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