| 1 | /* Support for printing C values for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986, 1988-1989, 1991-2001, 2003, 2005-2012 Free |
| 4 | Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdb_string.h" |
| 23 | #include "symtab.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "expression.h" |
| 26 | #include "value.h" |
| 27 | #include "valprint.h" |
| 28 | #include "language.h" |
| 29 | #include "c-lang.h" |
| 30 | #include "cp-abi.h" |
| 31 | #include "target.h" |
| 32 | \f |
| 33 | |
| 34 | /* A helper for c_textual_element_type. This checks the name of the |
| 35 | typedef. This is bogus but it isn't apparent that the compiler |
| 36 | provides us the help we may need. */ |
| 37 | |
| 38 | static int |
| 39 | textual_name (const char *name) |
| 40 | { |
| 41 | return (!strcmp (name, "wchar_t") |
| 42 | || !strcmp (name, "char16_t") |
| 43 | || !strcmp (name, "char32_t")); |
| 44 | } |
| 45 | |
| 46 | /* Apply a heuristic to decide whether an array of TYPE or a pointer |
| 47 | to TYPE should be printed as a textual string. Return non-zero if |
| 48 | it should, or zero if it should be treated as an array of integers |
| 49 | or pointer to integers. FORMAT is the current format letter, or 0 |
| 50 | if none. |
| 51 | |
| 52 | We guess that "char" is a character. Explicitly signed and |
| 53 | unsigned character types are also characters. Integer data from |
| 54 | vector types is not. The user can override this by using the /s |
| 55 | format letter. */ |
| 56 | |
| 57 | int |
| 58 | c_textual_element_type (struct type *type, char format) |
| 59 | { |
| 60 | struct type *true_type, *iter_type; |
| 61 | |
| 62 | if (format != 0 && format != 's') |
| 63 | return 0; |
| 64 | |
| 65 | /* We also rely on this for its side effect of setting up all the |
| 66 | typedef pointers. */ |
| 67 | true_type = check_typedef (type); |
| 68 | |
| 69 | /* TYPE_CODE_CHAR is always textual. */ |
| 70 | if (TYPE_CODE (true_type) == TYPE_CODE_CHAR) |
| 71 | return 1; |
| 72 | |
| 73 | /* Any other character-like types must be integral. */ |
| 74 | if (TYPE_CODE (true_type) != TYPE_CODE_INT) |
| 75 | return 0; |
| 76 | |
| 77 | /* We peel typedefs one by one, looking for a match. */ |
| 78 | iter_type = type; |
| 79 | while (iter_type) |
| 80 | { |
| 81 | /* Check the name of the type. */ |
| 82 | if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type))) |
| 83 | return 1; |
| 84 | |
| 85 | if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF) |
| 86 | break; |
| 87 | |
| 88 | /* Peel a single typedef. If the typedef doesn't have a target |
| 89 | type, we use check_typedef and hope the result is ok -- it |
| 90 | might be for C++, where wchar_t is a built-in type. */ |
| 91 | if (TYPE_TARGET_TYPE (iter_type)) |
| 92 | iter_type = TYPE_TARGET_TYPE (iter_type); |
| 93 | else |
| 94 | iter_type = check_typedef (iter_type); |
| 95 | } |
| 96 | |
| 97 | if (format == 's') |
| 98 | { |
| 99 | /* Print this as a string if we can manage it. For now, no wide |
| 100 | character support. */ |
| 101 | if (TYPE_CODE (true_type) == TYPE_CODE_INT |
| 102 | && TYPE_LENGTH (true_type) == 1) |
| 103 | return 1; |
| 104 | } |
| 105 | else |
| 106 | { |
| 107 | /* If a one-byte TYPE_CODE_INT is missing the not-a-character |
| 108 | flag, then we treat it as text; otherwise, we assume it's |
| 109 | being used as data. */ |
| 110 | if (TYPE_CODE (true_type) == TYPE_CODE_INT |
| 111 | && TYPE_LENGTH (true_type) == 1 |
| 112 | && !TYPE_NOTTEXT (true_type)) |
| 113 | return 1; |
| 114 | } |
| 115 | |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | /* Decorations for C. */ |
| 120 | |
| 121 | static const struct generic_val_print_decorations c_decorations = |
| 122 | { |
| 123 | "", |
| 124 | " + ", |
| 125 | " * I", |
| 126 | "true", |
| 127 | "false", |
| 128 | "void" |
| 129 | }; |
| 130 | |
| 131 | /* See val_print for a description of the various parameters of this |
| 132 | function; they are identical. */ |
| 133 | |
| 134 | void |
| 135 | c_val_print (struct type *type, const gdb_byte *valaddr, |
| 136 | int embedded_offset, CORE_ADDR address, |
| 137 | struct ui_file *stream, int recurse, |
| 138 | const struct value *original_value, |
| 139 | const struct value_print_options *options) |
| 140 | { |
| 141 | struct gdbarch *gdbarch = get_type_arch (type); |
| 142 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 143 | unsigned int i = 0; /* Number of characters printed. */ |
| 144 | unsigned len; |
| 145 | struct type *elttype, *unresolved_elttype; |
| 146 | struct type *unresolved_type = type; |
| 147 | unsigned eltlen; |
| 148 | LONGEST val; |
| 149 | CORE_ADDR addr; |
| 150 | |
| 151 | CHECK_TYPEDEF (type); |
| 152 | switch (TYPE_CODE (type)) |
| 153 | { |
| 154 | case TYPE_CODE_ARRAY: |
| 155 | unresolved_elttype = TYPE_TARGET_TYPE (type); |
| 156 | elttype = check_typedef (unresolved_elttype); |
| 157 | if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0) |
| 158 | { |
| 159 | LONGEST low_bound, high_bound; |
| 160 | |
| 161 | if (!get_array_bounds (type, &low_bound, &high_bound)) |
| 162 | error (_("Could not determine the array high bound")); |
| 163 | |
| 164 | eltlen = TYPE_LENGTH (elttype); |
| 165 | len = high_bound - low_bound + 1; |
| 166 | if (options->prettyprint_arrays) |
| 167 | { |
| 168 | print_spaces_filtered (2 + 2 * recurse, stream); |
| 169 | } |
| 170 | |
| 171 | /* Print arrays of textual chars with a string syntax, as |
| 172 | long as the entire array is valid. */ |
| 173 | if (c_textual_element_type (unresolved_elttype, |
| 174 | options->format) |
| 175 | && value_bytes_available (original_value, embedded_offset, |
| 176 | TYPE_LENGTH (type)) |
| 177 | && value_bits_valid (original_value, |
| 178 | TARGET_CHAR_BIT * embedded_offset, |
| 179 | TARGET_CHAR_BIT * TYPE_LENGTH (type))) |
| 180 | { |
| 181 | /* If requested, look for the first null char and only |
| 182 | print elements up to it. */ |
| 183 | if (options->stop_print_at_null) |
| 184 | { |
| 185 | unsigned int temp_len; |
| 186 | |
| 187 | for (temp_len = 0; |
| 188 | (temp_len < len |
| 189 | && temp_len < options->print_max |
| 190 | && extract_unsigned_integer (valaddr + embedded_offset |
| 191 | + temp_len * eltlen, |
| 192 | eltlen, byte_order) != 0); |
| 193 | ++temp_len) |
| 194 | ; |
| 195 | len = temp_len; |
| 196 | } |
| 197 | |
| 198 | LA_PRINT_STRING (stream, unresolved_elttype, |
| 199 | valaddr + embedded_offset, len, |
| 200 | NULL, 0, options); |
| 201 | i = len; |
| 202 | } |
| 203 | else |
| 204 | { |
| 205 | fprintf_filtered (stream, "{"); |
| 206 | /* If this is a virtual function table, print the 0th |
| 207 | entry specially, and the rest of the members |
| 208 | normally. */ |
| 209 | if (cp_is_vtbl_ptr_type (elttype)) |
| 210 | { |
| 211 | i = 1; |
| 212 | fprintf_filtered (stream, _("%d vtable entries"), |
| 213 | len - 1); |
| 214 | } |
| 215 | else |
| 216 | { |
| 217 | i = 0; |
| 218 | } |
| 219 | val_print_array_elements (type, valaddr, embedded_offset, |
| 220 | address, stream, |
| 221 | recurse, original_value, options, i); |
| 222 | fprintf_filtered (stream, "}"); |
| 223 | } |
| 224 | break; |
| 225 | } |
| 226 | /* Array of unspecified length: treat like pointer to first |
| 227 | elt. */ |
| 228 | addr = address + embedded_offset; |
| 229 | goto print_unpacked_pointer; |
| 230 | |
| 231 | case TYPE_CODE_METHODPTR: |
| 232 | cplus_print_method_ptr (valaddr + embedded_offset, type, stream); |
| 233 | break; |
| 234 | |
| 235 | case TYPE_CODE_PTR: |
| 236 | if (options->format && options->format != 's') |
| 237 | { |
| 238 | val_print_scalar_formatted (type, valaddr, embedded_offset, |
| 239 | original_value, options, 0, stream); |
| 240 | break; |
| 241 | } |
| 242 | if (options->vtblprint && cp_is_vtbl_ptr_type (type)) |
| 243 | { |
| 244 | /* Print the unmangled name if desired. */ |
| 245 | /* Print vtable entry - we only get here if we ARE using |
| 246 | -fvtable_thunks. (Otherwise, look under |
| 247 | TYPE_CODE_STRUCT.) */ |
| 248 | CORE_ADDR addr |
| 249 | = extract_typed_address (valaddr + embedded_offset, type); |
| 250 | |
| 251 | print_function_pointer_address (options, gdbarch, addr, stream); |
| 252 | break; |
| 253 | } |
| 254 | unresolved_elttype = TYPE_TARGET_TYPE (type); |
| 255 | elttype = check_typedef (unresolved_elttype); |
| 256 | { |
| 257 | addr = unpack_pointer (type, valaddr + embedded_offset); |
| 258 | print_unpacked_pointer: |
| 259 | |
| 260 | if (TYPE_CODE (elttype) == TYPE_CODE_FUNC) |
| 261 | { |
| 262 | /* Try to print what function it points to. */ |
| 263 | print_function_pointer_address (options, gdbarch, addr, stream); |
| 264 | return; |
| 265 | } |
| 266 | |
| 267 | if (options->addressprint) |
| 268 | fputs_filtered (paddress (gdbarch, addr), stream); |
| 269 | |
| 270 | /* For a pointer to a textual type, also print the string |
| 271 | pointed to, unless pointer is null. */ |
| 272 | |
| 273 | if (c_textual_element_type (unresolved_elttype, |
| 274 | options->format) |
| 275 | && addr != 0) |
| 276 | { |
| 277 | i = val_print_string (unresolved_elttype, NULL, |
| 278 | addr, -1, |
| 279 | stream, options); |
| 280 | } |
| 281 | else if (cp_is_vtbl_member (type)) |
| 282 | { |
| 283 | /* Print vtbl's nicely. */ |
| 284 | CORE_ADDR vt_address = unpack_pointer (type, |
| 285 | valaddr |
| 286 | + embedded_offset); |
| 287 | |
| 288 | struct minimal_symbol *msymbol = |
| 289 | lookup_minimal_symbol_by_pc (vt_address); |
| 290 | if ((msymbol != NULL) |
| 291 | && (vt_address == SYMBOL_VALUE_ADDRESS (msymbol))) |
| 292 | { |
| 293 | fputs_filtered (" <", stream); |
| 294 | fputs_filtered (SYMBOL_PRINT_NAME (msymbol), stream); |
| 295 | fputs_filtered (">", stream); |
| 296 | } |
| 297 | if (vt_address && options->vtblprint) |
| 298 | { |
| 299 | struct value *vt_val; |
| 300 | struct symbol *wsym = (struct symbol *) NULL; |
| 301 | struct type *wtype; |
| 302 | struct block *block = (struct block *) NULL; |
| 303 | int is_this_fld; |
| 304 | |
| 305 | if (msymbol != NULL) |
| 306 | wsym = lookup_symbol (SYMBOL_LINKAGE_NAME (msymbol), |
| 307 | block, VAR_DOMAIN, |
| 308 | &is_this_fld); |
| 309 | |
| 310 | if (wsym) |
| 311 | { |
| 312 | wtype = SYMBOL_TYPE (wsym); |
| 313 | } |
| 314 | else |
| 315 | { |
| 316 | wtype = unresolved_elttype; |
| 317 | } |
| 318 | vt_val = value_at (wtype, vt_address); |
| 319 | common_val_print (vt_val, stream, recurse + 1, |
| 320 | options, current_language); |
| 321 | if (options->pretty) |
| 322 | { |
| 323 | fprintf_filtered (stream, "\n"); |
| 324 | print_spaces_filtered (2 + 2 * recurse, stream); |
| 325 | } |
| 326 | } |
| 327 | } |
| 328 | return; |
| 329 | } |
| 330 | break; |
| 331 | |
| 332 | case TYPE_CODE_UNION: |
| 333 | if (recurse && !options->unionprint) |
| 334 | { |
| 335 | fprintf_filtered (stream, "{...}"); |
| 336 | break; |
| 337 | } |
| 338 | /* Fall through. */ |
| 339 | case TYPE_CODE_STRUCT: |
| 340 | /*FIXME: Abstract this away. */ |
| 341 | if (options->vtblprint && cp_is_vtbl_ptr_type (type)) |
| 342 | { |
| 343 | /* Print the unmangled name if desired. */ |
| 344 | /* Print vtable entry - we only get here if NOT using |
| 345 | -fvtable_thunks. (Otherwise, look under |
| 346 | TYPE_CODE_PTR.) */ |
| 347 | int offset = (embedded_offset |
| 348 | + TYPE_FIELD_BITPOS (type, |
| 349 | VTBL_FNADDR_OFFSET) / 8); |
| 350 | struct type *field_type = TYPE_FIELD_TYPE (type, |
| 351 | VTBL_FNADDR_OFFSET); |
| 352 | CORE_ADDR addr |
| 353 | = extract_typed_address (valaddr + offset, field_type); |
| 354 | |
| 355 | print_function_pointer_address (options, gdbarch, addr, stream); |
| 356 | } |
| 357 | else |
| 358 | cp_print_value_fields_rtti (type, valaddr, |
| 359 | embedded_offset, address, |
| 360 | stream, recurse, |
| 361 | original_value, options, |
| 362 | NULL, 0); |
| 363 | break; |
| 364 | |
| 365 | case TYPE_CODE_INT: |
| 366 | if (options->format || options->output_format) |
| 367 | { |
| 368 | struct value_print_options opts = *options; |
| 369 | |
| 370 | opts.format = (options->format ? options->format |
| 371 | : options->output_format); |
| 372 | val_print_scalar_formatted (type, valaddr, embedded_offset, |
| 373 | original_value, &opts, 0, stream); |
| 374 | } |
| 375 | else |
| 376 | { |
| 377 | val_print_type_code_int (type, valaddr + embedded_offset, |
| 378 | stream); |
| 379 | /* C and C++ has no single byte int type, char is used |
| 380 | instead. Since we don't know whether the value is really |
| 381 | intended to be used as an integer or a character, print |
| 382 | the character equivalent as well. */ |
| 383 | if (c_textual_element_type (unresolved_type, options->format)) |
| 384 | { |
| 385 | fputs_filtered (" ", stream); |
| 386 | LA_PRINT_CHAR (unpack_long (type, valaddr + embedded_offset), |
| 387 | unresolved_type, stream); |
| 388 | } |
| 389 | } |
| 390 | break; |
| 391 | |
| 392 | case TYPE_CODE_MEMBERPTR: |
| 393 | if (!options->format) |
| 394 | { |
| 395 | cp_print_class_member (valaddr + embedded_offset, type, stream, "&"); |
| 396 | break; |
| 397 | } |
| 398 | /* FALLTHROUGH */ |
| 399 | |
| 400 | case TYPE_CODE_REF: |
| 401 | case TYPE_CODE_ENUM: |
| 402 | case TYPE_CODE_FLAGS: |
| 403 | case TYPE_CODE_FUNC: |
| 404 | case TYPE_CODE_METHOD: |
| 405 | case TYPE_CODE_BOOL: |
| 406 | case TYPE_CODE_RANGE: |
| 407 | case TYPE_CODE_FLT: |
| 408 | case TYPE_CODE_DECFLOAT: |
| 409 | case TYPE_CODE_VOID: |
| 410 | case TYPE_CODE_ERROR: |
| 411 | case TYPE_CODE_UNDEF: |
| 412 | case TYPE_CODE_COMPLEX: |
| 413 | case TYPE_CODE_CHAR: |
| 414 | default: |
| 415 | generic_val_print (type, valaddr, embedded_offset, address, |
| 416 | stream, recurse, original_value, options, |
| 417 | &c_decorations); |
| 418 | break; |
| 419 | } |
| 420 | gdb_flush (stream); |
| 421 | } |
| 422 | \f |
| 423 | void |
| 424 | c_value_print (struct value *val, struct ui_file *stream, |
| 425 | const struct value_print_options *options) |
| 426 | { |
| 427 | struct type *type, *real_type, *val_type; |
| 428 | int full, top, using_enc; |
| 429 | struct value_print_options opts = *options; |
| 430 | |
| 431 | opts.deref_ref = 1; |
| 432 | |
| 433 | /* If it is a pointer, indicate what it points to. |
| 434 | |
| 435 | Print type also if it is a reference. |
| 436 | |
| 437 | C++: if it is a member pointer, we will take care |
| 438 | of that when we print it. */ |
| 439 | |
| 440 | /* Preserve the original type before stripping typedefs. We prefer |
| 441 | to pass down the original type when possible, but for local |
| 442 | checks it is better to look past the typedefs. */ |
| 443 | val_type = value_type (val); |
| 444 | type = check_typedef (val_type); |
| 445 | |
| 446 | if (TYPE_CODE (type) == TYPE_CODE_PTR |
| 447 | || TYPE_CODE (type) == TYPE_CODE_REF) |
| 448 | { |
| 449 | /* Hack: remove (char *) for char strings. Their |
| 450 | type is indicated by the quoted string anyway. |
| 451 | (Don't use c_textual_element_type here; quoted strings |
| 452 | are always exactly (char *), (wchar_t *), or the like. */ |
| 453 | if (TYPE_CODE (val_type) == TYPE_CODE_PTR |
| 454 | && TYPE_NAME (val_type) == NULL |
| 455 | && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL |
| 456 | && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)), |
| 457 | "char") == 0 |
| 458 | || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type))))) |
| 459 | { |
| 460 | /* Print nothing. */ |
| 461 | } |
| 462 | else if (options->objectprint |
| 463 | && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS)) |
| 464 | { |
| 465 | |
| 466 | if (TYPE_CODE(type) == TYPE_CODE_REF) |
| 467 | { |
| 468 | /* Copy value, change to pointer, so we don't get an |
| 469 | error about a non-pointer type in |
| 470 | value_rtti_target_type. */ |
| 471 | struct value *temparg; |
| 472 | temparg=value_copy(val); |
| 473 | deprecated_set_value_type |
| 474 | (temparg, lookup_pointer_type (TYPE_TARGET_TYPE (type))); |
| 475 | val = temparg; |
| 476 | } |
| 477 | /* Pointer to class, check real type of object. */ |
| 478 | fprintf_filtered (stream, "("); |
| 479 | |
| 480 | if (value_entirely_available (val)) |
| 481 | { |
| 482 | real_type = value_rtti_indirect_type (val, &full, &top, |
| 483 | &using_enc); |
| 484 | if (real_type) |
| 485 | { |
| 486 | /* RTTI entry found. */ |
| 487 | type = real_type; |
| 488 | |
| 489 | /* Need to adjust pointer value. */ |
| 490 | val = value_from_pointer (type, value_as_address (val) - top); |
| 491 | |
| 492 | /* Note: When we look up RTTI entries, we don't get |
| 493 | any information on const or volatile |
| 494 | attributes. */ |
| 495 | } |
| 496 | } |
| 497 | type_print (type, "", stream, -1); |
| 498 | fprintf_filtered (stream, ") "); |
| 499 | val_type = type; |
| 500 | } |
| 501 | else |
| 502 | { |
| 503 | /* normal case */ |
| 504 | fprintf_filtered (stream, "("); |
| 505 | type_print (value_type (val), "", stream, -1); |
| 506 | fprintf_filtered (stream, ") "); |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | if (!value_initialized (val)) |
| 511 | fprintf_filtered (stream, " [uninitialized] "); |
| 512 | |
| 513 | if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS)) |
| 514 | { |
| 515 | /* Attempt to determine real type of object. */ |
| 516 | real_type = value_rtti_type (val, &full, &top, &using_enc); |
| 517 | if (real_type) |
| 518 | { |
| 519 | /* We have RTTI information, so use it. */ |
| 520 | val = value_full_object (val, real_type, |
| 521 | full, top, using_enc); |
| 522 | fprintf_filtered (stream, "(%s%s) ", |
| 523 | TYPE_NAME (real_type), |
| 524 | full ? "" : _(" [incomplete object]")); |
| 525 | /* Print out object: enclosing type is same as real_type if |
| 526 | full. */ |
| 527 | val_print (value_enclosing_type (val), |
| 528 | value_contents_for_printing (val), 0, |
| 529 | value_address (val), stream, 0, |
| 530 | val, &opts, current_language); |
| 531 | return; |
| 532 | /* Note: When we look up RTTI entries, we don't get any |
| 533 | information on const or volatile attributes. */ |
| 534 | } |
| 535 | else if (type != check_typedef (value_enclosing_type (val))) |
| 536 | { |
| 537 | /* No RTTI information, so let's do our best. */ |
| 538 | fprintf_filtered (stream, "(%s ?) ", |
| 539 | TYPE_NAME (value_enclosing_type (val))); |
| 540 | val_print (value_enclosing_type (val), |
| 541 | value_contents_for_printing (val), 0, |
| 542 | value_address (val), stream, 0, |
| 543 | val, &opts, current_language); |
| 544 | return; |
| 545 | } |
| 546 | /* Otherwise, we end up at the return outside this "if". */ |
| 547 | } |
| 548 | |
| 549 | val_print (val_type, value_contents_for_printing (val), |
| 550 | value_embedded_offset (val), |
| 551 | value_address (val), |
| 552 | stream, 0, |
| 553 | val, &opts, current_language); |
| 554 | } |