1<html lang="en"> 2<head> 3<title>Push/Pop Macro Pragmas - Using the GNU Compiler Collection (GCC)</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Using the GNU Compiler Collection (GCC)"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Pragmas.html#Pragmas" title="Pragmas"> 9<link rel="prev" href="Visibility-Pragmas.html#Visibility-Pragmas" title="Visibility Pragmas"> 10<link rel="next" href="Function-Specific-Option-Pragmas.html#Function-Specific-Option-Pragmas" title="Function Specific Option Pragmas"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<!-- 13Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 141998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 152010 Free Software Foundation, Inc. 16 17Permission is granted to copy, distribute and/or modify this document 18under the terms of the GNU Free Documentation License, Version 1.3 or 19any later version published by the Free Software Foundation; with the 20Invariant Sections being ``Funding Free Software'', the Front-Cover 21Texts being (a) (see below), and with the Back-Cover Texts being (b) 22(see below). A copy of the license is included in the section entitled 23``GNU Free Documentation License''. 24 25(a) The FSF's Front-Cover Text is: 26 27 A GNU Manual 28 29(b) The FSF's Back-Cover Text is: 30 31 You have freedom to copy and modify this GNU Manual, like GNU 32 software. Copies published by the Free Software Foundation raise 33 funds for GNU development.--> 34<meta http-equiv="Content-Style-Type" content="text/css"> 35<style type="text/css"><!-- 36 pre.display { font-family:inherit } 37 pre.format { font-family:inherit } 38 pre.smalldisplay { font-family:inherit; font-size:smaller } 39 pre.smallformat { font-family:inherit; font-size:smaller } 40 pre.smallexample { font-size:smaller } 41 pre.smalllisp { font-size:smaller } 42 span.sc { font-variant:small-caps } 43 span.roman { font-family:serif; font-weight:normal; } 44 span.sansserif { font-family:sans-serif; font-weight:normal; } 45--></style> 46<link rel="stylesheet" type="text/css" href="../cs.css"> 47</head> 48<body> 49<div class="node"> 50<a name="Push%2fPop-Macro-Pragmas"></a> 51<a name="Push_002fPop-Macro-Pragmas"></a> 52<p> 53Next: <a rel="next" accesskey="n" href="Function-Specific-Option-Pragmas.html#Function-Specific-Option-Pragmas">Function Specific Option Pragmas</a>, 54Previous: <a rel="previous" accesskey="p" href="Visibility-Pragmas.html#Visibility-Pragmas">Visibility Pragmas</a>, 55Up: <a rel="up" accesskey="u" href="Pragmas.html#Pragmas">Pragmas</a> 56<hr> 57</div> 58 59<h4 class="subsection">6.56.12 Push/Pop Macro Pragmas</h4> 60 61<p>For compatibility with Microsoft Windows compilers, GCC supports 62‘<samp><span class="samp">#pragma push_macro(</span><var>"macro_name"</var><span class="samp">)</span></samp>’ 63and ‘<samp><span class="samp">#pragma pop_macro(</span><var>"macro_name"</var><span class="samp">)</span></samp>’. 64 65 <dl> 66<dt><code>#pragma push_macro(</code><var>"macro_name"</var><code>)</code><dd><a name="index-pragma_002c-push_005fmacro-3238"></a>This pragma saves the value of the macro named as <var>macro_name</var> to 67the top of the stack for this macro. 68 69 <br><dt><code>#pragma pop_macro(</code><var>"macro_name"</var><code>)</code><dd><a name="index-pragma_002c-pop_005fmacro-3239"></a>This pragma sets the value of the macro named as <var>macro_name</var> to 70the value on top of the stack for this macro. If the stack for 71<var>macro_name</var> is empty, the value of the macro remains unchanged. 72</dl> 73 74 <p>For example: 75 76<pre class="smallexample"> #define X 1 77 #pragma push_macro("X") 78 #undef X 79 #define X -1 80 #pragma pop_macro("X") 81 int x [X]; 82</pre> 83 <p>In this example, the definition of X as 1 is saved by <code>#pragma 84push_macro</code> and restored by <code>#pragma pop_macro</code>. 85 86 </body></html> 87 88