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diff --git a/share/doc/gccint/Collect2.html b/share/doc/gccint/Collect2.html new file mode 100644 index 0000000..5b9aa40 --- /dev/null +++ b/share/doc/gccint/Collect2.html @@ -0,0 +1,161 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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; with the +Invariant Sections being "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(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>GNU Compiler Collection (GCC) Internals: Collect2</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Collect2"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Collect2"> +<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="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="index.html#Top" rel="up" title="Top"> +<link href="Header-Dirs.html#Header-Dirs" rel="next" title="Header Dirs"> +<link href="Host-Fragment.html#Host-Fragment" rel="previous" title="Host Fragment"> +<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="Collect2"></a> +<div class="header"> +<p> +Next: <a href="Header-Dirs.html#Header-Dirs" accesskey="n" rel="next">Header Dirs</a>, Previous: <a href="Fragments.html#Fragments" accesskey="p" rel="previous">Fragments</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="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="collect2"></a> +<h2 class="chapter">21 <code>collect2</code></h2> + +<p>GCC uses a utility called <code>collect2</code> on nearly all systems to arrange +to call various initialization functions at start time. +</p> +<p>The program <code>collect2</code> works by linking the program once and +looking through the linker output file for symbols with particular names +indicating they are constructor functions. If it finds any, it +creates a new temporary ‘<samp>.c</samp>’ file containing a table of them, +compiles it, and links the program a second time including that file. +</p> +<a name="index-_005f_005fmain"></a> +<a name="index-constructors_002c-automatic-calls"></a> +<p>The actual calls to the constructors are carried out by a subroutine +called <code>__main</code>, which is called (automatically) at the beginning +of the body of <code>main</code> (provided <code>main</code> was compiled with GNU +CC). Calling <code>__main</code> is necessary, even when compiling C code, to +allow linking C and C++ object code together. (If you use +<samp>-nostdlib</samp>, you get an unresolved reference to <code>__main</code>, +since it’s defined in the standard GCC library. Include <samp>-lgcc</samp> at +the end of your compiler command line to resolve this reference.) +</p> +<p>The program <code>collect2</code> is installed as <code>ld</code> in the directory +where the passes of the compiler are installed. When <code>collect2</code> +needs to find the <em>real</em> <code>ld</code>, it tries the following file +names: +</p> +<ul> +<li> a hard coded linker file name, if GCC was configured with the +<samp>--with-ld</samp> option. + +</li><li> <samp>real-ld</samp> in the directories listed in the compiler’s search +directories. + +</li><li> <samp>real-ld</samp> in the directories listed in the environment variable +<code>PATH</code>. + +</li><li> The file specified in the <code>REAL_LD_FILE_NAME</code> configuration macro, +if specified. + +</li><li> <samp>ld</samp> in the compiler’s search directories, except that +<code>collect2</code> will not execute itself recursively. + +</li><li> <samp>ld</samp> in <code>PATH</code>. +</li></ul> + +<p>“The compiler’s search directories” means all the directories where +<code>gcc</code> searches for passes of the compiler. This includes +directories that you specify with <samp>-B</samp>. +</p> +<p>Cross-compilers search a little differently: +</p> +<ul> +<li> <samp>real-ld</samp> in the compiler’s search directories. + +</li><li> <samp><var>target</var>-real-ld</samp> in <code>PATH</code>. + +</li><li> The file specified in the <code>REAL_LD_FILE_NAME</code> configuration macro, +if specified. + +</li><li> <samp>ld</samp> in the compiler’s search directories. + +</li><li> <samp><var>target</var>-ld</samp> in <code>PATH</code>. +</li></ul> + +<p><code>collect2</code> explicitly avoids running <code>ld</code> using the file name +under which <code>collect2</code> itself was invoked. In fact, it remembers +up a list of such names—in case one copy of <code>collect2</code> finds +another copy (or version) of <code>collect2</code> installed as <code>ld</code> in a +second place in the search path. +</p> +<p><code>collect2</code> searches for the utilities <code>nm</code> and <code>strip</code> +using the same algorithm as above for <code>ld</code>. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Header-Dirs.html#Header-Dirs" accesskey="n" rel="next">Header Dirs</a>, Previous: <a href="Fragments.html#Fragments" accesskey="p" rel="previous">Fragments</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="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |