On 29 Jun 2017, at 21:41, Simon Wright <si...@pushface.org> wrote:
>
> On 28 Jun 2017, at 18:40, Jeff Law <l...@redhat.com> wrote:
>>
>> On 06/09/2017 07:57 AM, Simon Wright wrote:
>>> 2017-06-09 Simon Wright <si...@pushface.org>
>>>
>>> PR target/80556
>>> * configure.ac (stage1_ldflags): For Darwin, include -lSystem.
>>> (poststage1_ldflags): likewise.
>>> * configure: regenerated.
>> I'm a bit confused here. Isn't -lSystem included in darwin's LIB_SPEC
>> in which case the right things ought to already be happening, shouldn't it?
>
> The specs that involve -lSystem are
>
> *link_gcc_c_sequence:
> %:version-compare(>= 10.6 mmacosx-version-min= -no_compact_unwind)
> %{!static:%{!static-libgcc: %:version-compare(>= 10.6
> mmacosx-version-min= -lSystem) } }
> %{fno-pic|fno-PIC|fno-pie|fno-PIE|fapple-kext|mkernel|static|mdynamic-no-pic:
> %:version-compare(>= 10.7 mmacosx-version-min= -no_pie) } %G %L
>
> *lib:
> %{!static:-lSystem}
>
> but I also see
>
> *libgcc:
> %{static-libgcc|static: -lgcc_eh -lgcc; ....
>
> which might be the root of the problem?
>
> Looking at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80556#c39, I report
> that
>
> $ gnatmake raiser -largs -static-libgcc -static-libstdc++
>
> resulted in the link command
>
> /usr/bin/ld -dynamic -arch x86_64 -macosx_version_min 10.12.0
> -weak_reference_mismatches non-weak -o raiser -L./
> -L/opt/gcc-7.1.0/lib/gcc/x86_64-apple-darwin15/7.1.0/adalib/
> -L/opt/gcc-7.1.0/lib/gcc/x86_64-apple-darwin15/7.1.0
> -L/opt/gcc-7.1.0/lib/gcc/x86_64-apple-darwin15/7.1.0/../../.. b~raiser.o
> ./raiser.o -v
> /opt/gcc-7.1.0/lib/gcc/x86_64-apple-darwin15/7.1.0/adalib/libgnat.a
> -no_compact_unwind -lgcc_eh -lgcc -lSystem
>
> i.e. -lSystem is *after* -lgcc, so that its exception handling won't be
> invoked.
>
> I don't know what -lgcc_eh does, but my patch would be pretty much equivalent
> to changing the libgcc spec above to
>
> *libgcc:
> %{static-libgcc|static: -lSystem -lgcc_eh -lgcc; ....
>
> and if that would be OK it would obviously be much better.
>
> I've rebuilt gcc-8-20170528 with this change alone (i.e. not the patch
> currently posted here), successfully.
I've rebuilt and tested gcc-8-20170820 with this change, successfully.
gcc/Changelog:
2017-09-01 Simon Wright <si...@pushface.org>
PR target/80556
* config/darwin.h (REAL_LIBGCC_SPEC): for static-libgcc|static, include
-lSystem first.
80556-darwin.h.diff
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