| 1 | /* Convert types from GDB to GCC |
| 2 | |
| 3 | Copyright (C) 2014-2017 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "compile-internal.h" |
| 24 | #include "objfiles.h" |
| 25 | |
| 26 | /* An object that maps a gdb type to a gcc type. */ |
| 27 | |
| 28 | struct type_map_instance |
| 29 | { |
| 30 | /* The gdb type. */ |
| 31 | |
| 32 | struct type *type; |
| 33 | |
| 34 | /* The corresponding gcc type handle. */ |
| 35 | |
| 36 | gcc_type gcc_type_handle; |
| 37 | }; |
| 38 | |
| 39 | /* Hash a type_map_instance. */ |
| 40 | |
| 41 | static hashval_t |
| 42 | hash_type_map_instance (const void *p) |
| 43 | { |
| 44 | const struct type_map_instance *inst = (const struct type_map_instance *) p; |
| 45 | |
| 46 | return htab_hash_pointer (inst->type); |
| 47 | } |
| 48 | |
| 49 | /* Check two type_map_instance objects for equality. */ |
| 50 | |
| 51 | static int |
| 52 | eq_type_map_instance (const void *a, const void *b) |
| 53 | { |
| 54 | const struct type_map_instance *insta = (const struct type_map_instance *) a; |
| 55 | const struct type_map_instance *instb = (const struct type_map_instance *) b; |
| 56 | |
| 57 | return insta->type == instb->type; |
| 58 | } |
| 59 | |
| 60 | \f |
| 61 | |
| 62 | /* Insert an entry into the type map associated with CONTEXT that maps |
| 63 | from the gdb type TYPE to the gcc type GCC_TYPE. It is ok for a |
| 64 | given type to be inserted more than once, provided that the exact |
| 65 | same association is made each time. This simplifies how type |
| 66 | caching works elsewhere in this file -- see how struct type caching |
| 67 | is handled. */ |
| 68 | |
| 69 | static void |
| 70 | insert_type (struct compile_c_instance *context, struct type *type, |
| 71 | gcc_type gcc_type) |
| 72 | { |
| 73 | struct type_map_instance inst, *add; |
| 74 | void **slot; |
| 75 | |
| 76 | inst.type = type; |
| 77 | inst.gcc_type_handle = gcc_type; |
| 78 | slot = htab_find_slot (context->type_map, &inst, INSERT); |
| 79 | |
| 80 | add = (struct type_map_instance *) *slot; |
| 81 | /* The type might have already been inserted in order to handle |
| 82 | recursive types. */ |
| 83 | if (add != NULL && add->gcc_type_handle != gcc_type) |
| 84 | error (_("Unexpected type id from GCC, check you use recent enough GCC.")); |
| 85 | |
| 86 | if (add == NULL) |
| 87 | { |
| 88 | add = XNEW (struct type_map_instance); |
| 89 | *add = inst; |
| 90 | *slot = add; |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | /* Convert a pointer type to its gcc representation. */ |
| 95 | |
| 96 | static gcc_type |
| 97 | convert_pointer (struct compile_c_instance *context, struct type *type) |
| 98 | { |
| 99 | gcc_type target = convert_type (context, TYPE_TARGET_TYPE (type)); |
| 100 | |
| 101 | return C_CTX (context)->c_ops->build_pointer_type (C_CTX (context), |
| 102 | target); |
| 103 | } |
| 104 | |
| 105 | /* Convert an array type to its gcc representation. */ |
| 106 | |
| 107 | static gcc_type |
| 108 | convert_array (struct compile_c_instance *context, struct type *type) |
| 109 | { |
| 110 | gcc_type element_type; |
| 111 | struct type *range = TYPE_INDEX_TYPE (type); |
| 112 | |
| 113 | element_type = convert_type (context, TYPE_TARGET_TYPE (type)); |
| 114 | |
| 115 | if (TYPE_LOW_BOUND_KIND (range) != PROP_CONST) |
| 116 | return C_CTX (context)->c_ops->error (C_CTX (context), |
| 117 | _("array type with non-constant" |
| 118 | " lower bound is not supported")); |
| 119 | if (TYPE_LOW_BOUND (range) != 0) |
| 120 | return C_CTX (context)->c_ops->error (C_CTX (context), |
| 121 | _("cannot convert array type with " |
| 122 | "non-zero lower bound to C")); |
| 123 | |
| 124 | if (TYPE_HIGH_BOUND_KIND (range) == PROP_LOCEXPR |
| 125 | || TYPE_HIGH_BOUND_KIND (range) == PROP_LOCLIST) |
| 126 | { |
| 127 | gcc_type result; |
| 128 | |
| 129 | if (TYPE_VECTOR (type)) |
| 130 | return C_CTX (context)->c_ops->error (C_CTX (context), |
| 131 | _("variably-sized vector type" |
| 132 | " is not supported")); |
| 133 | |
| 134 | std::string upper_bound |
| 135 | = c_get_range_decl_name (&TYPE_RANGE_DATA (range)->high); |
| 136 | result = C_CTX (context)->c_ops->build_vla_array_type (C_CTX (context), |
| 137 | element_type, |
| 138 | upper_bound.c_str ()); |
| 139 | return result; |
| 140 | } |
| 141 | else |
| 142 | { |
| 143 | LONGEST low_bound, high_bound, count; |
| 144 | |
| 145 | if (get_array_bounds (type, &low_bound, &high_bound) == 0) |
| 146 | count = -1; |
| 147 | else |
| 148 | { |
| 149 | gdb_assert (low_bound == 0); /* Ensured above. */ |
| 150 | count = high_bound + 1; |
| 151 | } |
| 152 | |
| 153 | if (TYPE_VECTOR (type)) |
| 154 | return C_CTX (context)->c_ops->build_vector_type (C_CTX (context), |
| 155 | element_type, |
| 156 | count); |
| 157 | return C_CTX (context)->c_ops->build_array_type (C_CTX (context), |
| 158 | element_type, count); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /* Convert a struct or union type to its gcc representation. */ |
| 163 | |
| 164 | static gcc_type |
| 165 | convert_struct_or_union (struct compile_c_instance *context, struct type *type) |
| 166 | { |
| 167 | int i; |
| 168 | gcc_type result; |
| 169 | |
| 170 | /* First we create the resulting type and enter it into our hash |
| 171 | table. This lets recursive types work. */ |
| 172 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT) |
| 173 | result = C_CTX (context)->c_ops->build_record_type (C_CTX (context)); |
| 174 | else |
| 175 | { |
| 176 | gdb_assert (TYPE_CODE (type) == TYPE_CODE_UNION); |
| 177 | result = C_CTX (context)->c_ops->build_union_type (C_CTX (context)); |
| 178 | } |
| 179 | insert_type (context, type, result); |
| 180 | |
| 181 | for (i = 0; i < TYPE_NFIELDS (type); ++i) |
| 182 | { |
| 183 | gcc_type field_type; |
| 184 | unsigned long bitsize = TYPE_FIELD_BITSIZE (type, i); |
| 185 | |
| 186 | field_type = convert_type (context, TYPE_FIELD_TYPE (type, i)); |
| 187 | if (bitsize == 0) |
| 188 | bitsize = 8 * TYPE_LENGTH (TYPE_FIELD_TYPE (type, i)); |
| 189 | C_CTX (context)->c_ops->build_add_field (C_CTX (context), result, |
| 190 | TYPE_FIELD_NAME (type, i), |
| 191 | field_type, |
| 192 | bitsize, |
| 193 | TYPE_FIELD_BITPOS (type, i)); |
| 194 | } |
| 195 | |
| 196 | C_CTX (context)->c_ops->finish_record_or_union (C_CTX (context), result, |
| 197 | TYPE_LENGTH (type)); |
| 198 | return result; |
| 199 | } |
| 200 | |
| 201 | /* Convert an enum type to its gcc representation. */ |
| 202 | |
| 203 | static gcc_type |
| 204 | convert_enum (struct compile_c_instance *context, struct type *type) |
| 205 | { |
| 206 | gcc_type int_type, result; |
| 207 | int i; |
| 208 | struct gcc_c_context *ctx = C_CTX (context); |
| 209 | |
| 210 | int_type = ctx->c_ops->int_type_v0 (ctx, |
| 211 | TYPE_UNSIGNED (type), |
| 212 | TYPE_LENGTH (type)); |
| 213 | |
| 214 | result = ctx->c_ops->build_enum_type (ctx, int_type); |
| 215 | for (i = 0; i < TYPE_NFIELDS (type); ++i) |
| 216 | { |
| 217 | ctx->c_ops->build_add_enum_constant (ctx, |
| 218 | result, |
| 219 | TYPE_FIELD_NAME (type, i), |
| 220 | TYPE_FIELD_ENUMVAL (type, i)); |
| 221 | } |
| 222 | |
| 223 | ctx->c_ops->finish_enum_type (ctx, result); |
| 224 | |
| 225 | return result; |
| 226 | } |
| 227 | |
| 228 | /* Convert a function type to its gcc representation. */ |
| 229 | |
| 230 | static gcc_type |
| 231 | convert_func (struct compile_c_instance *context, struct type *type) |
| 232 | { |
| 233 | int i; |
| 234 | gcc_type result, return_type; |
| 235 | struct gcc_type_array array; |
| 236 | int is_varargs = TYPE_VARARGS (type) || !TYPE_PROTOTYPED (type); |
| 237 | |
| 238 | struct type *target_type = TYPE_TARGET_TYPE (type); |
| 239 | |
| 240 | /* Functions with no debug info have no return type. Ideally we'd |
| 241 | want to fallback to the type of the cast just before the |
| 242 | function, like GDB's built-in expression parser, but we don't |
| 243 | have access to that type here. For now, fallback to int, like |
| 244 | GDB's parser used to do. */ |
| 245 | if (target_type == NULL) |
| 246 | { |
| 247 | if (TYPE_OBJFILE_OWNED (type)) |
| 248 | target_type = objfile_type (TYPE_OWNER (type).objfile)->builtin_int; |
| 249 | else |
| 250 | target_type = builtin_type (TYPE_OWNER (type).gdbarch)->builtin_int; |
| 251 | warning (_("function has unknown return type; assuming int")); |
| 252 | } |
| 253 | |
| 254 | /* This approach means we can't make self-referential function |
| 255 | types. Those are impossible in C, though. */ |
| 256 | return_type = convert_type (context, target_type); |
| 257 | |
| 258 | array.n_elements = TYPE_NFIELDS (type); |
| 259 | array.elements = XNEWVEC (gcc_type, TYPE_NFIELDS (type)); |
| 260 | for (i = 0; i < TYPE_NFIELDS (type); ++i) |
| 261 | array.elements[i] = convert_type (context, TYPE_FIELD_TYPE (type, i)); |
| 262 | |
| 263 | result = C_CTX (context)->c_ops->build_function_type (C_CTX (context), |
| 264 | return_type, |
| 265 | &array, is_varargs); |
| 266 | xfree (array.elements); |
| 267 | |
| 268 | return result; |
| 269 | } |
| 270 | |
| 271 | /* Convert an integer type to its gcc representation. */ |
| 272 | |
| 273 | static gcc_type |
| 274 | convert_int (struct compile_c_instance *context, struct type *type) |
| 275 | { |
| 276 | return C_CTX (context)->c_ops->int_type_v0 (C_CTX (context), |
| 277 | TYPE_UNSIGNED (type), |
| 278 | TYPE_LENGTH (type)); |
| 279 | } |
| 280 | |
| 281 | /* Convert a floating-point type to its gcc representation. */ |
| 282 | |
| 283 | static gcc_type |
| 284 | convert_float (struct compile_c_instance *context, struct type *type) |
| 285 | { |
| 286 | return C_CTX (context)->c_ops->float_type_v0 (C_CTX (context), |
| 287 | TYPE_LENGTH (type)); |
| 288 | } |
| 289 | |
| 290 | /* Convert the 'void' type to its gcc representation. */ |
| 291 | |
| 292 | static gcc_type |
| 293 | convert_void (struct compile_c_instance *context, struct type *type) |
| 294 | { |
| 295 | return C_CTX (context)->c_ops->void_type (C_CTX (context)); |
| 296 | } |
| 297 | |
| 298 | /* Convert a boolean type to its gcc representation. */ |
| 299 | |
| 300 | static gcc_type |
| 301 | convert_bool (struct compile_c_instance *context, struct type *type) |
| 302 | { |
| 303 | return C_CTX (context)->c_ops->bool_type (C_CTX (context)); |
| 304 | } |
| 305 | |
| 306 | /* Convert a qualified type to its gcc representation. */ |
| 307 | |
| 308 | static gcc_type |
| 309 | convert_qualified (struct compile_c_instance *context, struct type *type) |
| 310 | { |
| 311 | struct type *unqual = make_unqualified_type (type); |
| 312 | gcc_type unqual_converted; |
| 313 | gcc_qualifiers_flags quals = 0; |
| 314 | |
| 315 | unqual_converted = convert_type (context, unqual); |
| 316 | |
| 317 | if (TYPE_CONST (type)) |
| 318 | quals |= GCC_QUALIFIER_CONST; |
| 319 | if (TYPE_VOLATILE (type)) |
| 320 | quals |= GCC_QUALIFIER_VOLATILE; |
| 321 | if (TYPE_RESTRICT (type)) |
| 322 | quals |= GCC_QUALIFIER_RESTRICT; |
| 323 | |
| 324 | return C_CTX (context)->c_ops->build_qualified_type (C_CTX (context), |
| 325 | unqual_converted, |
| 326 | quals); |
| 327 | } |
| 328 | |
| 329 | /* Convert a complex type to its gcc representation. */ |
| 330 | |
| 331 | static gcc_type |
| 332 | convert_complex (struct compile_c_instance *context, struct type *type) |
| 333 | { |
| 334 | gcc_type base = convert_type (context, TYPE_TARGET_TYPE (type)); |
| 335 | |
| 336 | return C_CTX (context)->c_ops->build_complex_type (C_CTX (context), base); |
| 337 | } |
| 338 | |
| 339 | /* A helper function which knows how to convert most types from their |
| 340 | gdb representation to the corresponding gcc form. This examines |
| 341 | the TYPE and dispatches to the appropriate conversion function. It |
| 342 | returns the gcc type. */ |
| 343 | |
| 344 | static gcc_type |
| 345 | convert_type_basic (struct compile_c_instance *context, struct type *type) |
| 346 | { |
| 347 | /* If we are converting a qualified type, first convert the |
| 348 | unqualified type and then apply the qualifiers. */ |
| 349 | if ((TYPE_INSTANCE_FLAGS (type) & (TYPE_INSTANCE_FLAG_CONST |
| 350 | | TYPE_INSTANCE_FLAG_VOLATILE |
| 351 | | TYPE_INSTANCE_FLAG_RESTRICT)) != 0) |
| 352 | return convert_qualified (context, type); |
| 353 | |
| 354 | switch (TYPE_CODE (type)) |
| 355 | { |
| 356 | case TYPE_CODE_PTR: |
| 357 | return convert_pointer (context, type); |
| 358 | |
| 359 | case TYPE_CODE_ARRAY: |
| 360 | return convert_array (context, type); |
| 361 | |
| 362 | case TYPE_CODE_STRUCT: |
| 363 | case TYPE_CODE_UNION: |
| 364 | return convert_struct_or_union (context, type); |
| 365 | |
| 366 | case TYPE_CODE_ENUM: |
| 367 | return convert_enum (context, type); |
| 368 | |
| 369 | case TYPE_CODE_FUNC: |
| 370 | return convert_func (context, type); |
| 371 | |
| 372 | case TYPE_CODE_INT: |
| 373 | return convert_int (context, type); |
| 374 | |
| 375 | case TYPE_CODE_FLT: |
| 376 | return convert_float (context, type); |
| 377 | |
| 378 | case TYPE_CODE_VOID: |
| 379 | return convert_void (context, type); |
| 380 | |
| 381 | case TYPE_CODE_BOOL: |
| 382 | return convert_bool (context, type); |
| 383 | |
| 384 | case TYPE_CODE_COMPLEX: |
| 385 | return convert_complex (context, type); |
| 386 | |
| 387 | case TYPE_CODE_ERROR: |
| 388 | { |
| 389 | /* Ideally, if we get here due to a cast expression, we'd use |
| 390 | the cast-to type as the variable's type, like GDB's |
| 391 | built-in parser does. For now, assume "int" like GDB's |
| 392 | built-in parser used to do, but at least warn. */ |
| 393 | struct type *fallback; |
| 394 | if (TYPE_OBJFILE_OWNED (type)) |
| 395 | fallback = objfile_type (TYPE_OWNER (type).objfile)->builtin_int; |
| 396 | else |
| 397 | fallback = builtin_type (TYPE_OWNER (type).gdbarch)->builtin_int; |
| 398 | warning (_("variable has unknown type; assuming int")); |
| 399 | return convert_int (context, fallback); |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | return C_CTX (context)->c_ops->error (C_CTX (context), |
| 404 | _("cannot convert gdb type " |
| 405 | "to gcc type")); |
| 406 | } |
| 407 | |
| 408 | /* See compile-internal.h. */ |
| 409 | |
| 410 | gcc_type |
| 411 | convert_type (struct compile_c_instance *context, struct type *type) |
| 412 | { |
| 413 | struct type_map_instance inst, *found; |
| 414 | gcc_type result; |
| 415 | |
| 416 | /* We don't ever have to deal with typedefs in this code, because |
| 417 | those are only needed as symbols by the C compiler. */ |
| 418 | type = check_typedef (type); |
| 419 | |
| 420 | inst.type = type; |
| 421 | found = (struct type_map_instance *) htab_find (context->type_map, &inst); |
| 422 | if (found != NULL) |
| 423 | return found->gcc_type_handle; |
| 424 | |
| 425 | result = convert_type_basic (context, type); |
| 426 | insert_type (context, type, result); |
| 427 | return result; |
| 428 | } |
| 429 | |
| 430 | \f |
| 431 | |
| 432 | /* Delete the compiler instance C. */ |
| 433 | |
| 434 | static void |
| 435 | delete_instance (struct compile_instance *c) |
| 436 | { |
| 437 | struct compile_c_instance *context = (struct compile_c_instance *) c; |
| 438 | |
| 439 | context->base.fe->ops->destroy (context->base.fe); |
| 440 | htab_delete (context->type_map); |
| 441 | if (context->symbol_err_map != NULL) |
| 442 | htab_delete (context->symbol_err_map); |
| 443 | xfree (context); |
| 444 | } |
| 445 | |
| 446 | /* See compile-internal.h. */ |
| 447 | |
| 448 | struct compile_instance * |
| 449 | new_compile_instance (struct gcc_c_context *fe) |
| 450 | { |
| 451 | struct compile_c_instance *result = XCNEW (struct compile_c_instance); |
| 452 | |
| 453 | result->base.fe = &fe->base; |
| 454 | result->base.destroy = delete_instance; |
| 455 | result->base.gcc_target_options = ("-std=gnu11" |
| 456 | /* Otherwise the .o file may need |
| 457 | "_Unwind_Resume" and |
| 458 | "__gcc_personality_v0". */ |
| 459 | " -fno-exceptions"); |
| 460 | |
| 461 | result->type_map = htab_create_alloc (10, hash_type_map_instance, |
| 462 | eq_type_map_instance, |
| 463 | xfree, xcalloc, xfree); |
| 464 | |
| 465 | fe->c_ops->set_callbacks (fe, gcc_convert_symbol, |
| 466 | gcc_symbol_address, result); |
| 467 | |
| 468 | return &result->base; |
| 469 | } |