1 /* Go language support routines for GDB, the GNU debugger. 2 3 Copyright (C) 2012-2015 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_obstack.h" 36 #include "block.h" 37 #include "symtab.h" 38 #include "language.h" 39 #include "varobj.h" 40 #include "go-lang.h" 41 #include "c-lang.h" 42 #include "parser-defs.h" 43 44 #include <ctype.h> 45 46 /* The main function in the main package. */ 47 static const char GO_MAIN_MAIN[] = "main.main"; 48 49 /* Function returning the special symbol name used by Go for the main 50 procedure in the main program if it is found in minimal symbol list. 51 This function tries to find minimal symbols so that it finds them even 52 if the program was compiled without debugging information. */ 53 54 const char * 55 go_main_name (void) 56 { 57 struct bound_minimal_symbol msym; 58 59 msym = lookup_minimal_symbol (GO_MAIN_MAIN, NULL, NULL); 60 if (msym.minsym != NULL) 61 return GO_MAIN_MAIN; 62 63 /* No known entry procedure found, the main program is probably not Go. */ 64 return NULL; 65 } 66 67 /* Return non-zero if TYPE is a gccgo string. 68 We assume CHECK_TYPEDEF has already been done. */ 69 70 static int 71 gccgo_string_p (struct type *type) 72 { 73 /* gccgo strings don't necessarily have a name we can use. */ 74 75 if (TYPE_NFIELDS (type) == 2) 76 { 77 struct type *type0 = TYPE_FIELD_TYPE (type, 0); 78 struct type *type1 = TYPE_FIELD_TYPE (type, 1); 79 80 CHECK_TYPEDEF (type0); 81 CHECK_TYPEDEF (type1); 82 83 if (TYPE_CODE (type0) == TYPE_CODE_PTR 84 && strcmp (TYPE_FIELD_NAME (type, 0), "__data") == 0 85 && TYPE_CODE (type1) == TYPE_CODE_INT 86 && strcmp (TYPE_FIELD_NAME (type, 1), "__length") == 0) 87 { 88 struct type *target_type = TYPE_TARGET_TYPE (type0); 89 90 CHECK_TYPEDEF (target_type); 91 92 if (TYPE_CODE (target_type) == TYPE_CODE_INT 93 && TYPE_LENGTH (target_type) == 1 94 && strcmp (TYPE_NAME (target_type), "uint8") == 0) 95 return 1; 96 } 97 } 98 99 return 0; 100 } 101 102 /* Return non-zero if TYPE is a 6g string. 103 We assume CHECK_TYPEDEF has already been done. */ 104 105 static int 106 sixg_string_p (struct type *type) 107 { 108 if (TYPE_NFIELDS (type) == 2 109 && TYPE_TAG_NAME (type) != NULL 110 && strcmp (TYPE_TAG_NAME (type), "string") == 0) 111 return 1; 112 113 return 0; 114 } 115 116 /* Classify the kind of Go object that TYPE is. 117 TYPE is a TYPE_CODE_STRUCT, used to represent a Go object. */ 118 119 enum go_type 120 go_classify_struct_type (struct type *type) 121 { 122 CHECK_TYPEDEF (type); 123 124 /* Recognize strings as they're useful to be able to print without 125 pretty-printers. */ 126 if (gccgo_string_p (type) 127 || sixg_string_p (type)) 128 return GO_TYPE_STRING; 129 130 return GO_TYPE_NONE; 131 } 132 133 /* Subroutine of unpack_mangled_go_symbol to simplify it. 134 Given "[foo.]bar.baz", store "bar" in *PACKAGEP and "baz" in *OBJECTP. 135 We stomp on the last '.' to nul-terminate "bar". 136 The caller is responsible for memory management. */ 137 138 static void 139 unpack_package_and_object (char *buf, 140 const char **packagep, const char **objectp) 141 { 142 char *last_dot; 143 144 last_dot = strrchr (buf, '.'); 145 gdb_assert (last_dot != NULL); 146 *objectp = last_dot + 1; 147 *last_dot = '\0'; 148 last_dot = strrchr (buf, '.'); 149 if (last_dot != NULL) 150 *packagep = last_dot + 1; 151 else 152 *packagep = buf; 153 } 154 155 /* Given a mangled Go symbol, find its package name, object name, and 156 method type (if present). 157 E.g., for "libgo_net.textproto.String.N33_libgo_net.textproto.ProtocolError" 158 *PACKAGEP = "textproto" 159 *OBJECTP = "String" 160 *METHOD_TYPE_PACKAGEP = "textproto" 161 *METHOD_TYPE_OBJECTP = "ProtocolError" 162 163 Space for the resulting strings is malloc'd in one buffer. 164 PACKAGEP,OBJECTP,METHOD_TYPE* will (typically) point into this buffer. 165 [There are a few exceptions, but the caller is still responsible for 166 freeing the resulting pointer.] 167 A pointer to this buffer is returned, or NULL if symbol isn't a 168 mangled Go symbol. 169 The caller is responsible for freeing the result. 170 171 *METHOD_TYPE_IS_POINTERP is set to a boolean indicating if 172 the method type is a pointer. 173 174 There may be value in returning the outer container, 175 i.e., "net" in the above example, but for now it's not needed. 176 Plus it's currently not straightforward to compute, 177 it comes from -fgo-prefix, and there's no algorithm to compute it. 178 179 If we ever need to unpack the method type, this routine should work 180 for that too. */ 181 182 static char * 183 unpack_mangled_go_symbol (const char *mangled_name, 184 const char **packagep, 185 const char **objectp, 186 const char **method_type_packagep, 187 const char **method_type_objectp, 188 int *method_type_is_pointerp) 189 { 190 char *buf; 191 char *p; 192 int len = strlen (mangled_name); 193 /* Pointer to last digit in "N<digit(s)>_". */ 194 char *saw_digit; 195 /* Pointer to "N" if valid "N<digit(s)>_" found. */ 196 char *method_type; 197 /* Pointer to the first '.'. */ 198 char *first_dot; 199 /* Pointer to the last '.'. */ 200 char *last_dot; 201 /* Non-zero if we saw a pointer indicator. */ 202 int saw_pointer; 203 204 *packagep = *objectp = NULL; 205 *method_type_packagep = *method_type_objectp = NULL; 206 *method_type_is_pointerp = 0; 207 208 /* main.init is mangled specially. */ 209 if (strcmp (mangled_name, "__go_init_main") == 0) 210 { 211 char *package = xstrdup ("main"); 212 213 *packagep = package; 214 *objectp = "init"; 215 return package; 216 } 217 218 /* main.main is mangled specially (missing prefix). */ 219 if (strcmp (mangled_name, "main.main") == 0) 220 { 221 char *package = xstrdup ("main"); 222 223 *packagep = package; 224 *objectp = "main"; 225 return package; 226 } 227 228 /* We may get passed, e.g., "main.T.Foo", which is *not* mangled. 229 Alas it looks exactly like "prefix.package.object." 230 To cope for now we only recognize the following prefixes: 231 232 go: the default 233 libgo_.*: used by gccgo's runtime 234 235 Thus we don't support -fgo-prefix (except as used by the runtime). */ 236 if (!startswith (mangled_name, "go.") 237 && !startswith (mangled_name, "libgo_")) 238 return NULL; 239 240 /* Quick check for whether a search may be fruitful. */ 241 /* Ignore anything with @plt, etc. in it. */ 242 if (strchr (mangled_name, '@') != NULL) 243 return NULL; 244 /* It must have at least two dots. */ 245 first_dot = strchr (mangled_name, '.'); 246 if (first_dot == NULL) 247 return NULL; 248 /* Treat "foo.bar" as unmangled. It can collide with lots of other 249 languages and it's not clear what the consequences are. 250 And except for main.main, all gccgo symbols are at least 251 prefix.package.object. */ 252 last_dot = strrchr (mangled_name, '.'); 253 if (last_dot == first_dot) 254 return NULL; 255 256 /* More quick checks. */ 257 if (last_dot[1] == '\0' /* foo. */ 258 || last_dot[-1] == '.') /* foo..bar */ 259 return NULL; 260 261 /* At this point we've decided we have a mangled Go symbol. */ 262 263 buf = xstrdup (mangled_name); 264 265 /* Search backwards looking for "N<digit(s)>". */ 266 p = buf + len; 267 saw_digit = method_type = NULL; 268 saw_pointer = 0; 269 while (p > buf) 270 { 271 int current = *(const unsigned char *) --p; 272 int current_is_digit = isdigit (current); 273 274 if (saw_digit) 275 { 276 if (current_is_digit) 277 continue; 278 if (current == 'N' 279 && ((p > buf && p[-1] == '.') 280 || (p > buf + 1 && p[-1] == 'p' && p[-2] == '.'))) 281 { 282 if (atoi (p + 1) == strlen (saw_digit + 2)) 283 { 284 if (p[-1] == '.') 285 method_type = p - 1; 286 else 287 { 288 gdb_assert (p[-1] == 'p'); 289 saw_pointer = 1; 290 method_type = p - 2; 291 } 292 break; 293 } 294 } 295 /* Not what we're looking for, reset and keep looking. */ 296 saw_digit = NULL; 297 saw_pointer = 0; 298 continue; 299 } 300 if (current_is_digit && p[1] == '_') 301 { 302 /* Possible start of method "this" [sic] type. */ 303 saw_digit = p; 304 continue; 305 } 306 } 307 308 if (method_type != NULL 309 /* Ensure not something like "..foo". */ 310 && (method_type > buf && method_type[-1] != '.')) 311 { 312 unpack_package_and_object (saw_digit + 2, 313 method_type_packagep, method_type_objectp); 314 *method_type = '\0'; 315 *method_type_is_pointerp = saw_pointer; 316 } 317 318 unpack_package_and_object (buf, packagep, objectp); 319 return buf; 320 } 321 322 /* Implements the la_demangle language_defn routine for language Go. 323 324 N.B. This may get passed *any* symbol, including symbols from other 325 languages and including symbols that are already demangled. 326 Both of these situations are kinda unfortunate, but that's how things 327 are today. 328 329 N.B. This currently only supports gccgo's mangling. 330 331 N.B. gccgo's mangling needs, I think, changing. 332 This demangler can't work in all situations, 333 thus not too much effort is currently put into it. */ 334 335 char * 336 go_demangle (const char *mangled_name, int options) 337 { 338 struct obstack tempbuf; 339 char *result; 340 char *name_buf; 341 const char *package_name; 342 const char *object_name; 343 const char *method_type_package_name; 344 const char *method_type_object_name; 345 int method_type_is_pointer; 346 347 if (mangled_name == NULL) 348 return NULL; 349 350 name_buf = unpack_mangled_go_symbol (mangled_name, 351 &package_name, &object_name, 352 &method_type_package_name, 353 &method_type_object_name, 354 &method_type_is_pointer); 355 if (name_buf == NULL) 356 return NULL; 357 358 obstack_init (&tempbuf); 359 360 /* Print methods as they appear in "method expressions". */ 361 if (method_type_package_name != NULL) 362 { 363 /* FIXME: Seems like we should include package_name here somewhere. */ 364 if (method_type_is_pointer) 365 obstack_grow_str (&tempbuf, "(*"); 366 obstack_grow_str (&tempbuf, method_type_package_name); 367 obstack_grow_str (&tempbuf, "."); 368 obstack_grow_str (&tempbuf, method_type_object_name); 369 if (method_type_is_pointer) 370 obstack_grow_str (&tempbuf, ")"); 371 obstack_grow_str (&tempbuf, "."); 372 obstack_grow_str (&tempbuf, object_name); 373 } 374 else 375 { 376 obstack_grow_str (&tempbuf, package_name); 377 obstack_grow_str (&tempbuf, "."); 378 obstack_grow_str (&tempbuf, object_name); 379 } 380 obstack_grow_str0 (&tempbuf, ""); 381 382 result = xstrdup (obstack_finish (&tempbuf)); 383 obstack_free (&tempbuf, NULL); 384 xfree (name_buf); 385 return result; 386 } 387 388 /* Given a Go symbol, return its package or NULL if unknown. 389 Space for the result is malloc'd, caller must free. */ 390 391 char * 392 go_symbol_package_name (const struct symbol *sym) 393 { 394 const char *mangled_name = SYMBOL_LINKAGE_NAME (sym); 395 const char *package_name; 396 const char *object_name; 397 const char *method_type_package_name; 398 const char *method_type_object_name; 399 int method_type_is_pointer; 400 char *name_buf; 401 char *result; 402 403 gdb_assert (SYMBOL_LANGUAGE (sym) == language_go); 404 name_buf = unpack_mangled_go_symbol (mangled_name, 405 &package_name, &object_name, 406 &method_type_package_name, 407 &method_type_object_name, 408 &method_type_is_pointer); 409 /* Some Go symbols don't have mangled form we interpret (yet). */ 410 if (name_buf == NULL) 411 return NULL; 412 result = xstrdup (package_name); 413 xfree (name_buf); 414 return result; 415 } 416 417 /* Return the package that BLOCK is in, or NULL if there isn't one. 418 Space for the result is malloc'd, caller must free. */ 419 420 char * 421 go_block_package_name (const struct block *block) 422 { 423 while (block != NULL) 424 { 425 struct symbol *function = BLOCK_FUNCTION (block); 426 427 if (function != NULL) 428 { 429 char *package_name = go_symbol_package_name (function); 430 431 if (package_name != NULL) 432 return package_name; 433 434 /* Stop looking if we find a function without a package name. 435 We're most likely outside of Go and thus the concept of the 436 "current" package is gone. */ 437 return NULL; 438 } 439 440 block = BLOCK_SUPERBLOCK (block); 441 } 442 443 return NULL; 444 } 445 446 /* Table mapping opcodes into strings for printing operators 447 and precedences of the operators. 448 TODO(dje): &^ ? */ 449 450 static const struct op_print go_op_print_tab[] = 451 { 452 {",", BINOP_COMMA, PREC_COMMA, 0}, 453 {"=", BINOP_ASSIGN, PREC_ASSIGN, 1}, 454 {"||", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0}, 455 {"&&", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0}, 456 {"|", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0}, 457 {"^", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0}, 458 {"&", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0}, 459 {"==", BINOP_EQUAL, PREC_EQUAL, 0}, 460 {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0}, 461 {"<=", BINOP_LEQ, PREC_ORDER, 0}, 462 {">=", BINOP_GEQ, PREC_ORDER, 0}, 463 {">", BINOP_GTR, PREC_ORDER, 0}, 464 {"<", BINOP_LESS, PREC_ORDER, 0}, 465 {">>", BINOP_RSH, PREC_SHIFT, 0}, 466 {"<<", BINOP_LSH, PREC_SHIFT, 0}, 467 {"+", BINOP_ADD, PREC_ADD, 0}, 468 {"-", BINOP_SUB, PREC_ADD, 0}, 469 {"*", BINOP_MUL, PREC_MUL, 0}, 470 {"/", BINOP_DIV, PREC_MUL, 0}, 471 {"%", BINOP_REM, PREC_MUL, 0}, 472 {"@", BINOP_REPEAT, PREC_REPEAT, 0}, 473 {"-", UNOP_NEG, PREC_PREFIX, 0}, 474 {"!", UNOP_LOGICAL_NOT, PREC_PREFIX, 0}, 475 {"^", UNOP_COMPLEMENT, PREC_PREFIX, 0}, 476 {"*", UNOP_IND, PREC_PREFIX, 0}, 477 {"&", UNOP_ADDR, PREC_PREFIX, 0}, 478 {"unsafe.Sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0}, 479 {"++", UNOP_POSTINCREMENT, PREC_SUFFIX, 0}, 480 {"--", UNOP_POSTDECREMENT, PREC_SUFFIX, 0}, 481 {NULL, 0, 0, 0} 482 }; 483 484 enum go_primitive_types { 485 go_primitive_type_void, 486 go_primitive_type_char, 487 go_primitive_type_bool, 488 go_primitive_type_int, 489 go_primitive_type_uint, 490 go_primitive_type_uintptr, 491 go_primitive_type_int8, 492 go_primitive_type_int16, 493 go_primitive_type_int32, 494 go_primitive_type_int64, 495 go_primitive_type_uint8, 496 go_primitive_type_uint16, 497 go_primitive_type_uint32, 498 go_primitive_type_uint64, 499 go_primitive_type_float32, 500 go_primitive_type_float64, 501 go_primitive_type_complex64, 502 go_primitive_type_complex128, 503 nr_go_primitive_types 504 }; 505 506 static void 507 go_language_arch_info (struct gdbarch *gdbarch, 508 struct language_arch_info *lai) 509 { 510 const struct builtin_go_type *builtin = builtin_go_type (gdbarch); 511 512 lai->string_char_type = builtin->builtin_char; 513 514 lai->primitive_type_vector 515 = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_go_primitive_types + 1, 516 struct type *); 517 518 lai->primitive_type_vector [go_primitive_type_void] 519 = builtin->builtin_void; 520 lai->primitive_type_vector [go_primitive_type_char] 521 = builtin->builtin_char; 522 lai->primitive_type_vector [go_primitive_type_bool] 523 = builtin->builtin_bool; 524 lai->primitive_type_vector [go_primitive_type_int] 525 = builtin->builtin_int; 526 lai->primitive_type_vector [go_primitive_type_uint] 527 = builtin->builtin_uint; 528 lai->primitive_type_vector [go_primitive_type_uintptr] 529 = builtin->builtin_uintptr; 530 lai->primitive_type_vector [go_primitive_type_int8] 531 = builtin->builtin_int8; 532 lai->primitive_type_vector [go_primitive_type_int16] 533 = builtin->builtin_int16; 534 lai->primitive_type_vector [go_primitive_type_int32] 535 = builtin->builtin_int32; 536 lai->primitive_type_vector [go_primitive_type_int64] 537 = builtin->builtin_int64; 538 lai->primitive_type_vector [go_primitive_type_uint8] 539 = builtin->builtin_uint8; 540 lai->primitive_type_vector [go_primitive_type_uint16] 541 = builtin->builtin_uint16; 542 lai->primitive_type_vector [go_primitive_type_uint32] 543 = builtin->builtin_uint32; 544 lai->primitive_type_vector [go_primitive_type_uint64] 545 = builtin->builtin_uint64; 546 lai->primitive_type_vector [go_primitive_type_float32] 547 = builtin->builtin_float32; 548 lai->primitive_type_vector [go_primitive_type_float64] 549 = builtin->builtin_float64; 550 lai->primitive_type_vector [go_primitive_type_complex64] 551 = builtin->builtin_complex64; 552 lai->primitive_type_vector [go_primitive_type_complex128] 553 = builtin->builtin_complex128; 554 555 lai->bool_type_symbol = "bool"; 556 lai->bool_type_default = builtin->builtin_bool; 557 } 558 559 static const struct language_defn go_language_defn = 560 { 561 "go", 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 &default_varobj_ops, 600 NULL, 601 NULL, 602 LANG_MAGIC 603 }; 604 605 static void * 606 build_go_types (struct gdbarch *gdbarch) 607 { 608 struct builtin_go_type *builtin_go_type 609 = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_go_type); 610 611 builtin_go_type->builtin_void 612 = arch_type (gdbarch, TYPE_CODE_VOID, 1, "void"); 613 builtin_go_type->builtin_char 614 = arch_character_type (gdbarch, 8, 1, "char"); 615 builtin_go_type->builtin_bool 616 = arch_boolean_type (gdbarch, 8, 0, "bool"); 617 builtin_go_type->builtin_int 618 = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "int"); 619 builtin_go_type->builtin_uint 620 = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "uint"); 621 builtin_go_type->builtin_uintptr 622 = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch), 1, "uintptr"); 623 builtin_go_type->builtin_int8 624 = arch_integer_type (gdbarch, 8, 0, "int8"); 625 builtin_go_type->builtin_int16 626 = arch_integer_type (gdbarch, 16, 0, "int16"); 627 builtin_go_type->builtin_int32 628 = arch_integer_type (gdbarch, 32, 0, "int32"); 629 builtin_go_type->builtin_int64 630 = arch_integer_type (gdbarch, 64, 0, "int64"); 631 builtin_go_type->builtin_uint8 632 = arch_integer_type (gdbarch, 8, 1, "uint8"); 633 builtin_go_type->builtin_uint16 634 = arch_integer_type (gdbarch, 16, 1, "uint16"); 635 builtin_go_type->builtin_uint32 636 = arch_integer_type (gdbarch, 32, 1, "uint32"); 637 builtin_go_type->builtin_uint64 638 = arch_integer_type (gdbarch, 64, 1, "uint64"); 639 builtin_go_type->builtin_float32 640 = arch_float_type (gdbarch, 32, "float32", NULL); 641 builtin_go_type->builtin_float64 642 = arch_float_type (gdbarch, 64, "float64", NULL); 643 builtin_go_type->builtin_complex64 644 = arch_complex_type (gdbarch, "complex64", 645 builtin_go_type->builtin_float32); 646 builtin_go_type->builtin_complex128 647 = arch_complex_type (gdbarch, "complex128", 648 builtin_go_type->builtin_float64); 649 650 return builtin_go_type; 651 } 652 653 static struct gdbarch_data *go_type_data; 654 655 const struct builtin_go_type * 656 builtin_go_type (struct gdbarch *gdbarch) 657 { 658 return gdbarch_data (gdbarch, go_type_data); 659 } 660 661 extern initialize_file_ftype _initialize_go_language; 662 663 void 664 _initialize_go_language (void) 665 { 666 go_type_data = gdbarch_data_register_post_init (build_go_types); 667 668 add_language (&go_language_defn); 669 } 670