The --combine option fails to forget the "once" property of a header file when
gcc moves on to dealing with the next *.c file. The pragma should function just
the same as the usual "#ifndef _SOME_ARBITRARY_CRAP" hack.
k 0 $ cat once.h
#pragma once
#define D
k 0 $ cat a.c
#include "once.h"
#ifndef D
#error No def in a.c!
#endif
k 0 $ cat b.c
#include "once.h"
#ifndef D
#error No def in b.c!
#endif
k 0 $ gcc --combine a.c b.c
b.c:3:2: error: #error No def in b.c!
k 1 $ gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic
--host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.1 20060828 (Red Hat 4.1.1-20)
k 0 $
--
Summary: --combine can't handle #pragma once
Product: gcc
Version: 4.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: acahalan at gmail dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29172
