smatch_type.c

   1 /*
   2  * Copyright (C) 2009 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 /*
  19  * The idea here is that you have an expression and you
  20  * want to know what the type is for that.
  21  */
  22
  23 #include "smatch.h"
  24 #include "smatch_slist.h"
  25
  26 struct symbol *get_real_base_type(struct symbol *sym)
  27 {
  28         struct symbol *ret;
  29
  30         if (!sym)
  31                 return NULL;
  32         if (sym->type == SYM_BASETYPE)
  33                 return sym;
  34         ret = get_base_type(sym);
  35         if (!ret)
  36                 return NULL;
  37         if (ret->type == SYM_RESTRICT || ret->type == SYM_NODE)
  38                 return get_real_base_type(ret);
  39         return ret;
  40 }
  41
  42 int type_bytes(struct symbol *type)
  43 {
  44         int bits;
  45
  46         if (type && type->type == SYM_ARRAY)
  47                 return array_bytes(type);
  48
  49         bits = type_bits(type);
  50         if (bits < 0)
  51                 return 0;
  52         return bits_to_bytes(bits);
  53 }
  54
  55 int array_bytes(struct symbol *type)
  56 {
  57         if (!type || type->type != SYM_ARRAY)
  58                 return 0;
  59         return bits_to_bytes(type->bit_size);
  60 }
  61
  62 static struct symbol *get_binop_type(struct expression *expr)
  63 {
  64         struct symbol *left, *right;
  65
  66         left = get_type(expr->left);
  67         if (!left)
  68                 return NULL;
  69
  70         if (expr->op == SPECIAL_LEFTSHIFT ||
  71             expr->op == SPECIAL_RIGHTSHIFT) {
  72                 if (type_positive_bits(left) < 31)
  73                         return &int_ctype;
  74                 return left;
  75         }
  76         right = get_type(expr->right);
  77         if (!right)
  78                 return NULL;
  79
  80         if (expr->op == '-' &&
  81             (is_ptr_type(left) && is_ptr_type(right)))
  82                 return ssize_t_ctype;
  83
  84         if (left->type == SYM_PTR || left->type == SYM_ARRAY)
  85                 return left;
  86         if (right->type == SYM_PTR || right->type == SYM_ARRAY)
  87                 return right;
  88
  89         if (type_positive_bits(left) < 31 && type_positive_bits(right) < 31)
  90                 return &int_ctype;
  91
  92         if (type_positive_bits(left) > type_positive_bits(right))
  93                 return left;
  94         return right;
  95 }
  96
  97 static struct symbol *get_type_symbol(struct expression *expr)
  98 {
  99         if (!expr || expr->type != EXPR_SYMBOL || !expr->symbol)
 100                 return NULL;
 101
 102         return get_real_base_type(expr->symbol);
 103 }
 104
 105 static struct symbol *get_member_symbol(struct symbol_list *symbol_list, struct ident *member)
 106 {
 107         struct symbol *tmp, *sub;
 108
 109         FOR_EACH_PTR(symbol_list, tmp) {
 110                 if (!tmp->ident) {
 111                         sub = get_real_base_type(tmp);
 112                         sub = get_member_symbol(sub->symbol_list, member);
 113                         if (sub)
 114                                 return sub;
 115                         continue;
 116                 }
 117                 if (tmp->ident == member)
 118                         return tmp;
 119         } END_FOR_EACH_PTR(tmp);
 120
 121         return NULL;
 122 }
 123
 124 static struct symbol *get_symbol_from_deref(struct expression *expr)
 125 {
 126         struct ident *member;
 127         struct symbol *sym;
 128
 129         if (!expr || expr->type != EXPR_DEREF)
 130                 return NULL;
 131
 132         member = expr->member;
 133         sym = get_type(expr->deref);
 134         if (!sym) {
 135                 // sm_msg("could not find struct type");
 136                 return NULL;
 137         }
 138         if (sym->type == SYM_PTR)
 139                 sym = get_real_base_type(sym);
 140         sym = get_member_symbol(sym->symbol_list, member);
 141         if (!sym)
 142                 return NULL;
 143         return get_real_base_type(sym);
 144 }
 145
 146 static struct symbol *get_return_type(struct expression *expr)
 147 {
 148         struct symbol *tmp;
 149
 150         tmp = get_type(expr->fn);
 151         if (!tmp)
 152                 return NULL;
 153         /* this is to handle __builtin_constant_p() */
 154         if (tmp->type != SYM_FN)
 155                 tmp = get_base_type(tmp);
 156         return get_real_base_type(tmp);
 157 }
 158
 159 static struct symbol *get_expr_stmt_type(struct statement *stmt)
 160 {
 161         if (stmt->type != STMT_COMPOUND)
 162                 return NULL;
 163         stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 164         if (stmt->type == STMT_LABEL)
 165                 stmt = stmt->label_statement;
 166         if (stmt->type != STMT_EXPRESSION)
 167                 return NULL;
 168         return get_type(stmt->expression);
 169 }
 170
 171 static struct symbol *get_select_type(struct expression *expr)
 172 {
 173         struct symbol *one, *two;
 174
 175         one = get_type(expr->cond_true);
 176         two = get_type(expr->cond_false);
 177         if (!one || !two)
 178                 return NULL;
 179         /*
 180          * This is a hack.  If the types are not equiv then we
 181          * really don't know the type.  But I think guessing is
 182          *  probably Ok here.
 183          */
 184         if (type_positive_bits(one) > type_positive_bits(two))
 185                 return one;
 186         return two;
 187 }
 188
 189 struct symbol *get_pointer_type(struct expression *expr)
 190 {
 191         struct symbol *sym;
 192
 193         sym = get_type(expr);
 194         if (!sym)
 195                 return NULL;
 196         if (sym->type == SYM_NODE) {
 197                 sym = get_real_base_type(sym);
 198                 if (!sym)
 199                         return NULL;
 200         }
 201         if (sym->type != SYM_PTR && sym->type != SYM_ARRAY)
 202                 return NULL;
 203         return get_real_base_type(sym);
 204 }
 205
 206 static struct symbol *fake_pointer_sym(struct expression *expr)
 207 {
 208         struct symbol *sym;
 209         struct symbol *base;
 210
 211         sym = alloc_symbol(expr->pos, SYM_PTR);
 212         expr = expr->unop;
 213         base = get_type(expr);
 214         if (!base)
 215                 return NULL;
 216         sym->ctype.base_type = base;
 217         return sym;
 218 }
 219
 220 static struct symbol *get_type_helper(struct expression *expr)
 221 {
 222         struct symbol *ret;
 223
 224         expr = strip_parens(expr);
 225         if (!expr)
 226                 return NULL;
 227
 228         if (expr->ctype)
 229                 return expr->ctype;
 230
 231         switch (expr->type) {
 232         case EXPR_STRING:
 233                 ret = &string_ctype;
 234                 break;
 235         case EXPR_SYMBOL:
 236                 ret = get_type_symbol(expr);
 237                 break;
 238         case EXPR_DEREF:
 239                 ret = get_symbol_from_deref(expr);
 240                 break;
 241         case EXPR_PREOP:
 242         case EXPR_POSTOP:
 243                 if (expr->op == '&')
 244                         ret = fake_pointer_sym(expr);
 245                 else if (expr->op == '*')
 246                         ret = get_pointer_type(expr->unop);
 247                 else
 248                         ret = get_type(expr->unop);
 249                 break;
 250         case EXPR_ASSIGNMENT:
 251                 ret = get_type(expr->left);
 252                 break;
 253         case EXPR_CAST:
 254         case EXPR_FORCE_CAST:
 255         case EXPR_IMPLIED_CAST:
 256                 ret = get_real_base_type(expr->cast_type);
 257                 break;
 258         case EXPR_COMPARE:
 259         case EXPR_BINOP:
 260                 ret = get_binop_type(expr);
 261                 break;
 262         case EXPR_CALL:
 263                 ret = get_return_type(expr);
 264                 break;
 265         case EXPR_STATEMENT:
 266                 ret = get_expr_stmt_type(expr->statement);
 267                 break;
 268         case EXPR_CONDITIONAL:
 269         case EXPR_SELECT:
 270                 ret = get_select_type(expr);
 271                 break;
 272         case EXPR_SIZEOF:
 273                 ret = &ulong_ctype;
 274                 break;
 275         case EXPR_LOGICAL:
 276                 ret = &int_ctype;
 277                 break;
 278         default:
 279                 return NULL;
 280         }
 281
 282         if (ret && ret->type == SYM_TYPEOF)
 283                 ret = get_type(ret->initializer);
 284
 285         expr->ctype = ret;
 286         return ret;
 287 }
 288
 289 static struct symbol *get_final_type_helper(struct expression *expr)
 290 {
 291         /*
 292          * The problem is that I wrote a bunch of Smatch to think that
 293          * you could do get_type() on an expression and it would give
 294          * you what the comparison was type promoted to.  This is wrong
 295          * but fixing it is a big of work...  Hence this horrible hack.
 296          *
 297          */
 298
 299         expr = strip_parens(expr);
 300         if (!expr)
 301                 return NULL;
 302
 303         if (expr->type == EXPR_COMPARE)
 304                 return &int_ctype;
 305
 306         return NULL;
 307 }
 308
 309 struct symbol *get_type(struct expression *expr)
 310 {
 311         return get_type_helper(expr);
 312 }
 313
 314 struct symbol *get_final_type(struct expression *expr)
 315 {
 316         struct symbol *ret;
 317
 318         ret = get_final_type_helper(expr);
 319         if (ret)
 320                 return ret;
 321         return get_type_helper(expr);
 322 }
 323
 324 struct symbol *get_promoted_type(struct symbol *left, struct symbol *right)
 325 {
 326         struct symbol *ret = &int_ctype;
 327
 328         if (type_positive_bits(left) > type_positive_bits(ret))
 329                 ret = left;
 330         if (type_positive_bits(right) > type_positive_bits(ret))
 331                 ret = right;
 332
 333         if (type_is_ptr(left))
 334                 ret = left;
 335         if (type_is_ptr(right))
 336                 ret = right;
 337
 338         return ret;
 339 }
 340
 341 int type_signed(struct symbol *base_type)
 342 {
 343         if (!base_type)
 344                 return 0;
 345         if (base_type->ctype.modifiers & MOD_SIGNED)
 346                 return 1;
 347         return 0;
 348 }
 349
 350 int expr_unsigned(struct expression *expr)
 351 {
 352         struct symbol *sym;
 353
 354         sym = get_type(expr);
 355         if (!sym)
 356                 return 0;
 357         if (type_unsigned(sym))
 358                 return 1;
 359         return 0;
 360 }
 361
 362 int expr_signed(struct expression *expr)
 363 {
 364         struct symbol *sym;
 365
 366         sym = get_type(expr);
 367         if (!sym)
 368                 return 0;
 369         if (type_signed(sym))
 370                 return 1;
 371         return 0;
 372 }
 373
 374 int returns_unsigned(struct symbol *sym)
 375 {
 376         if (!sym)
 377                 return 0;
 378         sym = get_base_type(sym);
 379         if (!sym || sym->type != SYM_FN)
 380                 return 0;
 381         sym = get_base_type(sym);
 382         return type_unsigned(sym);
 383 }
 384
 385 int is_pointer(struct expression *expr)
 386 {
 387         struct symbol *sym;
 388
 389         sym = get_type(expr);
 390         if (!sym)
 391                 return 0;
 392         if (sym == &string_ctype)
 393                 return 0;
 394         if (sym->type == SYM_PTR)
 395                 return 1;
 396         return 0;
 397 }
 398
 399 int returns_pointer(struct symbol *sym)
 400 {
 401         if (!sym)
 402                 return 0;
 403         sym = get_base_type(sym);
 404         if (!sym || sym->type != SYM_FN)
 405                 return 0;
 406         sym = get_base_type(sym);
 407         if (sym->type == SYM_PTR)
 408                 return 1;
 409         return 0;
 410 }
 411
 412 sval_t sval_type_max(struct symbol *base_type)
 413 {
 414         sval_t ret;
 415
 416         if (!base_type || !type_bits(base_type))
 417                 base_type = &llong_ctype;
 418         ret.type = base_type;
 419
 420         ret.value = (~0ULL) >> (64 - type_positive_bits(base_type));
 421         return ret;
 422 }
 423
 424 sval_t sval_type_min(struct symbol *base_type)
 425 {
 426         sval_t ret;
 427
 428         if (!base_type || !type_bits(base_type))
 429                 base_type = &llong_ctype;
 430         ret.type = base_type;
 431
 432         if (type_unsigned(base_type) || is_ptr_type(base_type)) {
 433                 ret.value = 0;
 434                 return ret;
 435         }
 436
 437         ret.value = (~0ULL) << type_positive_bits(base_type);
 438
 439         return ret;
 440 }
 441
 442 int nr_bits(struct expression *expr)
 443 {
 444         struct symbol *type;
 445
 446         type = get_type(expr);
 447         if (!type)
 448                 return 0;
 449         return type_bits(type);
 450 }
 451
 452 int is_void_pointer(struct expression *expr)
 453 {
 454         struct symbol *type;
 455
 456         type = get_type(expr);
 457         if (!type || type->type != SYM_PTR)
 458                 return 0;
 459         type = get_real_base_type(type);
 460         if (type == &void_ctype)
 461                 return 1;
 462         return 0;
 463 }
 464
 465 int is_char_pointer(struct expression *expr)
 466 {
 467         struct symbol *type;
 468
 469         type = get_type(expr);
 470         if (!type || type->type != SYM_PTR)
 471                 return 0;
 472         type = get_real_base_type(type);
 473         if (type == &char_ctype)
 474                 return 1;
 475         return 0;
 476 }
 477
 478 int is_string(struct expression *expr)
 479 {
 480         expr = strip_expr(expr);
 481         if (!expr || expr->type != EXPR_STRING)
 482                 return 0;
 483         if (expr->string)
 484                 return 1;
 485         return 0;
 486 }
 487
 488 int is_static(struct expression *expr)
 489 {
 490         char *name;
 491         struct symbol *sym;
 492         int ret = 0;
 493
 494         name = expr_to_str_sym(expr, &sym);
 495         if (!name || !sym)
 496                 goto free;
 497
 498         if (sym->ctype.modifiers & MOD_STATIC)
 499                 ret = 1;
 500 free:
 501         free_string(name);
 502         return ret;
 503 }
 504
 505 int is_local_variable(struct expression *expr)
 506 {
 507         struct symbol *sym;
 508         char *name;
 509
 510         name = expr_to_var_sym(expr, &sym);
 511         free_string(name);
 512         if (!sym || !sym->scope || !sym->scope->token || !cur_func_sym)
 513                 return 0;
 514         if (cmp_pos(sym->scope->token->pos, cur_func_sym->pos) < 0)
 515                 return 0;
 516         if (is_static(expr))
 517                 return 0;
 518         return 1;
 519 }
 520
 521 int types_equiv(struct symbol *one, struct symbol *two)
 522 {
 523         if (!one && !two)
 524                 return 1;
 525         if (!one || !two)
 526                 return 0;
 527         if (one->type != two->type)
 528                 return 0;
 529         if (one->type == SYM_PTR)
 530                 return types_equiv(get_real_base_type(one), get_real_base_type(two));
 531         if (type_positive_bits(one) != type_positive_bits(two))
 532                 return 0;
 533         return 1;
 534 }
 535
 536 int fn_static(void)
 537 {
 538         return !!(cur_func_sym->ctype.modifiers & MOD_STATIC);
 539 }
 540
 541 const char *global_static(void)
 542 {
 543         if (cur_func_sym->ctype.modifiers & MOD_STATIC)
 544                 return "static";
 545         else
 546                 return "global";
 547 }
 548
 549 struct symbol *cur_func_return_type(void)
 550 {
 551         struct symbol *sym;
 552
 553         sym = get_real_base_type(cur_func_sym);
 554         if (!sym || sym->type != SYM_FN)
 555                 return NULL;
 556         sym = get_real_base_type(sym);
 557         return sym;
 558 }
 559
 560 struct symbol *get_arg_type(struct expression *fn, int arg)
 561 {
 562         struct symbol *fn_type;
 563         struct symbol *tmp;
 564         struct symbol *arg_type;
 565         int i;
 566
 567         fn_type = get_type(fn);
 568         if (!fn_type)
 569                 return NULL;
 570         if (fn_type->type == SYM_PTR)
 571                 fn_type = get_real_base_type(fn_type);
 572         if (fn_type->type != SYM_FN)
 573                 return NULL;
 574
 575         i = 0;
 576         FOR_EACH_PTR(fn_type->arguments, tmp) {
 577                 arg_type = get_real_base_type(tmp);
 578                 if (i == arg) {
 579                         return arg_type;
 580                 }
 581                 i++;
 582         } END_FOR_EACH_PTR(tmp);
 583
 584         return NULL;
 585 }
 586
 587 static struct symbol *get_member_from_string(struct symbol_list *symbol_list, const char *name)
 588 {
 589         struct symbol *tmp, *sub;
 590         int chunk_len;
 591
 592         if (strncmp(name, ".", 1) == 0)
 593                 name += 1;
 594         else if (strncmp(name, "->", 2) == 0)
 595                 name += 2;
 596
 597         FOR_EACH_PTR(symbol_list, tmp) {
 598                 if (!tmp->ident) {
 599                         sub = get_real_base_type(tmp);
 600                         sub = get_member_from_string(sub->symbol_list, name);
 601                         if (sub)
 602                                 return sub;
 603                         continue;
 604                 }
 605
 606                 if (strcmp(tmp->ident->name, name) == 0)
 607                         return tmp;
 608
 609                 chunk_len = tmp->ident->len;
 610                 if (strncmp(tmp->ident->name, name, chunk_len) == 0 &&
 611                     (name[chunk_len] == '.' || name[chunk_len] == '-')) {
 612                         sub = get_real_base_type(tmp);
 613                         if (sub->type == SYM_PTR)
 614                                 sub = get_real_base_type(sub);
 615                         return get_member_from_string(sub->symbol_list, name + chunk_len);
 616                 }
 617
 618         } END_FOR_EACH_PTR(tmp);
 619
 620         return NULL;
 621 }
 622
 623 struct symbol *get_member_type_from_key(struct expression *expr, const char *key)
 624 {
 625         struct symbol *sym;
 626
 627         if (strcmp(key, "$") == 0)
 628                 return get_type(expr);
 629
 630         if (strcmp(key, "*$") == 0) {
 631                 sym = get_type(expr);
 632                 if (!sym || sym->type != SYM_PTR)
 633                         return NULL;
 634                 return get_real_base_type(sym);
 635         }
 636
 637         sym = get_type(expr);
 638         if (!sym)
 639                 return NULL;
 640         if (sym->type == SYM_PTR)
 641                 sym = get_real_base_type(sym);
 642
 643         key = key + 1;
 644         sym = get_member_from_string(sym->symbol_list, key);
 645         if (!sym)
 646                 return NULL;
 647         return get_real_base_type(sym);
 648 }
 649
 650 struct symbol *get_arg_type_from_key(struct expression *fn, int param, struct expression *arg, const char *key)
 651 {
 652         struct symbol *type;
 653
 654         if (!key)
 655                 return NULL;
 656         if (strcmp(key, "$") == 0)
 657                 return get_arg_type(fn, param);
 658         if (strcmp(key, "*$") == 0) {
 659                 type = get_arg_type(fn, param);
 660                 if (!type || type->type != SYM_PTR)
 661                         return NULL;
 662                 return get_real_base_type(type);
 663         }
 664         return get_member_type_from_key(arg, key);
 665 }
 666
 667 int is_struct(struct expression *expr)
 668 {
 669         struct symbol *type;
 670
 671         type = get_type(expr);
 672         if (type && type->type == SYM_STRUCT)
 673                 return 1;
 674         return 0;
 675 }
 676
 677 static struct {
 678         struct symbol *sym;
 679         const char *name;
 680 } base_types[] = {
 681         {&bool_ctype, "bool"},
 682         {&void_ctype, "void"},
 683         {&type_ctype, "type"},
 684         {&char_ctype, "char"},
 685         {&schar_ctype, "schar"},
 686         {&uchar_ctype, "uchar"},
 687         {&short_ctype, "short"},
 688         {&sshort_ctype, "sshort"},
 689         {&ushort_ctype, "ushort"},
 690         {&int_ctype, "int"},
 691         {&sint_ctype, "sint"},
 692         {&uint_ctype, "uint"},
 693         {&long_ctype, "long"},
 694         {&slong_ctype, "slong"},
 695         {&ulong_ctype, "ulong"},
 696         {&llong_ctype, "llong"},
 697         {&sllong_ctype, "sllong"},
 698         {&ullong_ctype, "ullong"},
 699         {&lllong_ctype, "lllong"},
 700         {&slllong_ctype, "slllong"},
 701         {&ulllong_ctype, "ulllong"},
 702         {&float_ctype, "float"},
 703         {&double_ctype, "double"},
 704         {&ldouble_ctype, "ldouble"},
 705         {&string_ctype, "string"},
 706         {&ptr_ctype, "ptr"},
 707         {&lazy_ptr_ctype, "lazy_ptr"},
 708         {&incomplete_ctype, "incomplete"},
 709         {&label_ctype, "label"},
 710         {&bad_ctype, "bad"},
 711         {&null_ctype, "null"},
 712 };
 713
 714 static const char *base_type_str(struct symbol *sym)
 715 {
 716         int i;
 717
 718         for (i = 0; i < ARRAY_SIZE(base_types); i++) {
 719                 if (sym == base_types[i].sym)
 720                         return base_types[i].name;
 721         }
 722         return "<unknown>";
 723 }
 724
 725 static int type_str_helper(char *buf, int size, struct symbol *type)
 726 {
 727         int n;
 728
 729         if (!type)
 730                 return snprintf(buf, size, "<unknown>");
 731
 732         if (type->type == SYM_BASETYPE) {
 733                 return snprintf(buf, size, "%s", base_type_str(type));
 734         } else if (type->type == SYM_PTR) {
 735                 type = get_real_base_type(type);
 736                 n = type_str_helper(buf, size, type);
 737                 if (n > size)
 738                         return n;
 739                 return n + snprintf(buf + n, size - n, "*");
 740         } else if (type->type == SYM_ARRAY) {
 741                 type = get_real_base_type(type);
 742                 n = type_str_helper(buf, size, type);
 743                 if (n > size)
 744                         return n;
 745                 return n + snprintf(buf + n, size - n, "[]");
 746         } else if (type->type == SYM_STRUCT) {
 747                 return snprintf(buf, size, "struct %s", type->ident ? type->ident->name : "");
 748         } else if (type->type == SYM_UNION) {
 749                 if (type->ident)
 750                         return snprintf(buf, size, "union %s", type->ident->name);
 751                 else
 752                         return snprintf(buf, size, "anonymous union");
 753         } else if (type->type == SYM_FN) {
 754                 struct symbol *arg, *return_type, *arg_type;
 755                 int i;
 756
 757                 return_type = get_real_base_type(type);
 758                 n = type_str_helper(buf, size, return_type);
 759                 if (n > size)
 760                         return n;
 761                 n += snprintf(buf + n, size - n, "(*)(");
 762                 if (n > size)
 763                         return n;
 764
 765                 i = 0;
 766                 FOR_EACH_PTR(type->arguments, arg) {
 767                         if (i++)
 768                                 n += snprintf(buf + n, size - n, ", ");
 769                         if (n > size)
 770                                 return n;
 771                         arg_type = get_real_base_type(arg);
 772                         n += type_str_helper(buf + n, size - n, arg_type);
 773                         if (n > size)
 774                                 return n;
 775                 } END_FOR_EACH_PTR(arg);
 776
 777                 return n + snprintf(buf + n, size - n, ")");
 778         } else if (type->type == SYM_NODE) {
 779                 n = snprintf(buf, size, "node {");
 780                 if (n > size)
 781                         return n;
 782                 type = get_real_base_type(type);
 783                 n += type_str_helper(buf + n, size - n, type);
 784                 if (n > size)
 785                         return n;
 786                 return n + snprintf(buf + n, size - n, "}");
 787         } else {
 788                 return snprintf(buf, size, "<type %d>", type->type);
 789         }
 790 }
 791
 792 char *type_to_str(struct symbol *type)
 793 {
 794         static char buf[256];
 795
 796         buf[0] = '\0';
 797         type_str_helper(buf, sizeof(buf), type);
 798         return buf;
 799 }