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109 lines
4.5 KiB
HTML
109 lines
4.5 KiB
HTML
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any later version published by the Free Software Foundation. A copy of
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(a) The FSF's Front-Cover Text is:
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<head>
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<title>Traditional miscellany (The C Preprocessor)</title>
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<link href="index.html#Top" rel="start" title="Top">
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<link href="Index-of-Directives.html#Index-of-Directives" rel="index" title="Index of Directives">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="Traditional-Mode.html#Traditional-Mode" rel="up" title="Traditional Mode">
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<link href="Traditional-warnings.html#Traditional-warnings" rel="next" title="Traditional warnings">
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<a name="Traditional-miscellany"></a>
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<div class="header">
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<p>
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Next: <a href="Traditional-warnings.html#Traditional-warnings" accesskey="n" rel="next">Traditional warnings</a>, Previous: <a href="Traditional-macros.html#Traditional-macros" accesskey="p" rel="prev">Traditional macros</a>, Up: <a href="Traditional-Mode.html#Traditional-Mode" accesskey="u" rel="up">Traditional Mode</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Index-of-Directives.html#Index-of-Directives" title="Index" rel="index">Index</a>]</p>
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</div>
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<hr>
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<a name="Traditional-miscellany-1"></a>
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<h3 class="section">10.3 Traditional miscellany</h3>
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<p>Here are some things to be aware of when using the traditional
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preprocessor.
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</p>
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<ul>
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<li> Preprocessing directives are recognized only when their leading
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‘<samp>#</samp>’ appears in the first column. There can be no whitespace
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between the beginning of the line and the ‘<samp>#</samp>’, but whitespace can
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follow the ‘<samp>#</samp>’.
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</li><li> A true traditional C preprocessor does not recognize ‘<samp>#error</samp>’ or
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‘<samp>#pragma</samp>’, and may not recognize ‘<samp>#elif</samp>’. CPP supports all
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the directives in traditional mode that it supports in ISO mode,
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including extensions, with the exception that the effects of
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‘<samp>#pragma GCC poison</samp>’ are undefined.
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</li><li> __STDC__ is not defined.
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</li><li> If you use digraphs the behavior is undefined.
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</li><li> If a line that looks like a directive appears within macro arguments,
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the behavior is undefined.
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</li></ul>
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</body>
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</html>
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