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diff --git a/share/doc/gdb/C-Plus-Plus-Expressions.html b/share/doc/gdb/C-Plus-Plus-Expressions.html new file mode 100644 index 0000000..6912a24 --- /dev/null +++ b/share/doc/gdb/C-Plus-Plus-Expressions.html @@ -0,0 +1,167 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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 the +Invariant Sections being "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: C Plus Plus Expressions</title> + +<meta name="description" content="Debugging with GDB: C Plus Plus Expressions"> +<meta name="keywords" content="Debugging with GDB: C Plus Plus Expressions"> +<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="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="C.html#C" rel="up" title="C"> +<link href="C-Defaults.html#C-Defaults" rel="next" title="C Defaults"> +<link href="C-Constants.html#C-Constants" rel="previous" title="C Constants"> +<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="C-Plus-Plus-Expressions"></a> +<div class="header"> +<p> +Next: <a href="C-Defaults.html#C-Defaults" accesskey="n" rel="next">C Defaults</a>, Previous: <a href="C-Constants.html#C-Constants" accesskey="p" rel="previous">C Constants</a>, Up: <a href="C.html#C" accesskey="u" rel="up">C</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="C_002b_002b-Expressions"></a> +<h4 class="subsubsection">15.4.1.3 C<tt>++</tt> Expressions</h4> + +<a name="index-expressions-in-C_002b_002b"></a> +<p><small>GDB</small> expression handling can interpret most C<tt>++</tt> expressions. +</p> +<a name="index-debugging-C_002b_002b-programs"></a> +<a name="index-C_002b_002b-compilers"></a> +<a name="index-debug-formats-and-C_002b_002b"></a> +<a name="index-GCC-and-C_002b_002b"></a> +<blockquote> +<p><em>Warning:</em> <small>GDB</small> can only debug C<tt>++</tt> code if you use +the proper compiler and the proper debug format. Currently, +<small>GDB</small> works best when debugging C<tt>++</tt> code that is compiled +with the most recent version of <small>GCC</small> possible. The DWARF +debugging format is preferred; <small>GCC</small> defaults to this on most +popular platforms. Other compilers and/or debug formats are likely to +work badly or not at all when using <small>GDB</small> to debug C<tt>++</tt> +code. See <a href="Compilation.html#Compilation">Compilation</a>. +</p></blockquote> + +<ol> +<li> <a name="index-member-functions"></a> +Member function calls are allowed; you can use expressions like + +<div class="smallexample"> +<pre class="smallexample">count = aml->GetOriginal(x, y) +</pre></div> + +</li><li> <a name="index-this_002c-inside-C_002b_002b-member-functions"></a> +<a name="index-namespace-in-C_002b_002b"></a> +While a member function is active (in the selected stack frame), your +expressions have the same namespace available as the member function; +that is, <small>GDB</small> allows implicit references to the class instance +pointer <code>this</code> following the same rules as C<tt>++</tt>. <code>using</code> +declarations in the current scope are also respected by <small>GDB</small>. + +</li><li> <a name="index-call-overloaded-functions"></a> +<a name="index-overloaded-functions_002c-calling"></a> +<a name="index-type-conversions-in-C_002b_002b"></a> +You can call overloaded functions; <small>GDB</small> resolves the function +call to the right definition, with some restrictions. <small>GDB</small> does not +perform overload resolution involving user-defined type conversions, +calls to constructors, or instantiations of templates that do not exist +in the program. It also cannot handle ellipsis argument lists or +default arguments. + +<p>It does perform integral conversions and promotions, floating-point +promotions, arithmetic conversions, pointer conversions, conversions of +class objects to base classes, and standard conversions such as those of +functions or arrays to pointers; it requires an exact match on the +number of function arguments. +</p> +<p>Overload resolution is always performed, unless you have specified +<code>set overload-resolution off</code>. See <a href="Debugging-C-Plus-Plus.html#Debugging-C-Plus-Plus"><small>GDB</small> Features for C<tt>++</tt></a>. +</p> +<p>You must specify <code>set overload-resolution off</code> in order to use an +explicit function signature to call an overloaded function, as in +</p><div class="smallexample"> +<pre class="smallexample">p 'foo(char,int)'('x', 13) +</pre></div> + +<p>The <small>GDB</small> command-completion facility can simplify this; +see <a href="Completion.html#Completion">Command Completion</a>. +</p> +</li><li> <a name="index-reference-declarations"></a> +<small>GDB</small> understands variables declared as C<tt>++</tt> lvalue or rvalue +references; you can use them in expressions just as you do in C<tt>++</tt> +source—they are automatically dereferenced. + +<p>In the parameter list shown when <small>GDB</small> displays a frame, the values of +reference variables are not displayed (unlike other variables); this +avoids clutter, since references are often used for large structures. +The <em>address</em> of a reference variable is always shown, unless +you have specified ‘<samp>set print address off</samp>’. +</p> +</li><li> <small>GDB</small> supports the C<tt>++</tt> name resolution operator <code>::</code>—your +expressions can use it just as expressions in your program do. Since +one scope may be defined in another, you can use <code>::</code> repeatedly if +necessary, for example in an expression like +‘<samp><var>scope1</var>::<var>scope2</var>::<var>name</var></samp>’. <small>GDB</small> also allows +resolving name scope by reference to source files, in both C and C<tt>++</tt> +debugging (see <a href="Variables.html#Variables">Program Variables</a>). + +</li><li> <small>GDB</small> performs argument-dependent lookup, following the C<tt>++</tt> +specification. +</li></ol> + +<hr> +<div class="header"> +<p> +Next: <a href="C-Defaults.html#C-Defaults" accesskey="n" rel="next">C Defaults</a>, Previous: <a href="C-Constants.html#C-Constants" accesskey="p" rel="previous">C Constants</a>, Up: <a href="C.html#C" accesskey="u" rel="up">C</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |