| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991-2013 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 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>Using as: Stab</title> |
| |
| <meta name="description" content="Using as: Stab"> |
| <meta name="keywords" content="Using as: Stab"> |
| <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="AS-Index.html#AS-Index" rel="index" title="AS Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="Pseudo-Ops.html#Pseudo-Ops" rel="up" title="Pseudo Ops"> |
| <link href="String.html#String" rel="next" title="String"> |
| <link href="Space.html#Space" rel="prev" title="Space"> |
| <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="Stab"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="String.html#String" accesskey="n" rel="next">String</a>, Previous: <a href="Space.html#Space" accesskey="p" rel="prev">Space</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="g_t_002estabd_002c-_002estabn_002c-_002estabs"></a> |
| <h3 class="section">7.107 <code>.stabd, .stabn, .stabs</code></h3> |
| |
| <a name="index-symbolic-debuggers_002c-information-for"></a> |
| <a name="index-stabx-directives"></a> |
| <p>There are three directives that begin ‘<samp>.stab</samp>’. |
| All emit symbols (see <a href="Symbols.html#Symbols">Symbols</a>), for use by symbolic debuggers. |
| The symbols are not entered in the <code>as</code> hash table: they |
| cannot be referenced elsewhere in the source file. |
| Up to five fields are required: |
| </p> |
| <dl compact="compact"> |
| <dt><var>string</var></dt> |
| <dd><p>This is the symbol’s name. It may contain any character except |
| ‘<samp>\000</samp>’, so is more general than ordinary symbol names. Some |
| debuggers used to code arbitrarily complex structures into symbol names |
| using this field. |
| </p> |
| </dd> |
| <dt><var>type</var></dt> |
| <dd><p>An absolute expression. The symbol’s type is set to the low 8 bits of |
| this expression. Any bit pattern is permitted, but <code>ld</code> |
| and debuggers choke on silly bit patterns. |
| </p> |
| </dd> |
| <dt><var>other</var></dt> |
| <dd><p>An absolute expression. The symbol’s “other” attribute is set to the |
| low 8 bits of this expression. |
| </p> |
| </dd> |
| <dt><var>desc</var></dt> |
| <dd><p>An absolute expression. The symbol’s descriptor is set to the low 16 |
| bits of this expression. |
| </p> |
| </dd> |
| <dt><var>value</var></dt> |
| <dd><p>An absolute expression which becomes the symbol’s value. |
| </p></dd> |
| </dl> |
| |
| <p>If a warning is detected while reading a <code>.stabd</code>, <code>.stabn</code>, |
| or <code>.stabs</code> statement, the symbol has probably already been created; |
| you get a half-formed symbol in your object file. This is |
| compatible with earlier assemblers! |
| </p> |
| <dl compact="compact"> |
| <dd><a name="index-stabd-directive"></a> |
| </dd> |
| <dt><code>.stabd <var>type</var> , <var>other</var> , <var>desc</var></code></dt> |
| <dd> |
| <p>The “name” of the symbol generated is not even an empty string. |
| It is a null pointer, for compatibility. Older assemblers used a |
| null pointer so they didn’t waste space in object files with empty |
| strings. |
| </p> |
| <p>The symbol’s value is set to the location counter, |
| relocatably. When your program is linked, the value of this symbol |
| is the address of the location counter when the <code>.stabd</code> was |
| assembled. |
| </p> |
| <a name="index-stabn-directive"></a> |
| </dd> |
| <dt><code>.stabn <var>type</var> , <var>other</var> , <var>desc</var> , <var>value</var></code></dt> |
| <dd><p>The name of the symbol is set to the empty string <code>""</code>. |
| </p> |
| <a name="index-stabs-directive"></a> |
| </dd> |
| <dt><code>.stabs <var>string</var> , <var>type</var> , <var>other</var> , <var>desc</var> , <var>value</var></code></dt> |
| <dd><p>All five fields are specified. |
| </p></dd> |
| </dl> |
| |
| <hr> |
| <div class="header"> |
| <p> |
| Next: <a href="String.html#String" accesskey="n" rel="next">String</a>, Previous: <a href="Space.html#Space" accesskey="p" rel="prev">Space</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| |
| |
| |
| </body> |
| </html> |
