| 1 | /* DWARF 2 location expression support for GDB. |
| 2 | |
| 3 | Copyright (C) 2003, 2005, 2007-2012 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by Daniel Jacobowitz, MontaVista Software, Inc. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "ui-out.h" |
| 24 | #include "value.h" |
| 25 | #include "frame.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "target.h" |
| 28 | #include "inferior.h" |
| 29 | #include "ax.h" |
| 30 | #include "ax-gdb.h" |
| 31 | #include "regcache.h" |
| 32 | #include "objfiles.h" |
| 33 | #include "exceptions.h" |
| 34 | #include "block.h" |
| 35 | #include "gdbcmd.h" |
| 36 | |
| 37 | #include "dwarf2.h" |
| 38 | #include "dwarf2expr.h" |
| 39 | #include "dwarf2loc.h" |
| 40 | #include "dwarf2-frame.h" |
| 41 | |
| 42 | #include "gdb_string.h" |
| 43 | #include "gdb_assert.h" |
| 44 | |
| 45 | DEF_VEC_I(int); |
| 46 | |
| 47 | extern int dwarf2_always_disassemble; |
| 48 | |
| 49 | static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, |
| 50 | const gdb_byte **start, size_t *length); |
| 51 | |
| 52 | static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs; |
| 53 | |
| 54 | static struct value *dwarf2_evaluate_loc_desc_full (struct type *type, |
| 55 | struct frame_info *frame, |
| 56 | const gdb_byte *data, |
| 57 | unsigned short size, |
| 58 | struct dwarf2_per_cu_data *per_cu, |
| 59 | LONGEST byte_offset); |
| 60 | |
| 61 | /* A function for dealing with location lists. Given a |
| 62 | symbol baton (BATON) and a pc value (PC), find the appropriate |
| 63 | location expression, set *LOCEXPR_LENGTH, and return a pointer |
| 64 | to the beginning of the expression. Returns NULL on failure. |
| 65 | |
| 66 | For now, only return the first matching location expression; there |
| 67 | can be more than one in the list. */ |
| 68 | |
| 69 | const gdb_byte * |
| 70 | dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton, |
| 71 | size_t *locexpr_length, CORE_ADDR pc) |
| 72 | { |
| 73 | CORE_ADDR low, high; |
| 74 | const gdb_byte *loc_ptr, *buf_end; |
| 75 | int length; |
| 76 | struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu); |
| 77 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 78 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 79 | unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu); |
| 80 | int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); |
| 81 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); |
| 82 | /* Adjust base_address for relocatable objects. */ |
| 83 | CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu); |
| 84 | CORE_ADDR base_address = baton->base_address + base_offset; |
| 85 | |
| 86 | loc_ptr = baton->data; |
| 87 | buf_end = baton->data + baton->size; |
| 88 | |
| 89 | while (1) |
| 90 | { |
| 91 | if (buf_end - loc_ptr < 2 * addr_size) |
| 92 | error (_("dwarf2_find_location_expression: " |
| 93 | "Corrupted DWARF expression.")); |
| 94 | |
| 95 | if (signed_addr_p) |
| 96 | low = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| 97 | else |
| 98 | low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| 99 | loc_ptr += addr_size; |
| 100 | |
| 101 | if (signed_addr_p) |
| 102 | high = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| 103 | else |
| 104 | high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| 105 | loc_ptr += addr_size; |
| 106 | |
| 107 | /* A base-address-selection entry. */ |
| 108 | if ((low & base_mask) == base_mask) |
| 109 | { |
| 110 | base_address = high + base_offset; |
| 111 | continue; |
| 112 | } |
| 113 | |
| 114 | /* An end-of-list entry. */ |
| 115 | if (low == 0 && high == 0) |
| 116 | { |
| 117 | *locexpr_length = 0; |
| 118 | return NULL; |
| 119 | } |
| 120 | |
| 121 | /* Otherwise, a location expression entry. */ |
| 122 | low += base_address; |
| 123 | high += base_address; |
| 124 | |
| 125 | length = extract_unsigned_integer (loc_ptr, 2, byte_order); |
| 126 | loc_ptr += 2; |
| 127 | |
| 128 | if (low == high && pc == low) |
| 129 | { |
| 130 | /* This is entry PC record present only at entry point |
| 131 | of a function. Verify it is really the function entry point. */ |
| 132 | |
| 133 | struct block *pc_block = block_for_pc (pc); |
| 134 | struct symbol *pc_func = NULL; |
| 135 | |
| 136 | if (pc_block) |
| 137 | pc_func = block_linkage_function (pc_block); |
| 138 | |
| 139 | if (pc_func && pc == BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func))) |
| 140 | { |
| 141 | *locexpr_length = length; |
| 142 | return loc_ptr; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (pc >= low && pc < high) |
| 147 | { |
| 148 | *locexpr_length = length; |
| 149 | return loc_ptr; |
| 150 | } |
| 151 | |
| 152 | loc_ptr += length; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | /* This is the baton used when performing dwarf2 expression |
| 157 | evaluation. */ |
| 158 | struct dwarf_expr_baton |
| 159 | { |
| 160 | struct frame_info *frame; |
| 161 | struct dwarf2_per_cu_data *per_cu; |
| 162 | }; |
| 163 | |
| 164 | /* Helper functions for dwarf2_evaluate_loc_desc. */ |
| 165 | |
| 166 | /* Using the frame specified in BATON, return the value of register |
| 167 | REGNUM, treated as a pointer. */ |
| 168 | static CORE_ADDR |
| 169 | dwarf_expr_read_reg (void *baton, int dwarf_regnum) |
| 170 | { |
| 171 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
| 172 | struct gdbarch *gdbarch = get_frame_arch (debaton->frame); |
| 173 | CORE_ADDR result; |
| 174 | int regnum; |
| 175 | |
| 176 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum); |
| 177 | result = address_from_register (builtin_type (gdbarch)->builtin_data_ptr, |
| 178 | regnum, debaton->frame); |
| 179 | return result; |
| 180 | } |
| 181 | |
| 182 | /* Read memory at ADDR (length LEN) into BUF. */ |
| 183 | |
| 184 | static void |
| 185 | dwarf_expr_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
| 186 | { |
| 187 | read_memory (addr, buf, len); |
| 188 | } |
| 189 | |
| 190 | /* Using the frame specified in BATON, find the location expression |
| 191 | describing the frame base. Return a pointer to it in START and |
| 192 | its length in LENGTH. */ |
| 193 | static void |
| 194 | dwarf_expr_frame_base (void *baton, const gdb_byte **start, size_t * length) |
| 195 | { |
| 196 | /* FIXME: cagney/2003-03-26: This code should be using |
| 197 | get_frame_base_address(), and then implement a dwarf2 specific |
| 198 | this_base method. */ |
| 199 | struct symbol *framefunc; |
| 200 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
| 201 | |
| 202 | /* Use block_linkage_function, which returns a real (not inlined) |
| 203 | function, instead of get_frame_function, which may return an |
| 204 | inlined function. */ |
| 205 | framefunc = block_linkage_function (get_frame_block (debaton->frame, NULL)); |
| 206 | |
| 207 | /* If we found a frame-relative symbol then it was certainly within |
| 208 | some function associated with a frame. If we can't find the frame, |
| 209 | something has gone wrong. */ |
| 210 | gdb_assert (framefunc != NULL); |
| 211 | |
| 212 | dwarf_expr_frame_base_1 (framefunc, |
| 213 | get_frame_address_in_block (debaton->frame), |
| 214 | start, length); |
| 215 | } |
| 216 | |
| 217 | static void |
| 218 | dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, |
| 219 | const gdb_byte **start, size_t *length) |
| 220 | { |
| 221 | if (SYMBOL_LOCATION_BATON (framefunc) == NULL) |
| 222 | *length = 0; |
| 223 | else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs) |
| 224 | { |
| 225 | struct dwarf2_loclist_baton *symbaton; |
| 226 | |
| 227 | symbaton = SYMBOL_LOCATION_BATON (framefunc); |
| 228 | *start = dwarf2_find_location_expression (symbaton, length, pc); |
| 229 | } |
| 230 | else |
| 231 | { |
| 232 | struct dwarf2_locexpr_baton *symbaton; |
| 233 | |
| 234 | symbaton = SYMBOL_LOCATION_BATON (framefunc); |
| 235 | if (symbaton != NULL) |
| 236 | { |
| 237 | *length = symbaton->size; |
| 238 | *start = symbaton->data; |
| 239 | } |
| 240 | else |
| 241 | *length = 0; |
| 242 | } |
| 243 | |
| 244 | if (*length == 0) |
| 245 | error (_("Could not find the frame base for \"%s\"."), |
| 246 | SYMBOL_NATURAL_NAME (framefunc)); |
| 247 | } |
| 248 | |
| 249 | /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for |
| 250 | the frame in BATON. */ |
| 251 | |
| 252 | static CORE_ADDR |
| 253 | dwarf_expr_frame_cfa (void *baton) |
| 254 | { |
| 255 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
| 256 | |
| 257 | return dwarf2_frame_cfa (debaton->frame); |
| 258 | } |
| 259 | |
| 260 | /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for |
| 261 | the frame in BATON. */ |
| 262 | |
| 263 | static CORE_ADDR |
| 264 | dwarf_expr_frame_pc (void *baton) |
| 265 | { |
| 266 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
| 267 | |
| 268 | return get_frame_address_in_block (debaton->frame); |
| 269 | } |
| 270 | |
| 271 | /* Using the objfile specified in BATON, find the address for the |
| 272 | current thread's thread-local storage with offset OFFSET. */ |
| 273 | static CORE_ADDR |
| 274 | dwarf_expr_tls_address (void *baton, CORE_ADDR offset) |
| 275 | { |
| 276 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
| 277 | struct objfile *objfile = dwarf2_per_cu_objfile (debaton->per_cu); |
| 278 | |
| 279 | return target_translate_tls_address (objfile, offset); |
| 280 | } |
| 281 | |
| 282 | /* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in |
| 283 | current CU (as is PER_CU). State of the CTX is not affected by the |
| 284 | call and return. */ |
| 285 | |
| 286 | static void |
| 287 | per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset, |
| 288 | struct dwarf2_per_cu_data *per_cu, |
| 289 | CORE_ADDR (*get_frame_pc) (void *baton), |
| 290 | void *baton) |
| 291 | { |
| 292 | struct dwarf2_locexpr_baton block; |
| 293 | |
| 294 | block = dwarf2_fetch_die_location_block (die_offset, per_cu, |
| 295 | get_frame_pc, baton); |
| 296 | |
| 297 | /* DW_OP_call_ref is currently not supported. */ |
| 298 | gdb_assert (block.per_cu == per_cu); |
| 299 | |
| 300 | dwarf_expr_eval (ctx, block.data, block.size); |
| 301 | } |
| 302 | |
| 303 | /* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */ |
| 304 | |
| 305 | static void |
| 306 | dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset) |
| 307 | { |
| 308 | struct dwarf_expr_baton *debaton = ctx->baton; |
| 309 | |
| 310 | per_cu_dwarf_call (ctx, die_offset, debaton->per_cu, |
| 311 | ctx->funcs->get_frame_pc, ctx->baton); |
| 312 | } |
| 313 | |
| 314 | /* Callback function for dwarf2_evaluate_loc_desc. */ |
| 315 | |
| 316 | static struct type * |
| 317 | dwarf_expr_get_base_type (struct dwarf_expr_context *ctx, |
| 318 | cu_offset die_offset) |
| 319 | { |
| 320 | struct dwarf_expr_baton *debaton = ctx->baton; |
| 321 | |
| 322 | return dwarf2_get_die_type (die_offset, debaton->per_cu); |
| 323 | } |
| 324 | |
| 325 | /* See dwarf2loc.h. */ |
| 326 | |
| 327 | int entry_values_debug = 0; |
| 328 | |
| 329 | /* Helper to set entry_values_debug. */ |
| 330 | |
| 331 | static void |
| 332 | show_entry_values_debug (struct ui_file *file, int from_tty, |
| 333 | struct cmd_list_element *c, const char *value) |
| 334 | { |
| 335 | fprintf_filtered (file, |
| 336 | _("Entry values and tail call frames debugging is %s.\n"), |
| 337 | value); |
| 338 | } |
| 339 | |
| 340 | /* Find DW_TAG_GNU_call_site's DW_AT_GNU_call_site_target address. |
| 341 | CALLER_FRAME (for registers) can be NULL if it is not known. This function |
| 342 | always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */ |
| 343 | |
| 344 | static CORE_ADDR |
| 345 | call_site_to_target_addr (struct gdbarch *call_site_gdbarch, |
| 346 | struct call_site *call_site, |
| 347 | struct frame_info *caller_frame) |
| 348 | { |
| 349 | switch (FIELD_LOC_KIND (call_site->target)) |
| 350 | { |
| 351 | case FIELD_LOC_KIND_DWARF_BLOCK: |
| 352 | { |
| 353 | struct dwarf2_locexpr_baton *dwarf_block; |
| 354 | struct value *val; |
| 355 | struct type *caller_core_addr_type; |
| 356 | struct gdbarch *caller_arch; |
| 357 | |
| 358 | dwarf_block = FIELD_DWARF_BLOCK (call_site->target); |
| 359 | if (dwarf_block == NULL) |
| 360 | { |
| 361 | struct minimal_symbol *msym; |
| 362 | |
| 363 | msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| 364 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 365 | _("DW_AT_GNU_call_site_target is not specified " |
| 366 | "at %s in %s"), |
| 367 | paddress (call_site_gdbarch, call_site->pc), |
| 368 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 369 | |
| 370 | } |
| 371 | if (caller_frame == NULL) |
| 372 | { |
| 373 | struct minimal_symbol *msym; |
| 374 | |
| 375 | msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| 376 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 377 | _("DW_AT_GNU_call_site_target DWARF block resolving " |
| 378 | "requires known frame which is currently not " |
| 379 | "available at %s in %s"), |
| 380 | paddress (call_site_gdbarch, call_site->pc), |
| 381 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 382 | |
| 383 | } |
| 384 | caller_arch = get_frame_arch (caller_frame); |
| 385 | caller_core_addr_type = builtin_type (caller_arch)->builtin_func_ptr; |
| 386 | val = dwarf2_evaluate_loc_desc (caller_core_addr_type, caller_frame, |
| 387 | dwarf_block->data, dwarf_block->size, |
| 388 | dwarf_block->per_cu); |
| 389 | /* DW_AT_GNU_call_site_target is a DWARF expression, not a DWARF |
| 390 | location. */ |
| 391 | if (VALUE_LVAL (val) == lval_memory) |
| 392 | return value_address (val); |
| 393 | else |
| 394 | return value_as_address (val); |
| 395 | } |
| 396 | |
| 397 | case FIELD_LOC_KIND_PHYSNAME: |
| 398 | { |
| 399 | const char *physname; |
| 400 | struct minimal_symbol *msym; |
| 401 | |
| 402 | physname = FIELD_STATIC_PHYSNAME (call_site->target); |
| 403 | msym = lookup_minimal_symbol_text (physname, NULL); |
| 404 | if (msym == NULL) |
| 405 | { |
| 406 | msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| 407 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 408 | _("Cannot find function \"%s\" for a call site target " |
| 409 | "at %s in %s"), |
| 410 | physname, paddress (call_site_gdbarch, call_site->pc), |
| 411 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 412 | |
| 413 | } |
| 414 | return SYMBOL_VALUE_ADDRESS (msym); |
| 415 | } |
| 416 | |
| 417 | case FIELD_LOC_KIND_PHYSADDR: |
| 418 | return FIELD_STATIC_PHYSADDR (call_site->target); |
| 419 | |
| 420 | default: |
| 421 | internal_error (__FILE__, __LINE__, _("invalid call site target kind")); |
| 422 | } |
| 423 | } |
| 424 | |
| 425 | /* Convert function entry point exact address ADDR to the function which is |
| 426 | compliant with TAIL_CALL_LIST_COMPLETE condition. Throw |
| 427 | NO_ENTRY_VALUE_ERROR otherwise. */ |
| 428 | |
| 429 | static struct symbol * |
| 430 | func_addr_to_tail_call_list (struct gdbarch *gdbarch, CORE_ADDR addr) |
| 431 | { |
| 432 | struct symbol *sym = find_pc_function (addr); |
| 433 | struct type *type; |
| 434 | |
| 435 | if (sym == NULL || BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) != addr) |
| 436 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 437 | _("DW_TAG_GNU_call_site resolving failed to find function " |
| 438 | "name for address %s"), |
| 439 | paddress (gdbarch, addr)); |
| 440 | |
| 441 | type = SYMBOL_TYPE (sym); |
| 442 | gdb_assert (TYPE_CODE (type) == TYPE_CODE_FUNC); |
| 443 | gdb_assert (TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FUNC); |
| 444 | |
| 445 | return sym; |
| 446 | } |
| 447 | |
| 448 | /* Verify function with entry point exact address ADDR can never call itself |
| 449 | via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it |
| 450 | can call itself via tail calls. |
| 451 | |
| 452 | If a funtion can tail call itself its entry value based parameters are |
| 453 | unreliable. There is no verification whether the value of some/all |
| 454 | parameters is unchanged through the self tail call, we expect if there is |
| 455 | a self tail call all the parameters can be modified. */ |
| 456 | |
| 457 | static void |
| 458 | func_verify_no_selftailcall (struct gdbarch *gdbarch, CORE_ADDR verify_addr) |
| 459 | { |
| 460 | struct obstack addr_obstack; |
| 461 | struct cleanup *old_chain; |
| 462 | CORE_ADDR addr; |
| 463 | |
| 464 | /* Track here CORE_ADDRs which were already visited. */ |
| 465 | htab_t addr_hash; |
| 466 | |
| 467 | /* The verification is completely unordered. Track here function addresses |
| 468 | which still need to be iterated. */ |
| 469 | VEC (CORE_ADDR) *todo = NULL; |
| 470 | |
| 471 | obstack_init (&addr_obstack); |
| 472 | old_chain = make_cleanup_obstack_free (&addr_obstack); |
| 473 | addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL, |
| 474 | &addr_obstack, hashtab_obstack_allocate, |
| 475 | NULL); |
| 476 | make_cleanup_htab_delete (addr_hash); |
| 477 | |
| 478 | make_cleanup (VEC_cleanup (CORE_ADDR), &todo); |
| 479 | |
| 480 | VEC_safe_push (CORE_ADDR, todo, verify_addr); |
| 481 | while (!VEC_empty (CORE_ADDR, todo)) |
| 482 | { |
| 483 | struct symbol *func_sym; |
| 484 | struct call_site *call_site; |
| 485 | |
| 486 | addr = VEC_pop (CORE_ADDR, todo); |
| 487 | |
| 488 | func_sym = func_addr_to_tail_call_list (gdbarch, addr); |
| 489 | |
| 490 | for (call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym)); |
| 491 | call_site; call_site = call_site->tail_call_next) |
| 492 | { |
| 493 | CORE_ADDR target_addr; |
| 494 | void **slot; |
| 495 | |
| 496 | /* CALLER_FRAME with registers is not available for tail-call jumped |
| 497 | frames. */ |
| 498 | target_addr = call_site_to_target_addr (gdbarch, call_site, NULL); |
| 499 | |
| 500 | if (target_addr == verify_addr) |
| 501 | { |
| 502 | struct minimal_symbol *msym; |
| 503 | |
| 504 | msym = lookup_minimal_symbol_by_pc (verify_addr); |
| 505 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 506 | _("DW_OP_GNU_entry_value resolving has found " |
| 507 | "function \"%s\" at %s can call itself via tail " |
| 508 | "calls"), |
| 509 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym), |
| 510 | paddress (gdbarch, verify_addr)); |
| 511 | } |
| 512 | |
| 513 | slot = htab_find_slot (addr_hash, &target_addr, INSERT); |
| 514 | if (*slot == NULL) |
| 515 | { |
| 516 | *slot = obstack_copy (&addr_obstack, &target_addr, |
| 517 | sizeof (target_addr)); |
| 518 | VEC_safe_push (CORE_ADDR, todo, target_addr); |
| 519 | } |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | do_cleanups (old_chain); |
| 524 | } |
| 525 | |
| 526 | /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for |
| 527 | ENTRY_VALUES_DEBUG. */ |
| 528 | |
| 529 | static void |
| 530 | tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site) |
| 531 | { |
| 532 | CORE_ADDR addr = call_site->pc; |
| 533 | struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (addr - 1); |
| 534 | |
| 535 | fprintf_unfiltered (gdb_stdlog, " %s(%s)", paddress (gdbarch, addr), |
| 536 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 537 | |
| 538 | } |
| 539 | |
| 540 | /* vec.h needs single word type name, typedef it. */ |
| 541 | typedef struct call_site *call_sitep; |
| 542 | |
| 543 | /* Define VEC (call_sitep) functions. */ |
| 544 | DEF_VEC_P (call_sitep); |
| 545 | |
| 546 | /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP |
| 547 | only top callers and bottom callees which are present in both. GDBARCH is |
| 548 | used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are |
| 549 | no remaining possibilities to provide unambiguous non-trivial result. |
| 550 | RESULTP should point to NULL on the first (initialization) call. Caller is |
| 551 | responsible for xfree of any RESULTP data. */ |
| 552 | |
| 553 | static void |
| 554 | chain_candidate (struct gdbarch *gdbarch, struct call_site_chain **resultp, |
| 555 | VEC (call_sitep) *chain) |
| 556 | { |
| 557 | struct call_site_chain *result = *resultp; |
| 558 | long length = VEC_length (call_sitep, chain); |
| 559 | int callers, callees, idx; |
| 560 | |
| 561 | if (result == NULL) |
| 562 | { |
| 563 | /* Create the initial chain containing all the passed PCs. */ |
| 564 | |
| 565 | result = xmalloc (sizeof (*result) + sizeof (*result->call_site) |
| 566 | * (length - 1)); |
| 567 | result->length = length; |
| 568 | result->callers = result->callees = length; |
| 569 | memcpy (result->call_site, VEC_address (call_sitep, chain), |
| 570 | sizeof (*result->call_site) * length); |
| 571 | *resultp = result; |
| 572 | |
| 573 | if (entry_values_debug) |
| 574 | { |
| 575 | fprintf_unfiltered (gdb_stdlog, "tailcall: initial:"); |
| 576 | for (idx = 0; idx < length; idx++) |
| 577 | tailcall_dump (gdbarch, result->call_site[idx]); |
| 578 | fputc_unfiltered ('\n', gdb_stdlog); |
| 579 | } |
| 580 | |
| 581 | return; |
| 582 | } |
| 583 | |
| 584 | if (entry_values_debug) |
| 585 | { |
| 586 | fprintf_unfiltered (gdb_stdlog, "tailcall: compare:"); |
| 587 | for (idx = 0; idx < length; idx++) |
| 588 | tailcall_dump (gdbarch, VEC_index (call_sitep, chain, idx)); |
| 589 | fputc_unfiltered ('\n', gdb_stdlog); |
| 590 | } |
| 591 | |
| 592 | /* Intersect callers. */ |
| 593 | |
| 594 | callers = min (result->callers, length); |
| 595 | for (idx = 0; idx < callers; idx++) |
| 596 | if (result->call_site[idx] != VEC_index (call_sitep, chain, idx)) |
| 597 | { |
| 598 | result->callers = idx; |
| 599 | break; |
| 600 | } |
| 601 | |
| 602 | /* Intersect callees. */ |
| 603 | |
| 604 | callees = min (result->callees, length); |
| 605 | for (idx = 0; idx < callees; idx++) |
| 606 | if (result->call_site[result->length - 1 - idx] |
| 607 | != VEC_index (call_sitep, chain, length - 1 - idx)) |
| 608 | { |
| 609 | result->callees = idx; |
| 610 | break; |
| 611 | } |
| 612 | |
| 613 | if (entry_values_debug) |
| 614 | { |
| 615 | fprintf_unfiltered (gdb_stdlog, "tailcall: reduced:"); |
| 616 | for (idx = 0; idx < result->callers; idx++) |
| 617 | tailcall_dump (gdbarch, result->call_site[idx]); |
| 618 | fputs_unfiltered (" |", gdb_stdlog); |
| 619 | for (idx = 0; idx < result->callees; idx++) |
| 620 | tailcall_dump (gdbarch, result->call_site[result->length |
| 621 | - result->callees + idx]); |
| 622 | fputc_unfiltered ('\n', gdb_stdlog); |
| 623 | } |
| 624 | |
| 625 | if (result->callers == 0 && result->callees == 0) |
| 626 | { |
| 627 | /* There are no common callers or callees. It could be also a direct |
| 628 | call (which has length 0) with ambiguous possibility of an indirect |
| 629 | call - CALLERS == CALLEES == 0 is valid during the first allocation |
| 630 | but any subsequence processing of such entry means ambiguity. */ |
| 631 | xfree (result); |
| 632 | *resultp = NULL; |
| 633 | return; |
| 634 | } |
| 635 | |
| 636 | /* See call_site_find_chain_1 why there is no way to reach the bottom callee |
| 637 | PC again. In such case there must be two different code paths to reach |
| 638 | it, therefore some of the former determined intermediate PCs must differ |
| 639 | and the unambiguous chain gets shortened. */ |
| 640 | gdb_assert (result->callers + result->callees < result->length); |
| 641 | } |
| 642 | |
| 643 | /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the |
| 644 | assumed frames between them use GDBARCH. Use depth first search so we can |
| 645 | keep single CHAIN of call_site's back to CALLER_PC. Function recursion |
| 646 | would have needless GDB stack overhead. Caller is responsible for xfree of |
| 647 | the returned result. Any unreliability results in thrown |
| 648 | NO_ENTRY_VALUE_ERROR. */ |
| 649 | |
| 650 | static struct call_site_chain * |
| 651 | call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc, |
| 652 | CORE_ADDR callee_pc) |
| 653 | { |
| 654 | struct func_type *func_specific; |
| 655 | struct obstack addr_obstack; |
| 656 | struct cleanup *back_to_retval, *back_to_workdata; |
| 657 | struct call_site_chain *retval = NULL; |
| 658 | struct call_site *call_site; |
| 659 | |
| 660 | /* Mark CALL_SITEs so we do not visit the same ones twice. */ |
| 661 | htab_t addr_hash; |
| 662 | |
| 663 | /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's |
| 664 | call_site nor any possible call_site at CALLEE_PC's function is there. |
| 665 | Any CALL_SITE in CHAIN will be iterated to its siblings - via |
| 666 | TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */ |
| 667 | VEC (call_sitep) *chain = NULL; |
| 668 | |
| 669 | /* We are not interested in the specific PC inside the callee function. */ |
| 670 | callee_pc = get_pc_function_start (callee_pc); |
| 671 | if (callee_pc == 0) |
| 672 | throw_error (NO_ENTRY_VALUE_ERROR, _("Unable to find function for PC %s"), |
| 673 | paddress (gdbarch, callee_pc)); |
| 674 | |
| 675 | back_to_retval = make_cleanup (free_current_contents, &retval); |
| 676 | |
| 677 | obstack_init (&addr_obstack); |
| 678 | back_to_workdata = make_cleanup_obstack_free (&addr_obstack); |
| 679 | addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL, |
| 680 | &addr_obstack, hashtab_obstack_allocate, |
| 681 | NULL); |
| 682 | make_cleanup_htab_delete (addr_hash); |
| 683 | |
| 684 | make_cleanup (VEC_cleanup (call_sitep), &chain); |
| 685 | |
| 686 | /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site |
| 687 | at the target's function. All the possible tail call sites in the |
| 688 | target's function will get iterated as already pushed into CHAIN via their |
| 689 | TAIL_CALL_NEXT. */ |
| 690 | call_site = call_site_for_pc (gdbarch, caller_pc); |
| 691 | |
| 692 | while (call_site) |
| 693 | { |
| 694 | CORE_ADDR target_func_addr; |
| 695 | struct call_site *target_call_site; |
| 696 | |
| 697 | /* CALLER_FRAME with registers is not available for tail-call jumped |
| 698 | frames. */ |
| 699 | target_func_addr = call_site_to_target_addr (gdbarch, call_site, NULL); |
| 700 | |
| 701 | if (target_func_addr == callee_pc) |
| 702 | { |
| 703 | chain_candidate (gdbarch, &retval, chain); |
| 704 | if (retval == NULL) |
| 705 | break; |
| 706 | |
| 707 | /* There is no way to reach CALLEE_PC again as we would prevent |
| 708 | entering it twice as being already marked in ADDR_HASH. */ |
| 709 | target_call_site = NULL; |
| 710 | } |
| 711 | else |
| 712 | { |
| 713 | struct symbol *target_func; |
| 714 | |
| 715 | target_func = func_addr_to_tail_call_list (gdbarch, target_func_addr); |
| 716 | target_call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func)); |
| 717 | } |
| 718 | |
| 719 | do |
| 720 | { |
| 721 | /* Attempt to visit TARGET_CALL_SITE. */ |
| 722 | |
| 723 | if (target_call_site) |
| 724 | { |
| 725 | void **slot; |
| 726 | |
| 727 | slot = htab_find_slot (addr_hash, &target_call_site->pc, INSERT); |
| 728 | if (*slot == NULL) |
| 729 | { |
| 730 | /* Successfully entered TARGET_CALL_SITE. */ |
| 731 | |
| 732 | *slot = &target_call_site->pc; |
| 733 | VEC_safe_push (call_sitep, chain, target_call_site); |
| 734 | break; |
| 735 | } |
| 736 | } |
| 737 | |
| 738 | /* Backtrack (without revisiting the originating call_site). Try the |
| 739 | callers's sibling; if there isn't any try the callers's callers's |
| 740 | sibling etc. */ |
| 741 | |
| 742 | target_call_site = NULL; |
| 743 | while (!VEC_empty (call_sitep, chain)) |
| 744 | { |
| 745 | call_site = VEC_pop (call_sitep, chain); |
| 746 | |
| 747 | gdb_assert (htab_find_slot (addr_hash, &call_site->pc, |
| 748 | NO_INSERT) != NULL); |
| 749 | htab_remove_elt (addr_hash, &call_site->pc); |
| 750 | |
| 751 | target_call_site = call_site->tail_call_next; |
| 752 | if (target_call_site) |
| 753 | break; |
| 754 | } |
| 755 | } |
| 756 | while (target_call_site); |
| 757 | |
| 758 | if (VEC_empty (call_sitep, chain)) |
| 759 | call_site = NULL; |
| 760 | else |
| 761 | call_site = VEC_last (call_sitep, chain); |
| 762 | } |
| 763 | |
| 764 | if (retval == NULL) |
| 765 | { |
| 766 | struct minimal_symbol *msym_caller, *msym_callee; |
| 767 | |
| 768 | msym_caller = lookup_minimal_symbol_by_pc (caller_pc); |
| 769 | msym_callee = lookup_minimal_symbol_by_pc (callee_pc); |
| 770 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 771 | _("There are no unambiguously determinable intermediate " |
| 772 | "callers or callees between caller function \"%s\" at %s " |
| 773 | "and callee function \"%s\" at %s"), |
| 774 | (msym_caller == NULL |
| 775 | ? "???" : SYMBOL_PRINT_NAME (msym_caller)), |
| 776 | paddress (gdbarch, caller_pc), |
| 777 | (msym_callee == NULL |
| 778 | ? "???" : SYMBOL_PRINT_NAME (msym_callee)), |
| 779 | paddress (gdbarch, callee_pc)); |
| 780 | } |
| 781 | |
| 782 | do_cleanups (back_to_workdata); |
| 783 | discard_cleanups (back_to_retval); |
| 784 | return retval; |
| 785 | } |
| 786 | |
| 787 | /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the |
| 788 | assumed frames between them use GDBARCH. If valid call_site_chain cannot be |
| 789 | constructed return NULL. Caller is responsible for xfree of the returned |
| 790 | result. */ |
| 791 | |
| 792 | struct call_site_chain * |
| 793 | call_site_find_chain (struct gdbarch *gdbarch, CORE_ADDR caller_pc, |
| 794 | CORE_ADDR callee_pc) |
| 795 | { |
| 796 | volatile struct gdb_exception e; |
| 797 | struct call_site_chain *retval = NULL; |
| 798 | |
| 799 | TRY_CATCH (e, RETURN_MASK_ERROR) |
| 800 | { |
| 801 | retval = call_site_find_chain_1 (gdbarch, caller_pc, callee_pc); |
| 802 | } |
| 803 | if (e.reason < 0) |
| 804 | { |
| 805 | if (e.error == NO_ENTRY_VALUE_ERROR) |
| 806 | { |
| 807 | if (entry_values_debug) |
| 808 | exception_print (gdb_stdout, e); |
| 809 | |
| 810 | return NULL; |
| 811 | } |
| 812 | else |
| 813 | throw_exception (e); |
| 814 | } |
| 815 | return retval; |
| 816 | } |
| 817 | |
| 818 | /* Fetch call_site_parameter from caller matching the parameters. FRAME is for |
| 819 | callee. See DWARF_REG and FB_OFFSET description at struct |
| 820 | dwarf_expr_context_funcs->push_dwarf_reg_entry_value. |
| 821 | |
| 822 | Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR |
| 823 | otherwise. */ |
| 824 | |
| 825 | static struct call_site_parameter * |
| 826 | dwarf_expr_reg_to_entry_parameter (struct frame_info *frame, int dwarf_reg, |
| 827 | CORE_ADDR fb_offset, |
| 828 | struct dwarf2_per_cu_data **per_cu_return) |
| 829 | { |
| 830 | CORE_ADDR func_addr = get_frame_func (frame); |
| 831 | CORE_ADDR caller_pc; |
| 832 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 833 | struct frame_info *caller_frame = get_prev_frame (frame); |
| 834 | struct call_site *call_site; |
| 835 | int iparams; |
| 836 | struct value *val; |
| 837 | struct dwarf2_locexpr_baton *dwarf_block; |
| 838 | /* Initialize it just to avoid a GCC false warning. */ |
| 839 | struct call_site_parameter *parameter = NULL; |
| 840 | CORE_ADDR target_addr; |
| 841 | |
| 842 | if (gdbarch != frame_unwind_arch (frame)) |
| 843 | { |
| 844 | struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr); |
| 845 | struct gdbarch *caller_gdbarch = frame_unwind_arch (frame); |
| 846 | |
| 847 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 848 | _("DW_OP_GNU_entry_value resolving callee gdbarch %s " |
| 849 | "(of %s (%s)) does not match caller gdbarch %s"), |
| 850 | gdbarch_bfd_arch_info (gdbarch)->printable_name, |
| 851 | paddress (gdbarch, func_addr), |
| 852 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym), |
| 853 | gdbarch_bfd_arch_info (caller_gdbarch)->printable_name); |
| 854 | } |
| 855 | |
| 856 | if (caller_frame == NULL) |
| 857 | { |
| 858 | struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr); |
| 859 | |
| 860 | throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_GNU_entry_value resolving " |
| 861 | "requires caller of %s (%s)"), |
| 862 | paddress (gdbarch, func_addr), |
| 863 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 864 | } |
| 865 | caller_pc = get_frame_pc (caller_frame); |
| 866 | call_site = call_site_for_pc (gdbarch, caller_pc); |
| 867 | |
| 868 | target_addr = call_site_to_target_addr (gdbarch, call_site, caller_frame); |
| 869 | if (target_addr != func_addr) |
| 870 | { |
| 871 | struct minimal_symbol *target_msym, *func_msym; |
| 872 | |
| 873 | target_msym = lookup_minimal_symbol_by_pc (target_addr); |
| 874 | func_msym = lookup_minimal_symbol_by_pc (func_addr); |
| 875 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 876 | _("DW_OP_GNU_entry_value resolving expects callee %s at %s " |
| 877 | "but the called frame is for %s at %s"), |
| 878 | (target_msym == NULL ? "???" |
| 879 | : SYMBOL_PRINT_NAME (target_msym)), |
| 880 | paddress (gdbarch, target_addr), |
| 881 | func_msym == NULL ? "???" : SYMBOL_PRINT_NAME (func_msym), |
| 882 | paddress (gdbarch, func_addr)); |
| 883 | } |
| 884 | |
| 885 | /* No entry value based parameters would be reliable if this function can |
| 886 | call itself via tail calls. */ |
| 887 | func_verify_no_selftailcall (gdbarch, func_addr); |
| 888 | |
| 889 | for (iparams = 0; iparams < call_site->parameter_count; iparams++) |
| 890 | { |
| 891 | parameter = &call_site->parameter[iparams]; |
| 892 | if (parameter->dwarf_reg == -1 && dwarf_reg == -1) |
| 893 | { |
| 894 | if (parameter->fb_offset == fb_offset) |
| 895 | break; |
| 896 | } |
| 897 | else if (parameter->dwarf_reg == dwarf_reg) |
| 898 | break; |
| 899 | } |
| 900 | if (iparams == call_site->parameter_count) |
| 901 | { |
| 902 | struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (caller_pc); |
| 903 | |
| 904 | /* DW_TAG_GNU_call_site_parameter will be missing just if GCC could not |
| 905 | determine its value. */ |
| 906 | throw_error (NO_ENTRY_VALUE_ERROR, _("Cannot find matching parameter " |
| 907 | "at DW_TAG_GNU_call_site %s at %s"), |
| 908 | paddress (gdbarch, caller_pc), |
| 909 | msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); |
| 910 | } |
| 911 | |
| 912 | *per_cu_return = call_site->per_cu; |
| 913 | return parameter; |
| 914 | } |
| 915 | |
| 916 | /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return |
| 917 | the normal DW_AT_GNU_call_site_value block. Otherwise return the |
| 918 | DW_AT_GNU_call_site_data_value (dereferenced) block. |
| 919 | |
| 920 | TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned |
| 921 | struct value. |
| 922 | |
| 923 | Function always returns non-NULL, non-optimized out value. It throws |
| 924 | NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */ |
| 925 | |
| 926 | static struct value * |
| 927 | dwarf_entry_parameter_to_value (struct call_site_parameter *parameter, |
| 928 | CORE_ADDR deref_size, struct type *type, |
| 929 | struct frame_info *caller_frame, |
| 930 | struct dwarf2_per_cu_data *per_cu) |
| 931 | { |
| 932 | const gdb_byte *data_src; |
| 933 | gdb_byte *data; |
| 934 | size_t size; |
| 935 | |
| 936 | data_src = deref_size == -1 ? parameter->value : parameter->data_value; |
| 937 | size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; |
| 938 | |
| 939 | /* DEREF_SIZE size is not verified here. */ |
| 940 | if (data_src == NULL) |
| 941 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 942 | _("Cannot resolve DW_AT_GNU_call_site_data_value")); |
| 943 | |
| 944 | /* DW_AT_GNU_call_site_value is a DWARF expression, not a DWARF |
| 945 | location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from |
| 946 | DWARF block. */ |
| 947 | data = alloca (size + 1); |
| 948 | memcpy (data, data_src, size); |
| 949 | data[size] = DW_OP_stack_value; |
| 950 | |
| 951 | return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu); |
| 952 | } |
| 953 | |
| 954 | /* Execute call_site_parameter's DWARF block matching DEREF_SIZE for caller of |
| 955 | the CTX's frame. CTX must be of dwarf_expr_ctx_funcs kind. See DWARF_REG |
| 956 | and FB_OFFSET description at struct |
| 957 | dwarf_expr_context_funcs->push_dwarf_reg_entry_value. |
| 958 | |
| 959 | The CTX caller can be from a different CU - per_cu_dwarf_call implementation |
| 960 | can be more simple as it does not support cross-CU DWARF executions. */ |
| 961 | |
| 962 | static void |
| 963 | dwarf_expr_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx, |
| 964 | int dwarf_reg, CORE_ADDR fb_offset, |
| 965 | int deref_size) |
| 966 | { |
| 967 | struct dwarf_expr_baton *debaton; |
| 968 | struct frame_info *frame, *caller_frame; |
| 969 | struct dwarf2_per_cu_data *caller_per_cu; |
| 970 | struct dwarf_expr_baton baton_local; |
| 971 | struct dwarf_expr_context saved_ctx; |
| 972 | struct call_site_parameter *parameter; |
| 973 | const gdb_byte *data_src; |
| 974 | size_t size; |
| 975 | |
| 976 | gdb_assert (ctx->funcs == &dwarf_expr_ctx_funcs); |
| 977 | debaton = ctx->baton; |
| 978 | frame = debaton->frame; |
| 979 | caller_frame = get_prev_frame (frame); |
| 980 | |
| 981 | parameter = dwarf_expr_reg_to_entry_parameter (frame, dwarf_reg, fb_offset, |
| 982 | &caller_per_cu); |
| 983 | data_src = deref_size == -1 ? parameter->value : parameter->data_value; |
| 984 | size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; |
| 985 | |
| 986 | /* DEREF_SIZE size is not verified here. */ |
| 987 | if (data_src == NULL) |
| 988 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 989 | _("Cannot resolve DW_AT_GNU_call_site_data_value")); |
| 990 | |
| 991 | baton_local.frame = caller_frame; |
| 992 | baton_local.per_cu = caller_per_cu; |
| 993 | |
| 994 | saved_ctx.gdbarch = ctx->gdbarch; |
| 995 | saved_ctx.addr_size = ctx->addr_size; |
| 996 | saved_ctx.offset = ctx->offset; |
| 997 | saved_ctx.baton = ctx->baton; |
| 998 | ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (baton_local.per_cu)); |
| 999 | ctx->addr_size = dwarf2_per_cu_addr_size (baton_local.per_cu); |
| 1000 | ctx->offset = dwarf2_per_cu_text_offset (baton_local.per_cu); |
| 1001 | ctx->baton = &baton_local; |
| 1002 | |
| 1003 | dwarf_expr_eval (ctx, data_src, size); |
| 1004 | |
| 1005 | ctx->gdbarch = saved_ctx.gdbarch; |
| 1006 | ctx->addr_size = saved_ctx.addr_size; |
| 1007 | ctx->offset = saved_ctx.offset; |
| 1008 | ctx->baton = saved_ctx.baton; |
| 1009 | } |
| 1010 | |
| 1011 | /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform |
| 1012 | the indirect method on it, that is use its stored target value, the sole |
| 1013 | purpose of entry_data_value_funcs.. */ |
| 1014 | |
| 1015 | static struct value * |
| 1016 | entry_data_value_coerce_ref (const struct value *value) |
| 1017 | { |
| 1018 | struct type *checked_type = check_typedef (value_type (value)); |
| 1019 | struct value *target_val; |
| 1020 | |
| 1021 | if (TYPE_CODE (checked_type) != TYPE_CODE_REF) |
| 1022 | return NULL; |
| 1023 | |
| 1024 | target_val = value_computed_closure (value); |
| 1025 | value_incref (target_val); |
| 1026 | return target_val; |
| 1027 | } |
| 1028 | |
| 1029 | /* Implement copy_closure. */ |
| 1030 | |
| 1031 | static void * |
| 1032 | entry_data_value_copy_closure (const struct value *v) |
| 1033 | { |
| 1034 | struct value *target_val = value_computed_closure (v); |
| 1035 | |
| 1036 | value_incref (target_val); |
| 1037 | return target_val; |
| 1038 | } |
| 1039 | |
| 1040 | /* Implement free_closure. */ |
| 1041 | |
| 1042 | static void |
| 1043 | entry_data_value_free_closure (struct value *v) |
| 1044 | { |
| 1045 | struct value *target_val = value_computed_closure (v); |
| 1046 | |
| 1047 | value_free (target_val); |
| 1048 | } |
| 1049 | |
| 1050 | /* Vector for methods for an entry value reference where the referenced value |
| 1051 | is stored in the caller. On the first dereference use |
| 1052 | DW_AT_GNU_call_site_data_value in the caller. */ |
| 1053 | |
| 1054 | static const struct lval_funcs entry_data_value_funcs = |
| 1055 | { |
| 1056 | NULL, /* read */ |
| 1057 | NULL, /* write */ |
| 1058 | NULL, /* check_validity */ |
| 1059 | NULL, /* check_any_valid */ |
| 1060 | NULL, /* indirect */ |
| 1061 | entry_data_value_coerce_ref, |
| 1062 | NULL, /* check_synthetic_pointer */ |
| 1063 | entry_data_value_copy_closure, |
| 1064 | entry_data_value_free_closure |
| 1065 | }; |
| 1066 | |
| 1067 | /* Read parameter of TYPE at (callee) FRAME's function entry. DWARF_REG and |
| 1068 | FB_OFFSET are used to match DW_AT_location at the caller's |
| 1069 | DW_TAG_GNU_call_site_parameter. See DWARF_REG and FB_OFFSET description at |
| 1070 | struct dwarf_expr_context_funcs->push_dwarf_reg_entry_value. |
| 1071 | |
| 1072 | Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it |
| 1073 | cannot resolve the parameter for any reason. */ |
| 1074 | |
| 1075 | static struct value * |
| 1076 | value_of_dwarf_reg_entry (struct type *type, struct frame_info *frame, |
| 1077 | int dwarf_reg, CORE_ADDR fb_offset) |
| 1078 | { |
| 1079 | struct type *checked_type = check_typedef (type); |
| 1080 | struct type *target_type = TYPE_TARGET_TYPE (checked_type); |
| 1081 | struct frame_info *caller_frame = get_prev_frame (frame); |
| 1082 | struct value *outer_val, *target_val, *val; |
| 1083 | struct call_site_parameter *parameter; |
| 1084 | struct dwarf2_per_cu_data *caller_per_cu; |
| 1085 | CORE_ADDR addr; |
| 1086 | |
| 1087 | parameter = dwarf_expr_reg_to_entry_parameter (frame, dwarf_reg, fb_offset, |
| 1088 | &caller_per_cu); |
| 1089 | |
| 1090 | outer_val = dwarf_entry_parameter_to_value (parameter, -1 /* deref_size */, |
| 1091 | type, caller_frame, |
| 1092 | caller_per_cu); |
| 1093 | |
| 1094 | /* Check if DW_AT_GNU_call_site_data_value cannot be used. If it should be |
| 1095 | used and it is not available do not fall back to OUTER_VAL - dereferencing |
| 1096 | TYPE_CODE_REF with non-entry data value would give current value - not the |
| 1097 | entry value. */ |
| 1098 | |
| 1099 | if (TYPE_CODE (checked_type) != TYPE_CODE_REF |
| 1100 | || TYPE_TARGET_TYPE (checked_type) == NULL) |
| 1101 | return outer_val; |
| 1102 | |
| 1103 | target_val = dwarf_entry_parameter_to_value (parameter, |
| 1104 | TYPE_LENGTH (target_type), |
| 1105 | target_type, caller_frame, |
| 1106 | caller_per_cu); |
| 1107 | |
| 1108 | /* value_as_address dereferences TYPE_CODE_REF. */ |
| 1109 | addr = extract_typed_address (value_contents (outer_val), checked_type); |
| 1110 | |
| 1111 | /* The target entry value has artificial address of the entry value |
| 1112 | reference. */ |
| 1113 | VALUE_LVAL (target_val) = lval_memory; |
| 1114 | set_value_address (target_val, addr); |
| 1115 | |
| 1116 | release_value (target_val); |
| 1117 | val = allocate_computed_value (type, &entry_data_value_funcs, |
| 1118 | target_val /* closure */); |
| 1119 | |
| 1120 | /* Copy the referencing pointer to the new computed value. */ |
| 1121 | memcpy (value_contents_raw (val), value_contents_raw (outer_val), |
| 1122 | TYPE_LENGTH (checked_type)); |
| 1123 | set_value_lazy (val, 0); |
| 1124 | |
| 1125 | return val; |
| 1126 | } |
| 1127 | |
| 1128 | /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and |
| 1129 | SIZE are DWARF block used to match DW_AT_location at the caller's |
| 1130 | DW_TAG_GNU_call_site_parameter. |
| 1131 | |
| 1132 | Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it |
| 1133 | cannot resolve the parameter for any reason. */ |
| 1134 | |
| 1135 | static struct value * |
| 1136 | value_of_dwarf_block_entry (struct type *type, struct frame_info *frame, |
| 1137 | const gdb_byte *block, size_t block_len) |
| 1138 | { |
| 1139 | int dwarf_reg; |
| 1140 | CORE_ADDR fb_offset; |
| 1141 | |
| 1142 | dwarf_reg = dwarf_block_to_dwarf_reg (block, block + block_len); |
| 1143 | if (dwarf_reg != -1) |
| 1144 | return value_of_dwarf_reg_entry (type, frame, dwarf_reg, 0 /* unused */); |
| 1145 | |
| 1146 | if (dwarf_block_to_fb_offset (block, block + block_len, &fb_offset)) |
| 1147 | return value_of_dwarf_reg_entry (type, frame, -1, fb_offset); |
| 1148 | |
| 1149 | /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message |
| 1150 | suppressed during normal operation. The expression can be arbitrary if |
| 1151 | there is no caller-callee entry value binding expected. */ |
| 1152 | throw_error (NO_ENTRY_VALUE_ERROR, |
| 1153 | _("DWARF-2 expression error: DW_OP_GNU_entry_value is supported " |
| 1154 | "only for single DW_OP_reg* or for DW_OP_fbreg(*)")); |
| 1155 | } |
| 1156 | |
| 1157 | struct piece_closure |
| 1158 | { |
| 1159 | /* Reference count. */ |
| 1160 | int refc; |
| 1161 | |
| 1162 | /* The CU from which this closure's expression came. */ |
| 1163 | struct dwarf2_per_cu_data *per_cu; |
| 1164 | |
| 1165 | /* The number of pieces used to describe this variable. */ |
| 1166 | int n_pieces; |
| 1167 | |
| 1168 | /* The target address size, used only for DWARF_VALUE_STACK. */ |
| 1169 | int addr_size; |
| 1170 | |
| 1171 | /* The pieces themselves. */ |
| 1172 | struct dwarf_expr_piece *pieces; |
| 1173 | }; |
| 1174 | |
| 1175 | /* Allocate a closure for a value formed from separately-described |
| 1176 | PIECES. */ |
| 1177 | |
| 1178 | static struct piece_closure * |
| 1179 | allocate_piece_closure (struct dwarf2_per_cu_data *per_cu, |
| 1180 | int n_pieces, struct dwarf_expr_piece *pieces, |
| 1181 | int addr_size) |
| 1182 | { |
| 1183 | struct piece_closure *c = XZALLOC (struct piece_closure); |
| 1184 | int i; |
| 1185 | |
| 1186 | c->refc = 1; |
| 1187 | c->per_cu = per_cu; |
| 1188 | c->n_pieces = n_pieces; |
| 1189 | c->addr_size = addr_size; |
| 1190 | c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece); |
| 1191 | |
| 1192 | memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece)); |
| 1193 | for (i = 0; i < n_pieces; ++i) |
| 1194 | if (c->pieces[i].location == DWARF_VALUE_STACK) |
| 1195 | value_incref (c->pieces[i].v.value); |
| 1196 | |
| 1197 | return c; |
| 1198 | } |
| 1199 | |
| 1200 | /* The lowest-level function to extract bits from a byte buffer. |
| 1201 | SOURCE is the buffer. It is updated if we read to the end of a |
| 1202 | byte. |
| 1203 | SOURCE_OFFSET_BITS is the offset of the first bit to read. It is |
| 1204 | updated to reflect the number of bits actually read. |
| 1205 | NBITS is the number of bits we want to read. It is updated to |
| 1206 | reflect the number of bits actually read. This function may read |
| 1207 | fewer bits. |
| 1208 | BITS_BIG_ENDIAN is taken directly from gdbarch. |
| 1209 | This function returns the extracted bits. */ |
| 1210 | |
| 1211 | static unsigned int |
| 1212 | extract_bits_primitive (const gdb_byte **source, |
| 1213 | unsigned int *source_offset_bits, |
| 1214 | int *nbits, int bits_big_endian) |
| 1215 | { |
| 1216 | unsigned int avail, mask, datum; |
| 1217 | |
| 1218 | gdb_assert (*source_offset_bits < 8); |
| 1219 | |
| 1220 | avail = 8 - *source_offset_bits; |
| 1221 | if (avail > *nbits) |
| 1222 | avail = *nbits; |
| 1223 | |
| 1224 | mask = (1 << avail) - 1; |
| 1225 | datum = **source; |
| 1226 | if (bits_big_endian) |
| 1227 | datum >>= 8 - (*source_offset_bits + *nbits); |
| 1228 | else |
| 1229 | datum >>= *source_offset_bits; |
| 1230 | datum &= mask; |
| 1231 | |
| 1232 | *nbits -= avail; |
| 1233 | *source_offset_bits += avail; |
| 1234 | if (*source_offset_bits >= 8) |
| 1235 | { |
| 1236 | *source_offset_bits -= 8; |
| 1237 | ++*source; |
| 1238 | } |
| 1239 | |
| 1240 | return datum; |
| 1241 | } |
| 1242 | |
| 1243 | /* Extract some bits from a source buffer and move forward in the |
| 1244 | buffer. |
| 1245 | |
| 1246 | SOURCE is the source buffer. It is updated as bytes are read. |
| 1247 | SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as |
| 1248 | bits are read. |
| 1249 | NBITS is the number of bits to read. |
| 1250 | BITS_BIG_ENDIAN is taken directly from gdbarch. |
| 1251 | |
| 1252 | This function returns the bits that were read. */ |
| 1253 | |
| 1254 | static unsigned int |
| 1255 | extract_bits (const gdb_byte **source, unsigned int *source_offset_bits, |
| 1256 | int nbits, int bits_big_endian) |
| 1257 | { |
| 1258 | unsigned int datum; |
| 1259 | |
| 1260 | gdb_assert (nbits > 0 && nbits <= 8); |
| 1261 | |
| 1262 | datum = extract_bits_primitive (source, source_offset_bits, &nbits, |
| 1263 | bits_big_endian); |
| 1264 | if (nbits > 0) |
| 1265 | { |
| 1266 | unsigned int more; |
| 1267 | |
| 1268 | more = extract_bits_primitive (source, source_offset_bits, &nbits, |
| 1269 | bits_big_endian); |
| 1270 | if (bits_big_endian) |
| 1271 | datum <<= nbits; |
| 1272 | else |
| 1273 | more <<= nbits; |
| 1274 | datum |= more; |
| 1275 | } |
| 1276 | |
| 1277 | return datum; |
| 1278 | } |
| 1279 | |
| 1280 | /* Write some bits into a buffer and move forward in the buffer. |
| 1281 | |
| 1282 | DATUM is the bits to write. The low-order bits of DATUM are used. |
| 1283 | DEST is the destination buffer. It is updated as bytes are |
| 1284 | written. |
| 1285 | DEST_OFFSET_BITS is the bit offset in DEST at which writing is |
| 1286 | done. |
| 1287 | NBITS is the number of valid bits in DATUM. |
| 1288 | BITS_BIG_ENDIAN is taken directly from gdbarch. */ |
| 1289 | |
| 1290 | static void |
| 1291 | insert_bits (unsigned int datum, |
| 1292 | gdb_byte *dest, unsigned int dest_offset_bits, |
| 1293 | int nbits, int bits_big_endian) |
| 1294 | { |
| 1295 | unsigned int mask; |
| 1296 | |
| 1297 | gdb_assert (dest_offset_bits + nbits <= 8); |
| 1298 | |
| 1299 | mask = (1 << nbits) - 1; |
| 1300 | if (bits_big_endian) |
| 1301 | { |
| 1302 | datum <<= 8 - (dest_offset_bits + nbits); |
| 1303 | mask <<= 8 - (dest_offset_bits + nbits); |
| 1304 | } |
| 1305 | else |
| 1306 | { |
| 1307 | datum <<= dest_offset_bits; |
| 1308 | mask <<= dest_offset_bits; |
| 1309 | } |
| 1310 | |
| 1311 | gdb_assert ((datum & ~mask) == 0); |
| 1312 | |
| 1313 | *dest = (*dest & ~mask) | datum; |
| 1314 | } |
| 1315 | |
| 1316 | /* Copy bits from a source to a destination. |
| 1317 | |
| 1318 | DEST is where the bits should be written. |
| 1319 | DEST_OFFSET_BITS is the bit offset into DEST. |
| 1320 | SOURCE is the source of bits. |
| 1321 | SOURCE_OFFSET_BITS is the bit offset into SOURCE. |
| 1322 | BIT_COUNT is the number of bits to copy. |
| 1323 | BITS_BIG_ENDIAN is taken directly from gdbarch. */ |
| 1324 | |
| 1325 | static void |
| 1326 | copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits, |
| 1327 | const gdb_byte *source, unsigned int source_offset_bits, |
| 1328 | unsigned int bit_count, |
| 1329 | int bits_big_endian) |
| 1330 | { |
| 1331 | unsigned int dest_avail; |
| 1332 | int datum; |
| 1333 | |
| 1334 | /* Reduce everything to byte-size pieces. */ |
| 1335 | dest += dest_offset_bits / 8; |
| 1336 | dest_offset_bits %= 8; |
| 1337 | source += source_offset_bits / 8; |
| 1338 | source_offset_bits %= 8; |
| 1339 | |
| 1340 | dest_avail = 8 - dest_offset_bits % 8; |
| 1341 | |
| 1342 | /* See if we can fill the first destination byte. */ |
| 1343 | if (dest_avail < bit_count) |
| 1344 | { |
| 1345 | datum = extract_bits (&source, &source_offset_bits, dest_avail, |
| 1346 | bits_big_endian); |
| 1347 | insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian); |
| 1348 | ++dest; |
| 1349 | dest_offset_bits = 0; |
| 1350 | bit_count -= dest_avail; |
| 1351 | } |
| 1352 | |
| 1353 | /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer |
| 1354 | than 8 bits remaining. */ |
| 1355 | gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8); |
| 1356 | for (; bit_count >= 8; bit_count -= 8) |
| 1357 | { |
| 1358 | datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian); |
| 1359 | *dest++ = (gdb_byte) datum; |
| 1360 | } |
| 1361 | |
| 1362 | /* Finally, we may have a few leftover bits. */ |
| 1363 | gdb_assert (bit_count <= 8 - dest_offset_bits % 8); |
| 1364 | if (bit_count > 0) |
| 1365 | { |
| 1366 | datum = extract_bits (&source, &source_offset_bits, bit_count, |
| 1367 | bits_big_endian); |
| 1368 | insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian); |
| 1369 | } |
| 1370 | } |
| 1371 | |
| 1372 | static void |
| 1373 | read_pieced_value (struct value *v) |
| 1374 | { |
| 1375 | int i; |
| 1376 | long offset = 0; |
| 1377 | ULONGEST bits_to_skip; |
| 1378 | gdb_byte *contents; |
| 1379 | struct piece_closure *c |
| 1380 | = (struct piece_closure *) value_computed_closure (v); |
| 1381 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v)); |
| 1382 | size_t type_len; |
| 1383 | size_t buffer_size = 0; |
| 1384 | char *buffer = NULL; |
| 1385 | struct cleanup *cleanup; |
| 1386 | int bits_big_endian |
| 1387 | = gdbarch_bits_big_endian (get_type_arch (value_type (v))); |
| 1388 | |
| 1389 | if (value_type (v) != value_enclosing_type (v)) |
| 1390 | internal_error (__FILE__, __LINE__, |
| 1391 | _("Should not be able to create a lazy value with " |
| 1392 | "an enclosing type")); |
| 1393 | |
| 1394 | cleanup = make_cleanup (free_current_contents, &buffer); |
| 1395 | |
| 1396 | contents = value_contents_raw (v); |
| 1397 | bits_to_skip = 8 * value_offset (v); |
| 1398 | if (value_bitsize (v)) |
| 1399 | { |
| 1400 | bits_to_skip += value_bitpos (v); |
| 1401 | type_len = value_bitsize (v); |
| 1402 | } |
| 1403 | else |
| 1404 | type_len = 8 * TYPE_LENGTH (value_type (v)); |
| 1405 | |
| 1406 | for (i = 0; i < c->n_pieces && offset < type_len; i++) |
| 1407 | { |
| 1408 | struct dwarf_expr_piece *p = &c->pieces[i]; |
| 1409 | size_t this_size, this_size_bits; |
| 1410 | long dest_offset_bits, source_offset_bits, source_offset; |
| 1411 | const gdb_byte *intermediate_buffer; |
| 1412 | |
| 1413 | /* Compute size, source, and destination offsets for copying, in |
| 1414 | bits. */ |
| 1415 | this_size_bits = p->size; |
| 1416 | if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) |
| 1417 | { |
| 1418 | bits_to_skip -= this_size_bits; |
| 1419 | continue; |
| 1420 | } |
| 1421 | if (this_size_bits > type_len - offset) |
| 1422 | this_size_bits = type_len - offset; |
| 1423 | if (bits_to_skip > 0) |
| 1424 | { |
| 1425 | dest_offset_bits = 0; |
| 1426 | source_offset_bits = bits_to_skip; |
| 1427 | this_size_bits -= bits_to_skip; |
| 1428 | bits_to_skip = 0; |
| 1429 | } |
| 1430 | else |
| 1431 | { |
| 1432 | dest_offset_bits = offset; |
| 1433 | source_offset_bits = 0; |
| 1434 | } |
| 1435 | |
| 1436 | this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; |
| 1437 | source_offset = source_offset_bits / 8; |
| 1438 | if (buffer_size < this_size) |
| 1439 | { |
| 1440 | buffer_size = this_size; |
| 1441 | buffer = xrealloc (buffer, buffer_size); |
| 1442 | } |
| 1443 | intermediate_buffer = buffer; |
| 1444 | |
| 1445 | /* Copy from the source to DEST_BUFFER. */ |
| 1446 | switch (p->location) |
| 1447 | { |
| 1448 | case DWARF_VALUE_REGISTER: |
| 1449 | { |
| 1450 | struct gdbarch *arch = get_frame_arch (frame); |
| 1451 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno); |
| 1452 | int reg_offset = source_offset; |
| 1453 | |
| 1454 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG |
| 1455 | && this_size < register_size (arch, gdb_regnum)) |
| 1456 | { |
| 1457 | /* Big-endian, and we want less than full size. */ |
| 1458 | reg_offset = register_size (arch, gdb_regnum) - this_size; |
| 1459 | /* We want the lower-order THIS_SIZE_BITS of the bytes |
| 1460 | we extract from the register. */ |
| 1461 | source_offset_bits += 8 * this_size - this_size_bits; |
| 1462 | } |
| 1463 | |
| 1464 | if (gdb_regnum != -1) |
| 1465 | { |
| 1466 | int optim, unavail; |
| 1467 | |
| 1468 | if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| 1469 | this_size, buffer, |
| 1470 | &optim, &unavail)) |
| 1471 | { |
| 1472 | /* Just so garbage doesn't ever shine through. */ |
| 1473 | memset (buffer, 0, this_size); |
| 1474 | |
| 1475 | if (optim) |
| 1476 | set_value_optimized_out (v, 1); |
| 1477 | if (unavail) |
| 1478 | mark_value_bytes_unavailable (v, offset, this_size); |
| 1479 | } |
| 1480 | } |
| 1481 | else |
| 1482 | { |
| 1483 | error (_("Unable to access DWARF register number %s"), |
| 1484 | paddress (arch, p->v.regno)); |
| 1485 | } |
| 1486 | } |
| 1487 | break; |
| 1488 | |
| 1489 | case DWARF_VALUE_MEMORY: |
| 1490 | read_value_memory (v, offset, |
| 1491 | p->v.mem.in_stack_memory, |
| 1492 | p->v.mem.addr + source_offset, |
| 1493 | buffer, this_size); |
| 1494 | break; |
| 1495 | |
| 1496 | case DWARF_VALUE_STACK: |
| 1497 | { |
| 1498 | size_t n = this_size; |
| 1499 | |
| 1500 | if (n > c->addr_size - source_offset) |
| 1501 | n = (c->addr_size >= source_offset |
| 1502 | ? c->addr_size - source_offset |
| 1503 | : 0); |
| 1504 | if (n == 0) |
| 1505 | { |
| 1506 | /* Nothing. */ |
| 1507 | } |
| 1508 | else |
| 1509 | { |
| 1510 | const gdb_byte *val_bytes = value_contents_all (p->v.value); |
| 1511 | |
| 1512 | intermediate_buffer = val_bytes + source_offset; |
| 1513 | } |
| 1514 | } |
| 1515 | break; |
| 1516 | |
| 1517 | case DWARF_VALUE_LITERAL: |
| 1518 | { |
| 1519 | size_t n = this_size; |
| 1520 | |
| 1521 | if (n > p->v.literal.length - source_offset) |
| 1522 | n = (p->v.literal.length >= source_offset |
| 1523 | ? p->v.literal.length - source_offset |
| 1524 | : 0); |
| 1525 | if (n != 0) |
| 1526 | intermediate_buffer = p->v.literal.data + source_offset; |
| 1527 | } |
| 1528 | break; |
| 1529 | |
| 1530 | /* These bits show up as zeros -- but do not cause the value |
| 1531 | to be considered optimized-out. */ |
| 1532 | case DWARF_VALUE_IMPLICIT_POINTER: |
| 1533 | break; |
| 1534 | |
| 1535 | case DWARF_VALUE_OPTIMIZED_OUT: |
| 1536 | set_value_optimized_out (v, 1); |
| 1537 | break; |
| 1538 | |
| 1539 | default: |
| 1540 | internal_error (__FILE__, __LINE__, _("invalid location type")); |
| 1541 | } |
| 1542 | |
| 1543 | if (p->location != DWARF_VALUE_OPTIMIZED_OUT |
| 1544 | && p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| 1545 | copy_bitwise (contents, dest_offset_bits, |
| 1546 | intermediate_buffer, source_offset_bits % 8, |
| 1547 | this_size_bits, bits_big_endian); |
| 1548 | |
| 1549 | offset += this_size_bits; |
| 1550 | } |
| 1551 | |
| 1552 | do_cleanups (cleanup); |
| 1553 | } |
| 1554 | |
| 1555 | static void |
| 1556 | write_pieced_value (struct value *to, struct value *from) |
| 1557 | { |
| 1558 | int i; |
| 1559 | long offset = 0; |
| 1560 | ULONGEST bits_to_skip; |
| 1561 | const gdb_byte *contents; |
| 1562 | struct piece_closure *c |
| 1563 | = (struct piece_closure *) value_computed_closure (to); |
| 1564 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to)); |
| 1565 | size_t type_len; |
| 1566 | size_t buffer_size = 0; |
| 1567 | char *buffer = NULL; |
| 1568 | struct cleanup *cleanup; |
| 1569 | int bits_big_endian |
| 1570 | = gdbarch_bits_big_endian (get_type_arch (value_type (to))); |
| 1571 | |
| 1572 | if (frame == NULL) |
| 1573 | { |
| 1574 | set_value_optimized_out (to, 1); |
| 1575 | return; |
| 1576 | } |
| 1577 | |
| 1578 | cleanup = make_cleanup (free_current_contents, &buffer); |
| 1579 | |
| 1580 | contents = value_contents (from); |
| 1581 | bits_to_skip = 8 * value_offset (to); |
| 1582 | if (value_bitsize (to)) |
| 1583 | { |
| 1584 | bits_to_skip += value_bitpos (to); |
| 1585 | type_len = value_bitsize (to); |
| 1586 | } |
| 1587 | else |
| 1588 | type_len = 8 * TYPE_LENGTH (value_type (to)); |
| 1589 | |
| 1590 | for (i = 0; i < c->n_pieces && offset < type_len; i++) |
| 1591 | { |
| 1592 | struct dwarf_expr_piece *p = &c->pieces[i]; |
| 1593 | size_t this_size_bits, this_size; |
| 1594 | long dest_offset_bits, source_offset_bits, dest_offset, source_offset; |
| 1595 | int need_bitwise; |
| 1596 | const gdb_byte *source_buffer; |
| 1597 | |
| 1598 | this_size_bits = p->size; |
| 1599 | if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) |
| 1600 | { |
| 1601 | bits_to_skip -= this_size_bits; |
| 1602 | continue; |
| 1603 | } |
| 1604 | if (this_size_bits > type_len - offset) |
| 1605 | this_size_bits = type_len - offset; |
| 1606 | if (bits_to_skip > 0) |
| 1607 | { |
| 1608 | dest_offset_bits = bits_to_skip; |
| 1609 | source_offset_bits = 0; |
| 1610 | this_size_bits -= bits_to_skip; |
| 1611 | bits_to_skip = 0; |
| 1612 | } |
| 1613 | else |
| 1614 | { |
| 1615 | dest_offset_bits = 0; |
| 1616 | source_offset_bits = offset; |
| 1617 | } |
| 1618 | |
| 1619 | this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; |
| 1620 | source_offset = source_offset_bits / 8; |
| 1621 | dest_offset = dest_offset_bits / 8; |
| 1622 | if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0) |
| 1623 | { |
| 1624 | source_buffer = contents + source_offset; |
| 1625 | need_bitwise = 0; |
| 1626 | } |
| 1627 | else |
| 1628 | { |
| 1629 | if (buffer_size < this_size) |
| 1630 | { |
| 1631 | buffer_size = this_size; |
| 1632 | buffer = xrealloc (buffer, buffer_size); |
| 1633 | } |
| 1634 | source_buffer = buffer; |
| 1635 | need_bitwise = 1; |
| 1636 | } |
| 1637 | |
| 1638 | switch (p->location) |
| 1639 | { |
| 1640 | case DWARF_VALUE_REGISTER: |
| 1641 | { |
| 1642 | struct gdbarch *arch = get_frame_arch (frame); |
| 1643 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno); |
| 1644 | int reg_offset = dest_offset; |
| 1645 | |
| 1646 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG |
| 1647 | && this_size <= register_size (arch, gdb_regnum)) |
| 1648 | /* Big-endian, and we want less than full size. */ |
| 1649 | reg_offset = register_size (arch, gdb_regnum) - this_size; |
| 1650 | |
| 1651 | if (gdb_regnum != -1) |
| 1652 | { |
| 1653 | if (need_bitwise) |
| 1654 | { |
| 1655 | int optim, unavail; |
| 1656 | |
| 1657 | if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| 1658 | this_size, buffer, |
| 1659 | &optim, &unavail)) |
| 1660 | { |
| 1661 | if (optim) |
| 1662 | error (_("Can't do read-modify-write to " |
| 1663 | "update bitfield; containing word has been " |
| 1664 | "optimized out")); |
| 1665 | if (unavail) |
| 1666 | throw_error (NOT_AVAILABLE_ERROR, |
| 1667 | _("Can't do read-modify-write to update " |
| 1668 | "bitfield; containing word " |
| 1669 | "is unavailable")); |
| 1670 | } |
| 1671 | copy_bitwise (buffer, dest_offset_bits, |
| 1672 | contents, source_offset_bits, |
| 1673 | this_size_bits, |
| 1674 | bits_big_endian); |
| 1675 | } |
| 1676 | |
| 1677 | put_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| 1678 | this_size, source_buffer); |
| 1679 | } |
| 1680 | else |
| 1681 | { |
| 1682 | error (_("Unable to write to DWARF register number %s"), |
| 1683 | paddress (arch, p->v.regno)); |
| 1684 | } |
| 1685 | } |
| 1686 | break; |
| 1687 | case DWARF_VALUE_MEMORY: |
| 1688 | if (need_bitwise) |
| 1689 | { |
| 1690 | /* Only the first and last bytes can possibly have any |
| 1691 | bits reused. */ |
| 1692 | read_memory (p->v.mem.addr + dest_offset, buffer, 1); |
| 1693 | read_memory (p->v.mem.addr + dest_offset + this_size - 1, |
| 1694 | buffer + this_size - 1, 1); |
| 1695 | copy_bitwise (buffer, dest_offset_bits, |
| 1696 | contents, source_offset_bits, |
| 1697 | this_size_bits, |
| 1698 | bits_big_endian); |
| 1699 | } |
| 1700 | |
| 1701 | write_memory (p->v.mem.addr + dest_offset, |
| 1702 | source_buffer, this_size); |
| 1703 | break; |
| 1704 | default: |
| 1705 | set_value_optimized_out (to, 1); |
| 1706 | break; |
| 1707 | } |
| 1708 | offset += this_size_bits; |
| 1709 | } |
| 1710 | |
| 1711 | do_cleanups (cleanup); |
| 1712 | } |
| 1713 | |
| 1714 | /* A helper function that checks bit validity in a pieced value. |
| 1715 | CHECK_FOR indicates the kind of validity checking. |
| 1716 | DWARF_VALUE_MEMORY means to check whether any bit is valid. |
| 1717 | DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is |
| 1718 | optimized out. |
| 1719 | DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an |
| 1720 | implicit pointer. */ |
| 1721 | |
| 1722 | static int |
| 1723 | check_pieced_value_bits (const struct value *value, int bit_offset, |
| 1724 | int bit_length, |
| 1725 | enum dwarf_value_location check_for) |
| 1726 | { |
| 1727 | struct piece_closure *c |
| 1728 | = (struct piece_closure *) value_computed_closure (value); |
| 1729 | int i; |
| 1730 | int validity = (check_for == DWARF_VALUE_MEMORY |
| 1731 | || check_for == DWARF_VALUE_IMPLICIT_POINTER); |
| 1732 | |
| 1733 | bit_offset += 8 * value_offset (value); |
| 1734 | if (value_bitsize (value)) |
| 1735 | bit_offset += value_bitpos (value); |
| 1736 | |
| 1737 | for (i = 0; i < c->n_pieces && bit_length > 0; i++) |
| 1738 | { |
| 1739 | struct dwarf_expr_piece *p = &c->pieces[i]; |
| 1740 | size_t this_size_bits = p->size; |
| 1741 | |
| 1742 | if (bit_offset > 0) |
| 1743 | { |
| 1744 | if (bit_offset >= this_size_bits) |
| 1745 | { |
| 1746 | bit_offset -= this_size_bits; |
| 1747 | continue; |
| 1748 | } |
| 1749 | |
| 1750 | bit_length -= this_size_bits - bit_offset; |
| 1751 | bit_offset = 0; |
| 1752 | } |
| 1753 | else |
| 1754 | bit_length -= this_size_bits; |
| 1755 | |
| 1756 | if (check_for == DWARF_VALUE_IMPLICIT_POINTER) |
| 1757 | { |
| 1758 | if (p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| 1759 | return 0; |
| 1760 | } |
| 1761 | else if (p->location == DWARF_VALUE_OPTIMIZED_OUT |
| 1762 | || p->location == DWARF_VALUE_IMPLICIT_POINTER) |
| 1763 | { |
| 1764 | if (validity) |
| 1765 | return 0; |
| 1766 | } |
| 1767 | else |
| 1768 | { |
| 1769 | if (!validity) |
| 1770 | return 1; |
| 1771 | } |
| 1772 | } |
| 1773 | |
| 1774 | return validity; |
| 1775 | } |
| 1776 | |
| 1777 | static int |
| 1778 | check_pieced_value_validity (const struct value *value, int bit_offset, |
| 1779 | int bit_length) |
| 1780 | { |
| 1781 | return check_pieced_value_bits (value, bit_offset, bit_length, |
| 1782 | DWARF_VALUE_MEMORY); |
| 1783 | } |
| 1784 | |
| 1785 | static int |
| 1786 | check_pieced_value_invalid (const struct value *value) |
| 1787 | { |
| 1788 | return check_pieced_value_bits (value, 0, |
| 1789 | 8 * TYPE_LENGTH (value_type (value)), |
| 1790 | DWARF_VALUE_OPTIMIZED_OUT); |
| 1791 | } |
| 1792 | |
| 1793 | /* An implementation of an lval_funcs method to see whether a value is |
| 1794 | a synthetic pointer. */ |
| 1795 | |
| 1796 | static int |
| 1797 | check_pieced_synthetic_pointer (const struct value *value, int bit_offset, |
| 1798 | int bit_length) |
| 1799 | { |
| 1800 | return check_pieced_value_bits (value, bit_offset, bit_length, |
| 1801 | DWARF_VALUE_IMPLICIT_POINTER); |
| 1802 | } |
| 1803 | |
| 1804 | /* A wrapper function for get_frame_address_in_block. */ |
| 1805 | |
| 1806 | static CORE_ADDR |
| 1807 | get_frame_address_in_block_wrapper (void *baton) |
| 1808 | { |
| 1809 | return get_frame_address_in_block (baton); |
| 1810 | } |
| 1811 | |
| 1812 | /* An implementation of an lval_funcs method to indirect through a |
| 1813 | pointer. This handles the synthetic pointer case when needed. */ |
| 1814 | |
| 1815 | static struct value * |
| 1816 | indirect_pieced_value (struct value *value) |
| 1817 | { |
| 1818 | struct piece_closure *c |
| 1819 | = (struct piece_closure *) value_computed_closure (value); |
| 1820 | struct type *type; |
| 1821 | struct frame_info *frame; |
| 1822 | struct dwarf2_locexpr_baton baton; |
| 1823 | int i, bit_offset, bit_length; |
| 1824 | struct dwarf_expr_piece *piece = NULL; |
| 1825 | LONGEST byte_offset; |
| 1826 | |
| 1827 | type = check_typedef (value_type (value)); |
| 1828 | if (TYPE_CODE (type) != TYPE_CODE_PTR) |
| 1829 | return NULL; |
| 1830 | |
| 1831 | bit_length = 8 * TYPE_LENGTH (type); |
| 1832 | bit_offset = 8 * value_offset (value); |
| 1833 | if (value_bitsize (value)) |
| 1834 | bit_offset += value_bitpos (value); |
| 1835 | |
| 1836 | for (i = 0; i < c->n_pieces && bit_length > 0; i++) |
| 1837 | { |
| 1838 | struct dwarf_expr_piece *p = &c->pieces[i]; |
| 1839 | size_t this_size_bits = p->size; |
| 1840 | |
| 1841 | if (bit_offset > 0) |
| 1842 | { |
| 1843 | if (bit_offset >= this_size_bits) |
| 1844 | { |
| 1845 | bit_offset -= this_size_bits; |
| 1846 | continue; |
| 1847 | } |
| 1848 | |
| 1849 | bit_length -= this_size_bits - bit_offset; |
| 1850 | bit_offset = 0; |
| 1851 | } |
| 1852 | else |
| 1853 | bit_length -= this_size_bits; |
| 1854 | |
| 1855 | if (p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| 1856 | return NULL; |
| 1857 | |
| 1858 | if (bit_length != 0) |
| 1859 | error (_("Invalid use of DW_OP_GNU_implicit_pointer")); |
| 1860 | |
| 1861 | piece = p; |
| 1862 | break; |
| 1863 | } |
| 1864 | |
| 1865 | frame = get_selected_frame (_("No frame selected.")); |
| 1866 | |
| 1867 | /* This is an offset requested by GDB, such as value subcripts. */ |
| 1868 | byte_offset = value_as_address (value); |
| 1869 | |
| 1870 | gdb_assert (piece); |
| 1871 | baton = dwarf2_fetch_die_location_block (piece->v.ptr.die, c->per_cu, |
| 1872 | get_frame_address_in_block_wrapper, |
| 1873 | frame); |
| 1874 | |
| 1875 | return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame, |
| 1876 | baton.data, baton.size, baton.per_cu, |
| 1877 | piece->v.ptr.offset + byte_offset); |
| 1878 | } |
| 1879 | |
| 1880 | static void * |
| 1881 | copy_pieced_value_closure (const struct value *v) |
| 1882 | { |
| 1883 | struct piece_closure *c |
| 1884 | = (struct piece_closure *) value_computed_closure (v); |
| 1885 | |
| 1886 | ++c->refc; |
| 1887 | return c; |
| 1888 | } |
| 1889 | |
| 1890 | static void |
| 1891 | free_pieced_value_closure (struct value *v) |
| 1892 | { |
| 1893 | struct piece_closure *c |
| 1894 | = (struct piece_closure *) value_computed_closure (v); |
| 1895 | |
| 1896 | --c->refc; |
| 1897 | if (c->refc == 0) |
| 1898 | { |
| 1899 | int i; |
| 1900 | |
| 1901 | for (i = 0; i < c->n_pieces; ++i) |
| 1902 | if (c->pieces[i].location == DWARF_VALUE_STACK) |
| 1903 | value_free (c->pieces[i].v.value); |
| 1904 | |
| 1905 | xfree (c->pieces); |
| 1906 | xfree (c); |
| 1907 | } |
| 1908 | } |
| 1909 | |
| 1910 | /* Functions for accessing a variable described by DW_OP_piece. */ |
| 1911 | static const struct lval_funcs pieced_value_funcs = { |
| 1912 | read_pieced_value, |
| 1913 | write_pieced_value, |
| 1914 | check_pieced_value_validity, |
| 1915 | check_pieced_value_invalid, |
| 1916 | indirect_pieced_value, |
| 1917 | NULL, /* coerce_ref */ |
| 1918 | check_pieced_synthetic_pointer, |
| 1919 | copy_pieced_value_closure, |
| 1920 | free_pieced_value_closure |
| 1921 | }; |
| 1922 | |
| 1923 | /* Helper function which throws an error if a synthetic pointer is |
| 1924 | invalid. */ |
| 1925 | |
| 1926 | static void |
| 1927 | invalid_synthetic_pointer (void) |
| 1928 | { |
| 1929 | error (_("access outside bounds of object " |
| 1930 | "referenced via synthetic pointer")); |
| 1931 | } |
| 1932 | |
| 1933 | /* Virtual method table for dwarf2_evaluate_loc_desc_full below. */ |
| 1934 | |
| 1935 | static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs = |
| 1936 | { |
| 1937 | dwarf_expr_read_reg, |
| 1938 | dwarf_expr_read_mem, |
| 1939 | dwarf_expr_frame_base, |
| 1940 | dwarf_expr_frame_cfa, |
| 1941 | dwarf_expr_frame_pc, |
| 1942 | dwarf_expr_tls_address, |
| 1943 | dwarf_expr_dwarf_call, |
| 1944 | dwarf_expr_get_base_type, |
| 1945 | dwarf_expr_push_dwarf_reg_entry_value |
| 1946 | }; |
| 1947 | |
| 1948 | /* Evaluate a location description, starting at DATA and with length |
| 1949 | SIZE, to find the current location of variable of TYPE in the |
| 1950 | context of FRAME. BYTE_OFFSET is applied after the contents are |
| 1951 | computed. */ |
| 1952 | |
| 1953 | static struct value * |
| 1954 | dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, |
| 1955 | const gdb_byte *data, unsigned short size, |
| 1956 | struct dwarf2_per_cu_data *per_cu, |
| 1957 | LONGEST byte_offset) |
| 1958 | { |
| 1959 | struct value *retval; |
| 1960 | struct dwarf_expr_baton baton; |
| 1961 | struct dwarf_expr_context *ctx; |
| 1962 | struct cleanup *old_chain, *value_chain; |
| 1963 | struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); |
| 1964 | volatile struct gdb_exception ex; |
| 1965 | |
| 1966 | if (byte_offset < 0) |
| 1967 | invalid_synthetic_pointer (); |
| 1968 | |
| 1969 | if (size == 0) |
| 1970 | return allocate_optimized_out_value (type); |
| 1971 | |
| 1972 | baton.frame = frame; |
| 1973 | baton.per_cu = per_cu; |
| 1974 | |
| 1975 | ctx = new_dwarf_expr_context (); |
| 1976 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
| 1977 | value_chain = make_cleanup_value_free_to_mark (value_mark ()); |
| 1978 | |
| 1979 | ctx->gdbarch = get_objfile_arch (objfile); |
| 1980 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
| 1981 | ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); |
| 1982 | ctx->offset = dwarf2_per_cu_text_offset (per_cu); |
| 1983 | ctx->baton = &baton; |
| 1984 | ctx->funcs = &dwarf_expr_ctx_funcs; |
| 1985 | |
| 1986 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
| 1987 | { |
| 1988 | dwarf_expr_eval (ctx, data, size); |
| 1989 | } |
| 1990 | if (ex.reason < 0) |
| 1991 | { |
| 1992 | if (ex.error == NOT_AVAILABLE_ERROR) |
| 1993 | { |
| 1994 | do_cleanups (old_chain); |
| 1995 | retval = allocate_value (type); |
| 1996 | mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type)); |
| 1997 | return retval; |
| 1998 | } |
| 1999 | else if (ex.error == NO_ENTRY_VALUE_ERROR) |
| 2000 | { |
| 2001 | if (entry_values_debug) |
| 2002 | exception_print (gdb_stdout, ex); |
| 2003 | do_cleanups (old_chain); |
| 2004 | return allocate_optimized_out_value (type); |
| 2005 | } |
| 2006 | else |
| 2007 | throw_exception (ex); |
| 2008 | } |
| 2009 | |
| 2010 | if (ctx->num_pieces > 0) |
| 2011 | { |
| 2012 | struct piece_closure *c; |
| 2013 | struct frame_id frame_id = get_frame_id (frame); |
| 2014 | ULONGEST bit_size = 0; |
| 2015 | int i; |
| 2016 | |
| 2017 | for (i = 0; i < ctx->num_pieces; ++i) |
| 2018 | bit_size += ctx->pieces[i].size; |
| 2019 | if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size) |
| 2020 | invalid_synthetic_pointer (); |
| 2021 | |
| 2022 | c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces, |
| 2023 | ctx->addr_size); |
| 2024 | /* We must clean up the value chain after creating the piece |
| 2025 | closure but before allocating the result. */ |
| 2026 | do_cleanups (value_chain); |
| 2027 | retval = allocate_computed_value (type, &pieced_value_funcs, c); |
| 2028 | VALUE_FRAME_ID (retval) = frame_id; |
| 2029 | set_value_offset (retval, byte_offset); |
| 2030 | } |
| 2031 | else |
| 2032 | { |
| 2033 | switch (ctx->location) |
| 2034 | { |
| 2035 | case DWARF_VALUE_REGISTER: |
| 2036 | { |
| 2037 | struct gdbarch *arch = get_frame_arch (frame); |
| 2038 | ULONGEST dwarf_regnum = value_as_long (dwarf_expr_fetch (ctx, 0)); |
| 2039 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum); |
| 2040 | |
| 2041 | if (byte_offset != 0) |
| 2042 | error (_("cannot use offset on synthetic pointer to register")); |
| 2043 | do_cleanups (value_chain); |
| 2044 | if (gdb_regnum != -1) |
| 2045 | retval = value_from_register (type, gdb_regnum, frame); |
| 2046 | else |
| 2047 | error (_("Unable to access DWARF register number %s"), |
| 2048 | paddress (arch, dwarf_regnum)); |
| 2049 | } |
| 2050 | break; |
| 2051 | |
| 2052 | case DWARF_VALUE_MEMORY: |
| 2053 | { |
| 2054 | CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0); |
| 2055 | int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); |
| 2056 | |
| 2057 | do_cleanups (value_chain); |
| 2058 | retval = allocate_value_lazy (type); |
| 2059 | VALUE_LVAL (retval) = lval_memory; |
| 2060 | if (in_stack_memory) |
| 2061 | set_value_stack (retval, 1); |
| 2062 | set_value_address (retval, address + byte_offset); |
| 2063 | } |
| 2064 | break; |
| 2065 | |
| 2066 | case DWARF_VALUE_STACK: |
| 2067 | { |
| 2068 | struct value *value = dwarf_expr_fetch (ctx, 0); |
| 2069 | gdb_byte *contents; |
| 2070 | const gdb_byte *val_bytes; |
| 2071 | size_t n = TYPE_LENGTH (value_type (value)); |
| 2072 | |
| 2073 | if (byte_offset + TYPE_LENGTH (type) > n) |
| 2074 | invalid_synthetic_pointer (); |
| 2075 | |
| 2076 | val_bytes = value_contents_all (value); |
| 2077 | val_bytes += byte_offset; |
| 2078 | n -= byte_offset; |
| 2079 | |
| 2080 | /* Preserve VALUE because we are going to free values back |
| 2081 | to the mark, but we still need the value contents |
| 2082 | below. */ |
| 2083 | value_incref (value); |
| 2084 | do_cleanups (value_chain); |
| 2085 | make_cleanup_value_free (value); |
| 2086 | |
| 2087 | retval = allocate_value (type); |
| 2088 | contents = value_contents_raw (retval); |
| 2089 | if (n > TYPE_LENGTH (type)) |
| 2090 | { |
| 2091 | struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile); |
| 2092 | |
| 2093 | if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG) |
| 2094 | val_bytes += n - TYPE_LENGTH (type); |
| 2095 | n = TYPE_LENGTH (type); |
| 2096 | } |
| 2097 | memcpy (contents, val_bytes, n); |
| 2098 | } |
| 2099 | break; |
| 2100 | |
| 2101 | case DWARF_VALUE_LITERAL: |
| 2102 | { |
| 2103 | bfd_byte *contents; |
| 2104 | const bfd_byte *ldata; |
| 2105 | size_t n = ctx->len; |
| 2106 | |
| 2107 | if (byte_offset + TYPE_LENGTH (type) > n) |
| 2108 | invalid_synthetic_pointer (); |
| 2109 | |
| 2110 | do_cleanups (value_chain); |
| 2111 | retval = allocate_value (type); |
| 2112 | contents = value_contents_raw (retval); |
| 2113 | |
| 2114 | ldata = ctx->data + byte_offset; |
| 2115 | n -= byte_offset; |
| 2116 | |
| 2117 | if (n > TYPE_LENGTH (type)) |
| 2118 | { |
| 2119 | struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile); |
| 2120 | |
| 2121 | if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG) |
| 2122 | ldata += n - TYPE_LENGTH (type); |
| 2123 | n = TYPE_LENGTH (type); |
| 2124 | } |
| 2125 | memcpy (contents, ldata, n); |
| 2126 | } |
| 2127 | break; |
| 2128 | |
| 2129 | case DWARF_VALUE_OPTIMIZED_OUT: |
| 2130 | do_cleanups (value_chain); |
| 2131 | retval = allocate_optimized_out_value (type); |
| 2132 | break; |
| 2133 | |
| 2134 | /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced |
| 2135 | operation by execute_stack_op. */ |
| 2136 | case DWARF_VALUE_IMPLICIT_POINTER: |
| 2137 | /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context -- |
| 2138 | it can only be encountered when making a piece. */ |
| 2139 | default: |
| 2140 | internal_error (__FILE__, __LINE__, _("invalid location type")); |
| 2141 | } |
| 2142 | } |
| 2143 | |
| 2144 | set_value_initialized (retval, ctx->initialized); |
| 2145 | |
| 2146 | do_cleanups (old_chain); |
| 2147 | |
| 2148 | return retval; |
| 2149 | } |
| 2150 | |
| 2151 | /* The exported interface to dwarf2_evaluate_loc_desc_full; it always |
| 2152 | passes 0 as the byte_offset. */ |
| 2153 | |
| 2154 | struct value * |
| 2155 | dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, |
| 2156 | const gdb_byte *data, unsigned short size, |
| 2157 | struct dwarf2_per_cu_data *per_cu) |
| 2158 | { |
| 2159 | return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0); |
| 2160 | } |
| 2161 | |
| 2162 | \f |
| 2163 | /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */ |
| 2164 | |
| 2165 | struct needs_frame_baton |
| 2166 | { |
| 2167 | int needs_frame; |
| 2168 | struct dwarf2_per_cu_data *per_cu; |
| 2169 | }; |
| 2170 | |
| 2171 | /* Reads from registers do require a frame. */ |
| 2172 | static CORE_ADDR |
| 2173 | needs_frame_read_reg (void *baton, int regnum) |
| 2174 | { |
| 2175 | struct needs_frame_baton *nf_baton = baton; |
| 2176 | |
| 2177 | nf_baton->needs_frame = 1; |
| 2178 | return 1; |
| 2179 | } |
| 2180 | |
| 2181 | /* Reads from memory do not require a frame. */ |
| 2182 | static void |
| 2183 | needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
| 2184 | { |
| 2185 | memset (buf, 0, len); |
| 2186 | } |
| 2187 | |
| 2188 | /* Frame-relative accesses do require a frame. */ |
| 2189 | static void |
| 2190 | needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length) |
| 2191 | { |
| 2192 | static gdb_byte lit0 = DW_OP_lit0; |
| 2193 | struct needs_frame_baton *nf_baton = baton; |
| 2194 | |
| 2195 | *start = &lit0; |
| 2196 | *length = 1; |
| 2197 | |
| 2198 | nf_baton->needs_frame = 1; |
| 2199 | } |
| 2200 | |
| 2201 | /* CFA accesses require a frame. */ |
| 2202 | |
| 2203 | static CORE_ADDR |
| 2204 | needs_frame_frame_cfa (void *baton) |
| 2205 | { |
| 2206 | struct needs_frame_baton *nf_baton = baton; |
| 2207 | |
| 2208 | nf_baton->needs_frame = 1; |
| 2209 | return 1; |
| 2210 | } |
| 2211 | |
| 2212 | /* Thread-local accesses do require a frame. */ |
| 2213 | static CORE_ADDR |
| 2214 | needs_frame_tls_address (void *baton, CORE_ADDR offset) |
| 2215 | { |
| 2216 | struct needs_frame_baton *nf_baton = baton; |
| 2217 | |
| 2218 | nf_baton->needs_frame = 1; |
| 2219 | return 1; |
| 2220 | } |
| 2221 | |
| 2222 | /* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */ |
| 2223 | |
| 2224 | static void |
| 2225 | needs_frame_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset) |
| 2226 | { |
| 2227 | struct needs_frame_baton *nf_baton = ctx->baton; |
| 2228 | |
| 2229 | per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu, |
| 2230 | ctx->funcs->get_frame_pc, ctx->baton); |
| 2231 | } |
| 2232 | |
| 2233 | /* DW_OP_GNU_entry_value accesses require a caller, therefore a frame. */ |
| 2234 | |
| 2235 | static void |
| 2236 | needs_dwarf_reg_entry_value (struct dwarf_expr_context *ctx, |
| 2237 | int dwarf_reg, CORE_ADDR fb_offset, int deref_size) |
| 2238 | { |
| 2239 | struct needs_frame_baton *nf_baton = ctx->baton; |
| 2240 | |
| 2241 | nf_baton->needs_frame = 1; |
| 2242 | } |
| 2243 | |
| 2244 | /* Virtual method table for dwarf2_loc_desc_needs_frame below. */ |
| 2245 | |
| 2246 | static const struct dwarf_expr_context_funcs needs_frame_ctx_funcs = |
| 2247 | { |
| 2248 | needs_frame_read_reg, |
| 2249 | needs_frame_read_mem, |
| 2250 | needs_frame_frame_base, |
| 2251 | needs_frame_frame_cfa, |
| 2252 | needs_frame_frame_cfa, /* get_frame_pc */ |
| 2253 | needs_frame_tls_address, |
| 2254 | needs_frame_dwarf_call, |
| 2255 | NULL, /* get_base_type */ |
| 2256 | needs_dwarf_reg_entry_value |
| 2257 | }; |
| 2258 | |
| 2259 | /* Return non-zero iff the location expression at DATA (length SIZE) |
| 2260 | requires a frame to evaluate. */ |
| 2261 | |
| 2262 | static int |
| 2263 | dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, |
| 2264 | struct dwarf2_per_cu_data *per_cu) |
| 2265 | { |
| 2266 | struct needs_frame_baton baton; |
| 2267 | struct dwarf_expr_context *ctx; |
| 2268 | int in_reg; |
| 2269 | struct cleanup *old_chain; |
| 2270 | struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); |
| 2271 | |
| 2272 | baton.needs_frame = 0; |
| 2273 | baton.per_cu = per_cu; |
| 2274 | |
| 2275 | ctx = new_dwarf_expr_context (); |
| 2276 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
| 2277 | make_cleanup_value_free_to_mark (value_mark ()); |
| 2278 | |
| 2279 | ctx->gdbarch = get_objfile_arch (objfile); |
| 2280 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
| 2281 | ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); |
| 2282 | ctx->offset = dwarf2_per_cu_text_offset (per_cu); |
| 2283 | ctx->baton = &baton; |
| 2284 | ctx->funcs = &needs_frame_ctx_funcs; |
| 2285 | |
| 2286 | dwarf_expr_eval (ctx, data, size); |
| 2287 | |
| 2288 | in_reg = ctx->location == DWARF_VALUE_REGISTER; |
| 2289 | |
| 2290 | if (ctx->num_pieces > 0) |
| 2291 | { |
| 2292 | int i; |
| 2293 | |
| 2294 | /* If the location has several pieces, and any of them are in |
| 2295 | registers, then we will need a frame to fetch them from. */ |
| 2296 | for (i = 0; i < ctx->num_pieces; i++) |
| 2297 | if (ctx->pieces[i].location == DWARF_VALUE_REGISTER) |
| 2298 | in_reg = 1; |
| 2299 | } |
| 2300 | |
| 2301 | do_cleanups (old_chain); |
| 2302 | |
| 2303 | return baton.needs_frame || in_reg; |
| 2304 | } |
| 2305 | |
| 2306 | /* A helper function that throws an unimplemented error mentioning a |
| 2307 | given DWARF operator. */ |
| 2308 | |
| 2309 | static void |
| 2310 | unimplemented (unsigned int op) |
| 2311 | { |
| 2312 | const char *name = dwarf_stack_op_name (op); |
| 2313 | |
| 2314 | if (name) |
| 2315 | error (_("DWARF operator %s cannot be translated to an agent expression"), |
| 2316 | name); |
| 2317 | else |
| 2318 | error (_("Unknown DWARF operator 0x%02x cannot be translated " |
| 2319 | "to an agent expression"), |
| 2320 | op); |
| 2321 | } |
| 2322 | |
| 2323 | /* A helper function to convert a DWARF register to an arch register. |
| 2324 | ARCH is the architecture. |
| 2325 | DWARF_REG is the register. |
| 2326 | This will throw an exception if the DWARF register cannot be |
| 2327 | translated to an architecture register. */ |
| 2328 | |
| 2329 | static int |
| 2330 | translate_register (struct gdbarch *arch, int dwarf_reg) |
| 2331 | { |
| 2332 | int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg); |
| 2333 | if (reg == -1) |
| 2334 | error (_("Unable to access DWARF register number %d"), dwarf_reg); |
| 2335 | return reg; |
| 2336 | } |
| 2337 | |
| 2338 | /* A helper function that emits an access to memory. ARCH is the |
| 2339 | target architecture. EXPR is the expression which we are building. |
| 2340 | NBITS is the number of bits we want to read. This emits the |
| 2341 | opcodes needed to read the memory and then extract the desired |
| 2342 | bits. */ |
| 2343 | |
| 2344 | static void |
| 2345 | access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits) |
| 2346 | { |
| 2347 | ULONGEST nbytes = (nbits + 7) / 8; |
| 2348 | |
| 2349 | gdb_assert (nbits > 0 && nbits <= sizeof (LONGEST)); |
| 2350 | |
| 2351 | if (trace_kludge) |
| 2352 | ax_trace_quick (expr, nbytes); |
| 2353 | |
| 2354 | if (nbits <= 8) |
| 2355 | ax_simple (expr, aop_ref8); |
| 2356 | else if (nbits <= 16) |
| 2357 | ax_simple (expr, aop_ref16); |
| 2358 | else if (nbits <= 32) |
| 2359 | ax_simple (expr, aop_ref32); |
| 2360 | else |
| 2361 | ax_simple (expr, aop_ref64); |
| 2362 | |
| 2363 | /* If we read exactly the number of bytes we wanted, we're done. */ |
| 2364 | if (8 * nbytes == nbits) |
| 2365 | return; |
| 2366 | |
| 2367 | if (gdbarch_bits_big_endian (arch)) |
| 2368 | { |
| 2369 | /* On a bits-big-endian machine, we want the high-order |
| 2370 | NBITS. */ |
| 2371 | ax_const_l (expr, 8 * nbytes - nbits); |
| 2372 | ax_simple (expr, aop_rsh_unsigned); |
| 2373 | } |
| 2374 | else |
| 2375 | { |
| 2376 | /* On a bits-little-endian box, we want the low-order NBITS. */ |
| 2377 | ax_zero_ext (expr, nbits); |
| 2378 | } |
| 2379 | } |
| 2380 | |
| 2381 | /* A helper function to return the frame's PC. */ |
| 2382 | |
| 2383 | static CORE_ADDR |
| 2384 | get_ax_pc (void *baton) |
| 2385 | { |
| 2386 | struct agent_expr *expr = baton; |
| 2387 | |
| 2388 | return expr->scope; |
| 2389 | } |
| 2390 | |
| 2391 | /* Compile a DWARF location expression to an agent expression. |
| 2392 | |
| 2393 | EXPR is the agent expression we are building. |
| 2394 | LOC is the agent value we modify. |
| 2395 | ARCH is the architecture. |
| 2396 | ADDR_SIZE is the size of addresses, in bytes. |
| 2397 | OP_PTR is the start of the location expression. |
| 2398 | OP_END is one past the last byte of the location expression. |
| 2399 | |
| 2400 | This will throw an exception for various kinds of errors -- for |
| 2401 | example, if the expression cannot be compiled, or if the expression |
| 2402 | is invalid. */ |
| 2403 | |
| 2404 | void |
| 2405 | dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, |
| 2406 | struct gdbarch *arch, unsigned int addr_size, |
| 2407 | const gdb_byte *op_ptr, const gdb_byte *op_end, |
| 2408 | struct dwarf2_per_cu_data *per_cu) |
| 2409 | { |
| 2410 | struct cleanup *cleanups; |
| 2411 | int i, *offsets; |
| 2412 | VEC(int) *dw_labels = NULL, *patches = NULL; |
| 2413 | const gdb_byte * const base = op_ptr; |
| 2414 | const gdb_byte *previous_piece = op_ptr; |
| 2415 | enum bfd_endian byte_order = gdbarch_byte_order (arch); |
| 2416 | ULONGEST bits_collected = 0; |
| 2417 | unsigned int addr_size_bits = 8 * addr_size; |
| 2418 | int bits_big_endian = gdbarch_bits_big_endian (arch); |
| 2419 | |
| 2420 | offsets = xmalloc ((op_end - op_ptr) * sizeof (int)); |
| 2421 | cleanups = make_cleanup (xfree, offsets); |
| 2422 | |
| 2423 | for (i = 0; i < op_end - op_ptr; ++i) |
| 2424 | offsets[i] = -1; |
| 2425 | |
| 2426 | make_cleanup (VEC_cleanup (int), &dw_labels); |
| 2427 | make_cleanup (VEC_cleanup (int), &patches); |
| 2428 | |
| 2429 | /* By default we are making an address. */ |
| 2430 | loc->kind = axs_lvalue_memory; |
| 2431 | |
| 2432 | while (op_ptr < op_end) |
| 2433 | { |
| 2434 | enum dwarf_location_atom op = *op_ptr; |
| 2435 | ULONGEST uoffset, reg; |
| 2436 | LONGEST offset; |
| 2437 | int i; |
| 2438 | |
| 2439 | offsets[op_ptr - base] = expr->len; |
| 2440 | ++op_ptr; |
| 2441 | |
| 2442 | /* Our basic approach to code generation is to map DWARF |
| 2443 | operations directly to AX operations. However, there are |
| 2444 | some differences. |
| 2445 | |
| 2446 | First, DWARF works on address-sized units, but AX always uses |
| 2447 | LONGEST. For most operations we simply ignore this |
| 2448 | difference; instead we generate sign extensions as needed |
| 2449 | before division and comparison operations. It would be nice |
| 2450 | to omit the sign extensions, but there is no way to determine |
| 2451 | the size of the target's LONGEST. (This code uses the size |
| 2452 | of the host LONGEST in some cases -- that is a bug but it is |
| 2453 | difficult to fix.) |
| 2454 | |
| 2455 | Second, some DWARF operations cannot be translated to AX. |
| 2456 | For these we simply fail. See |
| 2457 | http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */ |
| 2458 | switch (op) |
| 2459 | { |
| 2460 | case DW_OP_lit0: |
| 2461 | case DW_OP_lit1: |
| 2462 | case DW_OP_lit2: |
| 2463 | case DW_OP_lit3: |
| 2464 | case DW_OP_lit4: |
| 2465 | case DW_OP_lit5: |
| 2466 | case DW_OP_lit6: |
| 2467 | case DW_OP_lit7: |
| 2468 | case DW_OP_lit8: |
| 2469 | case DW_OP_lit9: |
| 2470 | case DW_OP_lit10: |
| 2471 | case DW_OP_lit11: |
| 2472 | case DW_OP_lit12: |
| 2473 | case DW_OP_lit13: |
| 2474 | case DW_OP_lit14: |
| 2475 | case DW_OP_lit15: |
| 2476 | case DW_OP_lit16: |
| 2477 | case DW_OP_lit17: |
| 2478 | case DW_OP_lit18: |
| 2479 | case DW_OP_lit19: |
| 2480 | case DW_OP_lit20: |
| 2481 | case DW_OP_lit21: |
| 2482 | case DW_OP_lit22: |
| 2483 | case DW_OP_lit23: |
| 2484 | case DW_OP_lit24: |
| 2485 | case DW_OP_lit25: |
| 2486 | case DW_OP_lit26: |
| 2487 | case DW_OP_lit27: |
| 2488 | case DW_OP_lit28: |
| 2489 | case DW_OP_lit29: |
| 2490 | case DW_OP_lit30: |
| 2491 | case DW_OP_lit31: |
| 2492 | ax_const_l (expr, op - DW_OP_lit0); |
| 2493 | break; |
| 2494 | |
| 2495 | case DW_OP_addr: |
| 2496 | uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order); |
| 2497 | op_ptr += addr_size; |
| 2498 | /* Some versions of GCC emit DW_OP_addr before |
| 2499 | DW_OP_GNU_push_tls_address. In this case the value is an |
| 2500 | index, not an address. We don't support things like |
| 2501 | branching between the address and the TLS op. */ |
| 2502 | if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address) |
| 2503 | uoffset += dwarf2_per_cu_text_offset (per_cu); |
| 2504 | ax_const_l (expr, uoffset); |
| 2505 | break; |
| 2506 | |
| 2507 | case DW_OP_const1u: |
| 2508 | ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order)); |
| 2509 | op_ptr += 1; |
| 2510 | break; |
| 2511 | case DW_OP_const1s: |
| 2512 | ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order)); |
| 2513 | op_ptr += 1; |
| 2514 | break; |
| 2515 | case DW_OP_const2u: |
| 2516 | ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order)); |
| 2517 | op_ptr += 2; |
| 2518 | break; |
| 2519 | case DW_OP_const2s: |
| 2520 | ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order)); |
| 2521 | op_ptr += 2; |
| 2522 | break; |
| 2523 | case DW_OP_const4u: |
| 2524 | ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order)); |
| 2525 | op_ptr += 4; |
| 2526 | break; |
| 2527 | case DW_OP_const4s: |
| 2528 | ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order)); |
| 2529 | op_ptr += 4; |
| 2530 | break; |
| 2531 | case DW_OP_const8u: |
| 2532 | ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order)); |
| 2533 | op_ptr += 8; |
| 2534 | break; |
| 2535 | case DW_OP_const8s: |
| 2536 | ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order)); |
| 2537 | op_ptr += 8; |
| 2538 | break; |
| 2539 | case DW_OP_constu: |
| 2540 | op_ptr = read_uleb128 (op_ptr, op_end, &uoffset); |
| 2541 | ax_const_l (expr, uoffset); |
| 2542 | break; |
| 2543 | case DW_OP_consts: |
| 2544 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 2545 | ax_const_l (expr, offset); |
| 2546 | break; |
| 2547 | |
| 2548 | case DW_OP_reg0: |
| 2549 | case DW_OP_reg1: |
| 2550 | case DW_OP_reg2: |
| 2551 | case DW_OP_reg3: |
| 2552 | case DW_OP_reg4: |
| 2553 | case DW_OP_reg5: |
| 2554 | case DW_OP_reg6: |
| 2555 | case DW_OP_reg7: |
| 2556 | case DW_OP_reg8: |
| 2557 | case DW_OP_reg9: |
| 2558 | case DW_OP_reg10: |
| 2559 | case DW_OP_reg11: |
| 2560 | case DW_OP_reg12: |
| 2561 | case DW_OP_reg13: |
| 2562 | case DW_OP_reg14: |
| 2563 | case DW_OP_reg15: |
| 2564 | case DW_OP_reg16: |
| 2565 | case DW_OP_reg17: |
| 2566 | case DW_OP_reg18: |
| 2567 | case DW_OP_reg19: |
| 2568 | case DW_OP_reg20: |
| 2569 | case DW_OP_reg21: |
| 2570 | case DW_OP_reg22: |
| 2571 | case DW_OP_reg23: |
| 2572 | case DW_OP_reg24: |
| 2573 | case DW_OP_reg25: |
| 2574 | case DW_OP_reg26: |
| 2575 | case DW_OP_reg27: |
| 2576 | case DW_OP_reg28: |
| 2577 | case DW_OP_reg29: |
| 2578 | case DW_OP_reg30: |
| 2579 | case DW_OP_reg31: |
| 2580 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| 2581 | loc->u.reg = translate_register (arch, op - DW_OP_reg0); |
| 2582 | loc->kind = axs_lvalue_register; |
| 2583 | break; |
| 2584 | |
| 2585 | case DW_OP_regx: |
| 2586 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 2587 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| 2588 | loc->u.reg = translate_register (arch, reg); |
| 2589 | loc->kind = axs_lvalue_register; |
| 2590 | break; |
| 2591 | |
| 2592 | case DW_OP_implicit_value: |
| 2593 | { |
| 2594 | ULONGEST len; |
| 2595 | |
| 2596 | op_ptr = read_uleb128 (op_ptr, op_end, &len); |
| 2597 | if (op_ptr + len > op_end) |
| 2598 | error (_("DW_OP_implicit_value: too few bytes available.")); |
| 2599 | if (len > sizeof (ULONGEST)) |
| 2600 | error (_("Cannot translate DW_OP_implicit_value of %d bytes"), |
| 2601 | (int) len); |
| 2602 | |
| 2603 | ax_const_l (expr, extract_unsigned_integer (op_ptr, len, |
| 2604 | byte_order)); |
| 2605 | op_ptr += len; |
| 2606 | dwarf_expr_require_composition (op_ptr, op_end, |
| 2607 | "DW_OP_implicit_value"); |
| 2608 | |
| 2609 | loc->kind = axs_rvalue; |
| 2610 | } |
| 2611 | break; |
| 2612 | |
| 2613 | case DW_OP_stack_value: |
| 2614 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value"); |
| 2615 | loc->kind = axs_rvalue; |
| 2616 | break; |
| 2617 | |
| 2618 | case DW_OP_breg0: |
| 2619 | case DW_OP_breg1: |
| 2620 | case DW_OP_breg2: |
| 2621 | case DW_OP_breg3: |
| 2622 | case DW_OP_breg4: |
| 2623 | case DW_OP_breg5: |
| 2624 | case DW_OP_breg6: |
| 2625 | case DW_OP_breg7: |
| 2626 | case DW_OP_breg8: |
| 2627 | case DW_OP_breg9: |
| 2628 | case DW_OP_breg10: |
| 2629 | case DW_OP_breg11: |
| 2630 | case DW_OP_breg12: |
| 2631 | case DW_OP_breg13: |
| 2632 | case DW_OP_breg14: |
| 2633 | case DW_OP_breg15: |
| 2634 | case DW_OP_breg16: |
| 2635 | case DW_OP_breg17: |
| 2636 | case DW_OP_breg18: |
| 2637 | case DW_OP_breg19: |
| 2638 | case DW_OP_breg20: |
| 2639 | case DW_OP_breg21: |
| 2640 | case DW_OP_breg22: |
| 2641 | case DW_OP_breg23: |
| 2642 | case DW_OP_breg24: |
| 2643 | case DW_OP_breg25: |
| 2644 | case DW_OP_breg26: |
| 2645 | case DW_OP_breg27: |
| 2646 | case DW_OP_breg28: |
| 2647 | case DW_OP_breg29: |
| 2648 | case DW_OP_breg30: |
| 2649 | case DW_OP_breg31: |
| 2650 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 2651 | i = translate_register (arch, op - DW_OP_breg0); |
| 2652 | ax_reg (expr, i); |
| 2653 | if (offset != 0) |
| 2654 | { |
| 2655 | ax_const_l (expr, offset); |
| 2656 | ax_simple (expr, aop_add); |
| 2657 | } |
| 2658 | break; |
| 2659 | case DW_OP_bregx: |
| 2660 | { |
| 2661 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 2662 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 2663 | i = translate_register (arch, reg); |
| 2664 | ax_reg (expr, i); |
| 2665 | if (offset != 0) |
| 2666 | { |
| 2667 | ax_const_l (expr, offset); |
| 2668 | ax_simple (expr, aop_add); |
| 2669 | } |
| 2670 | } |
| 2671 | break; |
| 2672 | case DW_OP_fbreg: |
| 2673 | { |
| 2674 | const gdb_byte *datastart; |
| 2675 | size_t datalen; |
| 2676 | unsigned int before_stack_len; |
| 2677 | struct block *b; |
| 2678 | struct symbol *framefunc; |
| 2679 | LONGEST base_offset = 0; |
| 2680 | |
| 2681 | b = block_for_pc (expr->scope); |
| 2682 | |
| 2683 | if (!b) |
| 2684 | error (_("No block found for address")); |
| 2685 | |
| 2686 | framefunc = block_linkage_function (b); |
| 2687 | |
| 2688 | if (!framefunc) |
| 2689 | error (_("No function found for block")); |
| 2690 | |
| 2691 | dwarf_expr_frame_base_1 (framefunc, expr->scope, |
| 2692 | &datastart, &datalen); |
| 2693 | |
| 2694 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 2695 | dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart, |
| 2696 | datastart + datalen, per_cu); |
| 2697 | |
| 2698 | if (offset != 0) |
| 2699 | { |
| 2700 | ax_const_l (expr, offset); |
| 2701 | ax_simple (expr, aop_add); |
| 2702 | } |
| 2703 | |
| 2704 | loc->kind = axs_lvalue_memory; |
| 2705 | } |
| 2706 | break; |
| 2707 | |
| 2708 | case DW_OP_dup: |
| 2709 | ax_simple (expr, aop_dup); |
| 2710 | break; |
| 2711 | |
| 2712 | case DW_OP_drop: |
| 2713 | ax_simple (expr, aop_pop); |
| 2714 | break; |
| 2715 | |
| 2716 | case DW_OP_pick: |
| 2717 | offset = *op_ptr++; |
| 2718 | ax_pick (expr, offset); |
| 2719 | break; |
| 2720 | |
| 2721 | case DW_OP_swap: |
| 2722 | ax_simple (expr, aop_swap); |
| 2723 | break; |
| 2724 | |
| 2725 | case DW_OP_over: |
| 2726 | ax_pick (expr, 1); |
| 2727 | break; |
| 2728 | |
| 2729 | case DW_OP_rot: |
| 2730 | ax_simple (expr, aop_rot); |
| 2731 | break; |
| 2732 | |
| 2733 | case DW_OP_deref: |
| 2734 | case DW_OP_deref_size: |
| 2735 | { |
| 2736 | int size; |
| 2737 | |
| 2738 | if (op == DW_OP_deref_size) |
| 2739 | size = *op_ptr++; |
| 2740 | else |
| 2741 | size = addr_size; |
| 2742 | |
| 2743 | switch (size) |
| 2744 | { |
| 2745 | case 8: |
| 2746 | ax_simple (expr, aop_ref8); |
| 2747 | break; |
| 2748 | case 16: |
| 2749 | ax_simple (expr, aop_ref16); |
| 2750 | break; |
| 2751 | case 32: |
| 2752 | ax_simple (expr, aop_ref32); |
| 2753 | break; |
| 2754 | case 64: |
| 2755 | ax_simple (expr, aop_ref64); |
| 2756 | break; |
| 2757 | default: |
| 2758 | /* Note that dwarf_stack_op_name will never return |
| 2759 | NULL here. */ |
| 2760 | error (_("Unsupported size %d in %s"), |
| 2761 | size, dwarf_stack_op_name (op)); |
| 2762 | } |
| 2763 | } |
| 2764 | break; |
| 2765 | |
| 2766 | case DW_OP_abs: |
| 2767 | /* Sign extend the operand. */ |
| 2768 | ax_ext (expr, addr_size_bits); |
| 2769 | ax_simple (expr, aop_dup); |
| 2770 | ax_const_l (expr, 0); |
| 2771 | ax_simple (expr, aop_less_signed); |
| 2772 | ax_simple (expr, aop_log_not); |
| 2773 | i = ax_goto (expr, aop_if_goto); |
| 2774 | /* We have to emit 0 - X. */ |
| 2775 | ax_const_l (expr, 0); |
| 2776 | ax_simple (expr, aop_swap); |
| 2777 | ax_simple (expr, aop_sub); |
| 2778 | ax_label (expr, i, expr->len); |
| 2779 | break; |
| 2780 | |
| 2781 | case DW_OP_neg: |
| 2782 | /* No need to sign extend here. */ |
| 2783 | ax_const_l (expr, 0); |
| 2784 | ax_simple (expr, aop_swap); |
| 2785 | ax_simple (expr, aop_sub); |
| 2786 | break; |
| 2787 | |
| 2788 | case DW_OP_not: |
| 2789 | /* Sign extend the operand. */ |
| 2790 | ax_ext (expr, addr_size_bits); |
| 2791 | ax_simple (expr, aop_bit_not); |
| 2792 | break; |
| 2793 | |
| 2794 | case DW_OP_plus_uconst: |
| 2795 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 2796 | /* It would be really weird to emit `DW_OP_plus_uconst 0', |
| 2797 | but we micro-optimize anyhow. */ |
| 2798 | if (reg != 0) |
| 2799 | { |
| 2800 | ax_const_l (expr, reg); |
| 2801 | ax_simple (expr, aop_add); |
| 2802 | } |
| 2803 | break; |
| 2804 | |
| 2805 | case DW_OP_and: |
| 2806 | ax_simple (expr, aop_bit_and); |
| 2807 | break; |
| 2808 | |
| 2809 | case DW_OP_div: |
| 2810 | /* Sign extend the operands. */ |
| 2811 | ax_ext (expr, addr_size_bits); |
| 2812 | ax_simple (expr, aop_swap); |
| 2813 | ax_ext (expr, addr_size_bits); |
| 2814 | ax_simple (expr, aop_swap); |
| 2815 | ax_simple (expr, aop_div_signed); |
| 2816 | break; |
| 2817 | |
| 2818 | case DW_OP_minus: |
| 2819 | ax_simple (expr, aop_sub); |
| 2820 | break; |
| 2821 | |
| 2822 | case DW_OP_mod: |
| 2823 | ax_simple (expr, aop_rem_unsigned); |
| 2824 | break; |
| 2825 | |
| 2826 | case DW_OP_mul: |
| 2827 | ax_simple (expr, aop_mul); |
| 2828 | break; |
| 2829 | |
| 2830 | case DW_OP_or: |
| 2831 | ax_simple (expr, aop_bit_or); |
| 2832 | break; |
| 2833 | |
| 2834 | case DW_OP_plus: |
| 2835 | ax_simple (expr, aop_add); |
| 2836 | break; |
| 2837 | |
| 2838 | case DW_OP_shl: |
| 2839 | ax_simple (expr, aop_lsh); |
| 2840 | break; |
| 2841 | |
| 2842 | case DW_OP_shr: |
| 2843 | ax_simple (expr, aop_rsh_unsigned); |
| 2844 | break; |
| 2845 | |
| 2846 | case DW_OP_shra: |
| 2847 | ax_simple (expr, aop_rsh_signed); |
| 2848 | break; |
| 2849 | |
| 2850 | case DW_OP_xor: |
| 2851 | ax_simple (expr, aop_bit_xor); |
| 2852 | break; |
| 2853 | |
| 2854 | case DW_OP_le: |
| 2855 | /* Sign extend the operands. */ |
| 2856 | ax_ext (expr, addr_size_bits); |
| 2857 | ax_simple (expr, aop_swap); |
| 2858 | ax_ext (expr, addr_size_bits); |
| 2859 | /* Note no swap here: A <= B is !(B < A). */ |
| 2860 | ax_simple (expr, aop_less_signed); |
| 2861 | ax_simple (expr, aop_log_not); |
| 2862 | break; |
| 2863 | |
| 2864 | case DW_OP_ge: |
| 2865 | /* Sign extend the operands. */ |
| 2866 | ax_ext (expr, addr_size_bits); |
| 2867 | ax_simple (expr, aop_swap); |
| 2868 | ax_ext (expr, addr_size_bits); |
| 2869 | ax_simple (expr, aop_swap); |
| 2870 | /* A >= B is !(A < B). */ |
| 2871 | ax_simple (expr, aop_less_signed); |
| 2872 | ax_simple (expr, aop_log_not); |
| 2873 | break; |
| 2874 | |
| 2875 | case DW_OP_eq: |
| 2876 | /* Sign extend the operands. */ |
| 2877 | ax_ext (expr, addr_size_bits); |
| 2878 | ax_simple (expr, aop_swap); |
| 2879 | ax_ext (expr, addr_size_bits); |
| 2880 | /* No need for a second swap here. */ |
| 2881 | ax_simple (expr, aop_equal); |
| 2882 | break; |
| 2883 | |
| 2884 | case DW_OP_lt: |
| 2885 | /* Sign extend the operands. */ |
| 2886 | ax_ext (expr, addr_size_bits); |
| 2887 | ax_simple (expr, aop_swap); |
| 2888 | ax_ext (expr, addr_size_bits); |
| 2889 | ax_simple (expr, aop_swap); |
| 2890 | ax_simple (expr, aop_less_signed); |
| 2891 | break; |
| 2892 | |
| 2893 | case DW_OP_gt: |
| 2894 | /* Sign extend the operands. */ |
| 2895 | ax_ext (expr, addr_size_bits); |
| 2896 | ax_simple (expr, aop_swap); |
| 2897 | ax_ext (expr, addr_size_bits); |
| 2898 | /* Note no swap here: A > B is B < A. */ |
| 2899 | ax_simple (expr, aop_less_signed); |
| 2900 | break; |
| 2901 | |
| 2902 | case DW_OP_ne: |
| 2903 | /* Sign extend the operands. */ |
| 2904 | ax_ext (expr, addr_size_bits); |
| 2905 | ax_simple (expr, aop_swap); |
| 2906 | ax_ext (expr, addr_size_bits); |
| 2907 | /* No need for a swap here. */ |
| 2908 | ax_simple (expr, aop_equal); |
| 2909 | ax_simple (expr, aop_log_not); |
| 2910 | break; |
| 2911 | |
| 2912 | case DW_OP_call_frame_cfa: |
| 2913 | dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope, per_cu); |
| 2914 | loc->kind = axs_lvalue_memory; |
| 2915 | break; |
| 2916 | |
| 2917 | case DW_OP_GNU_push_tls_address: |
| 2918 | unimplemented (op); |
| 2919 | break; |
| 2920 | |
| 2921 | case DW_OP_skip: |
| 2922 | offset = extract_signed_integer (op_ptr, 2, byte_order); |
| 2923 | op_ptr += 2; |
| 2924 | i = ax_goto (expr, aop_goto); |
| 2925 | VEC_safe_push (int, dw_labels, op_ptr + offset - base); |
| 2926 | VEC_safe_push (int, patches, i); |
| 2927 | break; |
| 2928 | |
| 2929 | case DW_OP_bra: |
| 2930 | offset = extract_signed_integer (op_ptr, 2, byte_order); |
| 2931 | op_ptr += 2; |
| 2932 | /* Zero extend the operand. */ |
| 2933 | ax_zero_ext (expr, addr_size_bits); |
| 2934 | i = ax_goto (expr, aop_if_goto); |
| 2935 | VEC_safe_push (int, dw_labels, op_ptr + offset - base); |
| 2936 | VEC_safe_push (int, patches, i); |
| 2937 | break; |
| 2938 | |
| 2939 | case DW_OP_nop: |
| 2940 | break; |
| 2941 | |
| 2942 | case DW_OP_piece: |
| 2943 | case DW_OP_bit_piece: |
| 2944 | { |
| 2945 | ULONGEST size, offset; |
| 2946 | |
| 2947 | if (op_ptr - 1 == previous_piece) |
| 2948 | error (_("Cannot translate empty pieces to agent expressions")); |
| 2949 | previous_piece = op_ptr - 1; |
| 2950 | |
| 2951 | op_ptr = read_uleb128 (op_ptr, op_end, &size); |
| 2952 | if (op == DW_OP_piece) |
| 2953 | { |
| 2954 | size *= 8; |
| 2955 | offset = 0; |
| 2956 | } |
| 2957 | else |
| 2958 | op_ptr = read_uleb128 (op_ptr, op_end, &offset); |
| 2959 | |
| 2960 | if (bits_collected + size > 8 * sizeof (LONGEST)) |
| 2961 | error (_("Expression pieces exceed word size")); |
| 2962 | |
| 2963 | /* Access the bits. */ |
| 2964 | switch (loc->kind) |
| 2965 | { |
| 2966 | case axs_lvalue_register: |
| 2967 | ax_reg (expr, loc->u.reg); |
| 2968 | break; |
| 2969 | |
| 2970 | case axs_lvalue_memory: |
| 2971 | /* Offset the pointer, if needed. */ |
| 2972 | if (offset > 8) |
| 2973 | { |
| 2974 | ax_const_l (expr, offset / 8); |
| 2975 | ax_simple (expr, aop_add); |
| 2976 | offset %= 8; |
| 2977 | } |
| 2978 | access_memory (arch, expr, size); |
| 2979 | break; |
| 2980 | } |
| 2981 | |
| 2982 | /* For a bits-big-endian target, shift up what we already |
| 2983 | have. For a bits-little-endian target, shift up the |
| 2984 | new data. Note that there is a potential bug here if |
| 2985 | the DWARF expression leaves multiple values on the |
| 2986 | stack. */ |
| 2987 | if (bits_collected > 0) |
| 2988 | { |
| 2989 | if (bits_big_endian) |
| 2990 | { |
| 2991 | ax_simple (expr, aop_swap); |
| 2992 | ax_const_l (expr, size); |
| 2993 | ax_simple (expr, aop_lsh); |
| 2994 | /* We don't need a second swap here, because |
| 2995 | aop_bit_or is symmetric. */ |
| 2996 | } |
| 2997 | else |
| 2998 | { |
| 2999 | ax_const_l (expr, size); |
| 3000 | ax_simple (expr, aop_lsh); |
| 3001 | } |
| 3002 | ax_simple (expr, aop_bit_or); |
| 3003 | } |
| 3004 | |
| 3005 | bits_collected += size; |
| 3006 | loc->kind = axs_rvalue; |
| 3007 | } |
| 3008 | break; |
| 3009 | |
| 3010 | case DW_OP_GNU_uninit: |
| 3011 | unimplemented (op); |
| 3012 | |
| 3013 | case DW_OP_call2: |
| 3014 | case DW_OP_call4: |
| 3015 | { |
| 3016 | struct dwarf2_locexpr_baton block; |
| 3017 | int size = (op == DW_OP_call2 ? 2 : 4); |
| 3018 | cu_offset offset; |
| 3019 | |
| 3020 | uoffset = extract_unsigned_integer (op_ptr, size, byte_order); |
| 3021 | op_ptr += size; |
| 3022 | |
| 3023 | offset.cu_off = uoffset; |
| 3024 | block = dwarf2_fetch_die_location_block (offset, per_cu, |
| 3025 | get_ax_pc, expr); |
| 3026 | |
| 3027 | /* DW_OP_call_ref is currently not supported. */ |
| 3028 | gdb_assert (block.per_cu == per_cu); |
| 3029 | |
| 3030 | dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, |
| 3031 | block.data, block.data + block.size, |
| 3032 | per_cu); |
| 3033 | } |
| 3034 | break; |
| 3035 | |
| 3036 | case DW_OP_call_ref: |
| 3037 | unimplemented (op); |
| 3038 | |
| 3039 | default: |
| 3040 | unimplemented (op); |
| 3041 | } |
| 3042 | } |
| 3043 | |
| 3044 | /* Patch all the branches we emitted. */ |
| 3045 | for (i = 0; i < VEC_length (int, patches); ++i) |
| 3046 | { |
| 3047 | int targ = offsets[VEC_index (int, dw_labels, i)]; |
| 3048 | if (targ == -1) |
| 3049 | internal_error (__FILE__, __LINE__, _("invalid label")); |
| 3050 | ax_label (expr, VEC_index (int, patches, i), targ); |
| 3051 | } |
| 3052 | |
| 3053 | do_cleanups (cleanups); |
| 3054 | } |
| 3055 | |
| 3056 | \f |
| 3057 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression |
| 3058 | evaluator to calculate the location. */ |
| 3059 | static struct value * |
| 3060 | locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) |
| 3061 | { |
| 3062 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3063 | struct value *val; |
| 3064 | |
| 3065 | val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data, |
| 3066 | dlbaton->size, dlbaton->per_cu); |
| 3067 | |
| 3068 | return val; |
| 3069 | } |
| 3070 | |
| 3071 | /* Return the value of SYMBOL in FRAME at (callee) FRAME's function |
| 3072 | entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR |
| 3073 | will be thrown. */ |
| 3074 | |
| 3075 | static struct value * |
| 3076 | locexpr_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) |
| 3077 | { |
| 3078 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3079 | |
| 3080 | return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, dlbaton->data, |
| 3081 | dlbaton->size); |
| 3082 | } |
| 3083 | |
| 3084 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ |
| 3085 | static int |
| 3086 | locexpr_read_needs_frame (struct symbol *symbol) |
| 3087 | { |
| 3088 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3089 | |
| 3090 | return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size, |
| 3091 | dlbaton->per_cu); |
| 3092 | } |
| 3093 | |
| 3094 | /* Return true if DATA points to the end of a piece. END is one past |
| 3095 | the last byte in the expression. */ |
| 3096 | |
| 3097 | static int |
| 3098 | piece_end_p (const gdb_byte *data, const gdb_byte *end) |
| 3099 | { |
| 3100 | return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece; |
| 3101 | } |
| 3102 | |
| 3103 | /* Helper for locexpr_describe_location_piece that finds the name of a |
| 3104 | DWARF register. */ |
| 3105 | |
| 3106 | static const char * |
| 3107 | locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum) |
| 3108 | { |
| 3109 | int regnum; |
| 3110 | |
| 3111 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum); |
| 3112 | return gdbarch_register_name (gdbarch, regnum); |
| 3113 | } |
| 3114 | |
| 3115 | /* Nicely describe a single piece of a location, returning an updated |
| 3116 | position in the bytecode sequence. This function cannot recognize |
| 3117 | all locations; if a location is not recognized, it simply returns |
| 3118 | DATA. */ |
| 3119 | |
| 3120 | static const gdb_byte * |
| 3121 | locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, |
| 3122 | CORE_ADDR addr, struct objfile *objfile, |
| 3123 | const gdb_byte *data, const gdb_byte *end, |
| 3124 | unsigned int addr_size) |
| 3125 | { |
| 3126 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 3127 | |
| 3128 | if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) |
| 3129 | { |
| 3130 | fprintf_filtered (stream, _("a variable in $%s"), |
| 3131 | locexpr_regname (gdbarch, data[0] - DW_OP_reg0)); |
| 3132 | data += 1; |
| 3133 | } |
| 3134 | else if (data[0] == DW_OP_regx) |
| 3135 | { |
| 3136 | ULONGEST reg; |
| 3137 | |
| 3138 | data = read_uleb128 (data + 1, end, ®); |
| 3139 | fprintf_filtered (stream, _("a variable in $%s"), |
| 3140 | locexpr_regname (gdbarch, reg)); |
| 3141 | } |
| 3142 | else if (data[0] == DW_OP_fbreg) |
| 3143 | { |
| 3144 | struct block *b; |
| 3145 | struct symbol *framefunc; |
| 3146 | int frame_reg = 0; |
| 3147 | LONGEST frame_offset; |
| 3148 | const gdb_byte *base_data, *new_data, *save_data = data; |
| 3149 | size_t base_size; |
| 3150 | LONGEST base_offset = 0; |
| 3151 | |
| 3152 | new_data = read_sleb128 (data + 1, end, &frame_offset); |
| 3153 | if (!piece_end_p (new_data, end)) |
| 3154 | return data; |
| 3155 | data = new_data; |
| 3156 | |
| 3157 | b = block_for_pc (addr); |
| 3158 | |
| 3159 | if (!b) |
| 3160 | error (_("No block found for address for symbol \"%s\"."), |
| 3161 | SYMBOL_PRINT_NAME (symbol)); |
| 3162 | |
| 3163 | framefunc = block_linkage_function (b); |
| 3164 | |
| 3165 | if (!framefunc) |
| 3166 | error (_("No function found for block for symbol \"%s\"."), |
| 3167 | SYMBOL_PRINT_NAME (symbol)); |
| 3168 | |
| 3169 | dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size); |
| 3170 | |
| 3171 | if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) |
| 3172 | { |
| 3173 | const gdb_byte *buf_end; |
| 3174 | |
| 3175 | frame_reg = base_data[0] - DW_OP_breg0; |
| 3176 | buf_end = read_sleb128 (base_data + 1, |
| 3177 | base_data + base_size, &base_offset); |
| 3178 | if (buf_end != base_data + base_size) |
| 3179 | error (_("Unexpected opcode after " |
| 3180 | "DW_OP_breg%u for symbol \"%s\"."), |
| 3181 | frame_reg, SYMBOL_PRINT_NAME (symbol)); |
| 3182 | } |
| 3183 | else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) |
| 3184 | { |
| 3185 | /* The frame base is just the register, with no offset. */ |
| 3186 | frame_reg = base_data[0] - DW_OP_reg0; |
| 3187 | base_offset = 0; |
| 3188 | } |
| 3189 | else |
| 3190 | { |
| 3191 | /* We don't know what to do with the frame base expression, |
| 3192 | so we can't trace this variable; give up. */ |
| 3193 | return save_data; |
| 3194 | } |
| 3195 | |
| 3196 | fprintf_filtered (stream, |
| 3197 | _("a variable at frame base reg $%s offset %s+%s"), |
| 3198 | locexpr_regname (gdbarch, frame_reg), |
| 3199 | plongest (base_offset), plongest (frame_offset)); |
| 3200 | } |
| 3201 | else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31 |
| 3202 | && piece_end_p (data, end)) |
| 3203 | { |
| 3204 | LONGEST offset; |
| 3205 | |
| 3206 | data = read_sleb128 (data + 1, end, &offset); |
| 3207 | |
| 3208 | fprintf_filtered (stream, |
| 3209 | _("a variable at offset %s from base reg $%s"), |
| 3210 | plongest (offset), |
| 3211 | locexpr_regname (gdbarch, data[0] - DW_OP_breg0)); |
| 3212 | } |
| 3213 | |
| 3214 | /* The location expression for a TLS variable looks like this (on a |
| 3215 | 64-bit LE machine): |
| 3216 | |
| 3217 | DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 |
| 3218 | (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) |
| 3219 | |
| 3220 | 0x3 is the encoding for DW_OP_addr, which has an operand as long |
| 3221 | as the size of an address on the target machine (here is 8 |
| 3222 | bytes). Note that more recent version of GCC emit DW_OP_const4u |
| 3223 | or DW_OP_const8u, depending on address size, rather than |
| 3224 | DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address. |
| 3225 | The operand represents the offset at which the variable is within |
| 3226 | the thread local storage. */ |
| 3227 | |
| 3228 | else if (data + 1 + addr_size < end |
| 3229 | && (data[0] == DW_OP_addr |
| 3230 | || (addr_size == 4 && data[0] == DW_OP_const4u) |
| 3231 | || (addr_size == 8 && data[0] == DW_OP_const8u)) |
| 3232 | && data[1 + addr_size] == DW_OP_GNU_push_tls_address |
| 3233 | && piece_end_p (data + 2 + addr_size, end)) |
| 3234 | { |
| 3235 | ULONGEST offset; |
| 3236 | offset = extract_unsigned_integer (data + 1, addr_size, |
| 3237 | gdbarch_byte_order (gdbarch)); |
| 3238 | |
| 3239 | fprintf_filtered (stream, |
| 3240 | _("a thread-local variable at offset 0x%s " |
| 3241 | "in the thread-local storage for `%s'"), |
| 3242 | phex_nz (offset, addr_size), objfile->name); |
| 3243 | |
| 3244 | data += 1 + addr_size + 1; |
| 3245 | } |
| 3246 | else if (data[0] >= DW_OP_lit0 |
| 3247 | && data[0] <= DW_OP_lit31 |
| 3248 | && data + 1 < end |
| 3249 | && data[1] == DW_OP_stack_value) |
| 3250 | { |
| 3251 | fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0); |
| 3252 | data += 2; |
| 3253 | } |
| 3254 | |
| 3255 | return data; |
| 3256 | } |
| 3257 | |
| 3258 | /* Disassemble an expression, stopping at the end of a piece or at the |
| 3259 | end of the expression. Returns a pointer to the next unread byte |
| 3260 | in the input expression. If ALL is nonzero, then this function |
| 3261 | will keep going until it reaches the end of the expression. */ |
| 3262 | |
| 3263 | static const gdb_byte * |
| 3264 | disassemble_dwarf_expression (struct ui_file *stream, |
| 3265 | struct gdbarch *arch, unsigned int addr_size, |
| 3266 | int offset_size, const gdb_byte *start, |
| 3267 | const gdb_byte *data, const gdb_byte *end, |
| 3268 | int indent, int all, |
| 3269 | struct dwarf2_per_cu_data *per_cu) |
| 3270 | { |
| 3271 | while (data < end |
| 3272 | && (all |
| 3273 | || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece))) |
| 3274 | { |
| 3275 | enum dwarf_location_atom op = *data++; |
| 3276 | ULONGEST ul; |
| 3277 | LONGEST l; |
| 3278 | const char *name; |
| 3279 | |
| 3280 | name = dwarf_stack_op_name (op); |
| 3281 | |
| 3282 | if (!name) |
| 3283 | error (_("Unrecognized DWARF opcode 0x%02x at %ld"), |
| 3284 | op, (long) (data - 1 - start)); |
| 3285 | fprintf_filtered (stream, " %*ld: %s", indent + 4, |
| 3286 | (long) (data - 1 - start), name); |
| 3287 | |
| 3288 | switch (op) |
| 3289 | { |
| 3290 | case DW_OP_addr: |
| 3291 | ul = extract_unsigned_integer (data, addr_size, |
| 3292 | gdbarch_byte_order (arch)); |
| 3293 | data += addr_size; |
| 3294 | fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size)); |
| 3295 | break; |
| 3296 | |
| 3297 | case DW_OP_const1u: |
| 3298 | ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch)); |
| 3299 | data += 1; |
| 3300 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3301 | break; |
| 3302 | case DW_OP_const1s: |
| 3303 | l = extract_signed_integer (data, 1, gdbarch_byte_order (arch)); |
| 3304 | data += 1; |
| 3305 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3306 | break; |
| 3307 | case DW_OP_const2u: |
| 3308 | ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); |
| 3309 | data += 2; |
| 3310 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3311 | break; |
| 3312 | case DW_OP_const2s: |
| 3313 | l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| 3314 | data += 2; |
| 3315 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3316 | break; |
| 3317 | case DW_OP_const4u: |
| 3318 | ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); |
| 3319 | data += 4; |
| 3320 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3321 | break; |
| 3322 | case DW_OP_const4s: |
| 3323 | l = extract_signed_integer (data, 4, gdbarch_byte_order (arch)); |
| 3324 | data += 4; |
| 3325 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3326 | break; |
| 3327 | case DW_OP_const8u: |
| 3328 | ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch)); |
| 3329 | data += 8; |
| 3330 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3331 | break; |
| 3332 | case DW_OP_const8s: |
| 3333 | l = extract_signed_integer (data, 8, gdbarch_byte_order (arch)); |
| 3334 | data += 8; |
| 3335 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3336 | break; |
| 3337 | case DW_OP_constu: |
| 3338 | data = read_uleb128 (data, end, &ul); |
| 3339 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3340 | break; |
| 3341 | case DW_OP_consts: |
| 3342 | data = read_sleb128 (data, end, &l); |
| 3343 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3344 | break; |
| 3345 | |
| 3346 | case DW_OP_reg0: |
| 3347 | case DW_OP_reg1: |
| 3348 | case DW_OP_reg2: |
| 3349 | case DW_OP_reg3: |
| 3350 | case DW_OP_reg4: |
| 3351 | case DW_OP_reg5: |
| 3352 | case DW_OP_reg6: |
| 3353 | case DW_OP_reg7: |
| 3354 | case DW_OP_reg8: |
| 3355 | case DW_OP_reg9: |
| 3356 | case DW_OP_reg10: |
| 3357 | case DW_OP_reg11: |
| 3358 | case DW_OP_reg12: |
| 3359 | case DW_OP_reg13: |
| 3360 | case DW_OP_reg14: |
| 3361 | case DW_OP_reg15: |
| 3362 | case DW_OP_reg16: |
| 3363 | case DW_OP_reg17: |
| 3364 | case DW_OP_reg18: |
| 3365 | case DW_OP_reg19: |
| 3366 | case DW_OP_reg20: |
| 3367 | case DW_OP_reg21: |
| 3368 | case DW_OP_reg22: |
| 3369 | case DW_OP_reg23: |
| 3370 | case DW_OP_reg24: |
| 3371 | case DW_OP_reg25: |
| 3372 | case DW_OP_reg26: |
| 3373 | case DW_OP_reg27: |
| 3374 | case DW_OP_reg28: |
| 3375 | case DW_OP_reg29: |
| 3376 | case DW_OP_reg30: |
| 3377 | case DW_OP_reg31: |
| 3378 | fprintf_filtered (stream, " [$%s]", |
| 3379 | locexpr_regname (arch, op - DW_OP_reg0)); |
| 3380 | break; |
| 3381 | |
| 3382 | case DW_OP_regx: |
| 3383 | data = read_uleb128 (data, end, &ul); |
| 3384 | fprintf_filtered (stream, " %s [$%s]", pulongest (ul), |
| 3385 | locexpr_regname (arch, (int) ul)); |
| 3386 | break; |
| 3387 | |
| 3388 | case DW_OP_implicit_value: |
| 3389 | data = read_uleb128 (data, end, &ul); |
| 3390 | data += ul; |
| 3391 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3392 | break; |
| 3393 | |
| 3394 | case DW_OP_breg0: |
| 3395 | case DW_OP_breg1: |
| 3396 | case DW_OP_breg2: |
| 3397 | case DW_OP_breg3: |
| 3398 | case DW_OP_breg4: |
| 3399 | case DW_OP_breg5: |
| 3400 | case DW_OP_breg6: |
| 3401 | case DW_OP_breg7: |
| 3402 | case DW_OP_breg8: |
| 3403 | case DW_OP_breg9: |
| 3404 | case DW_OP_breg10: |
| 3405 | case DW_OP_breg11: |
| 3406 | case DW_OP_breg12: |
| 3407 | case DW_OP_breg13: |
| 3408 | case DW_OP_breg14: |
| 3409 | case DW_OP_breg15: |
| 3410 | case DW_OP_breg16: |
| 3411 | case DW_OP_breg17: |
| 3412 | case DW_OP_breg18: |
| 3413 | case DW_OP_breg19: |
| 3414 | case DW_OP_breg20: |
| 3415 | case DW_OP_breg21: |
| 3416 | case DW_OP_breg22: |
| 3417 | case DW_OP_breg23: |
| 3418 | case DW_OP_breg24: |
| 3419 | case DW_OP_breg25: |
| 3420 | case DW_OP_breg26: |
| 3421 | case DW_OP_breg27: |
| 3422 | case DW_OP_breg28: |
| 3423 | case DW_OP_breg29: |
| 3424 | case DW_OP_breg30: |
| 3425 | case DW_OP_breg31: |
| 3426 | data = read_sleb128 (data, end, &l); |
| 3427 | fprintf_filtered (stream, " %s [$%s]", plongest (l), |
| 3428 | locexpr_regname (arch, op - DW_OP_breg0)); |
| 3429 | break; |
| 3430 | |
| 3431 | case DW_OP_bregx: |
| 3432 | data = read_uleb128 (data, end, &ul); |
| 3433 | data = read_sleb128 (data, end, &l); |
| 3434 | fprintf_filtered (stream, " register %s [$%s] offset %s", |
| 3435 | pulongest (ul), |
| 3436 | locexpr_regname (arch, (int) ul), |
| 3437 | plongest (l)); |
| 3438 | break; |
| 3439 | |
| 3440 | case DW_OP_fbreg: |
| 3441 | data = read_sleb128 (data, end, &l); |
| 3442 | fprintf_filtered (stream, " %s", plongest (l)); |
| 3443 | break; |
| 3444 | |
| 3445 | case DW_OP_xderef_size: |
| 3446 | case DW_OP_deref_size: |
| 3447 | case DW_OP_pick: |
| 3448 | fprintf_filtered (stream, " %d", *data); |
| 3449 | ++data; |
| 3450 | break; |
| 3451 | |
| 3452 | case DW_OP_plus_uconst: |
| 3453 | data = read_uleb128 (data, end, &ul); |
| 3454 | fprintf_filtered (stream, " %s", pulongest (ul)); |
| 3455 | break; |
| 3456 | |
| 3457 | case DW_OP_skip: |
| 3458 | l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| 3459 | data += 2; |
| 3460 | fprintf_filtered (stream, " to %ld", |
| 3461 | (long) (data + l - start)); |
| 3462 | break; |
| 3463 | |
| 3464 | case DW_OP_bra: |
| 3465 | l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| 3466 | data += 2; |
| 3467 | fprintf_filtered (stream, " %ld", |
| 3468 | (long) (data + l - start)); |
| 3469 | break; |
| 3470 | |
| 3471 | case DW_OP_call2: |
| 3472 | ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); |
| 3473 | data += 2; |
| 3474 | fprintf_filtered (stream, " offset %s", phex_nz (ul, 2)); |
| 3475 | break; |
| 3476 | |
| 3477 | case DW_OP_call4: |
| 3478 | ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); |
| 3479 | data += 4; |
| 3480 | fprintf_filtered (stream, " offset %s", phex_nz (ul, 4)); |
| 3481 | break; |
| 3482 | |
| 3483 | case DW_OP_call_ref: |
| 3484 | ul = extract_unsigned_integer (data, offset_size, |
| 3485 | gdbarch_byte_order (arch)); |
| 3486 | data += offset_size; |
| 3487 | fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size)); |
| 3488 | break; |
| 3489 | |
| 3490 | case DW_OP_piece: |
| 3491 | data = read_uleb128 (data, end, &ul); |
| 3492 | fprintf_filtered (stream, " %s (bytes)", pulongest (ul)); |
| 3493 | break; |
| 3494 | |
| 3495 | case DW_OP_bit_piece: |
| 3496 | { |
| 3497 | ULONGEST offset; |
| 3498 | |
| 3499 | data = read_uleb128 (data, end, &ul); |
| 3500 | data = read_uleb128 (data, end, &offset); |
| 3501 | fprintf_filtered (stream, " size %s offset %s (bits)", |
| 3502 | pulongest (ul), pulongest (offset)); |
| 3503 | } |
| 3504 | break; |
| 3505 | |
| 3506 | case DW_OP_GNU_implicit_pointer: |
| 3507 | { |
| 3508 | ul = extract_unsigned_integer (data, offset_size, |
| 3509 | gdbarch_byte_order (arch)); |
| 3510 | data += offset_size; |
| 3511 | |
| 3512 | data = read_sleb128 (data, end, &l); |
| 3513 | |
| 3514 | fprintf_filtered (stream, " DIE %s offset %s", |
| 3515 | phex_nz (ul, offset_size), |
| 3516 | plongest (l)); |
| 3517 | } |
| 3518 | break; |
| 3519 | |
| 3520 | case DW_OP_GNU_deref_type: |
| 3521 | { |
| 3522 | int addr_size = *data++; |
| 3523 | cu_offset offset; |
| 3524 | struct type *type; |
| 3525 | |
| 3526 | data = read_uleb128 (data, end, &ul); |
| 3527 | offset.cu_off = ul; |
| 3528 | type = dwarf2_get_die_type (offset, per_cu); |
| 3529 | fprintf_filtered (stream, "<"); |
| 3530 | type_print (type, "", stream, -1); |
| 3531 | fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset.cu_off, 0), |
| 3532 | addr_size); |
| 3533 | } |
| 3534 | break; |
| 3535 | |
| 3536 | case DW_OP_GNU_const_type: |
| 3537 | { |
| 3538 | cu_offset type_die; |
| 3539 | struct type *type; |
| 3540 | |
| 3541 | data = read_uleb128 (data, end, &ul); |
| 3542 | type_die.cu_off = ul; |
| 3543 | type = dwarf2_get_die_type (type_die, per_cu); |
| 3544 | fprintf_filtered (stream, "<"); |
| 3545 | type_print (type, "", stream, -1); |
| 3546 | fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); |
| 3547 | } |
| 3548 | break; |
| 3549 | |
| 3550 | case DW_OP_GNU_regval_type: |
| 3551 | { |
| 3552 | ULONGEST reg; |
| 3553 | cu_offset type_die; |
| 3554 | struct type *type; |
| 3555 | |
| 3556 | data = read_uleb128 (data, end, ®); |
| 3557 | data = read_uleb128 (data, end, &ul); |
| 3558 | type_die.cu_off = ul; |
| 3559 | |
| 3560 | type = dwarf2_get_die_type (type_die, per_cu); |
| 3561 | fprintf_filtered (stream, "<"); |
| 3562 | type_print (type, "", stream, -1); |
| 3563 | fprintf_filtered (stream, " [0x%s]> [$%s]", |
| 3564 | phex_nz (type_die.cu_off, 0), |
| 3565 | locexpr_regname (arch, reg)); |
| 3566 | } |
| 3567 | break; |
| 3568 | |
| 3569 | case DW_OP_GNU_convert: |
| 3570 | case DW_OP_GNU_reinterpret: |
| 3571 | { |
| 3572 | cu_offset type_die; |
| 3573 | |
| 3574 | data = read_uleb128 (data, end, &ul); |
| 3575 | type_die.cu_off = ul; |
| 3576 | |
| 3577 | if (type_die.cu_off == 0) |
| 3578 | fprintf_filtered (stream, "<0>"); |
| 3579 | else |
| 3580 | { |
| 3581 | struct type *type; |
| 3582 | |
| 3583 | type = dwarf2_get_die_type (type_die, per_cu); |
| 3584 | fprintf_filtered (stream, "<"); |
| 3585 | type_print (type, "", stream, -1); |
| 3586 | fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); |
| 3587 | } |
| 3588 | } |
| 3589 | break; |
| 3590 | |
| 3591 | case DW_OP_GNU_entry_value: |
| 3592 | data = read_uleb128 (data, end, &ul); |
| 3593 | fputc_filtered ('\n', stream); |
| 3594 | disassemble_dwarf_expression (stream, arch, addr_size, offset_size, |
| 3595 | start, data, data + ul, indent + 2, |
| 3596 | all, per_cu); |
| 3597 | data += ul; |
| 3598 | continue; |
| 3599 | } |
| 3600 | |
| 3601 | fprintf_filtered (stream, "\n"); |
| 3602 | } |
| 3603 | |
| 3604 | return data; |
| 3605 | } |
| 3606 | |
| 3607 | /* Describe a single location, which may in turn consist of multiple |
| 3608 | pieces. */ |
| 3609 | |
| 3610 | static void |
| 3611 | locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, |
| 3612 | struct ui_file *stream, |
| 3613 | const gdb_byte *data, int size, |
| 3614 | struct objfile *objfile, unsigned int addr_size, |
| 3615 | int offset_size, struct dwarf2_per_cu_data *per_cu) |
| 3616 | { |
| 3617 | const gdb_byte *end = data + size; |
| 3618 | int first_piece = 1, bad = 0; |
| 3619 | |
| 3620 | while (data < end) |
| 3621 | { |
| 3622 | const gdb_byte *here = data; |
| 3623 | int disassemble = 1; |
| 3624 | |
| 3625 | if (first_piece) |
| 3626 | first_piece = 0; |
| 3627 | else |
| 3628 | fprintf_filtered (stream, _(", and ")); |
| 3629 | |
| 3630 | if (!dwarf2_always_disassemble) |
| 3631 | { |
| 3632 | data = locexpr_describe_location_piece (symbol, stream, |
| 3633 | addr, objfile, |
| 3634 | data, end, addr_size); |
| 3635 | /* If we printed anything, or if we have an empty piece, |
| 3636 | then don't disassemble. */ |
| 3637 | if (data != here |
| 3638 | || data[0] == DW_OP_piece |
| 3639 | || data[0] == DW_OP_bit_piece) |
| 3640 | disassemble = 0; |
| 3641 | } |
| 3642 | if (disassemble) |
| 3643 | { |
| 3644 | fprintf_filtered (stream, _("a complex DWARF expression:\n")); |
| 3645 | data = disassemble_dwarf_expression (stream, |
| 3646 | get_objfile_arch (objfile), |
| 3647 | addr_size, offset_size, data, |
| 3648 | data, end, 0, |
| 3649 | dwarf2_always_disassemble, |
| 3650 | per_cu); |
| 3651 | } |
| 3652 | |
| 3653 | if (data < end) |
| 3654 | { |
| 3655 | int empty = data == here; |
| 3656 | |
| 3657 | if (disassemble) |
| 3658 | fprintf_filtered (stream, " "); |
| 3659 | if (data[0] == DW_OP_piece) |
| 3660 | { |
| 3661 | ULONGEST bytes; |
| 3662 | |
| 3663 | data = read_uleb128 (data + 1, end, &bytes); |
| 3664 | |
| 3665 | if (empty) |
| 3666 | fprintf_filtered (stream, _("an empty %s-byte piece"), |
| 3667 | pulongest (bytes)); |
| 3668 | else |
| 3669 | fprintf_filtered (stream, _(" [%s-byte piece]"), |
| 3670 | pulongest (bytes)); |
| 3671 | } |
| 3672 | else if (data[0] == DW_OP_bit_piece) |
| 3673 | { |
| 3674 | ULONGEST bits, offset; |
| 3675 | |
| 3676 | data = read_uleb128 (data + 1, end, &bits); |
| 3677 | data = read_uleb128 (data, end, &offset); |
| 3678 | |
| 3679 | if (empty) |
| 3680 | fprintf_filtered (stream, |
| 3681 | _("an empty %s-bit piece"), |
| 3682 | pulongest (bits)); |
| 3683 | else |
| 3684 | fprintf_filtered (stream, |
| 3685 | _(" [%s-bit piece, offset %s bits]"), |
| 3686 | pulongest (bits), pulongest (offset)); |
| 3687 | } |
| 3688 | else |
| 3689 | { |
| 3690 | bad = 1; |
| 3691 | break; |
| 3692 | } |
| 3693 | } |
| 3694 | } |
| 3695 | |
| 3696 | if (bad || data > end) |
| 3697 | error (_("Corrupted DWARF2 expression for \"%s\"."), |
| 3698 | SYMBOL_PRINT_NAME (symbol)); |
| 3699 | } |
| 3700 | |
| 3701 | /* Print a natural-language description of SYMBOL to STREAM. This |
| 3702 | version is for a symbol with a single location. */ |
| 3703 | |
| 3704 | static void |
| 3705 | locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, |
| 3706 | struct ui_file *stream) |
| 3707 | { |
| 3708 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3709 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); |
| 3710 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| 3711 | int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); |
| 3712 | |
| 3713 | locexpr_describe_location_1 (symbol, addr, stream, |
| 3714 | dlbaton->data, dlbaton->size, |
| 3715 | objfile, addr_size, offset_size, |
| 3716 | dlbaton->per_cu); |
| 3717 | } |
| 3718 | |
| 3719 | /* Describe the location of SYMBOL as an agent value in VALUE, generating |
| 3720 | any necessary bytecode in AX. */ |
| 3721 | |
| 3722 | static void |
| 3723 | locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
| 3724 | struct agent_expr *ax, struct axs_value *value) |
| 3725 | { |
| 3726 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3727 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| 3728 | |
| 3729 | if (dlbaton->size == 0) |
| 3730 | value->optimized_out = 1; |
| 3731 | else |
| 3732 | dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, |
| 3733 | dlbaton->data, dlbaton->data + dlbaton->size, |
| 3734 | dlbaton->per_cu); |
| 3735 | } |
| 3736 | |
| 3737 | /* The set of location functions used with the DWARF-2 expression |
| 3738 | evaluator. */ |
| 3739 | const struct symbol_computed_ops dwarf2_locexpr_funcs = { |
| 3740 | locexpr_read_variable, |
| 3741 | locexpr_read_variable_at_entry, |
| 3742 | locexpr_read_needs_frame, |
| 3743 | locexpr_describe_location, |
| 3744 | locexpr_tracepoint_var_ref |
| 3745 | }; |
| 3746 | |
| 3747 | |
| 3748 | /* Wrapper functions for location lists. These generally find |
| 3749 | the appropriate location expression and call something above. */ |
| 3750 | |
| 3751 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression |
| 3752 | evaluator to calculate the location. */ |
| 3753 | static struct value * |
| 3754 | loclist_read_variable (struct symbol *symbol, struct frame_info *frame) |
| 3755 | { |
| 3756 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3757 | struct value *val; |
| 3758 | const gdb_byte *data; |
| 3759 | size_t size; |
| 3760 | CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0; |
| 3761 | |
| 3762 | data = dwarf2_find_location_expression (dlbaton, &size, pc); |
| 3763 | val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size, |
| 3764 | dlbaton->per_cu); |
| 3765 | |
| 3766 | return val; |
| 3767 | } |
| 3768 | |
| 3769 | /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function |
| 3770 | entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR |
| 3771 | will be thrown. |
| 3772 | |
| 3773 | Function always returns non-NULL value, it may be marked optimized out if |
| 3774 | inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR |
| 3775 | if it cannot resolve the parameter for any reason. */ |
| 3776 | |
| 3777 | static struct value * |
| 3778 | loclist_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) |
| 3779 | { |
| 3780 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3781 | const gdb_byte *data; |
| 3782 | size_t size; |
| 3783 | CORE_ADDR pc; |
| 3784 | |
| 3785 | if (frame == NULL || !get_frame_func_if_available (frame, &pc)) |
| 3786 | return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); |
| 3787 | |
| 3788 | data = dwarf2_find_location_expression (dlbaton, &size, pc); |
| 3789 | if (data == NULL) |
| 3790 | return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); |
| 3791 | |
| 3792 | return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, data, size); |
| 3793 | } |
| 3794 | |
| 3795 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ |
| 3796 | static int |
| 3797 | loclist_read_needs_frame (struct symbol *symbol) |
| 3798 | { |
| 3799 | /* If there's a location list, then assume we need to have a frame |
| 3800 | to choose the appropriate location expression. With tracking of |
| 3801 | global variables this is not necessarily true, but such tracking |
| 3802 | is disabled in GCC at the moment until we figure out how to |
| 3803 | represent it. */ |
| 3804 | |
| 3805 | return 1; |
| 3806 | } |
| 3807 | |
| 3808 | /* Print a natural-language description of SYMBOL to STREAM. This |
| 3809 | version applies when there is a list of different locations, each |
| 3810 | with a specified address range. */ |
| 3811 | |
| 3812 | static void |
| 3813 | loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, |
| 3814 | struct ui_file *stream) |
| 3815 | { |
| 3816 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3817 | CORE_ADDR low, high; |
| 3818 | const gdb_byte *loc_ptr, *buf_end; |
| 3819 | int length, first = 1; |
| 3820 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); |
| 3821 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 3822 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 3823 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| 3824 | int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); |
| 3825 | int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); |
| 3826 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); |
| 3827 | /* Adjust base_address for relocatable objects. */ |
| 3828 | CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu); |
| 3829 | CORE_ADDR base_address = dlbaton->base_address + base_offset; |
| 3830 | |
| 3831 | loc_ptr = dlbaton->data; |
| 3832 | buf_end = dlbaton->data + dlbaton->size; |
| 3833 | |
| 3834 | fprintf_filtered (stream, _("multi-location:\n")); |
| 3835 | |
| 3836 | /* Iterate through locations until we run out. */ |
| 3837 | while (1) |
| 3838 | { |
| 3839 | if (buf_end - loc_ptr < 2 * addr_size) |
| 3840 | error (_("Corrupted DWARF expression for symbol \"%s\"."), |
| 3841 | SYMBOL_PRINT_NAME (symbol)); |
| 3842 | |
| 3843 | if (signed_addr_p) |
| 3844 | low = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| 3845 | else |
| 3846 | low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| 3847 | loc_ptr += addr_size; |
| 3848 | |
| 3849 | if (signed_addr_p) |
| 3850 | high = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| 3851 | else |
| 3852 | high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| 3853 | loc_ptr += addr_size; |
| 3854 | |
| 3855 | /* A base-address-selection entry. */ |
| 3856 | if ((low & base_mask) == base_mask) |
| 3857 | { |
| 3858 | base_address = high + base_offset; |
| 3859 | fprintf_filtered (stream, _(" Base address %s"), |
| 3860 | paddress (gdbarch, base_address)); |
| 3861 | continue; |
| 3862 | } |
| 3863 | |
| 3864 | /* An end-of-list entry. */ |
| 3865 | if (low == 0 && high == 0) |
| 3866 | break; |
| 3867 | |
| 3868 | /* Otherwise, a location expression entry. */ |
| 3869 | low += base_address; |
| 3870 | high += base_address; |
| 3871 | |
| 3872 | length = extract_unsigned_integer (loc_ptr, 2, byte_order); |
| 3873 | loc_ptr += 2; |
| 3874 | |
| 3875 | /* (It would improve readability to print only the minimum |
| 3876 | necessary digits of the second number of the range.) */ |
| 3877 | fprintf_filtered (stream, _(" Range %s-%s: "), |
| 3878 | paddress (gdbarch, low), paddress (gdbarch, high)); |
| 3879 | |
| 3880 | /* Now describe this particular location. */ |
| 3881 | locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, |
| 3882 | objfile, addr_size, offset_size, |
| 3883 | dlbaton->per_cu); |
| 3884 | |
| 3885 | fprintf_filtered (stream, "\n"); |
| 3886 | |
| 3887 | loc_ptr += length; |
| 3888 | } |
| 3889 | } |
| 3890 | |
| 3891 | /* Describe the location of SYMBOL as an agent value in VALUE, generating |
| 3892 | any necessary bytecode in AX. */ |
| 3893 | static void |
| 3894 | loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
| 3895 | struct agent_expr *ax, struct axs_value *value) |
| 3896 | { |
| 3897 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
| 3898 | const gdb_byte *data; |
| 3899 | size_t size; |
| 3900 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| 3901 | |
| 3902 | data = dwarf2_find_location_expression (dlbaton, &size, ax->scope); |
| 3903 | if (size == 0) |
| 3904 | value->optimized_out = 1; |
| 3905 | else |
| 3906 | dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size, |
| 3907 | dlbaton->per_cu); |
| 3908 | } |
| 3909 | |
| 3910 | /* The set of location functions used with the DWARF-2 expression |
| 3911 | evaluator and location lists. */ |
| 3912 | const struct symbol_computed_ops dwarf2_loclist_funcs = { |
| 3913 | loclist_read_variable, |
| 3914 | loclist_read_variable_at_entry, |
| 3915 | loclist_read_needs_frame, |
| 3916 | loclist_describe_location, |
| 3917 | loclist_tracepoint_var_ref |
| 3918 | }; |
| 3919 | |
| 3920 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 3921 | extern initialize_file_ftype _initialize_dwarf2loc; |
| 3922 | |
| 3923 | void |
| 3924 | _initialize_dwarf2loc (void) |
| 3925 | { |
| 3926 | add_setshow_zinteger_cmd ("entry-values", class_maintenance, |
| 3927 | &entry_values_debug, |
| 3928 | _("Set entry values and tail call frames " |
| 3929 | "debugging."), |
| 3930 | _("Show entry values and tail call frames " |
| 3931 | "debugging."), |
| 3932 | _("When non-zero, the process of determining " |
| 3933 | "parameter values from function entry point " |
| 3934 | "and tail call frames will be printed."), |
| 3935 | NULL, |
| 3936 | show_entry_values_debug, |
| 3937 | &setdebuglist, &showdebuglist); |
| 3938 | } |