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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/cpp/Line-Control.html | |
https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads
Change-Id: I7303388733328cd98ab9aa3c30236db67f2e9e9c
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diff --git a/share/doc/cpp/Line-Control.html b/share/doc/cpp/Line-Control.html new file mode 100644 index 0000000..12e1aa1 --- /dev/null +++ b/share/doc/cpp/Line-Control.html @@ -0,0 +1,139 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1987-2023 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. A copy of +the license is included in the +section entitled "GNU Free Documentation License". + +This manual contains no Invariant Sections. The Front-Cover Texts are +(a) (see below), and the Back-Cover Texts are (b) (see below). + +(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 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>The C Preprocessor: Line Control</title> + +<meta name="description" content="The C Preprocessor: Line Control"> +<meta name="keywords" content="The C Preprocessor: Line Control"> +<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="Index-of-Directives.html#Index-of-Directives" rel="index" title="Index of Directives"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="index.html#Top" rel="up" title="Top"> +<link href="Pragmas.html#Pragmas" rel="next" title="Pragmas"> +<link href="Diagnostics.html#Diagnostics" rel="previous" title="Diagnostics"> +<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="Line-Control"></a> +<div class="header"> +<p> +Next: <a href="Pragmas.html#Pragmas" accesskey="n" rel="next">Pragmas</a>, Previous: <a href="Diagnostics.html#Diagnostics" accesskey="p" rel="previous">Diagnostics</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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> +</div> +<hr> +<a name="Line-Control-1"></a> +<h2 class="chapter">6 Line Control</h2> +<a name="index-line-control"></a> + +<p>The C preprocessor informs the C compiler of the location in your source +code where each token came from. Presently, this is just the file name +and line number. All the tokens resulting from macro expansion are +reported as having appeared on the line of the source file where the +outermost macro was used. We intend to be more accurate in the future. +</p> +<p>If you write a program which generates source code, such as the +<code>bison</code> parser generator, you may want to adjust the preprocessor’s +notion of the current file name and line number by hand. Parts of the +output from <code>bison</code> are generated from scratch, other parts come +from a standard parser file. The rest are copied verbatim from +<code>bison</code>’s input. You would like compiler error messages and +symbolic debuggers to be able to refer to <code>bison</code>’s input file. +</p> +<a name="index-_0023line"></a> +<p><code>bison</code> or any such program can arrange this by writing +‘<samp>#line</samp>’ directives into the output file. ‘<samp>#line</samp>’ is a +directive that specifies the original line number and source file name +for subsequent input in the current preprocessor input file. +‘<samp>#line</samp>’ has three variants: +</p> +<dl compact="compact"> +<dt><code>#line <var>linenum</var></code></dt> +<dd><p><var>linenum</var> is a non-negative decimal integer constant. It specifies +the line number which should be reported for the following line of +input. Subsequent lines are counted from <var>linenum</var>. +</p> +</dd> +<dt><code>#line <var>linenum</var> <var>filename</var></code></dt> +<dd><p><var>linenum</var> is the same as for the first form, and has the same +effect. In addition, <var>filename</var> is a string constant. The +following line and all subsequent lines are reported to come from the +file it specifies, until something else happens to change that. +<var>filename</var> is interpreted according to the normal rules for a string +constant: backslash escapes are interpreted. This is different from +‘<samp>#include</samp>’. +</p> +</dd> +<dt><code>#line <var>anything else</var></code></dt> +<dd><p><var>anything else</var> is checked for macro calls, which are expanded. +The result should match one of the above two forms. +</p></dd> +</dl> + +<p>‘<samp>#line</samp>’ directives alter the results of the <code>__FILE__</code> and +<code>__LINE__</code> predefined macros from that point on. See <a href="Standard-Predefined-Macros.html#Standard-Predefined-Macros">Standard Predefined Macros</a>. They do not have any effect on ‘<samp>#include</samp>’’s +idea of the directory containing the current file. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Pragmas.html#Pragmas" accesskey="n" rel="next">Pragmas</a>, Previous: <a href="Diagnostics.html#Diagnostics" accesskey="p" rel="previous">Diagnostics</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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> +</div> + + + +</body> +</html> |