375 lines
20 KiB
HTML
375 lines
20 KiB
HTML
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>Basic Python - Debugging with GDB</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Debugging with GDB">
|
||
|
|
<meta name="generator" content="makeinfo 4.13">
|
||
|
|
<link title="Top" rel="start" href="index.html#Top">
|
||
|
|
<link rel="up" href="Python-API.html#Python-API" title="Python API">
|
||
|
|
<link rel="next" href="Exception-Handling.html#Exception-Handling" title="Exception Handling">
|
||
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
||
|
|
<!--
|
||
|
|
Copyright (C) 1988-2019 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
||
|
|
any later version published by the Free Software Foundation; with the
|
||
|
|
Invariant Sections being ``Free Software'' and ``Free Software Needs
|
||
|
|
Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,''
|
||
|
|
and with the Back-Cover Texts as in (a) below.
|
||
|
|
|
||
|
|
(a) The FSF's Back-Cover Text is: ``You are free to copy and modify
|
||
|
|
this GNU Manual. Buying copies from GNU Press supports the FSF in
|
||
|
|
developing GNU and promoting software freedom.''
|
||
|
|
-->
|
||
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
||
|
|
<style type="text/css"><!--
|
||
|
|
pre.display { font-family:inherit }
|
||
|
|
pre.format { font-family:inherit }
|
||
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallexample { font-size:smaller }
|
||
|
|
pre.smalllisp { font-size:smaller }
|
||
|
|
span.sc { font-variant:small-caps }
|
||
|
|
span.roman { font-family:serif; font-weight:normal; }
|
||
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="node">
|
||
|
|
<a name="Basic-Python"></a>
|
||
|
|
<p>
|
||
|
|
Next: <a rel="next" accesskey="n" href="Exception-Handling.html#Exception-Handling">Exception Handling</a>,
|
||
|
|
Up: <a rel="up" accesskey="u" href="Python-API.html#Python-API">Python API</a>
|
||
|
|
<hr>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<h5 class="subsubsection">23.2.2.1 Basic Python</h5>
|
||
|
|
|
||
|
|
<p><a name="index-python-stdout-1848"></a><a name="index-python-pagination-1849"></a>At startup, <span class="sc">gdb</span> overrides Python's <code>sys.stdout</code> and
|
||
|
|
<code>sys.stderr</code> to print using <span class="sc">gdb</span>'s output-paging streams.
|
||
|
|
A Python program which outputs to one of these streams may have its
|
||
|
|
output interrupted by the user (see <a href="Screen-Size.html#Screen-Size">Screen Size</a>). In this
|
||
|
|
situation, a Python <code>KeyboardInterrupt</code> exception is thrown.
|
||
|
|
|
||
|
|
<p>Some care must be taken when writing Python code to run in
|
||
|
|
<span class="sc">gdb</span>. Two things worth noting in particular:
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li><span class="sc">gdb</span> install handlers for <code>SIGCHLD</code> and <code>SIGINT</code>.
|
||
|
|
Python code must not override these, or even change the options using
|
||
|
|
<code>sigaction</code>. If your program changes the handling of these
|
||
|
|
signals, <span class="sc">gdb</span> will most likely stop working correctly. Note
|
||
|
|
that it is unfortunately common for GUI toolkits to install a
|
||
|
|
<code>SIGCHLD</code> handler.
|
||
|
|
|
||
|
|
<li><span class="sc">gdb</span> takes care to mark its internal file descriptors as
|
||
|
|
close-on-exec. However, this cannot be done in a thread-safe way on
|
||
|
|
all platforms. Your Python programs should be aware of this and
|
||
|
|
should both create new file descriptors with the close-on-exec flag
|
||
|
|
set and arrange to close unneeded file descriptors before starting a
|
||
|
|
child process.
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p><a name="index-python-functions-1850"></a><a name="index-python-module-1851"></a><a name="index-gdb-module-1852"></a><span class="sc">gdb</span> introduces a new Python module, named <code>gdb</code>. All
|
||
|
|
methods and classes added by <span class="sc">gdb</span> are placed in this module.
|
||
|
|
<span class="sc">gdb</span> automatically <code>import</code>s the <code>gdb</code> module for
|
||
|
|
use in all scripts evaluated by the <code>python</code> command.
|
||
|
|
|
||
|
|
<p>Some types of the <code>gdb</code> module come with a textual representation
|
||
|
|
(accessible through the <code>repr</code> or <code>str</code> functions). These are
|
||
|
|
offered for debugging purposes only, expect them to change over time.
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002ePYTHONDIR-1853"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Variable: <b>gdb.PYTHONDIR</b><var><a name="index-gdb_002ePYTHONDIR-1854"></a></var><br>
|
||
|
|
<blockquote><p>A string containing the python directory (see <a href="Python.html#Python">Python</a>).
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002eexecute-1855"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.execute</b> (<var>command </var><span class="roman">[</span><var>, from_tty </var><span class="roman">[</span><var>, to_string</var><span class="roman">]]</span>)<var><a name="index-gdb_002eexecute-1856"></a></var><br>
|
||
|
|
<blockquote><p>Evaluate <var>command</var>, a string, as a <span class="sc">gdb</span> CLI command.
|
||
|
|
If a GDB exception happens while <var>command</var> runs, it is
|
||
|
|
translated as described in <a href="Exception-Handling.html#Exception-Handling">Exception Handling</a>.
|
||
|
|
|
||
|
|
<p>The <var>from_tty</var> flag specifies whether <span class="sc">gdb</span> ought to consider this
|
||
|
|
command as having originated from the user invoking it interactively.
|
||
|
|
It must be a boolean value. If omitted, it defaults to <code>False</code>.
|
||
|
|
|
||
|
|
<p>By default, any output produced by <var>command</var> is sent to
|
||
|
|
<span class="sc">gdb</span>'s standard output (and to the log output if logging is
|
||
|
|
turned on). If the <var>to_string</var> parameter is
|
||
|
|
<code>True</code>, then output will be collected by <code>gdb.execute</code> and
|
||
|
|
returned as a string. The default is <code>False</code>, in which case the
|
||
|
|
return value is <code>None</code>. If <var>to_string</var> is <code>True</code>, the
|
||
|
|
<span class="sc">gdb</span> virtual terminal will be temporarily set to unlimited width
|
||
|
|
and height, and its pagination will be disabled; see <a href="Screen-Size.html#Screen-Size">Screen Size</a>.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002ebreakpoints-1857"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.breakpoints</b> ()<var><a name="index-gdb_002ebreakpoints-1858"></a></var><br>
|
||
|
|
<blockquote><p>Return a sequence holding all of <span class="sc">gdb</span>'s breakpoints.
|
||
|
|
See <a href="Breakpoints-In-Python.html#Breakpoints-In-Python">Breakpoints In Python</a>, for more information. In <span class="sc">gdb</span>
|
||
|
|
version 7.11 and earlier, this function returned <code>None</code> if there
|
||
|
|
were no breakpoints. This peculiarity was subsequently fixed, and now
|
||
|
|
<code>gdb.breakpoints</code> returns an empty sequence in this case.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.rbreak</b> (<var>regex </var><span class="roman">[</span><var>, minsyms </var><span class="roman">[</span><var>, throttle, </var><span class="roman">[</span><var>, symtabs </var><span class="roman">]]]</span>)<var><a name="index-gdb_002erbreak-1859"></a></var><br>
|
||
|
|
<blockquote><p>Return a Python list holding a collection of newly set
|
||
|
|
<code>gdb.Breakpoint</code> objects matching function names defined by the
|
||
|
|
<var>regex</var> pattern. If the <var>minsyms</var> keyword is <code>True</code>, all
|
||
|
|
system functions (those not explicitly defined in the inferior) will
|
||
|
|
also be included in the match. The <var>throttle</var> keyword takes an
|
||
|
|
integer that defines the maximum number of pattern matches for
|
||
|
|
functions matched by the <var>regex</var> pattern. If the number of
|
||
|
|
matches exceeds the integer value of <var>throttle</var>, a
|
||
|
|
<code>RuntimeError</code> will be raised and no breakpoints will be created.
|
||
|
|
If <var>throttle</var> is not defined then there is no imposed limit on the
|
||
|
|
maximum number of matches and breakpoints to be created. The
|
||
|
|
<var>symtabs</var> keyword takes a Python iterable that yields a collection
|
||
|
|
of <code>gdb.Symtab</code> objects and will restrict the search to those
|
||
|
|
functions only contained within the <code>gdb.Symtab</code> objects.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002eparameter-1860"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.parameter</b> (<var>parameter</var>)<var><a name="index-gdb_002eparameter-1861"></a></var><br>
|
||
|
|
<blockquote><p>Return the value of a <span class="sc">gdb</span> <var>parameter</var> given by its name,
|
||
|
|
a string; the parameter name string may contain spaces if the parameter has a
|
||
|
|
multi-part name. For example, ‘<samp><span class="samp">print object</span></samp>’ is a valid
|
||
|
|
parameter name.
|
||
|
|
|
||
|
|
<p>If the named parameter does not exist, this function throws a
|
||
|
|
<code>gdb.error</code> (see <a href="Exception-Handling.html#Exception-Handling">Exception Handling</a>). Otherwise, the
|
||
|
|
parameter's value is converted to a Python value of the appropriate
|
||
|
|
type, and returned.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002ehistory-1862"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.history</b> (<var>number</var>)<var><a name="index-gdb_002ehistory-1863"></a></var><br>
|
||
|
|
<blockquote><p>Return a value from <span class="sc">gdb</span>'s value history (see <a href="Value-History.html#Value-History">Value History</a>). The <var>number</var> argument indicates which history element to return.
|
||
|
|
If <var>number</var> is negative, then <span class="sc">gdb</span> will take its absolute value
|
||
|
|
and count backward from the last element (i.e., the most recent element) to
|
||
|
|
find the value to return. If <var>number</var> is zero, then <span class="sc">gdb</span> will
|
||
|
|
return the most recent element. If the element specified by <var>number</var>
|
||
|
|
doesn't exist in the value history, a <code>gdb.error</code> exception will be
|
||
|
|
raised.
|
||
|
|
|
||
|
|
<p>If no exception is raised, the return value is always an instance of
|
||
|
|
<code>gdb.Value</code> (see <a href="Values-From-Inferior.html#Values-From-Inferior">Values From Inferior</a>).
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002econvenience_005fvariable-1864"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.convenience_variable</b> (<var>name</var>)<var><a name="index-gdb_002econvenience_005fvariable-1865"></a></var><br>
|
||
|
|
<blockquote><p>Return the value of the convenience variable (see <a href="Convenience-Vars.html#Convenience-Vars">Convenience Vars</a>) named <var>name</var>. <var>name</var> must be a string. The name
|
||
|
|
should not include the ‘<samp><span class="samp">$</span></samp>’ that is used to mark a convenience
|
||
|
|
variable in an expression. If the convenience variable does not
|
||
|
|
exist, then <code>None</code> is returned.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002eset_005fconvenience_005fvariable-1866"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.set_convenience_variable</b> (<var>name, value</var>)<var><a name="index-gdb_002eset_005fconvenience_005fvariable-1867"></a></var><br>
|
||
|
|
<blockquote><p>Set the value of the convenience variable (see <a href="Convenience-Vars.html#Convenience-Vars">Convenience Vars</a>)
|
||
|
|
named <var>name</var>. <var>name</var> must be a string. The name should not
|
||
|
|
include the ‘<samp><span class="samp">$</span></samp>’ that is used to mark a convenience variable in an
|
||
|
|
expression. If <var>value</var> is <code>None</code>, then the convenience
|
||
|
|
variable is removed. Otherwise, if <var>value</var> is not a
|
||
|
|
<code>gdb.Value</code> (see <a href="Values-From-Inferior.html#Values-From-Inferior">Values From Inferior</a>), it is is converted
|
||
|
|
using the <code>gdb.Value</code> constructor.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002eparse_005fand_005feval-1868"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.parse_and_eval</b> (<var>expression</var>)<var><a name="index-gdb_002eparse_005fand_005feval-1869"></a></var><br>
|
||
|
|
<blockquote><p>Parse <var>expression</var>, which must be a string, as an expression in
|
||
|
|
the current language, evaluate it, and return the result as a
|
||
|
|
<code>gdb.Value</code>.
|
||
|
|
|
||
|
|
<p>This function can be useful when implementing a new command
|
||
|
|
(see <a href="Commands-In-Python.html#Commands-In-Python">Commands In Python</a>), as it provides a way to parse the
|
||
|
|
command's argument as an expression. It is also useful simply to
|
||
|
|
compute values.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002efind_005fpc_005fline-1870"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.find_pc_line</b> (<var>pc</var>)<var><a name="index-gdb_002efind_005fpc_005fline-1871"></a></var><br>
|
||
|
|
<blockquote><p>Return the <code>gdb.Symtab_and_line</code> object corresponding to the
|
||
|
|
<var>pc</var> value. See <a href="Symbol-Tables-In-Python.html#Symbol-Tables-In-Python">Symbol Tables In Python</a>. If an invalid
|
||
|
|
value of <var>pc</var> is passed as an argument, then the <code>symtab</code> and
|
||
|
|
<code>line</code> attributes of the returned <code>gdb.Symtab_and_line</code> object
|
||
|
|
will be <code>None</code> and 0 respectively. This is identical to
|
||
|
|
<code>gdb.current_progspace().find_pc_line(pc)</code> and is included for
|
||
|
|
historical compatibility.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002epost_005fevent-1872"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.post_event</b> (<var>event</var>)<var><a name="index-gdb_002epost_005fevent-1873"></a></var><br>
|
||
|
|
<blockquote><p>Put <var>event</var>, a callable object taking no arguments, into
|
||
|
|
<span class="sc">gdb</span>'s internal event queue. This callable will be invoked at
|
||
|
|
some later point, during <span class="sc">gdb</span>'s event processing. Events
|
||
|
|
posted using <code>post_event</code> will be run in the order in which they
|
||
|
|
were posted; however, there is no way to know when they will be
|
||
|
|
processed relative to other events inside <span class="sc">gdb</span>.
|
||
|
|
|
||
|
|
<p><span class="sc">gdb</span> is not thread-safe. If your Python program uses multiple
|
||
|
|
threads, you must be careful to only call <span class="sc">gdb</span>-specific
|
||
|
|
functions in the <span class="sc">gdb</span> thread. <code>post_event</code> ensures
|
||
|
|
this. For example:
|
||
|
|
|
||
|
|
<pre class="smallexample"> (gdb) python
|
||
|
|
>import threading
|
||
|
|
>
|
||
|
|
>class Writer():
|
||
|
|
> def __init__(self, message):
|
||
|
|
> self.message = message;
|
||
|
|
> def __call__(self):
|
||
|
|
> gdb.write(self.message)
|
||
|
|
>
|
||
|
|
>class MyThread1 (threading.Thread):
|
||
|
|
> def run (self):
|
||
|
|
> gdb.post_event(Writer("Hello "))
|
||
|
|
>
|
||
|
|
>class MyThread2 (threading.Thread):
|
||
|
|
> def run (self):
|
||
|
|
> gdb.post_event(Writer("World\n"))
|
||
|
|
>
|
||
|
|
>MyThread1().start()
|
||
|
|
>MyThread2().start()
|
||
|
|
>end
|
||
|
|
(gdb) Hello World
|
||
|
|
</pre>
|
||
|
|
</blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002ewrite-1874"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.write</b> (<var>string </var><span class="roman">[</span><var>, stream</var>])<var><a name="index-gdb_002ewrite-1875"></a></var><br>
|
||
|
|
<blockquote><p>Print a string to <span class="sc">gdb</span>'s paginated output stream. The
|
||
|
|
optional <var>stream</var> determines the stream to print to. The default
|
||
|
|
stream is <span class="sc">gdb</span>'s standard output stream. Possible stream
|
||
|
|
values are:
|
||
|
|
|
||
|
|
|
||
|
|
<a name="index-STDOUT-1876"></a>
|
||
|
|
<a name="index-gdb_002eSTDOUT-1877"></a>
|
||
|
|
<dl><dt><code>gdb.STDOUT</code><dd><span class="sc">gdb</span>'s standard output stream.
|
||
|
|
|
||
|
|
<p><a name="index-STDERR-1878"></a><a name="index-gdb_002eSTDERR-1879"></a><br><dt><code>gdb.STDERR</code><dd><span class="sc">gdb</span>'s standard error stream.
|
||
|
|
|
||
|
|
<p><a name="index-STDLOG-1880"></a><a name="index-gdb_002eSTDLOG-1881"></a><br><dt><code>gdb.STDLOG</code><dd><span class="sc">gdb</span>'s log stream (see <a href="Logging-Output.html#Logging-Output">Logging Output</a>).
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>Writing to <code>sys.stdout</code> or <code>sys.stderr</code> will automatically
|
||
|
|
call this function and will automatically direct the output to the
|
||
|
|
relevant stream.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002eflush-1882"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.flush</b> ()<var><a name="index-gdb_002eflush-1883"></a></var><br>
|
||
|
|
<blockquote><p>Flush the buffer of a <span class="sc">gdb</span> paginated stream so that the
|
||
|
|
contents are displayed immediately. <span class="sc">gdb</span> will flush the
|
||
|
|
contents of a stream automatically when it encounters a newline in the
|
||
|
|
buffer. The optional <var>stream</var> determines the stream to flush. The
|
||
|
|
default stream is <span class="sc">gdb</span>'s standard output stream. Possible
|
||
|
|
stream values are:
|
||
|
|
|
||
|
|
|
||
|
|
<a name="index-STDOUT-1884"></a>
|
||
|
|
<a name="index-gdb_002eSTDOUT-1885"></a>
|
||
|
|
<dl><dt><code>gdb.STDOUT</code><dd><span class="sc">gdb</span>'s standard output stream.
|
||
|
|
|
||
|
|
<p><a name="index-STDERR-1886"></a><a name="index-gdb_002eSTDERR-1887"></a><br><dt><code>gdb.STDERR</code><dd><span class="sc">gdb</span>'s standard error stream.
|
||
|
|
|
||
|
|
<p><a name="index-STDLOG-1888"></a><a name="index-gdb_002eSTDLOG-1889"></a><br><dt><code>gdb.STDLOG</code><dd><span class="sc">gdb</span>'s log stream (see <a href="Logging-Output.html#Logging-Output">Logging Output</a>).
|
||
|
|
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<p>Flushing <code>sys.stdout</code> or <code>sys.stderr</code> will automatically
|
||
|
|
call this function for the relevant stream.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002etarget_005fcharset-1890"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.target_charset</b> ()<var><a name="index-gdb_002etarget_005fcharset-1891"></a></var><br>
|
||
|
|
<blockquote><p>Return the name of the current target character set (see <a href="Character-Sets.html#Character-Sets">Character Sets</a>). This differs from <code>gdb.parameter('target-charset')</code> in
|
||
|
|
that ‘<samp><span class="samp">auto</span></samp>’ is never returned.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002etarget_005fwide_005fcharset-1892"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.target_wide_charset</b> ()<var><a name="index-gdb_002etarget_005fwide_005fcharset-1893"></a></var><br>
|
||
|
|
<blockquote><p>Return the name of the current target wide character set
|
||
|
|
(see <a href="Character-Sets.html#Character-Sets">Character Sets</a>). This differs from
|
||
|
|
<code>gdb.parameter('target-wide-charset')</code> in that ‘<samp><span class="samp">auto</span></samp>’ is
|
||
|
|
never returned.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002esolib_005fname-1894"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.solib_name</b> (<var>address</var>)<var><a name="index-gdb_002esolib_005fname-1895"></a></var><br>
|
||
|
|
<blockquote><p>Return the name of the shared library holding the given <var>address</var>
|
||
|
|
as a string, or <code>None</code>. This is identical to
|
||
|
|
<code>gdb.current_progspace().solib_name(address)</code> and is included for
|
||
|
|
historical compatibility.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<p><a name="index-gdb_002edecode_005fline-1896"></a>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.decode_line</b> (<span class="roman">[</span><var>expression</var><span class="roman">]</span>)<var><a name="index-gdb_002edecode_005fline-1897"></a></var><br>
|
||
|
|
<blockquote><p>Return locations of the line specified by <var>expression</var>, or of the
|
||
|
|
current line if no argument was given. This function returns a Python
|
||
|
|
tuple containing two elements. The first element contains a string
|
||
|
|
holding any unparsed section of <var>expression</var> (or <code>None</code> if
|
||
|
|
the expression has been fully parsed). The second element contains
|
||
|
|
either <code>None</code> or another tuple that contains all the locations
|
||
|
|
that match the expression represented as <code>gdb.Symtab_and_line</code>
|
||
|
|
objects (see <a href="Symbol-Tables-In-Python.html#Symbol-Tables-In-Python">Symbol Tables In Python</a>). If <var>expression</var> is
|
||
|
|
provided, it is decoded the way that <span class="sc">gdb</span>'s inbuilt
|
||
|
|
<code>break</code> or <code>edit</code> commands do (see <a href="Specify-Location.html#Specify-Location">Specify Location</a>).
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
<div class="defun">
|
||
|
|
— Function: <b>gdb.prompt_hook</b> (<var>current_prompt</var>)<var><a name="index-gdb_002eprompt_005fhook-1898"></a></var><br>
|
||
|
|
<blockquote><p><a name="prompt_005fhook"></a>If <var>prompt_hook</var> is callable, <span class="sc">gdb</span> will call the method
|
||
|
|
assigned to this operation before a prompt is displayed by
|
||
|
|
<span class="sc">gdb</span>.
|
||
|
|
|
||
|
|
<p>The parameter <code>current_prompt</code> contains the current <span class="sc">gdb</span>
|
||
|
|
prompt. This method must return a Python string, or <code>None</code>. If
|
||
|
|
a string is returned, the <span class="sc">gdb</span> prompt will be set to that
|
||
|
|
string. If <code>None</code> is returned, <span class="sc">gdb</span> will continue to use
|
||
|
|
the current prompt.
|
||
|
|
|
||
|
|
<p>Some prompts cannot be substituted in <span class="sc">gdb</span>. Secondary prompts
|
||
|
|
such as those used by readline for command input, and annotation
|
||
|
|
related prompts are prohibited from being changed.
|
||
|
|
</p></blockquote></div>
|
||
|
|
|
||
|
|
</body></html>
|
||
|
|
|