1 /* ----------------------------------------------------------------------- 2 win32.S - Copyright (c) 1996, 1998, 2001, 2002 Red Hat, Inc. 3 Copyright (c) 2001 John Beniton 4 Copyright (c) 2002 Ranjit Mathew 5 6 7 X86 Foreign Function Interface 8 9 Permission is hereby granted, free of charge, to any person obtaining 10 a copy of this software and associated documentation files (the 11 ``Software''), to deal in the Software without restriction, including 12 without limitation the rights to use, copy, modify, merge, publish, 13 distribute, sublicense, and/or sell copies of the Software, and to 14 permit persons to whom the Software is furnished to do so, subject to 15 the following conditions: 16 17 The above copyright notice and this permission notice shall be included 18 in all copies or substantial portions of the Software. 19 20 THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS 21 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 22 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 23 IN NO EVENT SHALL CYGNUS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR 24 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 25 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 OTHER DEALINGS IN THE SOFTWARE. 27 ----------------------------------------------------------------------- */ 28 29 /* theller: almost verbatim translation from gas syntax to MSVC inline 30 assembler code. */ 31 32 /* theller: ffi_call_x86 now returns an integer - the difference of the stack 33 pointer before and after the function call. If everything is ok, zero is 34 returned. If stdcall functions are passed the wrong number of arguments, 35 the difference will be nonzero. */ 36 37 #include <ffi.h> 38 #include <ffi_common.h> 39 40 __declspec(naked) int 41 ffi_call_x86(void (* prepfunc)(char *, extended_cif *), /* 8 */ 42 extended_cif *ecif, /* 12 */ 43 unsigned bytes, /* 16 */ 44 unsigned flags, /* 20 */ 45 unsigned *rvalue, /* 24 */ 46 void (*fn)()) /* 28 */ 47 { 48 _asm { 49 push ebp 50 mov ebp, esp 51 52 push esi // NEW: this register must be preserved across function calls 53 // XXX SAVE ESP NOW! 54 mov esi, esp // save stack pointer before the call 55 56 // Make room for all of the new args. 57 mov ecx, [ebp+16] 58 sub esp, ecx // sub esp, bytes 59 60 mov eax, esp 61 62 // Place all of the ffi_prep_args in position 63 push [ebp + 12] // ecif 64 push eax 65 call [ebp + 8] // prepfunc 66 67 // Return stack to previous state and call the function 68 add esp, 8 69 // FIXME: Align the stack to a 128-bit boundary to avoid 70 // potential performance hits. 71 call [ebp + 28] 72 73 // Load ecif->cif->abi 74 mov ecx, [ebp + 12] 75 mov ecx, [ecx]ecif.cif 76 mov ecx, [ecx]ecif.cif.abi 77 78 cmp ecx, FFI_STDCALL 79 je noclean 80 // STDCALL: Remove the space we pushed for the args 81 mov ecx, [ebp + 16] 82 add esp, ecx 83 // CDECL: Caller has already cleaned the stack 84 noclean: 85 // Check that esp has the same value as before! 86 sub esi, esp 87 88 // Load %ecx with the return type code 89 mov ecx, [ebp + 20] 90 91 // If the return value pointer is NULL, assume no return value. 92 /* 93 Intel asm is weird. We have to explicitely specify 'DWORD PTR' in the nexr instruction, 94 otherwise only one BYTE will be compared (instead of a DWORD)! 95 */ 96 cmp DWORD PTR [ebp + 24], 0 97 jne sc_retint 98 99 // Even if there is no space for the return value, we are 100 // obliged to handle floating-point values. 101 cmp ecx, FFI_TYPE_FLOAT 102 jne sc_noretval 103 // fstp %st(0) 104 fstp st(0) 105 106 jmp sc_epilogue 107 108 sc_retint: 109 cmp ecx, FFI_TYPE_INT 110 jne sc_retfloat 111 // # Load %ecx with the pointer to storage for the return value 112 mov ecx, [ebp + 24] 113 mov [ecx + 0], eax 114 jmp sc_epilogue 115 116 sc_retfloat: 117 cmp ecx, FFI_TYPE_FLOAT 118 jne sc_retdouble 119 // Load %ecx with the pointer to storage for the return value 120 mov ecx, [ebp+24] 121 // fstps (%ecx) 122 fstp DWORD PTR [ecx] 123 jmp sc_epilogue 124 125 sc_retdouble: 126 cmp ecx, FFI_TYPE_DOUBLE 127 jne sc_retlongdouble 128 // movl 24(%ebp),%ecx 129 mov ecx, [ebp+24] 130 fstp QWORD PTR [ecx] 131 jmp sc_epilogue 132 133 jmp sc_retlongdouble // avoid warning about unused label 134 sc_retlongdouble: 135 cmp ecx, FFI_TYPE_LONGDOUBLE 136 jne sc_retint64 137 // Load %ecx with the pointer to storage for the return value 138 mov ecx, [ebp+24] 139 // fstpt (%ecx) 140 fstp QWORD PTR [ecx] /* XXX ??? */ 141 jmp sc_epilogue 142 143 sc_retint64: 144 cmp ecx, FFI_TYPE_SINT64 145 jne sc_retstruct 146 // Load %ecx with the pointer to storage for the return value 147 mov ecx, [ebp+24] 148 mov [ecx+0], eax 149 mov [ecx+4], edx 150 151 sc_retstruct: 152 // Nothing to do! 153 154 sc_noretval: 155 sc_epilogue: 156 mov eax, esi 157 pop esi // NEW restore: must be preserved across function calls 158 mov esp, ebp 159 pop ebp 160 ret 161 } 162 } 163
