PATCH: Remove AM_MAKEFLAGS from libsanitizer

[Paolo Bonzini]

Il 12/12/2012 18:30, H.J. Lu ha scritto:
> On Wed, Dec 12, 2012 at 6:46 AM, Paolo Bonzini <bonzini@gnu.org> wrote:
>> Il 12/12/2012 15:41, H.J. Lu ha scritto:
>>> MAKEOVERRIDES is used for multilib.  I got
>>>
>>> /bin/sh ../libtool --tag=CXX   --mode=compile  -D_GNU_SOURCE -D_DEBUG
>>> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
>>> -DASAN_HAS_EXCEPTIONS=1 -DASAN_FLEXIBLE_MAPPING_AND_OFFSET=0
>>> -DASAN_NEEDS_SEGV=1  -I.
>>> -I/export/gnu/import/git/gcc/libsanitizer/asan  -I
>>> /export/gnu/import/git/gcc/libsanitizer/include -I
>>> /export/gnu/import/git/gcc/libsanitizer  -Wall -W
>>> -Wno-unused-parameter -Wwrite-strings -pedantic -Wno-long-long -fPIC
>>> -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables
>>> -fvisibility=hidden -Wno-variadic-macros -Wno-c99-extensions
>>> -I../../libstdc++-v3/include
>>> -I../../libstdc++-v3/include/x86_64-unknown-linux-gnu
>>> -I/export/gnu/import/git/gcc/libsanitizer/../libstdc++-v3/libsupc++ -g
>>> -O2 -D_GNU_SOURCE  -m32 -MT asan_malloc_linux.lo -MD -MP -MF
>>> .deps/asan_malloc_linux.Tpo -c -o asan_malloc_linux.lo
>>> /export/gnu/import/git/gcc/libsanitizer/asan/asan_malloc_linux.cc
>>> libtool: compile: unrecognized option `-D_GNU_SOURCE'
>>> libtool: compile: Try `libtool --help' for more information.
>>> make[8]: *** [asan_allocator.lo] Error 1
>>> make[8]: *** Waiting for unfinished jobs....
>>> libtool: compile: unrecognized option `-D_GNU_SOURCE'
>>> libtool: compile: Try `libtool --help' for more information
>>>
>>> I checked in this patch to restore MAKEOVERRIDES.
>>
>> This will break "make CFLAGS=-g".  Please revert the AM_MAKEFLAGS change
>> fully.
> 
> Done.
> 
>> However, your patch that removed AM_MAKEFLAGS similarly broke "make
>> CC=foo".  While it is much less useful, this nevertheless may be the
>> sign of a bigger problem.  Why did you need to remove CC/CXX from
>> AM_MAKEFLAGS in the first place?
>>
> 
> After further investigation, I found
> 
> RAW_CXX_TARGET_EXPORTS = \
>         $(BASE_TARGET_EXPORTS) \
>         CXX_FOR_TARGET="$(RAW_CXX_FOR_TARGET)"; export CXX_FOR_TARGET; \
>         CXX="$(RAW_CXX_FOR_TARGET) $(XGCC_FLAGS_FOR_TARGET) $$TFLAGS";
> export CXX;
> ...
> 
> all-stage1-target-libsanitizer: configure-stage1-target-libsanitizer
>         @[ $(current_stage) = stage1 ] || $(MAKE) stage1-start
>         @r=`${PWD_COMMAND}`; export r; \
>         s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
>         TFLAGS="$(STAGE1_TFLAGS)"; \
>         $(RAW_CXX_TARGET_EXPORTS)  \
>         cd $(TARGET_SUBDIR)/libsanitizer && \
>         $(MAKE) $(BASE_FLAGS_TO_PASS) \
>                 CFLAGS="$(CFLAGS_FOR_TARGET)" \
>                 CXXFLAGS="$(CXXFLAGS_FOR_TARGET)" \
>                 LIBCFLAGS="$(LIBCFLAGS_FOR_TARGET)" \
>                 CFLAGS_FOR_TARGET="$(CFLAGS_FOR_TARGET)" \
>                 CXXFLAGS_FOR_TARGET="$(CXXFLAGS_FOR_TARGET)" \
>                 LIBCFLAGS_FOR_TARGET="$(LIBCFLAGS_FOR_TARGET)" \
>                 $(EXTRA_TARGET_FLAGS) 'CXX=$$(RAW_CXX_FOR_TARGET)'
> 'CXX_FOR_TARGET=$$(RAW_CXX_FOR_TARGET)'  \
>                   \
>                 TFLAGS="$(STAGE1_TFLAGS)" \
>                 $(TARGET-stage1-target-libsanitizer)
> 
> The problem is
> 
> CXX=$$(RAW_CXX_FOR_TARGET)' 'CXX_FOR_TARGET=$$(RAW_CXX_FOR_TARGET)'
> 
> Those are bogus since
> 
> 1. We never set RAW_CXX_FOR_TARGET.
> 2. We have set
> 
>         CXX_FOR_TARGET="$(RAW_CXX_FOR_TARGET)"; export CXX_FOR_TARGET; \
>         CXX="$(RAW_CXX_FOR_TARGET) $(XGCC_FLAGS_FOR_TARGET) $$TFLAGS";
> export CXX;
> 
> in RAW_CXX_TARGET_EXPORTS.  There is no need to do anything.

Nope, if you remove this you get the wrong definition of CC and CXX from
EXTRA_TARGET_FLAGS.  Instead, you need to add RAW_CXX_FOR_TARGET to
AM_MAKEFLAGS and EXTRA_TARGET_FLAGS.

Paolo

> As the result, we get empty CXX and CXX_FOR_TARGET for multilib
> libsanitizer build.  That is why removing CC/CXX from AM_MAKEFLAGS
> was needed.  I am testing this patch.  But we don't want to pass
> CC/CXX to multilib build since:
> 
> [hjl@gnu-mic-2 x86_64-unknown-linux-gnu]$ grep "^CXX ="
> libsanitizer/Makefile 32/libsanitizer/Makefile
> libsanitizer/Makefile:CXX =
> /export/build/gnu/gcc-asan/build-x86_64-linux/./gcc/xgcc
> -shared-libgcc -B/export/build/gnu/gcc-asan/build-x86_64-linux/./gcc
> -nostdinc++ -L/export/build/gnu/gcc-asan/build-x86_64-linux/x86_64-unknown-linux-gnu/libstdc++-v3/src
> -L/export/build/gnu/gcc-asan/build-x86_64-linux/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
> -B/usr/local/x86_64-unknown-linux-gnu/bin/
> -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem
> /usr/local/x86_64-unknown-linux-gnu/include -isystem
> /usr/local/x86_64-unknown-linux-gnu/sys-include
> 32/libsanitizer/Makefile:CXX =
> /export/build/gnu/gcc-asan/build-x86_64-linux/./gcc/xgcc
> -shared-libgcc -B/export/build/gnu/gcc-asan/build-x86_64-linux/./gcc
> -nostdinc++ -L/export/build/gnu/gcc-asan/build-x86_64-linux/x86_64-unknown-linux-gnu/32/libstdc++-v3/src
> -L/export/build/gnu/gcc-asan/build-x86_64-linux/x86_64-unknown-linux-gnu/32/libstdc++-v3/src/.libs
> -B/usr/local/x86_64-unknown-linux-gnu/bin/
> -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem
> /usr/local/x86_64-unknown-linux-gnu/include -isystem
> /usr/local/x86_64-unknown-linux-gnu/sys-include  -m32
> [hjl@gnu-mic-2 x86_64-unknown-linux-gnu]$
> 
> As you can see, CXX are different for multilib.  If we CXX down:
> 
> all-multi:
>         $(MULTIDO) $(AM_MAKEFLAGS) DO=all multi-do # $(MAKE)
> 
> we may get the wrong CXX for multilib.
> 
> This patch fixes multilib build.  But we may still want to keep
> AM_MAKEFLAGS for "make CFLAGS=-g".
> 
>