Re: [Qemu-devel] [PATCH for-2.0] configure: use do_cc when checking for -fstack-protector support

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 04/11/2014 10:34 PM, Alexey Kardashevskiy wrote:
> On 04/09/2014 09:04 PM, Peter Maydell wrote:
>> MacOSX clang silently swallows unrecognized -f options when doing a link
>> with '-framework' also on the command line, so to detect support for
>> the various -fstack-protector options we must do a plain .c to .o compile,
>> not a complete compile-and-link.
>>
>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>> ---
>> This should be a pretty safe change and it prevents clang/MacOSX
>> builds from spewing a warning on every C file compilation, so I'd
>> like to get it into 2.0.
>>
>>  configure | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/configure b/configure
>> index eb0e7bb..c85475f 100755
>> --- a/configure
>> +++ b/configure
>> @@ -1448,7 +1448,7 @@ done
>>  if test "$stack_protector" != "no" ; then
>>    gcc_flags="-fstack-protector-strong -fstack-protector-all"
>>    for flag in $gcc_flags; do
>> -    if compile_prog "-Werror $flag" "" ; then
>> +    if do_cc $QEMU_CFLAGS -Werror $flag -c -o $TMPO $TMPC ; then
>>        QEMU_CFLAGS="$QEMU_CFLAGS $flag"
>>        LIBTOOLFLAGS="$LIBTOOLFLAGS -Wc,$flag"
>>        break
>>
> 
> My cross environment fails after this patch on "-fstack-protector-all".
> Without the patch, gcc for test program gets additional "-m64 -g
> -L/home/alexey/crosslib/qemu-build-lib-fc19/usr/lib64" (the last one is
> mine, passed via --extra-ldflags=), fails with an error (below). With the
> patch, the configure script thinks everything is fine and fails on "ERROR:
> zlib check failed".
> 
> Why is this happening? Thanks.


This helps. No idea why. Any ideas? :)

@@ -1448,7 +1452,7 @@ done
 if test "$stack_protector" != "no" ; then
   gcc_flags="-fstack-protector-strong -fstack-protector-all"
   for flag in $gcc_flags; do
-    if do_cc $QEMU_CFLAGS -Werror $flag -c -o $TMPO $TMPC ; then
+    if do_cc $QEMU_CFLAGS -Werror $flag -c -o $TMPO $TMPC "" ; then
       QEMU_CFLAGS="$QEMU_CFLAGS $flag"
       LIBTOOLFLAGS="$LIBTOOLFLAGS -Wc,$flag"
       break




> 
> 
> 
> powerpc64-linux-gcc -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef
> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common
> --sysroot=/home/alexey/crosslib/qemu-build-lib-fc19/ -isystem
> /home/alexey/crosslib/qemu-build-lib-fc19/usr/include -D__EXCEPTIONS
> -D__LONG_DOUBLE_128__ -D__NO_INLINE__ -Wno-redundant-decls
> -Wno-missing-prototypes -Wmissing-include-dirs -Wno-system-headers
> -Wendif-labels -Wmissing-include-dirs -Wempty-body -Wnested-externs
> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers
> -Wold-style-declaration -Wold-style-definition -Wtype-limits -Werror
> -fstack-protector-strong -o /tmp/qemu-conf-24556-2284-15038.exe
> /tmp/qemu-conf-31026-2284-18135.c -m64 -g
> -L/home/alexey/crosslib/qemu-build-lib-fc19/usr/lib64
> powerpc64-linux-gcc: error: unrecognized command line option
> '-fstack-protector-strong'
> powerpc64-linux-gcc -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef
> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common
> --sysroot=/home/alexey/crosslib/qemu-build-lib-fc19/ -isystem
> /home/alexey/crosslib/qemu-build-lib-fc19/usr/include -D__EXCEPTIONS
> -D__LONG_DOUBLE_128__ -D__NO_INLINE__ -Wno-redundant-decls
> -Wno-missing-prototypes -Wmissing-include-dirs -Wno-system-headers
> -Wendif-labels -Wmissing-include-dirs -Wempty-body -Wnested-externs
> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers
> -Wold-style-declaration -Wold-style-definition -Wtype-limits -Werror
> -fstack-protector-all -o /tmp/qemu-conf-24556-2284-15038.exe
> /tmp/qemu-conf-31026-2284-18135.c -m64 -g
> -L/home/alexey/crosslib/qemu-build-lib-fc19/usr/lib64
> /home/system/opt/cross/gcc-4.8.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/4.8.0/../../../../powerpc64-linux/bin/ld:
> cannot find -lssp_nonshared
> /home/system/opt/cross/gcc-4.8.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/4.8.0/../../../../powerpc64-linux/bin/ld:
> cannot find -lssp
> collect2: error: ld returned 1 exit status
> 
> 
> 
> 


-- 
Alexey