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 *_sig, void *_result, void **_args, void *_data)
  75 {
  76         psi_call(*(zend_execute_data **)_args[0], *(zval **)_args[1], _data);
  77 }
  78
  79 static void psi_ffi_callback(ffi_cif *_sig, void *_result, void **_args, void *_data)
  80 {
  81         unsigned argc = _sig->nargs;
  82         void **argv = _args;
  83         ffi_arg *res = _result;
  84         let_stmt *let;
  85         decl_arg *darg = let->var->arg;
  86         decl *decl_cb = darg->type->func;
  87         let_callback *cb = let->val->data.callback;
  88         impl_arg *iarg = cb->func->arg;
  89         size_t i, argc = cb->args->count;
  90         zval return_value, *argv = calloc(argc, sizeof(*argv));
  91
  92         // prepare args for the userland call
  93         for (i = 0; i < decl_cb->args->count; ++i) {
  94
  95         }
  96         for (i = 0; i < cb->args->count; ++i) {
  97                 psi_do_set(&argv[i], cb->args->vals[i]);
  98         }
  99         zend_fcall_info_argp(iarg->val.zend.cb->fci, argc, argv);
 100         zend_fcall_info_call(&iarg->val.zend.cb->fci, &iarg->val.zend.cb->fcc,
 101                         &return_value, NULL);
 102         // marshal return value of the userland call
 103         switch (cb->func->type) {
 104         case PSI_T_BOOLVAL:
 105                 break;
 106         case PSI_T_INTVAL:
 107                 break;
 108         case PSI_T_FLOATVAL:
 109                 break;
 110         case PSI_T_PATHVAL:
 111         case PSI_T_STRVAL:
 112                 break;
 113         case PSI_T_STRLEN:
 114                 break;
 115         case PSI_T_ARRVAL:
 116                 break;
 117         case PSI_T_OBJVAL:
 118                 break;
 119         case PSI_T_CALLBACK:
 120                 break;
 121         EMPTY_SWITCH_DEFAULT_CASE();
 122         }
 123         darg->ptr = psi_let_val(cb->func->type, iarg, darg->ptr, real_decl_type(darg->type)->strct, &darg->mem);
 124 }
 125
 126 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg);
 127
 128 typedef struct PSI_LibffiContext {
 129         ffi_cif signature;
 130         ffi_type *params[2];
 131 } PSI_LibffiContext;
 132
 133 typedef struct PSI_LibffiCall {
 134         void *code;
 135         ffi_closure *closure;
 136         ffi_cif signature;
 137         void *params[1]; /* [type1, type2, NULL, arg1, arg2] ... */
 138 } PSI_LibffiCall;
 139
 140 static inline ffi_abi psi_ffi_abi(const char *convention) {
 141         return FFI_DEFAULT_ABI;
 142 }
 143
 144 static inline PSI_LibffiCall *PSI_LibffiCallAlloc(PSI_Context *C, decl *decl) {
 145         int rc;
 146         size_t i, c = decl->args ? decl->args->count : 0;
 147         PSI_LibffiCall *call = calloc(1, sizeof(*call) + 2 * c * sizeof(void *));
 148
 149         for (i = 0; i < c; ++i) {
 150                 call->params[i] = psi_ffi_decl_arg_type(decl->args->args[i]);
 151         }
 152         call->params[c] = NULL;
 153
 154         decl->call.info = call;
 155         decl->call.rval = &decl->func->ptr;
 156         decl->call.argc = c;
 157         decl->call.args = (void **) &call->params[c+1];
 158
 159         rc = ffi_prep_cif(&call->signature, psi_ffi_abi(decl->abi->convention),
 160                         c, psi_ffi_decl_arg_type(decl->func), (ffi_type **) call->params);
 161         ZEND_ASSERT(FFI_OK == rc);
 162
 163         return call;
 164 }
 165
 166 static inline void PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
 167         PSI_LibffiContext *context = C->context;
 168         ffi_status rc;
 169
 170         rc = psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
 171         ZEND_ASSERT(FFI_OK == rc);
 172 }
 173
 174 static inline void PSI_LibffiCallFree(PSI_LibffiCall *call) {
 175         if (call->closure) {
 176                 psi_ffi_closure_free(call->closure);
 177         }
 178         free(call);
 179 }
 180
 181 static inline ffi_type *psi_ffi_token_type(token_t t) {
 182         switch (t) {
 183         default:
 184                 ZEND_ASSERT(0);
 185                 /* no break */
 186         case PSI_T_VOID:
 187                 return &ffi_type_void;
 188         case PSI_T_INT8:
 189                 return &ffi_type_sint8;
 190         case PSI_T_UINT8:
 191                 return &ffi_type_uint8;
 192         case PSI_T_INT16:
 193                 return &ffi_type_sint16;
 194         case PSI_T_UINT16:
 195                 return &ffi_type_uint16;
 196         case PSI_T_INT32:
 197                 return &ffi_type_sint32;
 198         case PSI_T_UINT32:
 199                 return &ffi_type_uint32;
 200         case PSI_T_INT64:
 201                 return &ffi_type_sint64;
 202         case PSI_T_UINT64:
 203                 return &ffi_type_uint64;
 204         case PSI_T_BOOL:
 205                 return &ffi_type_uchar;
 206         case PSI_T_INT:
 207         case PSI_T_ENUM:
 208                 return &ffi_type_sint;
 209         case PSI_T_LONG:
 210                 return &ffi_type_slong;
 211         case PSI_T_FLOAT:
 212                 return &ffi_type_float;
 213         case PSI_T_DOUBLE:
 214                 return &ffi_type_double;
 215 #ifdef HAVE_LONG_DOUBLE
 216         case PSI_T_LONG_DOUBLE:
 217                 return &ffi_type_longdouble;
 218 #endif
 219         case PSI_T_POINTER:
 220         case PSI_T_FUNCTION:
 221                 return &ffi_type_pointer;
 222         }
 223 }
 224 static inline ffi_type *psi_ffi_impl_type(token_t impl_type) {
 225         switch (impl_type) {
 226         case PSI_T_BOOL:
 227                 return &ffi_type_sint8;
 228         case PSI_T_INT:
 229                 return &ffi_type_sint64;
 230         case PSI_T_STRING:
 231                 return &ffi_type_pointer;
 232         case PSI_T_FLOAT:
 233         case PSI_T_DOUBLE:
 234                 return &ffi_type_double;
 235         EMPTY_SWITCH_DEFAULT_CASE();
 236         }
 237         return NULL;
 238 }
 239 static void psi_ffi_struct_type_dtor(void *type) {
 240         ffi_type *strct = type;
 241
 242         if (strct->elements) {
 243                 ffi_type **ptr;
 244
 245                 for (ptr = strct->elements; *ptr; ++ptr) {
 246                         free(*ptr);
 247                 }
 248                 free(strct->elements);
 249         }
 250         free(strct);
 251 }
 252
 253 static size_t psi_ffi_struct_type_pad(ffi_type **els, size_t padding) {
 254         size_t i;
 255
 256         for (i = 0; i < padding; ++i) {
 257                 ffi_type *pad = malloc(sizeof(*pad));
 258
 259                 memcpy(pad, &ffi_type_schar, sizeof(*pad));
 260                 *els++ = pad;
 261         }
 262
 263         return padding;
 264 }
 265
 266 static ffi_type **psi_ffi_struct_type_elements(decl_struct *strct) {
 267         size_t i, argc = strct->args->count, nels = 0, offset = 0, maxalign = 0;
 268         ffi_type **els = calloc(argc + 1, sizeof(*els));
 269
 270         for (i = 0; i < strct->args->count; ++i) {
 271                 decl_arg *darg = strct->args->args[i];
 272                 ffi_type *type = malloc(sizeof(*type));
 273                 size_t padding;
 274
 275                 memcpy(type, psi_ffi_decl_arg_type(darg), sizeof(*type));
 276
 277                 ZEND_ASSERT(type->size == darg->layout->len);
 278
 279                 if (type->alignment > maxalign) {
 280                         maxalign = type->alignment;
 281                 }
 282
 283                 if ((padding = psi_offset_padding(darg->layout->pos - offset, type->alignment))) {
 284                         if (nels + padding + 1 > argc) {
 285                                 argc += padding;
 286                                 els = realloc(els, (argc + 1) * sizeof(*els));
 287                                 els[argc] = NULL;
 288                         }
 289                         psi_ffi_struct_type_pad(&els[nels], padding);
 290                         nels += padding;
 291                         offset += padding;
 292                 }
 293                 ZEND_ASSERT(offset == darg->layout->pos);
 294
 295                 offset = (offset + darg->layout->len + type->alignment - 1) & ~(type->alignment - 1);
 296                 els[nels++] = type;
 297         }
 298
 299         /* apply struct alignment padding */
 300         offset = (offset + maxalign - 1) & ~(maxalign - 1);
 301
 302         ZEND_ASSERT(offset <= strct->size);
 303         if (offset < strct->size) {
 304                 psi_ffi_struct_type_pad(&els[nels], strct->size - offset);
 305         }
 306
 307         return els;
 308 }
 309 static inline ffi_type *psi_ffi_decl_type(decl_type *type) {
 310         decl_type *real = real_decl_type(type);
 311
 312         switch (real->type) {
 313         case PSI_T_FUNCTION:
 314                 if (!real->func->call.sym) {
 315                         PSI_LibffiCall *call = PSI_LibffiCallAlloc(&PSI_G(context), real->func);
 316                         ffi_status rc;
 317
 318                         rc = psi_ffi_prep_closure(
 319                                         (void *) &real->func->call.closure.data,
 320                                         &real->func->call.sym, &call->signature, psi_ffi_handler, NULL);
 321                         if (FFI_OK == rc) {
 322                                 real->func->call.info = call;
 323                                 real->func->call.closure.dtor = psi_ffi_closure_free;
 324                         }
 325                 }
 326                 return &ffi_type_pointer;
 327
 328         case PSI_T_STRUCT:
 329                 if (!real->strct->engine.type) {
 330                         ffi_type *strct = calloc(1, sizeof(ffi_type));
 331
 332                         strct->type = FFI_TYPE_STRUCT;
 333                         strct->size = 0;
 334                         strct->elements = psi_ffi_struct_type_elements(real->strct);
 335
 336                         real->strct->engine.type = strct;
 337                         real->strct->engine.dtor = psi_ffi_struct_type_dtor;
 338                 }
 339
 340                 return real->strct->engine.type;
 341
 342         case PSI_T_UNION:
 343                 return psi_ffi_decl_arg_type(real->unn->args->args[0]);
 344
 345         default:
 346                 return psi_ffi_token_type(real->type);
 347         }
 348 }
 349 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg) {
 350         if (darg->var->pointer_level) {
 351                 return &ffi_type_pointer;
 352         } else {
 353                 return psi_ffi_decl_type(darg->type);
 354         }
 355 }
 356
 357
 358 static inline PSI_LibffiContext *PSI_LibffiContextInit(PSI_LibffiContext *L) {
 359         ffi_status rc;
 360
 361         if (!L) {
 362                 L = malloc(sizeof(*L));
 363         }
 364         memset(L, 0, sizeof(*L));
 365
 366         L->params[0] = &ffi_type_pointer;
 367         L->params[1] = &ffi_type_pointer;
 368         rc = ffi_prep_cif(&L->signature, FFI_DEFAULT_ABI, 2, &ffi_type_void, L->params);
 369         ZEND_ASSERT(rc == FFI_OK);
 370
 371         return L;
 372 }
 373
 374 static void psi_ffi_init(PSI_Context *C)
 375 {
 376         C->context = PSI_LibffiContextInit(NULL);
 377 }
 378
 379 static void psi_ffi_dtor(PSI_Context *C)
 380 {
 381         if (C->decls) {
 382                 size_t i;
 383
 384                 for (i = 0; i < C->decls->count; ++i) {
 385                         decl *decl = C->decls->list[i];
 386
 387                         if (decl->call.info) {
 388                                 PSI_LibffiCallFree(decl->call.info);
 389                         }
 390                 }
 391         }
 392         free(C->context);
 393 }
 394
 395 static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 396 {
 397         size_t i, j = 0;
 398         zend_function_entry *zfe;
 399
 400         if (!C->impls) {
 401                 return NULL;
 402         }
 403
 404         zfe = calloc(C->impls->count + 1, sizeof(*zfe));
 405         for (i = 0; i < C->impls->count; ++i) {
 406                 zend_function_entry *zf = &zfe[j];
 407                 PSI_LibffiCall *call;
 408                 impl *impl = C->impls->list[i];
 409
 410                 if (!impl->decl) {
 411                         continue;
 412                 }
 413
 414                 call = PSI_LibffiCallAlloc(C, impl->decl);
 415                 PSI_LibffiCallInitClosure(C, call, impl);
 416
 417                 zf->fname = impl->func->name + (impl->func->name[0] == '\\');
 418                 zf->num_args = impl->func->args->count;
 419                 zf->handler = call->code;
 420                 zf->arg_info = psi_internal_arginfo(impl);
 421                 ++j;
 422         }
 423
 424         for (i = 0; i < C->decls->count; ++i) {
 425                 decl *decl = C->decls->list[i];
 426
 427                 if (decl->impl) {
 428                         continue;
 429                 }
 430
 431                 PSI_LibffiCallAlloc(C, decl);
 432         }
 433
 434         return zfe;
 435 }
 436
 437 static void psi_ffi_call(PSI_Context *C, decl_callinfo *decl_call, impl_vararg *va) {
 438         PSI_LibffiCall *call = decl_call->info;
 439
 440         if (va) {
 441                 ffi_status rc;
 442                 ffi_cif signature;
 443                 size_t i, nfixedargs = decl_call->argc, ntotalargs = nfixedargs + va->args->count;
 444                 void **params = calloc(2 * ntotalargs + 2, sizeof(void *));
 445
 446                 for (i = 0; i < nfixedargs; ++i) {
 447                         params[i] = call->params[i];
 448                         params[i + ntotalargs + 1] = call->params[i + nfixedargs + 1];
 449                 }
 450                 for (i = 0; i < va->args->count; ++i) {
 451                         params[nfixedargs + i] = psi_ffi_impl_type(va->types[i]);
 452                         params[nfixedargs + i + ntotalargs + 1] = &va->values[i];
 453                 }
 454 #ifdef PSI_HAVE_FFI_PREP_CIF_VAR
 455                 rc = ffi_prep_cif_var(&signature, call->signature.abi,
 456                                 nfixedargs, ntotalargs,
 457                                 call->signature.rtype, (ffi_type **) params);
 458 #else
 459                 /* FIXME: test in config.m4; assume we can just call anyway */
 460                 rc = ffi_prep_cif(&signature, call->signature.abi, ntotalargs,
 461                                 call->signature.rtype, (ffi_type **) params);
 462 #endif
 463                 ZEND_ASSERT(FFI_OK == rc);
 464                 ffi_call(&signature, FFI_FN(decl_call->sym), *decl_call->rval, &params[ntotalargs + 1]);
 465                 free(params);
 466         } else {
 467                 ffi_call(&call->signature, FFI_FN(decl_call->sym), *decl_call->rval, decl_call->args);
 468         }
 469 }
 470
 471 static PSI_ContextOps ops = {
 472         psi_ffi_init,
 473         psi_ffi_dtor,
 474         psi_ffi_compile,
 475         psi_ffi_call,
 476 };
 477
 478 PSI_ContextOps *PSI_Libffi(void)
 479 {
 480         return &ops;
 481 }
 482
 483 #endif /* HAVE_LIBFFI */