gomp-20050608-branch/libffi/src/x86/ffi.c

   1 /* -----------------------------------------------------------------------
   2    ffi.c - Copyright (c) 1996, 1998, 1999, 2001  Red Hat, Inc.
   3            Copyright (c) 2002  Ranjit Mathew
   4            Copyright (c) 2002  Bo Thorsen
   5            Copyright (c) 2002  Roger Sayle
   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 #ifndef __x86_64__
  30
  31 #include <ffi.h>
  32 #include <ffi_common.h>
  33
  34 #include <stdlib.h>
  35
  36 /* ffi_prep_args is called by the assembly routine once stack space
  37    has been allocated for the function's arguments */
  38
  39 /*@-exportheader@*/
  40 void ffi_prep_args(char *stack, extended_cif *ecif)
  41 /*@=exportheader@*/
  42 {
  43   register unsigned int i;
  44   register void **p_argv;
  45   register char *argp;
  46   register ffi_type **p_arg;
  47
  48   argp = stack;
  49
  50   if (ecif->cif->flags == FFI_TYPE_STRUCT)
  51     {
  52       *(void **) argp = ecif->rvalue;
  53       argp += 4;
  54     }
  55
  56   p_argv = ecif->avalue;
  57
  58   for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
  59        i != 0;
  60        i--, p_arg++)
  61     {
  62       size_t z;
  63
  64       /* Align if necessary */
  65       if ((sizeof(int) - 1) & (unsigned) argp)
  66         argp = (char *) ALIGN(argp, sizeof(int));
  67
  68       z = (*p_arg)->size;
  69       if (z < sizeof(int))
  70         {
  71           z = sizeof(int);
  72           switch ((*p_arg)->type)
  73             {
  74             case FFI_TYPE_SINT8:
  75               *(signed int *) argp = (signed int)*(SINT8 *)(* p_argv);
  76               break;
  77
  78             case FFI_TYPE_UINT8:
  79               *(unsigned int *) argp = (unsigned int)*(UINT8 *)(* p_argv);
  80               break;
  81
  82             case FFI_TYPE_SINT16:
  83               *(signed int *) argp = (signed int)*(SINT16 *)(* p_argv);
  84               break;
  85
  86             case FFI_TYPE_UINT16:
  87               *(unsigned int *) argp = (unsigned int)*(UINT16 *)(* p_argv);
  88               break;
  89
  90             case FFI_TYPE_SINT32:
  91               *(signed int *) argp = (signed int)*(SINT32 *)(* p_argv);
  92               break;
  93
  94             case FFI_TYPE_UINT32:
  95               *(unsigned int *) argp = (unsigned int)*(UINT32 *)(* p_argv);
  96               break;
  97
  98             case FFI_TYPE_STRUCT:
  99               *(unsigned int *) argp = (unsigned int)*(UINT32 *)(* p_argv);
 100               break;
 101
 102             default:
 103               FFI_ASSERT(0);
 104             }
 105         }
 106       else
 107         {
 108           memcpy(argp, *p_argv, z);
 109         }
 110       p_argv++;
 111       argp += z;
 112     }
 113
 114   return;
 115 }
 116
 117 /* Perform machine dependent cif processing */
 118 ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
 119 {
 120   /* Set the return type flag */
 121   switch (cif->rtype->type)
 122     {
 123     case FFI_TYPE_VOID:
 124 #ifndef X86_WIN32
 125     case FFI_TYPE_STRUCT:
 126 #endif
 127     case FFI_TYPE_SINT64:
 128     case FFI_TYPE_FLOAT:
 129     case FFI_TYPE_DOUBLE:
 130     case FFI_TYPE_LONGDOUBLE:
 131       cif->flags = (unsigned) cif->rtype->type;
 132       break;
 133
 134     case FFI_TYPE_UINT64:
 135       cif->flags = FFI_TYPE_SINT64;
 136       break;
 137
 138 #ifdef X86_WIN32
 139     case FFI_TYPE_STRUCT:
 140       if (cif->rtype->size == 1)
 141         {
 142           cif->flags = FFI_TYPE_SINT8; /* same as char size */
 143         }
 144       else if (cif->rtype->size == 2)
 145         {
 146           cif->flags = FFI_TYPE_SINT16; /* same as short size */
 147         }
 148       else if (cif->rtype->size == 4)
 149         {
 150           cif->flags = FFI_TYPE_INT; /* same as int type */
 151         }
 152       else if (cif->rtype->size == 8)
 153         {
 154           cif->flags = FFI_TYPE_SINT64; /* same as int64 type */
 155         }
 156       else
 157         {
 158           cif->flags = FFI_TYPE_STRUCT;
 159         }
 160       break;
 161 #endif
 162
 163     default:
 164       cif->flags = FFI_TYPE_INT;
 165       break;
 166     }
 167
 168   return FFI_OK;
 169 }
 170
 171 /*@-declundef@*/
 172 /*@-exportheader@*/
 173 extern void ffi_call_SYSV(void (*)(char *, extended_cif *),
 174                           /*@out@*/ extended_cif *,
 175                           unsigned, unsigned,
 176                           /*@out@*/ unsigned *,
 177                           void (*fn)());
 178 /*@=declundef@*/
 179 /*@=exportheader@*/
 180
 181 #ifdef X86_WIN32
 182 /*@-declundef@*/
 183 /*@-exportheader@*/
 184 extern void ffi_call_STDCALL(void (*)(char *, extended_cif *),
 185                           /*@out@*/ extended_cif *,
 186                           unsigned, unsigned,
 187                           /*@out@*/ unsigned *,
 188                           void (*fn)());
 189 /*@=declundef@*/
 190 /*@=exportheader@*/
 191 #endif /* X86_WIN32 */
 192
 193 void ffi_call(/*@dependent@*/ ffi_cif *cif,
 194               void (*fn)(),
 195               /*@out@*/ void *rvalue,
 196               /*@dependent@*/ void **avalue)
 197 {
 198   extended_cif ecif;
 199
 200   ecif.cif = cif;
 201   ecif.avalue = avalue;
 202
 203   /* If the return value is a struct and we don't have a return */
 204   /* value address then we need to make one                     */
 205
 206   if ((rvalue == NULL) &&
 207       (cif->flags == FFI_TYPE_STRUCT))
 208     {
 209       /*@-sysunrecog@*/
 210       ecif.rvalue = alloca(cif->rtype->size);
 211       /*@=sysunrecog@*/
 212     }
 213   else
 214     ecif.rvalue = rvalue;
 215
 216
 217   switch (cif->abi)
 218     {
 219     case FFI_SYSV:
 220       /*@-usedef@*/
 221       ffi_call_SYSV(ffi_prep_args, &ecif, cif->bytes,
 222                     cif->flags, ecif.rvalue, fn);
 223       /*@=usedef@*/
 224       break;
 225 #ifdef X86_WIN32
 226     case FFI_STDCALL:
 227       /*@-usedef@*/
 228       ffi_call_STDCALL(ffi_prep_args, &ecif, cif->bytes,
 229                     cif->flags, ecif.rvalue, fn);
 230       /*@=usedef@*/
 231       break;
 232 #endif /* X86_WIN32 */
 233     default:
 234       FFI_ASSERT(0);
 235       break;
 236     }
 237 }
 238
 239
 240 /** private members **/
 241
 242 static void ffi_prep_incoming_args_SYSV (char *stack, void **ret,
 243                                          void** args, ffi_cif* cif);
 244 void FFI_HIDDEN ffi_closure_SYSV (ffi_closure *)
 245      __attribute__ ((regparm(1)));
 246 unsigned int FFI_HIDDEN ffi_closure_SYSV_inner (ffi_closure *, void **, void *)
 247      __attribute__ ((regparm(1)));
 248 void FFI_HIDDEN ffi_closure_raw_SYSV (ffi_raw_closure *)
 249      __attribute__ ((regparm(1)));
 250
 251 /* This function is jumped to by the trampoline */
 252
 253 unsigned int FFI_HIDDEN
 254 ffi_closure_SYSV_inner (closure, respp, args)
 255      ffi_closure *closure;
 256      void **respp;
 257      void *args;
 258 {
 259   // our various things...
 260   ffi_cif       *cif;
 261   void         **arg_area;
 262
 263   cif         = closure->cif;
 264   arg_area    = (void**) alloca (cif->nargs * sizeof (void*));
 265
 266   /* this call will initialize ARG_AREA, such that each
 267    * element in that array points to the corresponding
 268    * value on the stack; and if the function returns
 269    * a structure, it will re-set RESP to point to the
 270    * structure return address.  */
 271
 272   ffi_prep_incoming_args_SYSV(args, respp, arg_area, cif);
 273
 274   (closure->fun) (cif, *respp, arg_area, closure->user_data);
 275
 276   return cif->flags;
 277 }
 278
 279 /*@-exportheader@*/
 280 static void
 281 ffi_prep_incoming_args_SYSV(char *stack, void **rvalue,
 282                             void **avalue, ffi_cif *cif)
 283 /*@=exportheader@*/
 284 {
 285   register unsigned int i;
 286   register void **p_argv;
 287   register char *argp;
 288   register ffi_type **p_arg;
 289
 290   argp = stack;
 291
 292   if ( cif->flags == FFI_TYPE_STRUCT ) {
 293     *rvalue = *(void **) argp;
 294     argp += 4;
 295   }
 296
 297   p_argv = avalue;
 298
 299   for (i = cif->nargs, p_arg = cif->arg_types; (i != 0); i--, p_arg++)
 300     {
 301       size_t z;
 302
 303       /* Align if necessary */
 304       if ((sizeof(int) - 1) & (unsigned) argp) {
 305         argp = (char *) ALIGN(argp, sizeof(int));
 306       }
 307
 308       z = (*p_arg)->size;
 309
 310       /* because we're little endian, this is what it turns into.   */
 311
 312       *p_argv = (void*) argp;
 313
 314       p_argv++;
 315       argp += z;
 316     }
 317
 318   return;
 319 }
 320
 321 /* How to make a trampoline.  Derived from gcc/config/i386/i386.c. */
 322
 323 #define FFI_INIT_TRAMPOLINE(TRAMP,FUN,CTX) \
 324 ({ unsigned char *__tramp = (unsigned char*)(TRAMP); \
 325    unsigned int  __fun = (unsigned int)(FUN); \
 326    unsigned int  __ctx = (unsigned int)(CTX); \
 327    unsigned int  __dis = __fun - ((unsigned int) __tramp + FFI_TRAMPOLINE_SIZE); \
 328    *(unsigned char*) &__tramp[0] = 0xb8; \
 329    *(unsigned int*)  &__tramp[1] = __ctx; /* movl __ctx, %eax */ \
 330    *(unsigned char *)  &__tramp[5] = 0xe9; \
 331    *(unsigned int*)  &__tramp[6] = __dis; /* jmp __fun  */ \
 332  })
 333
 334
 335 /* the cif must already be prep'ed */
 336
 337 ffi_status
 338 ffi_prep_closure (ffi_closure* closure,
 339                   ffi_cif* cif,
 340                   void (*fun)(ffi_cif*,void*,void**,void*),
 341                   void *user_data)
 342 {
 343   FFI_ASSERT (cif->abi == FFI_SYSV);
 344
 345   FFI_INIT_TRAMPOLINE (&closure->tramp[0], \
 346                        &ffi_closure_SYSV,  \
 347                        (void*)closure);
 348
 349   closure->cif  = cif;
 350   closure->user_data = user_data;
 351   closure->fun  = fun;
 352
 353   return FFI_OK;
 354 }
 355
 356 /* ------- Native raw API support -------------------------------- */
 357
 358 #if !FFI_NO_RAW_API
 359
 360 ffi_status
 361 ffi_prep_raw_closure (ffi_raw_closure* closure,
 362                       ffi_cif* cif,
 363                       void (*fun)(ffi_cif*,void*,ffi_raw*,void*),
 364                       void *user_data)
 365 {
 366   int i;
 367
 368   FFI_ASSERT (cif->abi == FFI_SYSV);
 369
 370   // we currently don't support certain kinds of arguments for raw
 371   // closures.  This should be implemented by a separate assembly language
 372   // routine, since it would require argument processing, something we
 373   // don't do now for performance.
 374
 375   for (i = cif->nargs-1; i >= 0; i--)
 376     {
 377       FFI_ASSERT (cif->arg_types[i]->type != FFI_TYPE_STRUCT);
 378       FFI_ASSERT (cif->arg_types[i]->type != FFI_TYPE_LONGDOUBLE);
 379     }
 380
 381
 382   FFI_INIT_TRAMPOLINE (&closure->tramp[0], &ffi_closure_raw_SYSV,
 383                        (void*)closure);
 384
 385   closure->cif  = cif;
 386   closure->user_data = user_data;
 387   closure->fun  = fun;
 388
 389   return FFI_OK;
 390 }
 391
 392 static void
 393 ffi_prep_args_raw(char *stack, extended_cif *ecif)
 394 {
 395   memcpy (stack, ecif->avalue, ecif->cif->bytes);
 396 }
 397
 398 /* we borrow this routine from libffi (it must be changed, though, to
 399  * actually call the function passed in the first argument.  as of
 400  * libffi-1.20, this is not the case.)
 401  */
 402
 403 extern void
 404 ffi_call_SYSV(void (*)(char *, extended_cif *),
 405               /*@out@*/ extended_cif *,
 406               unsigned, unsigned,
 407               /*@out@*/ unsigned *,
 408               void (*fn)());
 409
 410 #ifdef X86_WIN32
 411 extern void
 412 ffi_call_STDCALL(void (*)(char *, extended_cif *),
 413               /*@out@*/ extended_cif *,
 414               unsigned, unsigned,
 415               /*@out@*/ unsigned *,
 416               void (*fn)());
 417 #endif /* X86_WIN32 */
 418
 419 void
 420 ffi_raw_call(/*@dependent@*/ ffi_cif *cif,
 421              void (*fn)(),
 422              /*@out@*/ void *rvalue,
 423              /*@dependent@*/ ffi_raw *fake_avalue)
 424 {
 425   extended_cif ecif;
 426   void **avalue = (void **)fake_avalue;
 427
 428   ecif.cif = cif;
 429   ecif.avalue = avalue;
 430
 431   /* If the return value is a struct and we don't have a return */
 432   /* value address then we need to make one                     */
 433
 434   if ((rvalue == NULL) &&
 435       (cif->rtype->type == FFI_TYPE_STRUCT))
 436     {
 437       /*@-sysunrecog@*/
 438       ecif.rvalue = alloca(cif->rtype->size);
 439       /*@=sysunrecog@*/
 440     }
 441   else
 442     ecif.rvalue = rvalue;
 443
 444
 445   switch (cif->abi)
 446     {
 447     case FFI_SYSV:
 448       /*@-usedef@*/
 449       ffi_call_SYSV(ffi_prep_args_raw, &ecif, cif->bytes,
 450                     cif->flags, ecif.rvalue, fn);
 451       /*@=usedef@*/
 452       break;
 453 #ifdef X86_WIN32
 454     case FFI_STDCALL:
 455       /*@-usedef@*/
 456       ffi_call_STDCALL(ffi_prep_args_raw, &ecif, cif->bytes,
 457                     cif->flags, ecif.rvalue, fn);
 458       /*@=usedef@*/
 459       break;
 460 #endif /* X86_WIN32 */
 461     default:
 462       FFI_ASSERT(0);
 463       break;
 464     }
 465 }
 466
 467 #endif
 468
 469 #endif /* __x86_64__  */