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diff --git a/share/doc/stabs/Structures.html b/share/doc/stabs/Structures.html new file mode 100644 index 0000000..efa3519 --- /dev/null +++ b/share/doc/stabs/Structures.html @@ -0,0 +1,139 @@ +<!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: Structures</title> + +<meta name="description" content="STABS: Structures"> +<meta name="keywords" content="STABS: Structures"> +<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="Types.html#Types" rel="up" title="Types"> +<link href="Typedefs.html#Typedefs" rel="next" title="Typedefs"> +<link href="Enumerations.html#Enumerations" rel="previous" title="Enumerations"> +<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="Structures"></a> +<div class="header"> +<p> +Next: <a href="Typedefs.html#Typedefs" accesskey="n" rel="next">Typedefs</a>, Previous: <a href="Enumerations.html#Enumerations" accesskey="p" rel="previous">Enumerations</a>, Up: <a href="Types.html#Types" accesskey="u" rel="up">Types</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="Structures-1"></a> +<h3 class="section">5.8 Structures</h3> + +<p>The encoding of structures in stabs can be shown with an example. +</p> +<p>The following source code declares a structure tag and defines an +instance of the structure in global scope. Then a <code>typedef</code> equates the +structure tag with a new type. Separate stabs are generated for the +structure tag, the structure <code>typedef</code>, and the structure instance. The +stabs for the tag and the <code>typedef</code> are emitted when the definitions are +encountered. Since the structure elements are not initialized, the +stab and code for the structure variable itself is located at the end +of the program in the bss section. +</p> +<div class="example"> +<pre class="example">struct s_tag { + int s_int; + float s_float; + char s_char_vec[8]; + struct s_tag* s_next; +} g_an_s; + +typedef struct s_tag s_typedef; +</pre></div> + +<p>The structure tag has an <code>N_LSYM</code> stab type because, like the +enumeration, the symbol has file scope. Like the enumeration, the +symbol descriptor is ‘<samp>T</samp>’, for enumeration, structure, or tag type. +The type descriptor ‘<samp>s</samp>’ following the ‘<samp>16=</samp>’ of the type +definition narrows the symbol type to structure. +</p> +<p>Following the ‘<samp>s</samp>’ type descriptor is the number of bytes the +structure occupies, followed by a description of each structure element. +The structure element descriptions are of the form +‘<samp><var>name</var>:<var>type</var>, <var>bit offset from the start of the +struct</var>, <var>number of bits in the element</var></samp>’. +</p> +<div class="example"> +<pre class="example"># <span class="roman">128 is N_LSYM</span> +.stabs "s_tag:T16=s20s_int:1,0,32;s_float:12,32,32; + s_char_vec:17=ar1;0;7;2,64,64;s_next:18=*16,128,32;;",128,0,0,0 +</pre></div> + +<p>In this example, the first two structure elements are previously defined +types. For these, the type following the ‘<samp><var>name</var>:</samp>’ part of the +element description is a simple type reference. The other two structure +elements are new types. In this case there is a type definition +embedded after the ‘<samp><var>name</var>:</samp>’. The type definition for the +array element looks just like a type definition for a stand-alone array. +The <code>s_next</code> field is a pointer to the same kind of structure that +the field is an element of. So the definition of structure type 16 +contains a type definition for an element which is a pointer to type 16. +</p> +<p>If a field is a static member (this is a C<tt>++</tt> feature in which a single +variable appears to be a field of every structure of a given type) it +still starts out with the field name, a colon, and the type, but then +instead of a comma, bit position, comma, and bit size, there is a colon +followed by the name of the variable which each such field refers to. +</p> +<p>If the structure has methods (a C<tt>++</tt> feature), they follow the non-method +fields; see <a href="Cplusplus.html#Cplusplus">Cplusplus</a>. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Typedefs.html#Typedefs" accesskey="n" rel="next">Typedefs</a>, Previous: <a href="Enumerations.html#Enumerations" accesskey="p" rel="previous">Enumerations</a>, Up: <a href="Types.html#Types" accesskey="u" rel="up">Types</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> |