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diff --git a/share/doc/gccint/GIMPLE-Exception-Handling.html b/share/doc/gccint/GIMPLE-Exception-Handling.html new file mode 100644 index 0000000..d8fe1a3 --- /dev/null +++ b/share/doc/gccint/GIMPLE-Exception-Handling.html @@ -0,0 +1,129 @@ +<!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 "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>GNU Compiler Collection (GCC) Internals: GIMPLE Exception Handling</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: GIMPLE Exception Handling"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: GIMPLE Exception Handling"> +<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="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="GIMPLE.html#GIMPLE" rel="up" title="GIMPLE"> +<link href="Temporaries.html#Temporaries" rel="next" title="Temporaries"> +<link href="GIMPLE-instruction-set.html#GIMPLE-instruction-set" rel="previous" title="GIMPLE instruction set"> +<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="GIMPLE-Exception-Handling"></a> +<div class="header"> +<p> +Next: <a href="Temporaries.html#Temporaries" accesskey="n" rel="next">Temporaries</a>, Previous: <a href="GIMPLE-instruction-set.html#GIMPLE-instruction-set" accesskey="p" rel="previous">GIMPLE instruction set</a>, Up: <a href="GIMPLE.html#GIMPLE" accesskey="u" rel="up">GIMPLE</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Exception-Handling-1"></a> +<h3 class="section">12.4 Exception Handling</h3> +<a name="index-GIMPLE-Exception-Handling"></a> + +<p>Other exception handling constructs are represented using +<code>GIMPLE_TRY_CATCH</code>. <code>GIMPLE_TRY_CATCH</code> has two operands. The +first operand is a sequence of statements to execute. If executing +these statements does not throw an exception, then the second operand +is ignored. Otherwise, if an exception is thrown, then the second +operand of the <code>GIMPLE_TRY_CATCH</code> is checked. The second +operand may have the following forms: +</p> +<ol> +<li> A sequence of statements to execute. When an exception occurs, +these statements are executed, and then the exception is rethrown. + +</li><li> A sequence of <code>GIMPLE_CATCH</code> statements. Each +<code>GIMPLE_CATCH</code> has a list of applicable exception types and +handler code. If the thrown exception matches one of the caught +types, the associated handler code is executed. If the handler +code falls off the bottom, execution continues after the original +<code>GIMPLE_TRY_CATCH</code>. + +</li><li> A <code>GIMPLE_EH_FILTER</code> statement. This has a list of +permitted exception types, and code to handle a match failure. If the +thrown exception does not match one of the allowed types, the +associated match failure code is executed. If the thrown exception +does match, it continues unwinding the stack looking for the next +handler. + +</li></ol> + +<p>Currently throwing an exception is not directly represented in +GIMPLE, since it is implemented by calling a function. At some +point in the future we will want to add some way to express that +the call will throw an exception of a known type. +</p> +<p>Just before running the optimizers, the compiler lowers the +high-level EH constructs above into a set of ‘<samp>goto</samp>’s, magic +labels, and EH regions. Continuing to unwind at the end of a +cleanup is represented with a <code>GIMPLE_RESX</code>. +</p> + +<hr> +<div class="header"> +<p> +Next: <a href="Temporaries.html#Temporaries" accesskey="n" rel="next">Temporaries</a>, Previous: <a href="GIMPLE-instruction-set.html#GIMPLE-instruction-set" accesskey="p" rel="previous">GIMPLE instruction set</a>, Up: <a href="GIMPLE.html#GIMPLE" accesskey="u" rel="up">GIMPLE</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |