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<!DOCTYPE HTML PUBLIC "-//W3O//DTD W3 HTML 2.0//EN"><!-- This collection of hypertext pages is Copyright 1995-2005 by Steve Summit. --><!-- Content from the book "C Programming FAQs: Frequently Asked Questions" --><!-- (Addison-Wesley, 1995, ISBN 0-201-84519-9) is made available here by --><!-- permission of the author and the publisher as a service to the community. --><!-- It is intended to complement the use of the published text --><!-- and is protected by international copyright laws. --><!-- The on-line content may be accessed freely for personal use --><!-- but may not be published or retransmitted without explicit permission. --><!-- --><!-- this page built Sat Dec 24 21:47:46 2005 by faqproc version 2.7 --><!-- from source file ansi.sgml dated Wed Aug 11 00:43:45 2004 --><!-- corresponding to FAQ list version 4.0 --><html><!-- Mirrored from c-faq.com/ansi/preansi.html by HTTrack Website Copier/3.x [XR&CO'2008], Sat, 14 Mar 2009 07:58:56 GMT --><head><meta name=GENERATOR content="faqproc"><title>Question 11.29a</title><link href="noalias.html" rev=precedes><link href="preansi2.html" rel=precedes><link href="index.html" rev=subdocument></head><body bgcolor="#ffffff"><a href="noalias.html" rev=precedes><img src="../images/buttonleft.gif" alt="prev"></a><a href="index.html" rev=subdocument><img src="../images/buttonup.gif" alt="up"></a><a href="preansi2.html" rel=precedes><img src="../images/buttonright.gif" alt="next"></a> <a href="../index-2.html"><img src="../images/buttontop.gif" alt="top/contents"></a><a href="../search.html"><img src="../images/buttonsrch.gif" alt="search"></a><hr><p><!-- qbegin --><h1>comp.lang.c FAQ list<font color=blue>·</font><!-- qtag -->Question 11.29a</h1><p><font face=Helvetica size=8 color=blue><b>Q:</b></font>My compiler is rejecting the simplest possible test programs,with all kinds of syntax errors.It's complaining about thefirst line of<pre> main(int argc, char **argv) { return 0; }</pre></p><p><hr><p><font face=Helvetica size=8 color=blue><b>A:</b></font>Perhaps it is a pre-ANSI compiler,unable to accept function prototypes and the like.</p><p>See also questions<a href="../decl/autoaggrinit.html">1.31</a>,<a href="../cpp/headerglom.html">10.9</a>,<a href="preansilib.html">11.30</a>,and<a href="../strangeprob/unclosed.html">16.1b</a>.</p><p>If you don't have access to an ANSI compiler,and you need to convert some newer code(such as that in this list)so that you can compile it,perform these steps:</p><OL><li>Removethe argument type information fromfunction prototype declarations,and convert prototype-style function definitions to old style.The new-style declarations<pre> extern int f1(void); extern int f2(int); int main(int argc, char **argv) { ... } int f3(void) { ... }</pre>would berewritten as<pre> extern int f1(); extern int f2(); int main(argc, argv) int argc; char **argv; { ... } int f3() { ... }</pre>(Bewareof parameters with ``narrow'' types;see question <a href="argpromos.html">11.3</a>.)<li>Replace <TT>void *</TT> with <TT>char *</TT>.<li>Perhaps insert explicit casts where converting between``generic'' pointers(<TT>void *</TT>, which you've just replaced with <TT>char *</TT>)and other pointer types(for instance in calls to <TT>malloc</TT> and <TT>free</TT>,and in <TT>qsort</TT> comparison functions;see questions <a href="../malloc/cast.html">7.7</a> and <a href="../lib/qsort2.html">13.9</a>).<li>Insert casts when passing the ``wrong'' numerictypes as function arguments, e.g. <TT>sqrt((double)i);</TT>.<li>Rework calls to <TT>realloc</TT>that use <TT>NULL</TT> or <TT>0</TT> as first or second arguments(see question <a href="../malloc/reallocnull.html">7.30</a>).<li>Remove <TT>const</TT> and <TT>volatile</TT> qualifiers.<li>Modify any initialized automatic aggregates(see question <a href="../decl/autoaggrinit.html">1.31</a>).<li>Use older library functions(see question <a href="../lib/oldlibfcns.html">13.24</a>).<li>Re-work any preprocessor macros involving <TT>#</TT> or <TT>##</TT>(see questions <a href="../cpp/oldpaste.html">10.20</a>, <a href="../cpp/charize.html">10.21</a>,and <a href="macstrexp.html">11.18</a>).<li>Rework conditional compilationinvolving <TT>#elif</TT>.<li>Convert from the facilities of <TT><stdarg.h></TT>to <TT><varargs.h></TT>(see question <a href="../varargs/oldvarargs.html">15.7</a>).<li>Cross your fingers.(In other words, thesteps listed hereare not alwayssufficient;more complicated changes may be required which aren't covered by any cookbook conversions.)</OL><p>It is possible to make many of these changes with the preprocessorrather than by editing source code.</p><p>See also theRationale's list of ``quiet changes''(see question <a href="avail.html">11.2</a>).</p><p>See also question <a href="cproto.html">11.31</a>.</p><!-- aend --><p><hr><a href="noalias.html" rev=precedes><img src="../images/buttonleft.gif" alt="prev"></a><a href="index.html" rev=subdocument><img src="../images/buttonup.gif" alt="up"></a><a href="preansi2.html" rel=precedes><img src="../images/buttonright.gif" alt="next"></a> <a href="../questions.html"><img src="../images/buttontop.gif" alt="contents"></a><a href="../search.html"><img src="../images/buttonsrch.gif" alt="search"></a><br><!-- lastfooter --><a href="../about.html">about this FAQ list</a> <a href="../eskimo.html">about eskimo</a> <a href="../search.html">search</a> <a href="../feedback.html">feedback</a> <a href="copyright.html">copyright</a><p>Hosted by<a href="http://www.eskimo.com/"><img src="../../www.eskimo.com/img/link/eskitiny.gif" alt="Eskimo North"></a></body><!-- Mirrored from c-faq.com/ansi/preansi.html by HTTrack Website Copier/3.x [XR&CO'2008], Sat, 14 Mar 2009 07:58:56 GMT --></html>⌨️ 快捷键说明
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