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Re: Why is gcc going to default to "GNU dialect of ISO C99?"
- From: Dennis Clarke <dclarke at blastwave dot org>
- To: Alexey Salmin <alexey dot salmin at gmail dot com>
- Cc: gcc-help at gcc dot gnu dot org, dclarke at blastwave dot org, aph at redhat dot com, david dot kirkby at onetel dot net, ams at gnu dot org
- Date: Thu, 11 Feb 2010 08:40:11 -0500 (EST)
- Subject: Re: Why is gcc going to default to "GNU dialect of ISO C99?"
- Reply-to: dclarke at blastwave dot org
> It all reminds me a story when I won a bottle of beer from my
> scientific adviser back in 2005. We had a bet: will gcc compile this
> code:
> #include <stdio.h>
> int main() {
> printf("a");
> int a;
> printf("b");
> return 0;
> }
> He was so sure that gcc won't allow it that didn't ever tried :) Thus,
> I think gnu extensions by default are not so bad :)
>
> Alexey
Let's have a look at that. I don't see any issues really. You call
printf() with a literal string, then define some simple integer, then
print another literal string with a call to printf() and finally return
back to the calling process with a status of 0. Very nice.
$ date
Thu Feb 11 13:28:17 GMT 2010
$ uname -a
SunOS aequitas 5.11 snv_130 i86pc i386 i86pc
$
$ cat /etc/release
Solaris Express Community Edition snv_130 X86
Copyright 2009 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 14 December 2009
$
$ /opt/csw/gcc4/bin/gcc --version
gcc (GCC) 4.3.4
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ ls
sample1.c
$
$ cat -n sample1.c
1 /********************************************************************
2 From "Alexey Salmin" <alexey.salmin@gmail.com> email message
3 posted to gcc-help@gcc.gnu.org Thu, February 11, 2010 04:43
4 Subject Re: Why is gcc going to default to "GNU dialect of ISO C99?"
5
*********************************************************************/
6 #include <stdio.h>
7 int main() {
8 printf("a");
9 int a;
10 printf("b");
11 return 0;
12 }
$
$ /opt/csw/gcc4/bin/gcc -v -std=iso9899:1990 -c -o sample1.o sample1.c
Using built-in specs.
Target: i386-pc-solaris2.10
Configured with: /export/medusa/dclarke/build/GCC/gcc-4.3.4/configure
--build=i386-pc-solaris2.10 --with-gnu-as --with-as=/opt/csw/bin/gas
--without-gnu-ld --with-ld=/usr/ccs/bin/ld --with-cpu-32=i386
--with-cpu-64=opteron --with-arch-32=i386 --with-arch-64=opteron
--enable-stage1-languages=c --enable-nls --with-libiconv-prefix=/opt/csw
--enable-threads=posix --prefix=/opt/csw/gcc4 --with-local-prefix=/opt/csw
--enable-shared --enable-multilib --with-included-gettext
--with-system-zlib --with-gmp=/opt/csw --with-mpfr=/opt/csw
--enable-languages=c,c++,objc,fortran --enable-bootstrap
Thread model: posix
gcc version 4.3.4 (GCC)
COLLECT_GCC_OPTIONS='-v' '-std=iso9899:1990' '-c' '-o' 'sample1.o'
'-mtune=generic'
/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/cc1 -quiet -v
sample1.c -quiet -dumpbase sample1.c -mtune=generic -auxbase-strip
sample1.o -std=iso9899:1990 -version -o /var/tmp//ccGRlbZX.s
ignoring nonexistent directory
"/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../../../i386-pc-solaris2.10/include"
#include "..." search starts here:
#include <...> search starts here:
/opt/csw/include
/opt/csw/gcc4/include
/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/include
/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/include-fixed
/usr/include
End of search list.
GNU C (GCC) version 4.3.4 (i386-pc-solaris2.10)
compiled by GNU C version 4.3.4, GMP version 4.3.1, MPFR version
2.4.2-rc1.
warning: MPFR header version 2.4.2-rc1 differs from library version 2.4.2.
GGC heuristics: --param ggc-min-expand=95 --param ggc-min-heapsize=122687
Compiler executable checksum: 9ba7f205b9cefa6eae48c8f511c89b44
COLLECT_GCC_OPTIONS='-v' '-std=iso9899:1990' '-c' '-o' 'sample1.o'
'-mtune=generic'
/opt/csw/bin/gas -v -V -Qy -s -o sample1.o /var/tmp//ccGRlbZX.s
GNU assembler version 2.19.1 (i386-pc-solaris2.8) using BFD version (GNU
Binutils) 2.19.1
COMPILER_PATH=/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/:/usr/ccs/bin/
LIBRARY_PATH=/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-std=iso9899:1990' '-c' '-o' 'sample1.o'
'-mtune=generic'
$
$ ls -lap
total 8
drwxr-xr-x 2 dclarke csw 512 Feb 11 13:29 ./
drwxr-xr-x 3 dclarke csw 512 Feb 11 13:23 ../
-rw-r--r-- 1 dclarke csw 420 Feb 11 13:28 sample1.c
-rw-r--r-- 1 dclarke csw 712 Feb 11 13:29 sample1.o
$ /opt/csw/gcc4/bin/gcc -v -std=iso9899:1990 -o sample1 sample1.o
Using built-in specs.
Target: i386-pc-solaris2.10
Configured with: /export/medusa/dclarke/build/GCC/gcc-4.3.4/configure
--build=i386-pc-solaris2.10 --with-gnu-as --with-as=/opt/csw/bin/gas
--without-gnu-ld --with-ld=/usr/ccs/bin/ld --with-cpu-32=i386
--with-cpu-64=opteron --with-arch-32=i386 --with-arch-64=opteron
--enable-stage1-languages=c --enable-nls --with-libiconv-prefix=/opt/csw
--enable-threads=posix --prefix=/opt/csw/gcc4 --with-local-prefix=/opt/csw
--enable-shared --enable-multilib --with-included-gettext
--with-system-zlib --with-gmp=/opt/csw --with-mpfr=/opt/csw
--enable-languages=c,c++,objc,fortran --enable-bootstrap
Thread model: posix
gcc version 4.3.4 (GCC)
COMPILER_PATH=/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/:/usr/ccs/bin/
LIBRARY_PATH=/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-std=iso9899:1990' '-o' 'sample1' '-mtune=generic'
/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/collect2 -V -Y
P,/usr/ccs/lib:/usr/lib -Qy -o sample1 /usr/lib/crt1.o /usr/lib/crti.o
/usr/lib/values-Xa.o
/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/crtbegin.o
-L/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4
-L/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../.. sample1.o
-lgcc -lgcc_eh -lc -lgcc -lgcc_eh
/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/crtend.o /usr/lib/crtn.o
ld: Software Generation Utilities - Solaris Link Editors: 5.11-1.1688
$
$ ls -lap
total 24
drwxr-xr-x 2 dclarke csw 512 Feb 11 13:30 ./
drwxr-xr-x 3 dclarke csw 512 Feb 11 13:23 ../
-rwxr-xr-x 1 dclarke csw 8096 Feb 11 13:30 sample1
-rw-r--r-- 1 dclarke csw 420 Feb 11 13:28 sample1.c
-rw-r--r-- 1 dclarke csw 712 Feb 11 13:29 sample1.o
$
$ elfdump -d sample1
Dynamic Section: .dynamic
index tag value
[0] NEEDED 0x1e8 libc.so.1
[1] INIT 0x8050d20
[2] FINI 0x8050d40
[3] HASH 0x8050144
[4] STRTAB 0x80504f4
[5] STRSZ 0x40e
[6] SYMTAB 0x8050304
[7] SYMENT 0x10
[8] SUNW_SYMTAB 0x8050244
[9] SUNW_SYMSZ 0x2b0
[10] SUNW_SORTENT 0x4
[11] SUNW_SYMSORT 0x8050974
[12] SUNW_SYMSORTSZ 0x3c
[13] CHECKSUM 0x6176
[14] VERNEED 0x8050904
[15] VERNEEDNUM 0x1
[16] PLTRELSZ 0x40
[17] PLTREL 0x11
[18] JMPREL 0x80509d8
[19] REL 0x80509b0
[20] RELSZ 0x68
[21] RELENT 0x8
[22] DEBUG 0
[23] FEATURE_1 0x1 [ PARINIT ]
[24] SUNW_CAP 0x8050128
[25] FLAGS 0 0
[26] FLAGS_1 0 0
[27] SUNW_STRPAD 0x200
[28] SUNW_LDMACH 0x3 EM_386
[29] PLTGOT 0x8060d5c
[30-40] NULL 0
$
$ ./sample1
ab$
$
$ ./sample1 | od -Ax -t x1
0000000 61 62
0000002
$
No problem there at all.
Let's try the same thing with Sun Studio 12 on Solaris 10 :
$ uname -a
SunOS vanth 5.10 Generic_142901-03 i86pc i386 i86pc
$ cat /etc/release
Solaris 10 5/09 s10x_u7wos_08 X86
Copyright 2009 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 30 March 2009
$
$ which cc
/opt/studio/SOS12/SUNWspro/bin/cc
$
$ cc -V
cc: Sun C 5.9 SunOS_i386 Patch 124868-11 2009/11/21
usage: cc [ options] files. Use 'cc -flags' for details
$
$ ls
sample1.c
$
$ cc -\# -H -Qy -Xc -xbuiltin=%none -Kpic -xildoff -xregs=no%frameptr -xs
-xstrconst -g -D_TS_ERRNO -D_POSIX_SOURCE -c -o sample1.o sample1.c
### Note: NLSPATH =
/opt/studio/SOS12/SUNWspro/prod/bin/../lib/locale/%L/LC_MESSAGES/%N.cat:/opt/studio/SOS12/SUNWspro/prod/bin/../../lib/locale/%L/LC_MESSAGES/%N.cat
### command line files and options (expanded):
### -c -D_TS_ERRNO -D_POSIX_SOURCE -g -H -Kpic -Xc -features=no%typeof
-xregs=no%frameptr -xs -xstrconst sample1.c -o sample1.o
/opt/studio/SOS12/SUNWspro/prod/bin/acomp -dg -xldscope=global -i
sample1.c -y-fbe -y/opt/studio/SOS12/SUNWspro/prod/bin/fbe -y-pic
-y-xarch=generic -y-g -y-o -ysample1.o -y-verbose -y-xthreadvar=dynamic
-y-comdat -xdbggen=no%stabs+dwarf2+usedonly -H -strconst -D_TS_ERRNO
-D_POSIX_SOURCE -xdbggen=incl -y-s -2k -m32 -fparam_ir -Qy -D__SunOS_5_10
-D__SUNPRO_C=0x590 -D__SVR4 -D__sun -D__SunOS -D__unix -D__i386
-D__BUILTIN_VA_ARG_INCR -D__C99FEATURES__ -Xc -D__PRAGMA_REDEFINE_EXTNAME
-xc99=%all,no%lib -D__FLT_EVAL_METHOD__=-1 -features=no%typeof
-I/opt/studio/SOS12/SUNWspro/prod/include/cc
"-g/opt/studio/SOS12/SUNWspro/prod/bin/cc -H -Qy -Xc -xbuiltin=%none -Kpic
-xildoff -xregs=no%frameptr -xs -xstrconst -g -D_TS_ERRNO -D_POSIX_SOURCE
-c -o sample1.o " -fsimple=0 -D__SUN_PREFETCH -destination_ir=yabe
/usr/include/stdio.h
/usr/include/sys/feature_tests.h
/usr/include/sys/ccompile.h
/usr/include/sys/isa_defs.h
/usr/include/iso/stdio_iso.h
/usr/include/sys/va_list.h
/usr/include/stdio_tag.h
/usr/include/stdio_impl.h
/usr/include/iso/stdio_c99.h
/opt/studio/SOS12/SUNWspro/prod/bin/fbe -s -o sample1.o -warn=%none -Qy
/tmp/yabeAAARnaqit
rm /tmp/yabeAAARnaqit
$
$ ls -l
total 3
-rw-r--r-- 1 dclarke csw 420 Feb 11 13:35 sample1.c
-rw-r--r-- 1 dclarke csw 3888 Feb 11 13:37 sample1.o
$
$ cc -\# -H -Qy -Xc -xbuiltin=%none -Kpic -xildoff -xregs=no%frameptr -xs
-xstrconst -g -D_TS_ERRNO -D_POSIX_SOURCE -o sample1 sample1.c
### Note: NLSPATH =
/opt/studio/SOS12/SUNWspro/prod/bin/../lib/locale/%L/LC_MESSAGES/%N.cat:/opt/studio/SOS12/SUNWspro/prod/bin/../../lib/locale/%L/LC_MESSAGES/%N.cat
### command line files and options (expanded):
### -D_TS_ERRNO -D_POSIX_SOURCE -g -H -Kpic -Xc -features=no%typeof
-xregs=no%frameptr -xs -xstrconst sample1.c -o sample1
/opt/studio/SOS12/SUNWspro/prod/bin/acomp -dg -xldscope=global -i
sample1.c -y-fbe -y/opt/studio/SOS12/SUNWspro/prod/bin/fbe -y-pic
-y-xarch=generic -y-g -y-o -ysample1.o -y-verbose -y-xthreadvar=dynamic
-y-comdat -xdbggen=no%stabs+dwarf2+usedonly -H -strconst -D_TS_ERRNO
-D_POSIX_SOURCE -xdbggen=incl -y-s -2k -m32 -fparam_ir -Qy -D__SunOS_5_10
-D__SUNPRO_C=0x590 -D__SVR4 -D__sun -D__SunOS -D__unix -D__i386
-D__BUILTIN_VA_ARG_INCR -D__C99FEATURES__ -Xc -D__PRAGMA_REDEFINE_EXTNAME
-xc99=%all,no%lib -D__FLT_EVAL_METHOD__=-1 -features=no%typeof
-I/opt/studio/SOS12/SUNWspro/prod/include/cc
"-g/opt/studio/SOS12/SUNWspro/prod/bin/cc -H -Qy -Xc -xbuiltin=%none -Kpic
-xildoff -xregs=no%frameptr -xs -xstrconst -g -D_TS_ERRNO -D_POSIX_SOURCE
-c " -fsimple=0 -D__SUN_PREFETCH -destination_ir=yabe
/usr/include/stdio.h
/usr/include/sys/feature_tests.h
/usr/include/sys/ccompile.h
/usr/include/sys/isa_defs.h
/usr/include/iso/stdio_iso.h
/usr/include/sys/va_list.h
/usr/include/stdio_tag.h
/usr/include/stdio_impl.h
/usr/include/iso/stdio_c99.h
/opt/studio/SOS12/SUNWspro/prod/bin/fbe -s -o sample1.o -warn=%none -Qy
/tmp/yabeAAA_BaWit
rm /tmp/yabeAAA_BaWit
### Note: LD_LIBRARY_PATH = <null>
### Note: LD_RUN_PATH = <null>
/usr/ccs/bin/ld /opt/studio/SOS12/SUNWspro/prod/lib/crti.o
/opt/studio/SOS12/SUNWspro/prod/lib/crt1.o
/opt/studio/SOS12/SUNWspro/prod/lib/values-xc.o -o sample1 sample1.o -Y
"P,/opt/studio/SOS12/SUNWspro/prod/lib:/usr/ccs/lib:/lib:/usr/lib" -Qy -lc
/opt/studio/SOS12/SUNWspro/prod/lib/crtn.o
$
$ ls -l
total 3
-rwxr-xr-x 1 dclarke csw 7520 Feb 11 13:37 sample1
-rw-r--r-- 1 dclarke csw 420 Feb 11 13:35 sample1.c
$
$ file sample1
sample1: ELF 32-bit LSB executable 80386 Version 1 [FPU], dynamically
linked, not stripped
$
$ elfdump -d sample1
Dynamic Section: .dynamic
index tag value
[0] NEEDED 0x114 libc.so.1
[1] INIT 0x8050738
[2] FINI 0x8050754
[3] RUNPATH 0x13a /opt/csw/lib/amd64
[4] RPATH 0x13a /opt/csw/lib/amd64
[5] HASH 0x8050118
[6] STRTAB 0x805039c
[7] STRSZ 0x14d
[8] SYMTAB 0x80501fc
[9] SYMENT 0x10
[10] CHECKSUM 0x7ef0
[11] VERNEED 0x80504ec
[12] VERNEEDNUM 0x1
[13] PLTRELSZ 0x30
[14] PLTREL 0x11
[15] JMPREL 0x8050524
[16] REL 0x805051c
[17] RELSZ 0x38
[18] RELENT 0x8
[19] DEBUG 0
[20] FEATURE_1 0x1 [ PARINIT ]
[21] SUNW_CAP 0x8050108
[22] FLAGS 0 0
[23] FLAGS_1 0 0
[24] PLTGOT 0x806077c
[25] NULL 0
$
$ ./sample1
ab$
$
$ ./sample1 | od -Ax -t x1
0000000 61 62
0000002
$
No problems there either.
--
Dennis Clarke
dclarke@opensolaris.ca <- Email related to the open source Solaris
dclarke@blastwave.org <- Email related to open source for Solaris