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diff --git a/share/doc/gdb/Functions-In-Python.html b/share/doc/gdb/Functions-In-Python.html new file mode 100644 index 0000000..96ba5c5 --- /dev/null +++ b/share/doc/gdb/Functions-In-Python.html @@ -0,0 +1,147 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with the +Invariant Sections being "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Functions In Python</title> + +<meta name="description" content="Debugging with GDB: Functions In Python"> +<meta name="keywords" content="Debugging with GDB: Functions In Python"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Python-API.html#Python-API" rel="up" title="Python API"> +<link href="Progspaces-In-Python.html#Progspaces-In-Python" rel="next" title="Progspaces In Python"> +<link href="Parameters-In-Python.html#Parameters-In-Python" rel="previous" title="Parameters In Python"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Functions-In-Python"></a> +<div class="header"> +<p> +Next: <a href="Progspaces-In-Python.html#Progspaces-In-Python" accesskey="n" rel="next">Progspaces In Python</a>, Previous: <a href="Parameters-In-Python.html#Parameters-In-Python" accesskey="p" rel="previous">Parameters In Python</a>, Up: <a href="Python-API.html#Python-API" accesskey="u" rel="up">Python API</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Writing-new-convenience-functions"></a> +<h4 class="subsubsection">23.3.2.23 Writing new convenience functions</h4> + +<a name="index-writing-convenience-functions"></a> +<a name="index-convenience-functions-in-python"></a> +<a name="index-python-convenience-functions"></a> +<a name="index-gdb_002eFunction"></a> +<a name="index-Function"></a> +<p>You can implement new convenience functions (see <a href="Convenience-Vars.html#Convenience-Vars">Convenience Vars</a>) +in Python. A convenience function is an instance of a subclass of the +class <code>gdb.Function</code>. +</p> +<dl> +<dt><a name="index-Function_002e_005f_005finit_005f_005f"></a>Function: <strong>Function.__init__</strong> <em>(name)</em></dt> +<dd><p>The initializer for <code>Function</code> registers the new function with +<small>GDB</small>. The argument <var>name</var> is the name of the function, +a string. The function will be visible to the user as a convenience +variable of type <code>internal function</code>, whose name is the same as +the given <var>name</var>. +</p> +<p>The documentation for the new function is taken from the documentation +string for the new class. +</p></dd></dl> + +<dl> +<dt><a name="index-Function_002einvoke"></a>Function: <strong>Function.invoke</strong> <em>(<var>*args</var>)</em></dt> +<dd><p>When a convenience function is evaluated, its arguments are converted +to instances of <code>gdb.Value</code>, and then the function’s +<code>invoke</code> method is called. Note that <small>GDB</small> does not +predetermine the arity of convenience functions. Instead, all +available arguments are passed to <code>invoke</code>, following the +standard Python calling convention. In particular, a convenience +function can have default values for parameters without ill effect. +</p> +<p>The return value of this method is used as its value in the enclosing +expression. If an ordinary Python value is returned, it is converted +to a <code>gdb.Value</code> following the usual rules. +</p></dd></dl> + +<p>The following code snippet shows how a trivial convenience function can +be implemented in Python: +</p> +<div class="smallexample"> +<pre class="smallexample">class Greet (gdb.Function): + """Return string to greet someone. +Takes a name as argument.""" + + def __init__ (self): + super (Greet, self).__init__ ("greet") + + def invoke (self, name): + return "Hello, %s!" % name.string () + +Greet () +</pre></div> + +<p>The last line instantiates the class, and is necessary to trigger the +registration of the function with <small>GDB</small>. Depending on how the +Python code is read into <small>GDB</small>, you may need to import the +<code>gdb</code> module explicitly. +</p> +<p>Now you can use the function in an expression: +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) print $greet("Bob") +$1 = "Hello, Bob!" +</pre></div> + +<hr> +<div class="header"> +<p> +Next: <a href="Progspaces-In-Python.html#Progspaces-In-Python" accesskey="n" rel="next">Progspaces In Python</a>, Previous: <a href="Parameters-In-Python.html#Parameters-In-Python" accesskey="p" rel="previous">Parameters In Python</a>, Up: <a href="Python-API.html#Python-API" accesskey="u" rel="up">Python API</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |