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 __in_fake_assign;
  21 int final_pass;
  22 int __inline_call;
  23 struct expression  *__inline_fn;
  24
  25 static int __smatch_lineno = 0;
  26
  27 static char *base_file;
  28 static const char *filename;
  29 static char *pathname;
  30 static char *full_filename;
  31 static char *cur_func;
  32 static int loop_count;
  33 int __expr_stmt_count;
  34 int __in_function_def;
  35 static struct expression_list *switch_expr_stack = NULL;
  36 static struct expression_list *post_op_stack = NULL;
  37
  38 struct expression_list *big_expression_stack;
  39 struct statement_list *big_statement_stack;
  40 int __in_pre_condition = 0;
  41 int __bail_on_rest_of_function = 0;
  42 char *get_function(void) { return cur_func; }
  43 int get_lineno(void) { return __smatch_lineno; }
  44 int inside_loop(void) { return !!loop_count; }
  45 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
  46 int in_expression_statement(void) { return !!__expr_stmt_count; }
  47
  48 static void split_symlist(struct symbol_list *sym_list);
  49 static void split_declaration(struct symbol_list *sym_list);
  50 static void split_expr_list(struct expression_list *expr_list);
  51 static void add_inline_function(struct symbol *sym);
  52 static void parse_inline(struct expression *expr);
  53
  54 int option_assume_loops = 0;
  55 int option_known_conditions = 0;
  56 int option_two_passes = 0;
  57 struct symbol *cur_func_sym = NULL;
  58
  59 int outside_of_function(void)
  60 {
  61         return cur_func_sym == NULL;
  62 }
  63
  64 const char *get_filename(void)
  65 {
  66         if (option_info)
  67                 return base_file;
  68         if (option_full_path)
  69                 return full_filename;
  70         return filename;
  71 }
  72
  73 const char *get_base_file(void)
  74 {
  75         return base_file;
  76 }
  77
  78 static void set_position(struct position pos)
  79 {
  80         int len;
  81         static int prev_stream = -1;
  82
  83         if (pos.stream == 0 && pos.line == 0)
  84                 return;
  85
  86         __smatch_lineno = pos.line;
  87
  88         if (pos.stream == prev_stream)
  89                 return;
  90
  91         filename = stream_name(pos.stream);
  92
  93         free(full_filename);
  94         pathname = getcwd(NULL, 0);
  95         if (pathname) {
  96                 len = strlen(pathname) + 1 + strlen(filename) + 1;
  97                 full_filename = malloc(len);
  98                 snprintf(full_filename, len, "%s/%s", pathname, filename);
  99         } else {
 100                 full_filename = alloc_string(filename);
 101         }
 102         free(pathname);
 103 }
 104
 105 static int is_inline_func(struct expression *expr)
 106 {
 107         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 108                 return 0;
 109         if (expr->symbol->ctype.modifiers & MOD_INLINE)
 110                 return 1;
 111         return 0;
 112 }
 113
 114 static int is_noreturn_func(struct expression *expr)
 115 {
 116         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 117                 return 0;
 118         if (expr->symbol->ctype.modifiers & MOD_NORETURN)
 119                 return 1;
 120         return 0;
 121 }
 122
 123 int inlinable(struct expression *expr)
 124 {
 125         struct symbol *sym;
 126
 127         if (__inline_fn)  /* don't nest */
 128                 return 0;
 129
 130         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 131                 return 0;
 132         if (is_no_inline_function(expr->symbol->ident->name))
 133                 return 0;
 134         sym = get_base_type(expr->symbol);
 135         if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
 136                 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
 137                         return 1;
 138                 return 0;
 139         }
 140         if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
 141                 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
 142                         return 1;
 143                 return 0;
 144         }
 145         return 0;
 146 }
 147
 148 void __process_post_op_stack(void)
 149 {
 150         struct expression *expr;
 151
 152         FOR_EACH_PTR(post_op_stack, expr) {
 153                 __pass_to_client(expr, OP_HOOK);
 154         } END_FOR_EACH_PTR(expr);
 155
 156         __free_ptr_list((struct ptr_list **)&post_op_stack);
 157 }
 158
 159 void __split_expr(struct expression *expr)
 160 {
 161         if (!expr)
 162                 return;
 163
 164         // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
 165
 166         if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
 167                 return;
 168         if (__in_fake_assign >= 4)  /* don't allow too much nesting */
 169                 return;
 170
 171         push_expression(&big_expression_stack, expr);
 172         set_position(expr->pos);
 173         __pass_to_client(expr, EXPR_HOOK);
 174
 175         switch (expr->type) {
 176         case EXPR_PREOP:
 177                 if (expr->op == '*')
 178                         __pass_to_client(expr, DEREF_HOOK);
 179                 __split_expr(expr->unop);
 180                 __pass_to_client(expr, OP_HOOK);
 181                 break;
 182         case EXPR_POSTOP:
 183                 __split_expr(expr->unop);
 184                 push_expression(&post_op_stack, expr);
 185                 break;
 186         case EXPR_STATEMENT:
 187                 __expr_stmt_count++;
 188                 __split_stmt(expr->statement);
 189                 __expr_stmt_count--;
 190                 break;
 191         case EXPR_LOGICAL:
 192         case EXPR_COMPARE:
 193                 __pass_to_client(expr, LOGIC_HOOK);
 194                 __handle_logic(expr);
 195                 break;
 196         case EXPR_BINOP:
 197                 __pass_to_client(expr, BINOP_HOOK);
 198         case EXPR_COMMA:
 199                 __split_expr(expr->left);
 200                 __process_post_op_stack();
 201                 __split_expr(expr->right);
 202                 break;
 203         case EXPR_ASSIGNMENT: {
 204                 struct expression *tmp;
 205
 206                 if (!expr->right)
 207                         break;
 208
 209                 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
 210
 211                 /* foo = !bar() */
 212                 if (__handle_condition_assigns(expr))
 213                         break;
 214                 /* foo = (x < 5 ? foo : 5); */
 215                 if (__handle_select_assigns(expr))
 216                         break;
 217                 /* foo = ({frob(); frob(); frob(); 1;}) */
 218                 if (__handle_expr_statement_assigns(expr))
 219                         break;
 220
 221                 __split_expr(expr->right);
 222                 if (outside_of_function())
 223                         __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
 224                 else
 225                         __pass_to_client(expr, ASSIGNMENT_HOOK);
 226
 227                 __fake_struct_member_assignments(expr);
 228
 229                 tmp = strip_expr(expr->right);
 230                 if (tmp->type == EXPR_CALL)
 231                         __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
 232                 if (get_macro_name(tmp->pos) &&
 233                     get_macro_name(expr->pos) != get_macro_name(tmp->pos))
 234                         __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
 235                 __split_expr(expr->left);
 236                 break;
 237         }
 238         case EXPR_DEREF:
 239                 __pass_to_client(expr, DEREF_HOOK);
 240                 __split_expr(expr->deref);
 241                 break;
 242         case EXPR_SLICE:
 243                 __split_expr(expr->base);
 244                 break;
 245         case EXPR_CAST:
 246         case EXPR_FORCE_CAST:
 247                 __pass_to_client(expr, CAST_HOOK);
 248                 __split_expr(expr->cast_expression);
 249                 break;
 250         case EXPR_SIZEOF:
 251                 if (expr->cast_expression)
 252                         __pass_to_client(strip_parens(expr->cast_expression),
 253                                          SIZEOF_HOOK);
 254                 break;
 255         case EXPR_OFFSETOF:
 256         case EXPR_ALIGNOF:
 257                 evaluate_expression(expr);
 258                 break;
 259         case EXPR_CONDITIONAL:
 260         case EXPR_SELECT:
 261                 if (known_condition_true(expr->conditional)) {
 262                         __split_expr(expr->cond_true);
 263                         break;
 264                 }
 265                 if (known_condition_false(expr->conditional)) {
 266                         __split_expr(expr->cond_false);
 267                         break;
 268                 }
 269                 __pass_to_client(expr, SELECT_HOOK);
 270                 __split_whole_condition(expr->conditional);
 271                 __split_expr(expr->cond_true);
 272                 __push_true_states();
 273                 __use_false_states();
 274                 __split_expr(expr->cond_false);
 275                 __merge_true_states();
 276                 break;
 277         case EXPR_CALL:
 278                 if (sym_name_is("__builtin_constant_p", expr->fn))
 279                         break;
 280                 split_expr_list(expr->args);
 281                 __split_expr(expr->fn);
 282                 if (is_inline_func(expr->fn))
 283                         add_inline_function(expr->fn->symbol);
 284                 if (inlinable(expr->fn))
 285                         __inline_call = 1;
 286                 __process_post_op_stack();
 287                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 288                 __inline_call = 0;
 289                 if (inlinable(expr->fn)) {
 290                         parse_inline(expr);
 291                 }
 292                 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
 293                 if (is_noreturn_func(expr->fn))
 294                         nullify_path();
 295                 break;
 296         case EXPR_INITIALIZER:
 297                 split_expr_list(expr->expr_list);
 298                 break;
 299         case EXPR_IDENTIFIER:
 300                 __split_expr(expr->ident_expression);
 301                 break;
 302         case EXPR_INDEX:
 303                 __split_expr(expr->idx_expression);
 304                 break;
 305         case EXPR_POS:
 306                 __split_expr(expr->init_expr);
 307                 break;
 308         case EXPR_SYMBOL:
 309                 __pass_to_client(expr, SYM_HOOK);
 310                 break;
 311         case EXPR_STRING:
 312                 __pass_to_client(expr, STRING_HOOK);
 313                 break;
 314         default:
 315                 break;
 316         };
 317         pop_expression(&big_expression_stack);
 318 }
 319
 320 static int is_forever_loop(struct statement *stmt)
 321 {
 322         struct expression *expr;
 323
 324         expr = strip_expr(stmt->iterator_pre_condition);
 325         if (!expr)
 326                 expr = stmt->iterator_post_condition;
 327         if (!expr) {
 328                 /* this is a for(;;) loop... */
 329                 return 1;
 330         }
 331
 332         if (expr->type == EXPR_VALUE && expr->value == 1)
 333                 return 1;
 334
 335         return 0;
 336 }
 337
 338 static int loop_num;
 339 static char *get_loop_name(int num)
 340 {
 341         char buf[256];
 342
 343         snprintf(buf, 255, "-loop%d", num);
 344         buf[255] = '\0';
 345         return alloc_sname(buf);
 346 }
 347
 348 /*
 349  * Pre Loops are while and for loops.
 350  */
 351 static void handle_pre_loop(struct statement *stmt)
 352 {
 353         int once_through; /* we go through the loop at least once */
 354         struct sm_state *extra_sm = NULL;
 355         int unchanged = 0;
 356         char *loop_name;
 357         struct state_list *slist = NULL;
 358         struct sm_state *sm = NULL;
 359
 360         loop_name = get_loop_name(loop_num);
 361         loop_num++;
 362
 363         __split_stmt(stmt->iterator_pre_statement);
 364
 365         once_through = implied_condition_true(stmt->iterator_pre_condition);
 366
 367         loop_count++;
 368         __push_continues();
 369         __push_breaks();
 370
 371         __merge_gotos(loop_name);
 372
 373         extra_sm = __extra_handle_canonical_loops(stmt, &slist);
 374         __in_pre_condition++;
 375         __pass_to_client(stmt, PRELOOP_HOOK);
 376         __split_whole_condition(stmt->iterator_pre_condition);
 377         __in_pre_condition--;
 378         FOR_EACH_PTR(slist, sm) {
 379                 set_state(sm->owner, sm->name, sm->sym, sm->state);
 380         } END_FOR_EACH_PTR(sm);
 381         free_slist(&slist);
 382         if (extra_sm)
 383                 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
 384
 385         if (option_assume_loops)
 386                 once_through = 1;
 387
 388         __split_stmt(stmt->iterator_statement);
 389         __warn_on_silly_pre_loops();
 390         if (is_forever_loop(stmt)) {
 391                 struct state_list *slist;
 392
 393                 __save_gotos(loop_name);
 394
 395                 __push_fake_cur_slist();
 396                 __split_stmt(stmt->iterator_post_statement);
 397                 slist = __pop_fake_cur_slist();
 398
 399                 __discard_continues();
 400                 __discard_false_states();
 401                 __use_breaks();
 402
 403                 if (!__path_is_null())
 404                         __merge_slist_into_cur(slist);
 405                 free_slist(&slist);
 406         } else {
 407                 __merge_continues();
 408                 unchanged = __iterator_unchanged(extra_sm);
 409                 __split_stmt(stmt->iterator_post_statement);
 410                 __save_gotos(loop_name);
 411                 __split_whole_condition(stmt->iterator_pre_condition);
 412                 nullify_path();
 413                 __merge_false_states();
 414                 if (once_through)
 415                         __discard_false_states();
 416                 else
 417                         __merge_false_states();
 418
 419                 if (extra_sm && unchanged)
 420                         __extra_pre_loop_hook_after(extra_sm,
 421                                                 stmt->iterator_post_statement,
 422                                                 stmt->iterator_pre_condition);
 423                 __merge_breaks();
 424         }
 425         loop_count--;
 426 }
 427
 428 /*
 429  * Post loops are do {} while();
 430  */
 431 static void handle_post_loop(struct statement *stmt)
 432 {
 433         char *loop_name;
 434
 435         loop_name = get_loop_name(loop_num);
 436         loop_num++;
 437         loop_count++;
 438
 439         __push_continues();
 440         __push_breaks();
 441         __merge_gotos(loop_name);
 442         __split_stmt(stmt->iterator_statement);
 443         __merge_continues();
 444         if (!is_zero(stmt->iterator_post_condition))
 445                 __save_gotos(loop_name);
 446
 447         if (is_forever_loop(stmt)) {
 448                 __use_breaks();
 449         } else {
 450                 __split_whole_condition(stmt->iterator_post_condition);
 451                 __use_false_states();
 452                 __merge_breaks();
 453         }
 454         loop_count--;
 455 }
 456
 457 static int empty_statement(struct statement *stmt)
 458 {
 459         if (!stmt)
 460                 return 0;
 461         if (stmt->type == STMT_EXPRESSION && !stmt->expression)
 462                 return 1;
 463         return 0;
 464 }
 465
 466 static int last_stmt_on_same_line()
 467 {
 468         struct statement *stmt;
 469         int i = 0;
 470
 471         FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
 472                 if (!i++)
 473                         continue;
 474                 if  (stmt->pos.line == get_lineno())
 475                         return 1;
 476                 return 0;
 477         } END_FOR_EACH_PTR_REVERSE(stmt);
 478         return 0;
 479 }
 480
 481 static struct statement *last_stmt;
 482 static int is_last_stmt(struct statement *stmt)
 483 {
 484         if (stmt == last_stmt)
 485                 return 1;
 486         return 0;
 487 }
 488
 489 static void print_unreached_initializers(struct symbol_list *sym_list)
 490 {
 491         struct symbol *sym;
 492
 493         FOR_EACH_PTR(sym_list, sym) {
 494                 if (sym->initializer)
 495                         sm_msg("info: '%s' is not actually initialized (unreached code).",
 496                                 (sym->ident ? sym->ident->name : "this variable"));
 497         } END_FOR_EACH_PTR(sym);
 498 }
 499
 500 static void print_unreached(struct statement *stmt)
 501 {
 502         static int print = 1;
 503
 504         if (__inline_fn)
 505                 return;
 506
 507         if (!__path_is_null()) {
 508                 print = 1;
 509                 return;
 510         }
 511         if (!print)
 512                 return;
 513
 514         switch (stmt->type) {
 515         case STMT_COMPOUND: /* after a switch before a case stmt */
 516         case STMT_RANGE:
 517         case STMT_CASE:
 518         case STMT_LABEL:
 519                 return;
 520         case STMT_DECLARATION: /* switch (x) { int a; case foo: ... */
 521                 print_unreached_initializers(stmt->declaration);
 522                 return;
 523         case STMT_RETURN: /* gcc complains if you don't have a return statement */
 524                 if (is_last_stmt(stmt))
 525                         return;
 526                 break;
 527         case STMT_GOTO:
 528                 /* people put extra breaks inside switch statements */
 529                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE &&
 530                     strcmp(stmt->goto_label->ident->name, "break") == 0)
 531                         return;
 532                 break;
 533         default:
 534                 break;
 535         }
 536         if (empty_statement(stmt))
 537                 return;
 538         if (!option_spammy)
 539                 return;
 540         sm_msg("info: ignoring unreachable code.");
 541         print = 0;
 542 }
 543
 544 static void split_asm_constraints(struct expression_list *expr_list)
 545 {
 546         struct expression *expr;
 547         int state = 0;
 548
 549         FOR_EACH_PTR(expr_list, expr) {
 550                 switch (state) {
 551                 case 0: /* identifier */
 552                 case 1: /* constraint */
 553                         state++;
 554                         continue;
 555                 case 2: /* expression */
 556                         state = 0;
 557                         __split_expr(expr);
 558                         continue;
 559                 }
 560         } END_FOR_EACH_PTR(expr);
 561 }
 562
 563 static int is_case_val(struct statement *stmt, sval_t sval)
 564 {
 565         sval_t case_sval;
 566
 567         if (stmt->type != STMT_CASE)
 568                 return 0;
 569         if (!stmt->case_expression) {
 570                 __set_default();
 571                 return 1;
 572         }
 573         if (!get_value(stmt->case_expression, &case_sval))
 574                 return 0;
 575         if (case_sval.value == sval.value)
 576                 return 1;
 577         return 0;
 578 }
 579
 580 static void split_known_switch(struct statement *stmt, sval_t sval)
 581 {
 582         struct statement *tmp;
 583
 584         __split_expr(stmt->switch_expression);
 585
 586         push_expression(&switch_expr_stack, stmt->switch_expression);
 587         __save_switch_states(top_expression(switch_expr_stack));
 588         nullify_path();
 589         __push_default();
 590         __push_breaks();
 591
 592         stmt = stmt->switch_statement;
 593
 594         if (!last_stmt)
 595                 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 596
 597         __push_scope_hooks();
 598         FOR_EACH_PTR(stmt->stmts, tmp) {
 599                 __smatch_lineno = tmp->pos.line;
 600                 if (is_case_val(tmp, sval)) {
 601                         __merge_switches(top_expression(switch_expr_stack),
 602                                          stmt->case_expression);
 603                         __pass_case_to_client(top_expression(switch_expr_stack),
 604                                               stmt->case_expression);
 605                 }
 606                 if (__path_is_null())
 607                         continue;
 608                 __split_stmt(tmp);
 609                 if (__path_is_null()) {
 610                         __set_default();
 611                         goto out;
 612                 }
 613         } END_FOR_EACH_PTR(tmp);
 614 out:
 615         __call_scope_hooks();
 616         if (!__pop_default())
 617                 __merge_switches(top_expression(switch_expr_stack),
 618                                  NULL);
 619         __discard_switches();
 620         __merge_breaks();
 621         pop_expression(&switch_expr_stack);
 622 }
 623
 624 void __split_stmt(struct statement *stmt)
 625 {
 626         sval_t sval;
 627
 628         if (!stmt)
 629                 goto out;
 630
 631         if (out_of_memory() || __bail_on_rest_of_function) {
 632                 static char *printed = NULL;
 633
 634                 if (printed != cur_func)
 635                         sm_msg("Function too hairy.  Giving up.");
 636                 final_pass = 0;  /* turn off sm_msg() from here */
 637                 printed = cur_func;
 638                 return;
 639         }
 640
 641         add_ptr_list(&big_statement_stack, stmt);
 642         free_expression_stack(&big_expression_stack);
 643         set_position(stmt->pos);
 644         print_unreached(stmt);
 645         __pass_to_client(stmt, STMT_HOOK);
 646
 647         switch (stmt->type) {
 648         case STMT_DECLARATION:
 649                 split_declaration(stmt->declaration);
 650                 break;
 651         case STMT_RETURN:
 652                 __split_expr(stmt->ret_value);
 653                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 654                 nullify_path();
 655                 break;
 656         case STMT_EXPRESSION:
 657                 __split_expr(stmt->expression);
 658                 break;
 659         case STMT_COMPOUND: {
 660                 struct statement *tmp;
 661
 662                 if (!last_stmt)
 663                         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 664                 __push_scope_hooks();
 665                 FOR_EACH_PTR(stmt->stmts, tmp) {
 666                         __split_stmt(tmp);
 667                 } END_FOR_EACH_PTR(tmp);
 668                 __call_scope_hooks();
 669                 break;
 670         }
 671         case STMT_IF:
 672                 if (known_condition_true(stmt->if_conditional)) {
 673                         __split_stmt(stmt->if_true);
 674                         break;
 675                 }
 676                 if (known_condition_false(stmt->if_conditional)) {
 677                         __split_stmt(stmt->if_false);
 678                         break;
 679                 }
 680                 if (option_known_conditions &&
 681                     implied_condition_true(stmt->if_conditional)) {
 682                         sm_info("this condition is true.");
 683                         __split_stmt(stmt->if_true);
 684                         break;
 685                 }
 686                 if (option_known_conditions &&
 687                     implied_condition_false(stmt->if_conditional)) {
 688                         sm_info("this condition is false.");
 689                         __split_stmt(stmt->if_false);
 690                         break;
 691                 }
 692                 __split_whole_condition(stmt->if_conditional);
 693                 __split_stmt(stmt->if_true);
 694                 if (empty_statement(stmt->if_true) &&
 695                         last_stmt_on_same_line() &&
 696                         !get_macro_name(stmt->if_true->pos))
 697                         sm_msg("warn: if();");
 698                 __push_true_states();
 699                 __use_false_states();
 700                 __split_stmt(stmt->if_false);
 701                 __merge_true_states();
 702                 break;
 703         case STMT_ITERATOR:
 704                 if (stmt->iterator_pre_condition)
 705                         handle_pre_loop(stmt);
 706                 else if (stmt->iterator_post_condition)
 707                         handle_post_loop(stmt);
 708                 else {
 709                         // these are for(;;) type loops.
 710                         handle_pre_loop(stmt);
 711                 }
 712                 break;
 713         case STMT_SWITCH:
 714                 if (get_value(stmt->switch_expression, &sval)) {
 715                         split_known_switch(stmt, sval);
 716                         break;
 717                 }
 718                 __split_expr(stmt->switch_expression);
 719                 push_expression(&switch_expr_stack, stmt->switch_expression);
 720                 __save_switch_states(top_expression(switch_expr_stack));
 721                 nullify_path();
 722                 __push_default();
 723                 __push_breaks();
 724                 __split_stmt(stmt->switch_statement);
 725                 if (!__pop_default())
 726                         __merge_switches(top_expression(switch_expr_stack),
 727                                       NULL);
 728                 __discard_switches();
 729                 __merge_breaks();
 730                 pop_expression(&switch_expr_stack);
 731                 break;
 732         case STMT_CASE:
 733                 __merge_switches(top_expression(switch_expr_stack),
 734                                       stmt->case_expression);
 735                 __pass_case_to_client(top_expression(switch_expr_stack),
 736                                       stmt->case_expression);
 737                 if (!stmt->case_expression)
 738                         __set_default();
 739                 __split_expr(stmt->case_expression);
 740                 __split_expr(stmt->case_to);
 741                 __split_stmt(stmt->case_statement);
 742                 break;
 743         case STMT_LABEL:
 744                 if (stmt->label_identifier &&
 745                     stmt->label_identifier->type == SYM_LABEL &&
 746                     stmt->label_identifier->ident) {
 747                         loop_count = 1000000;
 748                         __merge_gotos(stmt->label_identifier->ident->name);
 749                 }
 750                 __split_stmt(stmt->label_statement);
 751                 break;
 752         case STMT_GOTO:
 753                 __split_expr(stmt->goto_expression);
 754                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 755                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 756                                 __process_breaks();
 757                         } else if (!strcmp(stmt->goto_label->ident->name,
 758                                            "continue")) {
 759                                 __process_continues();
 760                         }
 761                 } else if (stmt->goto_label &&
 762                            stmt->goto_label->type == SYM_LABEL &&
 763                            stmt->goto_label->ident) {
 764                         __save_gotos(stmt->goto_label->ident->name);
 765                 }
 766                 nullify_path();
 767                 break;
 768         case STMT_NONE:
 769                 break;
 770         case STMT_ASM:
 771                 __pass_to_client(stmt, ASM_HOOK);
 772                 __split_expr(stmt->asm_string);
 773                 split_asm_constraints(stmt->asm_outputs);
 774                 split_asm_constraints(stmt->asm_inputs);
 775                 split_asm_constraints(stmt->asm_clobbers);
 776                 break;
 777         case STMT_CONTEXT:
 778                 break;
 779         case STMT_RANGE:
 780                 __split_expr(stmt->range_expression);
 781                 __split_expr(stmt->range_low);
 782                 __split_expr(stmt->range_high);
 783                 break;
 784         }
 785         __pass_to_client(stmt, STMT_HOOK_AFTER);
 786 out:
 787         __process_post_op_stack();
 788 }
 789
 790 static void split_expr_list(struct expression_list *expr_list)
 791 {
 792         struct expression *expr;
 793
 794         FOR_EACH_PTR(expr_list, expr) {
 795                 __split_expr(expr);
 796                 __process_post_op_stack();
 797         } END_FOR_EACH_PTR(expr);
 798 }
 799
 800 static void split_sym(struct symbol *sym)
 801 {
 802         if (!sym)
 803                 return;
 804         if (!(sym->namespace & NS_SYMBOL))
 805                 return;
 806
 807         __split_stmt(sym->stmt);
 808         __split_expr(sym->array_size);
 809         split_symlist(sym->arguments);
 810         split_symlist(sym->symbol_list);
 811         __split_stmt(sym->inline_stmt);
 812         split_symlist(sym->inline_symbol_list);
 813 }
 814
 815 static void split_symlist(struct symbol_list *sym_list)
 816 {
 817         struct symbol *sym;
 818
 819         FOR_EACH_PTR(sym_list, sym) {
 820                 split_sym(sym);
 821         } END_FOR_EACH_PTR(sym);
 822 }
 823
 824 typedef void (fake_cb)(struct expression *expr);
 825
 826 static int member_to_number(struct expression *expr, struct ident *member)
 827 {
 828         struct symbol *type, *tmp;
 829         char *name;
 830         int i;
 831
 832         if (!member)
 833                 return -1;
 834         name = member->name;
 835
 836         type = get_type(expr);
 837         if (!type || type->type != SYM_STRUCT)
 838                 return -1;
 839
 840         i = -1;
 841         FOR_EACH_PTR(type->symbol_list, tmp) {
 842                 i++;
 843                 if (!tmp->ident)
 844                         continue;
 845                 if (strcmp(name, tmp->ident->name) == 0)
 846                         return i;
 847         } END_FOR_EACH_PTR(tmp);
 848         return -1;
 849 }
 850
 851 static struct ident *number_to_member(struct expression *expr, int num)
 852 {
 853         struct symbol *type, *member;
 854         int i = 0;
 855
 856         type = get_type(expr);
 857         if (!type || type->type != SYM_STRUCT)
 858                 return NULL;
 859
 860         FOR_EACH_PTR(type->symbol_list, member) {
 861                 if (i == num)
 862                         return member->ident;
 863                 i++;
 864         } END_FOR_EACH_PTR(member);
 865         return NULL;
 866 }
 867
 868 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 869
 870 struct member_set {
 871         struct ident *ident;
 872         int set;
 873 };
 874
 875 static struct member_set *alloc_member_set(struct symbol *type)
 876 {
 877         struct member_set *member_set;
 878         struct symbol *member;
 879         int member_count;
 880         int member_idx;
 881
 882         member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 883         member_set = malloc(member_count * sizeof(*member_set));
 884         member_idx = 0;
 885         FOR_EACH_PTR(type->symbol_list, member) {
 886                 member_set[member_idx].ident = member->ident;
 887                 member_set[member_idx].set = 0;
 888                 member_idx++;
 889         } END_FOR_EACH_PTR(member);
 890
 891         return member_set;
 892 }
 893
 894 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
 895 {
 896         int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 897         int i;
 898
 899         for (i = 0; i < member_count; i++) {
 900                 if (member_set[i].ident == ident) {
 901                         member_set[i].set = 1;
 902                         return;
 903                 }
 904         }
 905 //      crap.  this is buggy.
 906 //      sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
 907 }
 908
 909 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
 910 {
 911         struct expression *deref, *assign;
 912         struct symbol *member, *member_type;
 913         int member_idx;
 914
 915         member_idx = 0;
 916         FOR_EACH_PTR(type->symbol_list, member) {
 917                 if (!member->ident || member_set[member_idx].set) {
 918                         member_idx++;
 919                         continue;
 920                 }
 921                 member_type = get_real_base_type(member);
 922                 if (!member_type || member_type->type == SYM_ARRAY) {
 923                         member_idx++;
 924                         continue;
 925                 }
 926                 /* TODO: this should be handled recursively and not ignored */
 927                 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION) {
 928                         member_idx++;
 929                         continue;
 930                 }
 931                 deref = member_expression(symbol, '.', member->ident);
 932                 assign = assign_expression(deref, zero_expr());
 933                 __split_expr(assign);
 934                 member_idx++;
 935         } END_FOR_EACH_PTR(member);
 936
 937 }
 938
 939 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 940 {
 941         struct expression *deref, *assign, *tmp;
 942         struct symbol *struct_type, *type;
 943         struct ident *member;
 944         int member_idx;
 945         struct member_set *member_set;
 946
 947         struct_type = get_type(symbol);
 948         if (!struct_type ||
 949             (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
 950                 return;
 951
 952         member_set = alloc_member_set(struct_type);
 953
 954         member_idx = 0;
 955         FOR_EACH_PTR(members, tmp) {
 956                 member = number_to_member(symbol, member_idx);
 957                 while (tmp->type == EXPR_IDENTIFIER) {
 958                         member = tmp->expr_ident;
 959                         member_idx = member_to_number(symbol, member);
 960                         tmp = tmp->ident_expression;
 961                 }
 962                 mark_member_as_set(struct_type, member_set, member);
 963                 member_idx++;
 964                 deref = member_expression(symbol, '.', member);
 965                 if (tmp->type == EXPR_INITIALIZER) {
 966                         type = get_type(deref);
 967                         if (type && type->type == SYM_ARRAY)
 968                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 969                         else
 970                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 971                 } else {
 972                         assign = assign_expression(deref, tmp);
 973                         fake_cb(assign);
 974                 }
 975         } END_FOR_EACH_PTR(tmp);
 976
 977         set_unset_to_zero(symbol, struct_type, member_set);
 978 }
 979
 980 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
 981 {
 982         fake_member_assigns_helper(symbol_expression(sym),
 983                                    sym->initializer->expr_list, fake_cb);
 984 }
 985
 986 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
 987 {
 988         struct expression *offset, *binop, *assign, *tmp;
 989         struct symbol *type;
 990         int idx;
 991
 992         idx = 0;
 993         FOR_EACH_PTR(expr_list, tmp) {
 994                 if (tmp->type == EXPR_INDEX) {
 995                         if (tmp->idx_from != tmp->idx_to)
 996                                 return;
 997                         idx = tmp->idx_from;
 998                         if (!tmp->idx_expression)
 999                                 goto next;
1000                         tmp = tmp->idx_expression;
1001                 }
1002                 offset = value_expr(idx);
1003                 binop = array_element_expression(array, offset);
1004                 if (tmp->type == EXPR_INITIALIZER) {
1005                         type = get_type(binop);
1006                         if (type && type->type == SYM_ARRAY)
1007                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1008                         else
1009                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1010                 } else {
1011                         assign = assign_expression(binop, tmp);
1012                         fake_cb(assign);
1013                 }
1014 next:
1015                 idx++;
1016         } END_FOR_EACH_PTR(tmp);
1017 }
1018
1019 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1020 {
1021         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1022 }
1023
1024 static void fake_assign_expr(struct symbol *sym)
1025 {
1026         struct expression *assign, *symbol;
1027
1028         symbol = symbol_expression(sym);
1029         assign = assign_expression(symbol, sym->initializer);
1030         __split_expr(assign);
1031 }
1032
1033 static void call_split_expr(struct expression *expr)
1034 {
1035         __split_expr(expr);
1036 }
1037
1038 static void do_initializer_stuff(struct symbol *sym)
1039 {
1040         if (!sym->initializer)
1041                 return;
1042
1043         if (sym->initializer->type == EXPR_INITIALIZER) {
1044                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1045                         fake_element_assigns(sym, call_split_expr);
1046                 else
1047                         fake_member_assigns(sym, call_split_expr);
1048         } else {
1049                 fake_assign_expr(sym);
1050         }
1051 }
1052
1053 static void split_declaration(struct symbol_list *sym_list)
1054 {
1055         struct symbol *sym;
1056
1057         FOR_EACH_PTR(sym_list, sym) {
1058                 __pass_to_client(sym, DECLARATION_HOOK);
1059                 do_initializer_stuff(sym);
1060                 split_sym(sym);
1061         } END_FOR_EACH_PTR(sym);
1062 }
1063
1064 static void call_global_assign_hooks(struct expression *assign)
1065 {
1066         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1067 }
1068
1069 static void fake_global_assign(struct symbol *sym)
1070 {
1071         struct expression *assign, *symbol;
1072
1073         if (get_real_base_type(sym)->type == SYM_ARRAY) {
1074                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1075                         fake_element_assigns(sym, call_global_assign_hooks);
1076                 } else if (sym->initializer) {
1077                         symbol = symbol_expression(sym);
1078                         assign = assign_expression(symbol, sym->initializer);
1079                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1080                 } else {
1081                         fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1082                 }
1083         } else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1084                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1085                         fake_member_assigns(sym, call_global_assign_hooks);
1086                 } else if (sym->initializer) {
1087                         symbol = symbol_expression(sym);
1088                         assign = assign_expression(symbol, sym->initializer);
1089                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1090                 } else {
1091                         fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1092                 }
1093         } else {
1094                 symbol = symbol_expression(sym);
1095                 if (sym->initializer)
1096                         assign = assign_expression(symbol, sym->initializer);
1097                 else
1098                         assign = assign_expression(symbol, zero_expr());
1099                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1100         }
1101 }
1102
1103 static void start_function_definition(struct symbol *sym)
1104 {
1105         __in_function_def = 1;
1106         __pass_to_client(sym, FUNC_DEF_HOOK);
1107         __in_function_def = 0;
1108         __pass_to_client(sym, AFTER_DEF_HOOK);
1109
1110 }
1111
1112 static void split_function(struct symbol *sym)
1113 {
1114         struct symbol *base_type = get_base_type(sym);
1115
1116         cur_func_sym = sym;
1117         if (sym->ident)
1118                 cur_func = sym->ident->name;
1119         __smatch_lineno = sym->pos.line;
1120         last_stmt = NULL;
1121         loop_count = 0;
1122         sm_debug("new function:  %s\n", cur_func);
1123         __slist_id = 0;
1124         if (option_two_passes) {
1125                 __unnullify_path();
1126                 loop_num = 0;
1127                 final_pass = 0;
1128                 start_function_definition(sym);
1129                 __split_stmt(base_type->stmt);
1130                 __split_stmt(base_type->inline_stmt);
1131                 nullify_path();
1132         }
1133         __unnullify_path();
1134         loop_num = 0;
1135         start_function_definition(sym);
1136         __split_stmt(base_type->stmt);
1137         __split_stmt(base_type->inline_stmt);
1138         __pass_to_client(sym, END_FUNC_HOOK);
1139         __pass_to_client(sym, AFTER_FUNC_HOOK);
1140         cur_func_sym = NULL;
1141         cur_func = NULL;
1142         clear_all_states();
1143         free_data_info_allocs();
1144         free_expression_stack(&switch_expr_stack);
1145         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1146         __bail_on_rest_of_function = 0;
1147 }
1148
1149 static void parse_inline(struct expression *call)
1150 {
1151         struct symbol *base_type;
1152         int loop_num_bak = loop_num;
1153         int final_pass_bak = final_pass;
1154         char *cur_func_bak = cur_func;
1155         struct statement_list *big_statement_stack_bak = big_statement_stack;
1156         struct expression_list *big_expression_stack_bak = big_expression_stack;
1157         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1158         struct symbol *cur_func_sym_bak = cur_func_sym;
1159
1160         __pass_to_client(call, INLINE_FN_START);
1161         final_pass = 0;  /* don't print anything */
1162         __inline_fn = call;
1163
1164         base_type = get_base_type(call->fn->symbol);
1165         cur_func_sym = call->fn->symbol;
1166         if (call->fn->symbol->ident)
1167                 cur_func = call->fn->symbol->ident->name;
1168         else
1169                 cur_func = NULL;
1170         set_position(call->fn->symbol->pos);
1171
1172         save_all_states();
1173         nullify_all_states();
1174         big_statement_stack = NULL;
1175         big_expression_stack = NULL;
1176         switch_expr_stack = NULL;
1177
1178         sm_debug("inline function:  %s\n", cur_func);
1179         __unnullify_path();
1180         loop_num = 0;
1181         start_function_definition(call->fn->symbol);
1182         __split_stmt(base_type->stmt);
1183         __split_stmt(base_type->inline_stmt);
1184         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1185         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1186
1187         free_expression_stack(&switch_expr_stack);
1188         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1189         nullify_path();
1190
1191         loop_num = loop_num_bak;
1192         final_pass = final_pass_bak;
1193         cur_func_sym = cur_func_sym_bak;
1194         cur_func = cur_func_bak;
1195         big_statement_stack = big_statement_stack_bak;
1196         big_expression_stack = big_expression_stack_bak;
1197         switch_expr_stack = switch_expr_stack_bak;
1198
1199         restore_all_states();
1200         set_position(call->pos);
1201         __inline_fn = NULL;
1202         __pass_to_client(call, INLINE_FN_END);
1203 }
1204
1205 static struct symbol_list *inlines_called;
1206 static void add_inline_function(struct symbol *sym)
1207 {
1208         static struct symbol_list *already_added;
1209         struct symbol *tmp;
1210
1211         FOR_EACH_PTR(already_added, tmp) {
1212                 if (tmp == sym)
1213                         return;
1214         } END_FOR_EACH_PTR(tmp);
1215
1216         add_ptr_list(&already_added, sym);
1217         add_ptr_list(&inlines_called, sym);
1218 }
1219
1220 static void process_inlines()
1221 {
1222         struct symbol *tmp;
1223
1224         FOR_EACH_PTR(inlines_called, tmp) {
1225                 split_function(tmp);
1226         } END_FOR_EACH_PTR(tmp);
1227         free_ptr_list(&inlines_called);
1228 }
1229
1230 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1231 {
1232         struct symbol *sym;
1233
1234         FOR_EACH_PTR_REVERSE(big_list, sym) {
1235                 if (!sym->scope)
1236                         continue;
1237                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1238                         return sym;
1239                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1240                         return sym;
1241         } END_FOR_EACH_PTR_REVERSE(sym);
1242
1243         return NULL;
1244 }
1245
1246 static void split_inlines_in_scope(struct symbol *sym)
1247 {
1248         struct symbol *base;
1249         struct symbol_list *scope_list;
1250         int stream;
1251
1252         scope_list = sym->scope->symbols;
1253         stream = sym->pos.stream;
1254
1255         /* find the last static symbol in the file */
1256         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1257                 if (sym->pos.stream != stream)
1258                         continue;
1259                 if (sym->type != SYM_NODE)
1260                         continue;
1261                 base = get_base_type(sym);
1262                 if (!base)
1263                         continue;
1264                 if (base->type != SYM_FN)
1265                         continue;
1266                 if (!base->inline_stmt)
1267                         continue;
1268                 add_inline_function(sym);
1269         } END_FOR_EACH_PTR_REVERSE(sym);
1270
1271         process_inlines();
1272 }
1273
1274 static void split_inlines(struct symbol_list *sym_list)
1275 {
1276         struct symbol *sym;
1277
1278         sym = get_last_scoped_symbol(sym_list, 0);
1279         if (sym)
1280                 split_inlines_in_scope(sym);
1281         sym = get_last_scoped_symbol(sym_list, 1);
1282         if (sym)
1283                 split_inlines_in_scope(sym);
1284 }
1285
1286 static void split_functions(struct symbol_list *sym_list)
1287 {
1288         struct symbol *sym;
1289
1290         FOR_EACH_PTR(sym_list, sym) {
1291                 set_position(sym->pos);
1292                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1293                         split_function(sym);
1294                         process_inlines();
1295                 } else {
1296                         __pass_to_client(sym, BASE_HOOK);
1297                         fake_global_assign(sym);
1298                 }
1299         } END_FOR_EACH_PTR(sym);
1300         split_inlines(sym_list);
1301         __pass_to_client(sym_list, END_FILE_HOOK);
1302 }
1303
1304 void smatch(int argc, char **argv)
1305 {
1306
1307         struct string_list *filelist = NULL;
1308         struct symbol_list *sym_list;
1309
1310         if (argc < 2) {
1311                 printf("Usage:  smatch [--debug] <filename.c>\n");
1312                 exit(1);
1313         }
1314         sparse_initialize(argc, argv, &filelist);
1315         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1316                 if (option_file_output) {
1317                         char buf[256];
1318
1319                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1320                         sm_outfd = fopen(buf, "w");
1321                         if (!sm_outfd) {
1322                                 printf("Error:  Cannot open %s\n", base_file);
1323                                 exit(1);
1324                         }
1325                 }
1326                 sym_list = sparse_keep_tokens(base_file);
1327                 split_functions(sym_list);
1328         } END_FOR_EACH_PTR_NOTAG(base_file);
1329 }