git.m6w6.name Git - m6w6/ext-psi/blob - src/libffi.c

   1 #ifdef HAVE_CONFIG_H
   2 # include "config.h"
   3 #endif
   4
   5 #include "php.h"
   6
   7 #ifdef HAVE_LIBFFI
   8
   9 #include "php_psi.h"
  10 #include "libffi.h"
  11 #include "engine.h"
  12
  13 #undef PACKAGE
  14 #undef PACKAGE_BUGREPORT
  15 #undef PACKAGE_NAME
  16 #undef PACKAGE_STRING
  17 #undef PACKAGE_TARNAME
  18 #undef PACKAGE_VERSION
  19
  20 #include <ffi.h>
  21
  22 #ifndef PSI_HAVE_FFI_CLOSURE_ALLOC
  23 # if HAVE_UNISTD_H
  24 #  include <unistd.h>
  25 # endif
  26 # if HAVE_SYS_MMAN_H
  27 #  include <sys/mman.h>
  28 #  ifndef MAP_ANONYMOUS
  29 #   define MAP_ANONYMOUS MAP_ANON
  30 #  endif
  31 # endif
  32 #endif
  33
  34 static void *psi_ffi_closure_alloc(size_t s, void **code)
  35 {
  36 #ifdef PSI_HAVE_FFI_CLOSURE_ALLOC
  37         return ffi_closure_alloc(s, code);
  38 #elif HAVE_MMAP
  39         *code = mmap(NULL, s, PROT_EXEC|PROT_WRITE|PROT_READ,
  40                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  41         if (MAP_FAILED == *code) {
  42                 return NULL;
  43         }
  44         return *code;
  45 #else
  46 # error "Neither ffi_closure_alloc() nor mmap() available"
  47 #endif
  48 }
  49
  50 static ffi_status psi_ffi_prep_closure(ffi_closure **closure, void **code, ffi_cif *sig, void (*handler)(ffi_cif*,void*,void**,void*), void *data) {
  51         *closure = psi_ffi_closure_alloc(sizeof(ffi_closure), code);
  52         ZEND_ASSERT(*closure != NULL);
  53
  54 #if PSI_HAVE_FFI_PREP_CLOSURE_LOC
  55         return ffi_prep_closure_loc(*closure, sig, handler, data, *code);
  56
  57 #elif PSI_HAVE_FFI_PREP_CLOSURE
  58         return ffi_prep_closure(*code, sig, handler, data);
  59 #else
  60 # error "Neither ffi_prep_closure() nor ffi_prep_closure_loc() is available"
  61 #endif
  62
  63 }
  64
  65 static void psi_ffi_closure_free(void *c)
  66 {
  67 #ifdef PSI_HAVE_FFI_CLOSURE_ALLOC
  68         ffi_closure_free(c);
  69 #elif HAVE_MMAP
  70         munmap(c, sizeof(ffi_closure));
  71 #endif
  72 }
  73
  74 static void psi_ffi_handler(ffi_cif *signature, void *_result, void **_args, void *_data);
  75 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg);
  76
  77 typedef struct PSI_LibffiContext {
  78         ffi_cif signature;
  79         ffi_type *params[2];
  80 } PSI_LibffiContext;
  81
  82 typedef struct PSI_LibffiCall {
  83         void *code;
  84         ffi_closure *closure;
  85         ffi_cif signature;
  86         void *params[1]; /* [type1, type2, NULL, arg1, arg2] ... */
  87 } PSI_LibffiCall;
  88
  89 static inline ffi_abi psi_ffi_abi(const char *convention) {
  90         return FFI_DEFAULT_ABI;
  91 }
  92
  93 static inline PSI_LibffiCall *PSI_LibffiCallAlloc(PSI_Context *C, decl *decl) {
  94         int rc;
  95         size_t i, c = decl->args ? decl->args->count : 0;
  96         PSI_LibffiCall *call = calloc(1, sizeof(*call) + 2 * c * sizeof(void *));
  97
  98         for (i = 0; i < c; ++i) {
  99                 call->params[i] = psi_ffi_decl_arg_type(decl->args->args[i]);
 100         }
 101         call->params[c] = NULL;
 102
 103         decl->call.info = call;
 104         decl->call.rval = &decl->func->ptr;
 105         decl->call.argc = c;
 106         decl->call.args = (void **) &call->params[c+1];
 107
 108         rc = ffi_prep_cif(&call->signature, psi_ffi_abi(decl->abi->convention),
 109                         c, psi_ffi_decl_arg_type(decl->func), (ffi_type **) call->params);
 110         ZEND_ASSERT(FFI_OK == rc);
 111
 112         return call;
 113 }
 114
 115 static inline void PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
 116         PSI_LibffiContext *context = C->context;
 117         ffi_status rc;
 118
 119         rc = psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
 120         ZEND_ASSERT(FFI_OK == rc);
 121 }
 122
 123 static inline void PSI_LibffiCallFree(PSI_LibffiCall *call) {
 124         if (call->closure) {
 125                 psi_ffi_closure_free(call->closure);
 126         }
 127         free(call);
 128 }
 129
 130 static inline ffi_type *psi_ffi_token_type(token_t t) {
 131         switch (t) {
 132         default:
 133                 ZEND_ASSERT(0);
 134                 /* no break */
 135         case PSI_T_VOID:
 136                 return &ffi_type_void;
 137         case PSI_T_INT8:
 138                 return &ffi_type_sint8;
 139         case PSI_T_UINT8:
 140                 return &ffi_type_uint8;
 141         case PSI_T_INT16:
 142                 return &ffi_type_sint16;
 143         case PSI_T_UINT16:
 144                 return &ffi_type_uint16;
 145         case PSI_T_INT32:
 146                 return &ffi_type_sint32;
 147         case PSI_T_UINT32:
 148                 return &ffi_type_uint32;
 149         case PSI_T_INT64:
 150                 return &ffi_type_sint64;
 151         case PSI_T_UINT64:
 152                 return &ffi_type_uint64;
 153         case PSI_T_BOOL:
 154                 return &ffi_type_uchar;
 155         case PSI_T_INT:
 156         case PSI_T_ENUM:
 157                 return &ffi_type_sint;
 158         case PSI_T_LONG:
 159                 return &ffi_type_slong;
 160         case PSI_T_FLOAT:
 161                 return &ffi_type_float;
 162         case PSI_T_DOUBLE:
 163                 return &ffi_type_double;
 164 #ifdef HAVE_LONG_DOUBLE
 165         case PSI_T_LONG_DOUBLE:
 166                 return &ffi_type_longdouble;
 167 #endif
 168         case PSI_T_POINTER:
 169         case PSI_T_FUNCTION:
 170                 return &ffi_type_pointer;
 171         }
 172 }
 173 static inline ffi_type *psi_ffi_impl_type(token_t impl_type) {
 174         switch (impl_type) {
 175         case PSI_T_BOOL:
 176                 return &ffi_type_sint8;
 177         case PSI_T_INT:
 178                 return &ffi_type_sint64;
 179         case PSI_T_STRING:
 180                 return &ffi_type_pointer;
 181         case PSI_T_FLOAT:
 182         case PSI_T_DOUBLE:
 183                 return &ffi_type_double;
 184         EMPTY_SWITCH_DEFAULT_CASE();
 185         }
 186         return NULL;
 187 }
 188 static void psi_ffi_struct_type_dtor(void *type) {
 189         ffi_type *strct = type;
 190
 191         if (strct->elements) {
 192                 ffi_type **ptr;
 193
 194                 for (ptr = strct->elements; *ptr; ++ptr) {
 195                         free(*ptr);
 196                 }
 197                 free(strct->elements);
 198         }
 199         free(strct);
 200 }
 201
 202 static size_t psi_ffi_struct_type_pad(ffi_type **els, size_t padding) {
 203         size_t i;
 204
 205         for (i = 0; i < padding; ++i) {
 206                 ffi_type *pad = malloc(sizeof(*pad));
 207
 208                 memcpy(pad, &ffi_type_schar, sizeof(*pad));
 209                 *els++ = pad;
 210         }
 211
 212         return padding;
 213 }
 214
 215 static ffi_type **psi_ffi_struct_type_elements(decl_struct *strct) {
 216         size_t i, argc = strct->args->count, nels = 0, offset = 0, maxalign = 0;
 217         ffi_type **els = calloc(argc + 1, sizeof(*els));
 218
 219         for (i = 0; i < strct->args->count; ++i) {
 220                 decl_arg *darg = strct->args->args[i];
 221                 ffi_type *type = malloc(sizeof(*type));
 222                 size_t padding;
 223
 224                 memcpy(type, psi_ffi_decl_arg_type(darg), sizeof(*type));
 225
 226                 ZEND_ASSERT(type->size == darg->layout->len);
 227
 228                 if (type->alignment > maxalign) {
 229                         maxalign = type->alignment;
 230                 }
 231
 232                 if ((padding = psi_offset_padding(darg->layout->pos - offset, type->alignment))) {
 233                         if (nels + padding + 1 > argc) {
 234                                 argc += padding;
 235                                 els = realloc(els, (argc + 1) * sizeof(*els));
 236                                 els[argc] = NULL;
 237                         }
 238                         psi_ffi_struct_type_pad(&els[nels], padding);
 239                         nels += padding;
 240                         offset += padding;
 241                 }
 242                 ZEND_ASSERT(offset == darg->layout->pos);
 243
 244                 offset = (offset + darg->layout->len + type->alignment - 1) & ~(type->alignment - 1);
 245                 els[nels++] = type;
 246         }
 247
 248         /* apply struct alignment padding */
 249         offset = (offset + maxalign - 1) & ~(maxalign - 1);
 250
 251         ZEND_ASSERT(offset <= strct->size);
 252         if (offset < strct->size) {
 253                 psi_ffi_struct_type_pad(&els[nels], strct->size - offset);
 254         }
 255
 256         return els;
 257 }
 258 static inline ffi_type *psi_ffi_decl_type(decl_type *type) {
 259         decl_type *real = real_decl_type(type);
 260
 261         switch (real->type) {
 262         case PSI_T_FUNCTION:
 263                 if (!real->func->call.sym) {
 264                         PSI_LibffiCall *call = PSI_LibffiCallAlloc(&PSI_G(context), real->func);
 265                         ffi_status rc;
 266
 267                         rc = psi_ffi_prep_closure(&real->func->call.closure.data, &real->func->call.sym,
 268                                         &call->signature, psi_ffi_handler, NULL);
 269                         if (FFI_OK == rc) {
 270                                 real->func->call.info = call;
 271                                 real->func->call.closure.dtor = psi_ffi_closure_free;
 272                         }
 273                 }
 274                 return &ffi_type_pointer;
 275
 276         case PSI_T_STRUCT:
 277                 if (!real->strct->engine.type) {
 278                         ffi_type *strct = calloc(1, sizeof(ffi_type));
 279
 280                         strct->type = FFI_TYPE_STRUCT;
 281                         strct->size = 0;
 282                         strct->elements = psi_ffi_struct_type_elements(real->strct);
 283
 284                         real->strct->engine.type = strct;
 285                         real->strct->engine.dtor = psi_ffi_struct_type_dtor;
 286                 }
 287
 288                 return real->strct->engine.type;
 289
 290         case PSI_T_UNION:
 291                 return psi_ffi_decl_arg_type(real->unn->args->args[0]);
 292
 293         default:
 294                 return psi_ffi_token_type(real->type);
 295         }
 296 }
 297 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg) {
 298         if (darg->var->pointer_level) {
 299                 return &ffi_type_pointer;
 300         } else {
 301                 return psi_ffi_decl_type(darg->type);
 302         }
 303 }
 304
 305
 306 static inline PSI_LibffiContext *PSI_LibffiContextInit(PSI_LibffiContext *L) {
 307         ffi_status rc;
 308
 309         if (!L) {
 310                 L = malloc(sizeof(*L));
 311         }
 312         memset(L, 0, sizeof(*L));
 313
 314         L->params[0] = &ffi_type_pointer;
 315         L->params[1] = &ffi_type_pointer;
 316         rc = ffi_prep_cif(&L->signature, FFI_DEFAULT_ABI, 2, &ffi_type_void, L->params);
 317         ZEND_ASSERT(rc == FFI_OK);
 318
 319         return L;
 320 }
 321
 322 static void psi_ffi_handler(ffi_cif *_sig, void *_result, void **_args, void *_data)
 323 {
 324         psi_call(*(zend_execute_data **)_args[0], *(zval **)_args[1], _data);
 325 }
 326
 327 static void psi_ffi_init(PSI_Context *C)
 328 {
 329         C->context = PSI_LibffiContextInit(NULL);
 330 }
 331
 332 static void psi_ffi_dtor(PSI_Context *C)
 333 {
 334         if (C->decls) {
 335                 size_t i;
 336
 337                 for (i = 0; i < C->decls->count; ++i) {
 338                         decl *decl = C->decls->list[i];
 339
 340                         if (decl->call.info) {
 341                                 PSI_LibffiCallFree(decl->call.info);
 342                         }
 343                 }
 344         }
 345         free(C->context);
 346 }
 347
 348 static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 349 {
 350         size_t i, j = 0;
 351         zend_function_entry *zfe;
 352
 353         if (!C->impls) {
 354                 return NULL;
 355         }
 356
 357         zfe = calloc(C->impls->count + 1, sizeof(*zfe));
 358         for (i = 0; i < C->impls->count; ++i) {
 359                 zend_function_entry *zf = &zfe[j];
 360                 PSI_LibffiCall *call;
 361                 impl *impl = C->impls->list[i];
 362
 363                 if (!impl->decl) {
 364                         continue;
 365                 }
 366
 367                 call = PSI_LibffiCallAlloc(C, impl->decl);
 368                 PSI_LibffiCallInitClosure(C, call, impl);
 369
 370                 zf->fname = impl->func->name + (impl->func->name[0] == '\\');
 371                 zf->num_args = impl->func->args->count;
 372                 zf->handler = call->code;
 373                 zf->arg_info = psi_internal_arginfo(impl);
 374                 ++j;
 375         }
 376
 377         for (i = 0; i < C->decls->count; ++i) {
 378                 decl *decl = C->decls->list[i];
 379
 380                 if (decl->impl) {
 381                         continue;
 382                 }
 383
 384                 PSI_LibffiCallAlloc(C, decl);
 385         }
 386
 387         return zfe;
 388 }
 389
 390 static void psi_ffi_call(PSI_Context *C, decl_callinfo *decl_call, impl_vararg *va) {
 391         PSI_LibffiCall *call = decl_call->info;
 392
 393         if (va) {
 394                 ffi_status rc;
 395                 ffi_cif signature;
 396                 size_t i, nfixedargs = decl_call->argc, ntotalargs = nfixedargs + va->args->count;
 397                 void **params = calloc(2 * ntotalargs + 2, sizeof(void *));
 398
 399                 for (i = 0; i < nfixedargs; ++i) {
 400                         params[i] = call->params[i];
 401                         params[i + ntotalargs + 1] = call->params[i + nfixedargs + 1];
 402                 }
 403                 for (i = 0; i < va->args->count; ++i) {
 404                         params[nfixedargs + i] = psi_ffi_impl_type(va->types[i]);
 405                         params[nfixedargs + i + ntotalargs + 1] = &va->values[i];
 406                 }
 407 #ifdef PSI_HAVE_FFI_PREP_CIF_VAR
 408                 rc = ffi_prep_cif_var(&signature, call->signature.abi,
 409                                 nfixedargs, ntotalargs,
 410                                 call->signature.rtype, (ffi_type **) params);
 411 #else
 412                 /* FIXME: test in config.m4; assume we can just call anyway */
 413                 rc = ffi_prep_cif(&signature, call->signature.abi, ntotalargs,
 414                                 call->signature.rtype, (ffi_type **) params);
 415 #endif
 416                 ZEND_ASSERT(FFI_OK == rc);
 417                 ffi_call(&signature, FFI_FN(decl_call->sym), *decl_call->rval, &params[ntotalargs + 1]);
 418                 free(params);
 419         } else {
 420                 ffi_call(&call->signature, FFI_FN(decl_call->sym), *decl_call->rval, decl_call->args);
 421         }
 422 }
 423
 424 static PSI_ContextOps ops = {
 425         psi_ffi_init,
 426         psi_ffi_dtor,
 427         psi_ffi_compile,
 428         psi_ffi_call,
 429 };
 430
 431 PSI_ContextOps *PSI_Libffi(void)
 432 {
 433         return &ops;
 434 }
 435
 436 #endif /* HAVE_LIBFFI */