📄 autobook_152.html
字号:
<HTML><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><!-- Created on September, 12 2004 by texi2html 1.64 --><!-- Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author) Karl Berry <karl@freefriends.org> Olaf Bachmann <obachman@mathematik.uni-kl.de> and many others.Maintained by: Olaf Bachmann <obachman@mathematik.uni-kl.de>Send bugs and suggestions to <texi2html@mathematik.uni-kl.de> --><HEAD><TITLE>Autoconf, Automake, and Libtool: Name Mangling</TITLE><META NAME="description" CONTENT="Autoconf, Automake, and Libtool: Name Mangling"><META NAME="keywords" CONTENT="Autoconf, Automake, and Libtool: Name Mangling"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><META NAME="Generator" CONTENT="texi2html 1.64"><script language="Javascript"><!-- // Check the browser version. function checkVersion() { if (navigator.appVersion.charAt(0)>=3) return true; if (navigator.appVersion.charAt(0)>=4) return true; else return false; } if (checkVersion()) { homeon = new Image(); homeon.src = "homeon.png"; homeoff = new Image(); homeoff.src = "home.png"; tocon = new Image(); tocon.src = "tocon.png"; tocoff = new Image(); tocoff.src = "toc.png"; indexon = new Image(); indexon.src = "indexon.png"; indexoff = new Image(); indexoff.src = "index.png"; helpon = new Image(); helpon.src = "helpon.png"; helpoff = new Image(); helpoff.src = "help.png"; backon = new Image(); backon.src = "backon.png"; backoff = new Image(); backoff.src = "back.png"; forwardon = new Image(); forwardon.src = "forwardon.png"; forwardoff = new Image(); forwardoff.src = "forward.png"; prevon = new Image(); prevon.src = "prevon.png"; prevoff = new Image(); prevoff.src = "prev.png"; nexton = new Image(); nexton.src = "nexton.png"; nextoff = new Image(); nextoff.src = "next.png"; upon = new Image(); upon.src = "upon.png"; upoff = new Image(); upoff.src = "up.png"; } function img_act(imgName) { if (checkVersion()) { imgOn = eval(imgName + "on.src"); document [imgName].src = imgOn; } } function img_inact(imgName) { if (checkVersion()) { imgOff = eval(imgName + "off.src"); document [imgName].src = imgOff; } }// --></SCRIPT></HEAD><BODY LANG="EN" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#6688AA" VLINK="#336688" ALINK="#808080"><A NAME="SEC152"></A><TABLE BORDER=0 CELLPADDING=0 CELLSPACING=10><TR VALIGN="TOP"><TD ALIGN="MIDDLE" WIDTH=50 BGCOLOR="#e6e6e6"><TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_151.html#SEC151" onMouseover="img_act('prev')" onMouseout="img_inact('prev')"><IMG SRC="prev.png" BORDER="0" ALT="Back: Template Instantiation" ALIGN="MIDDLE" NAME="prev"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_153.html#SEC153" onMouseover="img_act('next')" onMouseout="img_inact('next')"><IMG SRC="next.png" BORDER="0" ALT="Forward: How GNU Autotools Can Help" ALIGN="MIDDLE" NAME="next"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"> <TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_153.html#SEC153" onMouseover="img_act('back')" onMouseout="img_inact('back')"><IMG SRC="back.png" BORDER="0" ALT="FastBack: How GNU Autotools Can Help" ALIGN="MIDDLE" NAME="back"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_150.html#SEC150" onMouseover="img_act('up')" onMouseout="img_inact('up')"><IMG SRC="up.png" BORDER="0" ALT="Up: Compiler Quirks" ALIGN="MIDDLE" NAME="up"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_153.html#SEC153" onMouseover="img_act('forward')" onMouseout="img_inact('forward')"><IMG SRC="forward.png" BORDER="0" ALT="FastForward: How GNU Autotools Can Help" ALIGN="MIDDLE" NAME="forward"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook.html#SEC_Top" onMouseover="img_act('home')" onMouseout="img_inact('home')"><IMG SRC="home.png" BORDER="0" ALT="Top: Autoconf, Automake, and Libtool" ALIGN="MIDDLE" NAME="home"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_toc.html#SEC_Contents" onMouseover="img_act('toc')" onMouseout="img_inact('toc')"><IMG SRC="toc.png" BORDER="0" ALT="Contents: Table of Contents" ALIGN="MIDDLE" NAME="toc"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_285.html#SEC285" onMouseover="img_act('index')" onMouseout="img_inact('index')"><IMG SRC="index.png" BORDER="0" ALT="Index: Index" ALIGN="MIDDLE" NAME="index"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_abt.html#SEC_About" onMouseover="img_act('help')" onMouseout="img_inact('help')"><IMG SRC="help.png" BORDER="0" ALT="About: About this document" ALIGN="MIDDLE" NAME="help"></A></TD></TR></TABLE></TD><TD ALIGN="LEFT"><H3> 16.3.2 Name Mangling </H3><!--docid::SEC152::--><P>Early C++ compilers mangled the names of C++ symbols so that existinglinkers could be used without modification. The cfront C++ translatoralso mangled names so that information from the original C++ programwould not be lost in the translation to C. Today, name mangling remainsimportant for enabling overloaded function names and link-time typechecking. Here is an example C++ source file which illustrates namemangling in action:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>class Foo{public: Foo (); void go (); void go (int where);private: int pos;};Foo::Foo (){ pos = 0;}voidFoo::go (){ go (0);}voidFoo::go (int where){ pos = where;}intmain (){ Foo f; f.go (10);}$ g++ -Wall example.cxx -o example.o$ nm --defined-only example.o00000000 T __3Foo00000000 ? __FRAME_BEGIN__00000000 t gcc2_compiled.0000000c T go__3Foo0000002c T go__3Fooi00000038 T main</pre></td></tr></table></P><P>Even though <CODE>Foo</CODE> contains two methods with the same name, theirargument lists (one taking an <CODE>int</CODE>, one taking no arguments) helpto differentiate them once their names are mangled. The<SAMP>`go__3Fooi'</SAMP> is the version which takes an <CODE>int</CODE> argument. The<SAMP>`__3Foo'</SAMP> symbol is the constructor for <CODE>Foo</CODE>. The GNUbinutils package includes a utility called <CODE>c++filt</CODE> that candemangle names. Other proprietary tools sometimes include a similarutility, although with a bit of imagination, you can often demanglenames in your head.</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>$ nm --defined-only example.o | c++filt00000000 T Foo::Foo(void)00000000 ? __FRAME_BEGIN__00000000 t gcc2_compiled.0000000c T Foo::go(void)0000002c T Foo::go(int)00000038 T main</pre></td></tr></table></P><P>Name mangling algorithms differ between C++ implementations so thatobject files assembled by one tool chain may not be linked by another ifthere are legitimate reasons to prohibit linking. This is a deliberatemove, as other aspects of the object file may make themincompatible--such as the calling convention used for making functioncalls.</P><P>This implies that C++ libraries and packages cannot be practicallydistributed in binary form. Of course, you were intending to distributethe source code to your package anyway, weren't you?</P><P><A NAME="How GNU Autotools Can Help"></A></TR></TABLE><BR> <FONT SIZE="-1">This document was generatedby <I>Gary V. Vaughan</I> on <I>September, 12 2004</I>using <A HREF="http://www.mathematik.uni-kl.de/~obachman/Texi2html"><I>texi2html</I></A></BODY></HTML>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -