[cfe-dev] i386 -faddress-sanitizer

[Carsten Mattner]

On Thu, Oct 18, 2012 at 4:49 PM, Kostya Serebryany <kcc at google.com> wrote:
> You are linking a shared object, asan.a should not be linked to it.

What should happen instead?

> Are these all the flags passed to ld?

Yes it's all minus project-specific -l and *.a and *.o args
I have omitted for the email.

> On Thu, Oct 18, 2012 at 6:23 PM, Carsten Mattner <carstenmattner at gmail.com>
> wrote:
>>
>> On Thu, Oct 18, 2012 at 3:36 PM, Alexander Potapenko <glider at google.com>
>> wrote:
>> > Can you append -v at the place it's being invoked to check whether the
>> > contents of LDFLAGS are being actually passed?
>>
>> $ clang <INPUT_OBJECTS> -lstdc++ -v -faddress-sanitizer -shared
>> <PROJECT_FLAGS> -o <SO_FILE>
>> clang
>> version 3.2 (http://llvm.org/git/clang.git
>> 278eafa2cd8296f8128d13c6466a0ace3d03a872)
>> (http://llvm.org/git/llvm.git
>> 2360b7ad99eedecaae512373e7be49c2143550cf)
>> Target: i386-pc-linux-gnu
>> Thread model: posix
>>
>> "/usr/bin/ld" --eh-frame-hdr -m elf_i386 -shared -o <SO_FILE>
>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../../crti.o
>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/crtbeginS.o
>> -L/usr/lib/gcc/i686-pc-linux-gnu/4.7.2
>> -L/usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../.. -L/lib -L/usr/lib
>> <INPUT_OBJECTS> -lstdc++ -lgcc --as-needed -lgcc_s --no-as-needed -lc
>> -lgcc --as-needed -lgcc_s --no-as-needed
>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/crtendS.o
>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../../crtn.o
>>
>> I guess the libasan archive should be part of the above call to ld.
>>
>> > On Thu, Oct 18, 2012 at 5:33 PM, Carsten Mattner
>> > <carstenmattner at gmail.com> wrote:
>> >> On Thu, Oct 18, 2012 at 3:29 PM, Alexander Potapenko wrote:
>> >>> Are you linking with ld or clang?
>> >>> -faddress-sanitizer is a Clang flag, so if you're running `ld $LDFLAGS
>> >>> ...` to link your program, it won't work.
>> >>
>> >> clang.
>> >>
>> >>> On Thu, Oct 18, 2012 at 5:12 PM, Carsten Mattner
>> >>> <carstenmattner at gmail.com> wrote:
>> >>>> On Thu, Oct 18, 2012 at 12:27 AM, Eli Friedman wrote:
>> >>>>> On Wed, Oct 17, 2012 at 1:43 PM, Carsten Mattner
>> >>>>> <carstenmattner at gmail.com> wrote:
>> >>>>>> Is it expected that -faddress-sanitizer  does not work on i386 and
>> >>>>>> fails
>> >>>>>> to properly link resulting in errors like 'undefined symbol:
>> >>>>>> __asan_init'
>> >>>>>> at runtime?
>> >>>>>>
>> >>>>>> I have ./lib/clang/3.2/lib/linux/libclang_rt.asan-i386.a in llvm's
>> >>>>>> installation,
>> >>>>>> but it doesn't look like it's linked automatically into the
>> >>>>>> executable.
>> >>>>>>
>> >>>>>> CFLAGS:
>> >>>>>> -faddress-sanitizer -O1 -fno-omit-frame-pointer -g $PROJECT_FLAGS
>> >>>>>
>> >>>>> You need to pass in -faddress-sanitizer both when compiling and when
>> >>>>> linking an application.  Try something like
>> >>>>> "LDFLAGS=-faddress-sanitizer".
>> >>>>
>> >>>> Oh that makes a lot of sense and is kind of obvious in hindsight.
>> >>>> Yet it didn't work in a quick test. Any options I flags to pass for
>> >>>> verbose printfs to see what's happening you can suggest?
>> >>>> In the next test I'll also try to explicitly link the libasan archive
>> >>>> manually for ruling out issues with that archive.
>> >>>> _______________________________________________
>> >>>> cfe-dev mailing list
>> >>>> cfe-dev at cs.uiuc.edu
>> >>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Alexander Potapenko
>> >>> Software Engineer
>> >>> Google Moscow
>> >
>> >
>> >
>> > --
>> > Alexander Potapenko
>> > Software Engineer
>> > Google Moscow
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
>