133 lines
6.7 KiB
HTML
133 lines
6.7 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1992-2017 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 5.2, 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="prev" 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="prev">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="prev">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>
|