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.
If I propose this alternative patch, should it be a new post, or should I
continue this thread?
