smatch_flow.c

   1 /*
   2  * Copyright (C) 2006,2008 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #define _GNU_SOURCE 1
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include "token.h"
  22 #include "scope.h"
  23 #include "smatch.h"
  24 #include "smatch_expression_stacks.h"
  25 #include "smatch_extra.h"
  26 #include "smatch_slist.h"
  27
  28 int __in_fake_assign;
  29 int final_pass;
  30 int __inline_call;
  31 struct expression  *__inline_fn;
  32
  33 static int __smatch_lineno = 0;
  34
  35 static char *base_file;
  36 static const char *filename;
  37 static char *pathname;
  38 static char *full_filename;
  39 static char *cur_func;
  40 static unsigned int loop_count;
  41 static int last_goto_statement_handled;
  42 int __expr_stmt_count;
  43 int __in_function_def;
  44 static struct expression_list *switch_expr_stack = NULL;
  45 static struct expression_list *post_op_stack = NULL;
  46
  47 struct expression_list *big_expression_stack;
  48 struct statement_list *big_statement_stack;
  49 int __in_pre_condition = 0;
  50 int __bail_on_rest_of_function = 0;
  51 static struct timeval fn_start_time;
  52 char *get_function(void) { return cur_func; }
  53 int get_lineno(void) { return __smatch_lineno; }
  54 int inside_loop(void) { return !!loop_count; }
  55 int definitely_inside_loop(void) { return !!(loop_count & ~0x80000000); }
  56 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
  57 int in_expression_statement(void) { return !!__expr_stmt_count; }
  58
  59 static void split_symlist(struct symbol_list *sym_list);
  60 static void split_declaration(struct symbol_list *sym_list);
  61 static void split_expr_list(struct expression_list *expr_list);
  62 static void add_inline_function(struct symbol *sym);
  63 static void parse_inline(struct expression *expr);
  64
  65 int option_assume_loops = 0;
  66 int option_known_conditions = 0;
  67 int option_two_passes = 0;
  68 struct symbol *cur_func_sym = NULL;
  69 struct stree *global_states;
  70
  71 int outside_of_function(void)
  72 {
  73         return cur_func_sym == NULL;
  74 }
  75
  76 const char *get_filename(void)
  77 {
  78         if (option_info)
  79                 return base_file;
  80         if (option_full_path)
  81                 return full_filename;
  82         return filename;
  83 }
  84
  85 const char *get_base_file(void)
  86 {
  87         return base_file;
  88 }
  89
  90 static void set_position(struct position pos)
  91 {
  92         int len;
  93         static int prev_stream = -1;
  94
  95         if (pos.stream == 0 && pos.line == 0)
  96                 return;
  97
  98         __smatch_lineno = pos.line;
  99
 100         if (pos.stream == prev_stream)
 101                 return;
 102
 103         filename = stream_name(pos.stream);
 104
 105         free(full_filename);
 106         pathname = getcwd(NULL, 0);
 107         if (pathname) {
 108                 len = strlen(pathname) + 1 + strlen(filename) + 1;
 109                 full_filename = malloc(len);
 110                 snprintf(full_filename, len, "%s/%s", pathname, filename);
 111         } else {
 112                 full_filename = alloc_string(filename);
 113         }
 114         free(pathname);
 115 }
 116
 117 static int is_inline_func(struct expression *expr)
 118 {
 119         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 120                 return 0;
 121         if (expr->symbol->ctype.modifiers & MOD_INLINE)
 122                 return 1;
 123         return 0;
 124 }
 125
 126 static int is_noreturn_func(struct expression *expr)
 127 {
 128         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 129                 return 0;
 130         if (expr->symbol->ctype.modifiers & MOD_NORETURN)
 131                 return 1;
 132         return 0;
 133 }
 134
 135 int inlinable(struct expression *expr)
 136 {
 137         struct symbol *sym;
 138
 139         if (__inline_fn)  /* don't nest */
 140                 return 0;
 141
 142         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 143                 return 0;
 144         if (is_no_inline_function(expr->symbol->ident->name))
 145                 return 0;
 146         sym = get_base_type(expr->symbol);
 147         if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
 148                 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
 149                         return 1;
 150                 return 0;
 151         }
 152         if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
 153                 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
 154                         return 1;
 155                 return 0;
 156         }
 157         return 0;
 158 }
 159
 160 void __process_post_op_stack(void)
 161 {
 162         struct expression *expr;
 163
 164         FOR_EACH_PTR(post_op_stack, expr) {
 165                 __pass_to_client(expr, OP_HOOK);
 166         } END_FOR_EACH_PTR(expr);
 167
 168         __free_ptr_list((struct ptr_list **)&post_op_stack);
 169 }
 170
 171 void __split_expr(struct expression *expr)
 172 {
 173         if (!expr)
 174                 return;
 175
 176         // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
 177
 178         if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
 179                 return;
 180         if (__in_fake_assign >= 4)  /* don't allow too much nesting */
 181                 return;
 182
 183         push_expression(&big_expression_stack, expr);
 184         set_position(expr->pos);
 185         __pass_to_client(expr, EXPR_HOOK);
 186
 187         switch (expr->type) {
 188         case EXPR_PREOP:
 189                 if (expr->op == '*')
 190                         __pass_to_client(expr, DEREF_HOOK);
 191                 __split_expr(expr->unop);
 192                 __pass_to_client(expr, OP_HOOK);
 193                 break;
 194         case EXPR_POSTOP:
 195                 __split_expr(expr->unop);
 196                 push_expression(&post_op_stack, expr);
 197                 break;
 198         case EXPR_STATEMENT:
 199                 __expr_stmt_count++;
 200                 __split_stmt(expr->statement);
 201                 __expr_stmt_count--;
 202                 break;
 203         case EXPR_LOGICAL:
 204         case EXPR_COMPARE:
 205                 __pass_to_client(expr, LOGIC_HOOK);
 206                 __handle_logic(expr);
 207                 break;
 208         case EXPR_BINOP:
 209                 __pass_to_client(expr, BINOP_HOOK);
 210         case EXPR_COMMA:
 211                 __split_expr(expr->left);
 212                 __process_post_op_stack();
 213                 __split_expr(expr->right);
 214                 break;
 215         case EXPR_ASSIGNMENT: {
 216                 struct expression *tmp;
 217
 218                 if (!expr->right)
 219                         break;
 220
 221                 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
 222
 223                 /* foo = !bar() */
 224                 if (__handle_condition_assigns(expr))
 225                         break;
 226                 /* foo = (x < 5 ? foo : 5); */
 227                 if (__handle_select_assigns(expr))
 228                         break;
 229                 /* foo = ({frob(); frob(); frob(); 1;}) */
 230                 if (__handle_expr_statement_assigns(expr))
 231                         break;
 232
 233                 __split_expr(expr->right);
 234                 if (outside_of_function())
 235                         __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
 236                 else
 237                         __pass_to_client(expr, ASSIGNMENT_HOOK);
 238
 239                 __fake_struct_member_assignments(expr);
 240
 241                 tmp = strip_expr(expr->right);
 242                 if (tmp->type == EXPR_CALL)
 243                         __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
 244                 if (get_macro_name(tmp->pos) &&
 245                     get_macro_name(expr->pos) != get_macro_name(tmp->pos))
 246                         __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
 247                 __split_expr(expr->left);
 248                 break;
 249         }
 250         case EXPR_DEREF:
 251                 __pass_to_client(expr, DEREF_HOOK);
 252                 __split_expr(expr->deref);
 253                 break;
 254         case EXPR_SLICE:
 255                 __split_expr(expr->base);
 256                 break;
 257         case EXPR_CAST:
 258         case EXPR_FORCE_CAST:
 259                 __pass_to_client(expr, CAST_HOOK);
 260                 __split_expr(expr->cast_expression);
 261                 break;
 262         case EXPR_SIZEOF:
 263                 if (expr->cast_expression)
 264                         __pass_to_client(strip_parens(expr->cast_expression),
 265                                          SIZEOF_HOOK);
 266                 break;
 267         case EXPR_OFFSETOF:
 268         case EXPR_ALIGNOF:
 269                 evaluate_expression(expr);
 270                 break;
 271         case EXPR_CONDITIONAL:
 272         case EXPR_SELECT:
 273                 if (known_condition_true(expr->conditional)) {
 274                         __split_expr(expr->cond_true);
 275                         break;
 276                 }
 277                 if (known_condition_false(expr->conditional)) {
 278                         __split_expr(expr->cond_false);
 279                         break;
 280                 }
 281                 __pass_to_client(expr, SELECT_HOOK);
 282                 __split_whole_condition(expr->conditional);
 283                 __split_expr(expr->cond_true);
 284                 __push_true_states();
 285                 __use_false_states();
 286                 __split_expr(expr->cond_false);
 287                 __merge_true_states();
 288                 break;
 289         case EXPR_CALL:
 290                 if (sym_name_is("__builtin_constant_p", expr->fn))
 291                         break;
 292                 split_expr_list(expr->args);
 293                 __split_expr(expr->fn);
 294                 if (is_inline_func(expr->fn))
 295                         add_inline_function(expr->fn->symbol);
 296                 if (inlinable(expr->fn))
 297                         __inline_call = 1;
 298                 __process_post_op_stack();
 299                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 300                 __inline_call = 0;
 301                 if (inlinable(expr->fn)) {
 302                         parse_inline(expr);
 303                 }
 304                 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
 305                 if (is_noreturn_func(expr->fn))
 306                         nullify_path();
 307                 break;
 308         case EXPR_INITIALIZER:
 309                 split_expr_list(expr->expr_list);
 310                 break;
 311         case EXPR_IDENTIFIER:
 312                 __split_expr(expr->ident_expression);
 313                 break;
 314         case EXPR_INDEX:
 315                 __split_expr(expr->idx_expression);
 316                 break;
 317         case EXPR_POS:
 318                 __split_expr(expr->init_expr);
 319                 break;
 320         case EXPR_SYMBOL:
 321                 __pass_to_client(expr, SYM_HOOK);
 322                 break;
 323         case EXPR_STRING:
 324                 __pass_to_client(expr, STRING_HOOK);
 325                 break;
 326         default:
 327                 break;
 328         };
 329         pop_expression(&big_expression_stack);
 330 }
 331
 332 static int is_forever_loop(struct statement *stmt)
 333 {
 334         struct expression *expr;
 335
 336         expr = strip_expr(stmt->iterator_pre_condition);
 337         if (!expr)
 338                 expr = stmt->iterator_post_condition;
 339         if (!expr) {
 340                 /* this is a for(;;) loop... */
 341                 return 1;
 342         }
 343
 344         if (expr->type == EXPR_VALUE && expr->value == 1)
 345                 return 1;
 346
 347         return 0;
 348 }
 349
 350 static int loop_num;
 351 static char *get_loop_name(int num)
 352 {
 353         char buf[256];
 354
 355         snprintf(buf, 255, "-loop%d", num);
 356         buf[255] = '\0';
 357         return alloc_sname(buf);
 358 }
 359
 360 /*
 361  * Pre Loops are while and for loops.
 362  */
 363 static void handle_pre_loop(struct statement *stmt)
 364 {
 365         int once_through; /* we go through the loop at least once */
 366         struct sm_state *extra_sm = NULL;
 367         int unchanged = 0;
 368         char *loop_name;
 369         struct stree *stree = NULL;
 370         struct sm_state *sm = NULL;
 371
 372         loop_name = get_loop_name(loop_num);
 373         loop_num++;
 374
 375         __split_stmt(stmt->iterator_pre_statement);
 376
 377         once_through = implied_condition_true(stmt->iterator_pre_condition);
 378
 379         loop_count++;
 380         __push_continues();
 381         __push_breaks();
 382
 383         __merge_gotos(loop_name);
 384
 385         extra_sm = __extra_handle_canonical_loops(stmt, &stree);
 386         __in_pre_condition++;
 387         __pass_to_client(stmt, PRELOOP_HOOK);
 388         __split_whole_condition(stmt->iterator_pre_condition);
 389         __in_pre_condition--;
 390         FOR_EACH_SM(stree, sm) {
 391                 set_state(sm->owner, sm->name, sm->sym, sm->state);
 392         } END_FOR_EACH_SM(sm);
 393         free_stree(&stree);
 394         if (extra_sm)
 395                 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
 396
 397         if (option_assume_loops)
 398                 once_through = 1;
 399
 400         __split_stmt(stmt->iterator_statement);
 401         __warn_on_silly_pre_loops();
 402         if (is_forever_loop(stmt)) {
 403                 __merge_continues();
 404                 __save_gotos(loop_name);
 405
 406                 __push_fake_cur_stree();
 407                 __split_stmt(stmt->iterator_post_statement);
 408                 stree = __pop_fake_cur_stree();
 409
 410                 __discard_false_states();
 411                 __use_breaks();
 412
 413                 if (!__path_is_null())
 414                         __merge_stree_into_cur(stree);
 415                 free_stree(&stree);
 416         } else {
 417                 __merge_continues();
 418                 unchanged = __iterator_unchanged(extra_sm);
 419                 __split_stmt(stmt->iterator_post_statement);
 420                 __save_gotos(loop_name);
 421                 __in_pre_condition++;
 422                 __split_whole_condition(stmt->iterator_pre_condition);
 423                 __in_pre_condition--;
 424                 nullify_path();
 425                 __merge_false_states();
 426                 if (once_through)
 427                         __discard_false_states();
 428                 else
 429                         __merge_false_states();
 430
 431                 if (extra_sm && unchanged)
 432                         __extra_pre_loop_hook_after(extra_sm,
 433                                                 stmt->iterator_post_statement,
 434                                                 stmt->iterator_pre_condition);
 435                 __merge_breaks();
 436         }
 437         loop_count--;
 438 }
 439
 440 /*
 441  * Post loops are do {} while();
 442  */
 443 static void handle_post_loop(struct statement *stmt)
 444 {
 445         char *loop_name;
 446
 447         loop_name = get_loop_name(loop_num);
 448         loop_num++;
 449         loop_count++;
 450
 451         __push_continues();
 452         __push_breaks();
 453         __merge_gotos(loop_name);
 454         __split_stmt(stmt->iterator_statement);
 455         __merge_continues();
 456         if (!is_zero(stmt->iterator_post_condition))
 457                 __save_gotos(loop_name);
 458
 459         if (is_forever_loop(stmt)) {
 460                 __use_breaks();
 461         } else {
 462                 __split_whole_condition(stmt->iterator_post_condition);
 463                 __use_false_states();
 464                 __merge_breaks();
 465         }
 466         loop_count--;
 467 }
 468
 469 static int empty_statement(struct statement *stmt)
 470 {
 471         if (!stmt)
 472                 return 0;
 473         if (stmt->type == STMT_EXPRESSION && !stmt->expression)
 474                 return 1;
 475         return 0;
 476 }
 477
 478 static int last_stmt_on_same_line(void)
 479 {
 480         struct statement *stmt;
 481         int i = 0;
 482
 483         FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
 484                 if (!i++)
 485                         continue;
 486                 if  (stmt->pos.line == get_lineno())
 487                         return 1;
 488                 return 0;
 489         } END_FOR_EACH_PTR_REVERSE(stmt);
 490         return 0;
 491 }
 492
 493 static void split_asm_constraints(struct expression_list *expr_list)
 494 {
 495         struct expression *expr;
 496         int state = 0;
 497
 498         FOR_EACH_PTR(expr_list, expr) {
 499                 switch (state) {
 500                 case 0: /* identifier */
 501                 case 1: /* constraint */
 502                         state++;
 503                         continue;
 504                 case 2: /* expression */
 505                         state = 0;
 506                         __split_expr(expr);
 507                         continue;
 508                 }
 509         } END_FOR_EACH_PTR(expr);
 510 }
 511
 512 static int is_case_val(struct statement *stmt, sval_t sval)
 513 {
 514         sval_t case_sval;
 515
 516         if (stmt->type != STMT_CASE)
 517                 return 0;
 518         if (!stmt->case_expression) {
 519                 __set_default();
 520                 return 1;
 521         }
 522         if (!get_value(stmt->case_expression, &case_sval))
 523                 return 0;
 524         if (case_sval.value == sval.value)
 525                 return 1;
 526         return 0;
 527 }
 528
 529 static void split_known_switch(struct statement *stmt, sval_t sval)
 530 {
 531         struct statement *tmp;
 532
 533         __split_expr(stmt->switch_expression);
 534
 535         push_expression(&switch_expr_stack, stmt->switch_expression);
 536         __save_switch_states(top_expression(switch_expr_stack));
 537         nullify_path();
 538         __push_default();
 539         __push_breaks();
 540
 541         stmt = stmt->switch_statement;
 542
 543         __push_scope_hooks();
 544         FOR_EACH_PTR(stmt->stmts, tmp) {
 545                 __smatch_lineno = tmp->pos.line;
 546                 if (is_case_val(tmp, sval)) {
 547                         __merge_switches(top_expression(switch_expr_stack),
 548                                          stmt->case_expression);
 549                         __pass_case_to_client(top_expression(switch_expr_stack),
 550                                               stmt->case_expression);
 551                 }
 552                 if (__path_is_null())
 553                         continue;
 554                 __split_stmt(tmp);
 555                 if (__path_is_null()) {
 556                         __set_default();
 557                         goto out;
 558                 }
 559         } END_FOR_EACH_PTR(tmp);
 560 out:
 561         __call_scope_hooks();
 562         if (!__pop_default())
 563                 __merge_switches(top_expression(switch_expr_stack),
 564                                  NULL);
 565         __discard_switches();
 566         __merge_breaks();
 567         pop_expression(&switch_expr_stack);
 568 }
 569
 570 static int taking_too_long(void)
 571 {
 572         int ms;
 573
 574         ms = ms_since(&fn_start_time);
 575         if (ms > 1000 * 60 * 5)  /* five minutes */
 576                 return 1;
 577         return 0;
 578 }
 579
 580 static int is_last_stmt(struct statement *cur_stmt)
 581 {
 582         struct symbol *fn = get_base_type(cur_func_sym);
 583         struct statement *stmt;
 584
 585         if (!fn)
 586                 return 0;
 587         stmt = fn->stmt;
 588         if (!stmt)
 589                 stmt = fn->inline_stmt;
 590         if (!stmt || stmt->type != STMT_COMPOUND)
 591                 return 0;
 592         stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 593         if (stmt && stmt->type == STMT_LABEL)
 594                 stmt = stmt->label_statement;
 595         if (stmt == cur_stmt)
 596                 return 1;
 597         return 0;
 598 }
 599
 600 static void handle_backward_goto(struct statement *goto_stmt)
 601 {
 602         const char *goto_name, *label_name;
 603         struct statement *func_stmt;
 604         struct symbol *base_type = get_base_type(cur_func_sym);
 605         struct statement *tmp;
 606         int found = 0;
 607
 608         if (!option_info)
 609                 return;
 610         if (last_goto_statement_handled)
 611                 return;
 612         last_goto_statement_handled = 1;
 613
 614         if (!goto_stmt->goto_label ||
 615             goto_stmt->goto_label->type != SYM_LABEL ||
 616             !goto_stmt->goto_label->ident)
 617                 return;
 618         goto_name = goto_stmt->goto_label->ident->name;
 619
 620         func_stmt = base_type->stmt;
 621         if (!func_stmt)
 622                 func_stmt = base_type->inline_stmt;
 623         if (!func_stmt)
 624                 return;
 625         if (func_stmt->type != STMT_COMPOUND)
 626                 return;
 627
 628         FOR_EACH_PTR(func_stmt->stmts, tmp) {
 629                 if (!found) {
 630                         if (tmp->type != STMT_LABEL)
 631                                 continue;
 632                         if (!tmp->label_identifier ||
 633                             tmp->label_identifier->type != SYM_LABEL ||
 634                             !tmp->label_identifier->ident)
 635                                 continue;
 636                         label_name = tmp->label_identifier->ident->name;
 637                         if (strcmp(goto_name, label_name) != 0)
 638                                 continue;
 639                         found = 1;
 640                 }
 641                 __split_stmt(tmp);
 642         } END_FOR_EACH_PTR(tmp);
 643 }
 644
 645 void __split_stmt(struct statement *stmt)
 646 {
 647         sval_t sval;
 648
 649         if (!stmt)
 650                 goto out;
 651
 652         if (__bail_on_rest_of_function || out_of_memory() || taking_too_long()) {
 653                 static char *printed = NULL;
 654
 655                 __bail_on_rest_of_function = 1;
 656                 if (printed != cur_func)
 657                         sm_msg("Function too hairy.  Giving up.");
 658                 final_pass = 0;  /* turn off sm_msg() from here */
 659                 printed = cur_func;
 660                 return;
 661         }
 662
 663         add_ptr_list(&big_statement_stack, stmt);
 664         free_expression_stack(&big_expression_stack);
 665         set_position(stmt->pos);
 666         __pass_to_client(stmt, STMT_HOOK);
 667
 668         switch (stmt->type) {
 669         case STMT_DECLARATION:
 670                 split_declaration(stmt->declaration);
 671                 break;
 672         case STMT_RETURN:
 673                 __split_expr(stmt->ret_value);
 674                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 675                 __process_post_op_stack();
 676                 nullify_path();
 677                 break;
 678         case STMT_EXPRESSION:
 679                 __split_expr(stmt->expression);
 680                 break;
 681         case STMT_COMPOUND: {
 682                 struct statement *tmp;
 683
 684                 __push_scope_hooks();
 685                 FOR_EACH_PTR(stmt->stmts, tmp) {
 686                         __split_stmt(tmp);
 687                 } END_FOR_EACH_PTR(tmp);
 688                 __call_scope_hooks();
 689                 break;
 690         }
 691         case STMT_IF:
 692                 if (known_condition_true(stmt->if_conditional)) {
 693                         __split_stmt(stmt->if_true);
 694                         break;
 695                 }
 696                 if (known_condition_false(stmt->if_conditional)) {
 697                         __split_stmt(stmt->if_false);
 698                         break;
 699                 }
 700                 if (option_known_conditions &&
 701                     implied_condition_true(stmt->if_conditional)) {
 702                         sm_info("this condition is true.");
 703                         __split_stmt(stmt->if_true);
 704                         break;
 705                 }
 706                 if (option_known_conditions &&
 707                     implied_condition_false(stmt->if_conditional)) {
 708                         sm_info("this condition is false.");
 709                         __split_stmt(stmt->if_false);
 710                         break;
 711                 }
 712                 __split_whole_condition(stmt->if_conditional);
 713                 __split_stmt(stmt->if_true);
 714                 if (empty_statement(stmt->if_true) &&
 715                         last_stmt_on_same_line() &&
 716                         !get_macro_name(stmt->if_true->pos))
 717                         sm_msg("warn: if();");
 718                 __push_true_states();
 719                 __use_false_states();
 720                 __split_stmt(stmt->if_false);
 721                 __merge_true_states();
 722                 break;
 723         case STMT_ITERATOR:
 724                 if (stmt->iterator_pre_condition)
 725                         handle_pre_loop(stmt);
 726                 else if (stmt->iterator_post_condition)
 727                         handle_post_loop(stmt);
 728                 else {
 729                         // these are for(;;) type loops.
 730                         handle_pre_loop(stmt);
 731                 }
 732                 break;
 733         case STMT_SWITCH:
 734                 if (get_value(stmt->switch_expression, &sval)) {
 735                         split_known_switch(stmt, sval);
 736                         break;
 737                 }
 738                 __split_expr(stmt->switch_expression);
 739                 push_expression(&switch_expr_stack, stmt->switch_expression);
 740                 __save_switch_states(top_expression(switch_expr_stack));
 741                 nullify_path();
 742                 __push_default();
 743                 __push_breaks();
 744                 __split_stmt(stmt->switch_statement);
 745                 if (!__pop_default())
 746                         __merge_switches(top_expression(switch_expr_stack),
 747                                       NULL);
 748                 __discard_switches();
 749                 __merge_breaks();
 750                 pop_expression(&switch_expr_stack);
 751                 break;
 752         case STMT_CASE:
 753                 __merge_switches(top_expression(switch_expr_stack),
 754                                       stmt->case_expression);
 755                 __pass_case_to_client(top_expression(switch_expr_stack),
 756                                       stmt->case_expression);
 757                 if (!stmt->case_expression)
 758                         __set_default();
 759                 __split_expr(stmt->case_expression);
 760                 __split_expr(stmt->case_to);
 761                 __split_stmt(stmt->case_statement);
 762                 break;
 763         case STMT_LABEL:
 764                 if (stmt->label_identifier &&
 765                     stmt->label_identifier->type == SYM_LABEL &&
 766                     stmt->label_identifier->ident) {
 767                         loop_count |= 0x80000000;
 768                         __merge_gotos(stmt->label_identifier->ident->name);
 769                 }
 770                 __split_stmt(stmt->label_statement);
 771                 break;
 772         case STMT_GOTO:
 773                 __split_expr(stmt->goto_expression);
 774                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 775                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 776                                 __process_breaks();
 777                         } else if (!strcmp(stmt->goto_label->ident->name,
 778                                            "continue")) {
 779                                 __process_continues();
 780                         }
 781                 } else if (stmt->goto_label &&
 782                            stmt->goto_label->type == SYM_LABEL &&
 783                            stmt->goto_label->ident) {
 784                         __save_gotos(stmt->goto_label->ident->name);
 785                 }
 786                 nullify_path();
 787                 if (is_last_stmt(stmt))
 788                         handle_backward_goto(stmt);
 789                 break;
 790         case STMT_NONE:
 791                 break;
 792         case STMT_ASM:
 793                 __pass_to_client(stmt, ASM_HOOK);
 794                 __split_expr(stmt->asm_string);
 795                 split_asm_constraints(stmt->asm_outputs);
 796                 split_asm_constraints(stmt->asm_inputs);
 797                 split_asm_constraints(stmt->asm_clobbers);
 798                 break;
 799         case STMT_CONTEXT:
 800                 break;
 801         case STMT_RANGE:
 802                 __split_expr(stmt->range_expression);
 803                 __split_expr(stmt->range_low);
 804                 __split_expr(stmt->range_high);
 805                 break;
 806         }
 807         __pass_to_client(stmt, STMT_HOOK_AFTER);
 808 out:
 809         __process_post_op_stack();
 810 }
 811
 812 static void split_expr_list(struct expression_list *expr_list)
 813 {
 814         struct expression *expr;
 815
 816         FOR_EACH_PTR(expr_list, expr) {
 817                 __split_expr(expr);
 818                 __process_post_op_stack();
 819         } END_FOR_EACH_PTR(expr);
 820 }
 821
 822 static void split_sym(struct symbol *sym)
 823 {
 824         if (!sym)
 825                 return;
 826         if (!(sym->namespace & NS_SYMBOL))
 827                 return;
 828
 829         __split_stmt(sym->stmt);
 830         __split_expr(sym->array_size);
 831         split_symlist(sym->arguments);
 832         split_symlist(sym->symbol_list);
 833         __split_stmt(sym->inline_stmt);
 834         split_symlist(sym->inline_symbol_list);
 835 }
 836
 837 static void split_symlist(struct symbol_list *sym_list)
 838 {
 839         struct symbol *sym;
 840
 841         FOR_EACH_PTR(sym_list, sym) {
 842                 split_sym(sym);
 843         } END_FOR_EACH_PTR(sym);
 844 }
 845
 846 typedef void (fake_cb)(struct expression *expr);
 847
 848 static int member_to_number(struct expression *expr, struct ident *member)
 849 {
 850         struct symbol *type, *tmp;
 851         char *name;
 852         int i;
 853
 854         if (!member)
 855                 return -1;
 856         name = member->name;
 857
 858         type = get_type(expr);
 859         if (!type || type->type != SYM_STRUCT)
 860                 return -1;
 861
 862         i = -1;
 863         FOR_EACH_PTR(type->symbol_list, tmp) {
 864                 i++;
 865                 if (!tmp->ident)
 866                         continue;
 867                 if (strcmp(name, tmp->ident->name) == 0)
 868                         return i;
 869         } END_FOR_EACH_PTR(tmp);
 870         return -1;
 871 }
 872
 873 static struct ident *number_to_member(struct expression *expr, int num)
 874 {
 875         struct symbol *type, *member;
 876         int i = 0;
 877
 878         type = get_type(expr);
 879         if (!type || type->type != SYM_STRUCT)
 880                 return NULL;
 881
 882         FOR_EACH_PTR(type->symbol_list, member) {
 883                 if (i == num)
 884                         return member->ident;
 885                 i++;
 886         } END_FOR_EACH_PTR(member);
 887         return NULL;
 888 }
 889
 890 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 891
 892 struct member_set {
 893         struct ident *ident;
 894         int set;
 895 };
 896
 897 static struct member_set *alloc_member_set(struct symbol *type)
 898 {
 899         struct member_set *member_set;
 900         struct symbol *member;
 901         int member_count;
 902         int member_idx;
 903
 904         member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 905         member_set = malloc(member_count * sizeof(*member_set));
 906         member_idx = 0;
 907         FOR_EACH_PTR(type->symbol_list, member) {
 908                 member_set[member_idx].ident = member->ident;
 909                 member_set[member_idx].set = 0;
 910                 member_idx++;
 911         } END_FOR_EACH_PTR(member);
 912
 913         return member_set;
 914 }
 915
 916 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
 917 {
 918         int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 919         int i;
 920
 921         for (i = 0; i < member_count; i++) {
 922                 if (member_set[i].ident == ident) {
 923                         member_set[i].set = 1;
 924                         return;
 925                 }
 926         }
 927 //      crap.  this is buggy.
 928 //      sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
 929 }
 930
 931 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
 932 {
 933         struct expression *deref, *assign;
 934         struct symbol *member, *member_type;
 935         int member_idx;
 936
 937         member_idx = 0;
 938         FOR_EACH_PTR(type->symbol_list, member) {
 939                 if (!member->ident || member_set[member_idx].set) {
 940                         member_idx++;
 941                         continue;
 942                 }
 943                 member_type = get_real_base_type(member);
 944                 if (!member_type || member_type->type == SYM_ARRAY) {
 945                         member_idx++;
 946                         continue;
 947                 }
 948                 /* TODO: this should be handled recursively and not ignored */
 949                 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION) {
 950                         member_idx++;
 951                         continue;
 952                 }
 953                 deref = member_expression(symbol, '.', member->ident);
 954                 assign = assign_expression(deref, zero_expr());
 955                 __split_expr(assign);
 956                 member_idx++;
 957         } END_FOR_EACH_PTR(member);
 958
 959 }
 960
 961 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 962 {
 963         struct expression *deref, *assign, *tmp;
 964         struct symbol *struct_type, *type;
 965         struct ident *member;
 966         int member_idx;
 967         struct member_set *member_set;
 968
 969         struct_type = get_type(symbol);
 970         if (!struct_type ||
 971             (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
 972                 return;
 973
 974         member_set = alloc_member_set(struct_type);
 975
 976         member_idx = 0;
 977         FOR_EACH_PTR(members, tmp) {
 978                 member = number_to_member(symbol, member_idx);
 979                 while (tmp->type == EXPR_IDENTIFIER) {
 980                         member = tmp->expr_ident;
 981                         member_idx = member_to_number(symbol, member);
 982                         tmp = tmp->ident_expression;
 983                 }
 984                 mark_member_as_set(struct_type, member_set, member);
 985                 member_idx++;
 986                 deref = member_expression(symbol, '.', member);
 987                 if (tmp->type == EXPR_INITIALIZER) {
 988                         type = get_type(deref);
 989                         if (type && type->type == SYM_ARRAY)
 990                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 991                         else
 992                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 993                 } else {
 994                         assign = assign_expression(deref, tmp);
 995                         fake_cb(assign);
 996                 }
 997         } END_FOR_EACH_PTR(tmp);
 998
 999         set_unset_to_zero(symbol, struct_type, member_set);
1000 }
1001
1002 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
1003 {
1004         fake_member_assigns_helper(symbol_expression(sym),
1005                                    sym->initializer->expr_list, fake_cb);
1006 }
1007
1008 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
1009 {
1010         struct expression *offset, *binop, *assign, *tmp;
1011         struct symbol *type;
1012         int idx;
1013
1014         idx = 0;
1015         FOR_EACH_PTR(expr_list, tmp) {
1016                 if (tmp->type == EXPR_INDEX) {
1017                         if (tmp->idx_from != tmp->idx_to)
1018                                 return;
1019                         idx = tmp->idx_from;
1020                         if (!tmp->idx_expression)
1021                                 goto next;
1022                         tmp = tmp->idx_expression;
1023                 }
1024                 offset = value_expr(idx);
1025                 binop = array_element_expression(array, offset);
1026                 if (tmp->type == EXPR_INITIALIZER) {
1027                         type = get_type(binop);
1028                         if (type && type->type == SYM_ARRAY)
1029                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1030                         else
1031                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1032                 } else {
1033                         assign = assign_expression(binop, tmp);
1034                         fake_cb(assign);
1035                 }
1036 next:
1037                 idx++;
1038         } END_FOR_EACH_PTR(tmp);
1039 }
1040
1041 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1042 {
1043         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1044 }
1045
1046 static void fake_assign_expr(struct symbol *sym)
1047 {
1048         struct expression *assign, *symbol;
1049
1050         symbol = symbol_expression(sym);
1051         assign = assign_expression(symbol, sym->initializer);
1052         __split_expr(assign);
1053 }
1054
1055 static void call_split_expr(struct expression *expr)
1056 {
1057         __split_expr(expr);
1058 }
1059
1060 static void do_initializer_stuff(struct symbol *sym)
1061 {
1062         if (!sym->initializer)
1063                 return;
1064
1065         if (sym->initializer->type == EXPR_INITIALIZER) {
1066                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1067                         fake_element_assigns(sym, call_split_expr);
1068                 else
1069                         fake_member_assigns(sym, call_split_expr);
1070         } else {
1071                 fake_assign_expr(sym);
1072         }
1073 }
1074
1075 static void split_declaration(struct symbol_list *sym_list)
1076 {
1077         struct symbol *sym;
1078
1079         FOR_EACH_PTR(sym_list, sym) {
1080                 __pass_to_client(sym, DECLARATION_HOOK);
1081                 do_initializer_stuff(sym);
1082                 split_sym(sym);
1083         } END_FOR_EACH_PTR(sym);
1084 }
1085
1086 static void call_global_assign_hooks(struct expression *assign)
1087 {
1088         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1089 }
1090
1091 static void fake_global_assign(struct symbol *sym)
1092 {
1093         struct expression *assign, *symbol;
1094
1095         if (get_real_base_type(sym)->type == SYM_ARRAY) {
1096                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1097                         fake_element_assigns(sym, call_global_assign_hooks);
1098                 } else if (sym->initializer) {
1099                         symbol = symbol_expression(sym);
1100                         assign = assign_expression(symbol, sym->initializer);
1101                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1102                 } else {
1103                         fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1104                 }
1105         } else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1106                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1107                         fake_member_assigns(sym, call_global_assign_hooks);
1108                 } else if (sym->initializer) {
1109                         symbol = symbol_expression(sym);
1110                         assign = assign_expression(symbol, sym->initializer);
1111                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1112                 } else {
1113                         fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1114                 }
1115         } else {
1116                 symbol = symbol_expression(sym);
1117                 if (sym->initializer)
1118                         assign = assign_expression(symbol, sym->initializer);
1119                 else
1120                         assign = assign_expression(symbol, zero_expr());
1121                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1122         }
1123 }
1124
1125 static void start_function_definition(struct symbol *sym)
1126 {
1127         __in_function_def = 1;
1128         __pass_to_client(sym, FUNC_DEF_HOOK);
1129         __in_function_def = 0;
1130         __pass_to_client(sym, AFTER_DEF_HOOK);
1131
1132 }
1133
1134 static void split_function(struct symbol *sym)
1135 {
1136         struct symbol *base_type = get_base_type(sym);
1137
1138         if (!base_type->stmt && !base_type->inline_stmt)
1139                 return;
1140
1141         gettimeofday(&fn_start_time, NULL);
1142         cur_func_sym = sym;
1143         if (sym->ident)
1144                 cur_func = sym->ident->name;
1145         __smatch_lineno = sym->pos.line;
1146         loop_count = 0;
1147         last_goto_statement_handled = 0;
1148         sm_debug("new function:  %s\n", cur_func);
1149         __stree_id = 0;
1150         if (option_two_passes) {
1151                 __unnullify_path();
1152                 loop_num = 0;
1153                 final_pass = 0;
1154                 start_function_definition(sym);
1155                 __split_stmt(base_type->stmt);
1156                 __split_stmt(base_type->inline_stmt);
1157                 nullify_path();
1158         }
1159         __unnullify_path();
1160         loop_num = 0;
1161         final_pass = 1;
1162         start_function_definition(sym);
1163         __split_stmt(base_type->stmt);
1164         __split_stmt(base_type->inline_stmt);
1165         __pass_to_client(sym, END_FUNC_HOOK);
1166         __pass_to_client(sym, AFTER_FUNC_HOOK);
1167
1168         cur_func_sym = NULL;
1169         cur_func = NULL;
1170         clear_all_states();
1171         free_data_info_allocs();
1172         free_expression_stack(&switch_expr_stack);
1173         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1174         __bail_on_rest_of_function = 0;
1175 }
1176
1177 static void parse_inline(struct expression *call)
1178 {
1179         struct symbol *base_type;
1180         int loop_num_bak = loop_num;
1181         int final_pass_bak = final_pass;
1182         char *cur_func_bak = cur_func;
1183         struct statement_list *big_statement_stack_bak = big_statement_stack;
1184         struct expression_list *big_expression_stack_bak = big_expression_stack;
1185         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1186         struct symbol *cur_func_sym_bak = cur_func_sym;
1187
1188         __pass_to_client(call, INLINE_FN_START);
1189         final_pass = 0;  /* don't print anything */
1190         __inline_fn = call;
1191
1192         base_type = get_base_type(call->fn->symbol);
1193         cur_func_sym = call->fn->symbol;
1194         if (call->fn->symbol->ident)
1195                 cur_func = call->fn->symbol->ident->name;
1196         else
1197                 cur_func = NULL;
1198         set_position(call->fn->symbol->pos);
1199
1200         save_all_states();
1201         big_statement_stack = NULL;
1202         big_expression_stack = NULL;
1203         switch_expr_stack = NULL;
1204
1205         sm_debug("inline function:  %s\n", cur_func);
1206         __unnullify_path();
1207         loop_num = 0;
1208         start_function_definition(call->fn->symbol);
1209         __split_stmt(base_type->stmt);
1210         __split_stmt(base_type->inline_stmt);
1211         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1212         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1213
1214         free_expression_stack(&switch_expr_stack);
1215         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1216         nullify_path();
1217         free_goto_stack();
1218
1219         loop_num = loop_num_bak;
1220         final_pass = final_pass_bak;
1221         cur_func_sym = cur_func_sym_bak;
1222         cur_func = cur_func_bak;
1223         big_statement_stack = big_statement_stack_bak;
1224         big_expression_stack = big_expression_stack_bak;
1225         switch_expr_stack = switch_expr_stack_bak;
1226
1227         restore_all_states();
1228         set_position(call->pos);
1229         __inline_fn = NULL;
1230         __pass_to_client(call, INLINE_FN_END);
1231 }
1232
1233 static struct symbol_list *inlines_called;
1234 static void add_inline_function(struct symbol *sym)
1235 {
1236         static struct symbol_list *already_added;
1237         struct symbol *tmp;
1238
1239         FOR_EACH_PTR(already_added, tmp) {
1240                 if (tmp == sym)
1241                         return;
1242         } END_FOR_EACH_PTR(tmp);
1243
1244         add_ptr_list(&already_added, sym);
1245         add_ptr_list(&inlines_called, sym);
1246 }
1247
1248 static void process_inlines(void)
1249 {
1250         struct symbol *tmp;
1251
1252         FOR_EACH_PTR(inlines_called, tmp) {
1253                 split_function(tmp);
1254         } END_FOR_EACH_PTR(tmp);
1255         free_ptr_list(&inlines_called);
1256 }
1257
1258 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1259 {
1260         struct symbol *sym;
1261
1262         FOR_EACH_PTR_REVERSE(big_list, sym) {
1263                 if (!sym->scope)
1264                         continue;
1265                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1266                         return sym;
1267                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1268                         return sym;
1269         } END_FOR_EACH_PTR_REVERSE(sym);
1270
1271         return NULL;
1272 }
1273
1274 static void split_inlines_in_scope(struct symbol *sym)
1275 {
1276         struct symbol *base;
1277         struct symbol_list *scope_list;
1278         int stream;
1279
1280         scope_list = sym->scope->symbols;
1281         stream = sym->pos.stream;
1282
1283         /* find the last static symbol in the file */
1284         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1285                 if (sym->pos.stream != stream)
1286                         continue;
1287                 if (sym->type != SYM_NODE)
1288                         continue;
1289                 base = get_base_type(sym);
1290                 if (!base)
1291                         continue;
1292                 if (base->type != SYM_FN)
1293                         continue;
1294                 if (!base->inline_stmt)
1295                         continue;
1296                 add_inline_function(sym);
1297         } END_FOR_EACH_PTR_REVERSE(sym);
1298
1299         process_inlines();
1300 }
1301
1302 static void split_inlines(struct symbol_list *sym_list)
1303 {
1304         struct symbol *sym;
1305
1306         sym = get_last_scoped_symbol(sym_list, 0);
1307         if (sym)
1308                 split_inlines_in_scope(sym);
1309         sym = get_last_scoped_symbol(sym_list, 1);
1310         if (sym)
1311                 split_inlines_in_scope(sym);
1312 }
1313
1314 static struct stree *clone_estates_perm(struct stree *orig)
1315 {
1316         struct stree *ret = NULL;
1317         struct sm_state *tmp;
1318
1319         FOR_EACH_SM(orig, tmp) {
1320                 set_state_stree_perm(&ret, tmp->owner, tmp->name, tmp->sym, clone_estate_perm(tmp->state));
1321         } END_FOR_EACH_SM(tmp);
1322
1323         return ret;
1324 }
1325
1326 static void split_functions(struct symbol_list *sym_list)
1327 {
1328         struct symbol *sym;
1329
1330         __unnullify_path();
1331         FOR_EACH_PTR(sym_list, sym) {
1332                 set_position(sym->pos);
1333                 if (sym->type != SYM_NODE || get_base_type(sym)->type != SYM_FN) {
1334                         __pass_to_client(sym, BASE_HOOK);
1335                         fake_global_assign(sym);
1336                 }
1337         } END_FOR_EACH_PTR(sym);
1338         global_states = clone_estates_perm(get_all_states_stree(SMATCH_EXTRA));
1339         nullify_path();
1340
1341         FOR_EACH_PTR(sym_list, sym) {
1342                 set_position(sym->pos);
1343                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1344                         split_function(sym);
1345                         process_inlines();
1346                 }
1347         } END_FOR_EACH_PTR(sym);
1348         split_inlines(sym_list);
1349         __pass_to_client(sym_list, END_FILE_HOOK);
1350 }
1351
1352 void smatch(int argc, char **argv)
1353 {
1354
1355         struct string_list *filelist = NULL;
1356         struct symbol_list *sym_list;
1357
1358         if (argc < 2) {
1359                 printf("Usage:  smatch [--debug] <filename.c>\n");
1360                 exit(1);
1361         }
1362         sparse_initialize(argc, argv, &filelist);
1363         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1364                 if (option_file_output) {
1365                         char buf[256];
1366
1367                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1368                         sm_outfd = fopen(buf, "w");
1369                         if (!sm_outfd) {
1370                                 printf("Error:  Cannot open %s\n", base_file);
1371                                 exit(1);
1372                         }
1373                 }
1374                 sym_list = sparse_keep_tokens(base_file);
1375                 split_functions(sym_list);
1376         } END_FOR_EACH_PTR_NOTAG(base_file);
1377 }