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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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diff --git a/share/doc/gdb/Parameters-In-Python.html b/share/doc/gdb/Parameters-In-Python.html new file mode 100644 index 0000000..ad5c9a2 --- /dev/null +++ b/share/doc/gdb/Parameters-In-Python.html @@ -0,0 +1,323 @@ +<!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: Parameters In Python</title> + +<meta name="description" content="Debugging with GDB: Parameters In Python"> +<meta name="keywords" content="Debugging with GDB: Parameters 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="Functions-In-Python.html#Functions-In-Python" rel="next" title="Functions In Python"> +<link href="GDB_002fMI-Commands-In-Python.html#GDB_002fMI-Commands-In-Python" rel="previous" title="GDB/MI Commands 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="Parameters-In-Python"></a> +<div class="header"> +<p> +Next: <a href="Functions-In-Python.html#Functions-In-Python" accesskey="n" rel="next">Functions In Python</a>, Previous: <a href="GDB_002fMI-Commands-In-Python.html#GDB_002fMI-Commands-In-Python" accesskey="p" rel="previous">GDB/MI Commands 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="Parameters-In-Python-1"></a> +<h4 class="subsubsection">23.3.2.22 Parameters In Python</h4> + +<a name="index-parameters-in-python"></a> +<a name="index-python-parameters"></a> +<a name="index-gdb_002eParameter"></a> +<a name="index-Parameter"></a> +<p>You can implement new <small>GDB</small> parameters using Python. A new +parameter is implemented as an instance of the <code>gdb.Parameter</code> +class. +</p> +<p>Parameters are exposed to the user via the <code>set</code> and +<code>show</code> commands. See <a href="Help.html#Help">Help</a>. +</p> +<p>There are many parameters that already exist and can be set in +<small>GDB</small>. Two examples are: <code>set follow fork</code> and +<code>set charset</code>. Setting these parameters influences certain +behavior in <small>GDB</small>. Similarly, you can define parameters that +can be used to influence behavior in custom Python scripts and commands. +</p> +<dl> +<dt><a name="index-Parameter_002e_005f_005finit_005f_005f"></a>Function: <strong>Parameter.__init__</strong> <em>(name, <var>command-class</var>, <var>parameter-class</var> <span class="roman">[</span>, <var>enum-sequence</var><span class="roman">]</span>)</em></dt> +<dd><p>The object initializer for <code>Parameter</code> registers the new +parameter with <small>GDB</small>. This initializer is normally invoked +from the subclass’ own <code>__init__</code> method. +</p> +<p><var>name</var> is the name of the new parameter. If <var>name</var> consists +of multiple words, then the initial words are looked for as prefix +parameters. An example of this can be illustrated with the +<code>set print</code> set of parameters. If <var>name</var> is +<code>print foo</code>, then <code>print</code> will be searched as the prefix +parameter. In this case the parameter can subsequently be accessed in +<small>GDB</small> as <code>set print foo</code>. +</p> +<p>If <var>name</var> consists of multiple words, and no prefix parameter group +can be found, an exception is raised. +</p> +<p><var>command-class</var> should be one of the ‘<samp>COMMAND_</samp>’ constants +(see <a href="CLI-Commands-In-Python.html#CLI-Commands-In-Python">CLI Commands In Python</a>). This argument tells <small>GDB</small> how to +categorize the new parameter in the help system. +</p> +<p><var>parameter-class</var> should be one of the ‘<samp>PARAM_</samp>’ constants +defined below. This argument tells <small>GDB</small> the type of the new +parameter; this information is used for input validation and +completion. +</p> +<p>If <var>parameter-class</var> is <code>PARAM_ENUM</code>, then +<var>enum-sequence</var> must be a sequence of strings. These strings +represent the possible values for the parameter. +</p> +<p>If <var>parameter-class</var> is not <code>PARAM_ENUM</code>, then the presence +of a fourth argument will cause an exception to be thrown. +</p> +<p>The help text for the new parameter includes the Python documentation +string from the parameter’s class, if there is one. If there is no +documentation string, a default value is used. The documentation +string is included in the output of the parameters <code>help set</code> and +<code>help show</code> commands, and should be written taking this into +account. +</p></dd></dl> + +<dl> +<dt><a name="index-Parameter_002eset_005fdoc"></a>Variable: <strong>Parameter.set_doc</strong></dt> +<dd><p>If this attribute exists, and is a string, then its value is used as +the first part of the help text for this parameter’s <code>set</code> +command. The second part of the help text is taken from the +documentation string for the parameter’s class, if there is one. +</p> +<p>The value of <code>set_doc</code> should give a brief summary specific to +the set action, this text is only displayed when the user runs the +<code>help set</code> command for this parameter. The class documentation +should be used to give a fuller description of what the parameter +does, this text is displayed for both the <code>help set</code> and +<code>help show</code> commands. +</p> +<p>The <code>set_doc</code> value is examined when <code>Parameter.__init__</code> is +invoked; subsequent changes have no effect. +</p></dd></dl> + +<dl> +<dt><a name="index-Parameter_002eshow_005fdoc"></a>Variable: <strong>Parameter.show_doc</strong></dt> +<dd><p>If this attribute exists, and is a string, then its value is used as +the first part of the help text for this parameter’s <code>show</code> +command. The second part of the help text is taken from the +documentation string for the parameter’s class, if there is one. +</p> +<p>The value of <code>show_doc</code> should give a brief summary specific to +the show action, this text is only displayed when the user runs the +<code>help show</code> command for this parameter. The class documentation +should be used to give a fuller description of what the parameter +does, this text is displayed for both the <code>help set</code> and +<code>help show</code> commands. +</p> +<p>The <code>show_doc</code> value is examined when <code>Parameter.__init__</code> +is invoked; subsequent changes have no effect. +</p></dd></dl> + +<dl> +<dt><a name="index-Parameter_002evalue"></a>Variable: <strong>Parameter.value</strong></dt> +<dd><p>The <code>value</code> attribute holds the underlying value of the +parameter. It can be read and assigned to just as any other +attribute. <small>GDB</small> does validation when assignments are made. +</p></dd></dl> + +<p>There are two methods that may be implemented in any <code>Parameter</code> +class. These are: +</p> +<dl> +<dt><a name="index-Parameter_002eget_005fset_005fstring"></a>Function: <strong>Parameter.get_set_string</strong> <em>(self)</em></dt> +<dd><p>If this method exists, <small>GDB</small> will call it when a +<var>parameter</var>’s value has been changed via the <code>set</code> API (for +example, <kbd>set foo off</kbd>). The <code>value</code> attribute has already +been populated with the new value and may be used in output. This +method must return a string. If the returned string is not empty, +<small>GDB</small> will present it to the user. +</p> +<p>If this method raises the <code>gdb.GdbError</code> exception +(see <a href="Exception-Handling.html#Exception-Handling">Exception Handling</a>), then <small>GDB</small> will print the +exception’s string and the <code>set</code> command will fail. Note, +however, that the <code>value</code> attribute will not be reset in this +case. So, if your parameter must validate values, it should store the +old value internally and reset the exposed value, like so: +</p> +<div class="smallexample"> +<pre class="smallexample">class ExampleParam (gdb.Parameter): + def __init__ (self, name): + super (ExampleParam, self).__init__ (name, + gdb.COMMAND_DATA, + gdb.PARAM_BOOLEAN) + self.value = True + self.saved_value = True + def validate(self): + return False + def get_set_string (self): + if not self.validate(): + self.value = self.saved_value + raise gdb.GdbError('Failed to validate') + self.saved_value = self.value + return "" +</pre></div> +</dd></dl> + +<dl> +<dt><a name="index-Parameter_002eget_005fshow_005fstring"></a>Function: <strong>Parameter.get_show_string</strong> <em>(self, svalue)</em></dt> +<dd><p><small>GDB</small> will call this method when a <var>parameter</var>’s +<code>show</code> API has been invoked (for example, <kbd>show foo</kbd>). The +argument <code>svalue</code> receives the string representation of the +current value. This method must return a string. +</p></dd></dl> + +<p>When a new parameter is defined, its type must be specified. The +available types are represented by constants defined in the <code>gdb</code> +module: +</p> +<dl compact="compact"> +<dd><a name="index-PARAM_005fBOOLEAN"></a> +<a name="index-gdb_002ePARAM_005fBOOLEAN"></a> +</dd> +<dt><code>gdb.PARAM_BOOLEAN</code></dt> +<dd><p>The value is a plain boolean. The Python boolean values, <code>True</code> +and <code>False</code> are the only valid values. +</p> +<a name="index-PARAM_005fAUTO_005fBOOLEAN"></a> +<a name="index-gdb_002ePARAM_005fAUTO_005fBOOLEAN"></a> +</dd> +<dt><code>gdb.PARAM_AUTO_BOOLEAN</code></dt> +<dd><p>The value has three possible states: true, false, and ‘<samp>auto</samp>’. In +Python, true and false are represented using boolean constants, and +‘<samp>auto</samp>’ is represented using <code>None</code>. +</p> +<a name="index-PARAM_005fUINTEGER"></a> +<a name="index-gdb_002ePARAM_005fUINTEGER"></a> +</dd> +<dt><code>gdb.PARAM_UINTEGER</code></dt> +<dd><p>The value is an unsigned integer. The value of 0 should be +interpreted to mean “unlimited”. +</p> +<a name="index-PARAM_005fINTEGER"></a> +<a name="index-gdb_002ePARAM_005fINTEGER"></a> +</dd> +<dt><code>gdb.PARAM_INTEGER</code></dt> +<dd><p>The value is a signed integer. The value of 0 should be interpreted +to mean “unlimited”. +</p> +<a name="index-PARAM_005fSTRING"></a> +<a name="index-gdb_002ePARAM_005fSTRING"></a> +</dd> +<dt><code>gdb.PARAM_STRING</code></dt> +<dd><p>The value is a string. When the user modifies the string, any escape +sequences, such as ‘<samp>\t</samp>’, ‘<samp>\f</samp>’, and octal escapes, are +translated into corresponding characters and encoded into the current +host charset. +</p> +<a name="index-PARAM_005fSTRING_005fNOESCAPE"></a> +<a name="index-gdb_002ePARAM_005fSTRING_005fNOESCAPE"></a> +</dd> +<dt><code>gdb.PARAM_STRING_NOESCAPE</code></dt> +<dd><p>The value is a string. When the user modifies the string, escapes are +passed through untranslated. +</p> +<a name="index-PARAM_005fOPTIONAL_005fFILENAME"></a> +<a name="index-gdb_002ePARAM_005fOPTIONAL_005fFILENAME"></a> +</dd> +<dt><code>gdb.PARAM_OPTIONAL_FILENAME</code></dt> +<dd><p>The value is a either a filename (a string), or <code>None</code>. +</p> +<a name="index-PARAM_005fFILENAME"></a> +<a name="index-gdb_002ePARAM_005fFILENAME"></a> +</dd> +<dt><code>gdb.PARAM_FILENAME</code></dt> +<dd><p>The value is a filename. This is just like +<code>PARAM_STRING_NOESCAPE</code>, but uses file names for completion. +</p> +<a name="index-PARAM_005fZINTEGER"></a> +<a name="index-gdb_002ePARAM_005fZINTEGER"></a> +</dd> +<dt><code>gdb.PARAM_ZINTEGER</code></dt> +<dd><p>The value is an integer. This is like <code>PARAM_INTEGER</code>, except 0 +is interpreted as itself. +</p> +<a name="index-PARAM_005fZUINTEGER"></a> +<a name="index-gdb_002ePARAM_005fZUINTEGER"></a> +</dd> +<dt><code>gdb.PARAM_ZUINTEGER</code></dt> +<dd><p>The value is an unsigned integer. This is like <code>PARAM_INTEGER</code>, +except 0 is interpreted as itself, and the value cannot be negative. +</p> +<a name="index-PARAM_005fZUINTEGER_005fUNLIMITED"></a> +<a name="index-gdb_002ePARAM_005fZUINTEGER_005fUNLIMITED"></a> +</dd> +<dt><code>gdb.PARAM_ZUINTEGER_UNLIMITED</code></dt> +<dd><p>The value is a signed integer. This is like <code>PARAM_ZUINTEGER</code>, +except the special value -1 should be interpreted to mean +“unlimited”. Other negative values are not allowed. +</p> +<a name="index-PARAM_005fENUM"></a> +<a name="index-gdb_002ePARAM_005fENUM"></a> +</dd> +<dt><code>gdb.PARAM_ENUM</code></dt> +<dd><p>The value is a string, which must be one of a collection string +constants provided when the parameter is created. +</p></dd> +</dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Functions-In-Python.html#Functions-In-Python" accesskey="n" rel="next">Functions In Python</a>, Previous: <a href="GDB_002fMI-Commands-In-Python.html#GDB_002fMI-Commands-In-Python" accesskey="p" rel="previous">GDB/MI Commands 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> |