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Re: r196201 - in /trunk: gcc/ChangeLog gcc/config/i...
On Fri, Feb 22, 2013 at 4:58 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Fri, Feb 22, 2013 at 11:53:39AM +0400, Konstantin Serebryany wrote:
>> Jakub, thanks again for cleaning up my mess.
>>
>> Here is a question regarding your fix:
>> > -#if ASAN_USE_PREINIT_ARRAY
>> > +#if ASAN_USE_PREINIT_ARRAY && !defined (PIC)
>>
>> The PIC macro is an artifact of the GCC build system and is not
>> directly related the the -fPIC flag?
>> As I can see, in the gcc build we compile all of asan sources twice:
>> w/ and w/o "-fPIC -DPIC".
>> If I move the preinit_array to a separate file (asan_preinit.cc), will
>> we need to have two builds?
>> I think we can just build all objects once with -fPIC and then not
>> link asan_preinit.o into libasan.so
>> In clang we build the static libasan with -fPIC, it doesn't hurt.
>> Anyway, I've just committed
>> http://llvm.org/viewvc/llvm-project?rev=175871&view=rev with
>> asan_preinit.cc
>
> Here is corresponding gcc patch to use it.
> libasan_preinit.o is installed alongside with libasan.a and libasan.so*,
> and linked into executables (but not shared libraries).
>
> Additionally, I've added __attribute__((constructor)) to __asan_init,
> to make it more likely that asan will be initialized properly even when
> the executable isn't instrumented. Shared libraries linked with
> -fsanitize=address will depend on libasan.so.0, and the dynamic linker first
> runs constructors of dependencies before running constructors of the
> libraries that have those dependencies (unless there are dependency cycles, but that
> is a user bug).
>
> 2013-02-22 Jakub Jelinek <jakub@redhat.com>
>
> PR sanitizer/56393
> * config/gnu-user.h (LIBASAN_EARLY_SPEC): Link in libasan_preinit.o
> if not linking a shared library.
>
> * lib/asan-dg.exp (asan_link_flags): Add
> -B${gccpath}/libsanitizer/asan/ to flags.
>
> * asan/Makefile.am (nodist_toolexeclib_HEADERS): Set to
> libasan_preinit.o.
> (libasan_preinit.o): Depend on asan_preinit.o.
> * asan/Makefile.in: Regenerated.
> * asan/asan_preinit.cc: New file, synced from upstream.
> * asan/asan_rtl.cc: Remove preinit stuff, synced from upstream.
> Add __attribute__((constructor)) to __asan_init.
>
We also need this patch. OK to install?
Thanks.
H.J.
--
2013-02-22 H.J. Lu <hongjiu.lu@intel.com>
* bootstrap-asan.mk (POSTSTAGE1_LDFLAGS): Add
-B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/asan/.
diff --git a/config/bootstrap-asan.mk b/config/bootstrap-asan.mk
index d37a9da..e3f34f5 100644
--- a/config/bootstrap-asan.mk
+++ b/config/bootstrap-asan.mk
@@ -3,4 +3,5 @@
STAGE2_CFLAGS += -fsanitize=address
STAGE3_CFLAGS += -fsanitize=address
POSTSTAGE1_LDFLAGS += -fsanitize=address -static-libasan \
+ -B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/asan/ \
-B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/asan/.libs