libffi-3.1 on iOS

libffi-3.1 on iOS

[Ed VanVliet]

Dear libffi crew,

Bug report:

I just tried libffi-3.1 and it produced the issues below.

Can the warnings be eliminated and the link error fixed?

Sincerely,

Ed

---------------------------

Running libffi on iOS (iPhone) simulator works for both 32 and 64 bit simulators using libffi-3.0.14-rc0

But, with libffi-3.1 it works for 64 bit simulator, but fails to link for 32 bit simulator; giving the following:

(null): "_ffi_call_win32", referenced from:
(null): "_ffi_closure_FASTCALL", referenced from:
(null): "_ffi_closure_STDCALL", referenced from:
(null): "_ffi_closure_THISCALL", referenced from:
(null): Linker command failed with exit code 1 (use -v to see invocation)

Also, on both the 32 and 64 bit segments the linker gives this warning:

(null): Could not create compact unwind for .LFB3: non-standard register 5 being saved in prolog

which it gave for both 3.0.14-rc0 and 3.1. However, the warning does not seem to cause a problem.

On the ARM target the linker gives the following warnings:

ld: warning: arm64 function not 4-byte aligned: ltmp0 from /libffi.a(sysv_arm64.o)
ld: warning: arm64 function not 4-byte aligned: _ffi_call_SYSV from /libffi.a(sysv_arm64.o)
ld: warning: arm64 function not 4-byte aligned: _ffi_closure_SYSV from /libffi.a(sysv_arm64.o)

which also do not seem to cause a problem.

It would be nice to fix the build and code so it didn't produce the error and warnings.

Re: libffi-3.1 on iOS

[Anthony Green]

Ed VanVliet <ed@vvi.com> writes:

> Running libffi on iOS (iPhone) simulator works for both 32 and 64 bit simulators using libffi-3.0.14-rc0
>
> But, with libffi-3.1 it works for 64 bit simulator, but fails to link for 32 bit simulator; giving the following:
>
> (null): "_ffi_call_win32", referenced from:
> (null): "_ffi_closure_FASTCALL", referenced from:
> (null): "_ffi_closure_STDCALL", referenced from:
> (null): "_ffi_closure_THISCALL", referenced from:
> (null): Linker command failed with exit code 1 (use -v to see
> invocation)

Could you please try adding win32.S to src_files for
simulator64_platform in generate-darwin-source-and-headers.py and
rebuilding?


> Also, on both the 32 and 64 bit segments the linker gives this warning:
>
> (null): Could not create compact unwind for .LFB3: non-standard register 5 being saved in prolog
>
> which it gave for both 3.0.14-rc0 and 3.1. However, the warning does
> not seem to cause a problem.

Not sure about this yet.


> On the ARM target the linker gives the following warnings:
>
> ld: warning: arm64 function not 4-byte aligned: ltmp0 from /libffi.a(sysv_arm64.o)
> ld: warning: arm64 function not 4-byte aligned: _ffi_call_SYSV from /libffi.a(sysv_arm64.o)
> ld: warning: arm64 function not 4-byte aligned: _ffi_closure_SYSV from /libffi.a(sysv_arm64.o)
>
> which also do not seem to cause a problem.
>
> It would be nice to fix the build and code so it didn't produce the
> error and warnings.

So this is weird.  ffi_call_SYSV and ffi_closure_SYSV both have...

#ifdef __APPLE__
        .align 2
#endif

...which I believe should make things 4-byte aligned.  Is __APPLE__ not defined?

AG

Re: libffi-3.1 on iOS

[Ed VanVliet]

Dear AG,

On Jun 12, 2014, at 6:56 AM, Anthony Green <green@moxielogic.com> wrote:

> Ed VanVliet <ed@vvi.com> writes:
> 
>> Running libffi on iOS (iPhone) simulator works for both 32 and 64 bit simulators using libffi-3.0.14-rc0
>> 
>> But, with libffi-3.1 it works for 64 bit simulator, but fails to link for 32 bit simulator; giving the following:
>> 
>> (null): "_ffi_call_win32", referenced from:
>> (null): "_ffi_closure_FASTCALL", referenced from:
>> (null): "_ffi_closure_STDCALL", referenced from:
>> (null): "_ffi_closure_THISCALL", referenced from:
>> (null): Linker command failed with exit code 1 (use -v to see
>> invocation)
> 
> Could you please try adding win32.S to src_files for
> simulator64_platform in generate-darwin-source-and-headers.py and
> rebuilding?

The problem is in the 32 bit simulator, not the 64 bit simulator; and only when the .a archived is linked into a (nonrelocatable) application binary. Putting that into simulator64_platform makes no difference (it works both ways). Taking it out of simulator_platform does not solve the problem.


>> On the ARM target the linker gives the following warnings:
>> 
>> ld: warning: arm64 function not 4-byte aligned: ltmp0 from /libffi.a(sysv_arm64.o)
>> ld: warning: arm64 function not 4-byte aligned: _ffi_call_SYSV from /libffi.a(sysv_arm64.o)
>> ld: warning: arm64 function not 4-byte aligned: _ffi_closure_SYSV from /libffi.a(sysv_arm64.o)
>> 
>> which also do not seem to cause a problem.
>> 
>> It would be nice to fix the build and code so it didn't produce the
>> error and warnings.
> 
> So this is weird.  ffi_call_SYSV and ffi_closure_SYSV both have...
> 
> #ifdef __APPLE__
>        .align 2
> #endif
> 
> ...which I believe should make things 4-byte aligned.  Is __APPLE__ not defined?


__APPLE__ is defined during compilation of sysv_arm64.S

Sincerely,

Ed