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