2008/12/16 Dennis Clarke <dcla...@blastwave.org>:
>
>> Hi,
>>
>> The following program segfaults when compiled with gcc
>> but runs fine when compiled with g++ or icc (the intel C compiler)
>>
>> #include <stdio.h>
>> struct Hello {
>> char world[20];
>> };
>> struct Hello s(){
>> struct Hello r;
>> r.world[0]='H';
>> r.world[1]='\0';
>> return r;
>> }
>>
>> int main(){
>> printf("%s\n",s().world);
>> }
>>
>> Assigning s() to a variable and then using the variable avoids the
>> segfault.
>
> compiles and works fine with GCC 4.3.2 on Solaris 8/9/10 sun4m/sun4u/i386
>
> $ /opt/csw/gcc4/bin/gcc -v -o foo.o -c foo.c
> Using built-in specs.
> Target: sparc-sun-solaris2.8
> Configured with: ../gcc-4.3.2/configure --prefix=/opt/csw/gcc4
> --with-local-prefix=/opt/csw --with-as=/usr/ccs/bin/as --without-gnu-ld
> --with-ld=/usr/ccs/bin/ld --with-cpu=v7 --enable-threads=posix
> --enable-nls --enable-shared --enable-languages=c,c++,fortran,objc
> --with-gmp=/opt/csw --with-mpfr=/opt/csw --enable-multilib
> --with-included-gettext --with-libiconv-prefix=/opt/csw --with-x
> --enable-java-awt=xlib --with-system-zlib --enable-bootstrap
> Thread model: posix
> gcc version 4.3.2 (GCC)
> COLLECT_GCC_OPTIONS='-v' '-o' 'foo.o' '-c' '-mcpu=v7'
> /opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/cc1 -quiet -v foo.c
> -quiet -dumpbase foo.c -mcpu=v7 -auxbase-strip foo.o -version -o
> /var/tmp//ccAHrz2q.s
> ignoring nonexistent directory
> "/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/../../../../sparc-sun-solaris2.8/include"
> #include "..." search starts here:
> #include <...> search starts here:
> /opt/csw/include
> /opt/csw/gcc4/include
> /opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/include
> /opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/include-fixed
> /usr/include
> End of search list.
> GNU C (GCC) version 4.3.2 (sparc-sun-solaris2.8)
> compiled by GNU C version 4.3.2, GMP version 4.2.2, MPFR version
> 2.3.1.
> warning: GMP header version 4.2.2 differs from library version 4.2.4.
> GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=32768
> Compiler executable checksum: 1ac791ab3c2b7cc8775dc74d45095fef
> COLLECT_GCC_OPTIONS='-v' '-o' 'foo.o' '-c' '-mcpu=v7'
> /usr/ccs/bin/as -V -Qy -s -xarch=v8 -o foo.o /var/tmp//ccAHrz2q.s
> /usr/ccs/bin/as: Sun WorkShop 6 2003/12/18 Compiler Common 6.0 Patch
> 114802-02
> COMPILER_PATH=/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/:/usr/ccs/bin/
> LIBRARY_PATH=/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/:/usr/ccs/lib/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/../../../:/lib/:/usr/lib/
> COLLECT_GCC_OPTIONS='-v' '-o' 'foo.o' '-c' '-mcpu=v7'
>
> $ /opt/csw/gcc4/bin/gcc -v -o foo.s -S -c foo.c
> Using built-in specs.
> Target: sparc-sun-solaris2.8
> Configured with: ../gcc-4.3.2/configure --prefix=/opt/csw/gcc4
> --with-local-prefix=/opt/csw --with-as=/usr/ccs/bin/as --without-gnu-ld
> --with-ld=/usr/ccs/bin/ld --with-cpu=v7 --enable-threads=posix
> --enable-nls --enable-shared --enable-languages=c,c++,fortran,objc
> --with-gmp=/opt/csw --with-mpfr=/opt/csw --enable-multilib
> --with-included-gettext --with-libiconv-prefix=/opt/csw --with-x
> --enable-java-awt=xlib --with-system-zlib --enable-bootstrap
> Thread model: posix
> gcc version 4.3.2 (GCC)
> COLLECT_GCC_OPTIONS='-v' '-o' 'foo.s' '-S' '-c' '-mcpu=v7'
> /opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/cc1 -quiet -v foo.c
> -quiet -dumpbase foo.c -mcpu=v7 -auxbase-strip foo.s -version -o foo.s
> ignoring nonexistent directory
> "/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/../../../../sparc-sun-solaris2.8/include"
> #include "..." search starts here:
> #include <...> search starts here:
> /opt/csw/include
> /opt/csw/gcc4/include
> /opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/include
> /opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/include-fixed
> /usr/include
> End of search list.
> GNU C (GCC) version 4.3.2 (sparc-sun-solaris2.8)
> compiled by GNU C version 4.3.2, GMP version 4.2.2, MPFR version
> 2.3.1.
> warning: GMP header version 4.2.2 differs from library version 4.2.4.
> GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=32768
> Compiler executable checksum: 1ac791ab3c2b7cc8775dc74d45095fef
> COMPILER_PATH=/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/libexec/gcc/sparc-sun-solaris2.8/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/:/usr/ccs/bin/
> LIBRARY_PATH=/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/:/usr/ccs/lib/:/opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/../../../:/lib/:/usr/lib/
> COLLECT_GCC_OPTIONS='-v' '-o' 'foo.s' '-S' '-c' '-mcpu=v7'
>
> $ cat foo.s
> .file "foo.c"
> .section ".text"
> .align 4
> .global s
> .type s, #function
> .proc 010
> s:
> save %sp, -136, %sp
> ld [%fp+64], %l0
> mov 72, %g1
> stb %g1, [%fp-36]
> stb %g0, [%fp-35]
> mov %l0, %g1
> add %fp, -36, %g2
> mov 20, %g3
> mov %g1, %o0
> mov %g2, %o1
> mov %g3, %o2
> call memcpy, 0
> nop
> mov %l0, %i0
> restore
> jmp %o7+12
> nop
> .size s, .-s
> .section ".rodata"
> .align 8
> .LLC0:
> .asciz "%s\n"
> .section ".text"
> .align 4
> .global main
> .type main, #function
> .proc 04
> main:
> save %sp, -168, %sp
> add %fp, -36, %g1
> st %g1, [%sp+64]
> call s, 0
> nop
> unimp 20
> ld [%fp-36], %g1
> st %g1, [%fp-64]
> ld [%fp-32], %g1
> st %g1, [%fp-60]
> ld [%fp-28], %g1
> st %g1, [%fp-56]
> ld [%fp-24], %g1
> st %g1, [%fp-52]
> ld [%fp-20], %g1
> st %g1, [%fp-48]
> add %fp, -64, %g2
> sethi %hi(.LLC0), %g1
> or %g1, %lo(.LLC0), %o0
> mov %g2, %o1
> call printf, 0
> nop
> restore
> jmp %o7+8
> nop
> .size main, .-main
> .ident "GCC: (GNU) 4.3.2"
> $
> $
> $ /opt/csw/gcc4/bin/gcc -o foo foo.s
> $ ./foo
> H
>
> works right ?
>
> Dennis Clarke
> http://www.blastwave.org/
>
>
sal...@salmin:~/testdir/c$ gcc string_hello.c -o string_hello
sal...@salmin:~/testdir/c$ ./string_hello
эW°▒Ъ
It's not a segfault but obviously a wrong behavior.
gcc version 4.3.2 (Debian 4.3.2-1)
Linux salmin 2.6.26-1-amd64 #1 SMP Sat Nov 8 18:25:23 UTC 2008 x86_64 GNU/Linux
