| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1988-2015 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 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Using the GNU Compiler Collection (GCC): Java Exceptions</title> |
| |
| <meta name="description" content="Using the GNU Compiler Collection (GCC): Java Exceptions"> |
| <meta name="keywords" content="Using the GNU Compiler Collection (GCC): Java 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="Option-Index.html#Option-Index" rel="index" title="Option Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" rel="up" title="C++ Extensions"> |
| <link href="Deprecated-Features.html#Deprecated-Features" rel="next" title="Deprecated Features"> |
| <link href="Type-Traits.html#Type-Traits" rel="prev" title="Type Traits"> |
| <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="Java-Exceptions"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="Deprecated-Features.html#Deprecated-Features" accesskey="n" rel="next">Deprecated Features</a>, Previous: <a href="Type-Traits.html#Type-Traits" accesskey="p" rel="prev">Type Traits</a>, Up: <a href="C_002b_002b-Extensions.html#C_002b_002b-Extensions" accesskey="u" rel="up">C++ Extensions</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="Java-Exceptions-1"></a> |
| <h3 class="section">7.11 Java Exceptions</h3> |
| |
| <p>The Java language uses a slightly different exception handling model |
| from C++. Normally, GNU C++ automatically detects when you are |
| writing C++ code that uses Java exceptions, and handle them |
| appropriately. However, if C++ code only needs to execute destructors |
| when Java exceptions are thrown through it, GCC guesses incorrectly. |
| Sample problematic code is: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample"> struct S { ~S(); }; |
| extern void bar(); // <span class="roman">is written in Java, and may throw exceptions</span> |
| void foo() |
| { |
| S s; |
| bar(); |
| } |
| </pre></div> |
| |
| <p>The usual effect of an incorrect guess is a link failure, complaining of |
| a missing routine called ‘<samp>__gxx_personality_v0</samp>’. |
| </p> |
| <p>You can inform the compiler that Java exceptions are to be used in a |
| translation unit, irrespective of what it might think, by writing |
| ‘<samp>#pragma GCC <span class="nolinebreak">java_exceptions</span><!-- /@w --></samp>’ at the head of the file. This |
| ‘<samp>#pragma</samp>’ must appear before any functions that throw or catch |
| exceptions, or run destructors when exceptions are thrown through them. |
| </p> |
| <p>You cannot mix Java and C++ exceptions in the same translation unit. It |
| is believed to be safe to throw a C++ exception from one file through |
| another file compiled for the Java exception model, or vice versa, but |
| there may be bugs in this area. |
| </p> |
| |
| |
| |
| </body> |
| </html> |
