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