter the recursive call, the variable object will
report the value of 'state' in the top-level 'do_work' invocation.  On
the other hand, a floating variable object will report the value of
'state' in the current frame.

   If an expression specified when creating a fixed variable object
refers to a local variable, the variable object becomes bound to the
thread and frame in which the variable object is created.  When such
variable object is updated, GDB makes sure that the thread/frame
combination the variable object is bound to still exists, and
re-evaluates the variable object in context of that thread/frame.

   The following is the complete set of GDB/MI operations defined to
access this functionality:

*Operation*                   *Description*
                              
'-enable-pretty-printing'     enable Python-based pretty-printing
'-var-create'                 create a variable object
'-var-delete'                 delete the variable object and/or its
                              children
'-var-set-format'             set the display format of this variable
'-var-show-format'            show the display format of this variable
'-var-info-num-children'      tells how many children this object has
'-var-list-children'          return a list of the object's children
'-var-info-type'              show the type of this variable object
'-var-info-expression'        print parent-relative expression that
                              this variable object represents
'-var-info-path-expression'   print full expression that this variable
                              object represents
'-var-show-attributes'        is this variable editable?  does it exist
                              here?
'-var-evaluate-expression'    get the value of this variable
'-var-assign'                 set the value of this variable
'-var-update'                 update the variable and its children
'-var-set-frozen'             set frozenness attribute
'-var-set-update-range'       set range of children to display on
                              update

   In the next subsection we describe each operation in detail and
suggest how it can be used.

Description And Use of Operations on Variable Objects
-----------------------------------------------------

The '-enable-pretty-printing' Command
-------------------------------------

     -enable-pretty-printing

   GDB allows Python-based visualizers to affect the output of the MI
variable object commands.  However, because there was no way to
implement this in a fully backward-compatible way, a front end must
request that this functionality be enabled.

   Once enabled, this feature cannot be disabled.

   Note that if Python support has not been compiled into GDB, this
command will still succeed (and do nothing).

The '-var-create' Command
-------------------------

Synopsis
........

      -var-create {NAME | "-"}
         {FRAME-ADDR | "*" | "@"} EXPRESSION

   This operation creates a variable object, which allows the monitoring
of a variable, the result of an expression, a memory cell or a CPU
register.

   The NAME parameter is the string by which the object can be
referenced.  It must be unique.  If '-' is specified, the varobj system
will generate a string "varNNNNNN" automatically.  It will be unique
provided that one does not specify NAME of that format.  The command
fails if a duplicate name is found.

   The frame under which the expression should be evaluated can be
specified by FRAME-ADDR.  A '*' indicates that the current frame should
be used.  A '@' indicates that a floating variable object must be
created.

   EXPRESSION is any expression valid on the current language set (must
not begin with a '*'), or one of the following:

   * '*ADDR', where ADDR is the address of a memory cell

   * '*ADDR-ADDR' -- a memory address range (TBD)

   * '$REGNAME' -- a CPU register name

   A varobj's contents may be provided by a Python-based pretty-printer.
In this case the varobj is known as a "dynamic varobj".  Dynamic varobjs
have slightly different semantics in some cases.  If the
'-enable-pretty-printing' command is not sent, then GDB will never
create a dynamic varobj.  This ensures backward compatibility for
existing clients.

Result
......

This operation returns attributes of the newly-created varobj.  These
are:

'name'
     The name of the varobj.

'numchild'
     The number of children of the varobj.  This number is not
     necessarily reliable for a dynamic varobj.  Instead, you must
     examine the 'has_more' attribute.

'value'
     The varobj's scalar value.  For a varobj whose type is some sort of
     aggregate (e.g., a 'struct'), or for a dynamic varobj, this value
     will not be interesting.

'type'
     The varobj's type.  This is a string representation of the type, as
     would be printed by the GDB CLI. If 'print object' (*note set print
     object: Print Settings.) is set to 'on', the _actual_ (derived)
     type of the object is shown rather than the _declared_ one.

'thread-id'
     If a variable object is bound to a specific thread, then this is
     the thread's global identifier.

'has_more'
     For a dynamic varobj, this indicates whether there appear to be any
     children available.  For a non-dynamic varobj, this will be 0.

'dynamic'
     This attribute will be present and have the value '1' if the varobj
     is a dynamic varobj.  If the varobj is not a dynamic varobj, then
     this attribute will not be present.

'displayhint'
     A dynamic varobj can supply a display hint to the front end.  The
     value comes directly from the Python pretty-printer object's
     'display_hint' method.  *Note Pretty Printing API::.

   Typical output will look like this:

      name="NAME",numchild="N",type="TYPE",thread-id="M",
       has_more="HAS_MORE"

The '-var-delete' Command
-------------------------

Synopsis
........

      -var-delete [ -c ] NAME

   Deletes a previously created variable object and all of its children.
With the '-c' option, just deletes the children.

   Returns an error if the object NAME is not found.

The '-var-set-format' Command
-----------------------------

Synopsis
........

      -var-set-format NAME FORMAT-SPEC

   Sets the output format for the value of the object NAME to be
FORMAT-SPEC.

   The syntax for the FORMAT-SPEC is as follows:

      FORMAT-SPEC ==>
      {binary | decimal | hexadecimal | octal | natural | zero-hexadecimal}

   The natural format is the default format choosen automatically based
on the variable type (like decimal for an 'int', hex for pointers,
etc.).

   The zero-hexadecimal format has a representation similar to
hexadecimal but with padding zeroes to the left of the value.  For
example, a 32-bit hexadecimal value of 0x1234 would be represented as
0x00001234 in the zero-hexadecimal format.

   For a variable with children, the format is set only on the variable
itself, and the children are not affected.

The '-var-show-format' Command
------------------------------

Synopsis
........

      -var-show-format NAME

   Returns the format used to display the value of the object NAME.

      FORMAT ==>
      FORMAT-SPEC

The '-var-info-num-children' Command
------------------------------------

Synopsis
........

      -var-info-num-children NAME

   Returns the number of children of a variable object NAME:

      numchild=N

   Note that this number is not completely reliable for a dynamic
varobj.  It will return the current number of children, but more
children may be available.

The '-var-list-children' Command
--------------------------------

Synopsis
........

      -var-list-children [PRINT-VALUES] NAME [FROM TO]

   Return a list of the children of the specified variable object and
create variable objects for them, if they do not already exist.  With a
single argument or if PRINT-VALUES has a value of 0 or '--no-values',
print only the names of the variables; if PRINT-VALUES is 1 or
'--all-values', also print their values; and if it is 2 or
'--simple-values' print the name and value for simple data types and
just the name for arrays, structures and unions.

   FROM and TO, if specified, indicate the range of children to report.
If FROM or TO is less than zero, the range is reset and all children
will be reported.  Otherwise, children starting at FROM (zero-based) and
up to and excluding TO will be reported.

   If a child range is requested, it will only affect the current call
to '-var-list-children', but not future calls to '-var-update'.  For
this, you must instead use '-var-set-update-range'.  The intent of this
approach is to enable a front end to implement any update approach it
likes; for example, scrolling a view may cause the front end to request
more children with '-var-list-children', and then the front end could
call '-var-set-update-range' with a different range to ensure that
future updates are restricted to just the visible items.

   For each child the following results are returned:

NAME
     Name of the variable object created for this child.

EXP
     The expression to be shown to the user by the front end to
     designate this child.  For example this may be the name of a
     structure member.

     For a dynamic varobj, this value cannot be used to form an
     expression.  There is no way to do this at all with a dynamic
     varobj.

     For C/C++ structures there are several pseudo children returned to
     designate access qualifiers.  For these pseudo children EXP is
     'public', 'private', or 'protected'.  In this case the type and
     value are not present.

     A dynamic varobj will not report the access qualifying
     pseudo-children, regardless of the language.  This information is
     not available at all with a dynamic varobj.

NUMCHILD
     Number of children this child has.  For a dynamic varobj, this will
     be 0.

TYPE
     The type of the child.  If 'print object' (*note set print object:
     Print Settings.) is set to 'on', the _actual_ (derived) type of the
     object is shown rather than the _declared_ one.

VALUE
     If values were requested, this is the value.

THREAD-ID
     If this variable object is associated with a thread, this is the
     thread's global thread id.  Otherwise this result is not present.

FROZEN
     If the variable object is frozen, this variable will be present
     with a value of 1.

DISPLAYHINT
     A dynamic varobj can supply a display hint to the front end.  The
     value comes directly from the Python pretty-printer object's
     'display_hint' method.  *Note Pretty Printing API::.

DYNAMIC
     This attribute will be present and have the value '1' if the varobj
     is a dynamic varobj.  If the varobj is not a dynamic varobj, then
     this attribute will not be present.

   The result may have its own attributes:

'displayhint'
     A dynamic varobj can supply a display hint to the front end.  The
     value comes directly from the Python pretty-printer object's
     'display_hint' method.  *Note Pretty Printing API::.

'has_more'
     This is an integer attribute which is nonzero if there are children
     remaining after the end of the selected range.

Example
.......

     (gdb)
      -var-list-children n
      ^done,numchild=N,children=[child={name=NAME,exp=EXP,
      numchild=N,type=TYPE},(repeats N times)]
     (gdb)
      -var-list-children --all-values n
      ^done,numchild=N,children=[child={name=NAME,exp=EXP,
      numchild=N,value=VALUE,type=TYPE},(repeats N times)]

The '-var-info-type' Command
----------------------------

Synopsis
........

      -var-info-type NAME

   Returns the type of the specified variable NAME.  The type is
returned as a string in the same format as it is output by the GDB CLI:

      type=TYPENAME

The '-var-info-expression' Command
----------------------------------

Synopsis
........

      -var-info-expression NAME

   Returns a string that is suitable for presenting this variable object
in user interface.  The string is generally not valid expression in the
current language, and cannot be evaluated.

   For example, if 'a' is an array, and variable object 'A' was created
for 'a', then we'll get this output:

     (gdb) -var-info-expression A.1
     ^done,lang="C",exp="1"

Here, the value of 'lang' is the language name, which can be found in
*note Supported Languages::.

   Note that the output of the '-var-list-children' command also
includes those expressions, so the '-var-info-expression' command is of
limited use.

The '-var-info-path-expression' Command
---------------------------------------

Synopsis
........

      -var-info-path-expression NAME

   Returns an expression that can be evaluated in the current context
and will yield the same value that a variable object has.  Compare this
with the '-var-info-expression' command, which result can be used only
for UI presentation.  Typical use of the '-var-info-path-expression'
command is creating a watchpoint from a variable object.

   This command is currently not valid for children of a dynamic varobj,
and will give an error when invoked on one.

   For example, suppose 'C' is a C++ class, derived from class 'Base',
and that the 'Base' class has a member called 'm_size'.  Assume a
variable 'c' is has the type of 'C' and a variable object 'C' was
created for variable 'c'.  Then, we'll get this output:
     (gdb) -var-info-path-expression C.Base.public.m_size
     ^done,path_expr=((Base)c).m_size)

The '-var-show-attributes' Command
----------------------------------

Synopsis
........

      -var-show-attributes NAME

   List attributes of the specified variable object NAME:

      status=ATTR [ ( ,ATTR )* ]

where ATTR is '{ { editable | noneditable } | TBD }'.

The '-var-evaluate-expression' Command
--------------------------------------

Synopsis
........

      -var-evaluate-expression [-f FORMAT-SPEC] NAME

   Evaluates the expression that is represented by the specified
variable object and returns its value as a string.  The format of the
string can be specified with the '-f' option.  The possible values of
this option are the same as for '-var-set-format' (*note
-var-set-format::).  If the '-f' option is not specified, the current
display format will be used.  The current display format can be changed
using the '-var-set-format' command.

      value=VALUE

   Note that one must invoke '-var-list-children' for a variable before
the value of a child variable can be evaluated.

The '-var-assign' Command
-------------------------

Synopsis
........

      -var-assign NAME EXPRESSION

   Assigns the value of EXPRESSION to the variable object specified by
NAME.  The object must be 'editable'.  If the variable's value is
altered by the assign, the variable will show up in any subsequent
'-var-update' list.

Example
.......

     (gdb)
     -var-assign var1 3
     ^done,value="3"
     (gdb)
     -var-update *
     ^done,changelist=[{name="var1",in_scope="true",type_changed="false"}]
     (gdb)

The '-var-update' Command
-------------------------

Synopsis
........

      -var-update [PRINT-VALUES] {NAME | "*"}

   Reevaluate the expressions corresponding to the variable object NAME
and all its direct and indirect children, and return the list of
variable objects whose values have changed; NAME must be a root variable
object.  Here, "changed" means that the result of
'-var-evaluate-expression' before and after the '-var-update' is
different.  If '*' is used as the variable object names, all existing
variable objects are updated, except for frozen ones (*note
-var-set-frozen::).  The option PRINT-VALUES determines whether both
names and values, or just names are printed.  The possible values of
this option are the same as for '-var-list-children' (*note
-var-list-children::).  It is recommended to use the '--all-values'
option, to reduce the number of MI commands needed on each program stop.

   With the '*' parameter, if a variable object is bound to a currently
running thread, it will not be updated, without any diagnostic.

   If '-var-set-update-range' was previously used on a varobj, then only
the selected range of children will be reported.

   '-var-update' reports all the changed varobjs in a tuple named
'changelist'.

   Each item in the change list is itself a tuple holding:

'name'
     The name of the varobj.

'value'
     If values were requested for this update, then this field will be
     present and will hold the value of the varobj.

'in_scope'
     This field is a string which may take one of three values:

     '"true"'
          The variable object's current value is valid.

     '"false"'
          The variable object does not currently hold a valid value but
          it may hold one in the future if its associated expression
          comes back into scope.

     '"invalid"'
          The variable object no longer holds a valid value.  This can
          occur when the executable file being debugged has changed,
          either through recompilation or by using the GDB 'file'
          command.  The front end should normally choose to delete these
          variable objects.

     In the future new values may be added to this list so the front
     should be prepared for this possibility.  *Note GDB/MI Development
     and Front Ends: GDB/MI Development and Front Ends.

'type_changed'
     This is only present if the varobj is still valid.  If the type
     changed, then this will be the string 'true'; otherwise it will be
     'false'.

     When a varobj's type changes, its children are also likely to have
     become incorrect.  Therefore, the varobj's children are
     automatically deleted when this attribute is 'true'.  Also, the
     varobj's update range, when set using the '-var-set-update-range'
     command, is unset.

'new_type'
     If the varobj's type changed, then this field will be present and
     will hold the new type.

'new_num_children'
     For a dynamic varobj, if the number of children changed, or if the
     type changed, this will be the new number of children.

     The 'numchild' field in other varobj responses is generally not
     valid for a dynamic varobj - it will show the number of children
     that GDB knows about, but because dynamic varobjs lazily
     instantiate their children, this will not reflect the number of
     children which may be available.

     The 'new_num_children' attribute only reports changes to the number
     of children known by GDB.  This is the only way to detect whether
     an update has removed children (which necessarily can only happen
     at the end of the update range).

'displayhint'
     The display hint, if any.

'has_more'
     This is an integer value, which will be 1 if there are more
     children available outside the varobj's update range.

'dynamic'
     This attribute will be present and have the value '1' if the varobj
     is a dynamic varobj.  If the varobj is not a dynamic varobj, then
     this attribute will not be present.

'new_children'
     If new children were added to a dynamic varobj within the selected
     update range (as set by '-var-set-update-range'), then they will be
     listed in this attribute.

Example
.......

     (gdb)
     -var-assign var1 3
     ^done,value="3"
     (gdb)
     -var-update --all-values var1
     ^done,changelist=[{name="var1",value="3",in_scope="true",
     type_changed="false"}]
     (gdb)

The '-var-set-frozen' Command
-----------------------------

Synopsis
........

      -var-set-frozen NAME FLAG

   Set the frozenness flag on the variable object NAME.  The FLAG
parameter should be either '1' to make the variable frozen or '0' to
make it unfrozen.  If a variable object is frozen, then neither itself,
nor any of its children, are implicitly updated by '-var-update' of a
parent variable or by '-var-update *'.  Only '-var-update' of the
variable itself will update its value and values of its children.  After
a variable object is unfrozen, it is implicitly updated by all
subsequent '-var-update' operations.  Unfreezing a variable does not
update it, only subsequent '-var-update' does.

Example
.......

     (gdb)
     -var-set-frozen V 1
     ^done
     (gdb)

The '-var-set-update-range' command
-----------------------------------

Synopsis
........

      -var-set-update-range NAME FROM TO

   Set the range of children to be returned by future invocations of
'-var-update'.

   FROM and TO indicate the range of children to report.  If FROM or TO
is less than zero, the range is reset and all children will be reported.
Otherwise, children starting at FROM (zero-based) and up to and
excluding TO will be reported.

Example
.......

     (gdb)
     -var-set-update-range V 1 2
     ^done

The '-var-set-visualizer' command
---------------------------------

Synopsis
........

      -var-set-visualizer NAME VISUALIZER

   Set a visualizer for the variable object NAME.

   VISUALIZER is the visualizer to use.  The special value 'None' means
to disable any visualizer in use.

   If not 'None', VISUALIZER must be a Python expression.  This
expression must evaluate to a callable object which accepts a single
argument.  GDB will call this object with the value of the varobj NAME
as an argument (this is done so that the same Python pretty-printing
code can be used for both the CLI and MI). When called, this object must
return an object which conforms to the pretty-printing interface (*note
Pretty Printing API::).

   The pre-defined function 'gdb.default_visualizer' may be used to
select a visualizer by following the built-in process (*note Selecting
Pretty-Printers::).  This is done automatically when a varobj is
created, and so ordinarily is not needed.

   This feature is only available if Python support is enabled.  The MI
command '-list-features' (*note GDB/MI Support Commands::) can be used
to check this.

Example
.......

Resetting the visualizer:

     (gdb)
     -var-set-visualizer V None
     ^done

   Reselecting the default (type-based) visualizer:

     (gdb)
     -var-set-visualizer V gdb.default_visualizer
     ^done

   Suppose 'SomeClass' is a visualizer class.  A lambda expression can
be used to instantiate this class for a varobj:

     (gdb)
     -var-set-visualizer V "lambda val: SomeClass()"
     ^done


File: gdb.info,  Node: GDB/MI Data Manipulation,  Next: GDB/MI Tracepoint Commands,  Prev: GDB/MI Variable Objects,  Up: GDB/MI

27.16 GDB/MI Data Manipulation
==============================

This section describes the GDB/MI commands that manipulate data: examine
memory and registers, evaluate expressions, etc.

   For details about what an addressable memory unit is, *note
addressable memory unit::.

The '-data-disassemble' Command
-------------------------------

Synopsis
........

      -data-disassemble
       ( -s START-ADDR -e END-ADDR
       | -a ADDR
       | -f FILENAME -l LINENUM [ -n LINES ] )
       [ --opcodes OPCODES-MODE ]
       [ --source ]
       [ -- MODE ]

Where:

'START-ADDR'
     is the beginning address (or '$pc')
'END-ADDR'
     is the end address
'ADDR'
     is an address anywhere within (or the name of) the function to
     disassemble.  If an address is specified, the whole function
     surrounding that address will be disassembled.  If a name is
     specified, the whole function with that name will be disassembled.
'FILENAME'
     is the name of the file to disassemble
'LINENUM'
     is the line number to disassemble around
'LINES'
     is the number of disassembly lines to be produced.  If it is -1,
     the whole function will be disassembled, in case no END-ADDR is
     specified.  If END-ADDR is specified as a non-zero value, and LINES
     is lower than the number of disassembly lines between START-ADDR
     and END-ADDR, only LINES lines are displayed; if LINES is higher
     than the number of lines between START-ADDR and END-ADDR, only the
     lines up to END-ADDR are displayed.
'OPCODES-MODE'
     can only be used with MODE 0, and should be one of the following:
     'none'
          no opcode information will be included in the result.

     'bytes'
          opcodes will be included in the result, the opcodes will be
          formatted as for 'disassemble /b'.

     'display'
          opcodes will be included in the result, the opcodes will be
          formatted as for 'disassemble /r'.
'MODE'
     the use of MODE is deprecated in favour of using the '--opcodes'
     and '--source' options.  When no MODE is given, MODE 0 will be
     assumed.  However, the MODE is still available for backward
     compatibility.  The MODE should be one of:
     '0'
          _disassembly only_, this is the default mode if no mode is
          specified.

     '1'
          _mixed source and disassembly (deprecated)_, it is not
          possible to recreate this mode using '--opcodes' and
          '--source' options.

     '2'
          _disassembly with raw opcodes_, this mode is equivalent to
          using MODE 0 and passing '--opcodes bytes' to the command.

     '3'
          _mixed source and disassembly with raw opcodes (deprecated)_,
          it is not possible to recreate this mode using '--opcodes' and
          '--source' options.

     '4'
          _mixed source and disassembly_, this mode is equivalent to
          using MODE 0 and passing '--source' to the command.

     '5'
          _mixed source and disassembly with raw opcodes_, this mode is
          equivalent to using MODE 0 and passing '--opcodes bytes' and
          '--source' to the command.
     Modes 1 and 3 are deprecated.  The output is "source centric" which
     hasn't proved useful in practice.  *Note Machine Code::, for a
     discussion of the difference between '/m' and '/s' output of the
     'disassemble' command.

   The '--source' can only be used with MODE 0.  Passing this option
will include the source code in the disassembly result as if MODE 4 or 5
had been used.

Result
......

The result of the '-data-disassemble' command will be a list named
'asm_insns', the contents of this list depend on the options used with
the '-data-disassemble' command.

   For modes 0 and 2, and when the '--source' option is not used, the
'asm_insns' list contains tuples with the following fields:

'address'
     The address at which this instruction was disassembled.

'func-name'
     The name of the function this instruction is within.

'offset'
     The decimal offset in bytes from the start of 'func-name'.

'inst'
     The text disassembly for this 'address'.

'opcodes'
     This field is only present for modes 2, 3 and 5, or when the
     '--opcodes' option 'bytes' or 'display' is used.  This contains the
     raw opcode bytes for the 'inst' field.

     When the '--opcodes' option is not passed to '-data-disassemble',
     or the 'bytes' value is passed to '--opcodes', then the bytes are
     formatted as a series of single bytes, in hex, in ascending address
     order, with a single space between each byte.  This format is
     equivalent to the '/b' option being used with the 'disassemble'
     command (*note 'disassemble': disassemble.).

     When '--opcodes' is passed the value 'display' then the bytes are
     formatted in the natural instruction display order.  This means
     multiple bytes can be grouped together, and the bytes might be
     byte-swapped.  This format is equivalent to the '/r' option being
     used with the 'disassemble' command.

   For modes 1, 3, 4 and 5, or when the '--source' option is used, the
'asm_insns' list contains tuples named 'src_and_asm_line', each of which
has the following fields:

'line'
     The line number within 'file'.

'file'
     The file name from the compilation unit.  This might be an absolute
     file name or a relative file name depending on the compile command
     used.

'fullname'
     Absolute file name of 'file'.  It is converted to a canonical form
     using the source file search path (*note Specifying Source
     Directories: Source Path.) and after resolving all the symbolic
     links.

     If the source file is not found this field will contain the path as
     present in the debug information.

'line_asm_insn'
     This is a list of tuples containing the disassembly for 'line' in
     'file'.  The fields of each tuple are the same as for
     '-data-disassemble' in MODE 0 and 2, so 'address', 'func-name',
     'offset', 'inst', and optionally 'opcodes'.

   Note that whatever included in the 'inst' field, is not manipulated
directly by GDB/MI, i.e., it is not possible to adjust its format.

GDB Command
...........

The corresponding GDB command is 'disassemble'.

Example
.......

Disassemble from the current value of '$pc' to '$pc + 20':

     (gdb)
     -data-disassemble -s $pc -e "$pc + 20" -- 0
     ^done,
     asm_insns=[
     {address="0x000107c0",func-name="main",offset="4",
     inst="mov  2, %o0"},
     {address="0x000107c4",func-name="main",offset="8",
     inst="sethi  %hi(0x11800), %o2"},
     {address="0x000107c8",func-name="main",offset="12",
     inst="or  %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"},
     {address="0x000107cc",func-name="main",offset="16",
     inst="sethi  %hi(0x11800), %o2"},
     {address="0x000107d0",func-name="main",offset="20",
     inst="or  %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"}]
     (gdb)

   Disassemble the whole 'main' function.  Line 32 is part of 'main'.

     -data-disassemble -f basics.c -l 32 -- 0
     ^done,asm_insns=[
     {address="0x000107bc",func-name="main",offset="0",
     inst="save  %sp, -112, %sp"},
     {address="0x000107c0",func-name="main",offset="4",
     inst="mov   2, %o0"},
     {address="0x000107c4",func-name="main",offset="8",
     inst="sethi %hi(0x11800), %o2"},
     [...]
     {address="0x0001081c",func-name="main",offset="96",inst="ret "},
     {address="0x00010820",func-name="main",offset="100",inst="restore "}]
     (gdb)

   Disassemble 3 instructions from the start of 'main':

     (gdb)
     -data-disassemble -f basics.c -l 32 -n 3 -- 0
     ^done,asm_insns=[
     {address="0x000107bc",func-name="main",offset="0",
     inst="save  %sp, -112, %sp"},
     {address="0x000107c0",func-name="main",offset="4",
     inst="mov  2, %o0"},
     {address="0x000107c4",func-name="main",offset="8",
     inst="sethi  %hi(0x11800), %o2"}]
     (gdb)

   Disassemble 3 instructions from the start of 'main' in mixed mode:

     (gdb)
     -data-disassemble -f basics.c -l 32 -n 3 -- 1
     ^done,asm_insns=[
     src_and_asm_line={line="31",
     file="../../../src/gdb/testsuite/gdb.mi/basics.c",
     fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c",
     line_asm_insn=[{address="0x000107bc",
     func-name="main",offset="0",inst="save  %sp, -112, %sp"}]},
     src_and_asm_line={line="32",
     file="../../../src/gdb/testsuite/gdb.mi/basics.c",
     fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c",
     line_asm_insn=[{address="0x000107c0",
     func-name="main",offset="4",inst="mov  2, %o0"},
     {address="0x000107c4",func-name="main",offset="8",
     inst="sethi  %hi(0x11800), %o2"}]}]
     (gdb)

The '-data-evaluate-expression' Command
---------------------------------------

Synopsis
........

      -data-evaluate-expression EXPR

   Evaluate EXPR as an expression.  The expression could contain an
inferior function call.  The function call will execute synchronously.
If the expression contains spaces, it must be enclosed in double quotes.

GDB Command
...........

The corresponding GDB commands are 'print', 'output', and 'call'.  In
'gdbtk' only, there's a corresponding 'gdb_eval' command.

Example
.......

In the following example, the numbers that precede the commands are the
"tokens" described in *note GDB/MI Command Syntax: GDB/MI Command
Syntax.  Notice how GDB/MI returns the same tokens in its output.

     211-data-evaluate-expression A
     211^done,value="1"
     (gdb)
     311-data-evaluate-expression &A
     311^done,value="0xefffeb7c"
     (gdb)
     411-data-evaluate-expression A+3
     411^done,value="4"
     (gdb)
     511-data-evaluate-expression "A + 3"
     511^done,value="4"
     (gdb)

The '-data-list-changed-registers' Command
------------------------------------------

Synopsis
........

      -data-list-changed-registers

   Display a list of the registers that have changed.

GDB Command
...........

GDB doesn't have a direct analog for this command; 'gdbtk' has the
corresponding command 'gdb_changed_register_list'.

Example
.......

On a PPC MBX board:

     (gdb)
     -exec-continue
     ^running

     (gdb)
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame={
     func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c",
     line="5",arch="powerpc"}
     (gdb)
     -data-list-changed-registers
     ^done,changed-registers=["0","1","2","4","5","6","7","8","9",
     "10","11","13","14","15","16","17","18","19","20","21","22","23",
     "24","25","26","27","28","30","31","64","65","66","67","69"]
     (gdb)

The '-data-list-register-names' Command
---------------------------------------

Synopsis
........

      -data-list-register-names [ ( REGNO )+ ]

   Show a list of register names for the current target.  If no
arguments are given, it shows a list of the names of all the registers.
If integer numbers are given as arguments, it will print a list of the
names of the registers corresponding to the arguments.  To ensure
consistency between a register name and its number, the output list may
include empty register names.

GDB Command
...........

GDB does not have a command which corresponds to
'-data-list-register-names'.  In 'gdbtk' there is a corresponding
command 'gdb_regnames'.

Example
.......

For the PPC MBX board:
     (gdb)
     -data-list-register-names
     ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7",
     "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18",
     "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29",
     "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9",
     "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20",
     "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31",
     "", "pc","ps","cr","lr","ctr","xer"]
     (gdb)
     -data-list-register-names 1 2 3
     ^done,register-names=["r1","r2","r3"]
     (gdb)

The '-data-list-register-values' Command
----------------------------------------

Synopsis
........

      -data-list-register-values
         [ --skip-unavailable ] FMT [ ( REGNO )*]

   Display the registers' contents.  The format according to which the
registers' contents are to be returned is given by FMT, followed by an
optional list of numbers specifying the registers to display.  A missing
list of numbers indicates that the contents of all the registers must be
returned.  The '--skip-unavailable' option indicates that only the
available registers are to be returned.

   Allowed formats for FMT are:

'x'
     Hexadecimal
'o'
     Octal
't'
     Binary
'd'
     Decimal
'r'
     Raw
'N'
     Natural

GDB Command
...........

The corresponding GDB commands are 'info reg', 'info all-reg', and (in
'gdbtk') 'gdb_fetch_registers'.

Example
.......

For a PPC MBX board (note: line breaks are for readability only, they
don't appear in the actual output):

     (gdb)
     -data-list-register-values r 64 65
     ^done,register-values=[{number="64",value="0xfe00a300"},
     {number="65",value="0x00029002"}]
     (gdb)
     -data-list-register-values x
     ^done,register-values=[{number="0",value="0xfe0043c8"},
     {number="1",value="0x3fff88"},{number="2",value="0xfffffffe"},
     {number="3",value="0x0"},{number="4",value="0xa"},
     {number="5",value="0x3fff68"},{number="6",value="0x3fff58"},
     {number="7",value="0xfe011e98"},{number="8",value="0x2"},
     {number="9",value="0xfa202820"},{number="10",value="0xfa202808"},
     {number="11",value="0x1"},{number="12",value="0x0"},
     {number="13",value="0x4544"},{number="14",value="0xffdfffff"},
     {number="15",value="0xffffffff"},{number="16",value="0xfffffeff"},
     {number="17",value="0xefffffed"},{number="18",value="0xfffffffe"},
     {number="19",value="0xffffffff"},{number="20",value="0xffffffff"},
     {number="21",value="0xffffffff"},{number="22",value="0xfffffff7"},
     {number="23",value="0xffffffff"},{number="24",value="0xffffffff"},
     {number="25",value="0xffffffff"},{number="26",value="0xfffffffb"},
     {number="27",value="0xffffffff"},{number="28",value="0xf7bfffff"},
     {number="29",value="0x0"},{number="30",value="0xfe010000"},
     {number="31",value="0x0"},{number="32",value="0x0"},
     {number="33",value="0x0"},{number="34",value="0x0"},
     {number="35",value="0x0"},{number="36",value="0x0"},
     {number="37",value="0x0"},{number="38",value="0x0"},
     {number="39",value="0x0"},{number="40",value="0x0"},
     {number="41",value="0x0"},{number="42",value="0x0"},
     {number="43",value="0x0"},{number="44",value="0x0"},
     {number="45",value="0x0"},{number="46",value="0x0"},
     {number="47",value="0x0"},{number="48",value="0x0"},
     {number="49",value="0x0"},{number="50",value="0x0"},
     {number="51",value="0x0"},{number="52",value="0x0"},
     {number="53",value="0x0"},{number="54",value="0x0"},
     {number="55",value="0x0"},{number="56",value="0x0"},
     {number="57",value="0x0"},{number="58",value="0x0"},
     {number="59",value="0x0"},{number="60",value="0x0"},
     {number="61",value="0x0"},{number="62",value="0x0"},
     {number="63",value="0x0"},{number="64",value="0xfe00a300"},
     {number="65",value="0x29002"},{number="66",value="0x202f04b5"},
     {number="67",value="0xfe0043b0"},{number="68",value="0xfe00b3e4"},
     {number="69",value="0x20002b03"}]
     (gdb)

The '-data-read-memory' Command
-------------------------------

This command is deprecated, use '-data-read-memory-bytes' instead.

Synopsis
........

      -data-read-memory [ -o BYTE-OFFSET ]
        ADDRESS WORD-FORMAT WORD-SIZE
        NR-ROWS NR-COLS [ ASCHAR ]

where:

'ADDRESS'
     An expression specifying the address of the first memory word to be
     read.  Complex expressions containing embedded white space should
     be quoted using the C convention.

'WORD-FORMAT'
     The format to be used to print the memory words.  The notation is
     the same as for GDB's 'print' command (*note Output Formats: Output
     Formats.).

'WORD-SIZE'
     The size of each memory word in bytes.

'NR-ROWS'
     The number of rows in the output table.

'NR-COLS'
     The number of columns in the output table.

'ASCHAR'
     If present, indicates that each row should include an ASCII dump.
     The value of ASCHAR is used as a padding character when a byte is
     not a member of the printable ASCII character set (printable ASCII
     characters are those whose code is between 32 and 126,
     inclusively).

'BYTE-OFFSET'
     An offset to add to the ADDRESS before fetching memory.

   This command displays memory contents as a table of NR-ROWS by
NR-COLS words, each word being WORD-SIZE bytes.  In total, 'NR-ROWS *
NR-COLS * WORD-SIZE' bytes are read (returned as 'total-bytes').  Should
less than the requested number of bytes be returned by the target, the
missing words are identified using 'N/A'.  The number of bytes read from
the target is returned in 'nr-bytes' and the starting address used to
read memory in 'addr'.

   The address of the next/previous row or page is available in
'next-row' and 'prev-row', 'next-page' and 'prev-page'.

GDB Command
...........

The corresponding GDB command is 'x'.  'gdbtk' has 'gdb_get_mem' memory
read command.

Example
.......

Read six bytes of memory starting at 'bytes+6' but then offset by '-6'
bytes.  Format as three rows of two columns.  One byte per word.
Display each word in hex.

     (gdb)
     9-data-read-memory -o -6 -- bytes+6 x 1 3 2
     9^done,addr="0x00001390",nr-bytes="6",total-bytes="6",
     next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396",
     prev-page="0x0000138a",memory=[
     {addr="0x00001390",data=["0x00","0x01"]},
     {addr="0x00001392",data=["0x02","0x03"]},
     {addr="0x00001394",data=["0x04","0x05"]}]
     (gdb)

   Read two bytes of memory starting at address 'shorts + 64' and
display as a single word formatted in decimal.

     (gdb)
     5-data-read-memory shorts+64 d 2 1 1
     5^done,addr="0x00001510",nr-bytes="2",total-bytes="2",
     next-row="0x00001512",prev-row="0x0000150e",
     next-page="0x00001512",prev-page="0x0000150e",memory=[
     {addr="0x00001510",data=["128"]}]
     (gdb)

   Read thirty two bytes of memory starting at 'bytes+16' and format as
eight rows of four columns.  Include a string encoding with 'x' used as
the non-printable character.

     (gdb)
     4-data-read-memory bytes+16 x 1 8 4 x
     4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32",
     next-row="0x000013c0",prev-row="0x0000139c",
     next-page="0x000013c0",prev-page="0x00001380",memory=[
     {addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"},
     {addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"},
     {addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"},
     {addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"},
     {addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"},
     {addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"},
     {addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"},
     {addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"}]
     (gdb)

The '-data-read-memory-bytes' Command
-------------------------------------

Synopsis
........

      -data-read-memory-bytes [ -o OFFSET ]
        ADDRESS COUNT

where:

'ADDRESS'
     An expression specifying the address of the first addressable
     memory unit to be read.  Complex expressions containing embedded
     white space should be quoted using the C convention.

'COUNT'
     The number of addressable memory units to read.  This should be an
     integer literal.

'OFFSET'
     The offset relative to ADDRESS at which to start reading.  This
     should be an integer literal.  This option is provided so that a
     frontend is not required to first evaluate address and then perform
     address arithmetics itself.

   This command attempts to read all accessible memory regions in the
specified range.  First, all regions marked as unreadable in the memory
map (if one is defined) will be skipped.  *Note Memory Region
Attributes::.  Second, GDB will attempt to read the remaining regions.
For each one, if reading full region results in an errors, GDB will try
to read a subset of the region.

   In general, every single memory unit in the region may be readable or
not, and the only way to read every readable unit is to try a read at
every address, which is not practical.  Therefore, GDB will attempt to
read all accessible memory units at either beginning or the end of the
region, using a binary division scheme.  This heuristic works well for
reading across a memory map boundary.  Note that if a region has a
readable range that is neither at the beginning or the end, GDB will not
read it.

   The result record (*note GDB/MI Result Records::) that is output of
the command includes a field named 'memory' whose content is a list of
tuples.  Each tuple represent a successfully read memory block and has
the following fields:

'begin'
     The start address of the memory block, as hexadecimal literal.

'end'
     The end address of the memory block, as hexadecimal literal.

'offset'
     The offset of the memory block, as hexadecimal literal, relative to
     the start address passed to '-data-read-memory-bytes'.

'contents'
     The contents of the memory block, in hex.

GDB Command
...........

The corresponding GDB command is 'x'.

Example
.......

     (gdb)
     -data-read-memory-bytes &a 10
     ^done,memory=[{begin="0xbffff154",offset="0x00000000",
                   end="0xbffff15e",
                   contents="01000000020000000300"}]
     (gdb)

The '-data-write-memory-bytes' Command
--------------------------------------

Synopsis
........

      -data-write-memory-bytes ADDRESS CONTENTS
      -data-write-memory-bytes ADDRESS CONTENTS [COUNT]

where:

'ADDRESS'
     An expression specifying the address of the first addressable
     memory unit to be written.  Complex expressions containing embedded
     white space should be quoted using the C convention.

'CONTENTS'
     The hex-encoded data to write.  It is an error if CONTENTS does not
     represent an integral number of addressable memory units.

'COUNT'
     Optional argument indicating the number of addressable memory units
     to be written.  If COUNT is greater than CONTENTS' length, GDB will
     repeatedly write CONTENTS until it fills COUNT memory units.

GDB Command
...........

There's no corresponding GDB command.

Example
.......

     (gdb)
     -data-write-memory-bytes &a "aabbccdd"
     ^done
     (gdb)

     (gdb)
     -data-write-memory-bytes &a "aabbccdd" 16e
     ^done
     (gdb)


File: gdb.info,  Node: GDB/MI Tracepoint Commands,  Next: GDB/MI Symbol Query,  Prev: GDB/MI Data Manipulation,  Up: GDB/MI

27.17 GDB/MI Tracepoint Commands
================================

The commands defined in this section implement MI support for
tracepoints.  For detailed introduction, see *note Tracepoints::.

The '-trace-find' Command
-------------------------

Synopsis
........

      -trace-find MODE [PARAMETERS...]

   Find a trace frame using criteria defined by MODE and PARAMETERS.
The following table lists permissible modes and their parameters.  For
details of operation, see *note tfind::.

'none'
     No parameters are required.  Stops examining trace frames.

'frame-number'
     An integer is required as parameter.  Selects tracepoint frame with
     that index.

'tracepoint-number'
     An integer is required as parameter.  Finds next trace frame that
     corresponds to tracepoint with the specified number.

'pc'
     An address is required as parameter.  Finds next trace frame that
     corresponds to any tracepoint at the specified address.

'pc-inside-range'
     Two addresses are required as parameters.  Finds next trace frame
     that corresponds to a tracepoint at an address inside the specified
     range.  Both bounds are considered to be inside the range.

'pc-outside-range'
     Two addresses are required as parameters.  Finds next trace frame
     that corresponds to a tracepoint at an address outside the
     specified range.  Both bounds are considered to be inside the
     range.

'line'
     Location specification is required as parameter.  *Note Location
     Specifications::.  Finds next trace frame that corresponds to a
     tracepoint at the specified location.

   If 'none' was passed as MODE, the response does not have fields.
Otherwise, the response may have the following fields:

'found'
     This field has either '0' or '1' as the value, depending on whether
     a matching tracepoint was found.

'traceframe'
     The index of the found traceframe.  This field is present iff the
     'found' field has value of '1'.

'tracepoint'
     The index of the found tracepoint.  This field is present iff the
     'found' field has value of '1'.

'frame'
     The information about the frame corresponding to the found trace
     frame.  This field is present only if a trace frame was found.
     *Note GDB/MI Frame Information::, for description of this field.

GDB Command
...........

The corresponding GDB command is 'tfind'.

-trace-define-variable
----------------------

Synopsis
........

      -trace-define-variable NAME [ VALUE ]

   Create trace variable NAME if it does not exist.  If VALUE is
specified, sets the initial value of the specified trace variable to
that value.  Note that the NAME should start with the '$' character.

GDB Command
...........

The corresponding GDB command is 'tvariable'.

The '-trace-frame-collected' Command
------------------------------------

Synopsis
........

      -trace-frame-collected
         [--var-print-values VAR_PVAL]
         [--comp-print-values COMP_PVAL]
         [--registers-format REGFORMAT]
         [--memory-contents]

   This command returns the set of collected objects, register names,
trace state variable names, memory ranges and computed expressions that
have been collected at a particular trace frame.  The optional
parameters to the command affect the output format in different ways.
See the output description table below for more details.

   The reported names can be used in the normal manner to create varobjs
and inspect the objects themselves.  The items returned by this command
are categorized so that it is clear which is a variable, which is a
register, which is a trace state variable, which is a memory range and
which is a computed expression.

   For instance, if the actions were
     collect myVar, myArray[myIndex], myObj.field, myPtr->field, myCount + 2
     collect *(int*)0xaf02bef0@40

the object collected in its entirety would be 'myVar'.  The object
'myArray' would be partially collected, because only the element at
index 'myIndex' would be collected.  The remaining objects would be
computed expressions.

   An example output would be:

     (gdb)
     -trace-frame-collected
     ^done,
       explicit-variables=[{name="myVar",value="1"}],
       computed-expressions=[{name="myArray[myIndex]",value="0"},
                             {name="myObj.field",value="0"},
                             {name="myPtr->field",value="1"},
                             {name="myCount + 2",value="3"},
                             {name="$tvar1 + 1",value="43970027"}],
       registers=[{number="0",value="0x7fe2c6e79ec8"},
                  {number="1",value="0x0"},
                  {number="2",value="0x4"},
                  ...
                  {number="125",value="0x0"}],
       tvars=[{name="$tvar1",current="43970026"}],
       memory=[{address="0x0000000000602264",length="4"},
               {address="0x0000000000615bc0",length="4"}]
     (gdb)

   Where:

'explicit-variables'
     The set of objects that have been collected in their entirety (as
     opposed to collecting just a few elements of an array or a few
     struct members).  For each object, its name and value are printed.
     The '--var-print-values' option affects how or whether the value
     field is output.  If VAR_PVAL is 0, then print only the names; if
     it is 1, print also their values; and if it is 2, print the name,
     type and value for simple data types, and the name and type for
     arrays, structures and unions.

'computed-expressions'
     The set of computed expressions that have been collected at the
     current trace frame.  The '--comp-print-values' option affects this
     set like the '--var-print-values' option affects the
     'explicit-variables' set.  See above.

'registers'
     The registers that have been collected at the current trace frame.
     For each register collected, the name and current value are
     returned.  The value is formatted according to the
     '--registers-format' option.  See the '-data-list-register-values'
     command for a list of the allowed formats.  The default is 'x'.

'tvars'
     The trace state variables that have been collected at the current
     trace frame.  For each trace state variable collected, the name and
     current value are returned.

'memory'
     The set of memory ranges that have been collected at the current
     trace frame.  Its content is a list of tuples.  Each tuple
     represents a collected memory range and has the following fields:

     'address'
          The start address of the memory range, as hexadecimal literal.

     'length'
          The length of the memory range, as decimal literal.

     'contents'
          The contents of the memory block, in hex.  This field is only
          present if the '--memory-contents' option is specified.

GDB Command
...........

There is no corresponding GDB command.

Example
.......

-trace-list-variables
---------------------

Synopsis
........

      -trace-list-variables

   Return a table of all defined trace variables.  Each element of the
table has the following fields:

'name'
     The name of the trace variable.  This field is always present.

'initial'
     The initial value.  This is a 64-bit signed integer.  This field is
     always present.

'current'
     The value the trace variable has at the moment.  This is a 64-bit
     signed integer.  This field is absent iff current value is not
     defined, for example if the trace was never run, or is presently
     running.

GDB Command
...........

The corresponding GDB command is 'tvariables'.

Example
.......

     (gdb)
     -trace-list-variables
     ^done,trace-variables={nr_rows="1",nr_cols="3",
     hdr=[{width="15",alignment="-1",col_name="name",colhdr="Name"},
          {width="11",alignment="-1",col_name="initial",colhdr="Initial"},
          {width="11",alignment="-1",col_name="current",colhdr="Current"}],
     body=[variable={name="$trace_timestamp",initial="0"}
           variable={name="$foo",initial="10",current="15"}]}
     (gdb)

-trace-save
-----------

Synopsis
........

      -trace-save [ -r ] [ -ctf ] FILENAME

   Saves the collected trace data to FILENAME.  Without the '-r' option,
the data is downloaded from the target and saved in a local file.  With
the '-r' option the target is asked to perform the save.

   By default, this command will save the trace in the tfile format.
You can supply the optional '-ctf' argument to save it the CTF format.
See *note Trace Files:: for more information about CTF.

GDB Command
...........

The corresponding GDB command is 'tsave'.

-trace-start
------------

Synopsis
........

      -trace-start

   Starts a tracing experiment.  The result of this command does not
have any fields.

GDB Command
...........

The corresponding GDB command is 'tstart'.

-trace-status
-------------

Synopsis
........

      -trace-status

   Obtains the status of a tracing experiment.  The result may include
the following fields:

'supported'
     May have a value of either '0', when no tracing operations are
     supported, '1', when all tracing operations are supported, or
     'file' when examining trace file.  In the latter case, examining of
     trace frame is possible but new tracing experiement cannot be
     started.  This field is always present.

'running'
     May have a value of either '0' or '1' depending on whether tracing
     experiement is in progress on target.  This field is present if
     'supported' field is not '0'.

'stop-reason'
     Report the reason why the tracing was stopped last time.  This
     field may be absent iff tracing was never stopped on target yet.
     The value of 'request' means the tracing was stopped as result of
     the '-trace-stop' command.  The value of 'overflow' means the
     tracing buffer is full.  The value of 'disconnection' means tracing
     was automatically stopped when GDB has disconnected.  The value of
     'passcount' means tracing was stopped when a tracepoint was passed
     a maximal number of times for that tracepoint.  This field is
     present if 'supported' field is not '0'.

'stopping-tracepoint'
     The number of tracepoint whose passcount as exceeded.  This field
     is present iff the 'stop-reason' field has the value of
     'passcount'.

'frames'
'frames-created'
     The 'frames' field is a count of the total number of trace frames
     in the trace buffer, while 'frames-created' is the total created
     during the run, including ones that were discarded, such as when a
     circular trace buffer filled up.  Both fields are optional.

'buffer-size'
'buffer-free'
     These fields tell the current size of the tracing buffer and the
     remaining space.  These fields are optional.

'circular'
     The value of the circular trace buffer flag.  '1' means that the
     trace buffer is circular and old trace frames will be discarded if
     necessary to make room, '0' means that the trace buffer is linear
     and may fill up.

'disconnected'
     The value of the disconnected tracing flag.  '1' means that tracing
     will continue after GDB disconnects, '0' means that the trace run
     will stop.

'trace-file'
     The filename of the trace file being examined.  This field is
     optional, and only present when examining a trace file.

GDB Command
...........

The corresponding GDB command is 'tstatus'.

-trace-stop
-----------

Synopsis
........

      -trace-stop

   Stops a tracing experiment.  The result of this command has the same
fields as '-trace-status', except that the 'supported' and 'running'
fields are not output.

GDB Command
...........

The corresponding GDB command is 'tstop'.


File: gdb.info,  Node: GDB/MI Symbol Query,  Next: GDB/MI File Commands,  Prev: GDB/MI Tracepoint Commands,  Up: GDB/MI

27.18 GDB/MI Symbol Query Commands
==================================

The '-symbol-info-functions' Command
------------------------------------

Synopsis
........

      -symbol-info-functions [--include-nondebug]
                             [--type TYPE_REGEXP]
                             [--name NAME_REGEXP]
                             [--max-results LIMIT]

Return a list containing the names and types for all global functions
taken from the debug information.  The functions are grouped by source
file, and shown with the line number on which each function is defined.

   The '--include-nondebug' option causes the output to include code
symbols from the symbol table.

   The options '--type' and '--name' allow the symbols returned to be
filtered based on either the name of the function, or the type signature
of the function.

   The option '--max-results' restricts the command to return no more
than LIMIT results.  If exactly LIMIT results are returned then there
might be additional results available if a higher limit is used.

GDB Command
...........

The corresponding GDB command is 'info functions'.

Example
.......

     (gdb)
     -symbol-info-functions
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="36", name="f4", type="void (int *)",
                     description="void f4(int *);"},
                    {line="42", name="main", type="int ()",
                     description="int main();"},
                    {line="30", name="f1", type="my_int_t (int, int)",
                     description="static my_int_t f1(int, int);"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="33", name="f2", type="float (another_float_t)",
                     description="float f2(another_float_t);"},
                    {line="39", name="f3", type="int (another_int_t)",
                     description="int f3(another_int_t);"},
                    {line="27", name="f1", type="another_float_t (int)",
                     description="static another_float_t f1(int);"}]}]}
     (gdb)
     -symbol-info-functions --name f1
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="30", name="f1", type="my_int_t (int, int)",
                     description="static my_int_t f1(int, int);"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="27", name="f1", type="another_float_t (int)",
                     description="static another_float_t f1(int);"}]}]}
     (gdb)
     -symbol-info-functions --type void
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="36", name="f4", type="void (int *)",
                     description="void f4(int *);"}]}]}
     (gdb)
     -symbol-info-functions --include-nondebug
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="36", name="f4", type="void (int *)",
                     description="void f4(int *);"},
                    {line="42", name="main", type="int ()",
                     description="int main();"},
                    {line="30", name="f1", type="my_int_t (int, int)",
                     description="static my_int_t f1(int, int);"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="33", name="f2", type="float (another_float_t)",
                     description="float f2(another_float_t);"},
                    {line="39", name="f3", type="int (another_int_t)",
                     description="int f3(another_int_t);"},
                    {line="27", name="f1", type="another_float_t (int)",
                     description="static another_float_t f1(int);"}]}],
        nondebug=
         [{address="0x0000000000400398",name="_init"},
          {address="0x00000000004003b0",name="_start"},
           ...
         ]}

The '-symbol-info-module-functions' Command
-------------------------------------------

Synopsis
........

      -symbol-info-module-functions [--module MODULE_REGEXP]
                                    [--name NAME_REGEXP]
                                    [--type TYPE_REGEXP]

Return a list containing the names of all known functions within all
know Fortran modules.  The functions are grouped by source file and
containing module, and shown with the line number on which each function
is defined.

   The option '--module' only returns results for modules matching
MODULE_REGEXP.  The option '--name' only returns functions whose name
matches NAME_REGEXP, and '--type' only returns functions whose type
matches TYPE_REGEXP.

GDB Command
...........

The corresponding GDB command is 'info module functions'.

Example
.......

     (gdb)
     -symbol-info-module-functions
     ^done,symbols=
       [{module="mod1",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 symbols=[{line="21",name="mod1::check_all",type="void (void)",
                           description="void mod1::check_all(void);"}]}]},
         {module="mod2",
          files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                  fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                  symbols=[{line="30",name="mod2::check_var_i",type="void (void)",
                            description="void mod2::check_var_i(void);"}]}]},
         {module="mod3",
          files=[{filename="/projec/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  fullname="/projec/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  symbols=[{line="21",name="mod3::check_all",type="void (void)",
                            description="void mod3::check_all(void);"},
                           {line="27",name="mod3::check_mod2",type="void (void)",
                            description="void mod3::check_mod2(void);"}]}]},
         {module="modmany",
          files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  symbols=[{line="35",name="modmany::check_some",type="void (void)",
                            description="void modmany::check_some(void);"}]}]},
         {module="moduse",
          files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                  symbols=[{line="44",name="moduse::check_all",type="void (void)",
                            description="void moduse::check_all(void);"},
                           {line="49",name="moduse::check_var_x",type="void (void)",
                            description="void moduse::check_var_x(void);"}]}]}]

The '-symbol-info-module-variables' Command
-------------------------------------------

Synopsis
........

      -symbol-info-module-variables [--module MODULE_REGEXP]
                                    [--name NAME_REGEXP]
                                    [--type TYPE_REGEXP]

Return a list containing the names of all known variables within all
know Fortran modules.  The variables are grouped by source file and
containing module, and shown with the line number on which each variable
is defined.

   The option '--module' only returns results for modules matching
MODULE_REGEXP.  The option '--name' only returns variables whose name
matches NAME_REGEXP, and '--type' only returns variables whose type
matches TYPE_REGEXP.

GDB Command
...........

The corresponding GDB command is 'info module variables'.

Example
.......

     (gdb)
     -symbol-info-module-variables
     ^done,symbols=
       [{module="mod1",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 symbols=[{line="18",name="mod1::var_const",type="integer(kind=4)",
                           description="integer(kind=4) mod1::var_const;"},
                          {line="17",name="mod1::var_i",type="integer(kind=4)",
                           description="integer(kind=4) mod1::var_i;"}]}]},
        {module="mod2",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
                 symbols=[{line="28",name="mod2::var_i",type="integer(kind=4)",
                           description="integer(kind=4) mod2::var_i;"}]}]},
        {module="mod3",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 symbols=[{line="18",name="mod3::mod1",type="integer(kind=4)",
                           description="integer(kind=4) mod3::mod1;"},
                          {line="17",name="mod3::mod2",type="integer(kind=4)",
                           description="integer(kind=4) mod3::mod2;"},
                          {line="19",name="mod3::var_i",type="integer(kind=4)",
                           description="integer(kind=4) mod3::var_i;"}]}]},
        {module="modmany",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 symbols=[{line="33",name="modmany::var_a",type="integer(kind=4)",
                           description="integer(kind=4) modmany::var_a;"},
                          {line="33",name="modmany::var_b",type="integer(kind=4)",
                           description="integer(kind=4) modmany::var_b;"},
                          {line="33",name="modmany::var_c",type="integer(kind=4)",
                           description="integer(kind=4) modmany::var_c;"},
                          {line="33",name="modmany::var_i",type="integer(kind=4)",
                           description="integer(kind=4) modmany::var_i;"}]}]},
        {module="moduse",
         files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
                 symbols=[{line="42",name="moduse::var_x",type="integer(kind=4)",
                           description="integer(kind=4) moduse::var_x;"},
                          {line="42",name="moduse::var_y",type="integer(kind=4)",
                           description="integer(kind=4) moduse::var_y;"}]}]}]

The '-symbol-info-modules' Command
----------------------------------

Synopsis
........

      -symbol-info-modules [--name NAME_REGEXP]
                           [--max-results LIMIT]


Return a list containing the names of all known Fortran modules.  The
modules are grouped by source file, and shown with the line number on
which each modules is defined.

   The option '--name' allows the modules returned to be filtered based
the name of the module.

   The option '--max-results' restricts the command to return no more
than LIMIT results.  If exactly LIMIT results are returned then there
might be additional results available if a higher limit is used.

GDB Command
...........

The corresponding GDB command is 'info modules'.

Example
.......

     (gdb)
     -symbol-info-modules
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
           fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
           symbols=[{line="16",name="mod1"},
                    {line="22",name="mod2"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
           fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
           symbols=[{line="16",name="mod3"},
                    {line="22",name="modmany"},
                    {line="26",name="moduse"}]}]}
     (gdb)
     -symbol-info-modules --name mod[123]
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
           fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90",
           symbols=[{line="16",name="mod1"},
                    {line="22",name="mod2"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
           fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90",
           symbols=[{line="16",name="mod3"}]}]}

The '-symbol-info-types' Command
--------------------------------

Synopsis
........

      -symbol-info-types [--name NAME_REGEXP]
                         [--max-results LIMIT]


Return a list of all defined types.  The types are grouped by source
file, and shown with the line number on which each user defined type is
defined.  Some base types are not defined in the source code but are
added to the debug information by the compiler, for example 'int',
'float', etc.; these types do not have an associated line number.

   The option '--name' allows the list of types returned to be filtered
by name.

   The option '--max-results' restricts the command to return no more
than LIMIT results.  If exactly LIMIT results are returned then there
might be additional results available if a higher limit is used.

GDB Command
...........

The corresponding GDB command is 'info types'.

Example
.......

     (gdb)
     -symbol-info-types
     ^done,symbols=
       {debug=
          [{filename="gdb.mi/mi-sym-info-1.c",
            fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
            symbols=[{name="float"},
                     {name="int"},
                     {line="27",name="typedef int my_int_t;"}]},
           {filename="gdb.mi/mi-sym-info-2.c",
            fullname="/project/gdb.mi/mi-sym-info-2.c",
            symbols=[{line="24",name="typedef float another_float_t;"},
                     {line="23",name="typedef int another_int_t;"},
                     {name="float"},
                     {name="int"}]}]}
     (gdb)
     -symbol-info-types --name _int_
     ^done,symbols=
       {debug=
          [{filename="gdb.mi/mi-sym-info-1.c",
            fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
            symbols=[{line="27",name="typedef int my_int_t;"}]},
           {filename="gdb.mi/mi-sym-info-2.c",
            fullname="/project/gdb.mi/mi-sym-info-2.c",
            symbols=[{line="23",name="typedef int another_int_t;"}]}]}

The '-symbol-info-variables' Command
------------------------------------

Synopsis
........

      -symbol-info-variables [--include-nondebug]
                             [--type TYPE_REGEXP]
                             [--name NAME_REGEXP]
                             [--max-results LIMIT]


Return a list containing the names and types for all global variables
taken from the debug information.  The variables are grouped by source
file, and shown with the line number on which each variable is defined.

   The '--include-nondebug' option causes the output to include data
symbols from the symbol table.

   The options '--type' and '--name' allow the symbols returned to be
filtered based on either the name of the variable, or the type of the
variable.

   The option '--max-results' restricts the command to return no more
than LIMIT results.  If exactly LIMIT results are returned then there
might be additional results available if a higher limit is used.

GDB Command
...........

The corresponding GDB command is 'info variables'.

Example
.......

     (gdb)
     -symbol-info-variables
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="25",name="global_f1",type="float",
                     description="static float global_f1;"},
                    {line="24",name="global_i1",type="int",
                     description="static int global_i1;"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="21",name="global_f2",type="int",
                     description="int global_f2;"},
                    {line="20",name="global_i2",type="int",
                     description="int global_i2;"},
                    {line="19",name="global_f1",type="float",
                     description="static float global_f1;"},
                    {line="18",name="global_i1",type="int",
                     description="static int global_i1;"}]}]}
     (gdb)
     -symbol-info-variables --name f1
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="25",name="global_f1",type="float",
                     description="static float global_f1;"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="19",name="global_f1",type="float",
                     description="static float global_f1;"}]}]}
     (gdb)
     -symbol-info-variables --type float
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="25",name="global_f1",type="float",
                     description="static float global_f1;"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="19",name="global_f1",type="float",
                     description="static float global_f1;"}]}]}
     (gdb)
     -symbol-info-variables --include-nondebug
     ^done,symbols=
       {debug=
         [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c",
           symbols=[{line="25",name="global_f1",type="float",
                     description="static float global_f1;"},
                    {line="24",name="global_i1",type="int",
                     description="static int global_i1;"}]},
          {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c",
           symbols=[{line="21",name="global_f2",type="int",
                     description="int global_f2;"},
                    {line="20",name="global_i2",type="int",
                     description="int global_i2;"},
                    {line="19",name="global_f1",type="float",
                     description="static float global_f1;"},
                    {line="18",name="global_i1",type="int",
                     description="static int global_i1;"}]}],
        nondebug=
         [{address="0x00000000004005d0",name="_IO_stdin_used"},
          {address="0x00000000004005d8",name="__dso_handle"}
           ...
         ]}

The '-symbol-list-lines' Command
--------------------------------

Synopsis
........

      -symbol-list-lines FILENAME

   Print the list of lines that contain code and their associated
program addresses for the given source filename.  The entries are sorted
in ascending PC order.

GDB Command
...........

There is no corresponding GDB command.

Example
.......

     (gdb)
     -symbol-list-lines basics.c
     ^done,lines=[{pc="0x08048554",line="7"},{pc="0x0804855a",line="8"}]
     (gdb)


File: gdb.info,  Node: GDB/MI File Commands,  Next: GDB/MI Target Manipulation,  Prev: GDB/MI Symbol Query,  Up: GDB/MI

27.19 GDB/MI File Commands
==========================

This section describes the GDB/MI commands to specify executable file
names and to read in and obtain symbol table information.

The '-file-exec-and-symbols' Command
------------------------------------

Synopsis
........

      -file-exec-and-symbols FILE

   Specify the executable file to be debugged.  This file is the one
from which the symbol table is also read.  If no file is specified, the
command clears the executable and symbol information.  If breakpoints
are set when using this command with no arguments, GDB will produce
error messages.  Otherwise, no output is produced, except a completion
notification.

GDB Command
...........

The corresponding GDB command is 'file'.

Example
.......

     (gdb)
     -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
     ^done
     (gdb)

The '-file-exec-file' Command
-----------------------------

Synopsis
........

      -file-exec-file FILE

   Specify the executable file to be debugged.  Unlike
'-file-exec-and-symbols', the symbol table is _not_ read from this file.
If used without argument, GDB clears the information about the
executable file.  No output is produced, except a completion
notification.

GDB Command
...........

The corresponding GDB command is 'exec-file'.

Example
.......

     (gdb)
     -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
     ^done
     (gdb)

The '-file-list-exec-source-file' Command
-----------------------------------------

Synopsis
........

      -file-list-exec-source-file

   List the line number, the current source file, and the absolute path
to the current source file for the current executable.  The macro
information field has a value of '1' or '0' depending on whether or not
the file includes preprocessor macro information.

GDB Command
...........

The GDB equivalent is 'info source'

Example
.......

     (gdb)
     123-file-list-exec-source-file
     123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1"
     (gdb)

The '-file-list-exec-source-files' Command
------------------------------------------

Synopsis
........

      -file-list-exec-source-files [ --GROUP-BY-OBJFILE ]
                                   [ --DIRNAME | --BASENAME ]
                                   [ -- ]
                                   [ REGEXP ]

   This command returns information about the source files GDB knows
about, it will output both the filename and fullname (absolute file
name) of a source file, though the fullname can be elided if this
information is not known to GDB.

   With no arguments this command returns a list of source files.  Each
source file is represented by a tuple with the fields; FILE, FULLNAME,
and DEBUG-FULLY-READ.  The FILE is the display name for the file, while
FULLNAME is the absolute name of the file.  The FULLNAME field can be
elided if the absolute name of the source file can't be computed.  The
field DEBUG-FULLY-READ will be a string, either 'true' or 'false'.  When
'true', this indicates the full debug information for the compilation
unit describing this file has been read in.  When 'false', the full
debug information has not yet been read in.  While reading in the full
debug information it is possible that GDB could become aware of
additional source files.

   The optional REGEXP can be used to filter the list of source files
returned.  The REGEXP will be matched against the full source file name.
The matching is case-sensitive, except on operating systems that have
case-insensitive filesystem (e.g., MS-Windows).  '--' can be used before
REGEXP to prevent GDB interpreting REGEXP as a command option (e.g. if
REGEXP starts with '-').

   If '--dirname' is provided, then REGEXP is matched only against the
directory name of each source file.  If '--basename' is provided, then
REGEXP is matched against the basename of each source file.  Only one of
'--dirname' or '--basename' may be given, and if either is given then
REGEXP is required.

   If '--group-by-objfile' is used then the format of the results is
changed.  The results will now be a list of tuples, with each tuple
representing an object file (executable or shared library) loaded into
GDB.  The fields of these tuples are; FILENAME, DEBUG-INFO, and SOURCES.
The FILENAME is the absolute name of the object file, DEBUG-INFO is a
string with one of the following values:

'none'
     This object file has no debug information.
'partially-read'
     This object file has debug information, but it is not fully read in
     yet.  When it is read in later, GDB might become aware of
     additional source files.
'fully-read'
     This object file has debug information, and this information is
     fully read into GDB. The list of source files is complete.

   The SOURCES is a list or tuples, with each tuple describing a single
source file with the same fields as described previously.  The SOURCES
list can be empty for object files that have no debug information.

GDB Command
...........

The GDB equivalent is 'info sources'.  'gdbtk' has an analogous command
'gdb_listfiles'.

Example
.......

     (gdb)
     -file-list-exec-source-files
     ^done,files=[{file="foo.c",fullname="/home/foo.c",debug-fully-read="true"},
                  {file="/home/bar.c",fullname="/home/bar.c",debug-fully-read="true"},
                  {file="gdb_could_not_find_fullpath.c",debug-fully-read="true"}]
     (gdb)
     -file-list-exec-source-files
     ^done,files=[{file="test.c",
                   fullname="/tmp/info-sources/test.c",
                   debug-fully-read="true"},
                  {file="/usr/include/stdc-predef.h",
                   fullname="/usr/include/stdc-predef.h",
                   debug-fully-read="true"},
                  {file="header.h",
                   fullname="/tmp/info-sources/header.h",
                   debug-fully-read="true"},
                  {file="helper.c",
                   fullname="/tmp/info-sources/helper.c",
                   debug-fully-read="true"}]
     (gdb)
     -file-list-exec-source-files -- \\.c
     ^done,files=[{file="test.c",
                   fullname="/tmp/info-sources/test.c",
                   debug-fully-read="true"},
                  {file="helper.c",
                   fullname="/tmp/info-sources/helper.c",
                   debug-fully-read="true"}]
     (gdb)
     -file-list-exec-source-files --group-by-objfile
     ^done,files=[{filename="/tmp/info-sources/test.x",
                   debug-info="fully-read",
                   sources=[{file="test.c",
                             fullname="/tmp/info-sources/test.c",
                             debug-fully-read="true"},
                            {file="/usr/include/stdc-predef.h",
                             fullname="/usr/include/stdc-predef.h",
                             debug-fully-read="true"},
                            {file="header.h",
                             fullname="/tmp/info-sources/header.h",
                             debug-fully-read="true"}]},
                  {filename="/lib64/ld-linux-x86-64.so.2",
                   debug-info="none",
                   sources=[]},
                  {filename="system-supplied DSO at 0x7ffff7fcf000",
                   debug-info="none",
                   sources=[]},
                  {filename="/tmp/info-sources/libhelper.so",
                   debug-info="fully-read",
                   sources=[{file="helper.c",
                             fullname="/tmp/info-sources/helper.c",
                             debug-fully-read="true"},
                            {file="/usr/include/stdc-predef.h",
                             fullname="/usr/include/stdc-predef.h",
                             debug-fully-read="true"},
                            {file="header.h",
                             fullname="/tmp/info-sources/header.h",
                             debug-fully-read="true"}]},
                  {filename="/lib64/libc.so.6",
                   debug-info="none",
                   sources=[]}]

The '-file-list-shared-libraries' Command
-----------------------------------------

Synopsis
........

      -file-list-shared-libraries [ REGEXP ]

   List the shared libraries in the program.  With a regular expression
REGEXP, only those libraries whose names match REGEXP are listed.

GDB Command
...........

The corresponding GDB command is 'info shared'.  The fields have a
similar meaning to the '=library-loaded' notification.  The 'ranges'
field specifies the multiple segments belonging to this library.  Each
range has the following fields:

'from'
     The address defining the inclusive lower bound of the segment.
'to'
     The address defining the exclusive upper bound of the segment.

Example
.......

     (gdb)
     -file-list-exec-source-files
     ^done,shared-libraries=[
     {id="/lib/libfoo.so",target-name="/lib/libfoo.so",host-name="/lib/libfoo.so",symbols-loaded="1",thread-group="i1",ranges=[{from="0x72815989",to="0x728162c0"}]},
     {id="/lib/libbar.so",target-name="/lib/libbar.so",host-name="/lib/libbar.so",symbols-loaded="1",thread-group="i1",ranges=[{from="0x76ee48c0",to="0x76ee9160"}]}]
     (gdb)

The '-file-symbol-file' Command
-------------------------------

Synopsis
........

      -file-symbol-file FILE

   Read symbol table info from the specified FILE argument.  When used
without arguments, clears GDB's symbol table info.  No output is
produced, except for a completion notification.

GDB Command
...........

The corresponding GDB command is 'symbol-file'.

Example
.......

     (gdb)
     -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
     ^done
     (gdb)


File: gdb.info,  Node: GDB/MI Target Manipulation,  Next: GDB/MI File Transfer Commands,  Prev: GDB/MI File Commands,  Up: GDB/MI

27.20 GDB/MI Target Manipulation Commands
=========================================

The '-target-attach' Command
----------------------------

Synopsis
........

      -target-attach PID | GID | FILE

   Attach to a process PID or a file FILE outside of GDB, or a thread
group GID.  If attaching to a thread group, the id previously returned
by '-list-thread-groups --available' must be used.

GDB Command
...........

The corresponding GDB command is 'attach'.

Example
.......

     (gdb)
     -target-attach 34
     =thread-created,id="1"
     *stopped,thread-id="1",frame={addr="0xb7f7e410",func="bar",args=[]}
     ^done
     (gdb)

The '-target-detach' Command
----------------------------

Synopsis
........

      -target-detach [ PID | GID ]

   Detach from the remote target which normally resumes its execution.
If either PID or GID is specified, detaches from either the specified
process, or specified thread group.  There's no output.

GDB Command
...........

The corresponding GDB command is 'detach'.

Example
.......

     (gdb)
     -target-detach
     ^done
     (gdb)

The '-target-disconnect' Command
--------------------------------

Synopsis
........

      -target-disconnect

   Disconnect from the remote target.  There's no output and the target
is generally not resumed.

GDB Command
...........

The corresponding GDB command is 'disconnect'.

Example
.......

     (gdb)
     -target-disconnect
     ^done
     (gdb)

The '-target-download' Command
------------------------------

Synopsis
........

      -target-download

   Loads the executable onto the remote target.  It prints out an update
message every half second, which includes the fields:

'section'
     The name of the section.
'section-sent'
     The size of what has been sent so far for that section.
'section-size'
     The size of the section.
'total-sent'
     The total size of what was sent so far (the current and the
     previous sections).
'total-size'
     The size of the overall executable to download.

Each message is sent as status record (*note GDB/MI Output Syntax:
GDB/MI Output Syntax.).

   In addition, it prints the name and size of the sections, as they are
downloaded.  These messages include the following fields:

'section'
     The name of the section.
'section-size'
     The size of the section.
'total-size'
     The size of the overall executable to download.

At the end, a summary is printed.

GDB Command
...........

The corresponding GDB command is 'load'.

Example
.......

Note: each status message appears on a single line.  Here the messages
have been broken down so that they can fit onto a page.

     (gdb)
     -target-download
     +download,{section=".text",section-size="6668",total-size="9880"}
     +download,{section=".text",section-sent="512",section-size="6668",
     total-sent="512",total-size="9880"}
     +download,{section=".text",section-sent="1024",section-size="6668",
     total-sent="1024",total-size="9880"}
     +download,{section=".text",section-sent="1536",section-size="6668",
     total-sent="1536",total-size="9880"}
     +download,{section=".text",section-sent="2048",section-size="6668",
     total-sent="2048",total-size="9880"}
     +download,{section=".text",section-sent="2560",section-size="6668",
     total-sent="2560",total-size="9880"}
     +download,{section=".text",section-sent="3072",section-size="6668",
     total-sent="3072",total-size="9880"}
     +download,{section=".text",section-sent="3584",section-size="6668",
     total-sent="3584",total-size="9880"}
     +download,{section=".text",section-sent="4096",section-size="6668",
     total-sent="4096",total-size="9880"}
     +download,{section=".text",section-sent="4608",section-size="6668",
     total-sent="4608",total-size="9880"}
     +download,{section=".text",section-sent="5120",section-size="6668",
     total-sent="5120",total-size="9880"}
     +download,{section=".text",section-sent="5632",section-size="6668",
     total-sent="5632",total-size="9880"}
     +download,{section=".text",section-sent="6144",section-size="6668",
     total-sent="6144",total-size="9880"}
     +download,{section=".text",section-sent="6656",section-size="6668",
     total-sent="6656",total-size="9880"}
     +download,{section=".init",section-size="28",total-size="9880"}
     +download,{section=".fini",section-size="28",total-size="9880"}
     +download,{section=".data",section-size="3156",total-size="9880"}
     +download,{section=".data",section-sent="512",section-size="3156",
     total-sent="7236",total-size="9880"}
     +download,{section=".data",section-sent="1024",section-size="3156",
     total-sent="7748",total-size="9880"}
     +download,{section=".data",section-sent="1536",section-size="3156",
     total-sent="8260",total-size="9880"}
     +download,{section=".data",section-sent="2048",section-size="3156",
     total-sent="8772",total-size="9880"}
     +download,{section=".data",section-sent="2560",section-size="3156",
     total-sent="9284",total-size="9880"}
     +download,{section=".data",section-sent="3072",section-size="3156",
     total-sent="9796",total-size="9880"}
     ^done,address="0x10004",load-size="9880",transfer-rate="6586",
     write-rate="429"
     (gdb)

GDB Command
...........

No equivalent.

Example
.......

N.A.

The '-target-flash-erase' Command
---------------------------------

Synopsis
........

      -target-flash-erase

   Erases all known flash memory regions on the target.

   The corresponding GDB command is 'flash-erase'.

   The output is a list of flash regions that have been erased, with
starting addresses and memory region sizes.

     (gdb)
     -target-flash-erase
     ^done,erased-regions={address="0x0",size="0x40000"}
     (gdb)

The '-target-select' Command
----------------------------

Synopsis
........

      -target-select TYPE PARAMETERS ...

   Connect GDB to the remote target.  This command takes two args:

'TYPE'
     The type of target, for instance 'remote', etc.
'PARAMETERS'
     Device names, host names and the like.  *Note Commands for Managing
     Targets: Target Commands, for more details.

   The output is a connection notification, followed by the address at
which the target program is, in the following form:

     ^connected,addr="ADDRESS",func="FUNCTION NAME",
       args=[ARG LIST]

GDB Command
...........

The corresponding GDB command is 'target'.

Example
.......

     (gdb)
     -target-select remote /dev/ttya
     ^connected,addr="0xfe00a300",func="??",args=[]
     (gdb)


File: gdb.info,  Node: GDB/MI File Transfer Commands,  Next: GDB/MI Ada Exceptions Commands,  Prev: GDB/MI Target Manipulation,  Up: GDB/MI

27.21 GDB/MI File Transfer Commands
===================================

The '-target-file-put' Command
------------------------------

Synopsis
........

      -target-file-put HOSTFILE TARGETFILE

   Copy file HOSTFILE from the host system (the machine running GDB) to
TARGETFILE on the target system.

GDB Command
...........

The corresponding GDB command is 'remote put'.

Example
.......

     (gdb)
     -target-file-put localfile remotefile
     ^done
     (gdb)

The '-target-file-get' Command
------------------------------

Synopsis
........

      -target-file-get TARGETFILE HOSTFILE

   Copy file TARGETFILE from the target system to HOSTFILE on the host
system.

GDB Command
...........

The corresponding GDB command is 'remote get'.

Example
.......

     (gdb)
     -target-file-get remotefile localfile
     ^done
     (gdb)

The '-target-file-delete' Command
---------------------------------

Synopsis
........

      -target-file-delete TARGETFILE

   Delete TARGETFILE from the target system.

GDB Command
...........

The corresponding GDB command is 'remote delete'.

Example
.......

     (gdb)
     -target-file-delete remotefile
     ^done
     (gdb)


File: gdb.info,  Node: GDB/MI Ada Exceptions Commands,  Next: GDB/MI Support Commands,  Prev: GDB/MI File Transfer Commands,  Up: GDB/MI

27.22 Ada Exceptions GDB/MI Commands
====================================

The '-info-ada-exceptions' Command
----------------------------------

Synopsis
........

      -info-ada-exceptions [ REGEXP]

   List all Ada exceptions defined within the program being debugged.
With a regular expression REGEXP, only those exceptions whose names
match REGEXP are listed.

GDB Command
...........

The corresponding GDB command is 'info exceptions'.

Result
......

The result is a table of Ada exceptions.  The following columns are
defined for each exception:

'name'
     The name of the exception.

'address'
     The address of the exception.

Example
.......

     -info-ada-exceptions aint
     ^done,ada-exceptions={nr_rows="2",nr_cols="2",
     hdr=[{width="1",alignment="-1",col_name="name",colhdr="Name"},
     {width="1",alignment="-1",col_name="address",colhdr="Address"}],
     body=[{name="constraint_error",address="0x0000000000613da0"},
     {name="const.aint_global_e",address="0x0000000000613b00"}]}

Catching Ada Exceptions
-----------------------

The commands describing how to ask GDB to stop when a program raises an
exception are described at *note Ada Exception GDB/MI Catchpoint
Commands::.


File: gdb.info,  Node: GDB/MI Support Commands,  Next: GDB/MI Miscellaneous Commands,  Prev: GDB/MI Ada Exceptions Commands,  Up: GDB/MI

27.23 GDB/MI Support Commands
=============================

Since new commands and features get regularly added to GDB/MI, some
commands are available to help front-ends query the debugger about
support for these capabilities.  Similarly, it is also possible to query
GDB about target support of certain features.

The '-info-gdb-mi-command' Command
----------------------------------

Synopsis
........

      -info-gdb-mi-command CMD_NAME

   Query support for the GDB/MI command named CMD_NAME.

   Note that the dash ('-') starting all GDB/MI commands is technically
not part of the command name (*note GDB/MI Input Syntax::), and thus
should be omitted in CMD_NAME.  However, for ease of use, this command
also accepts the form with the leading dash.

GDB Command
...........

There is no corresponding GDB command.

Result
......

The result is a tuple.  There is currently only one field:

'exists'
     This field is equal to '"true"' if the GDB/MI command exists,
     '"false"' otherwise.

Example
.......

Here is an example where the GDB/MI command does not exist:

     -info-gdb-mi-command unsupported-command
     ^done,command={exists="false"}

And here is an example where the GDB/MI command is known to the
debugger:

     -info-gdb-mi-command symbol-list-lines
     ^done,command={exists="true"}

The '-list-features' Command
----------------------------

Returns a list of particular features of the MI protocol that this
version of gdb implements.  A feature can be a command, or a new field
in an output of some command, or even an important bugfix.  While a
frontend can sometimes detect presence of a feature at runtime, it is
easier to perform detection at debugger startup.

   The command returns a list of strings, with each string naming an
available feature.  Each returned string is just a name, it does not
have any internal structure.  The list of possible feature names is
given below.

   Example output:

     (gdb) -list-features
     ^done,result=["feature1","feature2"]

   The current list of features is:

'frozen-varobjs'
     Indicates support for the '-var-set-frozen' command, as well as
     possible presence of the 'frozen' field in the output of
     '-varobj-create'.
'pending-breakpoints'
     Indicates support for the '-f' option to the '-break-insert'
     command.
'python'
     Indicates Python scripting support, Python-based pretty-printing
     commands, and possible presence of the 'display_hint' field in the
     output of '-var-list-children'
'thread-info'
     Indicates support for the '-thread-info' command.
'data-read-memory-bytes'
     Indicates support for the '-data-read-memory-bytes' and the
     '-data-write-memory-bytes' commands.
'breakpoint-notifications'
     Indicates that changes to breakpoints and breakpoints created via
     the CLI will be announced via async records.
'ada-task-info'
     Indicates support for the '-ada-task-info' command.
'language-option'
     Indicates that all GDB/MI commands accept the '--language' option
     (*note Context management::).
'info-gdb-mi-command'
     Indicates support for the '-info-gdb-mi-command' command.
'undefined-command-error-code'
     Indicates support for the "undefined-command" error code in error
     result records, produced when trying to execute an undefined GDB/MI
     command (*note GDB/MI Result Records::).
'exec-run-start-option'
     Indicates that the '-exec-run' command supports the '--start'
     option (*note GDB/MI Program Execution::).
'data-disassemble-a-option'
     Indicates that the '-data-disassemble' command supports the '-a'
     option (*note GDB/MI Data Manipulation::).

The '-list-target-features' Command
-----------------------------------

Returns a list of particular features that are supported by the target.
Those features affect the permitted MI commands, but unlike the features
reported by the '-list-features' command, the features depend on which
target GDB is using at the moment.  Whenever a target can change, due to
commands such as '-target-select', '-target-attach' or '-exec-run', the
list of target features may change, and the frontend should obtain it
again.  Example output:

     (gdb) -list-target-features
     ^done,result=["async"]

   The current list of features is:

'async'
     Indicates that the target is capable of asynchronous command
     execution, which means that GDB will accept further commands while
     the target is running.

'reverse'
     Indicates that the target is capable of reverse execution.  *Note
     Reverse Execution::, for more information.


File: gdb.info,  Node: GDB/MI Miscellaneous Commands,  Prev: GDB/MI Support Commands,  Up: GDB/MI

27.24 Miscellaneous GDB/MI Commands
===================================

The '-gdb-exit' Command
-----------------------

Synopsis
........

      -gdb-exit

   Exit GDB immediately.

GDB Command
...........

Approximately corresponds to 'quit'.

Example
.......

     (gdb)
     -gdb-exit
     ^exit

The '-gdb-set' Command
----------------------

Synopsis
........

      -gdb-set

   Set an internal GDB variable.

GDB Command
...........

The corresponding GDB command is 'set'.

Example
.......

     (gdb)
     -gdb-set $foo=3
     ^done
     (gdb)

The '-gdb-show' Command
-----------------------

Synopsis
........

      -gdb-show

   Show the current value of a GDB variable.

GDB Command
...........

The corresponding GDB command is 'show'.

Example
.......

     (gdb)
     -gdb-show annotate
     ^done,value="0"
     (gdb)

The '-gdb-version' Command
--------------------------

Synopsis
........

      -gdb-version

   Show version information for GDB.  Used mostly in testing.

GDB Command
...........

The GDB equivalent is 'show version'.  GDB by default shows this
information when you start an interactive session.

Example
.......

     (gdb)
     -gdb-version
     ~GNU gdb 5.2.1
     ~Copyright 2000 Free Software Foundation, Inc.
     ~GDB is free software, covered by the GNU General Public License, and
     ~you are welcome to change it and/or distribute copies of it under
     ~ certain conditions.
     ~Type "show copying" to see the conditions.
     ~There is absolutely no warranty for GDB.  Type "show warranty" for
     ~ details.
     ~This GDB was configured as
      "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi".
     ^done
     (gdb)

The '-list-thread-groups' Command
---------------------------------

Synopsis
--------

     -list-thread-groups [ --available ] [ --recurse 1 ] [ GROUP ... ]

   Lists thread groups (*note Thread groups::).  When a single thread
group is passed as the argument, lists the children of that group.  When
several thread group are passed, lists information about those thread
groups.  Without any parameters, lists information about all top-level
thread groups.

   Normally, thread groups that are being debugged are reported.  With
the '--available' option, GDB reports thread groups available on the
target.

   The output of this command may have either a 'threads' result or a
'groups' result.  The 'thread' result has a list of tuples as value,
with each tuple describing a thread (*note GDB/MI Thread Information::).
The 'groups' result has a list of tuples as value, each tuple describing
a thread group.  If top-level groups are requested (that is, no
parameter is passed), or when several groups are passed, the output
always has a 'groups' result.  The format of the 'group' result is
described below.

   To reduce the number of roundtrips it's possible to list thread
groups together with their children, by passing the '--recurse' option
and the recursion depth.  Presently, only recursion depth of 1 is
permitted.  If this option is present, then every reported thread group
will also include its children, either as 'group' or 'threads' field.

   In general, any combination of option and parameters is permitted,
with the following caveats:

   * When a single thread group is passed, the output will typically be
     the 'threads' result.  Because threads may not contain anything,
     the 'recurse' option will be ignored.

   * When the '--available' option is passed, limited information may be
     available.  In particular, the list of threads of a process might
     be inaccessible.  Further, specifying specific thread groups might
     not give any performance advantage over listing all thread groups.
     The frontend should assume that '-list-thread-groups --available'
     is always an expensive operation and cache the results.

   The 'groups' result is a list of tuples, where each tuple may have
the following fields:

'id'
     Identifier of the thread group.  This field is always present.  The
     identifier is an opaque string; frontends should not try to convert
     it to an integer, even though it might look like one.

'type'
     The type of the thread group.  At present, only 'process' is a
     valid type.

'pid'
     The target-specific process identifier.  This field is only present
     for thread groups of type 'process' and only if the process exists.

'exit-code'
     The exit code of this group's last exited thread, formatted in
     octal.  This field is only present for thread groups of type
     'process' and only if the process is not running.

'num_children'
     The number of children this thread group has.  This field may be
     absent for an available thread group.

'threads'
     This field has a list of tuples as value, each tuple describing a
     thread.  It may be present if the '--recurse' option is specified,
     and it's actually possible to obtain the threads.

'cores'
     This field is a list of integers, each identifying a core that one
     thread of the group is running on.  This field may be absent if
     such information is not available.

'executable'
     The name of the executable file that corresponds to this thread
     group.  The field is only present for thread groups of type
     'process', and only if there is a corresponding executable file.

Example
-------

     (gdb)
     -list-thread-groups
     ^done,groups=[{id="17",type="process",pid="yyy",num_children="2"}]
     -list-thread-groups 17
     ^done,threads=[{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
        frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]},state="running"},
     {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
        frame={level="0",addr="0x0804891f",func="foo",args=[{name="i",value="10"}],
                file="/tmp/a.c",fullname="/tmp/a.c",line="158",arch="i386:x86_64"},state="running"}]]
     -list-thread-groups --available
     ^done,groups=[{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]}]
     -list-thread-groups --available --recurse 1
      ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
                     threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]},
                              {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},..]
     -list-thread-groups --available --recurse 1 17 18
     ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
                    threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]},
                             {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},...]

The '-info-os' Command
----------------------

Synopsis
........

     -info-os [ TYPE ]

   If no argument is supplied, the command returns a table of available
operating-system-specific information types.  If one of these types is
supplied as an argument TYPE, then the command returns a table of data
of that type.

   The types of information available depend on the target operating
system.

GDB Command
...........

The corresponding GDB command is 'info os'.

Example
.......

When run on a GNU/Linux system, the output will look something like
this:

     (gdb)
     -info-os
     ^done,OSDataTable={nr_rows="10",nr_cols="3",
     hdr=[{width="10",alignment="-1",col_name="col0",colhdr="Type"},
          {width="10",alignment="-1",col_name="col1",colhdr="Description"},
          {width="10",alignment="-1",col_name="col2",colhdr="Title"}],
     body=[item={col0="cpus",col1="Listing of all cpus/cores on the system",
                 col2="CPUs"},
           item={col0="files",col1="Listing of all file descriptors",
                 col2="File descriptors"},
           item={col0="modules",col1="Listing of all loaded kernel modules",
                 col2="Kernel modules"},
           item={col0="msg",col1="Listing of all message queues",
                 col2="Message queues"},
           item={col0="processes",col1="Listing of all processes",
                 col2="Processes"},
           item={col0="procgroups",col1="Listing of all process groups",
                 col2="Process groups"},
           item={col0="semaphores",col1="Listing of all semaphores",
                 col2="Semaphores"},
           item={col0="shm",col1="Listing of all shared-memory regions",
                 col2="Shared-memory regions"},
           item={col0="sockets",col1="Listing of all internet-domain sockets",
                 col2="Sockets"},
           item={col0="threads",col1="Listing of all threads",
                 col2="Threads"}]
     (gdb)
     -info-os processes
     ^done,OSDataTable={nr_rows="190",nr_cols="4",
     hdr=[{width="10",alignment="-1",col_name="col0",colhdr="pid"},
          {width="10",alignment="-1",col_name="col1",colhdr="user"},
          {width="10",alignment="-1",col_name="col2",colhdr="command"},
          {width="10",alignment="-1",col_name="col3",colhdr="cores"}],
     body=[item={col0="1",col1="root",col2="/sbin/init",col3="0"},
           item={col0="2",col1="root",col2="[kthreadd]",col3="1"},
           item={col0="3",col1="root",col2="[ksoftirqd/0]",col3="0"},
           ...
           item={col0="26446",col1="stan",col2="bash",col3="0"},
           item={col0="28152",col1="stan",col2="bash",col3="1"}]}
     (gdb)

   (Note that the MI output here includes a '"Title"' column that does
not appear in command-line 'info os'; this column is useful for MI
clients that want to enumerate the types of data, such as in a popup
menu, but is needless clutter on the command line, and 'info os' omits
it.)

The '-add-inferior' Command
---------------------------

Synopsis
--------

     -add-inferior [ --no-connection ]

   Creates a new inferior (*note Inferiors Connections and Programs::).
The created inferior is not associated with any executable.  Such
association may be established with the '-file-exec-and-symbols' command
(*note GDB/MI File Commands::).

   By default, the new inferior begins connected to the same target
connection as the current inferior.  For example, if the current
inferior was connected to 'gdbserver' with 'target remote', then the new
inferior will be connected to the same 'gdbserver' instance.  The
'--no-connection' option starts the new inferior with no connection yet.
You can then for example use the '-target-select remote' command to
connect to some other 'gdbserver' instance, use '-exec-run' to spawn a
local program, etc.

   The command response always has a field, INFERIOR, whose value is the
identifier of the thread group corresponding to the new inferior.

   An additional section field, CONNECTION, is optional.  This field
will only exist if the new inferior has a target connection.  If this
field exists, then its value will be a tuple containing the following
fields:

'number'
     The number of the connection used for the new inferior.

'name'
     The name of the connection type used for the new inferior.

GDB Command
-----------

The corresponding GDB command is 'add-inferior' (*note 'add-inferior':
add_inferior_cli.).

Example
-------

     (gdb)
     -add-inferior
     ^done,inferior="i3"

The '-interpreter-exec' Command
-------------------------------

Synopsis
--------

     -interpreter-exec INTERPRETER COMMAND

   Execute the specified COMMAND in the given INTERPRETER.

GDB Command
-----------

The corresponding GDB command is 'interpreter-exec'.

Example
-------

     (gdb)
     -interpreter-exec console "break main"
     &"During symbol reading, couldn't parse type; debugger out of date?.\n"
     &"During symbol reading, bad structure-type format.\n"
     ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n"
     ^done
     (gdb)

The '-inferior-tty-set' Command
-------------------------------

Synopsis
--------

     -inferior-tty-set /dev/pts/1

   Set terminal for future runs of the program being debugged.

GDB Command
-----------

The corresponding GDB command is 'set inferior-tty' /dev/pts/1.

Example
-------

     (gdb)
     -inferior-tty-set /dev/pts/1
     ^done
     (gdb)

The '-inferior-tty-show' Command
--------------------------------

Synopsis
--------

     -inferior-tty-show

   Show terminal for future runs of program being debugged.

GDB Command
-----------

The corresponding GDB command is 'show inferior-tty'.

Example
-------

     (gdb)
     -inferior-tty-set /dev/pts/1
     ^done
     (gdb)
     -inferior-tty-show
     ^done,inferior_tty_terminal="/dev/pts/1"
     (gdb)

The '-enable-timings' Command
-----------------------------

Synopsis
--------

     -enable-timings [yes | no]

   Toggle the printing of the wallclock, user and system times for an MI
command as a field in its output.  This command is to help frontend
developers optimize the performance of their code.  No argument is
equivalent to 'yes'.

GDB Command
-----------

No equivalent.

Example
-------

     (gdb)
     -enable-timings
     ^done
     (gdb)
     -break-insert main
     ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x080484ed",func="main",file="myprog.c",
     fullname="/home/nickrob/myprog.c",line="73",thread-groups=["i1"],
     times="0"},
     time={wallclock="0.05185",user="0.00800",system="0.00000"}
     (gdb)
     -enable-timings no
     ^done
     (gdb)
     -exec-run
     ^running
     (gdb)
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
     frame={addr="0x080484ed",func="main",args=[{name="argc",value="1"},
     {name="argv",value="0xbfb60364"}],file="myprog.c",
     fullname="/home/nickrob/myprog.c",line="73",arch="i386:x86_64"}
     (gdb)

The '-complete' Command
-----------------------

Synopsis
--------

     -complete COMMAND

   Show a list of completions for partially typed CLI COMMAND.

   This command is intended for GDB/MI frontends that cannot use two
separate CLI and MI channels -- for example: because of lack of PTYs
like on Windows or because GDB is used remotely via a SSH connection.

Result
------

The result consists of two or three fields:

'completion'
     This field contains the completed COMMAND.  If COMMAND has no known
     completions, this field is omitted.

'matches'
     This field contains a (possibly empty) array of matches.  It is
     always present.

'max_completions_reached'
     This field contains '1' if number of known completions is above
     'max-completions' limit (*note Completion::), otherwise it contains
     '0'.  It is always present.

GDB Command
-----------

The corresponding GDB command is 'complete'.

Example
-------

     (gdb)
     -complete br
     ^done,completion="break",
           matches=["break","break-range"],
           max_completions_reached="0"
     (gdb)
     -complete "b ma"
     ^done,completion="b ma",
           matches=["b madvise","b main"],max_completions_reached="0"
     (gdb)
     -complete "b push_b"
     ^done,completion="b push_back(",
           matches=[
            "b A::push_back(void*)",
            "b std::string::push_back(char)",
            "b std::vector<int, std::allocator<int> >::push_back(int&&)"],
           max_completions_reached="0"
     (gdb)
     -complete "nonexist"
     ^done,matches=[],max_completions_reached="0"
     (gdb)



File: gdb.info,  Node: Annotations,  Next: JIT Interface,  Prev: GDB/MI,  Up: Top

28 GDB Annotations
******************

This chapter describes annotations in GDB.  Annotations were designed to
interface GDB to graphical user interfaces or other similar programs
which want to interact with GDB at a relatively high level.

   The annotation mechanism has largely been superseded by GDB/MI (*note
GDB/MI::).

* Menu:

* Annotations Overview::  What annotations are; the general syntax.
* Server Prefix::       Issuing a command without affecting user state.
* Prompting::           Annotations marking GDB's need for input.
* Errors::              Annotations for error messages.
* Invalidation::        Some annotations describe things now invalid.
* Annotations for Running::
                        Whether the program is running, how it stopped, etc.
* Source Annotations::  Annotations describing source code.


File: gdb.info,  Node: Annotations Overview,  Next: Server Prefix,  Up: Annotations

28.1 What is an Annotation?
===========================

Annotations start with a newline character, two 'control-z' characters,
and the name of the annotation.  If there is no additional information
associated with this annotation, the name of the annotation is followed
immediately by a newline.  If there is additional information, the name
of the annotation is followed by a space, the additional information,
and a newline.  The additional information cannot contain newline
characters.

   Any output not beginning with a newline and two 'control-z'
characters denotes literal output from GDB.  Currently there is no need
for GDB to output a newline followed by two 'control-z' characters, but
if there was such a need, the annotations could be extended with an
'escape' annotation which means those three characters as output.

   The annotation LEVEL, which is specified using the '--annotate'
command line option (*note Mode Options::), controls how much
information GDB prints together with its prompt, values of expressions,
source lines, and other types of output.  Level 0 is for no annotations,
level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 3
is the maximum annotation suitable for programs that control GDB, and
level 2 annotations have been made obsolete (*note Limitations of the
Annotation Interface: (annotate)Limitations.).

'set annotate LEVEL'
     The GDB command 'set annotate' sets the level of annotations to the
     specified LEVEL.

'show annotate'
     Show the current annotation level.

   This chapter describes level 3 annotations.

   A simple example of starting up GDB with annotations is:

     $ gdb --annotate=3
     GNU gdb 6.0
     Copyright 2003 Free Software Foundation, Inc.
     GDB is free software, covered by the GNU General Public License,
     and you are welcome to change it and/or distribute copies of it
     under certain conditions.
     Type "show copying" to see the conditions.
     There is absolutely no warranty for GDB.  Type "show warranty"
     for details.
     This GDB was configured as "i386-pc-linux-gnu"

     ^Z^Zpre-prompt
     (gdb)
     ^Z^Zprompt
     quit

     ^Z^Zpost-prompt
     $

   Here 'quit' is input to GDB; the rest is output from GDB.  The three
lines beginning '^Z^Z' (where '^Z' denotes a 'control-z' character) are
annotations; the rest is output from GDB.


File: gdb.info,  Node: Server Prefix,  Next: Prompting,  Prev: Annotations Overview,  Up: Annotations

28.2 The Server Prefix
======================

If you prefix a command with 'server ' then it will not affect the
command history, nor will it affect GDB's notion of which command to
repeat if <RET> is pressed on a line by itself.  This means that
commands can be run behind a user's back by a front-end in a transparent
manner.

   The 'server ' prefix does not affect the recording of values into the
value history; to print a value without recording it into the value
history, use the 'output' command instead of the 'print' command.

   Using this prefix also disables confirmation requests (*note
confirmation requests::).


File: gdb.info,  Node: Prompting,  Next: Errors,  Prev: Server Prefix,  Up: Annotations

28.3 Annotation for GDB Input
=============================

When GDB prompts for input, it annotates this fact so it is possible to
know when to send output, when the output from a given command is over,
etc.

   Different kinds of input each have a different "input type".  Each
input type has three annotations: a 'pre-' annotation, which denotes the
beginning of any prompt which is being output, a plain annotation, which
denotes the end of the prompt, and then a 'post-' annotation which
denotes the end of any echo which may (or may not) be associated with
the input.  For example, the 'prompt' input type features the following
annotations:

     ^Z^Zpre-prompt
     ^Z^Zprompt
     ^Z^Zpost-prompt

   The input types are

'prompt'
     When GDB is prompting for a command (the main GDB prompt).

'commands'
     When GDB prompts for a set of commands, like in the 'commands'
     command.  The annotations are repeated for each command which is
     input.

'overload-choice'
     When GDB wants the user to select between various overloaded
     functions.

'query'
     When GDB wants the user to confirm a potentially dangerous
     operation.

'prompt-for-continue'
     When GDB is asking the user to press return to continue.  Note:
     Don't expect this to work well; instead use 'set height 0' to
     disable prompting.  This is because the counting of lines is buggy
     in the presence of annotations.


File: gdb.info,  Node: Errors,  Next: Invalidation,  Prev: Prompting,  Up: Annotations

28.4 Errors
===========

     ^Z^Zquit

   This annotation occurs right before GDB responds to an interrupt.

     ^Z^Zerror

   This annotation occurs right before GDB responds to an error.

   Quit and error annotations indicate that any annotations which GDB
was in the middle of may end abruptly.  For example, if a
'value-history-begin' annotation is followed by a 'error', one cannot
expect to receive the matching 'value-history-end'.  One cannot expect
not to receive it either, however; an error annotation does not
necessarily mean that GDB is immediately returning all the way to the
top level.

   A quit or error annotation may be preceded by

     ^Z^Zerror-begin

   Any output between that and the quit or error annotation is the error
message.

   Warning messages are not yet annotated.


File: gdb.info,  Node: Invalidation,  Next: Annotations for Running,  Prev: Errors,  Up: Annotations

28.5 Invalidation Notices
=========================

The following annotations say that certain pieces of state may have
changed.

'^Z^Zframes-invalid'

     The frames (for example, output from the 'backtrace' command) may
     have changed.

'^Z^Zbreakpoints-invalid'

     The breakpoints may have changed.  For example, the user just added
     or deleted a breakpoint.


File: gdb.info,  Node: Annotations for Running,  Next: Source Annotations,  Prev: Invalidation,  Up: Annotations

28.6 Running the Program
========================

When the program starts executing due to a GDB command such as 'step' or
'continue',

     ^Z^Zstarting

   is output.  When the program stops,

     ^Z^Zstopped

   is output.  Before the 'stopped' annotation, a variety of annotations
describe how the program stopped.

'^Z^Zexited EXIT-STATUS'
     The program exited, and EXIT-STATUS is the exit status (zero for
     successful exit, otherwise nonzero).

'^Z^Zsignalled'
     The program exited with a signal.  After the '^Z^Zsignalled', the
     annotation continues:

          INTRO-TEXT
          ^Z^Zsignal-name
          NAME
          ^Z^Zsignal-name-end
          MIDDLE-TEXT
          ^Z^Zsignal-string
          STRING
          ^Z^Zsignal-string-end
          END-TEXT

     where NAME is the name of the signal, such as 'SIGILL' or
     'SIGSEGV', and STRING is the explanation of the signal, such as
     'Illegal Instruction' or 'Segmentation fault'.  The arguments
     INTRO-TEXT, MIDDLE-TEXT, and END-TEXT are for the user's benefit
     and have no particular format.

'^Z^Zsignal'
     The syntax of this annotation is just like 'signalled', but GDB is
     just saying that the program received the signal, not that it was
     terminated with it.

'^Z^Zbreakpoint NUMBER'
     The program hit breakpoint number NUMBER.

'^Z^Zwatchpoint NUMBER'
     The program hit watchpoint number NUMBER.


File: gdb.info,  Node: Source Annotations,  Prev: Annotations for Running,  Up: Annotations

28.7 Displaying Source
======================

The following annotation is used instead of displaying source code:

     ^Z^Zsource FILENAME:LINE:CHARACTER:MIDDLE:ADDR

   where FILENAME is an absolute file name indicating which source file,
LINE is the line number within that file (where 1 is the first line in
the file), CHARACTER is the character position within the file (where 0
is the first character in the file) (for most debug formats this will
necessarily point to the beginning of a line), MIDDLE is 'middle' if
ADDR is in the middle of the line, or 'beg' if ADDR is at the beginning
of the line, and ADDR is the address in the target program associated
with the source which is being displayed.  The ADDR is in the form '0x'
followed by one or more lowercase hex digits (note that this does not
depend on the language).


File: gdb.info,  Node: JIT Interface,  Next: In-Process Agent,  Prev: Annotations,  Up: Top

29 JIT Compilation Interface
****************************

This chapter documents GDB's "just-in-time" (JIT) compilation interface.
A JIT compiler is a program or library that generates native executable
code at runtime and executes it, usually in order to achieve good
performance while maintaining platform independence.

   Programs that use JIT compilation are normally difficult to debug
because portions of their code are generated at runtime, instead of
being loaded from object files, which is where GDB normally finds the
program's symbols and debug information.  In order to debug programs
that use JIT compilation, GDB has an interface that allows the program
to register in-memory symbol files with GDB at runtime.

   If you are using GDB to debug a program that uses this interface,
then it should work transparently so long as you have not stripped the
binary.  If you are developing a JIT compiler, then the interface is
documented in the rest of this chapter.  At this time, the only known
client of this interface is the LLVM JIT.

   Broadly speaking, the JIT interface mirrors the dynamic loader
interface.  The JIT compiler communicates with GDB by writing data into
a global variable and calling a function at a well-known symbol.  When
GDB attaches, it reads a linked list of symbol files from the global
variable to find existing code, and puts a breakpoint in the function so
that it can find out about additional code.

* Menu:

* Declarations::                Relevant C struct declarations
* Registering Code::            Steps to register code
* Unregistering Code::          Steps to unregister code
* Custom Debug Info::           Emit debug information in a custom format


File: gdb.info,  Node: Declarations,  Next: Registering Code,  Up: JIT Interface

29.1 JIT Declarations
=====================

These are the relevant struct declarations that a C program should
include to implement the interface:

     typedef enum
     {
       JIT_NOACTION = 0,
       JIT_REGISTER_FN,
       JIT_UNREGISTER_FN
     } jit_actions_t;

     struct jit_code_entry
     {
       struct jit_code_entry *next_entry;
       struct jit_code_entry *prev_entry;
       const char *symfile_addr;
       uint64_t symfile_size;
     };

     struct jit_descriptor
     {
       uint32_t version;
       /* This type should be jit_actions_t, but we use uint32_t
          to be explicit about the bitwidth.  */
       uint32_t action_flag;
       struct jit_code_entry *relevant_entry;
       struct jit_code_entry *first_entry;
     };

     /* GDB puts a breakpoint in this function.  */
     void __attribute__((noinline)) __jit_debug_register_code() { };

     /* Make sure to specify the version statically, because the
        debugger may check the version before we can set it.  */
     struct jit_descriptor __jit_debug_descriptor = { 1, 0, 0, 0 };

   If the JIT is multi-threaded, then it is important that the JIT
synchronize any modifications to this global data properly, which can
easily be done by putting a global mutex around modifications to these
structures.


File: gdb.info,  Node: Registering Code,  Next: Unregistering Code,  Prev: Declarations,  Up: JIT Interface

29.2 Registering Code
=====================

To register code with GDB, the JIT should follow this protocol:

   * Generate an object file in memory with symbols and other desired
     debug information.  The file must include the virtual addresses of
     the sections.

   * Create a code entry for the file, which gives the start and size of
     the symbol file.

   * Add it to the linked list in the JIT descriptor.

   * Point the relevant_entry field of the descriptor at the entry.

   * Set 'action_flag' to 'JIT_REGISTER' and call
     '__jit_debug_register_code'.

   When GDB is attached and the breakpoint fires, GDB uses the
'relevant_entry' pointer so it doesn't have to walk the list looking for
new code.  However, the linked list must still be maintained in order to
allow GDB to attach to a running process and still find the symbol
files.


File: gdb.info,  Node: Unregistering Code,  Next: Custom Debug Info,  Prev: Registering Code,  Up: JIT Interface

29.3 Unregistering Code
=======================

If code is freed, then the JIT should use the following protocol:

   * Remove the code entry corresponding to the code from the linked
     list.

   * Point the 'relevant_entry' field of the descriptor at the code
     entry.

   * Set 'action_flag' to 'JIT_UNREGISTER' and call
     '__jit_debug_register_code'.

   If the JIT frees or recompiles code without unregistering it, then
GDB and the JIT will leak the memory used for the associated symbol
files.


File: gdb.info,  Node: Custom Debug Info,  Prev: Unregistering Code,  Up: JIT Interface

29.4 Custom Debug Info
======================

Generating debug information in platform-native file formats (like ELF
or COFF) may be an overkill for JIT compilers; especially if all the
debug info is used for is displaying a meaningful backtrace.  The issue
can be resolved by having the JIT writers decide on a debug info format
and also provide a reader that parses the debug info generated by the
JIT compiler.  This section gives a brief overview on writing such a
parser.  More specific details can be found in the source file
'gdb/jit-reader.in', which is also installed as a header at
'INCLUDEDIR/gdb/jit-reader.h' for easy inclusion.

   The reader is implemented as a shared object (so this functionality
is not available on platforms which don't allow loading shared objects
at runtime).  Two GDB commands, 'jit-reader-load' and
'jit-reader-unload' are provided, to be used to load and unload the
readers from a preconfigured directory.  Once loaded, the shared object
is used the parse the debug information emitted by the JIT compiler.

* Menu:

* Using JIT Debug Info Readers::       How to use supplied readers correctly
* Writing JIT Debug Info Readers::     Creating a debug-info reader


File: gdb.info,  Node: Using JIT Debug Info Readers,  Next: Writing JIT Debug Info Readers,  Up: Custom Debug Info

29.4.1 Using JIT Debug Info Readers
-----------------------------------

Readers can be loaded and unloaded using the 'jit-reader-load' and
'jit-reader-unload' commands.

'jit-reader-load READER'
     Load the JIT reader named READER, which is a shared object
     specified as either an absolute or a relative file name.  In the
     latter case, GDB will try to load the reader from a pre-configured
     directory, usually 'LIBDIR/gdb/' on a UNIX system (here LIBDIR is
     the system library directory, often '/usr/local/lib').

     Only one reader can be active at a time; trying to load a second
     reader when one is already loaded will result in GDB reporting an
     error.  A new JIT reader can be loaded by first unloading the
     current one using 'jit-reader-unload' and then invoking
     'jit-reader-load'.

'jit-reader-unload'
     Unload the currently loaded JIT reader.


File: gdb.info,  Node: Writing JIT Debug Info Readers,  Prev: Using JIT Debug Info Readers,  Up: Custom Debug Info

29.4.2 Writing JIT Debug Info Readers
-------------------------------------

As mentioned, a reader is essentially a shared object conforming to a
certain ABI. This ABI is described in 'jit-reader.h'.

   'jit-reader.h' defines the structures, macros and functions required
to write a reader.  It is installed (along with GDB), in
'INCLUDEDIR/gdb' where INCLUDEDIR is the system include directory.

   Readers need to be released under a GPL compatible license.  A reader
can be declared as released under such a license by placing the macro
'GDB_DECLARE_GPL_COMPATIBLE_READER' in a source file.

   The entry point for readers is the symbol 'gdb_init_reader', which is
expected to be a function with the prototype

     extern struct gdb_reader_funcs *gdb_init_reader (void);

   'struct gdb_reader_funcs' contains a set of pointers to callback
functions.  These functions are executed to read the debug info
generated by the JIT compiler ('read'), to unwind stack frames
('unwind') and to create canonical frame IDs ('get_frame_id').  It also
has a callback that is called when the reader is being unloaded
('destroy').  The struct looks like this

     struct gdb_reader_funcs
     {
       /* Must be set to GDB_READER_INTERFACE_VERSION.  */
       int reader_version;

       /* For use by the reader.  */
       void *priv_data;

       gdb_read_debug_info *read;
       gdb_unwind_frame *unwind;
       gdb_get_frame_id *get_frame_id;
       gdb_destroy_reader *destroy;
     };

   The callbacks are provided with another set of callbacks by GDB to do
their job.  For 'read', these callbacks are passed in a 'struct
gdb_symbol_callbacks' and for 'unwind' and 'get_frame_id', in a 'struct
gdb_unwind_callbacks'.  'struct gdb_symbol_callbacks' has callbacks to
create new object files and new symbol tables inside those object files.
'struct gdb_unwind_callbacks' has callbacks to read registers off the
current frame and to write out the values of the registers in the
previous frame.  Both have a callback ('target_read') to read bytes off
the target's address space.


File: gdb.info,  Node: In-Process Agent,  Next: GDB Bugs,  Prev: JIT Interface,  Up: Top

30 In-Process Agent
*******************

The traditional debugging model is conceptually low-speed, but works
fine, because most bugs can be reproduced in debugging-mode execution.
However, as multi-core or many-core processors are becoming mainstream,
and multi-threaded programs become more and more popular, there should
be more and more bugs that only manifest themselves at normal-mode
execution, for example, thread races, because debugger's interference
with the program's timing may conceal the bugs.  On the other hand, in
some applications, it is not feasible for the debugger to interrupt the
program's execution long enough for the developer to learn anything
helpful about its behavior.  If the program's correctness depends on its
real-time behavior, delays introduced by a debugger might cause the
program to fail, even when the code itself is correct.  It is useful to
be able to observe the program's behavior without interrupting it.

   Therefore, traditional debugging model is too intrusive to reproduce
some bugs.  In order to reduce the interference with the program, we can
reduce the number of operations performed by debugger.  The "In-Process
Agent", a shared library, is running within the same process with
inferior, and is able to perform some debugging operations itself.  As a
result, debugger is only involved when necessary, and performance of
debugging can be improved accordingly.  Note that interference with
program can be reduced but can't be removed completely, because the
in-process agent will still stop or slow down the program.

   The in-process agent can interpret and execute Agent Expressions
(*note Agent Expressions::) during performing debugging operations.  The
agent expressions can be used for different purposes, such as collecting
data in tracepoints, and condition evaluation in breakpoints.

   You can control whether the in-process agent is used as an aid for
debugging with the following commands:

'set agent on'
     Causes the in-process agent to perform some operations on behalf of
     the debugger.  Just which operations requested by the user will be
     done by the in-process agent depends on the its capabilities.  For
     example, if you request to evaluate breakpoint conditions in the
     in-process agent, and the in-process agent has such capability as
     well, then breakpoint conditions will be evaluated in the
     in-process agent.

'set agent off'
     Disables execution of debugging operations by the in-process agent.
     All of the operations will be performed by GDB.

'show agent'
     Display the current setting of execution of debugging operations by
     the in-process agent.

* Menu:

* In-Process Agent Protocol::


File: gdb.info,  Node: In-Process Agent Protocol,  Up: In-Process Agent

30.1 In-Process Agent Protocol
==============================

The in-process agent is able to communicate with both GDB and GDBserver
(*note In-Process Agent::).  This section documents the protocol used
for communications between GDB or GDBserver and the IPA. In general, GDB
or GDBserver sends commands (*note IPA Protocol Commands::) and data to
in-process agent, and then in-process agent replies back with the return
result of the command, or some other information.  The data sent to
in-process agent is composed of primitive data types, such as 4-byte or
8-byte type, and composite types, which are called objects (*note IPA
Protocol Objects::).

* Menu:

* IPA Protocol Objects::
* IPA Protocol Commands::


File: gdb.info,  Node: IPA Protocol Objects,  Next: IPA Protocol Commands,  Up: In-Process Agent Protocol

30.1.1 IPA Protocol Objects
---------------------------

The commands sent to and results received from agent may contain some
complex data types called "objects".

   The in-process agent is running on the same machine with GDB or
GDBserver, so it doesn't have to handle as much differences between two
ends as remote protocol (*note Remote Protocol::) tries to handle.
However, there are still some differences of two ends in two processes:

  1. word size.  On some 64-bit machines, GDB or GDBserver can be
     compiled as a 64-bit executable, while in-process agent is a 32-bit
     one.
  2. ABI. Some machines may have multiple types of ABI, GDB or GDBserver
     is compiled with one, and in-process agent is compiled with the
     other one.

   Here are the IPA Protocol Objects:

  1. agent expression object.  It represents an agent expression (*note
     Agent Expressions::).
  2. tracepoint action object.  It represents a tracepoint action (*note
     Tracepoint Action Lists: Tracepoint Actions.) to collect registers,
     memory, static trace data and to evaluate expression.
  3. tracepoint object.  It represents a tracepoint (*note
     Tracepoints::).

   The following table describes important attributes of each IPA
protocol object:

Name                   Size           Description
---------------------------------------------------------------------------
_agent expression
object_
length                 4              length of bytes code
byte code              LENGTH         contents of byte code
_tracepoint action
for collecting
memory_
'M'                    1              type of tracepoint action
addr                   8              if BASEREG is '-1', ADDR is the
                                      address of the lowest byte to
                                      collect, otherwise ADDR is the
                                      offset of BASEREG for memory
                                      collecting.
len                    8              length of memory for collecting
basereg                4              the register number containing the
                                      starting memory address for
                                      collecting.
_tracepoint action
for collecting
registers_
'R'                    1              type of tracepoint action
_tracepoint action
for collecting
static trace data_
'L'                    1              type of tracepoint action
_tracepoint action
for expression
evaluation_
'X'                    1              type of tracepoint action
agent expression       length of      *note agent expression object::
_tracepoint object_
number                 4              number of tracepoint
address                8              address of tracepoint inserted on
type                   4              type of tracepoint
enabled                1              enable or disable of tracepoint
step_count             8              step
pass_count             8              pass
numactions             4              number of tracepoint actions
hit count              8              hit count
trace frame usage      8              trace frame usage
compiled_cond          8              compiled condition
orig_size              8              orig size
condition              4 if           zero if condition is NULL,
                       condition is   otherwise is
                       NULL           *note agent expression object::
                       otherwise
                       length of
                       *note agent expression object::
actions                variable       numactions number of
                                      *note tracepoint action object::


File: gdb.info,  Node: IPA Protocol Commands,  Prev: IPA Protocol Objects,  Up: In-Process Agent Protocol

30.1.2 IPA Protocol Commands
----------------------------

The spaces in each command are delimiters to ease reading this commands
specification.  They don't exist in real commands.

'FastTrace:TRACEPOINT_OBJECT GDB_JUMP_PAD_HEAD'
     Installs a new fast tracepoint described by TRACEPOINT_OBJECT
     (*note tracepoint object::).  The GDB_JUMP_PAD_HEAD, 8-byte long,
     is the head of "jumppad", which is used to jump to data collection
     routine in IPA finally.

     Replies:
     'OK TARGET_ADDRESS GDB_JUMP_PAD_HEAD FJUMP_SIZE FJUMP'
          TARGET_ADDRESS is address of tracepoint in the inferior.  The
          GDB_JUMP_PAD_HEAD is updated head of jumppad.  Both of
          TARGET_ADDRESS and GDB_JUMP_PAD_HEAD are 8-byte long.  The
          FJUMP contains a sequence of instructions jump to jumppad
          entry.  The FJUMP_SIZE, 4-byte long, is the size of FJUMP.
     'E NN'
          for an error

'close'
     Closes the in-process agent.  This command is sent when GDB or
     GDBserver is about to kill inferiors.

'qTfSTM'
     *Note qTfSTM::.
'qTsSTM'
     *Note qTsSTM::.
'qTSTMat'
     *Note qTSTMat::.
'probe_marker_at:ADDRESS'
     Asks in-process agent to probe the marker at ADDRESS.

     Replies:
     'E NN'
          for an error
'unprobe_marker_at:ADDRESS'
     Asks in-process agent to unprobe the marker at ADDRESS.


File: gdb.info,  Node: GDB Bugs,  Next: Command Line Editing,  Prev: In-Process Agent,  Up: Top

31 Reporting Bugs in GDB
************************

Your bug reports play an essential role in making GDB reliable.

   Reporting a bug may help you by bringing a solution to your problem,
or it may not.  But in any case the principal function of a bug report
is to help the entire community by making the next version of GDB work
better.  Bug reports are your contribution to the maintenance of GDB.

   In order for a bug report to serve its purpose, you must include the
information that enables us to fix the bug.

* Menu:

* Bug Criteria::                Have you found a bug?
* Bug Reporting::               How to report bugs


File: gdb.info,  Node: Bug Criteria,  Next: Bug Reporting,  Up: GDB Bugs

31.1 Have You Found a Bug?
==========================

If you are not sure whether you have found a bug, here are some
guidelines:

   * If the debugger gets a fatal signal, for any input whatever, that
     is a GDB bug.  Reliable debuggers never crash.

   * If GDB produces an error message for valid input, that is a bug.
     (Note that if you're cross debugging, the problem may also be
     somewhere in the connection to the target.)

   * If GDB does not produce an error message for invalid input, that is
     a bug.  However, you should note that your idea of "invalid input"
     might be our idea of "an extension" or "support for traditional
     practice".

   * If you are an experienced user of debugging tools, your suggestions
     for improvement of GDB are welcome in any case.


File: gdb.info,  Node: Bug Reporting,  Prev: Bug Criteria,  Up: GDB Bugs

31.2 How to Report Bugs
=======================

A number of companies and individuals offer support for GNU products.
If you obtained GDB from a support organization, we recommend you
contact that organization first.

   You can find contact information for many support companies and
individuals in the file 'etc/SERVICE' in the GNU Emacs distribution.

   In any event, we also recommend that you submit bug reports for GDB
to <https://www.gnu.org/software/gdb/bugs/>.

   The fundamental principle of reporting bugs usefully is this: *report
all the facts*.  If you are not sure whether to state a fact or leave it
out, state it!

   Often people omit facts because they think they know what causes the
problem and assume that some details do not matter.  Thus, you might
assume that the name of the variable you use in an example does not
matter.  Well, probably it does not, but one cannot be sure.  Perhaps
the bug is a stray memory reference which happens to fetch from the
location where that name is stored in memory; perhaps, if the name were
different, the contents of that location would fool the debugger into
doing the right thing despite the bug.  Play it safe and give a
specific, complete example.  That is the easiest thing for you to do,
and the most helpful.

   Keep in mind that the purpose of a bug report is to enable us to fix
the bug.  It may be that the bug has been reported previously, but
neither you nor we can know that unless your bug report is complete and
self-contained.

   Sometimes people give a few sketchy facts and ask, "Does this ring a
bell?"  Those bug reports are useless, and we urge everyone to _refuse
to respond to them_ except to chide the sender to report bugs properly.

   To enable us to fix the bug, you should include all these things:

   * The version of GDB.  GDB announces it if you start with no
     arguments; you can also print it at any time using 'show version'.

     Without this, we will not know whether there is any point in
     looking for the bug in the current version of GDB.

   * The type of machine you are using, and the operating system name
     and version number.

   * The details of the GDB build-time configuration.  GDB shows these
     details if you invoke it with the '--configuration' command-line
     option, or if you type 'show configuration' at GDB's prompt.

   * What compiler (and its version) was used to compile GDB--e.g.
     "gcc-2.8.1".

   * What compiler (and its version) was used to compile the program you
     are debugging--e.g. "gcc-2.8.1", or "HP92453-01 A.10.32.03 HP C
     Compiler".  For GCC, you can say 'gcc --version' to get this
     information; for other compilers, see the documentation for those
     compilers.

   * The command arguments you gave the compiler to compile your example
     and observe the bug.  For example, did you use '-O'?  To guarantee
     you will not omit something important, list them all.  A copy of
     the Makefile (or the output from make) is sufficient.

     If we were to try to guess the arguments, we would probably guess
     wrong and then we might not encounter the bug.

   * A complete input script, and all necessary source files, that will
     reproduce the bug.

   * A description of what behavior you observe that you believe is
     incorrect.  For example, "It gets a fatal signal."

     Of course, if the bug is that GDB gets a fatal signal, then we will
     certainly notice it.  But if the bug is incorrect output, we might
     not notice unless it is glaringly wrong.  You might as well not
     give us a chance to make a mistake.

     Even if the problem you experience is a fatal signal, you should
     still say so explicitly.  Suppose something strange is going on,
     such as, your copy of GDB is out of synch, or you have encountered
     a bug in the C library on your system.  (This has happened!)  Your
     copy might crash and ours would not.  If you told us to expect a
     crash, then when ours fails to crash, we would know that the bug
     was not happening for us.  If you had not told us to expect a
     crash, then we would not be able to draw any conclusion from our
     observations.

     To collect all this information, you can use a session recording
     program such as 'script', which is available on many Unix systems.
     Just run your GDB session inside 'script' and then include the
     'typescript' file with your bug report.

     Another way to record a GDB session is to run GDB inside Emacs and
     then save the entire buffer to a file.

   * If you wish to suggest changes to the GDB source, send us context
     diffs.  If you even discuss something in the GDB source, refer to
     it by context, not by line number.

     The line numbers in our development sources will not match those in
     your sources.  Your line numbers would convey no useful information
     to us.

   Here are some things that are not necessary:

   * A description of the envelope of the bug.

     Often people who encounter a bug spend a lot of time investigating
     which changes to the input file will make the bug go away and which
     changes will not affect it.

     This is often time consuming and not very useful, because the way
     we will find the bug is by running a single example under the
     debugger with breakpoints, not by pure deduction from a series of
     examples.  We recommend that you save your time for something else.

     Of course, if you can find a simpler example to report _instead_ of
     the original one, that is a convenience for us.  Errors in the
     output will be easier to spot, running under the debugger will take
     less time, and so on.

     However, simplification is not vital; if you do not want to do
     this, report the bug anyway and send us the entire test case you
     used.

   * A patch for the bug.

     A patch for the bug does help us if it is a good one.  But do not
     omit the necessary information, such as the test case, on the
     assumption that a patch is all we need.  We might see problems with
     your patch and decide to fix the problem another way, or we might
     not understand it at all.

     Sometimes with a program as complicated as GDB it is very hard to
     construct an example that will make the program follow a certain
     path through the code.  If you do not send us the example, we will
     not be able to construct one, so we will not be able to verify that
     the bug is fixed.

     And if we cannot understand what bug you are trying to fix, or why
     your patch should be an improvement, we will not install it.  A
     test case will help us to understand.

   * A guess about what the bug is or what it depends on.

     Such guesses are usually wrong.  Even we cannot guess right about
     such things without first using the debugger to find the facts.


File: gdb.info,  Node: Command Line Editing,  Next: Using History Interactively,  Prev: GDB Bugs,  Up: Top

32 Command Line Editing
***********************

This chapter describes the basic features of the GNU command line
editing interface.

* Menu:

* Introduction and Notation::	Notation used in this text.
* Readline Interaction::	The minimum set of commands for editing a line.
* Readline Init File::		Customizing Readline from a user's view.
* Bindable Readline Commands::	A description of most of the Readline commands
				available for binding
* Readline vi Mode::		A short description of how to make Readline
				behave like the vi editor.


File: gdb.info,  Node: Introduction and Notation,  Next: Readline Interaction,  Up: Command Line Editing

32.1 Introduction to Line Editing
=================================

The following paragraphs describe the notation used to represent
keystrokes.

   The text 'C-k' is read as 'Control-K' and describes the character
produced when the <k> key is pressed while the Control key is depressed.

   The text 'M-k' is read as 'Meta-K' and describes the character
produced when the Meta key (if you have one) is depressed, and the <k>
key is pressed.  The Meta key is labeled <ALT> on many keyboards.  On
keyboards with two keys labeled <ALT> (usually to either side of the
space bar), the <ALT> on the left side is generally set to work as a
Meta key.  The <ALT> key on the right may also be configured to work as
a Meta key or may be configured as some other modifier, such as a
Compose key for typing accented characters.

   If you do not have a Meta or <ALT> key, or another key working as a
Meta key, the identical keystroke can be generated by typing <ESC>
_first_, and then typing <k>.  Either process is known as "metafying"
the <k> key.

   The text 'M-C-k' is read as 'Meta-Control-k' and describes the
character produced by "metafying" 'C-k'.

   In addition, several keys have their own names.  Specifically, <DEL>,
<ESC>, <LFD>, <SPC>, <RET>, and <TAB> all stand for themselves when seen
in this text, or in an init file (*note Readline Init File::).  If your
keyboard lacks a <LFD> key, typing <C-j> will produce the desired
character.  The <RET> key may be labeled <Return> or <Enter> on some
keyboards.


File: gdb.info,  Node: Readline Interaction,  Next: Readline Init File,  Prev: Introduction and Notation,  Up: Command Line Editing

32.2 Readline Interaction
=========================

Often during an interactive session you type in a long line of text,
only to notice that the first word on the line is misspelled.  The
Readline library gives you a set of commands for manipulating the text
as you type it in, allowing you to just fix your typo, and not forcing
you to retype the majority of the line.  Using these editing commands,
you move the cursor to the place that needs correction, and delete or
insert the text of the corrections.  Then, when you are satisfied with
the line, you simply press <RET>.  You do not have to be at the end of
the line to press <RET>; the entire line is accepted regardless of the
location of the cursor within the line.

* Menu:

* Readline Bare Essentials::	The least you need to know about Readline.
* Readline Movement Commands::	Moving about the input line.
* Readline Killing Commands::	How to delete text, and how to get it back!
* Readline Arguments::		Giving numeric arguments to commands.
* Searching::			Searching through previous lines.


File: gdb.info,  Node: Readline Bare Essentials,  Next: Readline Movement Commands,  Up: Readline Interaction

32.2.1 Readline Bare Essentials
-------------------------------

In order to enter characters into the line, simply type them.  The typed
character appears where the cursor was, and then the cursor moves one
space to the right.  If you mistype a character, you can use your erase
character to back up and delete the mistyped character.

   Sometimes you may mistype a character, and not notice the error until
you have typed several other characters.  In that case, you can type
'C-b' to move the cursor to the left, and then correct your mistake.
Afterwards, you can move the cursor to the right with 'C-f'.

   When you add text in the middle of a line, you will notice that
characters to the right of the cursor are 'pushed over' to make room for
the text that you have inserted.  Likewise, when you delete text behind
the cursor, characters to the right of the cursor are 'pulled back' to
fill in the blank space created by the removal of the text.  A list of
the bare essentials for editing the text of an input line follows.

'C-b'
     Move back one character.
'C-f'
     Move forward one character.
<DEL> or <Backspace>
     Delete the character to the left of the cursor.
'C-d'
     Delete the character underneath the cursor.
Printing characters
     Insert the character into the line at the cursor.
'C-_' or 'C-x C-u'
     Undo the last editing command.  You can undo all the way back to an
     empty line.

(Depending on your configuration, the <Backspace> key be set to delete
the character to the left of the cursor and the <DEL> key set to delete
the character underneath the cursor, like 'C-d', rather than the
character to the left of the cursor.)


File: gdb.info,  Node: Readline Movement Commands,  Next: Readline Killing Commands,  Prev: Readline Bare Essentials,  Up: Readline Interaction

32.2.2 Readline Movement Commands
---------------------------------

The above table describes the most basic keystrokes that you need in
order to do editing of the input line.  For your convenience, many other
commands have been added in addition to 'C-b', 'C-f', 'C-d', and <DEL>.
Here are some commands for moving more rapidly about the line.

'C-a'
     Move to the start of the line.
'C-e'
     Move to the end of the line.
'M-f'
     Move forward a word, where a word is composed of letters and
     digits.
'M-b'
     Move backward a word.
'C-l'
     Clear the screen, reprinting the current line at the top.

   Notice how 'C-f' moves forward a character, while 'M-f' moves forward
a word.  It is a loose convention that control keystrokes operate on
characters while meta keystrokes operate on words.


File: gdb.info,  Node: Readline Killing Commands,  Next: Readline Arguments,  Prev: Readline Movement Commands,  Up: Readline Interaction

32.2.3 Readline Killing Commands
--------------------------------

"Killing" text means to delete the text from the line, but to save it
away for later use, usually by "yanking" (re-inserting) it back into the
line.  ('Cut' and 'paste' are more recent jargon for 'kill' and 'yank'.)

   If the description for a command says that it 'kills' text, then you
can be sure that you can get the text back in a different (or the same)
place later.

   When you use a kill command, the text is saved in a "kill-ring".  Any
number of consecutive kills save all of the killed text together, so
that when you yank it back, you get it all.  The kill ring is not line
specific; the text that you killed on a previously typed line is
available to be yanked back later, when you are typing another line.

   Here is the list of commands for killing text.

'C-k'
     Kill the text from the current cursor position to the end of the
     line.

'M-d'
     Kill from the cursor to the end of the current word, or, if between
     words, to the end of the next word.  Word boundaries are the same
     as those used by 'M-f'.

'M-<DEL>'
     Kill from the cursor the start of the current word, or, if between
     words, to the start of the previous word.  Word boundaries are the
     same as those used by 'M-b'.

'C-w'
     Kill from the cursor to the previous whitespace.  This is different
     than 'M-<DEL>' because the word boundaries differ.

   Here is how to "yank" the text back into the line.  Yanking means to
copy the most-recently-killed text from the kill buffer.

'C-y'
     Yank the most recently killed text back into the buffer at the
     cursor.

'M-y'
     Rotate the kill-ring, and yank the new top.  You can only do this
     if the prior command is 'C-y' or 'M-y'.


File: gdb.info,  Node: Readline Arguments,  Next: Searching,  Prev: Readline Killing Commands,  Up: Readline Interaction

32.2.4 Readline Arguments
-------------------------

You can pass numeric arguments to Readline commands.  Sometimes the
argument acts as a repeat count, other times it is the sign of the
argument that is significant.  If you pass a negative argument to a
command which normally acts in a forward direction, that command will
act in a backward direction.  For example, to kill text back to the
start of the line, you might type 'M-- C-k'.

   The general way to pass numeric arguments to a command is to type
meta digits before the command.  If the first 'digit' typed is a minus
sign ('-'), then the sign of the argument will be negative.  Once you
have typed one meta digit to get the argument started, you can type the
remainder of the digits, and then the command.  For example, to give the
'C-d' command an argument of 10, you could type 'M-1 0 C-d', which will
delete the next ten characters on the input line.


File: gdb.info,  Node: Searching,  Prev: Readline Arguments,  Up: Readline Interaction

32.2.5 Searching for Commands in the History
--------------------------------------------

Readline provides commands for searching through the command history for
lines containing a specified string.  There are two search modes:
"incremental" and "non-incremental".

   Incremental searches begin before the user has finished typing the
search string.  As each character of the search string is typed,
Readline displays the next entry from the history matching the string
typed so far.  An incremental search requires only as many characters as
needed to find the desired history entry.  To search backward in the
history for a particular string, type 'C-r'.  Typing 'C-s' searches
forward through the history.  The characters present in the value of the
'isearch-terminators' variable are used to terminate an incremental
search.  If that variable has not been assigned a value, the <ESC> and
'C-J' characters will terminate an incremental search.  'C-g' will abort
an incremental search and restore the original line.  When the search is
terminated, the history entry containing the search string becomes the
current line.

   To find other matching entries in the history list, type 'C-r' or
'C-s' as appropriate.  This will search backward or forward in the
history for the next entry matching the search string typed so far.  Any
other key sequence bound to a Readline command will terminate the search
and execute that command.  For instance, a <RET> will terminate the
search and accept the line, thereby executing the command from the
history list.  A movement command will terminate the search, make the
last line found the current line, and begin editing.

   Readline remembers the last incremental search string.  If two 'C-r's
are typed without any intervening characters defining a new search
string, any remembered search string is used.

   Non-incremental searches read the entire search string before
starting to search for matching history lines.  The search string may be
typed by the user or be part of the contents of the current line.


File: gdb.info,  Node: Readline Init File,  Next: Bindable Readline Commands,  Prev: Readline Interaction,  Up: Command Line Editing

32.3 Readline Init File
=======================

Although the Readline library comes with a set of Emacs-like keybindings
installed by default, it is possible to use a different set of
keybindings.  Any user can customize programs that use Readline by
putting commands in an "inputrc" file, conventionally in his home
directory.  The name of this file is taken from the value of the
environment variable 'INPUTRC'.  If that variable is unset, the default
is '~/.inputrc'.  If that file does not exist or cannot be read, the
ultimate default is '/etc/inputrc'.

   When a program which uses the Readline library starts up, the init
file is read, and the key bindings are set.

   In addition, the 'C-x C-r' command re-reads this init file, thus
incorporating any changes that you might have made to it.

* Menu:

* Readline Init File Syntax::	Syntax for the commands in the inputrc file.

* Conditional Init Constructs::	Conditional key bindings in the inputrc file.

* Sample Init File::		An example inputrc file.


File: gdb.info,  Node: Readline Init File Syntax,  Next: Conditional Init Constructs,  Up: Readline Init File

32.3.1 Readline Init File Syntax
--------------------------------

There are only a few basic constructs allowed in the Readline init file.
Blank lines are ignored.  Lines beginning with a '#' are comments.
Lines beginning with a '$' indicate conditional constructs (*note
Conditional Init Constructs::).  Other lines denote variable settings
and key bindings.

Variable Settings
     You can modify the run-time behavior of Readline by altering the
     values of variables in Readline using the 'set' command within the
     init file.  The syntax is simple:

          set VARIABLE VALUE

     Here, for example, is how to change from the default Emacs-like key
     binding to use 'vi' line editing commands:

          set editing-mode vi

     Variable names and values, where appropriate, are recognized
     without regard to case.  Unrecognized variable names are ignored.

     Boolean variables (those that can be set to on or off) are set to
     on if the value is null or empty, ON (case-insensitive), or 1.  Any
     other value results in the variable being set to off.

     A great deal of run-time behavior is changeable with the following
     variables.

     'bell-style'
          Controls what happens when Readline wants to ring the terminal
          bell.  If set to 'none', Readline never rings the bell.  If
          set to 'visible', Readline uses a visible bell if one is
          available.  If set to 'audible' (the default), Readline
          attempts to ring the terminal's bell.

     'bind-tty-special-chars'
          If set to 'on' (the default), Readline attempts to bind the
          control characters treated specially by the kernel's terminal
          driver to their Readline equivalents.

     'blink-matching-paren'
          If set to 'on', Readline attempts to briefly move the cursor
          to an opening parenthesis when a closing parenthesis is
          inserted.  The default is 'off'.

     'colored-completion-prefix'
          If set to 'on', when listing completions, Readline displays
          the common prefix of the set of possible completions using a
          different color.  The color definitions are taken from the
          value of the 'LS_COLORS' environment variable.  The default is
          'off'.

     'colored-stats'
          If set to 'on', Readline displays possible completions using
          different colors to indicate their file type.  The color
          definitions are taken from the value of the 'LS_COLORS'
          environment variable.  The default is 'off'.

     'comment-begin'
          The string to insert at the beginning of the line when the
          'insert-comment' command is executed.  The default value is
          '"#"'.

     'completion-display-width'
          The number of screen columns used to display possible matches
          when performing completion.  The value is ignored if it is
          less than 0 or greater than the terminal screen width.  A
          value of 0 will cause matches to be displayed one per line.
          The default value is -1.

     'completion-ignore-case'
          If set to 'on', Readline performs filename matching and
          completion in a case-insensitive fashion.  The default value
          is 'off'.

     'completion-map-case'
          If set to 'on', and COMPLETION-IGNORE-CASE is enabled,
          Readline treats hyphens ('-') and underscores ('_') as
          equivalent when performing case-insensitive filename matching
          and completion.  The default value is 'off'.

     'completion-prefix-display-length'
          The length in characters of the common prefix of a list of
          possible completions that is displayed without modification.
          When set to a value greater than zero, common prefixes longer
          than this value are replaced with an ellipsis when displaying
          possible completions.

     'completion-query-items'
          The number of possible completions that determines when the
          user is asked whether the list of possibilities should be
          displayed.  If the number of possible completions is greater
          than or equal to this value, Readline will ask whether or not
          the user wishes to view them; otherwise, they are simply
          listed.  This variable must be set to an integer value greater
          than or equal to 0.  A negative value means Readline should
          never ask.  The default limit is '100'.

     'convert-meta'
          If set to 'on', Readline will convert characters with the
          eighth bit set to an ASCII key sequence by stripping the
          eighth bit and prefixing an <ESC> character, converting them
          to a meta-prefixed key sequence.  The default value is 'on',
          but will be set to 'off' if the locale is one that contains
          eight-bit characters.

     'disable-completion'
          If set to 'On', Readline will inhibit word completion.
          Completion characters will be inserted into the line as if
          they had been mapped to 'self-insert'.  The default is 'off'.

     'echo-control-characters'
          When set to 'on', on operating systems that indicate they
          support it, readline echoes a character corresponding to a
          signal generated from the keyboard.  The default is 'on'.

     'editing-mode'
          The 'editing-mode' variable controls which default set of key
          bindings is used.  By default, Readline starts up in Emacs
          editing mode, where the keystrokes are most similar to Emacs.
          This variable can be set to either 'emacs' or 'vi'.

     'emacs-mode-string'
          If the SHOW-MODE-IN-PROMPT variable is enabled, this string is
          displayed immediately before the last line of the primary
          prompt when emacs editing mode is active.  The value is
          expanded like a key binding, so the standard set of meta- and
          control prefixes and backslash escape sequences is available.
          Use the '\1' and '\2' escapes to begin and end sequences of
          non-printing characters, which can be used to embed a terminal
          control sequence into the mode string.  The default is '@'.

     'enable-bracketed-paste'
          When set to 'On', Readline will configure the terminal in a
          way that will enable it to insert each paste into the editing
          buffer as a single string of characters, instead of treating
          each character as if it had been read from the keyboard.  This
          can prevent pasted characters from being interpreted as
          editing commands.  The default is 'On'.

     'enable-keypad'
          When set to 'on', Readline will try to enable the application
          keypad when it is called.  Some systems need this to enable
          the arrow keys.  The default is 'off'.

     'enable-meta-key'
          When set to 'on', Readline will try to enable any meta
          modifier key the terminal claims to support when it is called.
          On many terminals, the meta key is used to send eight-bit
          characters.  The default is 'on'.

     'expand-tilde'
          If set to 'on', tilde expansion is performed when Readline
          attempts word completion.  The default is 'off'.

     'history-preserve-point'
          If set to 'on', the history code attempts to place the point
          (the current cursor position) at the same location on each
          history line retrieved with 'previous-history' or
          'next-history'.  The default is 'off'.

     'history-size'
          Set the maximum number of history entries saved in the history
          list.  If set to zero, any existing history entries are
          deleted and no new entries are saved.  If set to a value less
          than zero, the number of history entries is not limited.  By
          default, the number of history entries is not limited.  If an
          attempt is made to set HISTORY-SIZE to a non-numeric value,
          the maximum number of history entries will be set to 500.

     'horizontal-scroll-mode'
          This variable can be set to either 'on' or 'off'.  Setting it
          to 'on' means that the text of the lines being edited will
          scroll horizontally on a single screen line when they are
          longer than the width of the screen, instead of wrapping onto
          a new screen line.  This variable is automatically set to 'on'
          for terminals of height 1.  By default, this variable is set
          to 'off'.

     'input-meta'
          If set to 'on', Readline will enable eight-bit input (it will
          not clear the eighth bit in the characters it reads),
          regardless of what the terminal claims it can support.  The
          default value is 'off', but Readline will set it to 'on' if
          the locale contains eight-bit characters.  The name
          'meta-flag' is a synonym for this variable.

     'isearch-terminators'
          The string of characters that should terminate an incremental
          search without subsequently executing the character as a
          command (*note Searching::).  If this variable has not been
          given a value, the characters <ESC> and 'C-J' will terminate
          an incremental search.

     'keymap'
          Sets Readline's idea of the current keymap for key binding
          commands.  Built-in 'keymap' names are 'emacs',
          'emacs-standard', 'emacs-meta', 'emacs-ctlx', 'vi', 'vi-move',
          'vi-command', and 'vi-insert'.  'vi' is equivalent to
          'vi-command' ('vi-move' is also a synonym); 'emacs' is
          equivalent to 'emacs-standard'.  Applications may add
          additional names.  The default value is 'emacs'.  The value of
          the 'editing-mode' variable also affects the default keymap.

     'keyseq-timeout'
          Specifies the duration Readline will wait for a character when
          reading an ambiguous key sequence (one that can form a
          complete key sequence using the input read so far, or can take
          additional input to complete a longer key sequence).  If no
          input is received within the timeout, Readline will use the
          shorter but complete key sequence.  Readline uses this value
          to determine whether or not input is available on the current
          input source ('rl_instream' by default).  The value is
          specified in milliseconds, so a value of 1000 means that
          Readline will wait one second for additional input.  If this
          variable is set to a value less than or equal to zero, or to a
          non-numeric value, Readline will wait until another key is
          pressed to decide which key sequence to complete.  The default
          value is '500'.

     'mark-directories'
          If set to 'on', completed directory names have a slash
          appended.  The default is 'on'.

     'mark-modified-lines'
          This variable, when set to 'on', causes Readline to display an
          asterisk ('*') at the start of history lines which have been
          modified.  This variable is 'off' by default.

     'mark-symlinked-directories'
          If set to 'on', completed names which are symbolic links to
          directories have a slash appended (subject to the value of
          'mark-directories').  The default is 'off'.

     'match-hidden-files'
          This variable, when set to 'on', causes Readline to match
          files whose names begin with a '.' (hidden files) when
          performing filename completion.  If set to 'off', the leading
          '.' must be supplied by the user in the filename to be
          completed.  This variable is 'on' by default.

     'menu-complete-display-prefix'
          If set to 'on', menu completion displays the common prefix of
          the list of possible completions (which may be empty) before
          cycling through the list.  The default is 'off'.

     'output-meta'
          If set to 'on', Readline will display characters with the
          eighth bit set directly rather than as a meta-prefixed escape
          sequence.  The default is 'off', but Readline will set it to
          'on' if the locale contains eight-bit characters.

     'page-completions'
          If set to 'on', Readline uses an internal 'more'-like pager to
          display a screenful of possible completions at a time.  This
          variable is 'on' by default.

     'print-completions-horizontally'
          If set to 'on', Readline will display completions with matches
          sorted horizontally in alphabetical order, rather than down
          the screen.  The default is 'off'.

     'revert-all-at-newline'
          If set to 'on', Readline will undo all changes to history
          lines before returning when 'accept-line' is executed.  By
          default, history lines may be modified and retain individual
          undo lists across calls to 'readline'.  The default is 'off'.

     'show-all-if-ambiguous'
          This alters the default behavior of the completion functions.
          If set to 'on', words which have more than one possible
          completion cause the matches to be listed immediately instead
          of ringing the bell.  The default value is 'off'.

     'show-all-if-unmodified'
          This alters the default behavior of the completion functions
          in a fashion similar to SHOW-ALL-IF-AMBIGUOUS.  If set to
          'on', words which have more than one possible completion
          without any possible partial completion (the possible
          completions don't share a common prefix) cause the matches to
          be listed immediately instead of ringing the bell.  The
          default value is 'off'.

     'show-mode-in-prompt'
          If set to 'on', add a string to the beginning of the prompt
          indicating the editing mode: emacs, vi command, or vi
          insertion.  The mode strings are user-settable (e.g.,
          EMACS-MODE-STRING).  The default value is 'off'.

     'skip-completed-text'
          If set to 'on', this alters the default completion behavior
          when inserting a single match into the line.  It's only active
          when performing completion in the middle of a word.  If
          enabled, readline does not insert characters from the
          completion that match characters after point in the word being
          completed, so portions of the word following the cursor are
          not duplicated.  For instance, if this is enabled, attempting
          completion when the cursor is after the 'e' in 'Makefile' will
          result in 'Makefile' rather than 'Makefilefile', assuming
          there is a single possible completion.  The default value is
          'off'.

     'vi-cmd-mode-string'
          If the SHOW-MODE-IN-PROMPT variable is enabled, this string is
          displayed immediately before the last line of the primary
          prompt when vi editing mode is active and in command mode.
          The value is expanded like a key binding, so the standard set
          of meta- and control prefixes and backslash escape sequences
          is available.  Use the '\1' and '\2' escapes to begin and end
          sequences of non-printing characters, which can be used to
          embed a terminal control sequence into the mode string.  The
          default is '(cmd)'.

     'vi-ins-mode-string'
          If the SHOW-MODE-IN-PROMPT variable is enabled, this string is
          displayed immediately before the last line of the primary
          prompt when vi editing mode is active and in insertion mode.
          The value is expanded like a key binding, so the standard set
          of meta- and control prefixes and backslash escape sequences
          is available.  Use the '\1' and '\2' escapes to begin and end
          sequences of non-printing characters, which can be used to
          embed a terminal control sequence into the mode string.  The
          default is '(ins)'.

     'visible-stats'
          If set to 'on', a character denoting a file's type is appended
          to the filename when listing possible completions.  The
          default is 'off'.

Key Bindings
     The syntax for controlling key bindings in the init file is simple.
     First you need to find the name of the command that you want to
     change.  The following sections contain tables of the command name,
     the default keybinding, if any, and a short description of what the
     command does.

     Once you know the name of the command, simply place on a line in
     the init file the name of the key you wish to bind the command to,
     a colon, and then the name of the command.  There can be no space
     between the key name and the colon - that will be interpreted as
     part of the key name.  The name of the key can be expressed in
     different ways, depending on what you find most comfortable.

     In addition to command names, readline allows keys to be bound to a
     string that is inserted when the key is pressed (a MACRO).

     KEYNAME: FUNCTION-NAME or MACRO
          KEYNAME is the name of a key spelled out in English.  For
          example:
               Control-u: universal-argument
               Meta-Rubout: backward-kill-word
               Control-o: "> output"

          In the example above, 'C-u' is bound to the function
          'universal-argument', 'M-DEL' is bound to the function
          'backward-kill-word', and 'C-o' is bound to run the macro
          expressed on the right hand side (that is, to insert the text
          '> output' into the line).

          A number of symbolic character names are recognized while
          processing this key binding syntax: DEL, ESC, ESCAPE, LFD,
          NEWLINE, RET, RETURN, RUBOUT, SPACE, SPC, and TAB.

     "KEYSEQ": FUNCTION-NAME or MACRO
          KEYSEQ differs from KEYNAME above in that strings denoting an
          entire key sequence can be specified, by placing the key
          sequence in double quotes.  Some GNU Emacs style key escapes
          can be used, as in the following example, but the special
          character names are not recognized.

               "\C-u": universal-argument
               "\C-x\C-r": re-read-init-file
               "\e[11~": "Function Key 1"

          In the above example, 'C-u' is again bound to the function
          'universal-argument' (just as it was in the first example),
          ''C-x' 'C-r'' is bound to the function 're-read-init-file',
          and '<ESC> <[> <1> <1> <~>' is bound to insert the text
          'Function Key 1'.

     The following GNU Emacs style escape sequences are available when
     specifying key sequences:

     '\C-'
          control prefix
     '\M-'
          meta prefix
     '\e'
          an escape character
     '\\'
          backslash
     '\"'
          <">, a double quotation mark
     '\''
          <'>, a single quote or apostrophe

     In addition to the GNU Emacs style escape sequences, a second set
     of backslash escapes is available:

     '\a'
          alert (bell)
     '\b'
          backspace
     '\d'
          delete
     '\f'
          form feed
     '\n'
          newline
     '\r'
          carriage return
     '\t'
          horizontal tab
     '\v'
          vertical tab
     '\NNN'
          the eight-bit character whose value is the octal value NNN
          (one to three digits)
     '\xHH'
          the eight-bit character whose value is the hexadecimal value
          HH (one or two hex digits)

     When entering the text of a macro, single or double quotes must be
     used to indicate a macro definition.  Unquoted text is assumed to
     be a function name.  In the macro body, the backslash escapes
     described above are expanded.  Backslash will quote any other
     character in the macro text, including '"' and '''.  For example,
     the following binding will make ''C-x' \' insert a single '\' into
     the line:
          "\C-x\\": "\\"


File: gdb.info,  Node: Conditional Init Constructs,  Next: Sample Init File,  Prev: Readline Init File Syntax,  Up: Readline Init File

32.3.2 Conditional Init Constructs
----------------------------------

Readline implements a facility similar in spirit to the conditional
compilation features of the C preprocessor which allows key bindings and
variable settings to be performed as the result of tests.  There are
four parser directives used.

'$if'
     The '$if' construct allows bindings to be made based on the editing
     mode, the terminal being used, or the application using Readline.
     The text of the test, after any comparison operator, extends to the
     end of the line; unless otherwise noted, no characters are required
     to isolate it.

     'mode'
          The 'mode=' form of the '$if' directive is used to test
          whether Readline is in 'emacs' or 'vi' mode.  This may be used
          in conjunction with the 'set keymap' command, for instance, to
          set bindings in the 'emacs-standard' and 'emacs-ctlx' keymaps
          only if Readline is starting out in 'emacs' mode.

     'term'
          The 'term=' form may be used to include terminal-specific key
          bindings, perhaps to bind the key sequences output by the
          terminal's function keys.  The word on the right side of the
          '=' is tested against both the full name of the terminal and
          the portion of the terminal name before the first '-'.  This
          allows 'sun' to match both 'sun' and 'sun-cmd', for instance.

     'version'
          The 'version' test may be used to perform comparisons against
          specific Readline versions.  The 'version' expands to the
          current Readline version.  The set of comparison operators
          includes '=' (and '=='), '!=', '<=', '>=', '<', and '>'.  The
          version number supplied on the right side of the operator
          consists of a major version number, an optional decimal point,
          and an optional minor version (e.g., '7.1').  If the minor
          version is omitted, it is assumed to be '0'.  The operator may
          be separated from the string 'version' and from the version
          number argument by whitespace.  The following example sets a
          variable if the Readline version being used is 7.0 or newer:
               $if version >= 7.0
               set show-mode-in-prompt on
               $endif

     'application'
          The APPLICATION construct is used to include
          application-specific settings.  Each program using the
          Readline library sets the APPLICATION NAME, and you can test
          for a particular value.  This could be used to bind key
          sequences to functions useful for a specific program.  For
          instance, the following command adds a key sequence that
          quotes the current or previous word in Bash:
               $if Bash
               # Quote the current or previous word
               "\C-xq": "\eb\"\ef\""
               $endif

     'variable'
          The VARIABLE construct provides simple equality tests for
          Readline variables and values.  The permitted comparison
          operators are '=', '==', and '!='.  The variable name must be
          separated from the comparison operator by whitespace; the
          operator may be separated from the value on the right hand
          side by whitespace.  Both string and boolean variables may be
          tested.  Boolean variables must be tested against the values
          ON and OFF.  The following example is equivalent to the
          'mode=emacs' test described above:
               $if editing-mode == emacs
               set show-mode-in-prompt on
               $endif

'$endif'
     This command, as seen in the previous example, terminates an '$if'
     command.

'$else'
     Commands in this branch of the '$if' directive are executed if the
     test fails.

'$include'
     This directive takes a single filename as an argument and reads
     commands and bindings from that file.  For example, the following
     directive reads from '/etc/inputrc':
          $include /etc/inputrc


File: gdb.info,  Node: Sample Init File,  Prev: Conditional Init Constructs,  Up: Readline Init File

32.3.3 Sample Init File
-----------------------

Here is an example of an INPUTRC file.  This illustrates key binding,
variable assignment, and conditional syntax.

     # This file controls the behaviour of line input editing for
     # programs that use the GNU Readline library.  Existing
     # programs include FTP, Bash, and GDB.
     #
     # You can re-read the inputrc file with C-x C-r.
     # Lines beginning with '#' are comments.
     #
     # First, include any system-wide bindings and variable
     # assignments from /etc/Inputrc
     $include /etc/Inputrc

     #
     # Set various bindings for emacs mode.

     set editing-mode emacs

     $if mode=emacs

     Meta-Control-h:	backward-kill-word	Text after the function name is ignored

     #
     # Arrow keys in keypad mode
     #
     #"\M-OD":        backward-char
     #"\M-OC":        forward-char
     #"\M-OA":        previous-history
     #"\M-OB":        next-history
     #
     # Arrow keys in ANSI mode
     #
     "\M-[D":        backward-char
     "\M-[C":        forward-char
     "\M-[A":        previous-history
     "\M-[B":        next-history
     #
     # Arrow keys in 8 bit keypad mode
     #
     #"\M-\C-OD":       backward-char
     #"\M-\C-OC":       forward-char
     #"\M-\C-OA":       previous-history
     #"\M-\C-OB":       next-history
     #
     # Arrow keys in 8 bit ANSI mode
     #
     #"\M-\C-[D":       backward-char
     #"\M-\C-[C":       forward-char
     #"\M-\C-[A":       previous-history
     #"\M-\C-[B":       next-history

     C-q: quoted-insert

     $endif

     # An old-style binding.  This happens to be the default.
     TAB: complete

     # Macros that are convenient for shell interaction
     $if Bash
     # edit the path
     "\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f"
     # prepare to type a quoted word --
     # insert open and close double quotes
     # and move to just after the open quote
     "\C-x\"": "\"\"\C-b"
     # insert a backslash (testing backslash escapes
     # in sequences and macros)
     "\C-x\\": "\\"
     # Quote the current or previous word
     "\C-xq": "\eb\"\ef\""
     # Add a binding to refresh the line, which is unbound
     "\C-xr": redraw-current-line
     # Edit variable on current line.
     "\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="
     $endif

     # use a visible bell if one is available
     set bell-style visible

     # don't strip characters to 7 bits when reading
     set input-meta on

     # allow iso-latin1 characters to be inserted rather
     # than converted to prefix-meta sequences
     set convert-meta off

     # display characters with the eighth bit set directly
     # rather than as meta-prefixed characters
     set output-meta on

     # if there are 150 or more possible completions for a word,
     # ask whether or not the user wants to see all of them
     set completion-query-items 150

     # For FTP
     $if Ftp
     "\C-xg": "get \M-?"
     "\C-xt": "put \M-?"
     "\M-.": yank-last-arg
     $endif


File: gdb.info,  Node: Bindable Readline Commands,  Next: Readline vi Mode,  Prev: Readline Init File,  Up: Command Line Editing

32.4 Bindable Readline Commands
===============================

* Menu:

* Commands For Moving::		Moving about the line.
* Commands For History::	Getting at previous lines.
* Commands For Text::		Commands for changing text.
* Commands For Killing::	Commands for killing and yanking.
* Numeric Arguments::		Specifying numeric arguments, repeat counts.
* Commands For Completion::	Getting Readline to do the typing for you.
* Keyboard Macros::		Saving and re-executing typed characters
* Miscellaneous Commands::	Other miscellaneous commands.

This section describes Readline commands that may be bound to key
sequences.  Command names without an accompanying key sequence are
unbound by default.

   In the following descriptions, "point" refers to the current cursor
position, and "mark" refers to a cursor position saved by the 'set-mark'
command.  The text between the point and mark is referred to as the
"region".


File: gdb.info,  Node: Commands For Moving,  Next: Commands For History,  Up: Bindable Readline Commands

32.4.1 Commands For Moving
--------------------------

'beginning-of-line (C-a)'
     Move to the start of the current line.

'end-of-line (C-e)'
     Move to the end of the line.

'forward-char (C-f)'
     Move forward a character.

'backward-char (C-b)'
     Move back a character.

'forward-word (M-f)'
     Move forward to the end of the next word.  Words are composed of
     letters and digits.

'backward-word (M-b)'
     Move back to the start of the current or previous word.  Words are
     composed of letters and digits.

'previous-screen-line ()'
     Attempt to move point to the same physical screen column on the
     previous physical screen line.  This will not have the desired
     effect if the current Readline line does not take up more than one
     physical line or if point is not greater than the length of the
     prompt plus the screen width.

'next-screen-line ()'
     Attempt to move point to the same physical screen column on the
     next physical screen line.  This will not have the desired effect
     if the current Readline line does not take up more than one
     physical line or if the length of the current Readline line is not
     greater than the length of the prompt plus the screen width.

'clear-display (M-C-l)'
     Clear the screen and, if possible, the terminal's scrollback
     buffer, then redraw the current line, leaving the current line at
     the top of the screen.

'clear-screen (C-l)'
     Clear the screen, then redraw the current line, leaving the current
     line at the top of the screen.

'redraw-current-line ()'
     Refresh the current line.  By default, this is unbound.


File: gdb.info,  Node: Commands For History,  Next: Commands For Text,  Prev: Commands For Moving,  Up: Bindable Readline Commands

32.4.2 Commands For Manipulating The History
--------------------------------------------

'accept-line (Newline or Return)'
     Accept the line regardless of where the cursor is.  If this line is
     non-empty, it may be added to the history list for future recall
     with 'add_history()'.  If this line is a modified history line, the
     history line is restored to its original state.

'previous-history (C-p)'
     Move 'back' through the history list, fetching the previous
     command.

'next-history (C-n)'
     Move 'forward' through the history list, fetching the next command.

'beginning-of-history (M-<)'
     Move to the first line in the history.

'end-of-history (M->)'
     Move to the end of the input history, i.e., the line currently
     being entered.

'reverse-search-history (C-r)'
     Search backward starting at the current line and moving 'up'
     through the history as necessary.  This is an incremental search.
     This command sets the region to the matched text and activates the
     mark.

'forward-search-history (C-s)'
     Search forward starting at the current line and moving 'down'
     through the history as necessary.  This is an incremental search.
     This command sets the region to the matched text and activates the
     mark.

'non-incremental-reverse-search-history (M-p)'
     Search backward starting at the current line and moving 'up'
     through the history as necessary using a non-incremental search for
     a string supplied by the user.  The search string may match
     anywhere in a history line.

'non-incremental-forward-search-history (M-n)'
     Search forward starting at the current line and moving 'down'
     through the history as necessary using a non-incremental search for
     a string supplied by the user.  The search string may match
     anywhere in a history line.

'history-search-forward ()'
     Search forward through the history for the string of characters
     between the start of the current line and the point.  The search
     string must match at the beginning of a history line.  This is a
     non-incremental search.  By default, this command is unbound.

'history-search-backward ()'
     Search backward through the history for the string of characters
     between the start of the current line and the point.  The search
     string must match at the beginning of a history line.  This is a
     non-incremental search.  By default, this command is unbound.

'history-substring-search-forward ()'
     Search forward through the history for the string of characters
     between the start of the current line and the point.  The search
     string may match anywhere in a history line.  This is a
     non-incremental search.  By default, this command is unbound.

'history-substring-search-backward ()'
     Search backward through the history for the string of characters
     between the start of the current line and the point.  The search
     string may match anywhere in a history line.  This is a
     non-incremental search.  By default, this command is unbound.

'yank-nth-arg (M-C-y)'
     Insert the first argument to the previous command (usually the
     second word on the previous line) at point.  With an argument N,
     insert the Nth word from the previous command (the words in the
     previous command begin with word 0).  A negative argument inserts
     the Nth word from the end of the previous command.  Once the
     argument N is computed, the argument is extracted as if the '!N'
     history expansion had been specified.

'yank-last-arg (M-. or M-_)'
     Insert last argument to the previous command (the last word of the
     previous history entry).  With a numeric argument, behave exactly
     like 'yank-nth-arg'.  Successive calls to 'yank-last-arg' move back
     through the history list, inserting the last word (or the word
     specified by the argument to the first call) of each line in turn.
     Any numeric argument supplied to these successive calls determines
     the direction to move through the history.  A negative argument
     switches the direction through the history (back or forward).  The
     history expansion facilities are used to extract the last argument,
     as if the '!$' history expansion had been specified.

'operate-and-get-next (C-o)'
     Accept the current line for return to the calling application as if
     a newline had been entered, and fetch the next line relative to the
     current line from the history for editing.  A numeric argument, if
     supplied, specifies the history entry to use instead of the current
     line.


File: gdb.info,  Node: Commands For Text,  Next: Commands For Killing,  Prev: Commands For History,  Up: Bindable Readline Commands

32.4.3 Commands For Changing Text
---------------------------------

'end-of-file (usually C-d)'
     The character indicating end-of-file as set, for example, by
     'stty'.  If this character is read when there are no characters on
     the line, and point is at the beginning of the line, Readline
     interprets it as the end of input and returns EOF.

'delete-char (C-d)'
     Delete the character at point.  If this function is bound to the
     same character as the tty EOF character, as 'C-d' commonly is, see
     above for the effects.

'backward-delete-char (Rubout)'
     Delete the character behind the cursor.  A numeric argument means
     to kill the characters instead of deleting them.

'forward-backward-delete-char ()'
     Delete the character under the cursor, unless the cursor is at the
     end of the line, in which case the character behind the cursor is
     deleted.  By default, this is not bound to a key.

'quoted-insert (C-q or C-v)'
     Add the next character typed to the line verbatim.  This is how to
     insert key sequences like 'C-q', for example.

'tab-insert (M-<TAB>)'
     Insert a tab character.

'self-insert (a, b, A, 1, !, ...)'
     Insert yourself.

'bracketed-paste-begin ()'
     This function is intended to be bound to the "bracketed paste"
     escape sequence sent by some terminals, and such a binding is
     assigned by default.  It allows Readline to insert the pasted text
     as a single unit without treating each character as if it had been
     read from the keyboard.  The characters are inserted as if each one
     was bound to 'self-insert' instead of executing any editing
     commands.

     Bracketed paste sets the region (the characters between point and
     the mark) to the inserted text.  It uses the concept of an _active
     mark_: when the mark is active, Readline redisplay uses the
     terminal's standout mode to denote the region.

'transpose-chars (C-t)'
     Drag the character before the cursor forward over the character at
     the cursor, moving the cursor forward as well.  If the insertion
     point is at the end of the line, then this transposes the last two
     characters of the line.  Negative arguments have no effect.

'transpose-words (M-t)'
     Drag the word before point past the word after point, moving point
     past that word as well.  If the insertion point is at the end of
     the line, this transposes the last two words on the line.

'upcase-word (M-u)'
     Uppercase the current (or following) word.  With a negative
     argument, uppercase the previous word, but do not move the cursor.

'downcase-word (M-l)'
     Lowercase the current (or following) word.  With a negative
     argument, lowercase the previous word, but do not move the cursor.

'capitalize-word (M-c)'
     Capitalize the current (or following) word.  With a negative
     argument, capitalize the previous word, but do not move the cursor.

'overwrite-mode ()'
     Toggle overwrite mode.  With an explicit positive numeric argument,
     switches to overwrite mode.  With an explicit non-positive numeric
     argument, switches to insert mode.  This command affects only
     'emacs' mode; 'vi' mode does overwrite differently.  Each call to
     'readline()' starts in insert mode.

     In overwrite mode, characters bound to 'self-insert' replace the
     text at point rather than pushing the text to the right.
     Characters bound to 'backward-delete-char' replace the character
     before point with a space.

     By default, this command is unbound.


File: gdb.info,  Node: Commands For Killing,  Next: Numeric Arguments,  Prev: Commands For Text,  Up: Bindable Readline Commands

32.4.4 Killing And Yanking
--------------------------

'kill-line (C-k)'
     Kill the text from point to the end of the line.  With a negative
     numeric argument, kill backward from the cursor to the beginning of
     the current line.

'backward-kill-line (C-x Rubout)'
     Kill backward from the cursor to the beginning of the current line.
     With a negative numeric argument, kill forward from the cursor to
     the end of the current line.

'unix-line-discard (C-u)'
     Kill backward from the cursor to the beginning of the current line.

'kill-whole-line ()'
     Kill all characters on the current line, no matter where point is.
     By default, this is unbound.

'kill-word (M-d)'
     Kill from point to the end of the current word, or if between
     words, to the end of the next word.  Word boundaries are the same
     as 'forward-word'.

'backward-kill-word (M-<DEL>)'
     Kill the word behind point.  Word boundaries are the same as
     'backward-word'.

'shell-transpose-words (M-C-t)'
     Drag the word before point past the word after point, moving point
     past that word as well.  If the insertion point is at the end of
     the line, this transposes the last two words on the line.  Word
     boundaries are the same as 'shell-forward-word' and
     'shell-backward-word'.

'unix-word-rubout (C-w)'
     Kill the word behind point, using white space as a word boundary.
     The killed text is saved on the kill-ring.

'unix-filename-rubout ()'
     Kill the word behind point, using white space and the slash
     character as the word boundaries.  The killed text is saved on the
     kill-ring.

'delete-horizontal-space ()'
     Delete all spaces and tabs around point.  By default, this is
     unbound.

'kill-region ()'
     Kill the text in the current region.  By default, this command is
     unbound.

'copy-region-as-kill ()'
     Copy the text in the region to the kill buffer, so it can be yanked
     right away.  By default, this command is unbound.

'copy-backward-word ()'
     Copy the word before point to the kill buffer.  The word boundaries
     are the same as 'backward-word'.  By default, this command is
     unbound.

'copy-forward-word ()'
     Copy the word following point to the kill buffer.  The word
     boundaries are the same as 'forward-word'.  By default, this
     command is unbound.

'yank (C-y)'
     Yank the top of the kill ring into the buffer at point.

'yank-pop (M-y)'
     Rotate the kill-ring, and yank the new top.  You can only do this
     if the prior command is 'yank' or 'yank-pop'.

