Re: libffi merge

[Dave Korn <dave dot korn dot cygwin at googlemail dot com>]

Andrew Haley wrote:
> Timothy Wall wrote:
>>> @@ -311,13 +315,26 @@
>>> ({ unsigned char *__tramp = (unsigned char*)(TRAMP); \
>>>    unsigned int  __fun = (unsigned int)(FUN); \
>>>    unsigned int  __ctx = (unsigned int)(CTX); \
>>> -   unsigned int  __dis = __fun - (__ctx + FFI_TRAMPOLINE_SIZE); \
>>> +   unsigned int  __dis = __fun - (__ctx + 10);    \
>>>    *(unsigned char*) &__tramp[0] = 0xb8; \
>>>    *(unsigned int*)  &__tramp[1] = __ctx; /* movl __ctx, %eax */ \
>>>    *(unsigned char *)  &__tramp[5] = 0xe9; \
>>>    *(unsigned int*)  &__tramp[6] = __dis; /* jmp __fun  */ \
>>>  })
>>>
>> The above change looks like it was missed in the gcc patch.  While
>> FFI_TRAMPOLINE_SIZE is "10", the offset added to __ctx is an instruction
>> displacement, NOT the size of the trampoline.
> 
> Yes, I understand that the offset should be 10, not FFI_TRAMPOLINE_SIZE.
> I'm going to make sure that gcc's libffi has that change.  But until I
> can get a reply from Dave that explains what's going on I'm not going to
> touch anything.

  All my comments apply only to src/x86/win32.S; this patch (and any others to
any files other than win32.S) need merging to gcc.

    cheers,
      DaveK