1 /* Go language support routines for GDB, the GNU debugger. 2 3 Copyright (C) 2012-2013 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 /* TODO: 21 - split stacks 22 - printing of native types 23 - goroutines 24 - lots more 25 - gccgo mangling needs redoing 26 It's too hard, for example, to know whether one is looking at a mangled 27 Go symbol or not, and their are ambiguities, e.g., the demangler may 28 get passed *any* symbol, including symbols from other languages 29 and including symbols that are already demangled. 30 One thought is to at least add an _G prefix. 31 - 6g mangling isn't supported yet 32 */ 33 34 #include "defs.h" 35 #include "gdb_assert.h" 36 #include "gdb_obstack.h" 37 #include "gdb_string.h" 38 #include "block.h" 39 #include "symtab.h" 40 #include "language.h" 41 #include "go-lang.h" 42 #include "c-lang.h" 43 #include "parser-defs.h" 44 45 #include <ctype.h> 46 47 /* The main function in the main package. */ 48 static const char GO_MAIN_MAIN[] = "main.main"; 49 50 /* Function returning the special symbol name used by Go for the main 51 procedure in the main program if it is found in minimal symbol list. 52 This function tries to find minimal symbols so that it finds them even 53 if the program was compiled without debugging information. */ 54 55 const char * 56 go_main_name (void) 57 { 58 struct minimal_symbol *msym; 59 60 msym = lookup_minimal_symbol (GO_MAIN_MAIN, NULL, NULL); 61 if (msym != NULL) 62 return GO_MAIN_MAIN; 63 64 /* No known entry procedure found, the main program is probably not Go. */ 65 return NULL; 66 } 67 68 /* Return non-zero if TYPE is a gccgo string. 69 We assume CHECK_TYPEDEF has already been done. */ 70 71 static int 72 gccgo_string_p (struct type *type) 73 { 74 /* gccgo strings don't necessarily have a name we can use. */ 75 76 if (TYPE_NFIELDS (type) == 2) 77 { 78 struct type *type0 = TYPE_FIELD_TYPE (type, 0); 79 struct type *type1 = TYPE_FIELD_TYPE (type, 1); 80 81 CHECK_TYPEDEF (type0); 82 CHECK_TYPEDEF (type1); 83 84 if (TYPE_CODE (type0) == TYPE_CODE_PTR 85 && strcmp (TYPE_FIELD_NAME (type, 0), "__data") == 0 86 && TYPE_CODE (type1) == TYPE_CODE_INT 87 && strcmp (TYPE_FIELD_NAME (type, 1), "__length") == 0) 88 { 89 struct type *target_type = TYPE_TARGET_TYPE (type0); 90 91 CHECK_TYPEDEF (target_type); 92 93 if (TYPE_CODE (target_type) == TYPE_CODE_INT 94 && TYPE_LENGTH (target_type) == 1 95 && strcmp (TYPE_NAME (target_type), "uint8") == 0) 96 return 1; 97 } 98 } 99 100 return 0; 101 } 102 103 /* Return non-zero if TYPE is a 6g string. 104 We assume CHECK_TYPEDEF has already been done. */ 105 106 static int 107 sixg_string_p (struct type *type) 108 { 109 if (TYPE_NFIELDS (type) == 2 110 && TYPE_TAG_NAME (type) != NULL 111 && strcmp (TYPE_TAG_NAME (type), "string") == 0) 112 return 1; 113 114 return 0; 115 } 116 117 /* Classify the kind of Go object that TYPE is. 118 TYPE is a TYPE_CODE_STRUCT, used to represent a Go object. */ 119 120 enum go_type 121 go_classify_struct_type (struct type *type) 122 { 123 CHECK_TYPEDEF (type); 124 125 /* Recognize strings as they're useful to be able to print without 126 pretty-printers. */ 127 if (gccgo_string_p (type) 128 || sixg_string_p (type)) 129 return GO_TYPE_STRING; 130 131 return GO_TYPE_NONE; 132 } 133 134 /* Subroutine of unpack_mangled_go_symbol to simplify it. 135 Given "[foo.]bar.baz", store "bar" in *PACKAGEP and "baz" in *OBJECTP. 136 We stomp on the last '.' to nul-terminate "bar". 137 The caller is responsible for memory management. */ 138 139 static void 140 unpack_package_and_object (char *buf, 141 const char **packagep, const char **objectp) 142 { 143 char *last_dot; 144 145 last_dot = strrchr (buf, '.'); 146 gdb_assert (last_dot != NULL); 147 *objectp = last_dot + 1; 148 *last_dot = '\0'; 149 last_dot = strrchr (buf, '.'); 150 if (last_dot != NULL) 151 *packagep = last_dot + 1; 152 else 153 *packagep = buf; 154 } 155 156 /* Given a mangled Go symbol, find its package name, object name, and 157 method type (if present). 158 E.g., for "libgo_net.textproto.String.N33_libgo_net.textproto.ProtocolError" 159 *PACKAGEP = "textproto" 160 *OBJECTP = "String" 161 *METHOD_TYPE_PACKAGEP = "textproto" 162 *METHOD_TYPE_OBJECTP = "ProtocolError" 163 164 Space for the resulting strings is malloc'd in one buffer. 165 PACKAGEP,OBJECTP,METHOD_TYPE* will (typically) point into this buffer. 166 [There are a few exceptions, but the caller is still responsible for 167 freeing the resulting pointer.] 168 A pointer to this buffer is returned, or NULL if symbol isn't a 169 mangled Go symbol. 170 The caller is responsible for freeing the result. 171 172 *METHOD_TYPE_IS_POINTERP is set to a boolean indicating if 173 the method type is a pointer. 174 175 There may be value in returning the outer container, 176 i.e., "net" in the above example, but for now it's not needed. 177 Plus it's currently not straightforward to compute, 178 it comes from -fgo-prefix, and there's no algorithm to compute it. 179 180 If we ever need to unpack the method type, this routine should work 181 for that too. */ 182 183 static char * 184 unpack_mangled_go_symbol (const char *mangled_name, 185 const char **packagep, 186 const char **objectp, 187 const char **method_type_packagep, 188 const char **method_type_objectp, 189 int *method_type_is_pointerp) 190 { 191 char *buf; 192 char *p; 193 int len = strlen (mangled_name); 194 /* Pointer to last digit in "N<digit(s)>_". */ 195 char *saw_digit; 196 /* Pointer to "N" if valid "N<digit(s)>_" found. */ 197 char *method_type; 198 /* Pointer to the first '.'. */ 199 char *first_dot; 200 /* Pointer to the last '.'. */ 201 char *last_dot; 202 /* Non-zero if we saw a pointer indicator. */ 203 int saw_pointer; 204 205 *packagep = *objectp = NULL; 206 *method_type_packagep = *method_type_objectp = NULL; 207 *method_type_is_pointerp = 0; 208 209 /* main.init is mangled specially. */ 210 if (strcmp (mangled_name, "__go_init_main") == 0) 211 { 212 char *package = xstrdup ("main"); 213 214 *packagep = package; 215 *objectp = "init"; 216 return package; 217 } 218 219 /* main.main is mangled specially (missing prefix). */ 220 if (strcmp (mangled_name, "main.main") == 0) 221 { 222 char *package = xstrdup ("main"); 223 224 *packagep = package; 225 *objectp = "main"; 226 return package; 227 } 228 229 /* We may get passed, e.g., "main.T.Foo", which is *not* mangled. 230 Alas it looks exactly like "prefix.package.object." 231 To cope for now we only recognize the following prefixes: 232 233 go: the default 234 libgo_.*: used by gccgo's runtime 235 236 Thus we don't support -fgo-prefix (except as used by the runtime). */ 237 if (strncmp (mangled_name, "go.", 3) != 0 238 && strncmp (mangled_name, "libgo_", 6) != 0) 239 return NULL; 240 241 /* Quick check for whether a search may be fruitful. */ 242 /* Ignore anything with @plt, etc. in it. */ 243 if (strchr (mangled_name, '@') != NULL) 244 return NULL; 245 /* It must have at least two dots. */ 246 first_dot = strchr (mangled_name, '.'); 247 if (first_dot == NULL) 248 return NULL; 249 /* Treat "foo.bar" as unmangled. It can collide with lots of other 250 languages and it's not clear what the consequences are. 251 And except for main.main, all gccgo symbols are at least 252 prefix.package.object. */ 253 last_dot = strrchr (mangled_name, '.'); 254 if (last_dot == first_dot) 255 return NULL; 256 257 /* More quick checks. */ 258 if (last_dot[1] == '\0' /* foo. */ 259 || last_dot[-1] == '.') /* foo..bar */ 260 return NULL; 261 262 /* At this point we've decided we have a mangled Go symbol. */ 263 264 buf = xstrdup (mangled_name); 265 266 /* Search backwards looking for "N<digit(s)>". */ 267 p = buf + len; 268 saw_digit = method_type = NULL; 269 saw_pointer = 0; 270 while (p > buf) 271 { 272 int current = *(const unsigned char *) --p; 273 int current_is_digit = isdigit (current); 274 275 if (saw_digit) 276 { 277 if (current_is_digit) 278 continue; 279 if (current == 'N' 280 && ((p > buf && p[-1] == '.') 281 || (p > buf + 1 && p[-1] == 'p' && p[-2] == '.'))) 282 { 283 if (atoi (p + 1) == strlen (saw_digit + 2)) 284 { 285 if (p[-1] == '.') 286 method_type = p - 1; 287 else 288 { 289 gdb_assert (p[-1] == 'p'); 290 saw_pointer = 1; 291 method_type = p - 2; 292 } 293 break; 294 } 295 } 296 /* Not what we're looking for, reset and keep looking. */ 297 saw_digit = NULL; 298 saw_pointer = 0; 299 continue; 300 } 301 if (current_is_digit && p[1] == '_') 302 { 303 /* Possible start of method "this" [sic] type. */ 304 saw_digit = p; 305 continue; 306 } 307 } 308 309 if (method_type != NULL 310 /* Ensure not something like "..foo". */ 311 && (method_type > buf && method_type[-1] != '.')) 312 { 313 unpack_package_and_object (saw_digit + 2, 314 method_type_packagep, method_type_objectp); 315 *method_type = '\0'; 316 *method_type_is_pointerp = saw_pointer; 317 } 318 319 unpack_package_and_object (buf, packagep, objectp); 320 return buf; 321 } 322 323 /* Implements the la_demangle language_defn routine for language Go. 324 325 N.B. This may get passed *any* symbol, including symbols from other 326 languages and including symbols that are already demangled. 327 Both of these situations are kinda unfortunate, but that's how things 328 are today. 329 330 N.B. This currently only supports gccgo's mangling. 331 332 N.B. gccgo's mangling needs, I think, changing. 333 This demangler can't work in all situations, 334 thus not too much effort is currently put into it. */ 335 336 char * 337 go_demangle (const char *mangled_name, int options) 338 { 339 struct obstack tempbuf; 340 char *result; 341 char *name_buf; 342 const char *package_name; 343 const char *object_name; 344 const char *method_type_package_name; 345 const char *method_type_object_name; 346 int method_type_is_pointer; 347 348 if (mangled_name == NULL) 349 return NULL; 350 351 name_buf = unpack_mangled_go_symbol (mangled_name, 352 &package_name, &object_name, 353 &method_type_package_name, 354 &method_type_object_name, 355 &method_type_is_pointer); 356 if (name_buf == NULL) 357 return NULL; 358 359 obstack_init (&tempbuf); 360 361 /* Print methods as they appear in "method expressions". */ 362 if (method_type_package_name != NULL) 363 { 364 /* FIXME: Seems like we should include package_name here somewhere. */ 365 if (method_type_is_pointer) 366 obstack_grow_str (&tempbuf, "(*"); 367 obstack_grow_str (&tempbuf, method_type_package_name); 368 obstack_grow_str (&tempbuf, "."); 369 obstack_grow_str (&tempbuf, method_type_object_name); 370 if (method_type_is_pointer) 371 obstack_grow_str (&tempbuf, ")"); 372 obstack_grow_str (&tempbuf, "."); 373 obstack_grow_str (&tempbuf, object_name); 374 } 375 else 376 { 377 obstack_grow_str (&tempbuf, package_name); 378 obstack_grow_str (&tempbuf, "."); 379 obstack_grow_str (&tempbuf, object_name); 380 } 381 obstack_grow_str0 (&tempbuf, ""); 382 383 result = xstrdup (obstack_finish (&tempbuf)); 384 obstack_free (&tempbuf, NULL); 385 xfree (name_buf); 386 return result; 387 } 388 389 /* Given a Go symbol, return its package or NULL if unknown. 390 Space for the result is malloc'd, caller must free. */ 391 392 char * 393 go_symbol_package_name (const struct symbol *sym) 394 { 395 const char *mangled_name = SYMBOL_LINKAGE_NAME (sym); 396 const char *package_name; 397 const char *object_name; 398 const char *method_type_package_name; 399 const char *method_type_object_name; 400 int method_type_is_pointer; 401 char *name_buf; 402 char *result; 403 404 gdb_assert (SYMBOL_LANGUAGE (sym) == language_go); 405 name_buf = unpack_mangled_go_symbol (mangled_name, 406 &package_name, &object_name, 407 &method_type_package_name, 408 &method_type_object_name, 409 &method_type_is_pointer); 410 /* Some Go symbols don't have mangled form we interpret (yet). */ 411 if (name_buf == NULL) 412 return NULL; 413 result = xstrdup (package_name); 414 xfree (name_buf); 415 return result; 416 } 417 418 /* Return the package that BLOCK is in, or NULL if there isn't one. 419 Space for the result is malloc'd, caller must free. */ 420 421 char * 422 go_block_package_name (const struct block *block) 423 { 424 while (block != NULL) 425 { 426 struct symbol *function = BLOCK_FUNCTION (block); 427 428 if (function != NULL) 429 { 430 char *package_name = go_symbol_package_name (function); 431 432 if (package_name != NULL) 433 return package_name; 434 435 /* Stop looking if we find a function without a package name. 436 We're most likely outside of Go and thus the concept of the 437 "current" package is gone. */ 438 return NULL; 439 } 440 441 block = BLOCK_SUPERBLOCK (block); 442 } 443 444 return NULL; 445 } 446 447 /* Table mapping opcodes into strings for printing operators 448 and precedences of the operators. 449 TODO(dje): &^ ? */ 450 451 static const struct op_print go_op_print_tab[] = 452 { 453 {",", BINOP_COMMA, PREC_COMMA, 0}, 454 {"=", BINOP_ASSIGN, PREC_ASSIGN, 1}, 455 {"||", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0}, 456 {"&&", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0}, 457 {"|", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0}, 458 {"^", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0}, 459 {"&", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0}, 460 {"==", BINOP_EQUAL, PREC_EQUAL, 0}, 461 {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0}, 462 {"<=", BINOP_LEQ, PREC_ORDER, 0}, 463 {">=", BINOP_GEQ, PREC_ORDER, 0}, 464 {">", BINOP_GTR, PREC_ORDER, 0}, 465 {"<", BINOP_LESS, PREC_ORDER, 0}, 466 {">>", BINOP_RSH, PREC_SHIFT, 0}, 467 {"<<", BINOP_LSH, PREC_SHIFT, 0}, 468 {"+", BINOP_ADD, PREC_ADD, 0}, 469 {"-", BINOP_SUB, PREC_ADD, 0}, 470 {"*", BINOP_MUL, PREC_MUL, 0}, 471 {"/", BINOP_DIV, PREC_MUL, 0}, 472 {"%", BINOP_REM, PREC_MUL, 0}, 473 {"@", BINOP_REPEAT, PREC_REPEAT, 0}, 474 {"-", UNOP_NEG, PREC_PREFIX, 0}, 475 {"!", UNOP_LOGICAL_NOT, PREC_PREFIX, 0}, 476 {"^", UNOP_COMPLEMENT, PREC_PREFIX, 0}, 477 {"*", UNOP_IND, PREC_PREFIX, 0}, 478 {"&", UNOP_ADDR, PREC_PREFIX, 0}, 479 {"unsafe.Sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0}, 480 {"++", UNOP_POSTINCREMENT, PREC_SUFFIX, 0}, 481 {"--", UNOP_POSTDECREMENT, PREC_SUFFIX, 0}, 482 {NULL, 0, 0, 0} 483 }; 484 485 enum go_primitive_types { 486 go_primitive_type_void, 487 go_primitive_type_char, 488 go_primitive_type_bool, 489 go_primitive_type_int, 490 go_primitive_type_uint, 491 go_primitive_type_uintptr, 492 go_primitive_type_int8, 493 go_primitive_type_int16, 494 go_primitive_type_int32, 495 go_primitive_type_int64, 496 go_primitive_type_uint8, 497 go_primitive_type_uint16, 498 go_primitive_type_uint32, 499 go_primitive_type_uint64, 500 go_primitive_type_float32, 501 go_primitive_type_float64, 502 go_primitive_type_complex64, 503 go_primitive_type_complex128, 504 nr_go_primitive_types 505 }; 506 507 static void 508 go_language_arch_info (struct gdbarch *gdbarch, 509 struct language_arch_info *lai) 510 { 511 const struct builtin_go_type *builtin = builtin_go_type (gdbarch); 512 513 lai->string_char_type = builtin->builtin_char; 514 515 lai->primitive_type_vector 516 = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_go_primitive_types + 1, 517 struct type *); 518 519 lai->primitive_type_vector [go_primitive_type_void] 520 = builtin->builtin_void; 521 lai->primitive_type_vector [go_primitive_type_char] 522 = builtin->builtin_char; 523 lai->primitive_type_vector [go_primitive_type_bool] 524 = builtin->builtin_bool; 525 lai->primitive_type_vector [go_primitive_type_int] 526 = builtin->builtin_int; 527 lai->primitive_type_vector [go_primitive_type_uint] 528 = builtin->builtin_uint; 529 lai->primitive_type_vector [go_primitive_type_uintptr] 530 = builtin->builtin_uintptr; 531 lai->primitive_type_vector [go_primitive_type_int8] 532 = builtin->builtin_int8; 533 lai->primitive_type_vector [go_primitive_type_int16] 534 = builtin->builtin_int16; 535 lai->primitive_type_vector [go_primitive_type_int32] 536 = builtin->builtin_int32; 537 lai->primitive_type_vector [go_primitive_type_int64] 538 = builtin->builtin_int64; 539 lai->primitive_type_vector [go_primitive_type_uint8] 540 = builtin->builtin_uint8; 541 lai->primitive_type_vector [go_primitive_type_uint16] 542 = builtin->builtin_uint16; 543 lai->primitive_type_vector [go_primitive_type_uint32] 544 = builtin->builtin_uint32; 545 lai->primitive_type_vector [go_primitive_type_uint64] 546 = builtin->builtin_uint64; 547 lai->primitive_type_vector [go_primitive_type_float32] 548 = builtin->builtin_float32; 549 lai->primitive_type_vector [go_primitive_type_float64] 550 = builtin->builtin_float64; 551 lai->primitive_type_vector [go_primitive_type_complex64] 552 = builtin->builtin_complex64; 553 lai->primitive_type_vector [go_primitive_type_complex128] 554 = builtin->builtin_complex128; 555 556 lai->bool_type_symbol = "bool"; 557 lai->bool_type_default = builtin->builtin_bool; 558 } 559 560 static const struct language_defn go_language_defn = 561 { 562 "go", 563 language_go, 564 range_check_off, 565 case_sensitive_on, 566 array_row_major, 567 macro_expansion_no, 568 &exp_descriptor_c, 569 go_parse, 570 go_error, 571 null_post_parser, 572 c_printchar, /* Print a character constant. */ 573 c_printstr, /* Function to print string constant. */ 574 c_emit_char, /* Print a single char. */ 575 go_print_type, /* Print a type using appropriate syntax. */ 576 c_print_typedef, /* Print a typedef using appropriate 577 syntax. */ 578 go_val_print, /* Print a value using appropriate syntax. */ 579 c_value_print, /* Print a top-level value. */ 580 default_read_var_value, /* la_read_var_value */ 581 NULL, /* Language specific skip_trampoline. */ 582 NULL, /* name_of_this */ 583 basic_lookup_symbol_nonlocal, 584 basic_lookup_transparent_type, 585 go_demangle, /* Language specific symbol demangler. */ 586 NULL, /* Language specific 587 class_name_from_physname. */ 588 go_op_print_tab, /* Expression operators for printing. */ 589 1, /* C-style arrays. */ 590 0, /* String lower bound. */ 591 default_word_break_characters, 592 default_make_symbol_completion_list, 593 go_language_arch_info, 594 default_print_array_index, 595 default_pass_by_reference, 596 c_get_string, 597 NULL, 598 iterate_over_symbols, 599 LANG_MAGIC 600 }; 601 602 static void * 603 build_go_types (struct gdbarch *gdbarch) 604 { 605 struct builtin_go_type *builtin_go_type 606 = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_go_type); 607 608 builtin_go_type->builtin_void 609 = arch_type (gdbarch, TYPE_CODE_VOID, 1, "void"); 610 builtin_go_type->builtin_char 611 = arch_character_type (gdbarch, 8, 1, "char"); 612 builtin_go_type->builtin_bool 613 = arch_boolean_type (gdbarch, 8, 0, "bool"); 614 builtin_go_type->builtin_int 615 = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "int"); 616 builtin_go_type->builtin_uint 617 = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "uint"); 618 builtin_go_type->builtin_uintptr 619 = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch), 1, "uintptr"); 620 builtin_go_type->builtin_int8 621 = arch_integer_type (gdbarch, 8, 0, "int8"); 622 builtin_go_type->builtin_int16 623 = arch_integer_type (gdbarch, 16, 0, "int16"); 624 builtin_go_type->builtin_int32 625 = arch_integer_type (gdbarch, 32, 0, "int32"); 626 builtin_go_type->builtin_int64 627 = arch_integer_type (gdbarch, 64, 0, "int64"); 628 builtin_go_type->builtin_uint8 629 = arch_integer_type (gdbarch, 8, 1, "uint8"); 630 builtin_go_type->builtin_uint16 631 = arch_integer_type (gdbarch, 16, 1, "uint16"); 632 builtin_go_type->builtin_uint32 633 = arch_integer_type (gdbarch, 32, 1, "uint32"); 634 builtin_go_type->builtin_uint64 635 = arch_integer_type (gdbarch, 64, 1, "uint64"); 636 builtin_go_type->builtin_float32 637 = arch_float_type (gdbarch, 32, "float32", NULL); 638 builtin_go_type->builtin_float64 639 = arch_float_type (gdbarch, 64, "float64", NULL); 640 builtin_go_type->builtin_complex64 641 = arch_complex_type (gdbarch, "complex64", 642 builtin_go_type->builtin_float32); 643 builtin_go_type->builtin_complex128 644 = arch_complex_type (gdbarch, "complex128", 645 builtin_go_type->builtin_float64); 646 647 return builtin_go_type; 648 } 649 650 static struct gdbarch_data *go_type_data; 651 652 const struct builtin_go_type * 653 builtin_go_type (struct gdbarch *gdbarch) 654 { 655 return gdbarch_data (gdbarch, go_type_data); 656 } 657 658 extern initialize_file_ftype _initialize_go_language; 659 660 void 661 _initialize_go_language (void) 662 { 663 go_type_data = gdbarch_data_register_post_init (build_go_types); 664 665 add_language (&go_language_defn); 666 } 667