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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;

12
src/x86/ffitarget.h
View File

@@ -122,14 +122,22 @@ typedef enum ffi_abi {
#if defined (X86_64) || (defined (__x86_64__) && defined (X86_DARWIN))
#define FFI_TRAMPOLINE_SIZE 24
#define FFI_NATIVE_RAW_API 0
#elif defined(X86_WIN64)
#else
#ifdef X86_WIN32
#define FFI_TRAMPOLINE_SIZE 52
#else
#ifdef X86_WIN64
#define FFI_TRAMPOLINE_SIZE 29
#define FFI_NATIVE_RAW_API 0
#define FFI_NO_RAW_API 1
#else
#define FFI_TRAMPOLINE_SIZE 52
#define FFI_TRAMPOLINE_SIZE 10
#endif
#endif
#ifndef X86_WIN64
#define FFI_NATIVE_RAW_API 1 /* x86 has native raw api support */
#endif
#endif
#endif

61
src/x86/win32.S
View File

@@ -33,8 +33,13 @@
#include <fficonfig.h>
#include <ffi.h>
#define CIF_ABI_OFFSET 0
#define CIF_BYTES_OFFSET 16
#ifdef _MSC_VER
#define CLOSURE_CIF_OFFSET ((FFI_TRAMPOLINE_SIZE + 3) AND NOT 3)
.386
.MODEL FLAT, C
@@ -188,12 +193,12 @@ ca_epilogue:
ret
ffi_call_win32 ENDP
ffi_closure_THISCALL PROC NEAR FORCEFRAME
sub esp, 40
lea edx, [ebp -24]
mov [ebp - 12], edx /* resp */
lea edx, [ebp + 12] /* account for stub return address on stack */
jmp stub
ffi_closure_THISCALL PROC NEAR
;; Insert the register argument on the stack as the first argument
xchg DWORD PTR [esp+4], ecx
xchg DWORD PTR [esp], ecx
push ecx
jmp ffi_closure_STDCALL
ffi_closure_THISCALL ENDP
ffi_closure_SYSV PROC NEAR FORCEFRAME
@@ -464,8 +469,18 @@ cd_retlongdouble:
jmp cd_epilogue
cd_epilogue:
;; Epilogue code is autogenerated.
ret
mov esp, ebp
pop ebp
pop ecx
mov ecx, DWORD PTR [ecx + (CLOSURE_CIF_OFFSET-10)]
cmp DWORD PTR [ecx + CIF_ABI_OFFSET], 3
mov ecx, DWORD PTR [ecx + CIF_BYTES_OFFSET]
jne cd_not_thiscall
add ecx, 4
cd_not_thiscall:
pop edx
add esp, ecx
jmp edx
ffi_closure_STDCALL ENDP
_TEXT ENDS
@@ -473,6 +488,8 @@ END
#else
#define CLOSURE_CIF_OFFSET ((FFI_TRAMPOLINE_SIZE + 3) & ~3)
#if defined(SYMBOL_UNDERSCORE)
#define USCORE_SYMBOL(x) _##x
#else
@@ -657,13 +674,11 @@ FFI_HIDDEN(ffi_closure_THISCALL)
.def _ffi_closure_THISCALL; .scl 2; .type 32; .endef
#endif
USCORE_SYMBOL(ffi_closure_THISCALL):
pushl %ebp
movl %esp, %ebp
subl $40, %esp
leal -24(%ebp), %edx
movl %edx, -12(%ebp) /* resp */
leal 12(%ebp), %edx /* account for stub return address on stack */
jmp .stub
/* Insert the register argument on the stack as the first argument */
xchg %ecx, 4(%esp)
xchg %ecx, (%esp)
push %ecx
jmp .ffi_closure_STDCALL_internal
.LFE1:
# This assumes we are using gas.
@@ -685,7 +700,6 @@ USCORE_SYMBOL(ffi_closure_SYSV):
leal -24(%ebp), %edx
movl %edx, -12(%ebp) /* resp */
leal 8(%ebp), %edx
.stub:
movl %edx, 4(%esp) /* args = __builtin_dwarf_cfa () */
leal -12(%ebp), %edx
movl %edx, (%esp) /* &resp */
@@ -811,6 +825,8 @@ USCORE_SYMBOL(ffi_closure_SYSV):
#define RAW_CLOSURE_FUN_OFFSET (RAW_CLOSURE_CIF_OFFSET + 4)
#define RAW_CLOSURE_USER_DATA_OFFSET (RAW_CLOSURE_FUN_OFFSET + 4)
#define CIF_FLAGS_OFFSET 20
#ifdef X86_WIN32
.balign 16
FFI_HIDDEN(ffi_closure_raw_THISCALL)
.globl USCORE_SYMBOL(ffi_closure_raw_THISCALL)
@@ -827,6 +843,8 @@ USCORE_SYMBOL(ffi_closure_raw_THISCALL):
movl %edx, 12(%esp) /* user_data */
leal 12(%ebp), %edx /* __builtin_dwarf_cfa () */
jmp .stubraw
#endif /* X86_WIN32 */
# This assumes we are using gas.
.balign 16
#if defined(X86_WIN32)
@@ -958,6 +976,7 @@ FFI_HIDDEN(ffi_closure_STDCALL)
.def _ffi_closure_STDCALL; .scl 2; .type 32; .endef
#endif
USCORE_SYMBOL(ffi_closure_STDCALL):
.ffi_closure_STDCALL_internal:
.LFB5:
pushl %ebp
.LCFI9:
@@ -1070,7 +1089,15 @@ USCORE_SYMBOL(ffi_closure_STDCALL):
.Lscls_epilogue:
movl %ebp, %esp
popl %ebp
ret
popl %ecx
movl (CLOSURE_CIF_OFFSET-10)(%ecx), %ecx
cmpl $3, CIF_ABI_OFFSET(%ecx) /* FFI_THISCALL */
movl CIF_BYTES_OFFSET(%ecx), %ecx
jne 1f
addl $4, %ecx
1: popl %edx
addl %ecx, %esp
jmp *%edx
.ffi_closure_STDCALL_end:
.LFE5: