devdocs/gcc~13/push_002fpop-macro-pragmas.html


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<div class="subsection-level-extent" id="Push_002fPop-Macro-Pragmas"> <div class="nav-panel"> <p> Next: <a href="function-specific-option-pragmas" accesskey="n" rel="next">Function Specific Option Pragmas</a>, Previous: <a href="visibility-pragmas" accesskey="p" rel="prev">Visibility Pragmas</a>, Up: <a href="pragmas" accesskey="u" rel="up">Pragmas Accepted by GCC</a> [<a href="index#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="indices" title="Index" rel="index">Index</a>]</p> </div>  <h1 class="subsection" id="Push_002fPop-Macro-Pragmas-1"><span>6.62.14 Push/Pop Macro Pragmas<a class="copiable-link" href="#Push_002fPop-Macro-Pragmas-1"> ¶</a></span></h1> <p>For compatibility with Microsoft Windows compilers, GCC supports ‘<samp class="samp">#pragma push_macro(<var class="var">"macro_name"</var>)</samp>’ and ‘<samp class="samp">#pragma pop_macro(<var class="var">"macro_name"</var>)</samp>’. </p> <dl class="table"> <dt>
<span><code class="code">#pragma push_macro(<var class="var">"macro_name"</var>)</code><a class="copiable-link" href="#index-pragma_002c-push_005fmacro"> ¶</a></span>
</dt> <dd>
<p>This pragma saves the value of the macro named as <var class="var">macro_name</var> to the top of the stack for this macro. </p> </dd> <dt>
<span><code class="code">#pragma pop_macro(<var class="var">"macro_name"</var>)</code><a class="copiable-link" href="#index-pragma_002c-pop_005fmacro"> ¶</a></span>
</dt> <dd><p>This pragma sets the value of the macro named as <var class="var">macro_name</var> to the value on top of the stack for this macro. If the stack for <var class="var">macro_name</var> is empty, the value of the macro remains unchanged. </p></dd> </dl> <p>For example: </p> <div class="example smallexample"> <pre class="example-preformatted" data-language="cpp">#define X  1
#pragma push_macro("X")
#undef X
#define X -1
#pragma pop_macro("X")
int x [X];</pre>
</div> <p>In this example, the definition of X as 1 is saved by <code class="code">#pragma
push_macro</code> and restored by <code class="code">#pragma pop_macro</code>. </p> </div><div class="_attribution">
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