smatch_flow.c

   1 /*
   2  * sparse/smatch_flow.c
   3  *
   4  * Copyright (C) 2006,2008 Dan Carpenter.
   5  *
   6  *  Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #define _GNU_SOURCE 1
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include "token.h"
  14 #include "scope.h"
  15 #include "smatch.h"
  16 #include "smatch_expression_stacks.h"
  17 #include "smatch_extra.h"
  18 #include "smatch_slist.h"
  19
  20 int final_pass;
  21 int __inline_call;
  22 struct expression  *__inline_fn;
  23
  24 static int __smatch_lineno = 0;
  25
  26 static char *base_file;
  27 static const char *filename;
  28 static char *pathname;
  29 static char *full_filename;
  30 static char *cur_func;
  31 static int loop_count;
  32 int __expr_stmt_count;
  33 static struct expression_list *switch_expr_stack = NULL;
  34 static struct expression_list *post_op_stack = NULL;
  35
  36 struct expression_list *big_expression_stack;
  37 struct statement_list *big_statement_stack;
  38 int __in_pre_condition = 0;
  39 int __bail_on_rest_of_function = 0;
  40 char *get_function(void) { return cur_func; }
  41 int get_lineno(void) { return __smatch_lineno; }
  42 int inside_loop(void) { return !!loop_count; }
  43 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
  44 int in_expression_statement(void) { return !!__expr_stmt_count; }
  45
  46 static void split_symlist(struct symbol_list *sym_list);
  47 static void split_declaration(struct symbol_list *sym_list);
  48 static void split_expr_list(struct expression_list *expr_list);
  49 static void add_inline_function(struct symbol *sym);
  50 static void parse_inline(struct expression *expr);
  51
  52 int option_assume_loops = 0;
  53 int option_known_conditions = 0;
  54 int option_two_passes = 0;
  55 struct symbol *cur_func_sym = NULL;
  56
  57 int outside_of_function(void)
  58 {
  59         return cur_func_sym == NULL;
  60 }
  61
  62 const char *get_filename(void)
  63 {
  64         if (option_info)
  65                 return base_file;
  66         if (option_full_path)
  67                 return full_filename;
  68         return filename;
  69 }
  70
  71 const char *get_base_file(void)
  72 {
  73         return base_file;
  74 }
  75
  76 static void set_position(struct position pos)
  77 {
  78         int len;
  79         static int prev_stream = -1;
  80
  81         if (pos.stream == 0 && pos.line == 0)
  82                 return;
  83
  84         __smatch_lineno = pos.line;
  85
  86         if (pos.stream == prev_stream)
  87                 return;
  88
  89         filename = stream_name(pos.stream);
  90
  91         free(full_filename);
  92         pathname = getcwd(NULL, 0);
  93         if (pathname) {
  94                 len = strlen(pathname) + 1 + strlen(filename) + 1;
  95                 full_filename = malloc(len);
  96                 snprintf(full_filename, len, "%s/%s", pathname, filename);
  97         } else {
  98                 full_filename = alloc_string(filename);
  99         }
 100         free(pathname);
 101 }
 102
 103 static int is_inline_func(struct expression *expr)
 104 {
 105         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 106                 return 0;
 107         if (expr->symbol->ctype.modifiers & MOD_INLINE)
 108                 return 1;
 109         return 0;
 110 }
 111
 112 static int is_noreturn_func(struct expression *expr)
 113 {
 114         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 115                 return 0;
 116         if (expr->symbol->ctype.modifiers & MOD_NORETURN)
 117                 return 1;
 118         return 0;
 119 }
 120
 121 int inlinable(struct expression *expr)
 122 {
 123         struct symbol *sym;
 124
 125         if (__inline_fn)  /* don't nest */
 126                 return 0;
 127
 128         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 129                 return 0;
 130         sym = get_base_type(expr->symbol);
 131         if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
 132                 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
 133                         return 1;
 134                 return 0;
 135         }
 136         if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
 137                 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
 138                         return 1;
 139                 return 0;
 140         }
 141         return 0;
 142 }
 143
 144 void __process_post_op_stack(void)
 145 {
 146         struct expression *expr;
 147
 148         FOR_EACH_PTR(post_op_stack, expr) {
 149                 __pass_to_client(expr, OP_HOOK);
 150         } END_FOR_EACH_PTR(expr);
 151
 152         __free_ptr_list((struct ptr_list **)&post_op_stack);
 153 }
 154
 155 void __split_expr(struct expression *expr)
 156 {
 157         if (!expr)
 158                 return;
 159
 160         // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
 161
 162         push_expression(&big_expression_stack, expr);
 163         set_position(expr->pos);
 164         __pass_to_client(expr, EXPR_HOOK);
 165
 166         switch (expr->type) {
 167         case EXPR_PREOP:
 168                 if (expr->op == '*')
 169                         __pass_to_client(expr, DEREF_HOOK);
 170                 __split_expr(expr->unop);
 171                 __pass_to_client(expr, OP_HOOK);
 172                 break;
 173         case EXPR_POSTOP:
 174                 __split_expr(expr->unop);
 175                 push_expression(&post_op_stack, expr);
 176                 break;
 177         case EXPR_STATEMENT:
 178                 __expr_stmt_count++;
 179                 __split_stmt(expr->statement);
 180                 __expr_stmt_count--;
 181                 break;
 182         case EXPR_LOGICAL:
 183         case EXPR_COMPARE:
 184                 __pass_to_client(expr, LOGIC_HOOK);
 185                 __handle_logic(expr);
 186                 break;
 187         case EXPR_BINOP:
 188                 __pass_to_client(expr, BINOP_HOOK);
 189         case EXPR_COMMA:
 190                 __split_expr(expr->left);
 191                 __process_post_op_stack();
 192                 __split_expr(expr->right);
 193                 break;
 194         case EXPR_ASSIGNMENT: {
 195                 struct expression *tmp;
 196
 197                 if (!expr->right)
 198                         break;
 199
 200                 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
 201
 202                 /* foo = !bar() */
 203                 if (__handle_condition_assigns(expr))
 204                         break;
 205                 /* foo = (x < 5 ? foo : 5); */
 206                 if (__handle_select_assigns(expr))
 207                         break;
 208                 /* foo = ({frob(); frob(); frob(); 1;}) */
 209                 if (__handle_expr_statement_assigns(expr))
 210                         break;
 211
 212                 __split_expr(expr->right);
 213                 if (outside_of_function())
 214                         __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
 215                 else
 216                         __pass_to_client(expr, ASSIGNMENT_HOOK);
 217                 tmp = strip_expr(expr->right);
 218                 if (tmp->type == EXPR_CALL)
 219                         __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
 220                 if (get_macro_name(tmp->pos) &&
 221                     get_macro_name(expr->pos) != get_macro_name(tmp->pos))
 222                         __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
 223                 __split_expr(expr->left);
 224                 break;
 225         }
 226         case EXPR_DEREF:
 227                 __pass_to_client(expr, DEREF_HOOK);
 228                 __split_expr(expr->deref);
 229                 break;
 230         case EXPR_SLICE:
 231                 __split_expr(expr->base);
 232                 break;
 233         case EXPR_CAST:
 234         case EXPR_FORCE_CAST:
 235                 __pass_to_client(expr, CAST_HOOK);
 236                 __split_expr(expr->cast_expression);
 237                 break;
 238         case EXPR_SIZEOF:
 239                 if (expr->cast_expression)
 240                         __pass_to_client(strip_parens(expr->cast_expression),
 241                                          SIZEOF_HOOK);
 242                 break;
 243         case EXPR_OFFSETOF:
 244         case EXPR_ALIGNOF:
 245                 evaluate_expression(expr);
 246                 break;
 247         case EXPR_CONDITIONAL:
 248         case EXPR_SELECT:
 249                 if (known_condition_true(expr->conditional)) {
 250                         __split_expr(expr->cond_true);
 251                         break;
 252                 }
 253                 if (known_condition_false(expr->conditional)) {
 254                         __split_expr(expr->cond_false);
 255                         break;
 256                 }
 257                 __pass_to_client(expr, SELECT_HOOK);
 258                 __split_whole_condition(expr->conditional);
 259                 __split_expr(expr->cond_true);
 260                 __push_true_states();
 261                 __use_false_states();
 262                 __split_expr(expr->cond_false);
 263                 __merge_true_states();
 264                 break;
 265         case EXPR_CALL:
 266                 if (sym_name_is("__builtin_constant_p", expr->fn))
 267                         break;
 268                 split_expr_list(expr->args);
 269                 __split_expr(expr->fn);
 270                 if (is_inline_func(expr->fn))
 271                         add_inline_function(expr->fn->symbol);
 272                 if (inlinable(expr->fn))
 273                         __inline_call = 1;
 274                 __process_post_op_stack();
 275                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 276                 __inline_call = 0;
 277                 if (inlinable(expr->fn)) {
 278                         parse_inline(expr);
 279                 }
 280                 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
 281                 if (is_noreturn_func(expr->fn))
 282                         nullify_path();
 283                 break;
 284         case EXPR_INITIALIZER:
 285                 split_expr_list(expr->expr_list);
 286                 break;
 287         case EXPR_IDENTIFIER:
 288                 __split_expr(expr->ident_expression);
 289                 break;
 290         case EXPR_INDEX:
 291                 __split_expr(expr->idx_expression);
 292                 break;
 293         case EXPR_POS:
 294                 __split_expr(expr->init_expr);
 295                 break;
 296         case EXPR_SYMBOL:
 297                 __pass_to_client(expr, SYM_HOOK);
 298                 break;
 299         case EXPR_STRING:
 300                 __pass_to_client(expr, STRING_HOOK);
 301                 break;
 302         default:
 303                 break;
 304         };
 305         pop_expression(&big_expression_stack);
 306 }
 307
 308 static int is_forever_loop(struct statement *stmt)
 309 {
 310         struct expression *expr;
 311
 312         expr = strip_expr(stmt->iterator_pre_condition);
 313         if (!expr)
 314                 expr = stmt->iterator_post_condition;
 315         if (!expr) {
 316                 /* this is a for(;;) loop... */
 317                 return 1;
 318         }
 319
 320         if (expr->type == EXPR_VALUE && expr->value == 1)
 321                 return 1;
 322
 323         return 0;
 324 }
 325
 326 static int loop_num;
 327 static char *get_loop_name(int num)
 328 {
 329         char buf[256];
 330
 331         snprintf(buf, 255, "-loop%d", num);
 332         buf[255] = '\0';
 333         return alloc_sname(buf);
 334 }
 335
 336 /*
 337  * Pre Loops are while and for loops.
 338  */
 339 static void handle_pre_loop(struct statement *stmt)
 340 {
 341         int once_through; /* we go through the loop at least once */
 342         struct sm_state *extra_sm = NULL;
 343         int unchanged = 0;
 344         char *loop_name;
 345         struct state_list *slist = NULL;
 346         struct sm_state *sm = NULL;
 347
 348         loop_name = get_loop_name(loop_num);
 349         loop_num++;
 350
 351         __split_stmt(stmt->iterator_pre_statement);
 352
 353         once_through = implied_condition_true(stmt->iterator_pre_condition);
 354
 355         loop_count++;
 356         __push_continues();
 357         __push_breaks();
 358
 359         __merge_gotos(loop_name);
 360
 361         extra_sm = __extra_handle_canonical_loops(stmt, &slist);
 362         __in_pre_condition++;
 363         __pass_to_client(stmt, PRELOOP_HOOK);
 364         __split_whole_condition(stmt->iterator_pre_condition);
 365         __in_pre_condition--;
 366         FOR_EACH_PTR(slist, sm) {
 367                 set_state(sm->owner, sm->name, sm->sym, sm->state);
 368         } END_FOR_EACH_PTR(sm);
 369         free_slist(&slist);
 370         if (extra_sm)
 371                 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
 372
 373         if (option_assume_loops)
 374                 once_through = 1;
 375
 376         __split_stmt(stmt->iterator_statement);
 377         __warn_on_silly_pre_loops();
 378         if (is_forever_loop(stmt)) {
 379                 struct state_list *slist;
 380
 381                 __save_gotos(loop_name);
 382
 383                 __push_fake_cur_slist();
 384                 __split_stmt(stmt->iterator_post_statement);
 385                 slist = __pop_fake_cur_slist();
 386
 387                 __discard_continues();
 388                 __discard_false_states();
 389                 __use_breaks();
 390
 391                 if (!__path_is_null())
 392                         __merge_slist_into_cur(slist);
 393                 free_slist(&slist);
 394         } else {
 395                 __merge_continues();
 396                 unchanged = __iterator_unchanged(extra_sm);
 397                 __split_stmt(stmt->iterator_post_statement);
 398                 __save_gotos(loop_name);
 399                 __split_whole_condition(stmt->iterator_pre_condition);
 400                 nullify_path();
 401                 __merge_false_states();
 402                 if (once_through)
 403                         __discard_false_states();
 404                 else
 405                         __merge_false_states();
 406
 407                 if (extra_sm && unchanged)
 408                         __extra_pre_loop_hook_after(extra_sm,
 409                                                 stmt->iterator_post_statement,
 410                                                 stmt->iterator_pre_condition);
 411                 __merge_breaks();
 412         }
 413         loop_count--;
 414 }
 415
 416 /*
 417  * Post loops are do {} while();
 418  */
 419 static void handle_post_loop(struct statement *stmt)
 420 {
 421         char *loop_name;
 422
 423         loop_name = get_loop_name(loop_num);
 424         loop_num++;
 425         loop_count++;
 426
 427         __push_continues();
 428         __push_breaks();
 429         __merge_gotos(loop_name);
 430         __split_stmt(stmt->iterator_statement);
 431         __merge_continues();
 432         if (!is_zero(stmt->iterator_post_condition))
 433                 __save_gotos(loop_name);
 434
 435         if (is_forever_loop(stmt)) {
 436                 __use_breaks();
 437         } else {
 438                 __split_whole_condition(stmt->iterator_post_condition);
 439                 __use_false_states();
 440                 __merge_breaks();
 441         }
 442         loop_count--;
 443 }
 444
 445 static int empty_statement(struct statement *stmt)
 446 {
 447         if (!stmt)
 448                 return 0;
 449         if (stmt->type == STMT_EXPRESSION && !stmt->expression)
 450                 return 1;
 451         return 0;
 452 }
 453
 454 static int last_stmt_on_same_line()
 455 {
 456         struct statement *stmt;
 457         int i = 0;
 458
 459         FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
 460                 if (!i++)
 461                         continue;
 462                 if  (stmt->pos.line == get_lineno())
 463                         return 1;
 464                 return 0;
 465         } END_FOR_EACH_PTR_REVERSE(stmt);
 466         return 0;
 467 }
 468
 469 static struct statement *last_stmt;
 470 static int is_last_stmt(struct statement *stmt)
 471 {
 472         if (stmt == last_stmt)
 473                 return 1;
 474         return 0;
 475 }
 476
 477 static void print_unreached_initializers(struct symbol_list *sym_list)
 478 {
 479         struct symbol *sym;
 480
 481         FOR_EACH_PTR(sym_list, sym) {
 482                 if (sym->initializer)
 483                         sm_msg("info: '%s' is not actually initialized (unreached code).",
 484                                 (sym->ident ? sym->ident->name : "this variable"));
 485         } END_FOR_EACH_PTR(sym);
 486 }
 487
 488 static void print_unreached(struct statement *stmt)
 489 {
 490         static int print = 1;
 491
 492         if (__inline_fn)
 493                 return;
 494
 495         if (!__path_is_null()) {
 496                 print = 1;
 497                 return;
 498         }
 499         if (!print)
 500                 return;
 501
 502         switch (stmt->type) {
 503         case STMT_COMPOUND: /* after a switch before a case stmt */
 504         case STMT_RANGE:
 505         case STMT_CASE:
 506         case STMT_LABEL:
 507                 return;
 508         case STMT_DECLARATION: /* switch (x) { int a; case foo: ... */
 509                 print_unreached_initializers(stmt->declaration);
 510                 return;
 511         case STMT_RETURN: /* gcc complains if you don't have a return statement */
 512                 if (is_last_stmt(stmt))
 513                         return;
 514                 break;
 515         case STMT_GOTO:
 516                 if (!option_spammy)
 517                         return;
 518                 break;
 519         default:
 520                 break;
 521         }
 522         if (!option_spammy && empty_statement(stmt))
 523                 return;
 524         sm_msg("info: ignoring unreachable code.");
 525         print = 0;
 526 }
 527
 528 static void split_asm_constraints(struct expression_list *expr_list)
 529 {
 530         struct expression *expr;
 531         int state = 0;
 532
 533         FOR_EACH_PTR(expr_list, expr) {
 534                 switch (state) {
 535                 case 0: /* identifier */
 536                 case 1: /* constraint */
 537                         state++;
 538                         continue;
 539                 case 2: /* expression */
 540                         state = 0;
 541                         __split_expr(expr);
 542                         continue;
 543                 }
 544         } END_FOR_EACH_PTR(expr);
 545 }
 546
 547 static int is_case_val(struct statement *stmt, sval_t sval)
 548 {
 549         sval_t case_sval;
 550
 551         if (stmt->type != STMT_CASE)
 552                 return 0;
 553         if (!stmt->case_expression) {
 554                 __set_default();
 555                 return 1;
 556         }
 557         if (!get_value(stmt->case_expression, &case_sval))
 558                 return 0;
 559         if (case_sval.value == sval.value)
 560                 return 1;
 561         return 0;
 562 }
 563
 564 static void split_known_switch(struct statement *stmt, sval_t sval)
 565 {
 566         struct statement *tmp;
 567
 568         __split_expr(stmt->switch_expression);
 569
 570         push_expression(&switch_expr_stack, stmt->switch_expression);
 571         __save_switch_states(top_expression(switch_expr_stack));
 572         nullify_path();
 573         __push_default();
 574         __push_breaks();
 575
 576         stmt = stmt->switch_statement;
 577
 578         if (!last_stmt)
 579                 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 580
 581         __push_scope_hooks();
 582         FOR_EACH_PTR(stmt->stmts, tmp) {
 583                 __smatch_lineno = tmp->pos.line;
 584                 if (is_case_val(tmp, sval)) {
 585                         __merge_switches(top_expression(switch_expr_stack),
 586                                          stmt->case_expression);
 587                         __pass_case_to_client(top_expression(switch_expr_stack),
 588                                               stmt->case_expression);
 589                 }
 590                 if (__path_is_null())
 591                         continue;
 592                 __split_stmt(tmp);
 593                 if (__path_is_null()) {
 594                         __set_default();
 595                         goto out;
 596                 }
 597         } END_FOR_EACH_PTR(tmp);
 598 out:
 599         __call_scope_hooks();
 600         if (!__pop_default())
 601                 __merge_switches(top_expression(switch_expr_stack),
 602                                  NULL);
 603         __discard_switches();
 604         __merge_breaks();
 605         pop_expression(&switch_expr_stack);
 606 }
 607
 608 void __split_stmt(struct statement *stmt)
 609 {
 610         sval_t sval;
 611
 612         if (!stmt)
 613                 goto out;
 614
 615         if (out_of_memory() || __bail_on_rest_of_function) {
 616                 static char *printed = NULL;
 617
 618                 if (printed != cur_func)
 619                         sm_msg("Function too hairy.  Giving up.");
 620                 final_pass = 0;  /* turn off sm_msg() from here */
 621                 printed = cur_func;
 622                 return;
 623         }
 624
 625         add_ptr_list(&big_statement_stack, stmt);
 626         free_expression_stack(&big_expression_stack);
 627         set_position(stmt->pos);
 628         print_unreached(stmt);
 629         __pass_to_client(stmt, STMT_HOOK);
 630
 631         switch (stmt->type) {
 632         case STMT_DECLARATION:
 633                 split_declaration(stmt->declaration);
 634                 break;
 635         case STMT_RETURN:
 636                 __split_expr(stmt->ret_value);
 637                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 638                 nullify_path();
 639                 break;
 640         case STMT_EXPRESSION:
 641                 __split_expr(stmt->expression);
 642                 break;
 643         case STMT_COMPOUND: {
 644                 struct statement *tmp;
 645
 646                 if (!last_stmt)
 647                         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 648                 __push_scope_hooks();
 649                 FOR_EACH_PTR(stmt->stmts, tmp) {
 650                         __split_stmt(tmp);
 651                 } END_FOR_EACH_PTR(tmp);
 652                 __call_scope_hooks();
 653                 break;
 654         }
 655         case STMT_IF:
 656                 if (known_condition_true(stmt->if_conditional)) {
 657                         __split_stmt(stmt->if_true);
 658                         break;
 659                 }
 660                 if (known_condition_false(stmt->if_conditional)) {
 661                         __split_stmt(stmt->if_false);
 662                         break;
 663                 }
 664                 if (option_known_conditions &&
 665                     implied_condition_true(stmt->if_conditional)) {
 666                         sm_info("this condition is true.");
 667                         __split_stmt(stmt->if_true);
 668                         break;
 669                 }
 670                 if (option_known_conditions &&
 671                     implied_condition_false(stmt->if_conditional)) {
 672                         sm_info("this condition is false.");
 673                         __split_stmt(stmt->if_false);
 674                         break;
 675                 }
 676                 __split_whole_condition(stmt->if_conditional);
 677                 __split_stmt(stmt->if_true);
 678                 if (empty_statement(stmt->if_true) &&
 679                         last_stmt_on_same_line() &&
 680                         !get_macro_name(stmt->if_true->pos))
 681                         sm_msg("warn: if();");
 682                 __push_true_states();
 683                 __use_false_states();
 684                 __split_stmt(stmt->if_false);
 685                 __merge_true_states();
 686                 break;
 687         case STMT_ITERATOR:
 688                 if (stmt->iterator_pre_condition)
 689                         handle_pre_loop(stmt);
 690                 else if (stmt->iterator_post_condition)
 691                         handle_post_loop(stmt);
 692                 else {
 693                         // these are for(;;) type loops.
 694                         handle_pre_loop(stmt);
 695                 }
 696                 break;
 697         case STMT_SWITCH:
 698                 if (get_value(stmt->switch_expression, &sval)) {
 699                         split_known_switch(stmt, sval);
 700                         break;
 701                 }
 702                 __split_expr(stmt->switch_expression);
 703                 push_expression(&switch_expr_stack, stmt->switch_expression);
 704                 __save_switch_states(top_expression(switch_expr_stack));
 705                 nullify_path();
 706                 __push_default();
 707                 __push_breaks();
 708                 __split_stmt(stmt->switch_statement);
 709                 if (!__pop_default())
 710                         __merge_switches(top_expression(switch_expr_stack),
 711                                       NULL);
 712                 __discard_switches();
 713                 __merge_breaks();
 714                 pop_expression(&switch_expr_stack);
 715                 break;
 716         case STMT_CASE:
 717                 __merge_switches(top_expression(switch_expr_stack),
 718                                       stmt->case_expression);
 719                 __pass_case_to_client(top_expression(switch_expr_stack),
 720                                       stmt->case_expression);
 721                 if (!stmt->case_expression)
 722                         __set_default();
 723                 __split_expr(stmt->case_expression);
 724                 __split_expr(stmt->case_to);
 725                 __split_stmt(stmt->case_statement);
 726                 break;
 727         case STMT_LABEL:
 728                 if (stmt->label_identifier &&
 729                     stmt->label_identifier->type == SYM_LABEL &&
 730                     stmt->label_identifier->ident) {
 731                         loop_count = 1000000;
 732                         __merge_gotos(stmt->label_identifier->ident->name);
 733                 }
 734                 __split_stmt(stmt->label_statement);
 735                 break;
 736         case STMT_GOTO:
 737                 __split_expr(stmt->goto_expression);
 738                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 739                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 740                                 __process_breaks();
 741                         } else if (!strcmp(stmt->goto_label->ident->name,
 742                                            "continue")) {
 743                                 __process_continues();
 744                         }
 745                 } else if (stmt->goto_label &&
 746                            stmt->goto_label->type == SYM_LABEL &&
 747                            stmt->goto_label->ident) {
 748                         __save_gotos(stmt->goto_label->ident->name);
 749                 }
 750                 nullify_path();
 751                 break;
 752         case STMT_NONE:
 753                 break;
 754         case STMT_ASM:
 755                 __pass_to_client(stmt, ASM_HOOK);
 756                 __split_expr(stmt->asm_string);
 757                 split_asm_constraints(stmt->asm_outputs);
 758                 split_asm_constraints(stmt->asm_inputs);
 759                 split_asm_constraints(stmt->asm_clobbers);
 760                 break;
 761         case STMT_CONTEXT:
 762                 break;
 763         case STMT_RANGE:
 764                 __split_expr(stmt->range_expression);
 765                 __split_expr(stmt->range_low);
 766                 __split_expr(stmt->range_high);
 767                 break;
 768         }
 769 out:
 770         __process_post_op_stack();
 771 }
 772
 773 static void split_expr_list(struct expression_list *expr_list)
 774 {
 775         struct expression *expr;
 776
 777         FOR_EACH_PTR(expr_list, expr) {
 778                 __split_expr(expr);
 779                 __process_post_op_stack();
 780         } END_FOR_EACH_PTR(expr);
 781 }
 782
 783 static void split_sym(struct symbol *sym)
 784 {
 785         if (!sym)
 786                 return;
 787         if (!(sym->namespace & NS_SYMBOL))
 788                 return;
 789
 790         __split_stmt(sym->stmt);
 791         __split_expr(sym->array_size);
 792         split_symlist(sym->arguments);
 793         split_symlist(sym->symbol_list);
 794         __split_stmt(sym->inline_stmt);
 795         split_symlist(sym->inline_symbol_list);
 796 }
 797
 798 static void split_symlist(struct symbol_list *sym_list)
 799 {
 800         struct symbol *sym;
 801
 802         FOR_EACH_PTR(sym_list, sym) {
 803                 split_sym(sym);
 804         } END_FOR_EACH_PTR(sym);
 805 }
 806
 807 typedef void (fake_cb)(struct expression *expr);
 808
 809 static int member_to_number(struct expression *expr, struct ident *member)
 810 {
 811         struct symbol *type, *tmp;
 812         char *name;
 813         int i;
 814
 815         if (!member)
 816                 return -1;
 817         name = member->name;
 818
 819         type = get_type(expr);
 820         if (!type || type->type != SYM_STRUCT)
 821                 return -1;
 822
 823         i = -1;
 824         FOR_EACH_PTR(type->symbol_list, tmp) {
 825                 i++;
 826                 if (!tmp->ident)
 827                         continue;
 828                 if (strcmp(name, tmp->ident->name) == 0)
 829                         return i;
 830         } END_FOR_EACH_PTR(tmp);
 831         return -1;
 832 }
 833
 834 static struct ident *number_to_member(struct expression *expr, int num)
 835 {
 836         struct symbol *type, *member;
 837         int i = 0;
 838
 839         type = get_type(expr);
 840         if (!type || type->type != SYM_STRUCT)
 841                 return NULL;
 842
 843         FOR_EACH_PTR(type->symbol_list, member) {
 844                 if (i == num)
 845                         return member->ident;
 846                 i++;
 847         } END_FOR_EACH_PTR(member);
 848         return NULL;
 849 }
 850
 851 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 852
 853 static void set_members_to_zero(struct expression *symbol)
 854 {
 855         struct expression *deref, *assign;
 856         struct symbol *type;
 857         struct symbol *member, *member_type;
 858
 859         type = get_type(symbol);
 860         if (!type)
 861                 return;
 862
 863         FOR_EACH_PTR(type->symbol_list, member) {
 864                 if (!member->ident)
 865                         continue;
 866                 member_type = get_real_base_type(member);
 867                 if (!member_type || member_type->type == SYM_ARRAY)
 868                         continue;
 869                 deref = member_expression(symbol, '.', member->ident);
 870                 assign = assign_expression(deref, zero_expr());
 871                 __split_expr(assign);
 872         } END_FOR_EACH_PTR(member);
 873
 874 }
 875
 876 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 877 {
 878         struct expression *deref, *assign, *tmp;
 879         struct symbol *type;
 880         struct ident *member;
 881         int member_idx = 0;
 882
 883         type = get_type(symbol);
 884         if (!type || (type->type != SYM_STRUCT && type->type != SYM_UNION))
 885                 return;
 886
 887         set_members_to_zero(symbol);
 888
 889         FOR_EACH_PTR(members, tmp) {
 890                 member = number_to_member(symbol, member_idx);
 891                 while (tmp->type == EXPR_IDENTIFIER) {
 892                         member = tmp->expr_ident;
 893                         member_idx = member_to_number(symbol, member);
 894                         tmp = tmp->ident_expression;
 895                 }
 896                 member_idx++;
 897                 deref = member_expression(symbol, '.', member);
 898                 if (tmp->type == EXPR_INITIALIZER) {
 899                         type = get_type(deref);
 900                         if (type && type->type == SYM_ARRAY)
 901                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 902                         else
 903                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 904                 } else {
 905                         assign = assign_expression(deref, tmp);
 906                         fake_cb(assign);
 907                 }
 908         } END_FOR_EACH_PTR(tmp);
 909 }
 910
 911 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
 912 {
 913         fake_member_assigns_helper(symbol_expression(sym),
 914                                    sym->initializer->expr_list, fake_cb);
 915 }
 916
 917 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
 918 {
 919         struct expression *offset, *binop, *assign, *tmp;
 920         struct symbol *type;
 921         int idx;
 922
 923         idx = 0;
 924         FOR_EACH_PTR(expr_list, tmp) {
 925                 if (tmp->type == EXPR_INDEX) {
 926                         if (tmp->idx_from != tmp->idx_to)
 927                                 return;
 928                         idx = tmp->idx_from;
 929                         if (!tmp->idx_expression)
 930                                 goto next;
 931                         tmp = tmp->idx_expression;
 932                 }
 933                 offset = value_expr(idx);
 934                 binop = array_element_expression(array, offset);
 935                 if (tmp->type == EXPR_INITIALIZER) {
 936                         type = get_type(binop);
 937                         if (type && type->type == SYM_ARRAY)
 938                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
 939                         else
 940                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
 941                 } else {
 942                         assign = assign_expression(binop, tmp);
 943                         fake_cb(assign);
 944                 }
 945 next:
 946                 idx++;
 947         } END_FOR_EACH_PTR(tmp);
 948 }
 949
 950 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
 951 {
 952         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
 953 }
 954
 955 static void fake_assign_expr(struct symbol *sym)
 956 {
 957         struct expression *assign, *symbol;
 958
 959         symbol = symbol_expression(sym);
 960         assign = assign_expression(symbol, sym->initializer);
 961         __split_expr(assign);
 962 }
 963
 964 static void call_split_expr(struct expression *expr)
 965 {
 966         __split_expr(expr);
 967 }
 968
 969 static void do_initializer_stuff(struct symbol *sym)
 970 {
 971         if (!sym->initializer)
 972                 return;
 973
 974         if (sym->initializer->type == EXPR_INITIALIZER) {
 975                 if (get_real_base_type(sym)->type == SYM_ARRAY)
 976                         fake_element_assigns(sym, call_split_expr);
 977                 else
 978                         fake_member_assigns(sym, call_split_expr);
 979         } else {
 980                 fake_assign_expr(sym);
 981         }
 982 }
 983
 984 static void split_declaration(struct symbol_list *sym_list)
 985 {
 986         struct symbol *sym;
 987
 988         FOR_EACH_PTR(sym_list, sym) {
 989                 __pass_to_client(sym, DECLARATION_HOOK);
 990                 do_initializer_stuff(sym);
 991                 split_sym(sym);
 992         } END_FOR_EACH_PTR(sym);
 993 }
 994
 995 static void call_global_assign_hooks(struct expression *assign)
 996 {
 997         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
 998 }
 999
1000 static void fake_global_assign(struct symbol *sym)
1001 {
1002         struct expression *assign, *symbol;
1003
1004         if (!sym->initializer)
1005                 return;
1006         if (sym->initializer->type == EXPR_INITIALIZER) {
1007                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1008                         fake_element_assigns(sym, call_global_assign_hooks);
1009                 else
1010                         fake_member_assigns(sym, call_global_assign_hooks);
1011         } else {
1012                 symbol = symbol_expression(sym);
1013                 assign = assign_expression(symbol, sym->initializer);
1014                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1015         }
1016 }
1017
1018 static void split_function(struct symbol *sym)
1019 {
1020         struct symbol *base_type = get_base_type(sym);
1021
1022         cur_func_sym = sym;
1023         if (sym->ident)
1024                 cur_func = sym->ident->name;
1025         __smatch_lineno = sym->pos.line;
1026         last_stmt = NULL;
1027         loop_count = 0;
1028         sm_debug("new function:  %s\n", cur_func);
1029         __slist_id = 0;
1030         if (option_two_passes) {
1031                 __unnullify_path();
1032                 loop_num = 0;
1033                 final_pass = 0;
1034                 __pass_to_client(sym, FUNC_DEF_HOOK);
1035                 __pass_to_client(sym, AFTER_DEF_HOOK);
1036                 __split_stmt(base_type->stmt);
1037                 __split_stmt(base_type->inline_stmt);
1038                 nullify_path();
1039         }
1040         __unnullify_path();
1041         loop_num = 0;
1042         final_pass = 1;
1043         __pass_to_client(sym, FUNC_DEF_HOOK);
1044         __pass_to_client(sym, AFTER_DEF_HOOK);
1045         __split_stmt(base_type->stmt);
1046         __split_stmt(base_type->inline_stmt);
1047         __pass_to_client(sym, END_FUNC_HOOK);
1048         __pass_to_client(sym, AFTER_FUNC_HOOK);
1049         cur_func_sym = NULL;
1050         cur_func = NULL;
1051         clear_all_states();
1052         free_data_info_allocs();
1053         free_expression_stack(&switch_expr_stack);
1054         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1055         __bail_on_rest_of_function = 0;
1056 }
1057
1058 static void parse_inline(struct expression *call)
1059 {
1060         struct symbol *base_type;
1061         int loop_num_bak = loop_num;
1062         int final_pass_bak = final_pass;
1063         char *cur_func_bak = cur_func;
1064         struct statement_list *big_statement_stack_bak = big_statement_stack;
1065         struct expression_list *big_expression_stack_bak = big_expression_stack;
1066         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1067         struct symbol *cur_func_sym_bak = cur_func_sym;
1068
1069         __pass_to_client(call, INLINE_FN_START);
1070         final_pass = 0;  /* don't print anything */
1071         __inline_fn = call;
1072
1073         base_type = get_base_type(call->fn->symbol);
1074         cur_func_sym = call->fn->symbol;
1075         if (call->fn->symbol->ident)
1076                 cur_func = call->fn->symbol->ident->name;
1077         else
1078                 cur_func = NULL;
1079         set_position(call->fn->symbol->pos);
1080
1081         save_all_states();
1082         nullify_all_states();
1083         big_statement_stack = NULL;
1084         big_expression_stack = NULL;
1085         switch_expr_stack = NULL;
1086
1087         sm_debug("inline function:  %s\n", cur_func);
1088         __unnullify_path();
1089         loop_num = 0;
1090         __pass_to_client(call->fn->symbol, FUNC_DEF_HOOK);
1091         __pass_to_client(call->fn->symbol, AFTER_DEF_HOOK);
1092         __split_stmt(base_type->stmt);
1093         __split_stmt(base_type->inline_stmt);
1094         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1095         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1096
1097         free_expression_stack(&switch_expr_stack);
1098         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1099         nullify_path();
1100
1101         loop_num = loop_num_bak;
1102         final_pass = final_pass_bak;
1103         cur_func_sym = cur_func_sym_bak;
1104         cur_func = cur_func_bak;
1105         big_statement_stack = big_statement_stack_bak;
1106         big_expression_stack = big_expression_stack_bak;
1107         switch_expr_stack = switch_expr_stack_bak;
1108
1109         restore_all_states();
1110         set_position(call->pos);
1111         __inline_fn = NULL;
1112         __pass_to_client(call, INLINE_FN_END);
1113 }
1114
1115 static struct symbol_list *inlines_called;
1116 static void add_inline_function(struct symbol *sym)
1117 {
1118         static struct symbol_list *already_added;
1119         struct symbol *tmp;
1120
1121         FOR_EACH_PTR(already_added, tmp) {
1122                 if (tmp == sym)
1123                         return;
1124         } END_FOR_EACH_PTR(tmp);
1125
1126         add_ptr_list(&already_added, sym);
1127         add_ptr_list(&inlines_called, sym);
1128 }
1129
1130 static void process_inlines()
1131 {
1132         struct symbol *tmp;
1133
1134         FOR_EACH_PTR(inlines_called, tmp) {
1135                 split_function(tmp);
1136         } END_FOR_EACH_PTR(tmp);
1137         free_ptr_list(&inlines_called);
1138 }
1139
1140 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1141 {
1142         struct symbol *sym;
1143
1144         FOR_EACH_PTR_REVERSE(big_list, sym) {
1145                 if (!sym->scope)
1146                         continue;
1147                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1148                         return sym;
1149                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1150                         return sym;
1151         } END_FOR_EACH_PTR_REVERSE(sym);
1152
1153         return NULL;
1154 }
1155
1156 static void split_inlines_in_scope(struct symbol *sym)
1157 {
1158         struct symbol *base;
1159         struct symbol_list *scope_list;
1160         int stream;
1161
1162         scope_list = sym->scope->symbols;
1163         stream = sym->pos.stream;
1164
1165         /* find the last static symbol in the file */
1166         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1167                 if (sym->pos.stream != stream)
1168                         continue;
1169                 if (sym->type != SYM_NODE)
1170                         continue;
1171                 base = get_base_type(sym);
1172                 if (!base)
1173                         continue;
1174                 if (base->type != SYM_FN)
1175                         continue;
1176                 if (!base->inline_stmt)
1177                         continue;
1178                 add_inline_function(sym);
1179         } END_FOR_EACH_PTR_REVERSE(sym);
1180
1181         process_inlines();
1182 }
1183
1184 static void split_inlines(struct symbol_list *sym_list)
1185 {
1186         struct symbol *sym;
1187
1188         sym = get_last_scoped_symbol(sym_list, 0);
1189         if (sym)
1190                 split_inlines_in_scope(sym);
1191         sym = get_last_scoped_symbol(sym_list, 1);
1192         if (sym)
1193                 split_inlines_in_scope(sym);
1194 }
1195
1196 static void split_functions(struct symbol_list *sym_list)
1197 {
1198         struct symbol *sym;
1199
1200         FOR_EACH_PTR(sym_list, sym) {
1201                 set_position(sym->pos);
1202                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1203                         split_function(sym);
1204                         process_inlines();
1205                 } else {
1206                         __pass_to_client(sym, BASE_HOOK);
1207                         fake_global_assign(sym);
1208                 }
1209         } END_FOR_EACH_PTR(sym);
1210         split_inlines(sym_list);
1211         __pass_to_client(sym_list, END_FILE_HOOK);
1212 }
1213
1214 void smatch(int argc, char **argv)
1215 {
1216
1217         struct string_list *filelist = NULL;
1218         struct symbol_list *sym_list;
1219
1220         if (argc < 2) {
1221                 printf("Usage:  smatch [--debug] <filename.c>\n");
1222                 exit(1);
1223         }
1224         sparse_initialize(argc, argv, &filelist);
1225         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1226                 if (option_file_output) {
1227                         char buf[256];
1228
1229                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1230                         sm_outfd = fopen(buf, "w");
1231                         if (!sm_outfd) {
1232                                 printf("Error:  Cannot open %s\n", base_file);
1233                                 exit(1);
1234                         }
1235                 }
1236                 sym_list = sparse_keep_tokens(base_file);
1237                 split_functions(sym_list);
1238         } END_FOR_EACH_PTR_NOTAG(base_file);
1239 }