[BUILDROBOT] Still warns on integer overflow in expression (was: gas: microblaze: fix shift overflow)

[Jan-Benedict Glaw]

On Sun, 2015-11-15 02:49:03 -0500, Mike Frysinger <vapier@gentoo.org> wrote:
> This code tries to shift an integer 31 bits which triggers a werror:
> gas/config/tc-microblaze.c:742:21: error: integer overflow in expression [-Werror=overflow]
>   e->X_add_number |= -(1 << 31);
> 
> Cast the 1 to offsetT to match X_add_number to fix things.
> 
> 2015-11-15  Mike Frysinger  <vapier@gentoo.org>
> 
> 	* config/tc-microblaze.c (parse_imm): Add an offsetT cast.
>  gas/config/tc-microblaze.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gas/config/tc-microblaze.c b/gas/config/tc-microblaze.c
> index ac7c828..0ec24f8 100644
> --- a/gas/config/tc-microblaze.c
> +++ b/gas/config/tc-microblaze.c
> @@ -739,7 +739,7 @@ parse_imm (char * s, expressionS * e, offsetT min, offsetT max)
>      {
>        /* Special case: sign extend negative 32-bit values to 64-bits.  */
>        if ((e->X_add_number >> 31) == 1)
> -	e->X_add_number |= -(1 << 31);
> +	e->X_add_number |= -((offsetT) 1 << 31);
>  
>        if (e->X_add_number < min || e->X_add_number > max)
>  	{

Even with this cast in place, gcc111 still warns on this:

jbglaw@power-aix:~$ gcc --version
gcc (GCC) 4.8.1
Copyright (C) 2013 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.


Build log can be found at
http://toolchain.lug-owl.de/buildbot/show_build_details.php?id=484233 :

gcc -DHAVE_CONFIG_H -I. -I/home/jbglaw/repos/binutils_gdb/gas  -I. -I/home/jbglaw/repos/binutils_gdb/gas -I../bfd -I/home/jbglaw/repos/binutils_gdb/gas/config -I/home/jbglaw/repos/binutils_gdb/gas/../include -I/home/jbglaw/repos/binutils_gdb/gas/.. -I/home/jbglaw/repos/binutils_gdb/gas/../bfd -DLOCALEDIR="\"/home/jbglaw/build/microblaze-linux/_install_/share/locale\""  -W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -Werror -I/home/jbglaw/repos/binutils_gdb/gas/../zlib -g -O2 -MT tc-microblaze.o -MD -MP -MF .deps/tc-microblaze.Tpo -c -o tc-microblaze.o `test -f 'config/tc-microblaze.c' || echo '/home/jbglaw/repos/binutils_gdb/gas/'`config/tc-microblaze.c
/home/jbglaw/repos/binutils_gdb/gas/config/tc-microblaze.c: In function 'parse_imm':
/home/jbglaw/repos/binutils_gdb/gas/config/tc-microblaze.c:742:21: error: integer overflow in expression [-Werror=overflow]
  e->X_add_number |= -((offsetT) 1 << 31);
                     ^
cc1: all warnings being treated as errors
make[3]: *** [tc-microblaze.o] Error 1
make[3]: Leaving directory `/home/jbglaw/build/microblaze-linux/build-binutils-full/gas'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/jbglaw/build/microblaze-linux/build-binutils-full/gas'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/home/jbglaw/build/microblaze-linux/build-binutils-full/gas'
make: *** [all-gas] Error 2


MfG, JBG

-- 
      Jan-Benedict Glaw      jbglaw@lug-owl.de              +49-172-7608481
Signature of:           Ich hatte in letzter Zeit ein bißchen viel Realitycheck.
the second  :               Langsam möchte ich mal wieder weiterträumen können.
                             -- Maximilian Wilhelm (18. Mai 2005, #lug-owl.de)
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