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         sm_msg("info: ignoring unreachable code.");
 530         print = 0;
 531 }
 532
 533 static void split_asm_constraints(struct expression_list *expr_list)
 534 {
 535         struct expression *expr;
 536         int state = 0;
 537
 538         FOR_EACH_PTR(expr_list, expr) {
 539                 switch (state) {
 540                 case 0: /* identifier */
 541                 case 1: /* constraint */
 542                         state++;
 543                         continue;
 544                 case 2: /* expression */
 545                         state = 0;
 546                         __split_expr(expr);
 547                         continue;
 548                 }
 549         } END_FOR_EACH_PTR(expr);
 550 }
 551
 552 static int is_case_val(struct statement *stmt, sval_t sval)
 553 {
 554         sval_t case_sval;
 555
 556         if (stmt->type != STMT_CASE)
 557                 return 0;
 558         if (!stmt->case_expression) {
 559                 __set_default();
 560                 return 1;
 561         }
 562         if (!get_value(stmt->case_expression, &case_sval))
 563                 return 0;
 564         if (case_sval.value == sval.value)
 565                 return 1;
 566         return 0;
 567 }
 568
 569 static void split_known_switch(struct statement *stmt, sval_t sval)
 570 {
 571         struct statement *tmp;
 572
 573         __split_expr(stmt->switch_expression);
 574
 575         push_expression(&switch_expr_stack, stmt->switch_expression);
 576         __save_switch_states(top_expression(switch_expr_stack));
 577         nullify_path();
 578         __push_default();
 579         __push_breaks();
 580
 581         stmt = stmt->switch_statement;
 582
 583         if (!last_stmt)
 584                 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 585
 586         __push_scope_hooks();
 587         FOR_EACH_PTR(stmt->stmts, tmp) {
 588                 __smatch_lineno = tmp->pos.line;
 589                 if (is_case_val(tmp, sval)) {
 590                         __merge_switches(top_expression(switch_expr_stack),
 591                                          stmt->case_expression);
 592                         __pass_case_to_client(top_expression(switch_expr_stack),
 593                                               stmt->case_expression);
 594                 }
 595                 if (__path_is_null())
 596                         continue;
 597                 __split_stmt(tmp);
 598                 if (__path_is_null()) {
 599                         __set_default();
 600                         goto out;
 601                 }
 602         } END_FOR_EACH_PTR(tmp);
 603 out:
 604         __call_scope_hooks();
 605         if (!__pop_default())
 606                 __merge_switches(top_expression(switch_expr_stack),
 607                                  NULL);
 608         __discard_switches();
 609         __merge_breaks();
 610         pop_expression(&switch_expr_stack);
 611 }
 612
 613 void __split_stmt(struct statement *stmt)
 614 {
 615         sval_t sval;
 616
 617         if (!stmt)
 618                 goto out;
 619
 620         if (out_of_memory() || __bail_on_rest_of_function) {
 621                 static char *printed = NULL;
 622
 623                 if (printed != cur_func)
 624                         sm_msg("Function too hairy.  Giving up.");
 625                 final_pass = 0;  /* turn off sm_msg() from here */
 626                 printed = cur_func;
 627                 return;
 628         }
 629
 630         add_ptr_list(&big_statement_stack, stmt);
 631         free_expression_stack(&big_expression_stack);
 632         set_position(stmt->pos);
 633         print_unreached(stmt);
 634         __pass_to_client(stmt, STMT_HOOK);
 635
 636         switch (stmt->type) {
 637         case STMT_DECLARATION:
 638                 split_declaration(stmt->declaration);
 639                 break;
 640         case STMT_RETURN:
 641                 __split_expr(stmt->ret_value);
 642                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 643                 nullify_path();
 644                 break;
 645         case STMT_EXPRESSION:
 646                 __split_expr(stmt->expression);
 647                 break;
 648         case STMT_COMPOUND: {
 649                 struct statement *tmp;
 650
 651                 if (!last_stmt)
 652                         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 653                 __push_scope_hooks();
 654                 FOR_EACH_PTR(stmt->stmts, tmp) {
 655                         __split_stmt(tmp);
 656                 } END_FOR_EACH_PTR(tmp);
 657                 __call_scope_hooks();
 658                 break;
 659         }
 660         case STMT_IF:
 661                 if (known_condition_true(stmt->if_conditional)) {
 662                         __split_stmt(stmt->if_true);
 663                         break;
 664                 }
 665                 if (known_condition_false(stmt->if_conditional)) {
 666                         __split_stmt(stmt->if_false);
 667                         break;
 668                 }
 669                 if (option_known_conditions &&
 670                     implied_condition_true(stmt->if_conditional)) {
 671                         sm_info("this condition is true.");
 672                         __split_stmt(stmt->if_true);
 673                         break;
 674                 }
 675                 if (option_known_conditions &&
 676                     implied_condition_false(stmt->if_conditional)) {
 677                         sm_info("this condition is false.");
 678                         __split_stmt(stmt->if_false);
 679                         break;
 680                 }
 681                 __split_whole_condition(stmt->if_conditional);
 682                 __split_stmt(stmt->if_true);
 683                 if (empty_statement(stmt->if_true) &&
 684                         last_stmt_on_same_line() &&
 685                         !get_macro_name(stmt->if_true->pos))
 686                         sm_msg("warn: if();");
 687                 __push_true_states();
 688                 __use_false_states();
 689                 __split_stmt(stmt->if_false);
 690                 __merge_true_states();
 691                 break;
 692         case STMT_ITERATOR:
 693                 if (stmt->iterator_pre_condition)
 694                         handle_pre_loop(stmt);
 695                 else if (stmt->iterator_post_condition)
 696                         handle_post_loop(stmt);
 697                 else {
 698                         // these are for(;;) type loops.
 699                         handle_pre_loop(stmt);
 700                 }
 701                 break;
 702         case STMT_SWITCH:
 703                 if (get_value(stmt->switch_expression, &sval)) {
 704                         split_known_switch(stmt, sval);
 705                         break;
 706                 }
 707                 __split_expr(stmt->switch_expression);
 708                 push_expression(&switch_expr_stack, stmt->switch_expression);
 709                 __save_switch_states(top_expression(switch_expr_stack));
 710                 nullify_path();
 711                 __push_default();
 712                 __push_breaks();
 713                 __split_stmt(stmt->switch_statement);
 714                 if (!__pop_default())
 715                         __merge_switches(top_expression(switch_expr_stack),
 716                                       NULL);
 717                 __discard_switches();
 718                 __merge_breaks();
 719                 pop_expression(&switch_expr_stack);
 720                 break;
 721         case STMT_CASE:
 722                 __merge_switches(top_expression(switch_expr_stack),
 723                                       stmt->case_expression);
 724                 __pass_case_to_client(top_expression(switch_expr_stack),
 725                                       stmt->case_expression);
 726                 if (!stmt->case_expression)
 727                         __set_default();
 728                 __split_expr(stmt->case_expression);
 729                 __split_expr(stmt->case_to);
 730                 __split_stmt(stmt->case_statement);
 731                 break;
 732         case STMT_LABEL:
 733                 if (stmt->label_identifier &&
 734                     stmt->label_identifier->type == SYM_LABEL &&
 735                     stmt->label_identifier->ident) {
 736                         loop_count = 1000000;
 737                         __merge_gotos(stmt->label_identifier->ident->name);
 738                 }
 739                 __split_stmt(stmt->label_statement);
 740                 break;
 741         case STMT_GOTO:
 742                 __split_expr(stmt->goto_expression);
 743                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 744                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 745                                 __process_breaks();
 746                         } else if (!strcmp(stmt->goto_label->ident->name,
 747                                            "continue")) {
 748                                 __process_continues();
 749                         }
 750                 } else if (stmt->goto_label &&
 751                            stmt->goto_label->type == SYM_LABEL &&
 752                            stmt->goto_label->ident) {
 753                         __save_gotos(stmt->goto_label->ident->name);
 754                 }
 755                 nullify_path();
 756                 break;
 757         case STMT_NONE:
 758                 break;
 759         case STMT_ASM:
 760                 __pass_to_client(stmt, ASM_HOOK);
 761                 __split_expr(stmt->asm_string);
 762                 split_asm_constraints(stmt->asm_outputs);
 763                 split_asm_constraints(stmt->asm_inputs);
 764                 split_asm_constraints(stmt->asm_clobbers);
 765                 break;
 766         case STMT_CONTEXT:
 767                 break;
 768         case STMT_RANGE:
 769                 __split_expr(stmt->range_expression);
 770                 __split_expr(stmt->range_low);
 771                 __split_expr(stmt->range_high);
 772                 break;
 773         }
 774 out:
 775         __process_post_op_stack();
 776 }
 777
 778 static void split_expr_list(struct expression_list *expr_list)
 779 {
 780         struct expression *expr;
 781
 782         FOR_EACH_PTR(expr_list, expr) {
 783                 __split_expr(expr);
 784                 __process_post_op_stack();
 785         } END_FOR_EACH_PTR(expr);
 786 }
 787
 788 static void split_sym(struct symbol *sym)
 789 {
 790         if (!sym)
 791                 return;
 792         if (!(sym->namespace & NS_SYMBOL))
 793                 return;
 794
 795         __split_stmt(sym->stmt);
 796         __split_expr(sym->array_size);
 797         split_symlist(sym->arguments);
 798         split_symlist(sym->symbol_list);
 799         __split_stmt(sym->inline_stmt);
 800         split_symlist(sym->inline_symbol_list);
 801 }
 802
 803 static void split_symlist(struct symbol_list *sym_list)
 804 {
 805         struct symbol *sym;
 806
 807         FOR_EACH_PTR(sym_list, sym) {
 808                 split_sym(sym);
 809         } END_FOR_EACH_PTR(sym);
 810 }
 811
 812 typedef void (fake_cb)(struct expression *expr);
 813
 814 static int member_to_number(struct expression *expr, struct ident *member)
 815 {
 816         struct symbol *type, *tmp;
 817         char *name;
 818         int i;
 819
 820         if (!member)
 821                 return -1;
 822         name = member->name;
 823
 824         type = get_type(expr);
 825         if (!type || type->type != SYM_STRUCT)
 826                 return -1;
 827
 828         i = -1;
 829         FOR_EACH_PTR(type->symbol_list, tmp) {
 830                 i++;
 831                 if (!tmp->ident)
 832                         continue;
 833                 if (strcmp(name, tmp->ident->name) == 0)
 834                         return i;
 835         } END_FOR_EACH_PTR(tmp);
 836         return -1;
 837 }
 838
 839 static struct ident *number_to_member(struct expression *expr, int num)
 840 {
 841         struct symbol *type, *member;
 842         int i = 0;
 843
 844         type = get_type(expr);
 845         if (!type || type->type != SYM_STRUCT)
 846                 return NULL;
 847
 848         FOR_EACH_PTR(type->symbol_list, member) {
 849                 if (i == num)
 850                         return member->ident;
 851                 i++;
 852         } END_FOR_EACH_PTR(member);
 853         return NULL;
 854 }
 855
 856 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 857
 858 struct member_set {
 859         struct ident *ident;
 860         int set;
 861 };
 862
 863 static struct member_set *alloc_member_set(struct symbol *type)
 864 {
 865         struct member_set *member_set;
 866         struct symbol *member;
 867         int member_count;
 868         int member_idx;
 869
 870         member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 871         member_set = malloc(member_count * sizeof(*member_set));
 872         member_idx = 0;
 873         FOR_EACH_PTR(type->symbol_list, member) {
 874                 member_set[member_idx].ident = member->ident;
 875                 member_set[member_idx].set = 0;
 876                 member_idx++;
 877         } END_FOR_EACH_PTR(member);
 878
 879         return member_set;
 880 }
 881
 882 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
 883 {
 884         int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 885         int i;
 886
 887         for (i = 0; i < member_count; i++) {
 888                 if (member_set[i].ident == ident) {
 889                         member_set[i].set = 1;
 890                         return;
 891                 }
 892         }
 893 //      crap.  this is buggy.
 894 //      sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
 895 }
 896
 897 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
 898 {
 899         struct expression *deref, *assign;
 900         struct symbol *member, *member_type;
 901         int member_idx;
 902
 903         member_idx = 0;
 904         FOR_EACH_PTR(type->symbol_list, member) {
 905                 if (!member->ident || member_set[member_idx].set) {
 906                         member_idx++;
 907                         continue;
 908                 }
 909                 member_type = get_real_base_type(member);
 910                 if (!member_type || member_type->type == SYM_ARRAY)
 911                         continue;
 912                 /* TODO: this should be handled recursively and not ignored */
 913                 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION)
 914                         continue;
 915                 deref = member_expression(symbol, '.', member->ident);
 916                 assign = assign_expression(deref, zero_expr());
 917                 __split_expr(assign);
 918                 member_idx++;
 919         } END_FOR_EACH_PTR(member);
 920
 921 }
 922
 923 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 924 {
 925         struct expression *deref, *assign, *tmp;
 926         struct symbol *struct_type, *type;
 927         struct ident *member;
 928         int member_idx;
 929         struct member_set *member_set;
 930
 931         struct_type = get_type(symbol);
 932         if (!struct_type ||
 933             (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
 934                 return;
 935
 936         member_set = alloc_member_set(struct_type);
 937
 938         member_idx = 0;
 939         FOR_EACH_PTR(members, tmp) {
 940                 member = number_to_member(symbol, member_idx);
 941                 while (tmp->type == EXPR_IDENTIFIER) {
 942                         member = tmp->expr_ident;
 943                         member_idx = member_to_number(symbol, member);
 944                         tmp = tmp->ident_expression;
 945                 }
 946                 mark_member_as_set(struct_type, member_set, member);
 947                 member_idx++;
 948                 deref = member_expression(symbol, '.', member);
 949                 if (tmp->type == EXPR_INITIALIZER) {
 950                         type = get_type(deref);
 951                         if (type && type->type == SYM_ARRAY)
 952                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 953                         else
 954                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 955                 } else {
 956                         assign = assign_expression(deref, tmp);
 957                         fake_cb(assign);
 958                 }
 959         } END_FOR_EACH_PTR(tmp);
 960
 961         set_unset_to_zero(symbol, struct_type, member_set);
 962 }
 963
 964 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
 965 {
 966         fake_member_assigns_helper(symbol_expression(sym),
 967                                    sym->initializer->expr_list, fake_cb);
 968 }
 969
 970 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
 971 {
 972         struct expression *offset, *binop, *assign, *tmp;
 973         struct symbol *type;
 974         int idx;
 975
 976         idx = 0;
 977         FOR_EACH_PTR(expr_list, tmp) {
 978                 if (tmp->type == EXPR_INDEX) {
 979                         if (tmp->idx_from != tmp->idx_to)
 980                                 return;
 981                         idx = tmp->idx_from;
 982                         if (!tmp->idx_expression)
 983                                 goto next;
 984                         tmp = tmp->idx_expression;
 985                 }
 986                 offset = value_expr(idx);
 987                 binop = array_element_expression(array, offset);
 988                 if (tmp->type == EXPR_INITIALIZER) {
 989                         type = get_type(binop);
 990                         if (type && type->type == SYM_ARRAY)
 991                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
 992                         else
 993                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
 994                 } else {
 995                         assign = assign_expression(binop, tmp);
 996                         fake_cb(assign);
 997                 }
 998 next:
 999                 idx++;
1000         } END_FOR_EACH_PTR(tmp);
1001 }
1002
1003 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1004 {
1005         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1006 }
1007
1008 static void fake_assign_expr(struct symbol *sym)
1009 {
1010         struct expression *assign, *symbol;
1011
1012         symbol = symbol_expression(sym);
1013         assign = assign_expression(symbol, sym->initializer);
1014         __split_expr(assign);
1015 }
1016
1017 static void call_split_expr(struct expression *expr)
1018 {
1019         __split_expr(expr);
1020 }
1021
1022 static void do_initializer_stuff(struct symbol *sym)
1023 {
1024         if (!sym->initializer)
1025                 return;
1026
1027         if (sym->initializer->type == EXPR_INITIALIZER) {
1028                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1029                         fake_element_assigns(sym, call_split_expr);
1030                 else
1031                         fake_member_assigns(sym, call_split_expr);
1032         } else {
1033                 fake_assign_expr(sym);
1034         }
1035 }
1036
1037 static void split_declaration(struct symbol_list *sym_list)
1038 {
1039         struct symbol *sym;
1040
1041         FOR_EACH_PTR(sym_list, sym) {
1042                 __pass_to_client(sym, DECLARATION_HOOK);
1043                 do_initializer_stuff(sym);
1044                 split_sym(sym);
1045         } END_FOR_EACH_PTR(sym);
1046 }
1047
1048 static void call_global_assign_hooks(struct expression *assign)
1049 {
1050         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1051 }
1052
1053 static void fake_global_assign(struct symbol *sym)
1054 {
1055         struct expression *assign, *symbol;
1056
1057         if (!sym->initializer)
1058                 return;
1059         if (sym->initializer->type == EXPR_INITIALIZER) {
1060                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1061                         fake_element_assigns(sym, call_global_assign_hooks);
1062                 else
1063                         fake_member_assigns(sym, call_global_assign_hooks);
1064         } else {
1065                 symbol = symbol_expression(sym);
1066                 assign = assign_expression(symbol, sym->initializer);
1067                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1068         }
1069 }
1070
1071 static void start_function_definition(struct symbol *sym)
1072 {
1073         __in_function_def = 1;
1074         __pass_to_client(sym, FUNC_DEF_HOOK);
1075         __in_function_def = 0;
1076         __pass_to_client(sym, AFTER_DEF_HOOK);
1077
1078 }
1079
1080 static void split_function(struct symbol *sym)
1081 {
1082         struct symbol *base_type = get_base_type(sym);
1083
1084         cur_func_sym = sym;
1085         if (sym->ident)
1086                 cur_func = sym->ident->name;
1087         __smatch_lineno = sym->pos.line;
1088         last_stmt = NULL;
1089         loop_count = 0;
1090         sm_debug("new function:  %s\n", cur_func);
1091         __slist_id = 0;
1092         if (option_two_passes) {
1093                 __unnullify_path();
1094                 loop_num = 0;
1095                 final_pass = 0;
1096                 start_function_definition(sym);
1097                 __split_stmt(base_type->stmt);
1098                 __split_stmt(base_type->inline_stmt);
1099                 nullify_path();
1100         }
1101         __unnullify_path();
1102         loop_num = 0;
1103         start_function_definition(sym);
1104         __split_stmt(base_type->stmt);
1105         __split_stmt(base_type->inline_stmt);
1106         __pass_to_client(sym, END_FUNC_HOOK);
1107         __pass_to_client(sym, AFTER_FUNC_HOOK);
1108         cur_func_sym = NULL;
1109         cur_func = NULL;
1110         clear_all_states();
1111         free_data_info_allocs();
1112         free_expression_stack(&switch_expr_stack);
1113         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1114         __bail_on_rest_of_function = 0;
1115 }
1116
1117 static void parse_inline(struct expression *call)
1118 {
1119         struct symbol *base_type;
1120         int loop_num_bak = loop_num;
1121         int final_pass_bak = final_pass;
1122         char *cur_func_bak = cur_func;
1123         struct statement_list *big_statement_stack_bak = big_statement_stack;
1124         struct expression_list *big_expression_stack_bak = big_expression_stack;
1125         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1126         struct symbol *cur_func_sym_bak = cur_func_sym;
1127
1128         __pass_to_client(call, INLINE_FN_START);
1129         final_pass = 0;  /* don't print anything */
1130         __inline_fn = call;
1131
1132         base_type = get_base_type(call->fn->symbol);
1133         cur_func_sym = call->fn->symbol;
1134         if (call->fn->symbol->ident)
1135                 cur_func = call->fn->symbol->ident->name;
1136         else
1137                 cur_func = NULL;
1138         set_position(call->fn->symbol->pos);
1139
1140         save_all_states();
1141         nullify_all_states();
1142         big_statement_stack = NULL;
1143         big_expression_stack = NULL;
1144         switch_expr_stack = NULL;
1145
1146         sm_debug("inline function:  %s\n", cur_func);
1147         __unnullify_path();
1148         loop_num = 0;
1149         start_function_definition(call->fn->symbol);
1150         __split_stmt(base_type->stmt);
1151         __split_stmt(base_type->inline_stmt);
1152         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1153         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1154
1155         free_expression_stack(&switch_expr_stack);
1156         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1157         nullify_path();
1158
1159         loop_num = loop_num_bak;
1160         final_pass = final_pass_bak;
1161         cur_func_sym = cur_func_sym_bak;
1162         cur_func = cur_func_bak;
1163         big_statement_stack = big_statement_stack_bak;
1164         big_expression_stack = big_expression_stack_bak;
1165         switch_expr_stack = switch_expr_stack_bak;
1166
1167         restore_all_states();
1168         set_position(call->pos);
1169         __inline_fn = NULL;
1170         __pass_to_client(call, INLINE_FN_END);
1171 }
1172
1173 static struct symbol_list *inlines_called;
1174 static void add_inline_function(struct symbol *sym)
1175 {
1176         static struct symbol_list *already_added;
1177         struct symbol *tmp;
1178
1179         FOR_EACH_PTR(already_added, tmp) {
1180                 if (tmp == sym)
1181                         return;
1182         } END_FOR_EACH_PTR(tmp);
1183
1184         add_ptr_list(&already_added, sym);
1185         add_ptr_list(&inlines_called, sym);
1186 }
1187
1188 static void process_inlines()
1189 {
1190         struct symbol *tmp;
1191
1192         FOR_EACH_PTR(inlines_called, tmp) {
1193                 split_function(tmp);
1194         } END_FOR_EACH_PTR(tmp);
1195         free_ptr_list(&inlines_called);
1196 }
1197
1198 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1199 {
1200         struct symbol *sym;
1201
1202         FOR_EACH_PTR_REVERSE(big_list, sym) {
1203                 if (!sym->scope)
1204                         continue;
1205                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1206                         return sym;
1207                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1208                         return sym;
1209         } END_FOR_EACH_PTR_REVERSE(sym);
1210
1211         return NULL;
1212 }
1213
1214 static void split_inlines_in_scope(struct symbol *sym)
1215 {
1216         struct symbol *base;
1217         struct symbol_list *scope_list;
1218         int stream;
1219
1220         scope_list = sym->scope->symbols;
1221         stream = sym->pos.stream;
1222
1223         /* find the last static symbol in the file */
1224         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1225                 if (sym->pos.stream != stream)
1226                         continue;
1227                 if (sym->type != SYM_NODE)
1228                         continue;
1229                 base = get_base_type(sym);
1230                 if (!base)
1231                         continue;
1232                 if (base->type != SYM_FN)
1233                         continue;
1234                 if (!base->inline_stmt)
1235                         continue;
1236                 add_inline_function(sym);
1237         } END_FOR_EACH_PTR_REVERSE(sym);
1238
1239         process_inlines();
1240 }
1241
1242 static void split_inlines(struct symbol_list *sym_list)
1243 {
1244         struct symbol *sym;
1245
1246         sym = get_last_scoped_symbol(sym_list, 0);
1247         if (sym)
1248                 split_inlines_in_scope(sym);
1249         sym = get_last_scoped_symbol(sym_list, 1);
1250         if (sym)
1251                 split_inlines_in_scope(sym);
1252 }
1253
1254 static void split_functions(struct symbol_list *sym_list)
1255 {
1256         struct symbol *sym;
1257
1258         FOR_EACH_PTR(sym_list, sym) {
1259                 set_position(sym->pos);
1260                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1261                         split_function(sym);
1262                         process_inlines();
1263                 } else {
1264                         __pass_to_client(sym, BASE_HOOK);
1265                         fake_global_assign(sym);
1266                 }
1267         } END_FOR_EACH_PTR(sym);
1268         split_inlines(sym_list);
1269         __pass_to_client(sym_list, END_FILE_HOOK);
1270 }
1271
1272 void smatch(int argc, char **argv)
1273 {
1274
1275         struct string_list *filelist = NULL;
1276         struct symbol_list *sym_list;
1277
1278         if (argc < 2) {
1279                 printf("Usage:  smatch [--debug] <filename.c>\n");
1280                 exit(1);
1281         }
1282         sparse_initialize(argc, argv, &filelist);
1283         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1284                 if (option_file_output) {
1285                         char buf[256];
1286
1287                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1288                         sm_outfd = fopen(buf, "w");
1289                         if (!sm_outfd) {
1290                                 printf("Error:  Cannot open %s\n", base_file);
1291                                 exit(1);
1292                         }
1293                 }
1294                 sym_list = sparse_keep_tokens(base_file);
1295                 split_functions(sym_list);
1296         } END_FOR_EACH_PTR_NOTAG(base_file);
1297 }