| 1 | /* Copyright (C) 2010-2013 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 <alloca.h> |
| 26 | #include <alignof.h> |
| 27 | #include <string.h> |
| 28 | #include <assert.h> |
| 29 | |
| 30 | #include "libguile/_scm.h" |
| 31 | #include "libguile/bytevectors.h" |
| 32 | #include "libguile/instructions.h" |
| 33 | #include "libguile/threads.h" |
| 34 | #include "libguile/foreign.h" |
| 35 | |
| 36 | \f |
| 37 | |
| 38 | SCM_SYMBOL (sym_void, "void"); |
| 39 | SCM_SYMBOL (sym_float, "float"); |
| 40 | SCM_SYMBOL (sym_double, "double"); |
| 41 | SCM_SYMBOL (sym_uint8, "uint8"); |
| 42 | SCM_SYMBOL (sym_int8, "int8"); |
| 43 | SCM_SYMBOL (sym_uint16, "uint16"); |
| 44 | SCM_SYMBOL (sym_int16, "int16"); |
| 45 | SCM_SYMBOL (sym_uint32, "uint32"); |
| 46 | SCM_SYMBOL (sym_int32, "int32"); |
| 47 | SCM_SYMBOL (sym_uint64, "uint64"); |
| 48 | SCM_SYMBOL (sym_int64, "int64"); |
| 49 | SCM_SYMBOL (sym_short, "short"); |
| 50 | SCM_SYMBOL (sym_int, "int"); |
| 51 | SCM_SYMBOL (sym_long, "long"); |
| 52 | SCM_SYMBOL (sym_unsigned_short, "unsigned-short"); |
| 53 | SCM_SYMBOL (sym_unsigned_int, "unsigned-int"); |
| 54 | SCM_SYMBOL (sym_unsigned_long, "unsigned-long"); |
| 55 | SCM_SYMBOL (sym_size_t, "size_t"); |
| 56 | SCM_SYMBOL (sym_ssize_t, "ssize_t"); |
| 57 | SCM_SYMBOL (sym_ptrdiff_t, "ptrdiff_t"); |
| 58 | |
| 59 | /* that's for pointers, you know. */ |
| 60 | SCM_SYMBOL (sym_asterisk, "*"); |
| 61 | |
| 62 | SCM_SYMBOL (sym_null, "%null-pointer"); |
| 63 | SCM_SYMBOL (sym_null_pointer_error, "null-pointer-error"); |
| 64 | |
| 65 | /* The cell representing the null pointer. */ |
| 66 | static SCM null_pointer; |
| 67 | |
| 68 | |
| 69 | /* Raise a null pointer dereference error. */ |
| 70 | static void |
| 71 | null_pointer_error (const char *func_name) |
| 72 | { |
| 73 | scm_error (sym_null_pointer_error, func_name, |
| 74 | "null pointer dereference", SCM_EOL, SCM_EOL); |
| 75 | } |
| 76 | |
| 77 | \f |
| 78 | static SCM cif_to_procedure (SCM cif, SCM func_ptr); |
| 79 | |
| 80 | |
| 81 | static SCM pointer_weak_refs = SCM_BOOL_F; |
| 82 | |
| 83 | |
| 84 | static void |
| 85 | register_weak_reference (SCM from, SCM to) |
| 86 | { |
| 87 | scm_weak_table_putq_x (pointer_weak_refs, from, to); |
| 88 | } |
| 89 | |
| 90 | static void |
| 91 | pointer_finalizer_trampoline (void *ptr, void *data) |
| 92 | { |
| 93 | scm_t_pointer_finalizer finalizer = data; |
| 94 | finalizer (SCM_POINTER_VALUE (SCM_PACK_POINTER (ptr))); |
| 95 | } |
| 96 | |
| 97 | SCM_DEFINE (scm_pointer_p, "pointer?", 1, 0, 0, |
| 98 | (SCM obj), |
| 99 | "Return @code{#t} if @var{obj} is a pointer object, " |
| 100 | "@code{#f} otherwise.\n") |
| 101 | #define FUNC_NAME s_scm_pointer_p |
| 102 | { |
| 103 | return scm_from_bool (SCM_POINTER_P (obj)); |
| 104 | } |
| 105 | #undef FUNC_NAME |
| 106 | |
| 107 | SCM_DEFINE (scm_make_pointer, "make-pointer", 1, 1, 0, |
| 108 | (SCM address, SCM finalizer), |
| 109 | "Return a foreign pointer object pointing to @var{address}. " |
| 110 | "If @var{finalizer} is passed, it should be a pointer to a " |
| 111 | "one-argument C function that will be called when the pointer " |
| 112 | "object becomes unreachable.") |
| 113 | #define FUNC_NAME s_scm_make_pointer |
| 114 | { |
| 115 | void *c_finalizer; |
| 116 | scm_t_uintptr c_address; |
| 117 | |
| 118 | c_address = scm_to_uintptr_t (address); |
| 119 | if (SCM_UNBNDP (finalizer)) |
| 120 | c_finalizer = NULL; |
| 121 | else |
| 122 | { |
| 123 | SCM_VALIDATE_POINTER (2, finalizer); |
| 124 | c_finalizer = SCM_POINTER_VALUE (finalizer); |
| 125 | } |
| 126 | |
| 127 | return scm_from_pointer ((void *) c_address, c_finalizer); |
| 128 | } |
| 129 | #undef FUNC_NAME |
| 130 | |
| 131 | void * |
| 132 | scm_to_pointer (SCM pointer) |
| 133 | #define FUNC_NAME "scm_to_pointer" |
| 134 | { |
| 135 | SCM_VALIDATE_POINTER (1, pointer); |
| 136 | return SCM_POINTER_VALUE (pointer); |
| 137 | } |
| 138 | #undef FUNC_NAME |
| 139 | |
| 140 | SCM |
| 141 | scm_from_pointer (void *ptr, scm_t_pointer_finalizer finalizer) |
| 142 | { |
| 143 | SCM ret; |
| 144 | |
| 145 | if (ptr == NULL && finalizer == NULL) |
| 146 | ret = null_pointer; |
| 147 | else |
| 148 | { |
| 149 | ret = scm_cell (scm_tc7_pointer, (scm_t_bits) ptr); |
| 150 | |
| 151 | if (finalizer) |
| 152 | scm_i_set_finalizer (SCM2PTR (ret), pointer_finalizer_trampoline, |
| 153 | finalizer); |
| 154 | } |
| 155 | |
| 156 | return ret; |
| 157 | } |
| 158 | |
| 159 | SCM_DEFINE (scm_pointer_address, "pointer-address", 1, 0, 0, |
| 160 | (SCM pointer), |
| 161 | "Return the numerical value of @var{pointer}.") |
| 162 | #define FUNC_NAME s_scm_pointer_address |
| 163 | { |
| 164 | SCM_VALIDATE_POINTER (1, pointer); |
| 165 | |
| 166 | return scm_from_uintptr_t ((scm_t_uintptr) SCM_POINTER_VALUE (pointer)); |
| 167 | } |
| 168 | #undef FUNC_NAME |
| 169 | |
| 170 | SCM_DEFINE (scm_pointer_to_scm, "pointer->scm", 1, 0, 0, |
| 171 | (SCM pointer), |
| 172 | "Unsafely cast @var{pointer} to a Scheme object.\n" |
| 173 | "Cross your fingers!") |
| 174 | #define FUNC_NAME s_scm_pointer_to_scm |
| 175 | { |
| 176 | SCM_VALIDATE_POINTER (1, pointer); |
| 177 | |
| 178 | return SCM_PACK ((scm_t_bits) SCM_POINTER_VALUE (pointer)); |
| 179 | } |
| 180 | #undef FUNC_NAME |
| 181 | |
| 182 | SCM_DEFINE (scm_scm_to_pointer, "scm->pointer", 1, 0, 0, |
| 183 | (SCM scm), |
| 184 | "Return a foreign pointer object with the @code{object-address}\n" |
| 185 | "of @var{scm}.") |
| 186 | #define FUNC_NAME s_scm_scm_to_pointer |
| 187 | { |
| 188 | SCM ret; |
| 189 | |
| 190 | ret = scm_from_pointer ((void*) SCM_UNPACK (scm), NULL); |
| 191 | if (SCM_HEAP_OBJECT_P (ret)) |
| 192 | register_weak_reference (ret, scm); |
| 193 | |
| 194 | return ret; |
| 195 | } |
| 196 | #undef FUNC_NAME |
| 197 | |
| 198 | SCM_DEFINE (scm_pointer_to_bytevector, "pointer->bytevector", 2, 2, 0, |
| 199 | (SCM pointer, SCM len, SCM offset, SCM uvec_type), |
| 200 | "Return a bytevector aliasing the @var{len} bytes pointed\n" |
| 201 | "to by @var{pointer}.\n\n" |
| 202 | "The user may specify an alternate default interpretation for\n" |
| 203 | "the memory by passing the @var{uvec_type} argument, to indicate\n" |
| 204 | "that the memory is an array of elements of that type.\n" |
| 205 | "@var{uvec_type} should be something that\n" |
| 206 | "@code{uniform-vector-element-type} would return, like @code{f32}\n" |
| 207 | "or @code{s16}.\n\n" |
| 208 | "When @var{offset} is passed, it specifies the offset in bytes\n" |
| 209 | "relative to @var{pointer} of the memory region aliased by the\n" |
| 210 | "returned bytevector.") |
| 211 | #define FUNC_NAME s_scm_pointer_to_bytevector |
| 212 | { |
| 213 | SCM ret; |
| 214 | scm_t_int8 *ptr; |
| 215 | size_t boffset, blen; |
| 216 | scm_t_array_element_type btype; |
| 217 | |
| 218 | SCM_VALIDATE_POINTER (1, pointer); |
| 219 | ptr = SCM_POINTER_VALUE (pointer); |
| 220 | |
| 221 | if (SCM_UNLIKELY (ptr == NULL)) |
| 222 | null_pointer_error (FUNC_NAME); |
| 223 | |
| 224 | if (SCM_UNBNDP (uvec_type)) |
| 225 | btype = SCM_ARRAY_ELEMENT_TYPE_VU8; |
| 226 | else |
| 227 | { |
| 228 | int i; |
| 229 | for (i = 0; i <= SCM_ARRAY_ELEMENT_TYPE_LAST; i++) |
| 230 | if (scm_is_eq (uvec_type, scm_i_array_element_types[i])) |
| 231 | break; |
| 232 | switch (i) |
| 233 | { |
| 234 | case SCM_ARRAY_ELEMENT_TYPE_VU8: |
| 235 | case SCM_ARRAY_ELEMENT_TYPE_U8: |
| 236 | case SCM_ARRAY_ELEMENT_TYPE_S8: |
| 237 | case SCM_ARRAY_ELEMENT_TYPE_U16: |
| 238 | case SCM_ARRAY_ELEMENT_TYPE_S16: |
| 239 | case SCM_ARRAY_ELEMENT_TYPE_U32: |
| 240 | case SCM_ARRAY_ELEMENT_TYPE_S32: |
| 241 | case SCM_ARRAY_ELEMENT_TYPE_U64: |
| 242 | case SCM_ARRAY_ELEMENT_TYPE_S64: |
| 243 | case SCM_ARRAY_ELEMENT_TYPE_F32: |
| 244 | case SCM_ARRAY_ELEMENT_TYPE_F64: |
| 245 | case SCM_ARRAY_ELEMENT_TYPE_C32: |
| 246 | case SCM_ARRAY_ELEMENT_TYPE_C64: |
| 247 | btype = i; |
| 248 | break; |
| 249 | default: |
| 250 | scm_wrong_type_arg_msg (FUNC_NAME, SCM_ARG1, uvec_type, |
| 251 | "uniform vector type"); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | if (SCM_UNBNDP (offset)) |
| 256 | boffset = 0; |
| 257 | else |
| 258 | boffset = scm_to_size_t (offset); |
| 259 | |
| 260 | blen = scm_to_size_t (len); |
| 261 | |
| 262 | ret = scm_c_take_typed_bytevector ((signed char *) ptr + boffset, |
| 263 | blen, btype, pointer); |
| 264 | |
| 265 | return ret; |
| 266 | } |
| 267 | #undef FUNC_NAME |
| 268 | |
| 269 | SCM_DEFINE (scm_bytevector_to_pointer, "bytevector->pointer", 1, 1, 0, |
| 270 | (SCM bv, SCM offset), |
| 271 | "Return a pointer pointer aliasing the memory pointed to by\n" |
| 272 | "@var{bv} or @var{offset} bytes after @var{bv} when @var{offset}\n" |
| 273 | "is passed.") |
| 274 | #define FUNC_NAME s_scm_bytevector_to_pointer |
| 275 | { |
| 276 | SCM ret; |
| 277 | signed char *ptr; |
| 278 | size_t boffset; |
| 279 | |
| 280 | SCM_VALIDATE_BYTEVECTOR (1, bv); |
| 281 | ptr = SCM_BYTEVECTOR_CONTENTS (bv); |
| 282 | |
| 283 | if (SCM_UNBNDP (offset)) |
| 284 | boffset = 0; |
| 285 | else |
| 286 | boffset = scm_to_unsigned_integer (offset, 0, |
| 287 | SCM_BYTEVECTOR_LENGTH (bv) - 1); |
| 288 | |
| 289 | ret = scm_from_pointer (ptr + boffset, NULL); |
| 290 | register_weak_reference (ret, bv); |
| 291 | return ret; |
| 292 | } |
| 293 | #undef FUNC_NAME |
| 294 | |
| 295 | SCM_DEFINE (scm_set_pointer_finalizer_x, "set-pointer-finalizer!", 2, 0, 0, |
| 296 | (SCM pointer, SCM finalizer), |
| 297 | "Arrange for the C procedure wrapped by @var{finalizer} to be\n" |
| 298 | "called on the pointer wrapped by @var{pointer} when @var{pointer}\n" |
| 299 | "becomes unreachable. Note: the C procedure should not call into\n" |
| 300 | "Scheme. If you need a Scheme finalizer, use guardians.") |
| 301 | #define FUNC_NAME s_scm_set_pointer_finalizer_x |
| 302 | { |
| 303 | SCM_VALIDATE_POINTER (1, pointer); |
| 304 | SCM_VALIDATE_POINTER (2, finalizer); |
| 305 | |
| 306 | scm_i_add_finalizer (SCM2PTR (pointer), pointer_finalizer_trampoline, |
| 307 | SCM_POINTER_VALUE (finalizer)); |
| 308 | |
| 309 | return SCM_UNSPECIFIED; |
| 310 | } |
| 311 | #undef FUNC_NAME |
| 312 | |
| 313 | void |
| 314 | scm_i_pointer_print (SCM pointer, SCM port, scm_print_state *pstate) |
| 315 | { |
| 316 | scm_puts_unlocked ("#<pointer 0x", port); |
| 317 | scm_uintprint (scm_to_uintptr_t (scm_pointer_address (pointer)), 16, port); |
| 318 | scm_putc_unlocked ('>', port); |
| 319 | } |
| 320 | |
| 321 | \f |
| 322 | /* Non-primitive helpers functions. These procedures could be |
| 323 | implemented in terms of the primitives above but would be inefficient |
| 324 | (heap allocation overhead, Scheme/C round trips, etc.) */ |
| 325 | |
| 326 | SCM_DEFINE (scm_dereference_pointer, "dereference-pointer", 1, 0, 0, |
| 327 | (SCM pointer), |
| 328 | "Assuming @var{pointer} points to a memory region that\n" |
| 329 | "holds a pointer, return this pointer.") |
| 330 | #define FUNC_NAME s_scm_dereference_pointer |
| 331 | { |
| 332 | void **ptr; |
| 333 | |
| 334 | SCM_VALIDATE_POINTER (1, pointer); |
| 335 | |
| 336 | ptr = SCM_POINTER_VALUE (pointer); |
| 337 | if (SCM_UNLIKELY (ptr == NULL)) |
| 338 | null_pointer_error (FUNC_NAME); |
| 339 | |
| 340 | return scm_from_pointer (*ptr, NULL); |
| 341 | } |
| 342 | #undef FUNC_NAME |
| 343 | |
| 344 | SCM_DEFINE (scm_string_to_pointer, "string->pointer", 1, 1, 0, |
| 345 | (SCM string, SCM encoding), |
| 346 | "Return a foreign pointer to a nul-terminated copy of\n" |
| 347 | "@var{string} in the given @var{encoding}, defaulting to\n" |
| 348 | "the current locale encoding. The C string is freed when\n" |
| 349 | "the returned foreign pointer becomes unreachable.\n\n" |
| 350 | "This is the Scheme equivalent of @code{scm_to_stringn}.") |
| 351 | #define FUNC_NAME s_scm_string_to_pointer |
| 352 | { |
| 353 | SCM_VALIDATE_STRING (1, string); |
| 354 | |
| 355 | /* XXX: Finalizers slow down libgc; they could be avoided if |
| 356 | `scm_to_string' & co. were able to use libgc-allocated memory. */ |
| 357 | |
| 358 | if (SCM_UNBNDP (encoding)) |
| 359 | return scm_from_pointer (scm_to_locale_string (string), free); |
| 360 | else |
| 361 | { |
| 362 | char *enc; |
| 363 | SCM ret; |
| 364 | |
| 365 | SCM_VALIDATE_STRING (2, encoding); |
| 366 | |
| 367 | enc = scm_to_locale_string (encoding); |
| 368 | scm_dynwind_begin (0); |
| 369 | scm_dynwind_free (enc); |
| 370 | |
| 371 | ret = scm_from_pointer |
| 372 | (scm_to_stringn (string, NULL, enc, |
| 373 | scm_i_default_port_conversion_handler ()), |
| 374 | free); |
| 375 | |
| 376 | scm_dynwind_end (); |
| 377 | |
| 378 | return ret; |
| 379 | } |
| 380 | } |
| 381 | #undef FUNC_NAME |
| 382 | |
| 383 | SCM_DEFINE (scm_pointer_to_string, "pointer->string", 1, 2, 0, |
| 384 | (SCM pointer, SCM length, SCM encoding), |
| 385 | "Return the string representing the C string pointed to by\n" |
| 386 | "@var{pointer}. If @var{length} is omitted or @code{-1}, the\n" |
| 387 | "string is assumed to be nul-terminated. Otherwise\n" |
| 388 | "@var{length} is the number of bytes in memory pointed to by\n" |
| 389 | "@var{pointer}. The C string is assumed to be in the given\n" |
| 390 | "@var{encoding}, defaulting to the current locale encoding.\n\n" |
| 391 | "This is the Scheme equivalent of @code{scm_from_stringn}.") |
| 392 | #define FUNC_NAME s_scm_pointer_to_string |
| 393 | { |
| 394 | size_t len; |
| 395 | |
| 396 | SCM_VALIDATE_POINTER (1, pointer); |
| 397 | |
| 398 | if (SCM_UNBNDP (length) |
| 399 | || scm_is_true (scm_eqv_p (length, scm_from_int (-1)))) |
| 400 | len = (size_t)-1; |
| 401 | else |
| 402 | len = scm_to_size_t (length); |
| 403 | |
| 404 | if (SCM_UNBNDP (encoding)) |
| 405 | return scm_from_locale_stringn (SCM_POINTER_VALUE (pointer), len); |
| 406 | else |
| 407 | { |
| 408 | char *enc; |
| 409 | SCM ret; |
| 410 | |
| 411 | SCM_VALIDATE_STRING (3, encoding); |
| 412 | |
| 413 | enc = scm_to_locale_string (encoding); |
| 414 | scm_dynwind_begin (0); |
| 415 | scm_dynwind_free (enc); |
| 416 | |
| 417 | ret = scm_from_stringn (SCM_POINTER_VALUE (pointer), len, enc, |
| 418 | scm_i_default_port_conversion_handler ()); |
| 419 | |
| 420 | scm_dynwind_end (); |
| 421 | |
| 422 | return ret; |
| 423 | } |
| 424 | } |
| 425 | #undef FUNC_NAME |
| 426 | |
| 427 | \f |
| 428 | |
| 429 | SCM_DEFINE (scm_alignof, "alignof", 1, 0, 0, (SCM type), |
| 430 | "Return the alignment of @var{type}, in bytes.\n\n" |
| 431 | "@var{type} should be a valid C type, like @code{int}.\n" |
| 432 | "Alternately @var{type} may be the symbol @code{*}, in which\n" |
| 433 | "case the alignment of a pointer is returned. @var{type} may\n" |
| 434 | "also be a list of types, in which case the alignment of a\n" |
| 435 | "@code{struct} with ABI-conventional packing is returned.") |
| 436 | #define FUNC_NAME s_scm_alignof |
| 437 | { |
| 438 | if (SCM_I_INUMP (type)) |
| 439 | { |
| 440 | switch (SCM_I_INUM (type)) |
| 441 | { |
| 442 | case SCM_FOREIGN_TYPE_FLOAT: |
| 443 | return scm_from_size_t (alignof_type (float)); |
| 444 | case SCM_FOREIGN_TYPE_DOUBLE: |
| 445 | return scm_from_size_t (alignof_type (double)); |
| 446 | case SCM_FOREIGN_TYPE_UINT8: |
| 447 | return scm_from_size_t (alignof_type (scm_t_uint8)); |
| 448 | case SCM_FOREIGN_TYPE_INT8: |
| 449 | return scm_from_size_t (alignof_type (scm_t_int8)); |
| 450 | case SCM_FOREIGN_TYPE_UINT16: |
| 451 | return scm_from_size_t (alignof_type (scm_t_uint16)); |
| 452 | case SCM_FOREIGN_TYPE_INT16: |
| 453 | return scm_from_size_t (alignof_type (scm_t_int16)); |
| 454 | case SCM_FOREIGN_TYPE_UINT32: |
| 455 | return scm_from_size_t (alignof_type (scm_t_uint32)); |
| 456 | case SCM_FOREIGN_TYPE_INT32: |
| 457 | return scm_from_size_t (alignof_type (scm_t_int32)); |
| 458 | case SCM_FOREIGN_TYPE_UINT64: |
| 459 | return scm_from_size_t (alignof_type (scm_t_uint64)); |
| 460 | case SCM_FOREIGN_TYPE_INT64: |
| 461 | return scm_from_size_t (alignof_type (scm_t_int64)); |
| 462 | default: |
| 463 | scm_wrong_type_arg (FUNC_NAME, 1, type); |
| 464 | } |
| 465 | } |
| 466 | else if (scm_is_eq (type, sym_asterisk)) |
| 467 | /* a pointer */ |
| 468 | return scm_from_size_t (alignof_type (void*)); |
| 469 | else if (scm_is_pair (type)) |
| 470 | { |
| 471 | /* TYPE is a structure. Section 3-3 of the i386, x86_64, PowerPC, |
| 472 | and SPARC P.S. of the System V ABI all say: "Aggregates |
| 473 | (structures and arrays) and unions assume the alignment of |
| 474 | their most strictly aligned component." */ |
| 475 | size_t max; |
| 476 | |
| 477 | for (max = 0; scm_is_pair (type); type = SCM_CDR (type)) |
| 478 | { |
| 479 | size_t align; |
| 480 | |
| 481 | align = scm_to_size_t (scm_alignof (SCM_CAR (type))); |
| 482 | if (align > max) |
| 483 | max = align; |
| 484 | } |
| 485 | |
| 486 | return scm_from_size_t (max); |
| 487 | } |
| 488 | else |
| 489 | scm_wrong_type_arg (FUNC_NAME, 1, type); |
| 490 | } |
| 491 | #undef FUNC_NAME |
| 492 | |
| 493 | SCM_DEFINE (scm_sizeof, "sizeof", 1, 0, 0, (SCM type), |
| 494 | "Return the size of @var{type}, in bytes.\n\n" |
| 495 | "@var{type} should be a valid C type, like @code{int}.\n" |
| 496 | "Alternately @var{type} may be the symbol @code{*}, in which\n" |
| 497 | "case the size of a pointer is returned. @var{type} may also\n" |
| 498 | "be a list of types, in which case the size of a @code{struct}\n" |
| 499 | "with ABI-conventional packing is returned.") |
| 500 | #define FUNC_NAME s_scm_sizeof |
| 501 | { |
| 502 | if (SCM_I_INUMP (type)) |
| 503 | { |
| 504 | switch (SCM_I_INUM (type)) |
| 505 | { |
| 506 | case SCM_FOREIGN_TYPE_FLOAT: |
| 507 | return scm_from_size_t (sizeof (float)); |
| 508 | case SCM_FOREIGN_TYPE_DOUBLE: |
| 509 | return scm_from_size_t (sizeof (double)); |
| 510 | case SCM_FOREIGN_TYPE_UINT8: |
| 511 | return scm_from_size_t (sizeof (scm_t_uint8)); |
| 512 | case SCM_FOREIGN_TYPE_INT8: |
| 513 | return scm_from_size_t (sizeof (scm_t_int8)); |
| 514 | case SCM_FOREIGN_TYPE_UINT16: |
| 515 | return scm_from_size_t (sizeof (scm_t_uint16)); |
| 516 | case SCM_FOREIGN_TYPE_INT16: |
| 517 | return scm_from_size_t (sizeof (scm_t_int16)); |
| 518 | case SCM_FOREIGN_TYPE_UINT32: |
| 519 | return scm_from_size_t (sizeof (scm_t_uint32)); |
| 520 | case SCM_FOREIGN_TYPE_INT32: |
| 521 | return scm_from_size_t (sizeof (scm_t_int32)); |
| 522 | case SCM_FOREIGN_TYPE_UINT64: |
| 523 | return scm_from_size_t (sizeof (scm_t_uint64)); |
| 524 | case SCM_FOREIGN_TYPE_INT64: |
| 525 | return scm_from_size_t (sizeof (scm_t_int64)); |
| 526 | default: |
| 527 | scm_wrong_type_arg (FUNC_NAME, 1, type); |
| 528 | } |
| 529 | } |
| 530 | else if (scm_is_eq (type, sym_asterisk)) |
| 531 | /* a pointer */ |
| 532 | return scm_from_size_t (sizeof (void*)); |
| 533 | else if (scm_is_pair (type)) |
| 534 | { |
| 535 | /* a struct */ |
| 536 | size_t off = 0; |
| 537 | size_t align = scm_to_size_t (scm_alignof(type)); |
| 538 | while (scm_is_pair (type)) |
| 539 | { |
| 540 | off = ROUND_UP (off, scm_to_size_t (scm_alignof (scm_car (type)))); |
| 541 | off += scm_to_size_t (scm_sizeof (scm_car (type))); |
| 542 | type = scm_cdr (type); |
| 543 | } |
| 544 | return scm_from_size_t (ROUND_UP(off, align)); |
| 545 | } |
| 546 | else |
| 547 | scm_wrong_type_arg (FUNC_NAME, 1, type); |
| 548 | } |
| 549 | #undef FUNC_NAME |
| 550 | |
| 551 | |
| 552 | /* return 1 on success, 0 on failure */ |
| 553 | static int |
| 554 | parse_ffi_type (SCM type, int return_p, long *n_structs, long *n_struct_elts) |
| 555 | { |
| 556 | if (SCM_I_INUMP (type)) |
| 557 | { |
| 558 | if ((SCM_I_INUM (type) < 0 ) |
| 559 | || (SCM_I_INUM (type) > SCM_FOREIGN_TYPE_LAST)) |
| 560 | return 0; |
| 561 | else if (SCM_I_INUM (type) == SCM_FOREIGN_TYPE_VOID && !return_p) |
| 562 | return 0; |
| 563 | else |
| 564 | return 1; |
| 565 | } |
| 566 | else if (scm_is_eq (type, sym_asterisk)) |
| 567 | /* a pointer */ |
| 568 | return 1; |
| 569 | else |
| 570 | { |
| 571 | long len; |
| 572 | |
| 573 | len = scm_ilength (type); |
| 574 | if (len < 1) |
| 575 | return 0; |
| 576 | while (len--) |
| 577 | { |
| 578 | if (!parse_ffi_type (scm_car (type), 0, n_structs, n_struct_elts)) |
| 579 | return 0; |
| 580 | (*n_struct_elts)++; |
| 581 | type = scm_cdr (type); |
| 582 | } |
| 583 | (*n_structs)++; |
| 584 | return 1; |
| 585 | } |
| 586 | } |
| 587 | |
| 588 | static void |
| 589 | fill_ffi_type (SCM type, ffi_type *ftype, ffi_type ***type_ptrs, |
| 590 | ffi_type **types) |
| 591 | { |
| 592 | if (SCM_I_INUMP (type)) |
| 593 | { |
| 594 | switch (SCM_I_INUM (type)) |
| 595 | { |
| 596 | case SCM_FOREIGN_TYPE_FLOAT: |
| 597 | *ftype = ffi_type_float; |
| 598 | return; |
| 599 | case SCM_FOREIGN_TYPE_DOUBLE: |
| 600 | *ftype = ffi_type_double; |
| 601 | return; |
| 602 | case SCM_FOREIGN_TYPE_UINT8: |
| 603 | *ftype = ffi_type_uint8; |
| 604 | return; |
| 605 | case SCM_FOREIGN_TYPE_INT8: |
| 606 | *ftype = ffi_type_sint8; |
| 607 | return; |
| 608 | case SCM_FOREIGN_TYPE_UINT16: |
| 609 | *ftype = ffi_type_uint16; |
| 610 | return; |
| 611 | case SCM_FOREIGN_TYPE_INT16: |
| 612 | *ftype = ffi_type_sint16; |
| 613 | return; |
| 614 | case SCM_FOREIGN_TYPE_UINT32: |
| 615 | *ftype = ffi_type_uint32; |
| 616 | return; |
| 617 | case SCM_FOREIGN_TYPE_INT32: |
| 618 | *ftype = ffi_type_sint32; |
| 619 | return; |
| 620 | case SCM_FOREIGN_TYPE_UINT64: |
| 621 | *ftype = ffi_type_uint64; |
| 622 | return; |
| 623 | case SCM_FOREIGN_TYPE_INT64: |
| 624 | *ftype = ffi_type_sint64; |
| 625 | return; |
| 626 | case SCM_FOREIGN_TYPE_VOID: |
| 627 | *ftype = ffi_type_void; |
| 628 | return; |
| 629 | default: |
| 630 | scm_wrong_type_arg_msg ("pointer->procedure", 0, type, |
| 631 | "foreign type"); |
| 632 | } |
| 633 | } |
| 634 | else if (scm_is_eq (type, sym_asterisk)) |
| 635 | /* a pointer */ |
| 636 | { |
| 637 | *ftype = ffi_type_pointer; |
| 638 | return; |
| 639 | } |
| 640 | else |
| 641 | { |
| 642 | long i, len; |
| 643 | |
| 644 | len = scm_ilength (type); |
| 645 | |
| 646 | ftype->size = 0; |
| 647 | ftype->alignment = 0; |
| 648 | ftype->type = FFI_TYPE_STRUCT; |
| 649 | ftype->elements = *type_ptrs; |
| 650 | *type_ptrs += len + 1; |
| 651 | |
| 652 | for (i = 0; i < len; i++) |
| 653 | { |
| 654 | ftype->elements[i] = *types; |
| 655 | *types += 1; |
| 656 | fill_ffi_type (scm_car (type), ftype->elements[i], |
| 657 | type_ptrs, types); |
| 658 | type = scm_cdr (type); |
| 659 | } |
| 660 | ftype->elements[i] = NULL; |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | /* Return a "cif" (call interface) for the given RETURN_TYPE and |
| 665 | ARG_TYPES. */ |
| 666 | static ffi_cif * |
| 667 | make_cif (SCM return_type, SCM arg_types, const char *caller) |
| 668 | #define FUNC_NAME caller |
| 669 | { |
| 670 | SCM walk; |
| 671 | long i, nargs, n_structs, n_struct_elts; |
| 672 | size_t cif_len; |
| 673 | char *mem; |
| 674 | ffi_cif *cif; |
| 675 | ffi_type **type_ptrs; |
| 676 | ffi_type *types; |
| 677 | |
| 678 | nargs = scm_ilength (arg_types); |
| 679 | SCM_ASSERT (nargs >= 0, arg_types, 3, FUNC_NAME); |
| 680 | /* fixme: assert nargs < 1<<32 */ |
| 681 | n_structs = n_struct_elts = 0; |
| 682 | |
| 683 | /* For want of talloc, we're going to have to do this in two passes: first we |
| 684 | figure out how much memory is needed for all types, then we allocate the |
| 685 | cif and the types all in one block. */ |
| 686 | if (!parse_ffi_type (return_type, 1, &n_structs, &n_struct_elts)) |
| 687 | scm_wrong_type_arg (FUNC_NAME, 1, return_type); |
| 688 | for (walk = arg_types; scm_is_pair (walk); walk = scm_cdr (walk)) |
| 689 | if (!parse_ffi_type (scm_car (walk), 0, &n_structs, &n_struct_elts)) |
| 690 | scm_wrong_type_arg (FUNC_NAME, 3, scm_car (walk)); |
| 691 | |
| 692 | /* the memory: with space for the cif itself */ |
| 693 | cif_len = sizeof (ffi_cif); |
| 694 | |
| 695 | /* then ffi_type pointers: one for each arg, one for each struct |
| 696 | element, and one for each struct (for null-termination) */ |
| 697 | cif_len = (ROUND_UP (cif_len, alignof_type (void *)) |
| 698 | + (nargs + n_structs + n_struct_elts)*sizeof(void*)); |
| 699 | |
| 700 | /* then the ffi_type structs themselves, one per arg and struct element, and |
| 701 | one for the return val */ |
| 702 | cif_len = (ROUND_UP (cif_len, alignof_type (ffi_type)) |
| 703 | + (nargs + n_struct_elts + 1)*sizeof(ffi_type)); |
| 704 | |
| 705 | mem = scm_gc_malloc_pointerless (cif_len, "foreign"); |
| 706 | /* ensure all the memory is initialized, even the holes */ |
| 707 | memset (mem, 0, cif_len); |
| 708 | cif = (ffi_cif *) mem; |
| 709 | |
| 710 | /* reuse cif_len to walk through the mem */ |
| 711 | cif_len = ROUND_UP (sizeof (ffi_cif), alignof_type (void *)); |
| 712 | type_ptrs = (ffi_type**)(mem + cif_len); |
| 713 | cif_len = ROUND_UP (cif_len |
| 714 | + (nargs + n_structs + n_struct_elts)*sizeof(void*), |
| 715 | alignof_type (ffi_type)); |
| 716 | types = (ffi_type*)(mem + cif_len); |
| 717 | |
| 718 | /* whew. now knit the pointers together. */ |
| 719 | cif->rtype = types++; |
| 720 | fill_ffi_type (return_type, cif->rtype, &type_ptrs, &types); |
| 721 | cif->arg_types = type_ptrs; |
| 722 | type_ptrs += nargs; |
| 723 | for (walk = arg_types, i = 0; scm_is_pair (walk); walk = scm_cdr (walk), i++) |
| 724 | { |
| 725 | cif->arg_types[i] = types++; |
| 726 | fill_ffi_type (scm_car (walk), cif->arg_types[i], &type_ptrs, &types); |
| 727 | } |
| 728 | |
| 729 | /* round out the cif, and we're done. */ |
| 730 | cif->abi = FFI_DEFAULT_ABI; |
| 731 | cif->nargs = nargs; |
| 732 | cif->bytes = 0; |
| 733 | cif->flags = 0; |
| 734 | |
| 735 | if (FFI_OK != ffi_prep_cif (cif, FFI_DEFAULT_ABI, cif->nargs, cif->rtype, |
| 736 | cif->arg_types)) |
| 737 | SCM_MISC_ERROR ("ffi_prep_cif failed", SCM_EOL); |
| 738 | |
| 739 | return cif; |
| 740 | } |
| 741 | #undef FUNC_NAME |
| 742 | |
| 743 | SCM_DEFINE (scm_pointer_to_procedure, "pointer->procedure", 3, 0, 0, |
| 744 | (SCM return_type, SCM func_ptr, SCM arg_types), |
| 745 | "Make a foreign function.\n\n" |
| 746 | "Given the foreign void pointer @var{func_ptr}, its argument and\n" |
| 747 | "return types @var{arg_types} and @var{return_type}, return a\n" |
| 748 | "procedure that will pass arguments to the foreign function\n" |
| 749 | "and return appropriate values.\n\n" |
| 750 | "@var{arg_types} should be a list of foreign types.\n" |
| 751 | "@code{return_type} should be a foreign type.") |
| 752 | #define FUNC_NAME s_scm_pointer_to_procedure |
| 753 | { |
| 754 | ffi_cif *cif; |
| 755 | |
| 756 | SCM_VALIDATE_POINTER (2, func_ptr); |
| 757 | |
| 758 | cif = make_cif (return_type, arg_types, FUNC_NAME); |
| 759 | |
| 760 | return cif_to_procedure (scm_from_pointer (cif, NULL), func_ptr); |
| 761 | } |
| 762 | #undef FUNC_NAME |
| 763 | |
| 764 | \f |
| 765 | |
| 766 | /* We support calling foreign functions with up to 100 arguments. */ |
| 767 | |
| 768 | #define CODE(nreq) \ |
| 769 | SCM_PACK_OP_24 (assert_nargs_ee, nreq + 1), \ |
| 770 | SCM_PACK_OP_12_12 (foreign_call, 0, 1) |
| 771 | |
| 772 | #define CODE_10(n) \ |
| 773 | CODE (n + 0), CODE (n + 1), CODE (n + 2), CODE (n + 3), CODE (n + 4), \ |
| 774 | CODE (n + 5), CODE (n + 6), CODE (n + 7), CODE (n + 8), CODE (n + 9) |
| 775 | |
| 776 | static const scm_t_uint32 foreign_stub_code[] = |
| 777 | { |
| 778 | CODE_10 (0), CODE_10 (10), CODE_10 (20), CODE_10 (30), CODE_10 (40), |
| 779 | CODE_10 (50), CODE_10 (60), CODE_10 (70), CODE_10 (80), CODE_10 (90) |
| 780 | }; |
| 781 | |
| 782 | #undef CODE |
| 783 | #undef CODE_10 |
| 784 | |
| 785 | static const scm_t_uint32 * |
| 786 | get_foreign_stub_code (unsigned int nargs) |
| 787 | { |
| 788 | if (nargs >= 100) |
| 789 | scm_misc_error ("make-foreign-function", "args >= 100 currently unimplemented", |
| 790 | SCM_EOL); |
| 791 | |
| 792 | return &foreign_stub_code[nargs * 2]; |
| 793 | } |
| 794 | |
| 795 | /* Given a foreign procedure, determine its minimum arity. */ |
| 796 | int |
| 797 | scm_i_foreign_arity (SCM foreign, int *req, int *opt, int *rest) |
| 798 | { |
| 799 | const scm_t_uint32 *code = SCM_PROGRAM_CODE (foreign); |
| 800 | |
| 801 | if (code < foreign_stub_code) |
| 802 | return 0; |
| 803 | if (code > (foreign_stub_code |
| 804 | + (sizeof(foreign_stub_code) / sizeof(scm_t_uint32)))) |
| 805 | return 0; |
| 806 | |
| 807 | *req = (code - foreign_stub_code) / 2; |
| 808 | *opt = 0; |
| 809 | *rest = 0; |
| 810 | |
| 811 | return 1; |
| 812 | } |
| 813 | |
| 814 | static SCM |
| 815 | cif_to_procedure (SCM cif, SCM func_ptr) |
| 816 | { |
| 817 | ffi_cif *c_cif; |
| 818 | SCM ret; |
| 819 | scm_t_bits nfree = 2; |
| 820 | scm_t_bits flags = SCM_F_PROGRAM_IS_FOREIGN; |
| 821 | |
| 822 | c_cif = (ffi_cif *) SCM_POINTER_VALUE (cif); |
| 823 | |
| 824 | ret = scm_words (scm_tc7_program | (nfree << 16) | flags, nfree + 2); |
| 825 | SCM_SET_CELL_WORD_1 (ret, get_foreign_stub_code (c_cif->nargs)); |
| 826 | SCM_PROGRAM_FREE_VARIABLE_SET (ret, 0, cif); |
| 827 | SCM_PROGRAM_FREE_VARIABLE_SET (ret, 1, func_ptr); |
| 828 | |
| 829 | return ret; |
| 830 | } |
| 831 | |
| 832 | /* Set *LOC to the foreign representation of X with TYPE. */ |
| 833 | static void |
| 834 | unpack (const ffi_type *type, void *loc, SCM x, int return_value_p) |
| 835 | #define FUNC_NAME "scm_i_foreign_call" |
| 836 | { |
| 837 | switch (type->type) |
| 838 | { |
| 839 | case FFI_TYPE_FLOAT: |
| 840 | *(float *) loc = scm_to_double (x); |
| 841 | break; |
| 842 | case FFI_TYPE_DOUBLE: |
| 843 | *(double *) loc = scm_to_double (x); |
| 844 | break; |
| 845 | |
| 846 | /* For integer return values smaller than `int', libffi expects the |
| 847 | result in an `ffi_arg'-long buffer. */ |
| 848 | |
| 849 | case FFI_TYPE_UINT8: |
| 850 | if (return_value_p) |
| 851 | *(ffi_arg *) loc = scm_to_uint8 (x); |
| 852 | else |
| 853 | *(scm_t_uint8 *) loc = scm_to_uint8 (x); |
| 854 | break; |
| 855 | case FFI_TYPE_SINT8: |
| 856 | if (return_value_p) |
| 857 | *(ffi_arg *) loc = scm_to_int8 (x); |
| 858 | else |
| 859 | *(scm_t_int8 *) loc = scm_to_int8 (x); |
| 860 | break; |
| 861 | case FFI_TYPE_UINT16: |
| 862 | if (return_value_p) |
| 863 | *(ffi_arg *) loc = scm_to_uint16 (x); |
| 864 | else |
| 865 | *(scm_t_uint16 *) loc = scm_to_uint16 (x); |
| 866 | break; |
| 867 | case FFI_TYPE_SINT16: |
| 868 | if (return_value_p) |
| 869 | *(ffi_arg *) loc = scm_to_int16 (x); |
| 870 | else |
| 871 | *(scm_t_int16 *) loc = scm_to_int16 (x); |
| 872 | break; |
| 873 | case FFI_TYPE_UINT32: |
| 874 | if (return_value_p) |
| 875 | *(ffi_arg *) loc = scm_to_uint32 (x); |
| 876 | else |
| 877 | *(scm_t_uint32 *) loc = scm_to_uint32 (x); |
| 878 | break; |
| 879 | case FFI_TYPE_SINT32: |
| 880 | if (return_value_p) |
| 881 | *(ffi_arg *) loc = scm_to_int32 (x); |
| 882 | else |
| 883 | *(scm_t_int32 *) loc = scm_to_int32 (x); |
| 884 | break; |
| 885 | case FFI_TYPE_UINT64: |
| 886 | *(scm_t_uint64 *) loc = scm_to_uint64 (x); |
| 887 | break; |
| 888 | case FFI_TYPE_SINT64: |
| 889 | *(scm_t_int64 *) loc = scm_to_int64 (x); |
| 890 | break; |
| 891 | case FFI_TYPE_STRUCT: |
| 892 | SCM_VALIDATE_POINTER (1, x); |
| 893 | memcpy (loc, SCM_POINTER_VALUE (x), type->size); |
| 894 | break; |
| 895 | case FFI_TYPE_POINTER: |
| 896 | SCM_VALIDATE_POINTER (1, x); |
| 897 | *(void **) loc = SCM_POINTER_VALUE (x); |
| 898 | break; |
| 899 | case FFI_TYPE_VOID: |
| 900 | /* Do nothing. */ |
| 901 | break; |
| 902 | default: |
| 903 | abort (); |
| 904 | } |
| 905 | } |
| 906 | #undef FUNC_NAME |
| 907 | |
| 908 | /* Return a Scheme representation of the foreign value at LOC of type |
| 909 | TYPE. When RETURN_VALUE_P is true, LOC is assumed to point to a |
| 910 | return value buffer; otherwise LOC is assumed to point to an |
| 911 | argument buffer. */ |
| 912 | static SCM |
| 913 | pack (const ffi_type * type, const void *loc, int return_value_p) |
| 914 | { |
| 915 | switch (type->type) |
| 916 | { |
| 917 | case FFI_TYPE_VOID: |
| 918 | return SCM_UNSPECIFIED; |
| 919 | case FFI_TYPE_FLOAT: |
| 920 | return scm_from_double (*(float *) loc); |
| 921 | case FFI_TYPE_DOUBLE: |
| 922 | return scm_from_double (*(double *) loc); |
| 923 | |
| 924 | /* For integer return values smaller than `int', libffi stores the |
| 925 | result in an `ffi_arg'-long buffer, of which only the |
| 926 | significant bits must be kept---hence the pair of casts below. |
| 927 | See <http://thread.gmane.org/gmane.comp.lib.ffi.general/406> |
| 928 | for details. */ |
| 929 | |
| 930 | case FFI_TYPE_UINT8: |
| 931 | if (return_value_p) |
| 932 | return scm_from_uint8 ((scm_t_uint8) *(ffi_arg *) loc); |
| 933 | else |
| 934 | return scm_from_uint8 (* (scm_t_uint8 *) loc); |
| 935 | case FFI_TYPE_SINT8: |
| 936 | if (return_value_p) |
| 937 | return scm_from_int8 ((scm_t_int8) *(ffi_arg *) loc); |
| 938 | else |
| 939 | return scm_from_int8 (* (scm_t_int8 *) loc); |
| 940 | case FFI_TYPE_UINT16: |
| 941 | if (return_value_p) |
| 942 | return scm_from_uint16 ((scm_t_uint16) *(ffi_arg *) loc); |
| 943 | else |
| 944 | return scm_from_uint16 (* (scm_t_uint16 *) loc); |
| 945 | case FFI_TYPE_SINT16: |
| 946 | if (return_value_p) |
| 947 | return scm_from_int16 ((scm_t_int16) *(ffi_arg *) loc); |
| 948 | else |
| 949 | return scm_from_int16 (* (scm_t_int16 *) loc); |
| 950 | case FFI_TYPE_UINT32: |
| 951 | if (return_value_p) |
| 952 | return scm_from_uint32 ((scm_t_uint32) *(ffi_arg *) loc); |
| 953 | else |
| 954 | return scm_from_uint32 (* (scm_t_uint32 *) loc); |
| 955 | case FFI_TYPE_SINT32: |
| 956 | if (return_value_p) |
| 957 | return scm_from_int32 ((scm_t_int32) *(ffi_arg *) loc); |
| 958 | else |
| 959 | return scm_from_int32 (* (scm_t_int32 *) loc); |
| 960 | case FFI_TYPE_UINT64: |
| 961 | return scm_from_uint64 (*(scm_t_uint64 *) loc); |
| 962 | case FFI_TYPE_SINT64: |
| 963 | return scm_from_int64 (*(scm_t_int64 *) loc); |
| 964 | |
| 965 | case FFI_TYPE_STRUCT: |
| 966 | { |
| 967 | void *mem = scm_gc_malloc_pointerless (type->size, "foreign"); |
| 968 | memcpy (mem, loc, type->size); |
| 969 | return scm_from_pointer (mem, NULL); |
| 970 | } |
| 971 | case FFI_TYPE_POINTER: |
| 972 | return scm_from_pointer (*(void **) loc, NULL); |
| 973 | default: |
| 974 | abort (); |
| 975 | } |
| 976 | } |
| 977 | |
| 978 | |
| 979 | SCM |
| 980 | scm_i_foreign_call (SCM foreign, const SCM *argv) |
| 981 | { |
| 982 | /* FOREIGN is the pair that cif_to_procedure set as the 0th element of the |
| 983 | objtable. */ |
| 984 | ffi_cif *cif; |
| 985 | void (*func) (void); |
| 986 | scm_t_uint8 *data; |
| 987 | void *rvalue; |
| 988 | void **args; |
| 989 | unsigned i; |
| 990 | size_t arg_size; |
| 991 | scm_t_ptrdiff off; |
| 992 | |
| 993 | cif = SCM_POINTER_VALUE (SCM_CAR (foreign)); |
| 994 | func = SCM_POINTER_VALUE (SCM_CDR (foreign)); |
| 995 | |
| 996 | /* Argument pointers. */ |
| 997 | args = alloca (sizeof (void *) * cif->nargs); |
| 998 | |
| 999 | /* Compute the worst-case amount of memory needed to store all the argument |
| 1000 | values. Note: as of libffi 3.0.9 `cif->bytes' is undocumented and is zero, |
| 1001 | so it can't be used for that purpose. */ |
| 1002 | for (i = 0, arg_size = 0; i < cif->nargs; i++) |
| 1003 | arg_size += cif->arg_types[i]->size + cif->arg_types[i]->alignment - 1; |
| 1004 | |
| 1005 | /* Space for argument values, followed by return value. */ |
| 1006 | data = alloca (arg_size + cif->rtype->size |
| 1007 | + max (sizeof (void *), cif->rtype->alignment)); |
| 1008 | |
| 1009 | /* Unpack ARGV to native values, setting ARGV pointers. */ |
| 1010 | for (i = 0, off = 0; |
| 1011 | i < cif->nargs; |
| 1012 | off = (scm_t_uint8 *) args[i] - data + cif->arg_types[i]->size, |
| 1013 | i++) |
| 1014 | { |
| 1015 | /* Suitably align the storage area for argument I. */ |
| 1016 | args[i] = (void *) ROUND_UP ((scm_t_uintptr) data + off, |
| 1017 | cif->arg_types[i]->alignment); |
| 1018 | assert ((scm_t_uintptr) args[i] % cif->arg_types[i]->alignment == 0); |
| 1019 | unpack (cif->arg_types[i], args[i], argv[i], 0); |
| 1020 | } |
| 1021 | |
| 1022 | /* Prepare space for the return value. On some platforms, such as |
| 1023 | `armv5tel-*-linux-gnueabi', the return value has to be at least |
| 1024 | word-aligned, even if its type doesn't have any alignment requirement as is |
| 1025 | the case with `char'. */ |
| 1026 | rvalue = (void *) ROUND_UP ((scm_t_uintptr) data + off, |
| 1027 | max (sizeof (void *), cif->rtype->alignment)); |
| 1028 | |
| 1029 | /* off we go! */ |
| 1030 | ffi_call (cif, func, rvalue, args); |
| 1031 | |
| 1032 | return pack (cif->rtype, rvalue, 1); |
| 1033 | } |
| 1034 | |
| 1035 | \f |
| 1036 | /* Function pointers aka. "callbacks" or "closures". */ |
| 1037 | |
| 1038 | #ifdef FFI_CLOSURES |
| 1039 | |
| 1040 | /* Trampoline to invoke a libffi closure that wraps a Scheme |
| 1041 | procedure. */ |
| 1042 | static void |
| 1043 | invoke_closure (ffi_cif *cif, void *ret, void **args, void *data) |
| 1044 | { |
| 1045 | size_t i; |
| 1046 | SCM proc, *argv, result; |
| 1047 | |
| 1048 | proc = SCM_PACK_POINTER (data); |
| 1049 | |
| 1050 | argv = alloca (cif->nargs * sizeof (*argv)); |
| 1051 | |
| 1052 | /* Pack ARGS to SCM values, setting ARGV pointers. */ |
| 1053 | for (i = 0; i < cif->nargs; i++) |
| 1054 | argv[i] = pack (cif->arg_types[i], args[i], 0); |
| 1055 | |
| 1056 | result = scm_call_n (proc, argv, cif->nargs); |
| 1057 | |
| 1058 | unpack (cif->rtype, ret, result, 1); |
| 1059 | } |
| 1060 | |
| 1061 | SCM_DEFINE (scm_procedure_to_pointer, "procedure->pointer", 3, 0, 0, |
| 1062 | (SCM return_type, SCM proc, SCM arg_types), |
| 1063 | "Return a pointer to a C function of type @var{return_type}\n" |
| 1064 | "taking arguments of types @var{arg_types} (a list) and\n" |
| 1065 | "behaving as a proxy to procedure @var{proc}. Thus\n" |
| 1066 | "@var{proc}'s arity, supported argument types, and return\n" |
| 1067 | "type should match @var{return_type} and @var{arg_types}.\n") |
| 1068 | #define FUNC_NAME s_scm_procedure_to_pointer |
| 1069 | { |
| 1070 | SCM cif_pointer, pointer; |
| 1071 | ffi_cif *cif; |
| 1072 | ffi_status err; |
| 1073 | void *closure, *executable; |
| 1074 | |
| 1075 | cif = make_cif (return_type, arg_types, FUNC_NAME); |
| 1076 | |
| 1077 | closure = ffi_closure_alloc (sizeof (ffi_closure), &executable); |
| 1078 | err = ffi_prep_closure_loc ((ffi_closure *) closure, cif, |
| 1079 | invoke_closure, SCM_UNPACK_POINTER (proc), |
| 1080 | executable); |
| 1081 | if (err != FFI_OK) |
| 1082 | { |
| 1083 | ffi_closure_free (closure); |
| 1084 | SCM_MISC_ERROR ("`ffi_prep_closure_loc' failed", SCM_EOL); |
| 1085 | } |
| 1086 | |
| 1087 | /* CIF points to GC-managed memory and it should remain as long as |
| 1088 | POINTER (see below) is live. Wrap it in a Scheme pointer to then |
| 1089 | hold a weak reference on it. */ |
| 1090 | cif_pointer = scm_from_pointer (cif, NULL); |
| 1091 | |
| 1092 | if (closure == executable) |
| 1093 | { |
| 1094 | pointer = scm_from_pointer (executable, ffi_closure_free); |
| 1095 | register_weak_reference (pointer, |
| 1096 | scm_list_2 (proc, cif_pointer)); |
| 1097 | } |
| 1098 | else |
| 1099 | { |
| 1100 | /* CLOSURE needs to be freed eventually. However, since |
| 1101 | `GC_all_interior_pointers' is disabled, we can't just register |
| 1102 | a finalizer for CLOSURE. Instead, we create a pointer object |
| 1103 | for CLOSURE, with a finalizer, and register it as a weak |
| 1104 | reference of POINTER. */ |
| 1105 | SCM friend; |
| 1106 | |
| 1107 | pointer = scm_from_pointer (executable, NULL); |
| 1108 | friend = scm_from_pointer (closure, ffi_closure_free); |
| 1109 | |
| 1110 | register_weak_reference (pointer, |
| 1111 | scm_list_3 (proc, cif_pointer, friend)); |
| 1112 | } |
| 1113 | |
| 1114 | return pointer; |
| 1115 | } |
| 1116 | #undef FUNC_NAME |
| 1117 | |
| 1118 | #endif /* FFI_CLOSURES */ |
| 1119 | |
| 1120 | \f |
| 1121 | |
| 1122 | static void |
| 1123 | scm_init_foreign (void) |
| 1124 | { |
| 1125 | #ifndef SCM_MAGIC_SNARFER |
| 1126 | #include "libguile/foreign.x" |
| 1127 | #endif |
| 1128 | scm_define (sym_void, scm_from_uint8 (SCM_FOREIGN_TYPE_VOID)); |
| 1129 | scm_define (sym_float, scm_from_uint8 (SCM_FOREIGN_TYPE_FLOAT)); |
| 1130 | scm_define (sym_double, scm_from_uint8 (SCM_FOREIGN_TYPE_DOUBLE)); |
| 1131 | scm_define (sym_uint8, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT8)); |
| 1132 | scm_define (sym_int8, scm_from_uint8 (SCM_FOREIGN_TYPE_INT8)); |
| 1133 | scm_define (sym_uint16, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16)); |
| 1134 | scm_define (sym_int16, scm_from_uint8 (SCM_FOREIGN_TYPE_INT16)); |
| 1135 | scm_define (sym_uint32, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)); |
| 1136 | scm_define (sym_int32, scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)); |
| 1137 | scm_define (sym_uint64, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)); |
| 1138 | scm_define (sym_int64, scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)); |
| 1139 | |
| 1140 | scm_define (sym_short, |
| 1141 | #if SIZEOF_SHORT == 8 |
| 1142 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) |
| 1143 | #elif SIZEOF_SHORT == 4 |
| 1144 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) |
| 1145 | #elif SIZEOF_SHORT == 2 |
| 1146 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT16) |
| 1147 | #else |
| 1148 | # error unsupported sizeof (short) |
| 1149 | #endif |
| 1150 | ); |
| 1151 | |
| 1152 | scm_define (sym_unsigned_short, |
| 1153 | #if SIZEOF_SHORT == 8 |
| 1154 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) |
| 1155 | #elif SIZEOF_SHORT == 4 |
| 1156 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) |
| 1157 | #elif SIZEOF_SHORT == 2 |
| 1158 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16) |
| 1159 | #else |
| 1160 | # error unsupported sizeof (short) |
| 1161 | #endif |
| 1162 | ); |
| 1163 | |
| 1164 | scm_define (sym_int, |
| 1165 | #if SIZEOF_INT == 8 |
| 1166 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) |
| 1167 | #elif SIZEOF_INT == 4 |
| 1168 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) |
| 1169 | #else |
| 1170 | # error unsupported sizeof (int) |
| 1171 | #endif |
| 1172 | ); |
| 1173 | |
| 1174 | scm_define (sym_unsigned_int, |
| 1175 | #if SIZEOF_UNSIGNED_INT == 8 |
| 1176 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) |
| 1177 | #elif SIZEOF_UNSIGNED_INT == 4 |
| 1178 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) |
| 1179 | #else |
| 1180 | # error unsupported sizeof (unsigned int) |
| 1181 | #endif |
| 1182 | ); |
| 1183 | |
| 1184 | scm_define (sym_long, |
| 1185 | #if SIZEOF_LONG == 8 |
| 1186 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) |
| 1187 | #elif SIZEOF_LONG == 4 |
| 1188 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) |
| 1189 | #else |
| 1190 | # error unsupported sizeof (long) |
| 1191 | #endif |
| 1192 | ); |
| 1193 | |
| 1194 | scm_define (sym_unsigned_long, |
| 1195 | #if SIZEOF_UNSIGNED_LONG == 8 |
| 1196 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) |
| 1197 | #elif SIZEOF_UNSIGNED_LONG == 4 |
| 1198 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) |
| 1199 | #else |
| 1200 | # error unsupported sizeof (unsigned long) |
| 1201 | #endif |
| 1202 | ); |
| 1203 | |
| 1204 | scm_define (sym_size_t, |
| 1205 | #if SIZEOF_SIZE_T == 8 |
| 1206 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) |
| 1207 | #elif SIZEOF_SIZE_T == 4 |
| 1208 | scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) |
| 1209 | #else |
| 1210 | # error unsupported sizeof (size_t) |
| 1211 | #endif |
| 1212 | ); |
| 1213 | |
| 1214 | scm_define (sym_ssize_t, |
| 1215 | #if SIZEOF_SIZE_T == 8 |
| 1216 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) |
| 1217 | #elif SIZEOF_SIZE_T == 4 |
| 1218 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) |
| 1219 | #else |
| 1220 | # error unsupported sizeof (ssize_t) |
| 1221 | #endif |
| 1222 | ); |
| 1223 | |
| 1224 | scm_define (sym_ptrdiff_t, |
| 1225 | #if SCM_SIZEOF_SCM_T_PTRDIFF == 8 |
| 1226 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) |
| 1227 | #elif SCM_SIZEOF_SCM_T_PTRDIFF == 4 |
| 1228 | scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) |
| 1229 | #else |
| 1230 | # error unsupported sizeof (scm_t_ptrdiff) |
| 1231 | #endif |
| 1232 | ); |
| 1233 | |
| 1234 | null_pointer = scm_cell (scm_tc7_pointer, 0); |
| 1235 | scm_define (sym_null, null_pointer); |
| 1236 | } |
| 1237 | |
| 1238 | void |
| 1239 | scm_register_foreign (void) |
| 1240 | { |
| 1241 | scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION, |
| 1242 | "scm_init_foreign", |
| 1243 | (scm_t_extension_init_func)scm_init_foreign, |
| 1244 | NULL); |
| 1245 | pointer_weak_refs = scm_c_make_weak_table (0, SCM_WEAK_TABLE_KIND_KEY); |
| 1246 | } |
| 1247 | |
| 1248 | /* |
| 1249 | Local Variables: |
| 1250 | c-file-style: "gnu" |
| 1251 | End: |
| 1252 | */ |