libguile/foreign.c

   1 /* Copyright (C) 2010  Free Software Foundation, Inc.
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public License
   5  * as published by the Free Software Foundation; either version 3 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301 USA
  17  */
  18
  19 #if HAVE_CONFIG_H
  20 #  include <config.h>
  21 #endif
  22
  23 #include <ffi.h>
  24
  25 #include <alignof.h>
  26 #include <string.h>
  27 #include "libguile/_scm.h"
  28 #include "libguile/bytevectors.h"
  29 #include "libguile/instructions.h"
  30 #include "libguile/foreign.h"
  31
  32 \f
  33
  34 SCM_SYMBOL (sym_void, "void");
  35 SCM_SYMBOL (sym_float, "float");
  36 SCM_SYMBOL (sym_double, "double");
  37 SCM_SYMBOL (sym_uint8, "uint8");
  38 SCM_SYMBOL (sym_int8, "int8");
  39 SCM_SYMBOL (sym_uint16, "uint16");
  40 SCM_SYMBOL (sym_int16, "int16");
  41 SCM_SYMBOL (sym_uint32, "uint32");
  42 SCM_SYMBOL (sym_int32, "int32");
  43 SCM_SYMBOL (sym_uint64, "uint64");
  44 SCM_SYMBOL (sym_int64, "int64");
  45 SCM_SYMBOL (sym_int, "int");
  46 SCM_SYMBOL (sym_long, "long");
  47 SCM_SYMBOL (sym_unsigned_int, "unsigned-int");
  48 SCM_SYMBOL (sym_unsigned_long, "unsigned-long");
  49 SCM_SYMBOL (sym_size_t, "size_t");
  50
  51 /* that's for pointers, you know. */
  52 SCM_SYMBOL (sym_asterisk, "*");
  53
  54 SCM_SYMBOL (sym_null, "%null-pointer");
  55
  56 /* The cell representing the null pointer.  */
  57 static const scm_t_bits null_pointer[2] =
  58   {
  59     scm_tc7_foreign | (SCM_FOREIGN_TYPE_VOID << 8UL),
  60     0
  61   };
  62
  63 static SCM cif_to_procedure (SCM cif, SCM func_ptr);
  64
  65
  66 static SCM foreign_weak_refs = SCM_BOOL_F;
  67
  68 static void
  69 register_weak_reference (SCM from, SCM to)
  70 {
  71   scm_hashq_set_x (foreign_weak_refs, from, to);
  72 }
  73
  74 static void
  75 foreign_finalizer_trampoline (GC_PTR ptr, GC_PTR data)
  76 {
  77   scm_t_foreign_finalizer finalizer = data;
  78   finalizer (SCM_FOREIGN_POINTER (PTR2SCM (ptr), void));
  79 }
  80
  81 SCM
  82 scm_take_foreign_pointer (scm_t_foreign_type type, void *ptr, size_t len,
  83                           scm_t_foreign_finalizer finalizer)
  84 {
  85   SCM ret;
  86   scm_t_bits word0;
  87
  88   word0 = (scm_t_bits)(scm_tc7_foreign | (type<<8)
  89                        | (finalizer ? (1<<16) : 0) | (len<<17));
  90   if (SCM_UNLIKELY ((word0 >> 17) != len))
  91     scm_out_of_range ("scm_take_foreign_pointer", scm_from_size_t (len));
  92
  93   ret = PTR2SCM (scm_gc_malloc_pointerless (sizeof (scm_t_bits) * 2,
  94                                             "foreign"));
  95   SCM_SET_CELL_WORD_0 (ret, word0);
  96   SCM_SET_CELL_WORD_1 (ret, (scm_t_bits)ptr);
  97
  98   if (finalizer)
  99     {
 100       /* Register a finalizer for the newly created instance.  */
 101       GC_finalization_proc prev_finalizer;
 102       GC_PTR prev_finalizer_data;
 103       GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (ret),
 104                                       foreign_finalizer_trampoline,
 105                                       finalizer,
 106                                       &prev_finalizer,
 107                                       &prev_finalizer_data);
 108     }
 109
 110   return ret;
 111 }
 112
 113 SCM_DEFINE (scm_foreign_ref, "foreign-ref", 1, 0, 0,
 114             (SCM foreign),
 115             "Reference the foreign value wrapped by @var{foreign}.\n\n"
 116             "The value will be referenced according to its type.")
 117 #define FUNC_NAME s_scm_foreign_ref
 118 {
 119   scm_t_foreign_type ftype;
 120   scm_t_uint8 *ptr;
 121
 122   SCM_VALIDATE_FOREIGN (1, foreign);
 123   ptr = SCM_FOREIGN_POINTER (foreign, scm_t_uint8);
 124   ftype = SCM_FOREIGN_TYPE (foreign);
 125
 126   /* FIXME: is there a window in which we can see ptr but not foreign? */
 127   /* FIXME: accessing unaligned pointers */
 128   switch (ftype)
 129     {
 130     case SCM_FOREIGN_TYPE_VOID:
 131       return scm_from_ulong ((unsigned long)ptr);
 132     case SCM_FOREIGN_TYPE_FLOAT:
 133       return scm_from_double (*(float*)ptr);
 134     case SCM_FOREIGN_TYPE_DOUBLE:
 135       return scm_from_double (*(double*)ptr);
 136     case SCM_FOREIGN_TYPE_UINT8:
 137       return scm_from_uint8 (*(scm_t_uint8*)ptr);
 138     case SCM_FOREIGN_TYPE_INT8:
 139       return scm_from_int8 (*(scm_t_int8*)ptr);
 140     case SCM_FOREIGN_TYPE_UINT16:
 141       return scm_from_uint16 (*(scm_t_uint16*)ptr);
 142     case SCM_FOREIGN_TYPE_INT16:
 143       return scm_from_int16 (*(scm_t_int16*)ptr);
 144     case SCM_FOREIGN_TYPE_UINT32:
 145       return scm_from_uint32 (*(scm_t_uint32*)ptr);
 146     case SCM_FOREIGN_TYPE_INT32:
 147       return scm_from_int32 (*(scm_t_int32*)ptr);
 148     case SCM_FOREIGN_TYPE_UINT64:
 149       return scm_from_uint64 (*(scm_t_uint64*)ptr);
 150     case SCM_FOREIGN_TYPE_INT64:
 151       return scm_from_int64 (*(scm_t_int64*)ptr);
 152     default:
 153       scm_wrong_type_arg_msg (FUNC_NAME, 1, foreign, "foreign");
 154     }
 155 }
 156 #undef FUNC_NAME
 157
 158 SCM_DEFINE (scm_foreign_set_x, "foreign-set!", 2, 0, 0,
 159             (SCM foreign, SCM val),
 160             "Set the foreign value wrapped by @var{foreign}.\n\n"
 161             "The value will be set according to its type.")
 162 #define FUNC_NAME s_scm_foreign_set_x
 163 {
 164   scm_t_foreign_type ftype;
 165   scm_t_uint8 *ptr;
 166
 167   SCM_VALIDATE_FOREIGN (1, foreign);
 168   ptr = SCM_FOREIGN_POINTER (foreign, scm_t_uint8);
 169   ftype = SCM_FOREIGN_TYPE (foreign);
 170
 171   /* FIXME: is there a window in which we can see ptr but not foreign? */
 172   /* FIXME: unaligned access */
 173   switch (ftype)
 174     {
 175     case SCM_FOREIGN_TYPE_VOID:
 176       SCM_SET_CELL_WORD_1 (foreign, scm_to_ulong (val));
 177       break;
 178     case SCM_FOREIGN_TYPE_FLOAT:
 179       *(float*)ptr = scm_to_double (val);
 180       break;
 181     case SCM_FOREIGN_TYPE_DOUBLE:
 182       *(double*)ptr = scm_to_double (val);
 183       break;
 184     case SCM_FOREIGN_TYPE_UINT8:
 185       *(scm_t_uint8*)ptr = scm_to_uint8 (val);
 186       break;
 187     case SCM_FOREIGN_TYPE_INT8:
 188       *(scm_t_int8*)ptr = scm_to_int8 (val);
 189       break;
 190     case SCM_FOREIGN_TYPE_UINT16:
 191       *(scm_t_uint16*)ptr = scm_to_uint16 (val);
 192       break;
 193     case SCM_FOREIGN_TYPE_INT16:
 194       *(scm_t_int16*)ptr = scm_to_int16 (val);
 195       break;
 196     case SCM_FOREIGN_TYPE_UINT32:
 197       *(scm_t_uint32*)ptr = scm_to_uint32 (val);
 198       break;
 199     case SCM_FOREIGN_TYPE_INT32:
 200       *(scm_t_int32*)ptr = scm_to_int32 (val);
 201       break;
 202     case SCM_FOREIGN_TYPE_UINT64:
 203       *(scm_t_uint64*)ptr = scm_to_uint64 (val);
 204       break;
 205     case SCM_FOREIGN_TYPE_INT64:
 206       *(scm_t_int64*)ptr = scm_to_int64 (val);
 207       break;
 208     default:
 209       scm_wrong_type_arg_msg (FUNC_NAME, 1, val, "foreign");
 210     }
 211
 212   return SCM_UNSPECIFIED;
 213 }
 214 #undef FUNC_NAME
 215
 216 SCM_DEFINE (scm_foreign_to_bytevector, "foreign->bytevector", 1, 3, 0,
 217             (SCM foreign, SCM uvec_type, SCM offset, SCM len),
 218             "Return a bytevector aliasing the memory pointed to by\n"
 219             "@var{foreign}.\n\n"
 220             "@var{foreign} must be a void pointer, a foreign whose type is\n"
 221             "@var{void}. By default, the resulting bytevector will alias\n"
 222             "all of the memory pointed to by @var{foreign}, from beginning\n"
 223             "to end, treated as a @code{vu8} array.\n\n"
 224             "The user may specify an alternate default interpretation for\n"
 225             "the memory by passing the @var{uvec_type} argument, to indicate\n"
 226             "that the memory is an array of elements of that type.\n"
 227             "@var{uvec_type} should be something that\n"
 228             "@code{uniform-vector-element-type} would return, like @code{f32}\n"
 229             "or @code{s16}.\n\n"
 230             "Users may also specify that the bytevector should only alias a\n"
 231             "subset of the memory, by specifying @var{offset} and @var{len}\n"
 232             "arguments.")
 233 #define FUNC_NAME s_scm_foreign_to_bytevector
 234 {
 235   SCM ret;
 236   scm_t_int8 *ptr;
 237   size_t boffset, blen;
 238   scm_t_array_element_type btype;
 239
 240   SCM_VALIDATE_FOREIGN_TYPED (1, foreign, VOID);
 241   ptr = SCM_FOREIGN_POINTER (foreign, scm_t_int8);
 242
 243   if (SCM_UNLIKELY (ptr == NULL))
 244     scm_misc_error (FUNC_NAME, "null pointer dereference", SCM_EOL);
 245
 246   if (SCM_UNBNDP (uvec_type))
 247     btype = SCM_ARRAY_ELEMENT_TYPE_VU8;
 248   else
 249     {
 250       int i;
 251       for (i = 0; i <= SCM_ARRAY_ELEMENT_TYPE_LAST; i++)
 252         if (scm_is_eq (uvec_type, scm_i_array_element_types[i]))
 253           break;
 254       switch (i)
 255         {
 256         case SCM_ARRAY_ELEMENT_TYPE_VU8:
 257         case SCM_ARRAY_ELEMENT_TYPE_U8:
 258         case SCM_ARRAY_ELEMENT_TYPE_S8:
 259         case SCM_ARRAY_ELEMENT_TYPE_U16:
 260         case SCM_ARRAY_ELEMENT_TYPE_S16:
 261         case SCM_ARRAY_ELEMENT_TYPE_U32:
 262         case SCM_ARRAY_ELEMENT_TYPE_S32:
 263         case SCM_ARRAY_ELEMENT_TYPE_U64:
 264         case SCM_ARRAY_ELEMENT_TYPE_S64:
 265         case SCM_ARRAY_ELEMENT_TYPE_F32:
 266         case SCM_ARRAY_ELEMENT_TYPE_F64:
 267         case SCM_ARRAY_ELEMENT_TYPE_C32:
 268         case SCM_ARRAY_ELEMENT_TYPE_C64:
 269           btype = i;
 270           break;
 271         default:
 272           scm_wrong_type_arg_msg (FUNC_NAME, SCM_ARG1, uvec_type,
 273                                   "uniform vector type");
 274         }
 275     }
 276
 277   if (SCM_UNBNDP (offset))
 278     boffset = 0;
 279   else if (SCM_FOREIGN_LEN (foreign))
 280     boffset = scm_to_unsigned_integer (offset, 0,
 281                                        SCM_FOREIGN_LEN (foreign) - 1);
 282   else
 283     boffset = scm_to_size_t (offset);
 284
 285   if (SCM_UNBNDP (len))
 286     {
 287       if (SCM_FOREIGN_LEN (foreign))
 288         blen = SCM_FOREIGN_LEN (foreign) - boffset;
 289       else
 290         scm_misc_error (FUNC_NAME,
 291                         "length needed to convert foreign pointer to bytevector",
 292                         SCM_EOL);
 293     }
 294   else
 295     {
 296       if (SCM_FOREIGN_LEN (foreign))
 297         blen = scm_to_unsigned_integer (len, 0,
 298                                         SCM_FOREIGN_LEN (foreign) - boffset);
 299       else
 300         blen = scm_to_size_t (len);
 301     }
 302
 303   ret = scm_c_take_typed_bytevector (ptr + boffset, blen, btype);
 304   register_weak_reference (ret, foreign);
 305   return ret;
 306 }
 307 #undef FUNC_NAME
 308
 309 SCM_DEFINE (scm_bytevector_to_foreign, "bytevector->foreign", 1, 2, 0,
 310             (SCM bv, SCM offset, SCM len),
 311             "Return a foreign pointer aliasing the memory pointed to by\n"
 312             "@var{bv}.\n\n"
 313             "The resulting foreign will be a void pointer, a foreign whose\n"
 314             "type is @code{void}. By default it will alias all of the\n"
 315             "memory pointed to by @var{bv}, from beginning to end.\n\n"
 316             "Users may explicily specify that the foreign should only alias a\n"
 317             "subset of the memory, by specifying @var{offset} and @var{len}\n"
 318             "arguments.")
 319 #define FUNC_NAME s_scm_bytevector_to_foreign
 320 {
 321   SCM ret;
 322   scm_t_int8 *ptr;
 323   size_t boffset, blen;
 324
 325   SCM_VALIDATE_BYTEVECTOR (1, bv);
 326   ptr = SCM_BYTEVECTOR_CONTENTS (bv);
 327
 328   if (SCM_UNBNDP (offset))
 329     boffset = 0;
 330   else
 331     boffset = scm_to_unsigned_integer (offset, 0,
 332                                        SCM_BYTEVECTOR_LENGTH (bv) - 1);
 333
 334   if (SCM_UNBNDP (len))
 335     blen = SCM_BYTEVECTOR_LENGTH (bv) - boffset;
 336   else
 337     blen = scm_to_unsigned_integer (len, 0,
 338                                     SCM_BYTEVECTOR_LENGTH (bv) - boffset);
 339
 340   ret = scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID, ptr + boffset, blen,
 341                                   NULL);
 342   register_weak_reference (ret, bv);
 343   return ret;
 344 }
 345 #undef FUNC_NAME
 346
 347 SCM_DEFINE (scm_foreign_set_finalizer_x, "foreign-set-finalizer!", 2, 0, 0,
 348             (SCM foreign, SCM finalizer),
 349             "Arrange for the C procedure wrapped by @var{finalizer} to be\n"
 350             "called on the pointer wrapped by @var{foreign} when @var{foreign}\n"
 351             "becomes unreachable. Note: the C procedure should not call into\n"
 352             "Scheme. If you need a Scheme finalizer, use guardians.")
 353 #define FUNC_NAME s_scm_foreign_set_finalizer_x
 354 {
 355   void *c_finalizer;
 356   GC_finalization_proc prev_finalizer;
 357   GC_PTR prev_finalizer_data;
 358
 359   SCM_VALIDATE_FOREIGN_TYPED (1, foreign, VOID);
 360   SCM_VALIDATE_FOREIGN_TYPED (2, finalizer, VOID);
 361
 362   c_finalizer = SCM_FOREIGN_POINTER (finalizer, void);
 363
 364   SCM_SET_CELL_WORD_0 (foreign, SCM_CELL_WORD_0 (foreign) | (1<<16));
 365
 366   GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (foreign),
 367                                   foreign_finalizer_trampoline,
 368                                   c_finalizer,
 369                                   &prev_finalizer,
 370                                   &prev_finalizer_data);
 371
 372   return SCM_UNSPECIFIED;
 373 }
 374 #undef FUNC_NAME
 375
 376 \f
 377
 378 void
 379 scm_i_foreign_print (SCM foreign, SCM port, scm_print_state *pstate)
 380 {
 381   scm_puts ("#<foreign ", port);
 382   switch (SCM_FOREIGN_TYPE (foreign))
 383     {
 384     case SCM_FOREIGN_TYPE_FLOAT:
 385       scm_puts ("float ", port);
 386       break;
 387     case SCM_FOREIGN_TYPE_DOUBLE:
 388       scm_puts ("double ", port);
 389       break;
 390     case SCM_FOREIGN_TYPE_UINT8:
 391       scm_puts ("uint8 ", port);
 392       break;
 393     case SCM_FOREIGN_TYPE_INT8:
 394       scm_puts ("int8 ", port);
 395       break;
 396     case SCM_FOREIGN_TYPE_UINT16:
 397       scm_puts ("uint16 ", port);
 398       break;
 399     case SCM_FOREIGN_TYPE_INT16:
 400       scm_puts ("int16 ", port);
 401       break;
 402     case SCM_FOREIGN_TYPE_UINT32:
 403       scm_puts ("uint32 ", port);
 404       break;
 405     case SCM_FOREIGN_TYPE_INT32:
 406       scm_puts ("int32 ", port);
 407       break;
 408     case SCM_FOREIGN_TYPE_UINT64:
 409       scm_puts ("uint64 ", port);
 410       break;
 411     case SCM_FOREIGN_TYPE_INT64:
 412       scm_puts ("int64 ", port);
 413       break;
 414     case SCM_FOREIGN_TYPE_VOID:
 415       scm_puts ("pointer ", port);
 416       break;
 417     default:
 418       scm_wrong_type_arg_msg ("%print-foreign", 1, foreign, "foreign");
 419     }
 420   scm_display (scm_foreign_ref (foreign), port);
 421   scm_putc ('>', port);
 422 }
 423
 424 \f
 425
 426
 427 #define ROUND_UP(len,align) (align?(((len-1)|(align-1))+1):len)
 428
 429 SCM_DEFINE (scm_alignof, "alignof", 1, 0, 0, (SCM type), "")
 430 #define FUNC_NAME s_scm_alignof
 431 {
 432   if (SCM_I_INUMP (type))
 433     {
 434       switch (SCM_I_INUM (type))
 435         {
 436         case SCM_FOREIGN_TYPE_FLOAT:
 437           return scm_from_size_t (alignof (float));
 438         case SCM_FOREIGN_TYPE_DOUBLE:
 439           return scm_from_size_t (alignof (double));
 440         case SCM_FOREIGN_TYPE_UINT8:
 441           return scm_from_size_t (alignof (scm_t_uint8));
 442         case SCM_FOREIGN_TYPE_INT8:
 443           return scm_from_size_t (alignof (scm_t_int8));
 444         case SCM_FOREIGN_TYPE_UINT16:
 445           return scm_from_size_t (alignof (scm_t_uint16));
 446         case SCM_FOREIGN_TYPE_INT16:
 447           return scm_from_size_t (alignof (scm_t_int16));
 448         case SCM_FOREIGN_TYPE_UINT32:
 449           return scm_from_size_t (alignof (scm_t_uint32));
 450         case SCM_FOREIGN_TYPE_INT32:
 451           return scm_from_size_t (alignof (scm_t_int32));
 452         case SCM_FOREIGN_TYPE_UINT64:
 453           return scm_from_size_t (alignof (scm_t_uint64));
 454         case SCM_FOREIGN_TYPE_INT64:
 455           return scm_from_size_t (alignof (scm_t_int64));
 456         default:
 457           scm_wrong_type_arg (FUNC_NAME, 1, type);
 458         }
 459     }
 460   else if (scm_is_eq (type, sym_asterisk))
 461     /* a pointer */
 462     return scm_from_size_t (alignof (void*));
 463   else if (scm_is_pair (type))
 464     /* a struct, yo */
 465     return scm_alignof (scm_car (type));
 466   else
 467     scm_wrong_type_arg (FUNC_NAME, 1, type);
 468 }
 469 #undef FUNC_NAME
 470
 471 SCM_DEFINE (scm_sizeof, "sizeof", 1, 0, 0, (SCM type), "")
 472 #define FUNC_NAME s_scm_sizeof
 473 {
 474   if (SCM_I_INUMP (type))
 475     {
 476       switch (SCM_I_INUM (type))
 477         {
 478         case SCM_FOREIGN_TYPE_FLOAT:
 479           return scm_from_size_t (sizeof (float));
 480         case SCM_FOREIGN_TYPE_DOUBLE:
 481           return scm_from_size_t (sizeof (double));
 482         case SCM_FOREIGN_TYPE_UINT8:
 483           return scm_from_size_t (sizeof (scm_t_uint8));
 484         case SCM_FOREIGN_TYPE_INT8:
 485           return scm_from_size_t (sizeof (scm_t_int8));
 486         case SCM_FOREIGN_TYPE_UINT16:
 487           return scm_from_size_t (sizeof (scm_t_uint16));
 488         case SCM_FOREIGN_TYPE_INT16:
 489           return scm_from_size_t (sizeof (scm_t_int16));
 490         case SCM_FOREIGN_TYPE_UINT32:
 491           return scm_from_size_t (sizeof (scm_t_uint32));
 492         case SCM_FOREIGN_TYPE_INT32:
 493           return scm_from_size_t (sizeof (scm_t_int32));
 494         case SCM_FOREIGN_TYPE_UINT64:
 495           return scm_from_size_t (sizeof (scm_t_uint64));
 496         case SCM_FOREIGN_TYPE_INT64:
 497           return scm_from_size_t (sizeof (scm_t_int64));
 498         default:
 499           scm_wrong_type_arg (FUNC_NAME, 1, type);
 500         }
 501     }
 502   else if (scm_is_eq (type, sym_asterisk))
 503     /* a pointer */
 504     return scm_from_size_t (sizeof (void*));
 505   else if (scm_is_pair (type))
 506     {
 507       /* a struct */
 508       size_t off = 0;
 509       while (scm_is_pair (type))
 510         {
 511           off = ROUND_UP (off, scm_to_size_t (scm_alignof (scm_car (type))));
 512           off += scm_to_size_t (scm_sizeof (scm_car (type)));
 513           type = scm_cdr (type);
 514         }
 515       return scm_from_size_t (off);
 516     }
 517   else
 518     scm_wrong_type_arg (FUNC_NAME, 1, type);
 519 }
 520 #undef FUNC_NAME
 521
 522
 523 /* return 1 on success, 0 on failure */
 524 static int
 525 parse_ffi_type (SCM type, int return_p, long *n_structs, long *n_struct_elts)
 526 {
 527   if (SCM_I_INUMP (type))
 528     {
 529       if ((SCM_I_INUM (type) < 0 )
 530           || (SCM_I_INUM (type) > SCM_FOREIGN_TYPE_LAST))
 531         return 0;
 532       else if (SCM_I_INUM (type) == SCM_FOREIGN_TYPE_VOID && !return_p)
 533         return 0;
 534       else
 535         return 1;
 536     }
 537   else if (scm_is_eq (type, sym_asterisk))
 538     /* a pointer */
 539     return 1;
 540   else
 541     {
 542       long len;
 543
 544       len = scm_ilength (type);
 545       if (len < 1)
 546         return 0;
 547       while (len--)
 548         {
 549           if (!parse_ffi_type (scm_car (type), 0, n_structs, n_struct_elts))
 550             return 0;
 551           (*n_struct_elts)++;
 552           type = scm_cdr (type);
 553         }
 554       (*n_structs)++;
 555       return 1;
 556     }
 557 }
 558
 559 static void
 560 fill_ffi_type (SCM type, ffi_type *ftype, ffi_type ***type_ptrs,
 561                ffi_type **types)
 562 {
 563   if (SCM_I_INUMP (type))
 564     {
 565       switch (SCM_I_INUM (type))
 566         {
 567         case SCM_FOREIGN_TYPE_FLOAT:
 568           *ftype = ffi_type_float;
 569           return;
 570         case SCM_FOREIGN_TYPE_DOUBLE:
 571           *ftype = ffi_type_double;
 572           return;
 573         case SCM_FOREIGN_TYPE_UINT8:
 574           *ftype = ffi_type_uint8;
 575           return;
 576         case SCM_FOREIGN_TYPE_INT8:
 577           *ftype = ffi_type_sint8;
 578           return;
 579         case SCM_FOREIGN_TYPE_UINT16:
 580           *ftype = ffi_type_uint16;
 581           return;
 582         case SCM_FOREIGN_TYPE_INT16:
 583           *ftype = ffi_type_sint16;
 584           return;
 585         case SCM_FOREIGN_TYPE_UINT32:
 586           *ftype = ffi_type_uint32;
 587           return;
 588         case SCM_FOREIGN_TYPE_INT32:
 589           *ftype = ffi_type_sint32;
 590           return;
 591         case SCM_FOREIGN_TYPE_UINT64:
 592           *ftype = ffi_type_uint64;
 593           return;
 594         case SCM_FOREIGN_TYPE_INT64:
 595           *ftype = ffi_type_sint64;
 596           return;
 597         case SCM_FOREIGN_TYPE_VOID:
 598           *ftype = ffi_type_void;
 599           return;
 600         default:
 601           scm_wrong_type_arg_msg ("make-foreign-function", 0, type,
 602                                   "foreign type");
 603         }
 604     }
 605   else if (scm_is_eq (type, sym_asterisk))
 606     /* a pointer */
 607     {
 608       *ftype = ffi_type_pointer;
 609       return;
 610     }
 611   else
 612     {
 613       long i, len;
 614
 615       len = scm_ilength (type);
 616
 617       ftype->size = 0;
 618       ftype->alignment = 0;
 619       ftype->type = FFI_TYPE_STRUCT;
 620       ftype->elements = *type_ptrs;
 621       *type_ptrs += len + 1;
 622
 623       for (i = 0; i < len; i++)
 624         {
 625           ftype->elements[i] = *types;
 626           *types += 1;
 627           fill_ffi_type (scm_car (type), ftype->elements[i],
 628                          type_ptrs, types);
 629           type = scm_cdr (type);
 630         }
 631       ftype->elements[i] = NULL;
 632     }
 633 }
 634
 635 SCM_DEFINE (scm_make_foreign_function, "make-foreign-function", 3, 0, 0,
 636             (SCM return_type, SCM func_ptr, SCM arg_types),
 637             "foo")
 638 #define FUNC_NAME s_scm_make_foreign_function
 639 {
 640   SCM walk, scm_cif;
 641   long i, nargs, n_structs, n_struct_elts;
 642   size_t cif_len;
 643   char *mem;
 644   ffi_cif *cif;
 645   ffi_type **type_ptrs;
 646   ffi_type *types;
 647
 648   SCM_VALIDATE_FOREIGN_TYPED (2, func_ptr, VOID);
 649   nargs = scm_ilength (arg_types);
 650   SCM_ASSERT (nargs >= 0, arg_types, 3, FUNC_NAME);
 651   /* fixme: assert nargs < 1<<32 */
 652   n_structs = n_struct_elts = 0;
 653
 654   /* For want of talloc, we're going to have to do this in two passes: first we
 655      figure out how much memory is needed for all types, then we allocate the
 656      cif and the types all in one block. */
 657   if (!parse_ffi_type (return_type, 1, &n_structs, &n_struct_elts))
 658     scm_wrong_type_arg (FUNC_NAME, 1, return_type);
 659   for (walk = arg_types; scm_is_pair (walk); walk = scm_cdr (walk))
 660     if (!parse_ffi_type (scm_car (walk), 0, &n_structs, &n_struct_elts))
 661       scm_wrong_type_arg (FUNC_NAME, 3, scm_car (walk));
 662
 663   /* the memory: with space for the cif itself */
 664   cif_len = sizeof (ffi_cif);
 665
 666   /* then ffi_type pointers: one for each arg, one for each struct
 667      element, and one for each struct (for null-termination) */
 668   cif_len = (ROUND_UP (cif_len, alignof(void*))
 669              + (nargs + n_structs + n_struct_elts)*sizeof(void*));
 670
 671   /* then the ffi_type structs themselves, one per arg and struct element, and
 672      one for the return val */
 673   cif_len = (ROUND_UP (cif_len, alignof(ffi_type))
 674              + (nargs + n_struct_elts + 1)*sizeof(ffi_type));
 675
 676   mem = scm_gc_malloc_pointerless (cif_len, "foreign");
 677   scm_cif = scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID, mem,
 678                                       cif_len, NULL);
 679   cif = (ffi_cif *) mem;
 680
 681   /* reuse cif_len to walk through the mem */
 682   cif_len = ROUND_UP (sizeof (ffi_cif), alignof(void*));
 683   type_ptrs = (ffi_type**)(mem + cif_len);
 684   cif_len = ROUND_UP (cif_len
 685                       + (nargs + n_structs + n_struct_elts)*sizeof(void*),
 686                       alignof(ffi_type));
 687   types = (ffi_type*)(mem + cif_len);
 688
 689   /* whew. now knit the pointers together. */
 690   cif->rtype = types++;
 691   fill_ffi_type (return_type, cif->rtype, &type_ptrs, &types);
 692   cif->arg_types = type_ptrs;
 693   type_ptrs += nargs;
 694   for (walk = arg_types, i = 0; scm_is_pair (walk); walk = scm_cdr (walk), i++)
 695     {
 696       cif->arg_types[i] = types++;
 697       fill_ffi_type (scm_car (walk), cif->arg_types[i], &type_ptrs, &types);
 698     }
 699
 700   /* round out the cif, and we're done. */
 701   cif->abi = FFI_DEFAULT_ABI;
 702   cif->nargs = nargs;
 703   cif->bytes = 0;
 704   cif->flags = 0;
 705
 706   if (FFI_OK != ffi_prep_cif (cif, FFI_DEFAULT_ABI, cif->nargs, cif->rtype,
 707                               cif->arg_types))
 708     scm_misc_error (FUNC_NAME, "ffi_prep_cif failed", SCM_EOL);
 709
 710   return cif_to_procedure (scm_cif, func_ptr);
 711 }
 712 #undef FUNC_NAME
 713
 714 \f
 715
 716 /* Pre-generate trampolines for less than 10 arguments. */
 717
 718 #ifdef WORDS_BIGENDIAN
 719 #define OBJCODE_HEADER 0, 0, 0, 8, 0, 0, 0, 40
 720 #define META_HEADER    0, 0, 0, 32, 0, 0, 0, 0
 721 #else
 722 #define OBJCODE_HEADER 8, 0, 0, 0, 40, 0, 0, 0
 723 #define META_HEADER    32, 0, 0, 0, 0, 0, 0, 0
 724 #endif
 725
 726 #define CODE(nreq)                                                      \
 727   OBJCODE_HEADER,                                                       \
 728   /* 0 */ scm_op_assert_nargs_ee, 0, nreq, /* assert number of args */  \
 729   /* 3 */ scm_op_object_ref, 0, /* push the pair with the cif and the function pointer */ \
 730   /* 5 */ scm_op_foreign_call, nreq, /* and call (will return value as well) */ \
 731   /* 7 */ scm_op_nop,                                                   \
 732   /* 8 */ META (3, 7, nreq)
 733
 734 #define META(start, end, nreq)                                          \
 735   META_HEADER,                                                          \
 736   /* 0 */ scm_op_make_eol, /* bindings */                               \
 737   /* 1 */ scm_op_make_eol, /* sources */                                \
 738   /* 2 */ scm_op_make_int8, start, scm_op_make_int8, end, /* arity: from ip N to ip N */ \
 739   /* 6 */ scm_op_make_int8, nreq, /* the arity is N required args */    \
 740   /* 8 */ scm_op_list, 0, 3, /* make a list of those 3 vals */         \
 741   /* 11 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ \
 742   /* 14 */ scm_op_load_symbol, 0, 0, 4, 'n', 'a', 'm', 'e', /* `name' */ \
 743   /* 22 */ scm_op_object_ref, 1, /* the name from the object table */   \
 744   /* 24 */ scm_op_cons, /* make a pair for the properties */            \
 745   /* 25 */ scm_op_list, 0, 4, /* pack bindings, sources, and arities into list */ \
 746   /* 28 */ scm_op_return, /* and return */                              \
 747   /* 29 */ scm_op_nop, scm_op_nop, scm_op_nop                           \
 748   /* 32 */
 749
 750 static const struct
 751 {
 752   scm_t_uint64 dummy; /* ensure 8-byte alignment; perhaps there's a better way */
 753   const scm_t_uint8 bytes[10 * (sizeof (struct scm_objcode) + 8
 754                                 + sizeof (struct scm_objcode) + 32)];
 755 } raw_bytecode = {
 756   0,
 757   {
 758     CODE (0), CODE (1), CODE (2), CODE (3), CODE (4),
 759     CODE (5), CODE (6), CODE (7), CODE (8), CODE (9)
 760   }
 761 };
 762
 763 #undef CODE
 764 #undef META
 765 #undef OBJCODE_HEADER
 766 #undef META_HEADER
 767
 768 /*
 769  (defun generate-objcode-cells (n)
 770    "Generate objcode cells for up to N arguments"
 771    (interactive "p")
 772    (let ((i 0))
 773      (while (< i n)
 774        (insert
 775         (format "    { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + %d) },\n"
 776                 (* (+ 4 4 8 4 4 32) i)))
 777        (insert "    { SCM_BOOL_F, SCM_PACK (0) },\n")
 778        (setq i (1+ i)))))
 779 */
 780 #define STATIC_OBJCODE_TAG                                      \
 781   SCM_PACK (scm_tc7_objcode | (SCM_F_OBJCODE_IS_STATIC << 8))
 782
 783 static const struct
 784 {
 785   scm_t_uint64 dummy; /* alignment */
 786   scm_t_cell cells[10 * 2]; /* 10 double cells */
 787 } objcode_cells = {
 788   0,
 789   /* C-u 1 0 M-x generate-objcode-cells RET */
 790   {
 791     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 0) },
 792     { SCM_BOOL_F, SCM_PACK (0) },
 793     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 56) },
 794     { SCM_BOOL_F, SCM_PACK (0) },
 795     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 112) },
 796     { SCM_BOOL_F, SCM_PACK (0) },
 797     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 168) },
 798     { SCM_BOOL_F, SCM_PACK (0) },
 799     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 224) },
 800     { SCM_BOOL_F, SCM_PACK (0) },
 801     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 280) },
 802     { SCM_BOOL_F, SCM_PACK (0) },
 803     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 336) },
 804     { SCM_BOOL_F, SCM_PACK (0) },
 805     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 392) },
 806     { SCM_BOOL_F, SCM_PACK (0) },
 807     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 448) },
 808     { SCM_BOOL_F, SCM_PACK (0) },
 809     { STATIC_OBJCODE_TAG, SCM_PACK (raw_bytecode.bytes + 504) },
 810     { SCM_BOOL_F, SCM_PACK (0) }
 811   }
 812 };
 813
 814 static const SCM objcode_trampolines[10] = {
 815   SCM_PACK (objcode_cells.cells+0),
 816   SCM_PACK (objcode_cells.cells+2),
 817   SCM_PACK (objcode_cells.cells+4),
 818   SCM_PACK (objcode_cells.cells+6),
 819   SCM_PACK (objcode_cells.cells+8),
 820   SCM_PACK (objcode_cells.cells+10),
 821   SCM_PACK (objcode_cells.cells+12),
 822   SCM_PACK (objcode_cells.cells+14),
 823   SCM_PACK (objcode_cells.cells+16),
 824   SCM_PACK (objcode_cells.cells+18),
 825 };
 826
 827 static SCM
 828 cif_to_procedure (SCM cif, SCM func_ptr)
 829 {
 830   unsigned nargs = SCM_FOREIGN_POINTER (cif, ffi_cif)->nargs;
 831   SCM objcode, table, ret;
 832
 833   if (nargs < 10)
 834     objcode = objcode_trampolines[nargs];
 835   else
 836     scm_misc_error ("make-foreign-function", "args >= 10 currently unimplemented",
 837                     SCM_EOL);
 838
 839   table = scm_c_make_vector (2, SCM_UNDEFINED);
 840   SCM_SIMPLE_VECTOR_SET (table, 0, scm_cons (cif, func_ptr));
 841   SCM_SIMPLE_VECTOR_SET (table, 1, SCM_BOOL_F); /* name */
 842   ret = scm_make_program (objcode, table, SCM_BOOL_F);
 843
 844   return ret;
 845 }
 846
 847 static void
 848 unpack (ffi_type *type, void *loc, SCM x)
 849 {
 850   switch (type->type)
 851     {
 852     case FFI_TYPE_FLOAT:
 853       *(float*)loc = scm_to_double (x);
 854       break;
 855     case FFI_TYPE_DOUBLE:
 856       *(double*)loc = scm_to_double (x);
 857       break;
 858     case FFI_TYPE_UINT8:
 859       *(scm_t_uint8*)loc = scm_to_uint8 (x);
 860       break;
 861     case FFI_TYPE_SINT8:
 862       *(scm_t_int8*)loc = scm_to_int8 (x);
 863       break;
 864     case FFI_TYPE_UINT16:
 865       *(scm_t_uint16*)loc = scm_to_uint16 (x);
 866       break;
 867     case FFI_TYPE_SINT16:
 868       *(scm_t_int16*)loc = scm_to_int16 (x);
 869       break;
 870     case FFI_TYPE_UINT32:
 871       *(scm_t_uint32*)loc = scm_to_uint32 (x);
 872       break;
 873     case FFI_TYPE_SINT32:
 874       *(scm_t_int32*)loc = scm_to_int32 (x);
 875       break;
 876     case FFI_TYPE_UINT64:
 877       *(scm_t_uint64*)loc = scm_to_uint64 (x);
 878       break;
 879     case FFI_TYPE_SINT64:
 880       *(scm_t_int64*)loc = scm_to_int64 (x);
 881       break;
 882     case FFI_TYPE_STRUCT:
 883       if (!SCM_FOREIGN_TYPED_P (x, VOID))
 884         scm_wrong_type_arg_msg ("foreign-call", 0, x,
 885                                 "foreign void pointer");
 886       if (SCM_FOREIGN_LEN (x) && SCM_FOREIGN_LEN (x) != type->size)
 887         scm_wrong_type_arg_msg ("foreign-call", 0, x,
 888                                 "foreign void pointer of correct length");
 889       memcpy (loc, SCM_FOREIGN_POINTER (x, void), type->size);
 890       break;
 891     case FFI_TYPE_POINTER:
 892       if (!SCM_FOREIGN_TYPED_P (x, VOID))
 893         scm_wrong_type_arg_msg ("foreign-call", 0, x,
 894                                 "foreign void pointer");
 895       *(void**)loc = SCM_FOREIGN_POINTER (x, void);
 896       break;
 897     default:
 898       abort ();
 899     }
 900 }
 901
 902 static SCM
 903 pack (ffi_type *type, void *loc)
 904 {
 905   switch (type->type)
 906     {
 907     case FFI_TYPE_VOID:
 908       return SCM_UNSPECIFIED;
 909     case FFI_TYPE_FLOAT:
 910       return scm_from_double (*(float*)loc);
 911     case FFI_TYPE_DOUBLE:
 912       return scm_from_double (*(double*)loc);
 913     case FFI_TYPE_UINT8:
 914       return scm_from_uint8 (*(scm_t_uint8*)loc);
 915     case FFI_TYPE_SINT8:
 916       return scm_from_int8 (*(scm_t_int8*)loc);
 917     case FFI_TYPE_UINT16:
 918       return scm_from_uint16 (*(scm_t_uint16*)loc);
 919     case FFI_TYPE_SINT16:
 920       return scm_from_int16 (*(scm_t_int16*)loc);
 921     case FFI_TYPE_UINT32:
 922       return scm_from_uint32 (*(scm_t_uint32*)loc);
 923     case FFI_TYPE_SINT32:
 924       return scm_from_int32 (*(scm_t_int32*)loc);
 925     case FFI_TYPE_UINT64:
 926       return scm_from_uint64 (*(scm_t_uint64*)loc);
 927     case FFI_TYPE_SINT64:
 928       return scm_from_int64 (*(scm_t_int64*)loc);
 929     case FFI_TYPE_STRUCT:
 930       {
 931         void *mem = scm_gc_malloc_pointerless (type->size, "foreign");
 932         memcpy (mem, loc, type->size);
 933         return scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID,
 934                                          mem, type->size, NULL);
 935       }
 936     case FFI_TYPE_POINTER:
 937       return scm_take_foreign_pointer (SCM_FOREIGN_TYPE_VOID,
 938                                        *(void**)loc, 0, NULL);
 939     default:
 940       abort ();
 941     }
 942 }
 943
 944 SCM
 945 scm_i_foreign_call (SCM foreign, SCM *argv)
 946 {
 947   /* FOREIGN is the pair that cif_to_procedure set as the 0th element of the
 948      objtable. */
 949   ffi_cif *cif;
 950   void (*func)();
 951   scm_t_uint8 *data;
 952   void *rvalue;
 953   void **args;
 954   unsigned i;
 955   size_t arg_size;
 956   scm_t_ptrdiff off;
 957
 958   cif = SCM_FOREIGN_POINTER (scm_car (foreign), ffi_cif);
 959   func = SCM_FOREIGN_POINTER (scm_cdr (foreign), void);
 960
 961   /* Argument pointers.  */
 962   args = alloca (sizeof(void*) * cif->nargs);
 963
 964   /* Compute the amount of memory needed to store all the argument values.
 965      Note: as of libffi 3.0.9 `cif->bytes' is undocumented and is zero, so it
 966      can't be used for that purpose.  */
 967   for (i = 0, arg_size = 0;
 968        i < cif->nargs;
 969        i++, arg_size)
 970     arg_size += ROUND_UP (cif->arg_types[i]->size,
 971                           cif->arg_types[i]->alignment);
 972
 973   /* Space for argument values, followed by return value.  */
 974   data = alloca (arg_size
 975                  + ROUND_UP (cif->rtype->size, cif->rtype->alignment));
 976
 977   /* unpack argv to native values, setting argv pointers */
 978   off = 0;
 979   for (i = 0; i < cif->nargs; i++)
 980     {
 981       off = ROUND_UP (off, cif->arg_types[i]->alignment);
 982       args[i] = data + off;
 983       unpack (cif->arg_types[i], args[i], argv[i]);
 984       off += cif->arg_types[i]->size;
 985     }
 986   /* prep space for the return value */
 987   off = ROUND_UP (off, cif->rtype->alignment);
 988   rvalue = data + off;
 989
 990   /* off we go! */
 991   ffi_call (cif, func, rvalue, args);
 992
 993   return pack (cif->rtype, rvalue);
 994 }
 995
 996 \f
 997
 998 static void
 999 scm_init_foreign (void)
1000 {
1001 #ifndef SCM_MAGIC_SNARFER
1002 #include "libguile/foreign.x"
1003 #endif
1004   scm_define (sym_void, scm_from_uint8 (SCM_FOREIGN_TYPE_VOID));
1005   scm_define (sym_float, scm_from_uint8 (SCM_FOREIGN_TYPE_FLOAT));
1006   scm_define (sym_double, scm_from_uint8 (SCM_FOREIGN_TYPE_DOUBLE));
1007   scm_define (sym_uint8, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT8));
1008   scm_define (sym_int8, scm_from_uint8 (SCM_FOREIGN_TYPE_INT8));
1009   scm_define (sym_uint16, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16));
1010   scm_define (sym_int16, scm_from_uint8 (SCM_FOREIGN_TYPE_INT16));
1011   scm_define (sym_uint32, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32));
1012   scm_define (sym_int32, scm_from_uint8 (SCM_FOREIGN_TYPE_INT32));
1013   scm_define (sym_uint64, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64));
1014   scm_define (sym_int64, scm_from_uint8 (SCM_FOREIGN_TYPE_INT64));
1015
1016   scm_define (sym_int,
1017 #if SIZEOF_INT == 8
1018               scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
1019 #elif SIZEOF_INT == 4
1020               scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)
1021 #else
1022 # error unsupported sizeof (int)
1023 #endif
1024               );
1025
1026   scm_define (sym_unsigned_int,
1027 #if SIZEOF_UNSIGNED_INT == 8
1028               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
1029 #elif SIZEOF_UNSIGNED_INT == 4
1030               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
1031 #else
1032 # error unsupported sizeof (unsigned int)
1033 #endif
1034               );
1035
1036   scm_define (sym_long,
1037 #if SIZEOF_LONG == 8
1038               scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)
1039 #elif SIZEOF_LONG == 4
1040               scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)
1041 #else
1042 # error unsupported sizeof (long)
1043 #endif
1044               );
1045
1046   scm_define (sym_unsigned_long,
1047 #if SIZEOF_UNSIGNED_LONG == 8
1048               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
1049 #elif SIZEOF_UNSIGNED_LONG == 4
1050               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
1051 #else
1052 # error unsupported sizeof (unsigned long)
1053 #endif
1054               );
1055
1056   scm_define (sym_size_t,
1057 #if SIZEOF_SIZE_T == 8
1058               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)
1059 #elif SIZEOF_SIZE_T == 4
1060               scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)
1061 #else
1062 # error unsupported sizeof (size_t)
1063 #endif
1064               );
1065
1066   scm_define (sym_null, PTR2SCM (&null_pointer));
1067 }
1068
1069 void
1070 scm_register_foreign (void)
1071 {
1072   scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
1073                             "scm_init_foreign",
1074                             (scm_t_extension_init_func)scm_init_foreign,
1075                             NULL);
1076   foreign_weak_refs = scm_make_weak_key_hash_table (SCM_UNDEFINED);
1077 }
1078
1079 /*
1080   Local Variables:
1081   c-file-style: "gnu"
1082   End:
1083 */