You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
174 lines
8.4 KiB
HTML
174 lines
8.4 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1992-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>Simple Classes (STABS)</title>
|
|
|
|
<meta name="description" content="Simple Classes (STABS)">
|
|
<meta name="keywords" content="Simple Classes (STABS)">
|
|
<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="Cplusplus.html#Cplusplus" rel="up" title="Cplusplus">
|
|
<link href="Class-Instance.html#Class-Instance" rel="next" title="Class Instance">
|
|
<link href="Basic-Cplusplus-Types.html#Basic-Cplusplus-Types" rel="prev" title="Basic Cplusplus Types">
|
|
<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="Simple-Classes"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Class-Instance.html#Class-Instance" accesskey="n" rel="next">Class Instance</a>, Previous: <a href="Basic-Cplusplus-Types.html#Basic-Cplusplus-Types" accesskey="p" rel="prev">Basic Cplusplus Types</a>, Up: <a href="Cplusplus.html#Cplusplus" accesskey="u" rel="up">Cplusplus</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="Simple-Class-Definition"></a>
|
|
<h3 class="section">8.4 Simple Class Definition</h3>
|
|
|
|
<p>The stabs describing C<tt>++</tt> language features are an extension of the
|
|
stabs describing C. Stabs representing C<tt>++</tt> class types elaborate
|
|
extensively on the stab format used to describe structure types in C.
|
|
Stabs representing class type variables look just like stabs
|
|
representing C language variables.
|
|
</p>
|
|
<p>Consider the following very simple class definition.
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example">class baseA {
|
|
public:
|
|
int Adat;
|
|
int Ameth(int in, char other);
|
|
};
|
|
</pre></div>
|
|
|
|
<p>The class <code>baseA</code> is represented by two stabs. The first stab describes
|
|
the class as a structure type. The second stab describes a structure
|
|
tag of the class type. Both stabs are of stab type <code>N_LSYM</code>. Since the
|
|
stab is not located between an <code>N_FUN</code> and an <code>N_LBRAC</code> stab this indicates
|
|
that the class is defined at file scope. If it were, then the <code>N_LSYM</code>
|
|
would signify a local variable.
|
|
</p>
|
|
<p>A stab describing a C<tt>++</tt> class type is similar in format to a stab
|
|
describing a C struct, with each class member shown as a field in the
|
|
structure. The part of the struct format describing fields is
|
|
expanded to include extra information relevant to C<tt>++</tt> class members.
|
|
In addition, if the class has multiple base classes or virtual
|
|
functions the struct format outside of the field parts is also
|
|
augmented.
|
|
</p>
|
|
<p>In this simple example the field part of the C<tt>++</tt> class stab
|
|
representing member data looks just like the field part of a C struct
|
|
stab. The section on protections describes how its format is
|
|
sometimes extended for member data.
|
|
</p>
|
|
<p>The field part of a C<tt>++</tt> class stab representing a member function
|
|
differs substantially from the field part of a C struct stab. It
|
|
still begins with ‘<samp>name:</samp>’ but then goes on to define a new type number
|
|
for the member function, describe its return type, its argument types,
|
|
its protection level, any qualifiers applied to the method definition,
|
|
and whether the method is virtual or not. If the method is virtual
|
|
then the method description goes on to give the vtable index of the
|
|
method, and the type number of the first base class defining the
|
|
method.
|
|
</p>
|
|
<p>When the field name is a method name it is followed by two colons rather
|
|
than one. This is followed by a new type definition for the method.
|
|
This is a number followed by an equal sign and the type of the method.
|
|
Normally this will be a type declared using the ‘<samp>#</samp>’ type
|
|
descriptor; see <a href="Method-Type-Descriptor.html#Method-Type-Descriptor">Method Type Descriptor</a>; static member functions
|
|
are declared using the ‘<samp>f</samp>’ type descriptor instead; see
|
|
<a href="Function-Types.html#Function-Types">Function Types</a>.
|
|
</p>
|
|
<p>The format of an overloaded operator method name differs from that of
|
|
other methods. It is ‘<samp>op$::<var>operator-name</var>.</samp>’ where
|
|
<var>operator-name</var> is the operator name such as ‘<samp>+</samp>’ or ‘<samp>+=</samp>’.
|
|
The name ends with a period, and any characters except the period can
|
|
occur in the <var>operator-name</var> string.
|
|
</p>
|
|
<p>The next part of the method description represents the arguments to the
|
|
method, preceded by a colon and ending with a semi-colon. The types of
|
|
the arguments are expressed in the same way argument types are expressed
|
|
in C<tt>++</tt> name mangling. In this example an <code>int</code> and a <code>char</code>
|
|
map to ‘<samp>ic</samp>’.
|
|
</p>
|
|
<p>This is followed by a number, a letter, and an asterisk or period,
|
|
followed by another semicolon. The number indicates the protections
|
|
that apply to the member function. Here the 2 means public. The
|
|
letter encodes any qualifier applied to the method definition. In
|
|
this case, ‘<samp>A</samp>’ means that it is a normal function definition. The dot
|
|
shows that the method is not virtual. The sections that follow
|
|
elaborate further on these fields and describe the additional
|
|
information present for virtual methods.
|
|
</p>
|
|
|
|
<div class="display">
|
|
<pre class="display">.stabs "class_name:sym_desc(type)type_def(20)=type_desc(struct)struct_bytes(4)
|
|
field_name(Adat):type(int),bit_offset(0),field_bits(32);
|
|
|
|
method_name(Ameth)::type_def(21)=type_desc(method)return_type(int);
|
|
:arg_types(int char);
|
|
protection(public)qualifier(normal)virtual(no);;"
|
|
N_LSYM,NIL,NIL,NIL
|
|
</pre></div>
|
|
|
|
<div class="smallexample">
|
|
<pre class="smallexample">.stabs "baseA:t20=s4Adat:1,0,32;Ameth::21=##1;:ic;2A.;;",128,0,0,0
|
|
|
|
.stabs "class_name:sym_desc(struct tag)",N_LSYM,NIL,NIL,NIL
|
|
|
|
.stabs "baseA:T20",128,0,0,0
|
|
</pre></div>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Class-Instance.html#Class-Instance" accesskey="n" rel="next">Class Instance</a>, Previous: <a href="Basic-Cplusplus-Types.html#Basic-Cplusplus-Types" accesskey="p" rel="prev">Basic Cplusplus Types</a>, Up: <a href="Cplusplus.html#Cplusplus" accesskey="u" rel="up">Cplusplus</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>
|