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Fix ABI on 32-bit non-Windows x86: go back to trampoline size 10

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The trampoline size is part of the ABI, so it cannot change.  Move the
logic from the stdcall and thiscall trampolines to the functions they
call, to reduce them both to 10 bytes.

This drops the previously added support for raw THISCALL closures on
non-Windows.  (Non-raw THISCALL closures still work.)
This commit is contained in:
Josh Triplett
2014-04-05 17:33:42 -07:00
parent c860a992fe
commit b5fed60194
3 changed files with 67 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
src/x86/ffi.c
View File

@@ -439,9 +439,11 @@ unsigned int FFI_HIDDEN ffi_closure_SYSV_inner (ffi_closure *, void **, void *)
__attribute__ ((regparm(1)));
void FFI_HIDDEN ffi_closure_raw_SYSV (ffi_raw_closure *)
__attribute__ ((regparm(1)));
#ifndef X86_WIN64
#ifdef X86_WIN32
void FFI_HIDDEN ffi_closure_raw_THISCALL (ffi_raw_closure *)
__attribute__ ((regparm(1)));
#endif
#ifndef X86_WIN64
void FFI_HIDDEN ffi_closure_STDCALL (ffi_closure *)
__attribute__ ((regparm(1)));
void FFI_HIDDEN ffi_closure_THISCALL (ffi_closure *)
@@ -605,7 +607,7 @@ ffi_prep_incoming_args_SYSV(char *stack, void **rvalue, void **avalue,
*(unsigned int*) &__tramp[6] = __dis; /* jmp __fun */ \
}
#define FFI_INIT_TRAMPOLINE_THISCALL(TRAMP,FUN,CTX,SIZE) \
#define FFI_INIT_TRAMPOLINE_RAW_THISCALL(TRAMP,FUN,CTX,SIZE) \
{ unsigned char *__tramp = (unsigned char*)(TRAMP); \
unsigned int __fun = (unsigned int)(FUN); \
unsigned int __ctx = (unsigned int)(CTX); \
@@ -632,18 +634,15 @@ ffi_prep_incoming_args_SYSV(char *stack, void **rvalue, void **avalue,
*(unsigned short*) &__tramp[50] = (__size + 8); /* ret (__size + 8) */ \
}
#define FFI_INIT_TRAMPOLINE_STDCALL(TRAMP,FUN,CTX,SIZE) \
#define FFI_INIT_TRAMPOLINE_STDCALL(TRAMP,FUN,CTX) \
{ unsigned char *__tramp = (unsigned char*)(TRAMP); \
unsigned int __fun = (unsigned int)(FUN); \
unsigned int __ctx = (unsigned int)(CTX); \
unsigned int __dis = __fun - (__ctx + 10); \
unsigned short __size = (unsigned short)(SIZE); \
*(unsigned char*) &__tramp[0] = 0xb8; \
*(unsigned int*) &__tramp[1] = __ctx; /* movl __ctx, %eax */ \
*(unsigned char *) &__tramp[5] = 0xe8; \
*(unsigned int*) &__tramp[6] = __dis; /* call __fun */ \
*(unsigned char *) &__tramp[10] = 0xc2; \
*(unsigned short*) &__tramp[11] = __size; /* ret __size */ \
}
/* the cif must already be prep'ed */
@@ -675,16 +674,15 @@ ffi_prep_closure_loc (ffi_closure* closure,
}
else if (cif->abi == FFI_THISCALL)
{
FFI_INIT_TRAMPOLINE_THISCALL (&closure->tramp[0],
&ffi_closure_THISCALL,
(void*)codeloc,
cif->bytes);
FFI_INIT_TRAMPOLINE_STDCALL (&closure->tramp[0],
&ffi_closure_THISCALL,
(void*)codeloc);
}
else if (cif->abi == FFI_STDCALL)
{
FFI_INIT_TRAMPOLINE_STDCALL (&closure->tramp[0],
&ffi_closure_STDCALL,
(void*)codeloc, cif->bytes);
(void*)codeloc);
}
#ifdef X86_WIN32
else if (cif->abi == FFI_MS_CDECL)
@@ -721,7 +719,7 @@ ffi_prep_raw_closure_loc (ffi_raw_closure* closure,
int i;
if (cif->abi != FFI_SYSV
#ifndef X86_WIN64
#ifdef X86_WIN32
&& cif->abi != FFI_THISCALL
#endif
)
@@ -738,18 +736,17 @@ ffi_prep_raw_closure_loc (ffi_raw_closure* closure,
FFI_ASSERT (cif->arg_types[i]->type != FFI_TYPE_LONGDOUBLE);
}
#ifndef X86_WIN64
#ifdef X86_WIN32
if (cif->abi == FFI_SYSV)
{
#endif
FFI_INIT_TRAMPOLINE (&closure->tramp[0], &ffi_closure_raw_SYSV,
codeloc);
#ifndef X86_WIN64
#ifdef X86_WIN32
}
else if (cif->abi == FFI_THISCALL)
{
FFI_INIT_TRAMPOLINE_THISCALL (&closure->tramp[0], &ffi_closure_raw_THISCALL,
codeloc, cif->bytes);
FFI_INIT_TRAMPOLINE_RAW_THISCALL (&closure->tramp[0], &ffi_closure_raw_THISCALL, codeloc);
}
#endif
closure->cif = cif;