Bug#410066: gcc-4.1: inconsistency of char signedness between different platforms

[Bin Tian <tianbin@cernet.edu.cn>]

Package: gcc-4.1
Version: 4.1.1-21
Severity: normal

Hi, 

The following code produce different outputs on x86 platform and powerpc
platform:

~$ cat a.c

#include <stdio.h>
int main (void)
{
  char ch [2] = { 127, 180 };
  signed char sch [2] = { 127, 180 };
  unsigned uch [2] = { 127, 180 };

  printf ("char: %d %d\n", ch[0], ch[1]);
  printf ("signed char: %d %d\n", sch[0], sch[1]);
  printf ("unsigned char: %d %d\n", uch[0], uch[1]);
};

x86 or x64 platform, it outputs:
~$ ./a.out
char: 127 -76
signed char: 127 -76
unsigned char: 127 180

powerpc platform, it outputs:
~$ ./a.out
char: 127 180
signed char: 127 -76
unsigned char: 127 180


a.c is compiled by `gcc a.c`

I found this problem when checking the fcitx crash problem on ppc
platform. After a deep digging, I found the problem was caused by the
default signedness of char. 

After adding `signed` to force the compiler use the singed char, fcitx
works well on ppc.

I found the fcitx crashing prolem on ppc more than 3 months ago. I
had no time to report it till today. So this problem has been there for
more than 3 months. 

I'm not quite sure if the debian building system is using gcc-4.1. But
apprently this problem exists in the gcc which debian building system
is using.

There may be other packages affected by this problem.

Best Regards, 
Bin Tian

-- System Information:
Debian Release: 4.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-3-amd64
Locale: LANG=zh_CN, LC_CTYPE=zh_CN (charmap=GB2312)

Versions of packages gcc-4.1 depends on:
ii  binutils                    2.17-3       The GNU assembler, linker and bina
ii  cpp-4.1                     4.1.1-21     The GNU C preprocessor
ii  gcc-4.1-base                4.1.1-21     The GNU Compiler Collection (base 
ii  libc6                       2.3.6.ds1-10 GNU C Library: Shared libraries
ii  libgcc1                     1:4.1.1-21   GCC support library
ii  libssp0                     4.1.1-21     GCC stack smashing protection libr

Versions of packages gcc-4.1 recommends:
ii  libc6-dev                   2.3.6.ds1-10 GNU C Library: Development Librari
pn  libmudflap0-dev             <none>       (no description available)

-- no debconf information