gcc-3.3: I think sizeof(struct xxx) return wrong size

[Debian Bug Importer]

Automatically imported from Debian bug report #286239 http://bugs.debian.org/286239

[Debian Bug Importer (debzilla)]

Automatically imported from Debian bug report #286239 http://bugs.debian.org/286239

[Debian Bug Importer (debzilla)]

Message-Id: <email address hidden>
Date: Sat, 18 Dec 2004 20:00:40 +0200
From: BogDan <email address hidden>
To: Debian Bug Tracking System <email address hidden>
Subject: gcc-3.3: I think sizeof(struct xxx) return wrong size

Package: gcc-3.3
Version: 1:3.3.5-3
Severity: critical
Justification: causes serious data loss

try to compile and run this

//-------------------------------
#include <stdio.h>

int main()
{
struct mesaj_primire
{
        unsigned char xf;
        unsigned char cf;
        unsigned char nw;
        unsigned char nl;
        unsigned int posx;
        unsigned int posy;
        unsigned int state;
        unsigned char nwc;
        unsigned char nlc;
        unsigned char crc;
        unsigned short crc16;
};
printf("%i\n",sizeof(mesaj_primire));
return 0;
}

//---------------------------------
#gcc test.cpp -lstdc++ -o test
#./test
24

24!!!! and I think is 21

I try this on my ppc laptop and my x86 desktop and the result is the same (24)

taipan:/# uname -a;gcc -v
Linux taipan 2.6.8.1 #3 Wed Oct 27 18:29:21 EEST 2004 ppc GNU/Linux
Reading specs from /usr/lib/gcc-lib/powerpc-linux/3.3.5/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,pascal,objc,ada --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-debug --enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc --disable-multilib powerpc-linux
Thread model: posix
gcc version 3.3.5 (Debian 1:3.3.5-3)
taipan:/#

root@taipan:/# uname -a;gcc -v
Linux taipan 2.6.4 #1 SMP Sun Sep 19 19:28:30 EEST 2004 i686 GNU/Linux
Reading specs from /usr/lib/gcc-lib/i486-linux/3.3.5/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-debug --enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc i486-linux
Thread model: posix
gcc version 3.3.5 (Debian 1:3.3.5-4)
root@taipan:/#

-- System Information:
Debian Release: 3.1
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: powerpc (ppc)
Kernel: Linux 2.6.8.1
Locale: LANG=ro_RO, LC_CTYPE=ro_RO (charmap=ISO-8859-2)

Versions of packages gcc-3.3 depends on:
ii binutils 2.15-5 The GNU assembler, linker and bina
ii cpp-3.3 1:3.3.5-3 The GNU C preprocessor
ii gcc-3.3-base 1:3.3.5-3 The GNU Compiler Collection (base
ii libc6 2.3.2.ds1-19 GNU C Library: Shared libraries an
ii libgcc1 1:3.4.3-4 GCC support library

-- no debconf information

[Falk Hueffner (falk)]

BogDan <email address hidden>, <email address hidden> schrieb am 18.12.04 19:22:37:
>
> Package: gcc-3.3
> Version: 1:3.3.5-3
> Severity: critical
> Justification: causes serious data loss
>
> try to compile and run this
>
> //-------------------------------
> #include <stdio.h>
>
> int main()
> {
> struct mesaj_primire
> {
> unsigned char xf;
> unsigned char cf;
> unsigned char nw;
> unsigned char nl;
> unsigned int posx;
> unsigned int posy;
> unsigned int state;
> unsigned char nwc;
> unsigned char nlc;
> unsigned char crc;
> unsigned short crc16;
> };
> printf("%i\n",sizeof(mesaj_primire));
> return 0;
> }
>
> //---------------------------------
> #gcc test.cpp -lstdc++ -o test
> #./test
> 24
>
> 24!!!! and I think is 21

24 is correct; there needs to be padding to ensure alignment.

Falk

[Debian Bug Importer (debzilla)]

Message-Id: <email address hidden>
Date: Sat, 18 Dec 2004 20:21:42 +0100
From: "Falk Hueffner" <email address hidden>
To: <email address hidden>
Subject: Re: Bug#286239: gcc-3.3: I think sizeof(struct xxx) return wrong size

BogDan <email address hidden>, <email address hidden> schrieb am 18.12.04 19:22:37:
>
> Package: gcc-3.3
> Version: 1:3.3.5-3
> Severity: critical
> Justification: causes serious data loss
>
> try to compile and run this
>
> //-------------------------------
> #include <stdio.h>
>
> int main()
> {
> struct mesaj_primire
> {
> unsigned char xf;
> unsigned char cf;
> unsigned char nw;
> unsigned char nl;
> unsigned int posx;
> unsigned int posy;
> unsigned int state;
> unsigned char nwc;
> unsigned char nlc;
> unsigned char crc;
> unsigned short crc16;
> };
> printf("%i\n",sizeof(mesaj_primire));
> return 0;
> }
>
> //---------------------------------
> #gcc test.cpp -lstdc++ -o test
> #./test
> 24
>
> 24!!!! and I think is 21

24 is correct; there needs to be padding to ensure alignment.

Falk

[Matthias Klose (doko)]

24 is correct; there needs to be padding to ensure alignment.