aarch64-linux-gnu-4.9/share/doc/gccint/PCH-Target.html - toolchains/linux-x86/gcc - Git at Google

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <!-- 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. -->
 <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
 <head>
 <title>GNU Compiler Collection (GCC) Internals: PCH Target</title>

 <meta name="description" content="GNU Compiler Collection (GCC) Internals: PCH Target">
 <meta name="keywords" content="GNU Compiler Collection (GCC) Internals: PCH Target">
 <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="Target-Macros.html#Target-Macros" rel="up" title="Target Macros">
 <link href="C_002b_002b-ABI.html#C_002b_002b-ABI" rel="next" title="C++ ABI">
 <link href="MIPS-Coprocessors.html#MIPS-Coprocessors" rel="prev" title="MIPS Coprocessors">
 <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="PCH-Target"></a>
 <div class="header">
 <p>
 Next: <a href="C_002b_002b-ABI.html#C_002b_002b-ABI" accesskey="n" rel="next">C++ ABI</a>, Previous: <a href="MIPS-Coprocessors.html#MIPS-Coprocessors" accesskey="p" rel="prev">MIPS Coprocessors</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</a> &nbsp; [<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="Parameters-for-Precompiled-Header-Validity-Checking"></a>
 <h3 class="section">17.28 Parameters for Precompiled Header Validity Checking</h3>
 <a name="index-parameters_002c-precompiled-headers"></a>

 <dl>
 <dt><a name="index-TARGET_005fGET_005fPCH_005fVALIDITY"></a>Target Hook: <em>void *</em> <strong>TARGET_GET_PCH_VALIDITY</strong> <em>(size_t *<var>sz</var>)</em></dt>
 <dd><p>This hook returns a pointer to the data needed by
 <code>TARGET_PCH_VALID_P</code> and sets
 &lsquo;<samp>*<var>sz</var></samp>&rsquo; to the size of the data in bytes.
 </p></dd></dl>

 <dl>
 <dt><a name="index-TARGET_005fPCH_005fVALID_005fP"></a>Target Hook: <em>const char *</em> <strong>TARGET_PCH_VALID_P</strong> <em>(const void *<var>data</var>, size_t <var>sz</var>)</em></dt>
 <dd><p>This hook checks whether the options used to create a PCH file are
 compatible with the current settings.  It returns <code>NULL</code>
 if so and a suitable error message if not.  Error messages will
 be presented to the user and must be localized using &lsquo;<samp>_(<var>msg</var>)</samp>&rsquo;.
 </p>
 <p><var>data</var> is the data that was returned by <code>TARGET_GET_PCH_VALIDITY</code>
 when the PCH file was created and <var>sz</var> is the size of that data in bytes.
 It&rsquo;s safe to assume that the data was created by the same version of the
 compiler, so no format checking is needed.
 </p>
 <p>The default definition of <code>default_pch_valid_p</code> should be
 suitable for most targets.
 </p></dd></dl>

 <dl>
 <dt><a name="index-TARGET_005fCHECK_005fPCH_005fTARGET_005fFLAGS"></a>Target Hook: <em>const char *</em> <strong>TARGET_CHECK_PCH_TARGET_FLAGS</strong> <em>(int <var>pch_flags</var>)</em></dt>
 <dd><p>If this hook is nonnull, the default implementation of
 <code>TARGET_PCH_VALID_P</code> will use it to check for compatible values
 of <code>target_flags</code>.  <var>pch_flags</var> specifies the value that
 <code>target_flags</code> had when the PCH file was created.  The return
 value is the same as for <code>TARGET_PCH_VALID_P</code>.
 </p></dd></dl>

 <dl>
 <dt><a name="index-TARGET_005fPREPARE_005fPCH_005fSAVE"></a>Target Hook: <em>void</em> <strong>TARGET_PREPARE_PCH_SAVE</strong> <em>(void)</em></dt>
 <dd><p>Called before writing out a PCH file.  If the target has some
 garbage-collected data that needs to be in a particular state on PCH loads,
 it can use this hook to enforce that state.  Very few targets need
 to do anything here.
 </p></dd></dl>

 <hr>
 <div class="header">
 <p>
 Next: <a href="C_002b_002b-ABI.html#C_002b_002b-ABI" accesskey="n" rel="next">C++ ABI</a>, Previous: <a href="MIPS-Coprocessors.html#MIPS-Coprocessors" accesskey="p" rel="prev">MIPS Coprocessors</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</a> &nbsp; [<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>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
	<html>
	<!-- 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. -->
	<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
	<head>
	<title>GNU Compiler Collection (GCC) Internals: PCH Target</title>

	<meta name="description" content="GNU Compiler Collection (GCC) Internals: PCH Target">
	<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: PCH Target">
	<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="Target-Macros.html#Target-Macros" rel="up" title="Target Macros">
	<link href="C_002b_002b-ABI.html#C_002b_002b-ABI" rel="next" title="C++ ABI">
	<link href="MIPS-Coprocessors.html#MIPS-Coprocessors" rel="prev" title="MIPS Coprocessors">
	<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="PCH-Target"></a>
	<div class="header">
	<p>
	Next: <a href="C_002b_002b-ABI.html#C_002b_002b-ABI" accesskey="n" rel="next">C++ ABI</a>, Previous: <a href="MIPS-Coprocessors.html#MIPS-Coprocessors" accesskey="p" rel="prev">MIPS Coprocessors</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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="Parameters-for-Precompiled-Header-Validity-Checking"></a>
	<h3 class="section">17.28 Parameters for Precompiled Header Validity Checking</h3>
	<a name="index-parameters_002c-precompiled-headers"></a>

	<dl>
	<dt><a name="index-TARGET_005fGET_005fPCH_005fVALIDITY"></a>Target Hook: <em>void </em> <strong>TARGET_GET_PCH_VALIDITY</strong> <em>(size_t <var>sz</var>)</em></dt>
	<dd><p>This hook returns a pointer to the data needed by
	<code>TARGET_PCH_VALID_P</code> and sets
	‘<samp>*<var>sz</var></samp>’ to the size of the data in bytes.
	</p></dd></dl>

	<dl>
	<dt><a name="index-TARGET_005fPCH_005fVALID_005fP"></a>Target Hook: <em>const char </em> <strong>TARGET_PCH_VALID_P</strong> <em>(const void <var>data</var>, size_t <var>sz</var>)</em></dt>
	<dd><p>This hook checks whether the options used to create a PCH file are
	compatible with the current settings. It returns <code>NULL</code>
	if so and a suitable error message if not. Error messages will
	be presented to the user and must be localized using ‘<samp>_(<var>msg</var>)</samp>’.
	</p>
	<p><var>data</var> is the data that was returned by <code>TARGET_GET_PCH_VALIDITY</code>
	when the PCH file was created and <var>sz</var> is the size of that data in bytes.
	It’s safe to assume that the data was created by the same version of the
	compiler, so no format checking is needed.
	</p>
	<p>The default definition of <code>default_pch_valid_p</code> should be
	suitable for most targets.
	</p></dd></dl>

	<dl>
	<dt><a name="index-TARGET_005fCHECK_005fPCH_005fTARGET_005fFLAGS"></a>Target Hook: <em>const char *</em> <strong>TARGET_CHECK_PCH_TARGET_FLAGS</strong> <em>(int <var>pch_flags</var>)</em></dt>
	<dd><p>If this hook is nonnull, the default implementation of
	<code>TARGET_PCH_VALID_P</code> will use it to check for compatible values
	of <code>target_flags</code>. <var>pch_flags</var> specifies the value that
	<code>target_flags</code> had when the PCH file was created. The return
	value is the same as for <code>TARGET_PCH_VALID_P</code>.
	</p></dd></dl>

	<dl>
	<dt><a name="index-TARGET_005fPREPARE_005fPCH_005fSAVE"></a>Target Hook: <em>void</em> <strong>TARGET_PREPARE_PCH_SAVE</strong> <em>(void)</em></dt>
	<dd><p>Called before writing out a PCH file. If the target has some
	garbage-collected data that needs to be in a particular state on PCH loads,
	it can use this hook to enforce that state. Very few targets need
	to do anything here.
	</p></dd></dl>

	<hr>
	<div class="header">
	<p>
	Next: <a href="C_002b_002b-ABI.html#C_002b_002b-ABI" accesskey="n" rel="next">C++ ABI</a>, Previous: <a href="MIPS-Coprocessors.html#MIPS-Coprocessors" accesskey="p" rel="prev">MIPS Coprocessors</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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>