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diff --git a/share/doc/gccint/Plugin-API.html b/share/doc/gccint/Plugin-API.html new file mode 100644 index 0000000..3b7c263 --- /dev/null +++ b/share/doc/gccint/Plugin-API.html @@ -0,0 +1,295 @@ +<!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 "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + +A GNU Manual + +(b) The FSF's Back-Cover Text is: + +You have freedom to copy and modify this GNU Manual, like GNU + software. Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>GNU Compiler Collection (GCC) Internals: Plugin API</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Plugin API"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Plugin API"> +<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="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Plugins.html#Plugins" rel="up" title="Plugins"> +<link href="Plugins-pass.html#Plugins-pass" rel="next" title="Plugins pass"> +<link href="Plugins-loading.html#Plugins-loading" rel="previous" title="Plugins loading"> +<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="Plugin-API"></a> +<div class="header"> +<p> +Next: <a href="Plugins-pass.html#Plugins-pass" accesskey="n" rel="next">Plugins pass</a>, Previous: <a href="Plugins-loading.html#Plugins-loading" accesskey="p" rel="previous">Plugins loading</a>, Up: <a href="Plugins.html#Plugins" accesskey="u" rel="up">Plugins</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Plugin-API-1"></a> +<h3 class="section">24.2 Plugin API</h3> + +<p>Plugins are activated by the compiler at specific events as defined in +<samp>gcc-plugin.h</samp>. For each event of interest, the plugin should +call <code>register_callback</code> specifying the name of the event and +address of the callback function that will handle that event. +</p> +<p>The header <samp>gcc-plugin.h</samp> must be the first gcc header to be included. +</p> +<a name="Plugin-license-check"></a> +<h4 class="subsection">24.2.1 Plugin license check</h4> + +<p>Every plugin should define the global symbol <code>plugin_is_GPL_compatible</code> +to assert that it has been licensed under a GPL-compatible license. +If this symbol does not exist, the compiler will emit a fatal error +and exit with the error message: +</p> +<div class="smallexample"> +<pre class="smallexample">fatal error: plugin <var>name</var> is not licensed under a GPL-compatible license +<var>name</var>: undefined symbol: plugin_is_GPL_compatible +compilation terminated +</pre></div> + +<p>The declared type of the symbol should be int, to match a forward declaration +in <samp>gcc-plugin.h</samp> that suppresses C++ mangling. It does not need to be in +any allocated section, though. The compiler merely asserts that +the symbol exists in the global scope. Something like this is enough: +</p> +<div class="smallexample"> +<pre class="smallexample">int plugin_is_GPL_compatible; +</pre></div> + +<a name="Plugin-initialization"></a> +<h4 class="subsection">24.2.2 Plugin initialization</h4> + +<p>Every plugin should export a function called <code>plugin_init</code> that +is called right after the plugin is loaded. This function is +responsible for registering all the callbacks required by the plugin +and do any other required initialization. +</p> +<p>This function is called from <code>compile_file</code> right before invoking +the parser. The arguments to <code>plugin_init</code> are: +</p> +<ul> +<li> <code>plugin_info</code>: Plugin invocation information. +</li><li> <code>version</code>: GCC version. +</li></ul> + +<p>The <code>plugin_info</code> struct is defined as follows: +</p> +<div class="smallexample"> +<pre class="smallexample">struct plugin_name_args +{ + char *base_name; /* Short name of the plugin + (filename without .so suffix). */ + const char *full_name; /* Path to the plugin as specified with + -fplugin=. */ + int argc; /* Number of arguments specified with + -fplugin-arg-.... */ + struct plugin_argument *argv; /* Array of ARGC key-value pairs. */ + const char *version; /* Version string provided by plugin. */ + const char *help; /* Help string provided by plugin. */ +} +</pre></div> + +<p>If initialization fails, <code>plugin_init</code> must return a non-zero +value. Otherwise, it should return 0. +</p> +<p>The version of the GCC compiler loading the plugin is described by the +following structure: +</p> +<div class="smallexample"> +<pre class="smallexample">struct plugin_gcc_version +{ + const char *basever; + const char *datestamp; + const char *devphase; + const char *revision; + const char *configuration_arguments; +}; +</pre></div> + +<p>The function <code>plugin_default_version_check</code> takes two pointers to +such structure and compare them field by field. It can be used by the +plugin’s <code>plugin_init</code> function. +</p> +<p>The version of GCC used to compile the plugin can be found in the symbol +<code>gcc_version</code> defined in the header <samp>plugin-version.h</samp>. The +recommended version check to perform looks like +</p> +<div class="smallexample"> +<pre class="smallexample">#include "plugin-version.h" +... + +int +plugin_init (struct plugin_name_args *plugin_info, + struct plugin_gcc_version *version) +{ + if (!plugin_default_version_check (version, &gcc_version)) + return 1; + +} +</pre></div> + +<p>but you can also check the individual fields if you want a less strict check. +</p> +<a name="Plugin-callbacks"></a> +<h4 class="subsection">24.2.3 Plugin callbacks</h4> + +<p>Callback functions have the following prototype: +</p> +<div class="smallexample"> +<pre class="smallexample">/* The prototype for a plugin callback function. + gcc_data - event-specific data provided by GCC + user_data - plugin-specific data provided by the plug-in. */ +typedef void (*plugin_callback_func)(void *gcc_data, void *user_data); +</pre></div> + +<p>Callbacks can be invoked at the following pre-determined events: +</p> + +<div class="smallexample"> +<pre class="smallexample">enum plugin_event +{ + PLUGIN_START_PARSE_FUNCTION, /* Called before parsing the body of a function. */ + PLUGIN_FINISH_PARSE_FUNCTION, /* After finishing parsing a function. */ + PLUGIN_PASS_MANAGER_SETUP, /* To hook into pass manager. */ + PLUGIN_FINISH_TYPE, /* After finishing parsing a type. */ + PLUGIN_FINISH_DECL, /* After finishing parsing a declaration. */ + PLUGIN_FINISH_UNIT, /* Useful for summary processing. */ + PLUGIN_PRE_GENERICIZE, /* Allows to see low level AST in C and C++ frontends. */ + PLUGIN_FINISH, /* Called before GCC exits. */ + PLUGIN_INFO, /* Information about the plugin. */ + PLUGIN_GGC_START, /* Called at start of GCC Garbage Collection. */ + PLUGIN_GGC_MARKING, /* Extend the GGC marking. */ + PLUGIN_GGC_END, /* Called at end of GGC. */ + PLUGIN_REGISTER_GGC_ROOTS, /* Register an extra GGC root table. */ + PLUGIN_ATTRIBUTES, /* Called during attribute registration */ + PLUGIN_START_UNIT, /* Called before processing a translation unit. */ + PLUGIN_PRAGMAS, /* Called during pragma registration. */ + /* Called before first pass from all_passes. */ + PLUGIN_ALL_PASSES_START, + /* Called after last pass from all_passes. */ + PLUGIN_ALL_PASSES_END, + /* Called before first ipa pass. */ + PLUGIN_ALL_IPA_PASSES_START, + /* Called after last ipa pass. */ + PLUGIN_ALL_IPA_PASSES_END, + /* Allows to override pass gate decision for current_pass. */ + PLUGIN_OVERRIDE_GATE, + /* Called before executing a pass. */ + PLUGIN_PASS_EXECUTION, + /* Called before executing subpasses of a GIMPLE_PASS in + execute_ipa_pass_list. */ + PLUGIN_EARLY_GIMPLE_PASSES_START, + /* Called after executing subpasses of a GIMPLE_PASS in + execute_ipa_pass_list. */ + PLUGIN_EARLY_GIMPLE_PASSES_END, + /* Called when a pass is first instantiated. */ + PLUGIN_NEW_PASS, +/* Called when a file is #include-d or given via the #line directive. + This could happen many times. The event data is the included file path, + as a const char* pointer. */ + PLUGIN_INCLUDE_FILE, + + /* Called when -fanalyzer starts. The event data is an + ana::plugin_analyzer_init_iface *. */ + PLUGIN_ANALYZER_INIT, + + PLUGIN_EVENT_FIRST_DYNAMIC /* Dummy event used for indexing callback + array. */ +}; +</pre></div> + +<p>In addition, plugins can also look up the enumerator of a named event, +and / or generate new events dynamically, by calling the function +<code>get_named_event_id</code>. +</p> +<p>To register a callback, the plugin calls <code>register_callback</code> with +the arguments: +</p> +<ul> +<li> <code>char *name</code>: Plugin name. +</li><li> <code>int event</code>: The event code. +</li><li> <code>plugin_callback_func callback</code>: The function that handles <code>event</code>. +</li><li> <code>void *user_data</code>: Pointer to plugin-specific data. +</li></ul> + +<p>For the <i>PLUGIN_PASS_MANAGER_SETUP</i>, <i>PLUGIN_INFO</i>, and +<i>PLUGIN_REGISTER_GGC_ROOTS</i> pseudo-events the <code>callback</code> should be null, +and the <code>user_data</code> is specific. +</p> +<p>When the <i>PLUGIN_PRAGMAS</i> event is triggered (with a null pointer as +data from GCC), plugins may register their own pragmas. Notice that +pragmas are not available from <samp>lto1</samp>, so plugins used with +<code>-flto</code> option to GCC during link-time optimization cannot use +pragmas and do not even see functions like <code>c_register_pragma</code> or +<code>pragma_lex</code>. +</p> +<p>The <i>PLUGIN_INCLUDE_FILE</i> event, with a <code>const char*</code> file path as +GCC data, is triggered for processing of <code>#include</code> or +<code>#line</code> directives. +</p> +<p>The <i>PLUGIN_FINISH</i> event is the last time that plugins can call GCC +functions, notably emit diagnostics with <code>warning</code>, <code>error</code> +etc. +</p> + +<hr> +<div class="header"> +<p> +Next: <a href="Plugins-pass.html#Plugins-pass" accesskey="n" rel="next">Plugins pass</a>, Previous: <a href="Plugins-loading.html#Plugins-loading" accesskey="p" rel="previous">Plugins loading</a>, Up: <a href="Plugins.html#Plugins" accesskey="u" rel="up">Plugins</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |