[Bug d/103577] d21 SIGSEGV on Darwin/x86_64

["ro at CeBiTec dot Uni-Bielefeld.DE" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103577

--- Comment #1 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> I recently tried to build master on Darwin 11 with gcc 11.0.1.  That's the
> first
> release to build gdc, and while libphobos isn't marked as supported in
> libphobos/configure.tgt, it does build with --enable-libphobos.
>
> However, with that gdc as bootstrap compiler, the resulting d21 SEGVs building
> the stage1 libphobos, e.g.

FWIW, I recently tried the same procedure in a macOS 12.1 VM
(x86_64-apple-darwin21.2.0).  This time, the build succeeded and test
results are reasonable

                === gdc Summary ===

# of expected passes            11587
# of unsupported tests          2

                === libphobos Summary ===

# of expected passes            556
# of unexpected failures        7
# of unsupported tests          1

although I had to rerun the libphobos tests sequentially since several
would time out otherwise.

There's one caveat, though, that applies equally to Mac OS X 10.7 and
macOS 12.1: at least some of the stage1 dependency lists in gcc/d/.deps
are corrupt in that they contain D source code after the dependencies
proper, e.g. gcc/d/.deps/hash.Po:

d/root-hash.o: /vol/gcc/src/hg/master/darwin/gcc/d/dmd/root/hash.d
is.value == c.value;
    }

    override size_t getHash(scope const void* p) @trusted const
    {
        return getArrayHash(value, p, len);
    }
[...]

I cannot yet tell if this is just an issue with GCC 11.1.0 gdc or
libphobos that's fixed in 11.2.0 or gcc-11 branch.