<html lang="en">
<head>
<title>Plugins pass - GNU Compiler Collection (GCC) Internals</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Compiler Collection (GCC) Internals">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Plugins.html#Plugins" title="Plugins">
<link rel="prev" href="Plugin-API.html#Plugin-API" title="Plugin API">
<link rel="next" href="Plugins-GC.html#Plugins-GC" title="Plugins GC">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1988-2015 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.-->
<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="Plugins-pass"></a>
<p>
Next: <a rel="next" accesskey="n" href="Plugins-GC.html#Plugins-GC">Plugins GC</a>,
Previous: <a rel="previous" accesskey="p" href="Plugin-API.html#Plugin-API">Plugin API</a>,
Up: <a rel="up" accesskey="u" href="Plugins.html#Plugins">Plugins</a>
<hr>
</div>
<h3 class="section">23.3 Interacting with the pass manager</h3>
<p>There needs to be a way to add/reorder/remove passes dynamically. This
is useful for both analysis plugins (plugging in after a certain pass
such as CFG or an IPA pass) and optimization plugins.
<p>Basic support for inserting new passes or replacing existing passes is
provided. A plugin registers a new pass with GCC by calling
<code>register_callback</code> with the <code>PLUGIN_PASS_MANAGER_SETUP</code>
event and a pointer to a <code>struct register_pass_info</code> object defined as follows
<pre class="smallexample"> enum pass_positioning_ops
{
PASS_POS_INSERT_AFTER, // Insert after the reference pass.
PASS_POS_INSERT_BEFORE, // Insert before the reference pass.
PASS_POS_REPLACE // Replace the reference pass.
};
struct register_pass_info
{
struct opt_pass *pass; /* New pass provided by the plugin. */
const char *reference_pass_name; /* Name of the reference pass for hooking
up the new pass. */
int ref_pass_instance_number; /* Insert the pass at the specified
instance number of the reference pass. */
/* Do it for every instance if it is 0. */
enum pass_positioning_ops pos_op; /* how to insert the new pass. */
};
/* Sample plugin code that registers a new pass. */
int
plugin_init (struct plugin_name_args *plugin_info,
struct plugin_gcc_version *version)
{
struct register_pass_info pass_info;
...
/* Code to fill in the pass_info object with new pass information. */
...
/* Register the new pass. */
register_callback (plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &pass_info);
...
}
</pre>
</body></html>