|
- <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- <html>
- <!-- Copyright (C) 1992-2020 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 6.5, http://www.gnu.org/software/texinfo/ -->
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
- <title>Include Files (STABS)</title>
-
- <meta name="description" content="Include Files (STABS)">
- <meta name="keywords" content="Include Files (STABS)">
- <meta name="resource-type" content="document">
- <meta name="distribution" content="global">
- <meta name="Generator" content="makeinfo">
- <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.indentedblock {margin-right: 0em}
- blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
- blockquote.smallquotation {font-size: smaller}
- div.display {margin-left: 3.2em}
- div.example {margin-left: 3.2em}
- div.lisp {margin-left: 3.2em}
- div.smalldisplay {margin-left: 3.2em}
- div.smallexample {margin-left: 3.2em}
- 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.nolinebreak {white-space: nowrap}
- span.roman {font-family: initial; font-weight: normal}
- span.sansserif {font-family: sans-serif; font-weight: normal}
- ul.no-bullet {list-style: none}
- -->
- </style>
-
-
- </head>
-
- <body lang="en">
- <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>
|