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diff --git a/share/doc/gcc/Exceptions.html b/share/doc/gcc/Exceptions.html new file mode 100644 index 0000000..62efc4a --- /dev/null +++ b/share/doc/gcc/Exceptions.html @@ -0,0 +1,163 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- This file documents the use of the GNU compilers. + +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 "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + +A GNU Manual + +(b) The FSF's Back-Cover Text is: + +You have freedom to copy and modify this GNU Manual, like GNU + software. Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Using the GNU Compiler Collection (GCC): Exceptions</title> + +<meta name="description" content="Using the GNU Compiler Collection (GCC): Exceptions"> +<meta name="keywords" content="Using the GNU Compiler Collection (GCC): Exceptions"> +<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="Indices.html#Indices" rel="index" title="Indices"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Objective_002dC.html#Objective_002dC" rel="up" title="Objective-C"> +<link href="Synchronization.html#Synchronization" rel="next" title="Synchronization"> +<link href="compatibility_005falias.html#compatibility_005falias" rel="previous" title="compatibility_alias"> +<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_US" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Exceptions"></a> +<div class="header"> +<p> +Next: <a href="Synchronization.html#Synchronization" accesskey="n" rel="next">Synchronization</a>, Previous: <a href="compatibility_005falias.html#compatibility_005falias" accesskey="p" rel="previous">compatibility_alias</a>, Up: <a href="Objective_002dC.html#Objective_002dC" accesskey="u" rel="up">Objective-C</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Exceptions-1"></a> +<h3 class="section">8.7 Exceptions</h3> + +<p>GNU Objective-C provides exception support built into the language, as +in the following example: +</p> +<div class="smallexample"> +<pre class="smallexample"> @try { + … + @throw expr; + … + } + @catch (AnObjCClass *exc) { + … + @throw expr; + … + @throw; + … + } + @catch (AnotherClass *exc) { + … + } + @catch (id allOthers) { + … + } + @finally { + … + @throw expr; + … + } +</pre></div> + +<p>The <code>@throw</code> statement may appear anywhere in an Objective-C or +Objective-C++ program; when used inside of a <code>@catch</code> block, the +<code>@throw</code> may appear without an argument (as shown above), in +which case the object caught by the <code>@catch</code> will be rethrown. +</p> +<p>Note that only (pointers to) Objective-C objects may be thrown and +caught using this scheme. When an object is thrown, it will be caught +by the nearest <code>@catch</code> clause capable of handling objects of +that type, analogously to how <code>catch</code> blocks work in C++ and +Java. A <code>@catch(id …)</code> clause (as shown above) may also +be provided to catch any and all Objective-C exceptions not caught by +previous <code>@catch</code> clauses (if any). +</p> +<p>The <code>@finally</code> clause, if present, will be executed upon exit +from the immediately preceding <code>@try … @catch</code> section. +This will happen regardless of whether any exceptions are thrown, +caught or rethrown inside the <code>@try … @catch</code> section, +analogously to the behavior of the <code>finally</code> clause in Java. +</p> +<p>There are several caveats to using the new exception mechanism: +</p> +<ul> +<li> The <samp>-fobjc-exceptions</samp> command line option must be used when +compiling Objective-C files that use exceptions. + +</li><li> With the GNU runtime, exceptions are always implemented as “native” +exceptions and it is recommended that the <samp>-fexceptions</samp> and +<samp>-shared-libgcc</samp> options are used when linking. + +</li><li> With the NeXT runtime, although currently designed to be binary +compatible with <code>NS_HANDLER</code>-style idioms provided by the +<code>NSException</code> class, the new exceptions can only be used on Mac +OS X 10.3 (Panther) and later systems, due to additional functionality +needed in the NeXT Objective-C runtime. + +</li><li> As mentioned above, the new exceptions do not support handling +types other than Objective-C objects. Furthermore, when used from +Objective-C++, the Objective-C exception model does not interoperate with C++ +exceptions at this time. This means you cannot <code>@throw</code> an exception +from Objective-C and <code>catch</code> it in C++, or vice versa +(i.e., <code>throw … @catch</code>). +</li></ul> + +<hr> +<div class="header"> +<p> +Next: <a href="Synchronization.html#Synchronization" accesskey="n" rel="next">Synchronization</a>, Previous: <a href="compatibility_005falias.html#compatibility_005falias" accesskey="p" rel="previous">compatibility_alias</a>, Up: <a href="Objective_002dC.html#Objective_002dC" accesskey="u" rel="up">Objective-C</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |