binutils-gdb/gdb/mi/gdbmi.texinfo

@c  \input texinfo   @c -*-texinfo-*-
@c  @c %**start of header
@c  @setfilename gdbmi.info
@c  @settitle GDB/MI Machine Interface
@c  @setchapternewpage off
@c  @c %**end of header

@c  @ifinfo
@c  This file documents GDB/MI, a Machine Interface to GDB.

@c  Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
@c  Contributed by Cygnus Solutions.

@c  Permission is granted to copy, distribute and/or modify this document
@c  under the terms of the GNU Free Documentation License, Version 1.1 or
@c  any later version published by the Free Software Foundation; with no
@c  Invariant Sections, with the Front-Cover Texts being ``A GNU Manual,''
@c  and with the Back-Cover Texts as in (a) below.

@c  (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
@c  this GNU Manual, like GNU software.  Copies published by the Free
@c  Software Foundation raise funds for GNU development.''
@c  @end ifinfo

@c  @c  This title page illustrates only one of the
@c  @c  two methods of forming a title page.

@c  @titlepage
@c  @title GDB/MI
@c  @subtitle Version 0.3
@c  @subtitle Apr 2001
@c  @author Andrew Cagney, Fernando Nasser and Elena Zannoni

@c  @c  The following two commands
@c  @c  start the copyright page.
@c  @page
@c  @vskip 0pt plus 1filll

@c  Copyright @copyright{} 2000, 2001, 2002 Free Software Foundation, Inc.

@c  Permission is granted to copy, distribute and/or modify this document
@c  under the terms of the GNU Free Documentation License, Version 1.1 or
@c  any later version published by the Free Software Foundation; with no
@c  Invariant Sections, with the Front-Cover texts being ``A GNU Manual,''
@c  and with the Back-Cover Texts as in (a) below.

@c  (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
@c  this GNU Manual, like GNU software.  Copies published by the Free
@c  Software Foundation raise funds for GNU development.''
@c  @end titlepage

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% CHAPTER %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI
@chapter The @sc{gdb/mi} Interface

@unnumberedsec Function and Purpose

@cindex @sc{gdb/mi}, its purpose
@sc{gdb/mi} is a line based machine oriented text interface to @value{GDBN}.  It is
specifically intended to support the development of systems which use
the debugger as just one small component of a larger system.

This chapter is a specification of the @sc{gdb/mi} interface.  It is written
in the form of a reference manual.

Note that @sc{gdb/mi} is still under construction, so some of the
features described below are incomplete and subject to change.

@unnumberedsec Notation and Terminology

@cindex notational conventions, for @sc{gdb/mi}
This chapter uses the following notation:

@itemize @bullet
@item
@code{|} separates two alternatives.

@item
@code{[ @var{something} ]} indicates that @var{something} is optional:
it may or may not be given.

@item
@code{( @var{group} )*} means that @var{group} inside the parentheses
may repeat zero or more times.

@item
@code{( @var{group} )+} means that @var{group} inside the parentheses
may repeat one or more times.

@item
@code{"@var{string}"} means a literal @var{string}.
@end itemize

@ignore
@heading Dependencies
@end ignore

@heading Acknowledgments

In alphabetic order: Andrew Cagney, Fernando Nasser, Stan Shebs and
Elena Zannoni.

@menu
* GDB/MI Command Syntax::
* GDB/MI Compatibility with CLI::
* GDB/MI Output Records::
* GDB/MI Command Description Format::
* GDB/MI Breakpoint Table Commands::
* GDB/MI Data Manipulation::
* GDB/MI Program Control::
* GDB/MI Miscellaneous Commands::
@ignore
* GDB/MI Kod Commands::
* GDB/MI Memory Overlay Commands::
* GDB/MI Signal Handling Commands::
@end ignore
* GDB/MI Stack Manipulation::
* GDB/MI Symbol Query::
* GDB/MI Target Manipulation::
* GDB/MI Thread Commands::
* GDB/MI Tracepoint Commands::
* GDB/MI Variable Objects::
@end menu

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Command Syntax
@section @sc{gdb/mi} Command Syntax

@menu
* GDB/MI Input Syntax::
* GDB/MI Output Syntax::
* GDB/MI Simple Examples::
@end menu

@node GDB/MI Input Syntax
@subsection @sc{gdb/mi} Input Syntax

@cindex input syntax for @sc{gdb/mi}
@cindex @sc{gdb/mi}, input syntax
@table @code
@item @var{command} @expansion{}
@code{@var{cli-command} | @var{mi-command}}

@item @var{cli-command} @expansion{}
@code{[ @var{token} ] @var{cli-command} @var{nl}}, where
@var{cli-command} is any existing @value{GDBN} CLI command.

@item @var{mi-command} @expansion{}
@code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )*
@code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}}

@item @var{token} @expansion{}
"any sequence of digits"

@item @var{option} @expansion{}
@code{"-" @var{parameter} [ " " @var{parameter} ]}

@item @var{parameter} @expansion{}
@code{@var{non-blank-sequence} | @var{c-string}}

@item @var{operation} @expansion{}
@emph{any of the operations described in this chapter}

@item @var{non-blank-sequence} @expansion{}
@emph{anything, provided it doesn't contain special characters such as
"-", @var{nl}, """ and of course " "}

@item @var{c-string} @expansion{}
@code{""" @var{seven-bit-iso-c-string-content} """}

@item @var{nl} @expansion{}
@code{CR | CR-LF}
@end table

@noindent
Notes:

@itemize @bullet
@item
The CLI commands are still handled by the @sc{mi} interpreter; their
output is described below.

@item
The @code{@var{token}}, when present, is passed back when the command
finishes.

@item
Some @sc{mi} commands accept optional arguments as part of the parameter
list.  Each option is identified by a leading @samp{-} (dash) and may be
followed by an optional argument parameter.  Options occur first in the
parameter list and can be delimited from normal parameters using
@samp{--} (this is useful when some parameters begin with a dash).
@end itemize

Pragmatics:

@itemize @bullet
@item
We want easy access to the existing CLI syntax (for debugging).

@item
We want it to be easy to spot a @sc{mi} operation.
@end itemize

@node GDB/MI Output Syntax
@subsection @sc{gdb/mi} Output Syntax

@cindex output syntax of @sc{gdb/mi}
@cindex @sc{gdb/mi}, output syntax
The output from @sc{gdb/mi} consists of zero or more out-of-band records
followed, optionally, by a single result record.  This result record
is for the most recent command.  The sequence of output records is
terminated by @samp{(@value{GDBP})}.

If an input command was prefixed with a @code{@var{token}} then the
corresponding output for that command will also be prefixed by that same
@var{token}.

@table @code
@item @var{output} @expansion{}
@code{( @var{out-of-band-record} )* [ @var{result-record} ] "(gdb)" @var{nl}}

@item @var{result-record} @expansion{}
@code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}}

@item @var{out-of-band-record} @expansion{}
@code{@var{async-record} | @var{stream-record}}

@item @var{async-record} @expansion{}
@code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}}

@item @var{exec-async-output} @expansion{}
@code{[ @var{token} ] "*" @var{async-output}}

@item @var{status-async-output} @expansion{}
@code{[ @var{token} ] "+" @var{async-output}}

@item @var{notify-async-output} @expansion{}
@code{[ @var{token} ] "=" @var{async-output}}

@item @var{async-output} @expansion{}
@code{@var{async-class} ( "," @var{result} )* @var{nl}}

@item @var{result-class} @expansion{}
@code{"done" | "running" | "connected" | "error" | "exit"}

@item @var{async-class} @expansion{}
@code{"stopped" | @var{others}} (where @var{others} will be added
depending on the needs---this is still in development).

@item @var{result} @expansion{}
@code{ @var{variable} "=" @var{value}}

@item @var{variable} @expansion{}
@code{ @var{string} }

@item @var{value} @expansion{}
@code{ @var{const} | @var{tuple} | @var{list} }

@item @var{const} @expansion{}
@code{@var{c-string}}

@item @var{tuple} @expansion{}
@code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" }

@item @var{list} @expansion{}
@code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "["
@var{result} ( "," @var{result} )* "]" }

@item @var{stream-record} @expansion{}
@code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}}

@item @var{console-stream-output} @expansion{}
@code{"~" @var{c-string}}

@item @var{target-stream-output} @expansion{}
@code{"@@" @var{c-string}}

@item @var{log-stream-output} @expansion{}
@code{"&" @var{c-string}}

@item @var{nl} @expansion{}
@code{CR | CR-LF}

@item @var{token} @expansion{}
@emph{any sequence of digits}.
@end table

@noindent
Notes:

@itemize @bullet
@item
All output sequences end in a single line containing a period.

@item
The @code{@var{token}} is from the corresponding request.  If an execution
command is interrupted by the @samp{-exec-interrupt} command, the
@var{token} associated with the @samp{*stopped} message is the one of the
original execution command, not the one of the interrupt command.

@item
@cindex status output in @sc{gdb/mi}
@var{status-async-output} contains on-going status information about the
progress of a slow operation.  It can be discarded.  All status output is
prefixed by @samp{+}.

@item
@cindex async output in @sc{gdb/mi}
@var{exec-async-output} contains asynchronous state change on the target
(stopped, started, disappeared).  All async output is prefixed by
@samp{*}.

@item
@cindex notify output in @sc{gdb/mi}
@var{notify-async-output} contains supplementary information that the
client should handle (e.g., a new breakpoint information).  All notify
output is prefixed by @samp{=}.

@item
@cindex console output in @sc{gdb/mi}
@var{console-stream-output} is output that should be displayed as is in the
console.  It is the textual response to a CLI command.  All the console
output is prefixed by @samp{~}.

@item
@cindex target output in @sc{gdb/mi}
@var{target-stream-output} is the output produced by the target program.
All the target output is prefixed by @samp{@@}.

@item
@cindex log output in @sc{gdb/mi}
@var{log-stream-output} is output text coming from @value{GDBN}'s internals, for
instance messages that should be displayed as part of an error log.  All
the log output is prefixed by @samp{&}.

@item
@cindex list output in @sc{gdb/mi}
New @sc{gdb/mi} commands should only output @var{lists} containing
@var{values}.


@end itemize

@xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more
details about the various output records.

@node GDB/MI Simple Examples
@subsection Simple Examples of @sc{gdb/mi} Interaction
@cindex @sc{gdb/mi}, simple examples

This subsection presents several simple examples of interaction using
the @sc{gdb/mi} interface.  In these examples, @samp{->} means that the
following line is passed to @sc{gdb/mi} as input, while @samp{<-} means
the output received from @sc{gdb/mi}.

@subsubheading Target Stop
@c Ummm... There is no "-stop" command. This assumes async, no?
Here's an example of stopping the inferior process:

@example
-> -stop
<- (@value{GDBP})
@end example

@noindent
and later:

@example
<- *stop,reason="stop",address="0x123",source="a.c:123"
<- (@value{GDBP})
@end example

@subsubheading Simple CLI Command

Here's an example of a simple CLI command being passed through
@sc{gdb/mi} and on to the CLI.

@example
-> print 1+2
<- &"print 1+2\n"
<- ~"$1 = 3\n"
<- ^done
<- (@value{GDBP})
@end example

@subsubheading Command With Side Effects

@example
-> -symbol-file xyz.exe
<- *breakpoint,nr="3",address="0x123",source="a.c:123"
<- (@value{GDBP})
@end example

@subsubheading A Bad Command

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

@example
-> -rubbish
<- ^error,msg="Undefined MI command: rubbish"
<- (@value{GDBP})
@end example

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Compatibility with CLI
@section @sc{gdb/mi} Compatibility with CLI

@cindex compatibility, @sc{gdb/mi} and CLI
@cindex @sc{gdb/mi}, compatibility with CLI
To help users familiar with @value{GDBN}'s existing CLI interface, @sc{gdb/mi}
accepts existing CLI commands.  As specified by the syntax, such
commands can be directly entered into the @sc{gdb/mi} interface and @value{GDBN} will
respond.

This mechanism is provided as an aid to developers of @sc{gdb/mi}
clients and not as a reliable interface into the CLI.  Since the command
is being interpreteted in an environment that assumes @sc{gdb/mi}
behaviour, the exact output of such commands is likely to end up being
an un-supported hybrid of @sc{gdb/mi} and CLI output.

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Output Records
@section @sc{gdb/mi} Output Records

@menu
* GDB/MI Result Records::
* GDB/MI Stream Records::
* GDB/MI Out-of-band Records::
@end menu

@node GDB/MI Result Records
@subsection @sc{gdb/mi} Result Records

@cindex result records in @sc{gdb/mi}
@cindex @sc{gdb/mi}, result records
In addition to a number of out-of-band notifications, the response to a
@sc{gdb/mi} command includes one of the following result indications:

@table @code
@findex ^done
@item "^done" [ "," @var{results} ]
The synchronous operation was successful, @code{@var{results}} are the return
values.

@item "^running"
@findex ^running
@c Is this one correct?  Should it be an out-of-band notification?
The asynchronous operation was successfully started.  The target is
running.

@item "^error" "," @var{c-string}
@findex ^error
The operation failed.  The @code{@var{c-string}} contains the corresponding
error message.
@end table

@node GDB/MI Stream Records
@subsection @sc{gdb/mi} Stream Records

@cindex @sc{gdb/mi}, stream records
@cindex stream records in @sc{gdb/mi}
@value{GDBN} 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 @sc{gdb/mi} interface using @dfn{stream records}.

Each stream record begins with a unique @dfn{prefix character} which
identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output
Syntax}).  In addition to the prefix, each stream record contains a
@code{@var{string-output}}.  This is either raw text (with an implicit new
line) or a quoted C string (which does not contain an implicit newline).

@table @code
@item "~" @var{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.

@item "@@" @var{string-output}
The target output stream contains any textual output from the running
target.

@item "&" @var{string-output}
The log stream contains debugging messages being produced by @value{GDBN}'s
internals.
@end table

@node GDB/MI Out-of-band Records
@subsection @sc{gdb/mi} Out-of-band Records

@cindex out-of-band records in @sc{gdb/mi}
@cindex @sc{gdb/mi}, out-of-band records
@dfn{Out-of-band} records are used to notify the @sc{gdb/mi} client of
additional changes that have occurred.  Those changes can either be a
consequence of @sc{gdb/mi} (e.g., a breakpoint modified) or a result of
target activity (e.g., target stopped).

The following is a preliminary list of possible out-of-band records.

@table @code
@item "*" "stop"
@end table


@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Command Description Format
@section @sc{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.

Note the the line breaks shown in the examples are here only for
readability.  They don't appear in the real output.
Also note that the commands with a non-available example (N.A.@:) are
not yet implemented.

@subheading Motivation

The motivation for this collection of commands.

@subheading Introduction

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

@subheading Commands

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

@subsubheading Synopsis

@example
 -command @var{args}@dots{}
@end example

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} CLI command.

@subsubheading Result

@subsubheading Out-of-band

@subsubheading Notes

@subsubheading Example


@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Breakpoint Table Commands
@section @sc{gdb/mi} Breakpoint table commands

@cindex breakpoint commands for @sc{gdb/mi}
@cindex @sc{gdb/mi}, breakpoint commands
This section documents @sc{gdb/mi} commands for manipulating
breakpoints.

@subheading The @code{-break-after} Command
@findex -break-after

@subsubheading Synopsis

@example
 -break-after @var{number} @var{count}
@end example

The breakpoint number @var{number} is not in effect until it has been
hit @var{count} times.  To see how this is reflected in the output of
the @samp{-break-list} command, see the description of the
@samp{-break-list} command below.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{ignore}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-insert main
^done,bkpt=@{number="1",addr="0x000100d0",file="hello.c",line="5"@}
(@value{GDBP})
-break-after 1 3
~
^done
(@value{GDBP})
-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",line="5",times="0",
ignore="3"@}]@}
(@value{GDBP})
@end smallexample

@ignore
@subheading The @code{-break-catch} Command
@findex -break-catch

@subheading The @code{-break-commands} Command
@findex -break-commands
@end ignore


@subheading The @code{-break-condition} Command
@findex -break-condition

@subsubheading Synopsis

@example
 -break-condition @var{number} @var{expr}
@end example

Breakpoint @var{number} will stop the program only if the condition in
@var{expr} is true.  The condition becomes part of the
@samp{-break-list} output (see the description of the @samp{-break-list}
command below).

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{condition}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-condition 1 1
^done
(@value{GDBP})
-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",line="5",cond="1",
times="0",ignore="3"@}]@}
(@value{GDBP})
@end smallexample

@subheading The @code{-break-delete} Command
@findex -break-delete

@subsubheading Synopsis

@example
 -break-delete ( @var{breakpoint} )+
@end example

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

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{delete}.

@subsubheading Example

@example
(@value{GDBP})
-break-delete 1
^done
(@value{GDBP})
-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=[]@}
(@value{GDBP})
@end example

@subheading The @code{-break-disable} Command
@findex -break-disable

@subsubheading Synopsis

@example
 -break-disable ( @var{breakpoint} )+
@end example

Disable the named @var{breakpoint}(s).  The field @samp{enabled} in the
break list is now set to @samp{n} for the named @var{breakpoint}(s).

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{disable}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-disable 2
^done
(@value{GDBP})
-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",line="5",times="0"@}]@}
(@value{GDBP})
@end smallexample

@subheading The @code{-break-enable} Command
@findex -break-enable

@subsubheading Synopsis

@example
 -break-enable ( @var{breakpoint} )+
@end example

Enable (previously disabled) @var{breakpoint}(s).

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{enable}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-enable 2
^done
(@value{GDBP})
-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",line="5",times="0"@}]@}
(@value{GDBP})
@end smallexample

@subheading The @code{-break-info} Command
@findex -break-info

@subsubheading Synopsis

@example
 -break-info @var{breakpoint}
@end example

@c REDUNDANT???
Get information about a single breakpoint.

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}.

@subsubheading Example
N.A.

@subheading The @code{-break-insert} Command
@findex -break-insert

@subsubheading Synopsis

@example
 -break-insert [ -t ] [ -h ] [ -r ]
    [ -c @var{condition} ] [ -i @var{ignore-count} ]
    [ -p @var{thread} ] [ @var{line} | @var{addr} ]
@end example

@noindent
If specified, @var{line}, can be one of:

@itemize @bullet
@item function
@c @item +offset
@c @item -offset
@c @item linenum
@item filename:linenum
@item filename:function
@item *address
@end itemize

The possible optional parameters of this command are:

@table @samp
@item -t
Insert a tempoary breakpoint.
@item -h
Insert a hardware breakpoint.
@item -c @var{condition}
Make the breakpoint conditional on @var{condition}.
@item -i @var{ignore-count}
Initialize the @var{ignore-count}.
@item -r
Insert a regular breakpoint in all the functions whose names match the
given regular expression.  Other flags are not applicable to regular
expresson.
@end table

@subsubheading Result

The result is in the form:

@example
 ^done,bkptno="@var{number}",func="@var{funcname}",
  file="@var{filename}",line="@var{lineno}"
@end example

@noindent
where @var{number} is the @value{GDBN} number for this breakpoint, @var{funcname}
is the name of the function where the breakpoint was inserted,
@var{filename} is the name of the source file which contains this
function, and @var{lineno} is the source line number within that file.

Note: this format is open to change.
@c An out-of-band breakpoint instead of part of the result?

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak},
@samp{hbreak}, @samp{thbreak}, and @samp{rbreak}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-insert main
^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@}
(@value{GDBP})
-break-insert -t foo
^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c",line="11"@}
(@value{GDBP})
-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",line="4",times="0"@},
bkpt=@{number="2",type="breakpoint",disp="del",enabled="y",
addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"@}]@}
(@value{GDBP})
-break-insert -r foo.*
~int foo(int, int);
^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c",line="11"@}
(@value{GDBP})
@end smallexample

@subheading The @code{-break-list} Command
@findex -break-list

@subsubheading Synopsis

@example
 -break-list
@end example

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

@table @samp
@item Number
number of the breakpoint
@item Type
type of the breakpoint: @samp{breakpoint} or @samp{watchpoint}
@item Disposition
should the breakpoint be deleted or disabled when it is hit: @samp{keep}
or @samp{nokeep}
@item Enabled
is the breakpoint enabled or no: @samp{y} or @samp{n}
@item Address
memory location at which the breakpoint is set
@item What
logical location of the breakpoint, expressed by function name, file
name, line number
@item Times
number of times the breakpoint has been hit
@end table

If there are no breakpoints or watchpoints, the @code{BreakpointTable}
@code{body} field is an empty list.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info break}.

@subsubheading Example

@smallexample
(@value{GDBP})
-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",times="0"@},
bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y",
addr="0x00010114",func="foo",file="hello.c",line="13",times="0"@}]@}
(@value{GDBP})
@end smallexample

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

@smallexample
(@value{GDBP})
-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=[]@}
(@value{GDBP})
@end smallexample

@subheading The @code{-break-watch} Command
@findex -break-watch

@subsubheading Synopsis

@example
 -break-watch [ -a | -r ]
@end example

Create a watchpoint.  With the @samp{-a} option it will create an
@dfn{access} watchpoint, i.e. a watchpoint that triggers either on a
read from or on a write to the memory location.  With the @samp{-r}
option, the watchpoint created is a @dfn{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.
@xref{Set Watchpoints, , Setting watchpoints}.

Note that @samp{-break-list} will report a single list of watchpoints and
breakpoints inserted.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and
@samp{rwatch}.

@subsubheading Example

Setting a watchpoint on a variable in the @code{main} function:

@smallexample
(@value{GDBP})
-break-watch x
^done,wpt=@{number="2",exp="x"@}
(@value{GDBP})
-exec-continue
^running
^done,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@},
value=@{old="-268439212",new="55"@},
frame=@{func="main",args=[],file="recursive2.c",line="5"@}
(@value{GDBP})
@end smallexample

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

@smallexample
(@value{GDBP})
-break-watch C
^done,wpt=@{number="5",exp="C"@}
(@value{GDBP})
-exec-continue
^running
^done,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",line="13"@}
(@value{GDBP})
-exec-continue
^running
^done,reason="watchpoint-scope",wpnum="5",
frame=@{func="callee3",args=[@{name="strarg",
value="0x11940 \"A string argument.\""@}],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"@}
(@value{GDBP})
@end smallexample

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

@smallexample
(@value{GDBP})
-break-watch C
^done,wpt=@{number="2",exp="C"@}
(@value{GDBP})
-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",line="8",times="1"@},
bkpt=@{number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="0"@}]@}
(@value{GDBP})
-exec-continue
^running
^done,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",line="13"@}
(@value{GDBP})
-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",line="8",times="1"@},
bkpt=@{number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="-5"@}]@}
(@value{GDBP})
-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",line="18"@}
(@value{GDBP})
-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",line="8",times="1"@}]@}
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Data Manipulation
@section @sc{gdb/mi} Data Manipulation

@cindex data manipulation, in @sc{gdb/mi}
@cindex @sc{gdb/mi}, data manipulation
This section describes the @sc{gdb/mi} commands that manipulate data:
examine memory and registers, evaluate expressions, etc.

@c REMOVED FROM THE INTERFACE.
@c @subheading -data-assign
@c Change the value of a program variable. Plenty of side effects.
@c @subsubheading GDB command
@c set variable
@c @subsubheading Example
@c N.A.

@subheading The @code{-data-disassemble} Command
@findex -data-disassemble

@subsubheading Synopsis

@example
 -data-disassemble
    [ -s @var{start-addr} -e @var{end-addr} ]
  | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ]
  -- @var{mode}
@end example

@noindent
Where:

@table @samp
@item @var{start-addr}
is the beginning address (or @code{$pc})
@item @var{end-addr}
is the end address
@item @var{filename}
is the name of the file to disassemble
@item @var{linenum}
is the line number to disassemble around
@item @var{lines}
is the the number of disassembly lines to be produced.  If it is -1,
the whole function will be disassembled, in case no @var{end-addr} is
specified.  If @var{end-addr} is specified as a non-zero value, and
@var{lines} is lower than the number of disassembly lines between
@var{start-addr} and @var{end-addr}, only @var{lines} lines are
displayed; if @var{lines} is higher than the number of lines between
@var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr}
are displayed.
@item @var{mode}
is either 0 (meaning only disassembly) or 1 (meaning mixed source and
disassembly).
@end table

@subsubheading Result

The output for each instruction is composed of four fields:

@itemize @bullet
@item Address
@item Func-name
@item Offset
@item Instruction
@end itemize

Note that whatever included in the instruction field, is not manipulated
directely by @sc{gdb/mi}, i.e. it is not possible to adjust its format.

@subsubheading @value{GDBN} Command

There's no direct mapping from this command to the CLI.

@subsubheading Example

Disassemble from the current value of @code{$pc} to @code{$pc + 20}:

@smallexample
(@value{GDBP})
-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>"@}]
(@value{GDBP})
@end smallexample

Disassemble the whole @code{main} function.  Line 32 is part of
@code{main}.

@smallexample
-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"@},
[@dots{}]
@{address="0x0001081c",func-name="main",offset="96",inst="ret "@},
@{address="0x00010820",func-name="main",offset="100",inst="restore "@}]
(@value{GDBP})
@end smallexample

Disassemble 3 instructions from the start of @code{main}:

@smallexample
(@value{GDBP})
-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"@}]
(@value{GDBP})
@end smallexample

Disassemble 3 instructions from the start of @code{main} in mixed mode:

@smallexample
(@value{GDBP})
-data-disassemble -f basics.c -l 32 -n 3 -- 1
^done,asm_insns=[
src_and_asm_line=@{line="31",
file="/kwikemart/marge/ezannoni/flathead-dev/devo/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="/kwikemart/marge/ezannoni/flathead-dev/devo/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"@}]@}]
(@value{GDBP})
@end smallexample


@subheading The @code{-data-evaluate-expression} Command
@findex -data-evaluate-expression

@subsubheading Synopsis

@example
 -data-evaluate-expression @var{expr}
@end example

Evaluate @var{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.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and
@samp{call}.  In @code{gdbtk} only, there's a corresponding
@samp{gdb_eval} command.

@subsubheading Example

In the following example, the numbers that precede the commands are the
@dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi}
Command Syntax}.  Notice how @sc{gdb/mi} returns the same tokens in its
output.

@smallexample
211-data-evaluate-expression A
211^done,value="1"
(@value{GDBP})
311-data-evaluate-expression &A
311^done,value="0xefffeb7c"
(@value{GDBP})
411-data-evaluate-expression A+3
411^done,value="4"
(@value{GDBP})
511-data-evaluate-expression "A + 3"
511^done,value="4"
(@value{GDBP})
@end smallexample


@subheading The @code{-data-list-changed-registers} Command
@findex -data-list-changed-registers

@subsubheading Synopsis

@example
 -data-list-changed-registers
@end example

Display a list of the registers that have changed.

@subsubheading @value{GDBN} Command

@value{GDBN} doesn't have a direct analog for this command; @code{gdbtk}
has the corresponding command @samp{gdb_changed_register_list}.

@subsubheading Example

On a PPC MBX board:

@smallexample
(@value{GDBP})
-exec-continue
^running

(@value{GDBP})
*stopped,reason="breakpoint-hit",bkptno="1",frame=@{func="main",
args=[],file="try.c",line="5"@}
(@value{GDBP})
-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"]
(@value{GDBP})
@end smallexample


@subheading The @code{-data-list-register-names} Command
@findex -data-list-register-names

@subsubheading Synopsis

@example
 -data-list-register-names [ ( @var{regno} )+ ]
@end example

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.

@subsubheading @value{GDBN} Command

@value{GDBN} does not have a command which corresponds to
@samp{-data-list-register-names}.  In @code{gdbtk} there is a
corresponding command @samp{gdb_regnames}.

@subsubheading Example

For the PPC MBX board:
@smallexample
(@value{GDBP})
-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"]
(@value{GDBP})
-data-list-register-names 1 2 3
^done,register-names=["r1","r2","r3"]
(@value{GDBP})
@end smallexample

@subheading The @code{-data-list-register-values} Command
@findex -data-list-register-values

@subsubheading Synopsis

@example
 -data-list-register-values @var{fmt} [ ( @var{regno} )*]
@end example

Display the registers' contents.  @var{fmt} is the format according to
which the registers' contents are to be returned, 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.

Allowed formats for @var{fmt} are:

@table @code
@item x
Hexadecimal
@item o
Octal
@item t
Binary
@item d
Decimal
@item r
Raw
@item N
Natural
@end table

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info
all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}.

@subsubheading Example

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

@smallexample
(@value{GDBP})
-data-list-register-values r 64 65
^done,register-values=[@{number="64",value="0xfe00a300"@},
@{number="65",value="0x00029002"@}]
(@value{GDBP})
-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"@}]
(@value{GDBP})
@end smallexample


@subheading The @code{-data-read-memory} Command
@findex -data-read-memory

@subsubheading Synopsis

@example
 -data-read-memory [ -o @var{byte-offset} ]
   @var{address} @var{word-format} @var{word-size}
   @var{nr-rows} @var{nr-cols} [ @var{aschar} ]
@end example

@noindent
where:

@table @samp
@item @var{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.

@item @var{word-format}
The format to be used to print the memory words.  The notation is the
same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats,
,Output formats}).

@item @var{word-size}
The size of each memory word in bytes.

@item @var{nr-rows}
The number of rows in the output table.

@item @var{nr-cols}
The number of columns in the output table.

@item @var{aschar}
If present, indicates that each row should include an @sc{ascii} dump.  The
value of @var{aschar} is used as a padding character when a byte is not a
member of the printable @sc{ascii} character set (printable @sc{ascii}
characters are those whose code is between 32 and 126, inclusively).

@item @var{byte-offset}
An offset to add to the @var{address} before fetching memory.
@end table

This command displays memory contents as a table of @var{nr-rows} by
@var{nr-cols} words, each word being @var{word-size} bytes.  In total,
@code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read
(returned as @samp{total-bytes}).  Should less than the requested number
of bytes be returned by the target, the missing words are identified
using @samp{N/A}.  The number of bytes read from the target is returned
in @samp{nr-bytes} and the starting address used to read memory in
@samp{addr}.

The address of the next/previous row or page is available in
@samp{next-row} and @samp{prev-row}, @samp{next-page} and
@samp{prev-page}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{x}.  @code{gdbtk} has
@samp{gdb_get_mem} memory read command.

@subsubheading Example

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

@smallexample
(@value{GDBP})
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"]@}]
(@value{GDBP})
@end smallexample

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

@smallexample
(@value{GDBP})
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"]@}]
(@value{GDBP})
@end smallexample

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

@smallexample
(@value{GDBP})
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=",-./"@}]
(@value{GDBP})
@end smallexample

@subheading The @code{-display-delete} Command
@findex -display-delete

@subsubheading Synopsis

@example
 -display-delete @var{number}
@end example

Delete the display @var{number}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{delete display}.

@subsubheading Example
N.A.


@subheading The @code{-display-disable} Command
@findex -display-disable

@subsubheading Synopsis

@example
 -display-disable @var{number}
@end example

Disable display @var{number}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{disable display}.

@subsubheading Example
N.A.


@subheading The @code{-display-enable} Command
@findex -display-enable

@subsubheading Synopsis

@example
 -display-enable @var{number}
@end example

Enable display @var{number}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{enable display}.

@subsubheading Example
N.A.


@subheading The @code{-display-insert} Command
@findex -display-insert

@subsubheading Synopsis

@example
 -display-insert @var{expression}
@end example

Display @var{expression} every time the program stops.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{display}.

@subsubheading Example
N.A.


@subheading The @code{-display-list} Command
@findex -display-list

@subsubheading Synopsis

@example
 -display-list
@end example

List the displays.  Do not show the current values.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info display}.

@subsubheading Example
N.A.


@subheading The @code{-environment-cd} Command
@findex -environment-cd

@subsubheading Synopsis

@example
 -environment-cd @var{pathdir}
@end example

Set @value{GDBN}'s working directory.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{cd}.

@subsubheading Example

@smallexample
(@value{GDBP})
-environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-environment-directory} Command
@findex -environment-directory

@subsubheading Synopsis

@example
 -environment-directory @var{pathdir}
@end example

Add directory @var{pathdir} to beginning of search path for source files.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{dir}.

@subsubheading Example

@smallexample
(@value{GDBP})
-environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-environment-path} Command
@findex -environment-path

@subsubheading Synopsis

@example
 -environment-path ( @var{pathdir} )+
@end example

Add directories @var{pathdir} to beginning of search path for object files.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{path}.

@subsubheading Example

@smallexample
(@value{GDBP})
-environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-environment-pwd} Command
@findex -environment-pwd

@subsubheading Synopsis

@example
 -environment-pwd
@end example

Show the current working directory.

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{pwd}.

@subsubheading Example

@smallexample
(@value{GDBP})
-environment-pwd
~Working directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb.
^done
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Program Control
@section @sc{gdb/mi} Program control

@subsubheading Program termination

As a result of execution, the inferior program can run to completion, if
it doesn't encounter any breakpoints.  In this case the output will
include an exit code, if the program has exited exceptionally.

@subsubheading Examples

@noindent
Program exited normally:

@smallexample
(@value{GDBP})
-exec-run
^running
(@value{GDBP})
x = 55
*stopped,reason="exited-normally"
(@value{GDBP})
@end smallexample

@noindent
Program exited exceptionally:

@smallexample
(@value{GDBP})
-exec-run
^running
(@value{GDBP})
x = 55
*stopped,reason="exited",exit-code="01"
(@value{GDBP})
@end smallexample

Another way the program can terminate is if it receives a signal such as
@code{SIGINT}.  In this case, @sc{gdb/mi} displays this:

@smallexample
(@value{GDBP})
*stopped,reason="exited-signalled",signal-name="SIGINT",
signal-meaning="Interrupt"
@end smallexample


@subheading The @code{-exec-abort} Command
@findex -exec-abort

@subsubheading Synopsis

@example
 -exec-abort
@end example

Kill the inferior running program.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{kill}.

@subsubheading Example
N.A.


@subheading The @code{-exec-arguments} Command
@findex -exec-arguments

@subsubheading Synopsis

@example
 -exec-arguments @var{args}
@end example

Set the inferior program arguments, to be used in the next
@samp{-exec-run}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{set args}.

@subsubheading Example

@c FIXME!
Don't have one around.


@subheading The @code{-exec-continue} Command
@findex -exec-continue

@subsubheading Synopsis

@example
 -exec-continue
@end example

Asynchronous command.  Resumes the execution of the inferior program
until a breakpoint is encountered, or until the inferior exits.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} corresponding is @samp{continue}.

@subsubheading Example

@smallexample
-exec-continue
^running
(@value{GDBP})
@@Hello world
*stopped,reason="breakpoint-hit",bkptno="2",frame=@{func="foo",args=[],
file="hello.c",line="13"@}
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-finish} Command
@findex -exec-finish

@subsubheading Synopsis

@example
 -exec-finish
@end example

Asynchronous command.  Resumes the execution of the inferior program
until the current function is exited.  Displays the results returned by
the function.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{finish}.

@subsubheading Example

Function returning @code{void}.

@smallexample
-exec-finish
^running
(@value{GDBP})
@@hello from foo
*stopped,reason="function-finished",frame=@{func="main",args=[],
file="hello.c",line="7"@}
(@value{GDBP})
@end smallexample

Function returning other than @code{void}.  The name of the internal
@value{GDBN} variable storing the result is printed, together with the
value itself.

@smallexample
-exec-finish
^running
(@value{GDBP})
*stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo",
args=[@{name="a",value="1"],@{name="b",value="9"@}@},
file="recursive2.c",line="14"@},
gdb-result-var="$1",return-value="0"
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-interrupt} Command
@findex -exec-interrupt

@subsubheading Synopsis

@example
 -exec-interrupt
@end example

Asynchronous command.  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 @samp{^done} output.  If the user is trying to
interrupt a non-running program, an error message will be printed.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{interrupt}.

@subsubheading Example

@smallexample
(@value{GDBP})
111-exec-continue
111^running

(@value{GDBP})
222-exec-interrupt
222^done
(@value{GDBP})
111*stopped,signal-name="SIGINT",signal-meaning="Interrupt",
frame=@{addr="0x00010140",func="foo",args=[],file="try.c",line="13"@}
(@value{GDBP})

(@value{GDBP})
-exec-interrupt
^error,msg="mi_cmd_exec_interrupt: Inferior not executing."
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-next} Command
@findex -exec-next

@subsubheading Synopsis

@example
 -exec-next
@end example

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

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{next}.

@subsubheading Example

@smallexample
-exec-next
^running
(@value{GDBP})
*stopped,reason="end-stepping-range",line="8",file="hello.c"
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-next-instruction} Command
@findex -exec-next-instruction

@subsubheading Synopsis

@example
 -exec-next-instruction
@end example

Asynchronous command.  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.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{nexti}.

@subsubheading Example

@smallexample
(@value{GDBP})
-exec-next-instruction
^running

(@value{GDBP})
*stopped,reason="end-stepping-range",
addr="0x000100d4",line="5",file="hello.c"
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-return} Command
@findex -exec-return

@subsubheading Synopsis

@example
 -exec-return
@end example

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

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{return}.

@subsubheading Example

@smallexample
(@value{GDBP})
200-break-insert callee4
200^done,bkpt=@{number="1",addr="0x00010734",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}
(@value{GDBP})
000-exec-run
000^running
(@value{GDBP})
000*stopped,reason="breakpoint-hit",bkptno="1",
frame=@{func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}
(@value{GDBP})
205-break-delete
205^done
(@value{GDBP})
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",line="18"@}
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-run} Command
@findex -exec-run

@subsubheading Synopsis

@example
 -exec-run
@end example

Asynchronous command.  Starts execution of the inferior from the
beginning.  The inferior executes until either a breakpoint is
encountered or the program exits.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{run}.

@subsubheading Example

@smallexample
(@value{GDBP})
-break-insert main
^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@}
(@value{GDBP})
-exec-run
^running
(@value{GDBP})
*stopped,reason="breakpoint-hit",bkptno="1",
frame=@{func="main",args=[],file="recursive2.c",line="4"@}
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-show-arguments} Command
@findex -exec-show-arguments

@subsubheading Synopsis

@example
 -exec-show-arguments
@end example

Print the arguments of the program.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{show args}.

@subsubheading Example
N.A.

@c @subheading -exec-signal

@subheading The @code{-exec-step} Command
@findex -exec-step

@subsubheading Synopsis

@example
 -exec-step
@end example

Asynchronous command.  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.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{step}.

@subsubheading Example

Stepping into a function:

@smallexample
-exec-step
^running
(@value{GDBP})
*stopped,reason="end-stepping-range",
frame=@{func="foo",args=[@{name="a",value="10"@},
@{name="b",value="0"@}],file="recursive2.c",line="11"@}
(@value{GDBP})
@end smallexample

Regular stepping:

@smallexample
-exec-step
^running
(@value{GDBP})
*stopped,reason="end-stepping-range",line="14",file="recursive2.c"
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-step-instruction} Command
@findex -exec-step-instruction

@subsubheading Synopsis

@example
 -exec-step-instruction
@end example

Asynchronous command.  Resumes the inferior which executes one machine
instruction.  The output, once @value{GDBN} 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.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{stepi}.

@subsubheading Example

@smallexample
(@value{GDBP})
-exec-step-instruction
^running

(@value{GDBP})
*stopped,reason="end-stepping-range",
frame=@{func="foo",args=[],file="try.c",line="10"@}
(@value{GDBP})
-exec-step-instruction
^running

(@value{GDBP})
*stopped,reason="end-stepping-range",
frame=@{addr="0x000100f4",func="foo",args=[],file="try.c",line="10"@}
(@value{GDBP})
@end smallexample


@subheading The @code{-exec-until} Command
@findex -exec-until

@subsubheading Synopsis

@example
 -exec-until [ @var{location} ]
@end example

Asynchronous command.  Executes the inferior until the @var{location}
specified in the argument is reached.  If there is no argument, the inferior
executes until a source line greater than the current one is reached.
The reason for stopping in this case will be @samp{location-reached}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{until}.

@subsubheading Example

@smallexample
(@value{GDBP})
-exec-until recursive2.c:6
^running
(@value{GDBP})
x = 55
*stopped,reason="location-reached",frame=@{func="main",args=[],
file="recursive2.c",line="6"@}
(@value{GDBP})
@end smallexample

@ignore
@subheading -file-clear
Is this going away????
@end ignore


@subheading The @code{-file-exec-and-symbols} Command
@findex -file-exec-and-symbols

@subsubheading Synopsis

@example
 -file-exec-and-symbols @var{file}
@end example

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, @value{GDBN} will produce
error messages.  Otherwise, no output is produced, except a completion
notification.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{file}.

@subsubheading Example

@smallexample
(@value{GDBP})
-file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-file-exec-file} Command
@findex -file-exec-file

@subsubheading Synopsis

@example
 -file-exec-file @var{file}
@end example

Specify the executable file to be debugged.  Unlike
@samp{-file-exec-and-symbols}, the symbol table is @emph{not} read
from this file.  If used without argument, @value{GDBN} clears the information
about the executable file.  No output is produced, except a completion
notification.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{exec-file}.

@subsubheading Example

@smallexample
(@value{GDBP})
-file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-file-list-exec-sections} Command
@findex -file-list-exec-sections

@subsubheading Synopsis

@example
 -file-list-exec-sections
@end example

List the sections of the current executable file.

@subsubheading @value{GDBN} Command

The @value{GDBN} command @samp{info file} shows, among the rest, the same
information as this command.  @code{gdbtk} has a corresponding command
@samp{gdb_load_info}.

@subsubheading Example
N.A.


@subheading The @code{-file-list-exec-source-files} Command
@findex -file-list-exec-source-files

@subsubheading Synopsis

@example
 -file-list-exec-source-files
@end example

List the source files for the current executable.

@subsubheading @value{GDBN} Command

There's no @value{GDBN} command which directly corresponds to this one.
@code{gdbtk} has an analogous command @samp{gdb_listfiles}.

@subsubheading Example
N.A.


@subheading The @code{-file-list-shared-libraries} Command
@findex -file-list-shared-libraries

@subsubheading Synopsis

@example
 -file-list-shared-libraries
@end example

List the shared libraries in the program.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info shared}.

@subsubheading Example
N.A.


@subheading The @code{-file-list-symbol-files} Command
@findex -file-list-symbol-files

@subsubheading Synopsis

@example
 -file-list-symbol-files
@end example

List symbol files.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info file} (part of it).

@subsubheading Example
N.A.


@subheading The @code{-file-symbol-file} Command
@findex -file-symbol-file

@subsubheading Synopsis

@example
 -file-symbol-file @var{file}
@end example

Read symbol table info from the specified @var{file} argument.  When
used without arguments, clears @value{GDBN}'s symbol table info.  No output is
produced, except for a completion notification.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{symbol-file}.

@subsubheading Example

@smallexample
(@value{GDBP})
-file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx
^done
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Miscellaneous Commands
@section Miscellaneous @value{GDBN} commands in @sc{gdb/mi}

@c @subheading -gdb-complete

@subheading The @code{-gdb-exit} Command
@findex -gdb-exit

@subsubheading Synopsis

@example
 -gdb-exit
@end example

Exit @value{GDBN} immediately.

@subsubheading @value{GDBN} Command

Approximately corresponds to @samp{quit}.

@subsubheading Example

@smallexample
(@value{GDBP})
-gdb-exit
@end smallexample

@subheading The @code{-gdb-set} Command
@findex -gdb-set

@subsubheading Synopsis

@example
 -gdb-set
@end example

Set an internal @value{GDBN} variable.
@c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ?????

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{set}.

@subsubheading Example

@smallexample
(@value{GDBP})
-gdb-set $foo=3
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-gdb-show} Command
@findex -gdb-show

@subsubheading Synopsis

@example
 -gdb-show
@end example

Show the current value of a @value{GDBN} variable.

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{show}.

@subsubheading Example

@smallexample
(@value{GDBP})
-gdb-show annotate
^done,value="0"
(@value{GDBP})
@end smallexample

@c @subheading -gdb-source


@subheading The @code{-gdb-version} Command
@findex -gdb-version

@subsubheading Synopsis

@example
 -gdb-version
@end example

Show version information for @value{GDBN}.  Used mostly in testing.

@subsubheading @value{GDBN} Command

There's no equivalent @value{GDBN} command.  @value{GDBN} by default shows this
information when you start an interactive session.

@subsubheading Example

@c This example modifies the actual output from GDB to avoid overfull
@c box in TeX.
@smallexample
(@value{GDBP})
-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
(@value{GDBP})
@end smallexample

@ignore
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Kod Commands
@section @sc{gdb/mi} Kod Commands

The Kod commands are not implemented.

@c @subheading -kod-info

@c @subheading -kod-list

@c @subheading -kod-list-object-types

@c @subheading -kod-show

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Memory Overlay Commands
@section @sc{gdb/mi} Memory Overlay Commands

The memory overlay commands are not implemented.

@c @subheading -overlay-auto

@c @subheading -overlay-list-mapping-state

@c @subheading -overlay-list-overlays

@c @subheading -overlay-map

@c @subheading -overlay-off

@c @subheading -overlay-on

@c @subheading -overlay-unmap

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Signal Handling Commands
@section @sc{gdb/mi} Signal Handling Commands

Signal handling commands are not implemented.

@c @subheading -signal-handle

@c @subheading -signal-list-handle-actions

@c @subheading -signal-list-signal-types
@end ignore


@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Stack Manipulation
@section @sc{gdb/mi} Stack Manipulation Commands


@subheading The @code{-stack-info-frame} Command
@findex -stack-info-frame

@subsubheading Synopsis

@example
 -stack-info-frame
@end example

Get info on the current frame.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame}
(without arguments).

@subsubheading Example
N.A.

@subheading The @code{-stack-info-depth} Command
@findex -stack-info-depth

@subsubheading Synopsis

@example
 -stack-info-depth [ @var{max-depth} ]
@end example

Return the depth of the stack.  If the integer argument @var{max-depth}
is specified, do not count beyond @var{max-depth} frames.

@subsubheading @value{GDBN} Command

There's no equivalent @value{GDBN} command.

@subsubheading Example

For a stack with frame levels 0 through 11:

@smallexample
(@value{GDBP})
-stack-info-depth
^done,depth="12"
(@value{GDBP})
-stack-info-depth 4
^done,depth="4"
(@value{GDBP})
-stack-info-depth 12
^done,depth="12"
(@value{GDBP})
-stack-info-depth 11
^done,depth="11"
(@value{GDBP})
-stack-info-depth 13
^done,depth="12"
(@value{GDBP})
@end smallexample

@subheading The @code{-stack-list-arguments} Command
@findex -stack-list-arguments

@subsubheading Synopsis

@example
 -stack-list-arguments @var{show-values}
    [ @var{low-frame} @var{high-frame} ]
@end example

Display a list of the arguments for the frames between @var{low-frame}
and @var{high-frame} (inclusive).  If @var{low-frame} and
@var{high-frame} are not provided, list the arguments for the whole call
stack.

The @var{show-values} argument must have a value of 0 or 1.  A value of
0 means that only the names of the arguments are listed, a value of 1
means that both names and values of the arguments are printed.

@subsubheading @value{GDBN} Command

@value{GDBN} does not have an equivalent command.  @code{gdbtk} has a
@samp{gdb_get_args} command which partially overlaps with the
functionality of @samp{-stack-list-arguments}.

@subsubheading Example

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

@c @subheading -stack-list-exception-handlers


@subheading The @code{-stack-list-frames} Command
@findex -stack-list-frames

@subsubheading Synopsis

@example
 -stack-list-frames [ @var{low-frame} @var{high-frame} ]
@end example

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

@table @samp
@item @var{level}
The frame number, 0 being the topmost frame, i.e. the innermost function.
@item @var{addr}
The @code{$pc} value for that frame.
@item @var{func}
Function name.
@item @var{file}
File name of the source file where the function lives.
@item @var{line}
Line number corresponding to the @code{$pc}.
@end table

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.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}.

@subsubheading Example

Full stack backtrace:

@smallexample
(@value{GDBP})
-stack-list-frames
^done,stack=
[frame=@{level="0 ",addr="0x0001076c",func="foo",
  file="recursive2.c",line="11"@},
frame=@{level="1 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="2 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="3 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="4 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="5 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="6 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="7 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="8 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="9 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="10",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="11",addr="0x00010738",func="main",
  file="recursive2.c",line="4"@}]
(@value{GDBP})
@end smallexample

Show frames between @var{low_frame} and @var{high_frame}:

@smallexample
(@value{GDBP})
-stack-list-frames 3 5
^done,stack=
[frame=@{level="3 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="4 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@},
frame=@{level="5 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@}]
(@value{GDBP})
@end smallexample

Show a single frame:

@smallexample
(@value{GDBP})
-stack-list-frames 3 3
^done,stack=
[frame=@{level="3 ",addr="0x000107a4",func="foo",
  file="recursive2.c",line="14"@}]
(@value{GDBP})
@end smallexample


@subheading The @code{-stack-list-locals} Command
@findex -stack-list-locals

@subsubheading Synopsis

@example
 -stack-list-locals @var{print-values}
@end example

Display the local variable names for the current frame.  With an
argument of 0 prints only the names of the variables, with argument of 1
prints also their values.

@subsubheading @value{GDBN} Command

@samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}.

@subsubheading Example

@smallexample
(@value{GDBP})
-stack-list-locals 0
^done,locals=[name="A",name="B",name="C"]
(@value{GDBP})
-stack-list-locals 1
^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@},
  @{name="C",value="3"@}]
(@value{GDBP})
@end smallexample


@subheading The @code{-stack-select-frame} Command
@findex -stack-select-frame

@subsubheading Synopsis

@example
 -stack-select-frame @var{framenum}
@end example

Change the current frame.  Select a different frame @var{framenum} on
the stack.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} commands are @samp{frame}, @samp{up},
@samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}.

@subsubheading Example

@smallexample
(@value{GDBP})
-stack-select-frame 2
^done
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Symbol Query
@section @sc{gdb/mi} Symbol Query Commands


@subheading The @code{-symbol-info-address} Command
@findex -symbol-info-address

@subsubheading Synopsis

@example
 -symbol-info-address @var{symbol}
@end example

Describe where @var{symbol} is stored.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info address}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-info-file} Command
@findex -symbol-info-file

@subsubheading Synopsis

@example
 -symbol-info-file
@end example

Show the file for the symbol.

@subsubheading @value{GDBN} Command

There's no equivalent @value{GDBN} command.  @code{gdbtk} has
@samp{gdb_find_file}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-info-function} Command
@findex -symbol-info-function

@subsubheading Synopsis

@example
 -symbol-info-function
@end example

Show which function the symbol lives in.

@subsubheading @value{GDBN} Command

@samp{gdb_get_function} in @code{gdbtk}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-info-line} Command
@findex -symbol-info-line

@subsubheading Synopsis

@example
 -symbol-info-line
@end example

Show the core addresses of the code for a source line.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} comamnd is @samp{info line}.
@code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands.

@subsubheading Example
N.A.


@subheading The @code{-symbol-info-symbol} Command
@findex -symbol-info-symbol

@subsubheading Synopsis

@example
 -symbol-info-symbol @var{addr}
@end example

Describe what symbol is at location @var{addr}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{info symbol}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-list-functions} Command
@findex -symbol-list-functions

@subsubheading Synopsis

@example
 -symbol-list-functions
@end example

List the functions in the executable.

@subsubheading @value{GDBN} Command

@samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and
@samp{gdb_search} in @code{gdbtk}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-list-types} Command
@findex -symbol-list-types

@subsubheading Synopsis

@example
 -symbol-list-types
@end example

List all the type names.

@subsubheading @value{GDBN} Command

The corresponding commands are @samp{info types} in @value{GDBN},
@samp{gdb_search} in @code{gdbtk}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-list-variables} Command
@findex -symbol-list-variables

@subsubheading Synopsis

@example
 -symbol-list-variables
@end example

List all the global and static variable names.

@subsubheading @value{GDBN} Command

@samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-locate} Command
@findex -symbol-locate

@subsubheading Synopsis

@example
 -symbol-locate
@end example

@subsubheading @value{GDBN} Command

@samp{gdb_loc} in @code{gdbtk}.

@subsubheading Example
N.A.


@subheading The @code{-symbol-type} Command
@findex -symbol-type

@subsubheading Synopsis

@example
 -symbol-type @var{variable}
@end example

Show type of @var{variable}.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has
@samp{gdb_obj_variable}.

@subsubheading Example
N.A.


@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Target Manipulation
@section @sc{gdb/mi} Target Manipulation Commands


@subheading The @code{-target-attach} Command
@findex -target-attach

@subsubheading Synopsis

@example
 -target-attach @var{pid} | @var{file}
@end example

Attach to a process @var{pid} or a file @var{file} outside of @value{GDBN}.

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{attach}.

@subsubheading Example
N.A.


@subheading The @code{-target-compare-sections} Command
@findex -target-compare-sections

@subsubheading Synopsis

@example
 -target-compare-sections [ @var{section} ]
@end example

Compare data of section @var{section} on target to the exec file.
Without the argument, all sections are compared.

@subsubheading @value{GDBN} Command

The @value{GDBN} equivalent is @samp{compare-sections}.

@subsubheading Example
N.A.


@subheading The @code{-target-detach} Command
@findex -target-detach

@subsubheading Synopsis

@example
 -target-detach
@end example

Disconnect from the remote target.  There's no output.

@subsubheading @value{GDBN} command

The corresponding @value{GDBN} command is @samp{detach}.

@subsubheading Example

@smallexample
(@value{GDBP})
-target-detach
^done
(@value{GDBP})
@end smallexample


@subheading The @code{-target-download} Command
@findex -target-download

@subsubheading Synopsis

@example
 -target-download
@end example

Loads the executable onto the remote target.
It prints out an update message every half second, which includes the fields:

@table @samp
@item section
The name of the section.
@item section-sent
The size of what has been sent so far for that section.
@item section-size
The size of the section.
@item total-sent
The total size of what was sent so far (the current and the previous sections).
@item total-size
The size of the overall executable to download.
@end table

@noindent
Each message is sent as status record (@pxref{GDB/MI Output Syntax, ,
@sc{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:

@table @samp
@item section
The name of the section.
@item section-size
The size of the section.
@item total-size
The size of the overall executable to download.
@end table

@noindent
At the end, a summary is printed.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{load}.

@subsubheading 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.

@smallexample
(@value{GDBP})
-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"
(@value{GDBP})
@end smallexample


@subheading The @code{-target-exec-status} Command
@findex -target-exec-status

@subsubheading Synopsis

@example
 -target-exec-status
@end example

Provide information on the state of the target (whether it is running or
not, for instance).

@subsubheading @value{GDBN} Command

There's no equivalent @value{GDBN} command.

@subsubheading Example
N.A.


@subheading The @code{-target-list-available-targets} Command
@findex -target-list-available-targets

@subsubheading Synopsis

@example
 -target-list-available-targets
@end example

List the possible targets to connect to.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{help target}.

@subsubheading Example
N.A.


@subheading The @code{-target-list-current-targets} Command
@findex -target-list-current-targets

@subsubheading Synopsis

@example
 -target-list-current-targets
@end example

Describe the current target.

@subsubheading @value{GDBN} Command

The corresponding information is printed by @samp{info file} (among
other things).

@subsubheading Example
N.A.


@subheading The @code{-target-list-parameters} Command
@findex -target-list-parameters

@subsubheading Synopsis

@example
 -target-list-parameters
@end example

@c ????

@subsubheading @value{GDBN} Command

No equivalent.

@subsubheading Example
N.A.


@subheading The @code{-target-select} Command
@findex -target-select

@subsubheading Synopsis

@example
 -target-select @var{type} @var{parameters @dots{}}
@end example

Connect @value{GDBN} to the remote target.  This command takes two args:

@table @samp
@item @var{type}
The type of target, for instance @samp{async}, @samp{remote}, etc.
@item @var{parameters}
Device names, host names and the like.  @xref{Target Commands, ,
Commands for managing targets}, for more details.
@end table

The output is a connection notification, followed by the address at
which the target program is, in the following form:

@smallexample
^connected,addr="@var{address}",func="@var{function name}",
  args=[@var{arg list}]
@end smallexample

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{target}.

@subsubheading Example

@smallexample
(@value{GDBP})
-target-select async /dev/ttya
^connected,addr="0xfe00a300",func="??",args=[]
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Thread Commands
@section @sc{gdb/mi} Thread Commands


@subheading The @code{-thread-info} Command
@findex -thread-info

@subsubheading Synopsis

@example
 -thread-info
@end example

@subsubheading @value{GDBN} command

No equivalent.

@subsubheading Example
N.A.


@subheading The @code{-thread-list-all-threads} Command
@findex -thread-list-all-threads

@subsubheading Synopsis

@example
 -thread-list-all-threads
@end example

@subsubheading @value{GDBN} Command

The equivalent @value{GDBN} command is @samp{info threads}.

@subsubheading Example
N.A.


@subheading The @code{-thread-list-ids} Command
@findex -thread-list-ids

@subsubheading Synopsis

@example
 -thread-list-ids
@end example

Produces a list of the currently known @value{GDBN} thread ids.  At the
end of the list it also prints the total number of such threads.

@subsubheading @value{GDBN} Command

Part of @samp{info threads} supplies the same information.

@subsubheading Example

No threads present, besides the main process:

@smallexample
(@value{GDBP})
-thread-list-ids
^done,thread-ids=@{@},number-of-threads="0"
(@value{GDBP})
@end smallexample


Several threads:

@smallexample
(@value{GDBP})
-thread-list-ids
^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@},
number-of-threads="3"
(@value{GDBP})
@end smallexample


@subheading The @code{-thread-select} Command
@findex -thread-select

@subsubheading Synopsis

@example
 -thread-select @var{threadnum}
@end example

Make @var{threadnum} the current thread.  It prints the number of the new
current thread, and the topmost frame for that thread.

@subsubheading @value{GDBN} Command

The corresponding @value{GDBN} command is @samp{thread}.

@subsubheading Example

@smallexample
(@value{GDBP})
-exec-next
^running
(@value{GDBP})
*stopped,reason="end-stepping-range",thread-id="2",line="187",
file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c"
(@value{GDBP})
-thread-list-ids
^done,
thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@},
number-of-threads="3"
(@value{GDBP})
-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"@}
(@value{GDBP})
@end smallexample

@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Tracepoint Commands
@section @sc{gdb/mi} Tracepoint Commands

The tracepoint commands are not yet implemented.

@c @subheading -trace-actions

@c @subheading -trace-delete

@c @subheading -trace-disable

@c @subheading -trace-dump

@c @subheading -trace-enable

@c @subheading -trace-exists

@c @subheading -trace-find

@c @subheading -trace-frame-number

@c @subheading -trace-info

@c @subheading -trace-insert

@c @subheading -trace-list

@c @subheading -trace-pass-count

@c @subheading -trace-save

@c @subheading -trace-start

@c @subheading -trace-stop


@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Variable Objects
@section @sc{gdb/mi} Variable Objects


@subheading Motivation for Variable Objects in @sc{gdb/mi}

For the implementation of a variable debugger window (locals, watched
expressions, etc.), we are proposing the adaptation of the existing code
used by @code{Insight}.

The two main reasons for that are:

@enumerate 1
@item
It has been proven in practice (it is already on its second generation).

@item
It will shorten development time (needless to say how important it is
now).
@end enumerate

The original interface was designed to be used by Tcl code, so it was
slightly changed so it could be used through @sc{gdb/mi}.  This section
describes the @sc{gdb/mi} operations that will be available and gives some
hints about their use.

@emph{Note}: In addition to the set of operations described here, we
expect the @sc{gui} implementation of a variable window to require, at
least, the following operations:

@itemize @bullet
@item @code{-gdb-show} @code{output-radix}
@item @code{-stack-list-arguments}
@item @code{-stack-list-locals}
@item @code{-stack-select-frame}
@end itemize

@subheading Introduction to Variable Objects in @sc{gdb/mi}

@cindex variable objects in @sc{gdb/mi}
The basic idea behind variable objects is the creation of a named object
to represent a variable, an expression, a memory location or even a CPU
register.  For each object created, a set of operations is available for
examining or changing its properties.

Furthermore, complex data types, such as C structures, are represented
in a tree format.  For instance, the @code{struct} type variable is the
root and the children will represent the struct members.  If a child
is itself of a complex type, it will also have children of its own.
Appropriate language differences are handled for C, C@t{++} and Java.

When returning the actual values of the objects, this facility allows
for the individual selection of the display format used in the result
creation.  It can be chosen among: binary, decimal, hexadecimal, octal
and natural.  Natural refers to a default format automatically
chosen based on the variable type (like decimal for an @code{int}, hex
for pointers, etc.).

The following is the complete set of @sc{gdb/mi} operations defined to
access this functionality:

@multitable @columnfractions .4 .6
@item @strong{Operation}
@tab @strong{Description}

@item @code{-var-create}
@tab create a variable object
@item @code{-var-delete}
@tab delete the variable object and its children
@item @code{-var-set-format}
@tab set the display format of this variable
@item @code{-var-show-format}
@tab show the display format of this variable
@item @code{-var-info-num-children}
@tab tells how many children this object has
@item @code{-var-list-children}
@tab return a list of the object's children
@item @code{-var-info-type}
@tab show the type of this variable object
@item @code{-var-info-expression}
@tab print what this variable object represents
@item @code{-var-show-attributes}
@tab is this variable editable? does it exist here?
@item @code{-var-evaluate-expression}
@tab get the value of this variable
@item @code{-var-assign}
@tab set the value of this variable
@item @code{-var-update}
@tab update the variable and its children
@end multitable

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

@subheading Description And Use of Operations on Variable Objects

@subheading The @code{-var-create} Command
@findex -var-create

@subsubheading Synopsis

@example
 -var-create @{@var{name} | "-"@}
    @{@var{frame-addr} | "*"@} @var{expression}
@end example

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

The frame under which the expression should be evaluated can be
specified by @var{frame-addr}.  A @samp{*} indicates that the current
frame should be used.

@var{expression} is any expression valid on the current language set (must not
begin with a @samp{*}), or one of the following:

@itemize @bullet
@item
@samp{*@var{addr}}, where @var{addr} is the address of a memory cell

@item
@samp{*@var{addr}-@var{addr}} --- a memory address range (TBD)

@item
@samp{$@var{regname}} --- a CPU register name
@end itemize

@subsubheading Result

This operation returns the name, number of children and the type of the
object created.  Type is returned as a string as the ones generated by
the @value{GDBN} CLI:

@example
 name="@var{name}",numchild="N",type="@var{type}"
@end example


@subheading The @code{-var-delete} Command
@findex -var-delete

@subsubheading Synopsis

@example
 -var-delete @var{name}
@end example

Deletes a previously created variable object and all of its children.

Returns an error if the object @var{name} is not found.


@subheading The @code{-var-set-format} Command
@findex -var-set-format

@subsubheading Synopsis

@example
 -var-set-format @var{name} @var{format-spec}
@end example

Sets the output format for the value of the object @var{name} to be
@var{format-spec}.

The syntax for the @var{format-spec} is as follows:

@example
 @var{format-spec} @expansion{}
 @{binary | decimal | hexadecimal | octal | natural@}
@end example


@subheading The @code{-var-show-format} Command
@findex -var-show-format

@subsubheading Synopsis

@example
 -var-show-format @var{name}
@end example

Returns the format used to display the value of the object @var{name}.

@example
 @var{format} @expansion{}
 @var{format-spec}
@end example


@subheading The @code{-var-info-num-children} Command
@findex -var-info-num-children

@subsubheading Synopsis

@example
 -var-info-num-children @var{name}
@end example

Returns the number of children of a variable object @var{name}:

@example
 numchild=@var{n}
@end example


@subheading The @code{-var-list-children} Command
@findex -var-list-children

@subsubheading Synopsis

@example
 -var-list-children @var{name}
@end example

Returns a list of the children of the specified variable object:

@example
 numchild=@var{n},children=@{@{name=@var{name},
 numchild=@var{n},type=@var{type}@},@r{(repeats N times)}@}
@end example


@subheading The @code{-var-info-type} Command
@findex -var-info-type

@subsubheading Synopsis

@example
 -var-info-type @var{name}
@end example

Returns the type of the specified variable @var{name}.  The type is
returned as a string in the same format as it is output by the
@value{GDBN} CLI:

@example
 type=@var{typename}
@end example


@subheading The @code{-var-info-expression} Command
@findex -var-info-expression

@subsubheading Synopsis

@example
 -var-info-expression @var{name}
@end example

Returns what is represented by the variable object @var{name}:

@example
 lang=@var{lang-spec},exp=@var{expression}
@end example

@noindent
where @var{lang-spec} is @code{@{"C" | "C++" | "Java"@}}.

@subheading The @code{-var-show-attributes} Command
@findex -var-show-attributes

@subsubheading Synopsis

@example
 -var-show-attributes @var{name}
@end example

List attributes of the specified variable object @var{name}:

@example
 status=@var{attr} [ ( ,@var{attr} )* ]
@end example

@noindent
where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}.

@subheading The @code{-var-evaluate-expression} Command
@findex -var-evaluate-expression

@subsubheading Synopsis

@example
 -var-evaluate-expression @var{name}
@end example

Evaluates the expression that is represented by the specified variable
object and returns its value as a string in the current format specified
for the object:

@example
 value=@var{value}
@end example

@subheading The @code{-var-assign} Command
@findex -var-assign

@subsubheading Synopsis

@example
 -var-assign @var{name} @var{expression}
@end example

Assigns the value of @var{expression} to the variable object specified
by @var{name}.  The object must be @samp{editable}.

@subheading The @code{-var-update} Command
@findex -var-update

@subsubheading Synopsis

@example
 -var-update @{@var{name} | "*"@}
@end example

Update the value of the variable object @var{name} by evaluating its
expression after fetching all the new values from memory or registers.
A @samp{*} causes all existing variable objects to be updated.