diff options
Diffstat (limited to 'share/doc/stabs/Include-Files.html')
| -rw-r--r-- | share/doc/stabs/Include-Files.html | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/share/doc/stabs/Include-Files.html b/share/doc/stabs/Include-Files.html new file mode 100644 index 0000000..c934cb5 --- /dev/null +++ b/share/doc/stabs/Include-Files.html @@ -0,0 +1,132 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1992-2023 Free Software Foundation, Inc. +Contributed by Cygnus Support. Written by Julia Menapace, Jim Kingdon, +and David MacKenzie. + +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 no +Invariant Sections, with no Front-Cover Texts, and with no Back-Cover +Texts. A copy of the license is included in the section entitled "GNU +Free Documentation License". --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>STABS: Include Files</title> + +<meta name="description" content="STABS: Include Files"> +<meta name="keywords" content="STABS: Include Files"> +<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="Symbol-Types-Index.html#Symbol-Types-Index" rel="index" title="Symbol Types Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Program-Structure.html#Program-Structure" rel="up" title="Program Structure"> +<link href="Line-Numbers.html#Line-Numbers" rel="next" title="Line Numbers"> +<link href="Source-Files.html#Source-Files" rel="previous" title="Source Files"> +<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="Include-Files"></a> +<div class="header"> +<p> +Next: <a href="Line-Numbers.html#Line-Numbers" accesskey="n" rel="next">Line Numbers</a>, Previous: <a href="Source-Files.html#Source-Files" accesskey="p" rel="previous">Source Files</a>, Up: <a href="Program-Structure.html#Program-Structure" accesskey="u" rel="up">Program Structure</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Names-of-Include-Files"></a> +<h3 class="section">2.3 Names of Include Files</h3> + +<p>There are several schemes for dealing with include files: the +traditional <code>N_SOL</code> approach, Sun’s <code>N_BINCL</code> approach, and the +XCOFF <code>C_BINCL</code> approach (which despite the similar name has little in +common with <code>N_BINCL</code>). +</p> +<a name="index-N_005fSOL"></a> +<p>An <code>N_SOL</code> symbol specifies which include file subsequent symbols +refer to. The string field is the name of the file and the value is the +text address corresponding to the end of the previous include file and +the start of this one. To specify the main source file again, use an +<code>N_SOL</code> symbol with the name of the main source file. +</p> +<a name="index-N_005fBINCL"></a> +<a name="index-N_005fEINCL"></a> +<a name="index-N_005fEXCL"></a> +<p>The <code>N_BINCL</code> approach works as follows. An <code>N_BINCL</code> symbol +specifies the start of an include file. In an object file, only the +string is significant; the linker puts data into some of the other +fields. The end of the include file is marked by an <code>N_EINCL</code> +symbol (which has no string field). In an object file, there is no +significant data in the <code>N_EINCL</code> symbol. <code>N_BINCL</code> and +<code>N_EINCL</code> can be nested. +</p> +<p>If the linker detects that two source files have identical stabs between +an <code>N_BINCL</code> and <code>N_EINCL</code> pair (as will generally be the case +for a header file), then it only puts out the stabs once. Each +additional occurrence is replaced by an <code>N_EXCL</code> symbol. I believe +the GNU linker and the Sun (both SunOS4 and Solaris) linker are the only +ones which supports this feature. +</p> +<p>A linker which supports this feature will set the value of a +<code>N_BINCL</code> symbol to the total of all the characters in the stabs +strings included in the header file, omitting any file numbers. The +value of an <code>N_EXCL</code> symbol is the same as the value of the +<code>N_BINCL</code> symbol it replaces. This information can be used to +match up <code>N_EXCL</code> and <code>N_BINCL</code> symbols which have the same +filename. The <code>N_EINCL</code> value, and the values of the other and +description fields for all three, appear to always be zero. +</p> +<a name="index-C_005fBINCL"></a> +<a name="index-C_005fEINCL"></a> +<p>For the start of an include file in XCOFF, use the <samp>.bi</samp> assembler +directive, which generates a <code>C_BINCL</code> symbol. A <samp>.ei</samp> +directive, which generates a <code>C_EINCL</code> symbol, denotes the end of +the include file. Both directives are followed by the name of the +source file in quotes, which becomes the string for the symbol. +The value of each symbol, produced automatically by the assembler +and linker, is the offset into the executable of the beginning +(inclusive, as you’d expect) or end (inclusive, as you would not expect) +of the portion of the COFF line table that corresponds to this include +file. <code>C_BINCL</code> and <code>C_EINCL</code> do not nest. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Line-Numbers.html#Line-Numbers" accesskey="n" rel="next">Line Numbers</a>, Previous: <a href="Source-Files.html#Source-Files" accesskey="p" rel="previous">Source Files</a>, Up: <a href="Program-Structure.html#Program-Structure" accesskey="u" rel="up">Program Structure</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |