Re: [COMMITTED] Merge libffi with upstream

[Richard Henderson <rth at redhat dot com>]

On 01/15/2015 08:54 AM, H.J. Lu wrote:
> On Thu, Jan 15, 2015 at 8:40 AM, Rainer Orth
> <ro@cebitec.uni-bielefeld.de> wrote:
>> Richard Henderson <rth@redhat.com> writes:
>>
>>> Upstream libffi has added support for Go closures (using the static chain),
>>> and support for complex numbers.  Perhaps less relevant is new support for
>>> arc, microblaze, moxie, nios, and or1k targets.
>>>
>>> Without additional changes for Go, this merge has little effect.  Within the
>>> gcc tree libffi is primarily used by libjava.
>>>
>>> Tested with no regressions on {i686,x86_64,ppc64,s390x,aarch64,alpha}-linux.
>>>
>>> Due to upstream breakage, and difficulty debugging on Darwin,
>>> {i686,x86_64}-darwin retains copies of the existing sources and thus remains
>>> 100% unchanged.  Since libgo doesn't support darwin, this should cause no
>>> immediate problems.
>>
>> The patch introduced massive problems on Solaris, both SPARC and x86:
>>
>> * on Solaris/SPARC, /bin/as requires
>>
>>   .type fn,#function
>>
>>   instead of @function.  I've simply commented the affected lines in
>>   src/sparc/v[89].S to make progress.
>>
>> * /bin/as doesn't support .macro/.endm.  I'm using preprocessor macros
>>   instead to implement E in src/sparc/v[89].S and src/x86/{sysv,
>>   unix64}.S.
>>
>> * Solaris/x86 /bin/as doesn't support .org, so I've just disabled the
>>   uses in src/x86/{sysv, unix64}.S, as on Darwin.
>>
>> * Solaris/x86 /bin/as has different COMDAT syntax; I've disabled it for
>>   the moment.
>>
>> * Solaris/x86 needs to use EH_FRAME_FLAGS so manually and compiler
>>   generated .eh_frame sections match, otherwise libffi.so fails to link:
>>
>> ld: fatal: file src/.libs/prep_cif.o; section [16].eh_frame and file src/x86/.libs/sysv.o; section [9].eh_frame have incompatibile attributes and cannot be merged into a single output section
>>
>> * Yet unfixed for Solaris/SPARC /bin/as:
>>
>> as: "v8.s", line 128: error: invalid digit in radix 10
>>
>>   as seems to only understand single-digit labels
>>
>> as: "v8.s", line 140: error: statement syntax
>> as: "v8.s", line 157: error: unknown opcode ".rept"
>> as: "v8.s", line 157: error: statement syntax
>> as: "v8.s", line 163: error: unknown opcode ".endr"
>> as: "v8.s", line 163: error: statement syntax
>>
>>   and knows nothing about .rept/.endr
>>
>> Here are the hacks I've used to make some progress:
>>
> 
> I think we should
> 
> 1.  Revert the libffi merge patch.
> 2.  Create a GCC integration branch from the merge commit
> in libffi git repo

How's that going to help?  The build infrastructure is totally different.
That and the fact that extremely few people test upstream libffi.

> 4. Copy the the GCC integration branch to gcc/libffi,  NOT the
> unmodified libffi commit.

I beg your pardon?


r~