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85 lines
3.8 KiB
HTML
85 lines
3.8 KiB
HTML
4 years ago
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<title>Push/Pop Macro Pragmas - Using the GNU Compiler Collection (GCC)</title>
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<meta name="description" content="Using the GNU Compiler Collection (GCC)">
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<link title="Top" rel="start" href="index.html#Top">
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<link rel="up" href="Pragmas.html#Pragmas" title="Pragmas">
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<link rel="prev" href="Visibility-Pragmas.html#Visibility-Pragmas" title="Visibility Pragmas">
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<link rel="next" href="Function-Specific-Option-Pragmas.html#Function-Specific-Option-Pragmas" title="Function Specific Option Pragmas">
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Copyright (C) 1988-2015 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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(a) The FSF's Front-Cover Text is:
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A GNU Manual
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</head>
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<body>
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<div class="node">
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<a name="Push%2fPop-Macro-Pragmas"></a>
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<a name="Push_002fPop-Macro-Pragmas"></a>
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<p>
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Next: <a rel="next" accesskey="n" href="Function-Specific-Option-Pragmas.html#Function-Specific-Option-Pragmas">Function Specific Option Pragmas</a>,
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Previous: <a rel="previous" accesskey="p" href="Visibility-Pragmas.html#Visibility-Pragmas">Visibility Pragmas</a>,
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Up: <a rel="up" accesskey="u" href="Pragmas.html#Pragmas">Pragmas</a>
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<hr>
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</div>
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<h4 class="subsection">6.60.12 Push/Pop Macro Pragmas</h4>
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<p>For compatibility with Microsoft Windows compilers, GCC supports
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‘<samp><span class="samp">#pragma push_macro(</span><var>"macro_name"</var><span class="samp">)</span></samp>’
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and ‘<samp><span class="samp">#pragma pop_macro(</span><var>"macro_name"</var><span class="samp">)</span></samp>’.
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<dl>
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<dt><code>#pragma push_macro(</code><var>"macro_name"</var><code>)</code><dd><a name="index-pragma_002c-push_005fmacro-4181"></a>This pragma saves the value of the macro named as <var>macro_name</var> to
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the top of the stack for this macro.
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<br><dt><code>#pragma pop_macro(</code><var>"macro_name"</var><code>)</code><dd><a name="index-pragma_002c-pop_005fmacro-4182"></a>This pragma sets the value of the macro named as <var>macro_name</var> to
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the value on top of the stack for this macro. If the stack for
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<var>macro_name</var> is empty, the value of the macro remains unchanged.
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</dl>
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<p>For example:
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<pre class="smallexample"> #define X 1
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#pragma push_macro("X")
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#undef X
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#define X -1
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#pragma pop_macro("X")
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int x [X];
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</pre>
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<p class="noindent">In this example, the definition of X as 1 is saved by <code>#pragma
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push_macro</code> and restored by <code>#pragma pop_macro</code>.
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</body></html>
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