smatch_flow.c

   1 /*
   2  * sparse/smatch_flow.c
   3  *
   4  * Copyright (C) 2006,2008 Dan Carpenter.
   5  *
   6  *  Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #define _GNU_SOURCE 1
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include "token.h"
  14 #include "scope.h"
  15 #include "smatch.h"
  16 #include "smatch_expression_stacks.h"
  17 #include "smatch_extra.h"
  18 #include "smatch_slist.h"
  19
  20 int __in_fake_assign;
  21 int final_pass;
  22 int __inline_call;
  23 struct expression  *__inline_fn;
  24
  25 static int __smatch_lineno = 0;
  26
  27 static char *base_file;
  28 static const char *filename;
  29 static char *pathname;
  30 static char *full_filename;
  31 static char *cur_func;
  32 static unsigned int loop_count;
  33 int __expr_stmt_count;
  34 int __in_function_def;
  35 static struct expression_list *switch_expr_stack = NULL;
  36 static struct expression_list *post_op_stack = NULL;
  37
  38 struct expression_list *big_expression_stack;
  39 struct statement_list *big_statement_stack;
  40 int __in_pre_condition = 0;
  41 int __bail_on_rest_of_function = 0;
  42 char *get_function(void) { return cur_func; }
  43 int get_lineno(void) { return __smatch_lineno; }
  44 int inside_loop(void) { return !!loop_count; }
  45 int definitely_inside_loop(void) { return !!(loop_count & ~0x80000000); }
  46 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
  47 int in_expression_statement(void) { return !!__expr_stmt_count; }
  48
  49 static void split_symlist(struct symbol_list *sym_list);
  50 static void split_declaration(struct symbol_list *sym_list);
  51 static void split_expr_list(struct expression_list *expr_list);
  52 static void add_inline_function(struct symbol *sym);
  53 static void parse_inline(struct expression *expr);
  54
  55 int option_assume_loops = 0;
  56 int option_known_conditions = 0;
  57 int option_two_passes = 0;
  58 struct symbol *cur_func_sym = NULL;
  59
  60 int outside_of_function(void)
  61 {
  62         return cur_func_sym == NULL;
  63 }
  64
  65 const char *get_filename(void)
  66 {
  67         if (option_info)
  68                 return base_file;
  69         if (option_full_path)
  70                 return full_filename;
  71         return filename;
  72 }
  73
  74 const char *get_base_file(void)
  75 {
  76         return base_file;
  77 }
  78
  79 static void set_position(struct position pos)
  80 {
  81         int len;
  82         static int prev_stream = -1;
  83
  84         if (pos.stream == 0 && pos.line == 0)
  85                 return;
  86
  87         __smatch_lineno = pos.line;
  88
  89         if (pos.stream == prev_stream)
  90                 return;
  91
  92         filename = stream_name(pos.stream);
  93
  94         free(full_filename);
  95         pathname = getcwd(NULL, 0);
  96         if (pathname) {
  97                 len = strlen(pathname) + 1 + strlen(filename) + 1;
  98                 full_filename = malloc(len);
  99                 snprintf(full_filename, len, "%s/%s", pathname, filename);
 100         } else {
 101                 full_filename = alloc_string(filename);
 102         }
 103         free(pathname);
 104 }
 105
 106 static int is_inline_func(struct expression *expr)
 107 {
 108         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 109                 return 0;
 110         if (expr->symbol->ctype.modifiers & MOD_INLINE)
 111                 return 1;
 112         return 0;
 113 }
 114
 115 static int is_noreturn_func(struct expression *expr)
 116 {
 117         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 118                 return 0;
 119         if (expr->symbol->ctype.modifiers & MOD_NORETURN)
 120                 return 1;
 121         return 0;
 122 }
 123
 124 int inlinable(struct expression *expr)
 125 {
 126         struct symbol *sym;
 127
 128         if (__inline_fn)  /* don't nest */
 129                 return 0;
 130
 131         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 132                 return 0;
 133         if (is_no_inline_function(expr->symbol->ident->name))
 134                 return 0;
 135         sym = get_base_type(expr->symbol);
 136         if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
 137                 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
 138                         return 1;
 139                 return 0;
 140         }
 141         if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
 142                 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
 143                         return 1;
 144                 return 0;
 145         }
 146         return 0;
 147 }
 148
 149 void __process_post_op_stack(void)
 150 {
 151         struct expression *expr;
 152
 153         FOR_EACH_PTR(post_op_stack, expr) {
 154                 __pass_to_client(expr, OP_HOOK);
 155         } END_FOR_EACH_PTR(expr);
 156
 157         __free_ptr_list((struct ptr_list **)&post_op_stack);
 158 }
 159
 160 void __split_expr(struct expression *expr)
 161 {
 162         if (!expr)
 163                 return;
 164
 165         // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
 166
 167         if (__in_fake_assign && expr->type != EXPR_ASSIGNMENT)
 168                 return;
 169         if (__in_fake_assign >= 4)  /* don't allow too much nesting */
 170                 return;
 171
 172         push_expression(&big_expression_stack, expr);
 173         set_position(expr->pos);
 174         __pass_to_client(expr, EXPR_HOOK);
 175
 176         switch (expr->type) {
 177         case EXPR_PREOP:
 178                 if (expr->op == '*')
 179                         __pass_to_client(expr, DEREF_HOOK);
 180                 __split_expr(expr->unop);
 181                 __pass_to_client(expr, OP_HOOK);
 182                 break;
 183         case EXPR_POSTOP:
 184                 __split_expr(expr->unop);
 185                 push_expression(&post_op_stack, expr);
 186                 break;
 187         case EXPR_STATEMENT:
 188                 __expr_stmt_count++;
 189                 __split_stmt(expr->statement);
 190                 __expr_stmt_count--;
 191                 break;
 192         case EXPR_LOGICAL:
 193         case EXPR_COMPARE:
 194                 __pass_to_client(expr, LOGIC_HOOK);
 195                 __handle_logic(expr);
 196                 break;
 197         case EXPR_BINOP:
 198                 __pass_to_client(expr, BINOP_HOOK);
 199         case EXPR_COMMA:
 200                 __split_expr(expr->left);
 201                 __process_post_op_stack();
 202                 __split_expr(expr->right);
 203                 break;
 204         case EXPR_ASSIGNMENT: {
 205                 struct expression *tmp;
 206
 207                 if (!expr->right)
 208                         break;
 209
 210                 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
 211
 212                 /* foo = !bar() */
 213                 if (__handle_condition_assigns(expr))
 214                         break;
 215                 /* foo = (x < 5 ? foo : 5); */
 216                 if (__handle_select_assigns(expr))
 217                         break;
 218                 /* foo = ({frob(); frob(); frob(); 1;}) */
 219                 if (__handle_expr_statement_assigns(expr))
 220                         break;
 221
 222                 __split_expr(expr->right);
 223                 if (outside_of_function())
 224                         __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
 225                 else
 226                         __pass_to_client(expr, ASSIGNMENT_HOOK);
 227
 228                 __fake_struct_member_assignments(expr);
 229
 230                 tmp = strip_expr(expr->right);
 231                 if (tmp->type == EXPR_CALL)
 232                         __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
 233                 if (get_macro_name(tmp->pos) &&
 234                     get_macro_name(expr->pos) != get_macro_name(tmp->pos))
 235                         __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
 236                 __split_expr(expr->left);
 237                 break;
 238         }
 239         case EXPR_DEREF:
 240                 __pass_to_client(expr, DEREF_HOOK);
 241                 __split_expr(expr->deref);
 242                 break;
 243         case EXPR_SLICE:
 244                 __split_expr(expr->base);
 245                 break;
 246         case EXPR_CAST:
 247         case EXPR_FORCE_CAST:
 248                 __pass_to_client(expr, CAST_HOOK);
 249                 __split_expr(expr->cast_expression);
 250                 break;
 251         case EXPR_SIZEOF:
 252                 if (expr->cast_expression)
 253                         __pass_to_client(strip_parens(expr->cast_expression),
 254                                          SIZEOF_HOOK);
 255                 break;
 256         case EXPR_OFFSETOF:
 257         case EXPR_ALIGNOF:
 258                 evaluate_expression(expr);
 259                 break;
 260         case EXPR_CONDITIONAL:
 261         case EXPR_SELECT:
 262                 if (known_condition_true(expr->conditional)) {
 263                         __split_expr(expr->cond_true);
 264                         break;
 265                 }
 266                 if (known_condition_false(expr->conditional)) {
 267                         __split_expr(expr->cond_false);
 268                         break;
 269                 }
 270                 __pass_to_client(expr, SELECT_HOOK);
 271                 __split_whole_condition(expr->conditional);
 272                 __split_expr(expr->cond_true);
 273                 __push_true_states();
 274                 __use_false_states();
 275                 __split_expr(expr->cond_false);
 276                 __merge_true_states();
 277                 break;
 278         case EXPR_CALL:
 279                 if (sym_name_is("__builtin_constant_p", expr->fn))
 280                         break;
 281                 split_expr_list(expr->args);
 282                 __split_expr(expr->fn);
 283                 if (is_inline_func(expr->fn))
 284                         add_inline_function(expr->fn->symbol);
 285                 if (inlinable(expr->fn))
 286                         __inline_call = 1;
 287                 __process_post_op_stack();
 288                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 289                 __inline_call = 0;
 290                 if (inlinable(expr->fn)) {
 291                         parse_inline(expr);
 292                 }
 293                 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
 294                 if (is_noreturn_func(expr->fn))
 295                         nullify_path();
 296                 break;
 297         case EXPR_INITIALIZER:
 298                 split_expr_list(expr->expr_list);
 299                 break;
 300         case EXPR_IDENTIFIER:
 301                 __split_expr(expr->ident_expression);
 302                 break;
 303         case EXPR_INDEX:
 304                 __split_expr(expr->idx_expression);
 305                 break;
 306         case EXPR_POS:
 307                 __split_expr(expr->init_expr);
 308                 break;
 309         case EXPR_SYMBOL:
 310                 __pass_to_client(expr, SYM_HOOK);
 311                 break;
 312         case EXPR_STRING:
 313                 __pass_to_client(expr, STRING_HOOK);
 314                 break;
 315         default:
 316                 break;
 317         };
 318         pop_expression(&big_expression_stack);
 319 }
 320
 321 static int is_forever_loop(struct statement *stmt)
 322 {
 323         struct expression *expr;
 324
 325         expr = strip_expr(stmt->iterator_pre_condition);
 326         if (!expr)
 327                 expr = stmt->iterator_post_condition;
 328         if (!expr) {
 329                 /* this is a for(;;) loop... */
 330                 return 1;
 331         }
 332
 333         if (expr->type == EXPR_VALUE && expr->value == 1)
 334                 return 1;
 335
 336         return 0;
 337 }
 338
 339 static int loop_num;
 340 static char *get_loop_name(int num)
 341 {
 342         char buf[256];
 343
 344         snprintf(buf, 255, "-loop%d", num);
 345         buf[255] = '\0';
 346         return alloc_sname(buf);
 347 }
 348
 349 /*
 350  * Pre Loops are while and for loops.
 351  */
 352 static void handle_pre_loop(struct statement *stmt)
 353 {
 354         int once_through; /* we go through the loop at least once */
 355         struct sm_state *extra_sm = NULL;
 356         int unchanged = 0;
 357         char *loop_name;
 358         struct state_list *slist = NULL;
 359         struct sm_state *sm = NULL;
 360
 361         loop_name = get_loop_name(loop_num);
 362         loop_num++;
 363
 364         __split_stmt(stmt->iterator_pre_statement);
 365
 366         once_through = implied_condition_true(stmt->iterator_pre_condition);
 367
 368         loop_count++;
 369         __push_continues();
 370         __push_breaks();
 371
 372         __merge_gotos(loop_name);
 373
 374         extra_sm = __extra_handle_canonical_loops(stmt, &slist);
 375         __in_pre_condition++;
 376         __pass_to_client(stmt, PRELOOP_HOOK);
 377         __split_whole_condition(stmt->iterator_pre_condition);
 378         __in_pre_condition--;
 379         FOR_EACH_PTR(slist, sm) {
 380                 set_state(sm->owner, sm->name, sm->sym, sm->state);
 381         } END_FOR_EACH_PTR(sm);
 382         free_slist(&slist);
 383         if (extra_sm)
 384                 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
 385
 386         if (option_assume_loops)
 387                 once_through = 1;
 388
 389         __split_stmt(stmt->iterator_statement);
 390         __warn_on_silly_pre_loops();
 391         if (is_forever_loop(stmt)) {
 392                 struct state_list *slist;
 393
 394                 __save_gotos(loop_name);
 395
 396                 __push_fake_cur_slist();
 397                 __split_stmt(stmt->iterator_post_statement);
 398                 slist = __pop_fake_cur_slist();
 399
 400                 __discard_continues();
 401                 __discard_false_states();
 402                 __use_breaks();
 403
 404                 if (!__path_is_null())
 405                         __merge_slist_into_cur(slist);
 406                 free_slist(&slist);
 407         } else {
 408                 __merge_continues();
 409                 unchanged = __iterator_unchanged(extra_sm);
 410                 __split_stmt(stmt->iterator_post_statement);
 411                 __save_gotos(loop_name);
 412                 __split_whole_condition(stmt->iterator_pre_condition);
 413                 nullify_path();
 414                 __merge_false_states();
 415                 if (once_through)
 416                         __discard_false_states();
 417                 else
 418                         __merge_false_states();
 419
 420                 if (extra_sm && unchanged)
 421                         __extra_pre_loop_hook_after(extra_sm,
 422                                                 stmt->iterator_post_statement,
 423                                                 stmt->iterator_pre_condition);
 424                 __merge_breaks();
 425         }
 426         loop_count--;
 427 }
 428
 429 /*
 430  * Post loops are do {} while();
 431  */
 432 static void handle_post_loop(struct statement *stmt)
 433 {
 434         char *loop_name;
 435
 436         loop_name = get_loop_name(loop_num);
 437         loop_num++;
 438         loop_count++;
 439
 440         __push_continues();
 441         __push_breaks();
 442         __merge_gotos(loop_name);
 443         __split_stmt(stmt->iterator_statement);
 444         __merge_continues();
 445         if (!is_zero(stmt->iterator_post_condition))
 446                 __save_gotos(loop_name);
 447
 448         if (is_forever_loop(stmt)) {
 449                 __use_breaks();
 450         } else {
 451                 __split_whole_condition(stmt->iterator_post_condition);
 452                 __use_false_states();
 453                 __merge_breaks();
 454         }
 455         loop_count--;
 456 }
 457
 458 static int empty_statement(struct statement *stmt)
 459 {
 460         if (!stmt)
 461                 return 0;
 462         if (stmt->type == STMT_EXPRESSION && !stmt->expression)
 463                 return 1;
 464         return 0;
 465 }
 466
 467 static int last_stmt_on_same_line()
 468 {
 469         struct statement *stmt;
 470         int i = 0;
 471
 472         FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
 473                 if (!i++)
 474                         continue;
 475                 if  (stmt->pos.line == get_lineno())
 476                         return 1;
 477                 return 0;
 478         } END_FOR_EACH_PTR_REVERSE(stmt);
 479         return 0;
 480 }
 481
 482 static struct statement *last_stmt;
 483 static int is_last_stmt(struct statement *stmt)
 484 {
 485         if (stmt == last_stmt)
 486                 return 1;
 487         return 0;
 488 }
 489
 490 static void print_unreached_initializers(struct symbol_list *sym_list)
 491 {
 492         struct symbol *sym;
 493
 494         FOR_EACH_PTR(sym_list, sym) {
 495                 if (sym->initializer)
 496                         sm_msg("info: '%s' is not actually initialized (unreached code).",
 497                                 (sym->ident ? sym->ident->name : "this variable"));
 498         } END_FOR_EACH_PTR(sym);
 499 }
 500
 501 static void print_unreached(struct statement *stmt)
 502 {
 503         static int print = 1;
 504
 505         if (__inline_fn)
 506                 return;
 507
 508         if (!__path_is_null()) {
 509                 print = 1;
 510                 return;
 511         }
 512         if (!print)
 513                 return;
 514
 515         switch (stmt->type) {
 516         case STMT_COMPOUND: /* after a switch before a case stmt */
 517         case STMT_RANGE:
 518         case STMT_CASE:
 519         case STMT_LABEL:
 520                 return;
 521         case STMT_DECLARATION: /* switch (x) { int a; case foo: ... */
 522                 print_unreached_initializers(stmt->declaration);
 523                 return;
 524         case STMT_RETURN: /* gcc complains if you don't have a return statement */
 525                 if (is_last_stmt(stmt))
 526                         return;
 527                 break;
 528         case STMT_GOTO:
 529                 /* people put extra breaks inside switch statements */
 530                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE &&
 531                     strcmp(stmt->goto_label->ident->name, "break") == 0)
 532                         return;
 533                 break;
 534         default:
 535                 break;
 536         }
 537         if (empty_statement(stmt))
 538                 return;
 539         if (!option_spammy)
 540                 return;
 541         sm_msg("info: ignoring unreachable code.");
 542         print = 0;
 543 }
 544
 545 static void split_asm_constraints(struct expression_list *expr_list)
 546 {
 547         struct expression *expr;
 548         int state = 0;
 549
 550         FOR_EACH_PTR(expr_list, expr) {
 551                 switch (state) {
 552                 case 0: /* identifier */
 553                 case 1: /* constraint */
 554                         state++;
 555                         continue;
 556                 case 2: /* expression */
 557                         state = 0;
 558                         __split_expr(expr);
 559                         continue;
 560                 }
 561         } END_FOR_EACH_PTR(expr);
 562 }
 563
 564 static int is_case_val(struct statement *stmt, sval_t sval)
 565 {
 566         sval_t case_sval;
 567
 568         if (stmt->type != STMT_CASE)
 569                 return 0;
 570         if (!stmt->case_expression) {
 571                 __set_default();
 572                 return 1;
 573         }
 574         if (!get_value(stmt->case_expression, &case_sval))
 575                 return 0;
 576         if (case_sval.value == sval.value)
 577                 return 1;
 578         return 0;
 579 }
 580
 581 static void split_known_switch(struct statement *stmt, sval_t sval)
 582 {
 583         struct statement *tmp;
 584
 585         __split_expr(stmt->switch_expression);
 586
 587         push_expression(&switch_expr_stack, stmt->switch_expression);
 588         __save_switch_states(top_expression(switch_expr_stack));
 589         nullify_path();
 590         __push_default();
 591         __push_breaks();
 592
 593         stmt = stmt->switch_statement;
 594
 595         if (!last_stmt)
 596                 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 597
 598         __push_scope_hooks();
 599         FOR_EACH_PTR(stmt->stmts, tmp) {
 600                 __smatch_lineno = tmp->pos.line;
 601                 if (is_case_val(tmp, sval)) {
 602                         __merge_switches(top_expression(switch_expr_stack),
 603                                          stmt->case_expression);
 604                         __pass_case_to_client(top_expression(switch_expr_stack),
 605                                               stmt->case_expression);
 606                 }
 607                 if (__path_is_null())
 608                         continue;
 609                 __split_stmt(tmp);
 610                 if (__path_is_null()) {
 611                         __set_default();
 612                         goto out;
 613                 }
 614         } END_FOR_EACH_PTR(tmp);
 615 out:
 616         __call_scope_hooks();
 617         if (!__pop_default())
 618                 __merge_switches(top_expression(switch_expr_stack),
 619                                  NULL);
 620         __discard_switches();
 621         __merge_breaks();
 622         pop_expression(&switch_expr_stack);
 623 }
 624
 625 void __split_stmt(struct statement *stmt)
 626 {
 627         sval_t sval;
 628
 629         if (!stmt)
 630                 goto out;
 631
 632         if (out_of_memory() || __bail_on_rest_of_function) {
 633                 static char *printed = NULL;
 634
 635                 if (printed != cur_func)
 636                         sm_msg("Function too hairy.  Giving up.");
 637                 final_pass = 0;  /* turn off sm_msg() from here */
 638                 printed = cur_func;
 639                 return;
 640         }
 641
 642         add_ptr_list(&big_statement_stack, stmt);
 643         free_expression_stack(&big_expression_stack);
 644         set_position(stmt->pos);
 645         print_unreached(stmt);
 646         __pass_to_client(stmt, STMT_HOOK);
 647
 648         switch (stmt->type) {
 649         case STMT_DECLARATION:
 650                 split_declaration(stmt->declaration);
 651                 break;
 652         case STMT_RETURN:
 653                 __split_expr(stmt->ret_value);
 654                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 655                 nullify_path();
 656                 break;
 657         case STMT_EXPRESSION:
 658                 __split_expr(stmt->expression);
 659                 break;
 660         case STMT_COMPOUND: {
 661                 struct statement *tmp;
 662
 663                 if (!last_stmt)
 664                         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 665                 __push_scope_hooks();
 666                 FOR_EACH_PTR(stmt->stmts, tmp) {
 667                         __split_stmt(tmp);
 668                 } END_FOR_EACH_PTR(tmp);
 669                 __call_scope_hooks();
 670                 break;
 671         }
 672         case STMT_IF:
 673                 if (known_condition_true(stmt->if_conditional)) {
 674                         __split_stmt(stmt->if_true);
 675                         break;
 676                 }
 677                 if (known_condition_false(stmt->if_conditional)) {
 678                         __split_stmt(stmt->if_false);
 679                         break;
 680                 }
 681                 if (option_known_conditions &&
 682                     implied_condition_true(stmt->if_conditional)) {
 683                         sm_info("this condition is true.");
 684                         __split_stmt(stmt->if_true);
 685                         break;
 686                 }
 687                 if (option_known_conditions &&
 688                     implied_condition_false(stmt->if_conditional)) {
 689                         sm_info("this condition is false.");
 690                         __split_stmt(stmt->if_false);
 691                         break;
 692                 }
 693                 __split_whole_condition(stmt->if_conditional);
 694                 __split_stmt(stmt->if_true);
 695                 if (empty_statement(stmt->if_true) &&
 696                         last_stmt_on_same_line() &&
 697                         !get_macro_name(stmt->if_true->pos))
 698                         sm_msg("warn: if();");
 699                 __push_true_states();
 700                 __use_false_states();
 701                 __split_stmt(stmt->if_false);
 702                 __merge_true_states();
 703                 break;
 704         case STMT_ITERATOR:
 705                 if (stmt->iterator_pre_condition)
 706                         handle_pre_loop(stmt);
 707                 else if (stmt->iterator_post_condition)
 708                         handle_post_loop(stmt);
 709                 else {
 710                         // these are for(;;) type loops.
 711                         handle_pre_loop(stmt);
 712                 }
 713                 break;
 714         case STMT_SWITCH:
 715                 if (get_value(stmt->switch_expression, &sval)) {
 716                         split_known_switch(stmt, sval);
 717                         break;
 718                 }
 719                 __split_expr(stmt->switch_expression);
 720                 push_expression(&switch_expr_stack, stmt->switch_expression);
 721                 __save_switch_states(top_expression(switch_expr_stack));
 722                 nullify_path();
 723                 __push_default();
 724                 __push_breaks();
 725                 __split_stmt(stmt->switch_statement);
 726                 if (!__pop_default())
 727                         __merge_switches(top_expression(switch_expr_stack),
 728                                       NULL);
 729                 __discard_switches();
 730                 __merge_breaks();
 731                 pop_expression(&switch_expr_stack);
 732                 break;
 733         case STMT_CASE:
 734                 __merge_switches(top_expression(switch_expr_stack),
 735                                       stmt->case_expression);
 736                 __pass_case_to_client(top_expression(switch_expr_stack),
 737                                       stmt->case_expression);
 738                 if (!stmt->case_expression)
 739                         __set_default();
 740                 __split_expr(stmt->case_expression);
 741                 __split_expr(stmt->case_to);
 742                 __split_stmt(stmt->case_statement);
 743                 break;
 744         case STMT_LABEL:
 745                 if (stmt->label_identifier &&
 746                     stmt->label_identifier->type == SYM_LABEL &&
 747                     stmt->label_identifier->ident) {
 748                         loop_count |= 0x80000000;
 749                         __merge_gotos(stmt->label_identifier->ident->name);
 750                 }
 751                 __split_stmt(stmt->label_statement);
 752                 break;
 753         case STMT_GOTO:
 754                 __split_expr(stmt->goto_expression);
 755                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 756                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 757                                 __process_breaks();
 758                         } else if (!strcmp(stmt->goto_label->ident->name,
 759                                            "continue")) {
 760                                 __process_continues();
 761                         }
 762                 } else if (stmt->goto_label &&
 763                            stmt->goto_label->type == SYM_LABEL &&
 764                            stmt->goto_label->ident) {
 765                         __save_gotos(stmt->goto_label->ident->name);
 766                 }
 767                 nullify_path();
 768                 break;
 769         case STMT_NONE:
 770                 break;
 771         case STMT_ASM:
 772                 __pass_to_client(stmt, ASM_HOOK);
 773                 __split_expr(stmt->asm_string);
 774                 split_asm_constraints(stmt->asm_outputs);
 775                 split_asm_constraints(stmt->asm_inputs);
 776                 split_asm_constraints(stmt->asm_clobbers);
 777                 break;
 778         case STMT_CONTEXT:
 779                 break;
 780         case STMT_RANGE:
 781                 __split_expr(stmt->range_expression);
 782                 __split_expr(stmt->range_low);
 783                 __split_expr(stmt->range_high);
 784                 break;
 785         }
 786         __pass_to_client(stmt, STMT_HOOK_AFTER);
 787 out:
 788         __process_post_op_stack();
 789 }
 790
 791 static void split_expr_list(struct expression_list *expr_list)
 792 {
 793         struct expression *expr;
 794
 795         FOR_EACH_PTR(expr_list, expr) {
 796                 __split_expr(expr);
 797                 __process_post_op_stack();
 798         } END_FOR_EACH_PTR(expr);
 799 }
 800
 801 static void split_sym(struct symbol *sym)
 802 {
 803         if (!sym)
 804                 return;
 805         if (!(sym->namespace & NS_SYMBOL))
 806                 return;
 807
 808         __split_stmt(sym->stmt);
 809         __split_expr(sym->array_size);
 810         split_symlist(sym->arguments);
 811         split_symlist(sym->symbol_list);
 812         __split_stmt(sym->inline_stmt);
 813         split_symlist(sym->inline_symbol_list);
 814 }
 815
 816 static void split_symlist(struct symbol_list *sym_list)
 817 {
 818         struct symbol *sym;
 819
 820         FOR_EACH_PTR(sym_list, sym) {
 821                 split_sym(sym);
 822         } END_FOR_EACH_PTR(sym);
 823 }
 824
 825 typedef void (fake_cb)(struct expression *expr);
 826
 827 static int member_to_number(struct expression *expr, struct ident *member)
 828 {
 829         struct symbol *type, *tmp;
 830         char *name;
 831         int i;
 832
 833         if (!member)
 834                 return -1;
 835         name = member->name;
 836
 837         type = get_type(expr);
 838         if (!type || type->type != SYM_STRUCT)
 839                 return -1;
 840
 841         i = -1;
 842         FOR_EACH_PTR(type->symbol_list, tmp) {
 843                 i++;
 844                 if (!tmp->ident)
 845                         continue;
 846                 if (strcmp(name, tmp->ident->name) == 0)
 847                         return i;
 848         } END_FOR_EACH_PTR(tmp);
 849         return -1;
 850 }
 851
 852 static struct ident *number_to_member(struct expression *expr, int num)
 853 {
 854         struct symbol *type, *member;
 855         int i = 0;
 856
 857         type = get_type(expr);
 858         if (!type || type->type != SYM_STRUCT)
 859                 return NULL;
 860
 861         FOR_EACH_PTR(type->symbol_list, member) {
 862                 if (i == num)
 863                         return member->ident;
 864                 i++;
 865         } END_FOR_EACH_PTR(member);
 866         return NULL;
 867 }
 868
 869 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 870
 871 struct member_set {
 872         struct ident *ident;
 873         int set;
 874 };
 875
 876 static struct member_set *alloc_member_set(struct symbol *type)
 877 {
 878         struct member_set *member_set;
 879         struct symbol *member;
 880         int member_count;
 881         int member_idx;
 882
 883         member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 884         member_set = malloc(member_count * sizeof(*member_set));
 885         member_idx = 0;
 886         FOR_EACH_PTR(type->symbol_list, member) {
 887                 member_set[member_idx].ident = member->ident;
 888                 member_set[member_idx].set = 0;
 889                 member_idx++;
 890         } END_FOR_EACH_PTR(member);
 891
 892         return member_set;
 893 }
 894
 895 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
 896 {
 897         int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 898         int i;
 899
 900         for (i = 0; i < member_count; i++) {
 901                 if (member_set[i].ident == ident) {
 902                         member_set[i].set = 1;
 903                         return;
 904                 }
 905         }
 906 //      crap.  this is buggy.
 907 //      sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
 908 }
 909
 910 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
 911 {
 912         struct expression *deref, *assign;
 913         struct symbol *member, *member_type;
 914         int member_idx;
 915
 916         member_idx = 0;
 917         FOR_EACH_PTR(type->symbol_list, member) {
 918                 if (!member->ident || member_set[member_idx].set) {
 919                         member_idx++;
 920                         continue;
 921                 }
 922                 member_type = get_real_base_type(member);
 923                 if (!member_type || member_type->type == SYM_ARRAY) {
 924                         member_idx++;
 925                         continue;
 926                 }
 927                 /* TODO: this should be handled recursively and not ignored */
 928                 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION) {
 929                         member_idx++;
 930                         continue;
 931                 }
 932                 deref = member_expression(symbol, '.', member->ident);
 933                 assign = assign_expression(deref, zero_expr());
 934                 __split_expr(assign);
 935                 member_idx++;
 936         } END_FOR_EACH_PTR(member);
 937
 938 }
 939
 940 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 941 {
 942         struct expression *deref, *assign, *tmp;
 943         struct symbol *struct_type, *type;
 944         struct ident *member;
 945         int member_idx;
 946         struct member_set *member_set;
 947
 948         struct_type = get_type(symbol);
 949         if (!struct_type ||
 950             (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
 951                 return;
 952
 953         member_set = alloc_member_set(struct_type);
 954
 955         member_idx = 0;
 956         FOR_EACH_PTR(members, tmp) {
 957                 member = number_to_member(symbol, member_idx);
 958                 while (tmp->type == EXPR_IDENTIFIER) {
 959                         member = tmp->expr_ident;
 960                         member_idx = member_to_number(symbol, member);
 961                         tmp = tmp->ident_expression;
 962                 }
 963                 mark_member_as_set(struct_type, member_set, member);
 964                 member_idx++;
 965                 deref = member_expression(symbol, '.', member);
 966                 if (tmp->type == EXPR_INITIALIZER) {
 967                         type = get_type(deref);
 968                         if (type && type->type == SYM_ARRAY)
 969                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 970                         else
 971                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 972                 } else {
 973                         assign = assign_expression(deref, tmp);
 974                         fake_cb(assign);
 975                 }
 976         } END_FOR_EACH_PTR(tmp);
 977
 978         set_unset_to_zero(symbol, struct_type, member_set);
 979 }
 980
 981 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
 982 {
 983         fake_member_assigns_helper(symbol_expression(sym),
 984                                    sym->initializer->expr_list, fake_cb);
 985 }
 986
 987 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
 988 {
 989         struct expression *offset, *binop, *assign, *tmp;
 990         struct symbol *type;
 991         int idx;
 992
 993         idx = 0;
 994         FOR_EACH_PTR(expr_list, tmp) {
 995                 if (tmp->type == EXPR_INDEX) {
 996                         if (tmp->idx_from != tmp->idx_to)
 997                                 return;
 998                         idx = tmp->idx_from;
 999                         if (!tmp->idx_expression)
1000                                 goto next;
1001                         tmp = tmp->idx_expression;
1002                 }
1003                 offset = value_expr(idx);
1004                 binop = array_element_expression(array, offset);
1005                 if (tmp->type == EXPR_INITIALIZER) {
1006                         type = get_type(binop);
1007                         if (type && type->type == SYM_ARRAY)
1008                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
1009                         else
1010                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
1011                 } else {
1012                         assign = assign_expression(binop, tmp);
1013                         fake_cb(assign);
1014                 }
1015 next:
1016                 idx++;
1017         } END_FOR_EACH_PTR(tmp);
1018 }
1019
1020 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1021 {
1022         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1023 }
1024
1025 static void fake_assign_expr(struct symbol *sym)
1026 {
1027         struct expression *assign, *symbol;
1028
1029         symbol = symbol_expression(sym);
1030         assign = assign_expression(symbol, sym->initializer);
1031         __split_expr(assign);
1032 }
1033
1034 static void call_split_expr(struct expression *expr)
1035 {
1036         __split_expr(expr);
1037 }
1038
1039 static void do_initializer_stuff(struct symbol *sym)
1040 {
1041         if (!sym->initializer)
1042                 return;
1043
1044         if (sym->initializer->type == EXPR_INITIALIZER) {
1045                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1046                         fake_element_assigns(sym, call_split_expr);
1047                 else
1048                         fake_member_assigns(sym, call_split_expr);
1049         } else {
1050                 fake_assign_expr(sym);
1051         }
1052 }
1053
1054 static void split_declaration(struct symbol_list *sym_list)
1055 {
1056         struct symbol *sym;
1057
1058         FOR_EACH_PTR(sym_list, sym) {
1059                 __pass_to_client(sym, DECLARATION_HOOK);
1060                 do_initializer_stuff(sym);
1061                 split_sym(sym);
1062         } END_FOR_EACH_PTR(sym);
1063 }
1064
1065 static void call_global_assign_hooks(struct expression *assign)
1066 {
1067         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1068 }
1069
1070 static void fake_global_assign(struct symbol *sym)
1071 {
1072         struct expression *assign, *symbol;
1073
1074         if (get_real_base_type(sym)->type == SYM_ARRAY) {
1075                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1076                         fake_element_assigns(sym, call_global_assign_hooks);
1077                 } else if (sym->initializer) {
1078                         symbol = symbol_expression(sym);
1079                         assign = assign_expression(symbol, sym->initializer);
1080                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1081                 } else {
1082                         fake_element_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1083                 }
1084         } else if (get_real_base_type(sym)->type == SYM_STRUCT) {
1085                 if (sym->initializer && sym->initializer->type == EXPR_INITIALIZER) {
1086                         fake_member_assigns(sym, call_global_assign_hooks);
1087                 } else if (sym->initializer) {
1088                         symbol = symbol_expression(sym);
1089                         assign = assign_expression(symbol, sym->initializer);
1090                         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1091                 } else {
1092                         fake_member_assigns_helper(symbol_expression(sym), NULL, call_global_assign_hooks);
1093                 }
1094         } else {
1095                 symbol = symbol_expression(sym);
1096                 if (sym->initializer)
1097                         assign = assign_expression(symbol, sym->initializer);
1098                 else
1099                         assign = assign_expression(symbol, zero_expr());
1100                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1101         }
1102 }
1103
1104 static void start_function_definition(struct symbol *sym)
1105 {
1106         __in_function_def = 1;
1107         __pass_to_client(sym, FUNC_DEF_HOOK);
1108         __in_function_def = 0;
1109         __pass_to_client(sym, AFTER_DEF_HOOK);
1110
1111 }
1112
1113 static void split_function(struct symbol *sym)
1114 {
1115         struct symbol *base_type = get_base_type(sym);
1116
1117         cur_func_sym = sym;
1118         if (sym->ident)
1119                 cur_func = sym->ident->name;
1120         __smatch_lineno = sym->pos.line;
1121         last_stmt = NULL;
1122         loop_count = 0;
1123         sm_debug("new function:  %s\n", cur_func);
1124         __slist_id = 0;
1125         if (option_two_passes) {
1126                 __unnullify_path();
1127                 loop_num = 0;
1128                 final_pass = 0;
1129                 start_function_definition(sym);
1130                 __split_stmt(base_type->stmt);
1131                 __split_stmt(base_type->inline_stmt);
1132                 nullify_path();
1133         }
1134         __unnullify_path();
1135         loop_num = 0;
1136         start_function_definition(sym);
1137         __split_stmt(base_type->stmt);
1138         __split_stmt(base_type->inline_stmt);
1139         __pass_to_client(sym, END_FUNC_HOOK);
1140         __pass_to_client(sym, AFTER_FUNC_HOOK);
1141         cur_func_sym = NULL;
1142         cur_func = NULL;
1143         clear_all_states();
1144         free_data_info_allocs();
1145         free_expression_stack(&switch_expr_stack);
1146         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1147         __bail_on_rest_of_function = 0;
1148 }
1149
1150 static void parse_inline(struct expression *call)
1151 {
1152         struct symbol *base_type;
1153         int loop_num_bak = loop_num;
1154         int final_pass_bak = final_pass;
1155         char *cur_func_bak = cur_func;
1156         struct statement_list *big_statement_stack_bak = big_statement_stack;
1157         struct expression_list *big_expression_stack_bak = big_expression_stack;
1158         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1159         struct symbol *cur_func_sym_bak = cur_func_sym;
1160
1161         __pass_to_client(call, INLINE_FN_START);
1162         final_pass = 0;  /* don't print anything */
1163         __inline_fn = call;
1164
1165         base_type = get_base_type(call->fn->symbol);
1166         cur_func_sym = call->fn->symbol;
1167         if (call->fn->symbol->ident)
1168                 cur_func = call->fn->symbol->ident->name;
1169         else
1170                 cur_func = NULL;
1171         set_position(call->fn->symbol->pos);
1172
1173         save_all_states();
1174         nullify_all_states();
1175         big_statement_stack = NULL;
1176         big_expression_stack = NULL;
1177         switch_expr_stack = NULL;
1178
1179         sm_debug("inline function:  %s\n", cur_func);
1180         __unnullify_path();
1181         loop_num = 0;
1182         start_function_definition(call->fn->symbol);
1183         __split_stmt(base_type->stmt);
1184         __split_stmt(base_type->inline_stmt);
1185         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1186         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1187
1188         free_expression_stack(&switch_expr_stack);
1189         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1190         nullify_path();
1191
1192         loop_num = loop_num_bak;
1193         final_pass = final_pass_bak;
1194         cur_func_sym = cur_func_sym_bak;
1195         cur_func = cur_func_bak;
1196         big_statement_stack = big_statement_stack_bak;
1197         big_expression_stack = big_expression_stack_bak;
1198         switch_expr_stack = switch_expr_stack_bak;
1199
1200         restore_all_states();
1201         set_position(call->pos);
1202         __inline_fn = NULL;
1203         __pass_to_client(call, INLINE_FN_END);
1204 }
1205
1206 static struct symbol_list *inlines_called;
1207 static void add_inline_function(struct symbol *sym)
1208 {
1209         static struct symbol_list *already_added;
1210         struct symbol *tmp;
1211
1212         FOR_EACH_PTR(already_added, tmp) {
1213                 if (tmp == sym)
1214                         return;
1215         } END_FOR_EACH_PTR(tmp);
1216
1217         add_ptr_list(&already_added, sym);
1218         add_ptr_list(&inlines_called, sym);
1219 }
1220
1221 static void process_inlines()
1222 {
1223         struct symbol *tmp;
1224
1225         FOR_EACH_PTR(inlines_called, tmp) {
1226                 split_function(tmp);
1227         } END_FOR_EACH_PTR(tmp);
1228         free_ptr_list(&inlines_called);
1229 }
1230
1231 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1232 {
1233         struct symbol *sym;
1234
1235         FOR_EACH_PTR_REVERSE(big_list, sym) {
1236                 if (!sym->scope)
1237                         continue;
1238                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1239                         return sym;
1240                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1241                         return sym;
1242         } END_FOR_EACH_PTR_REVERSE(sym);
1243
1244         return NULL;
1245 }
1246
1247 static void split_inlines_in_scope(struct symbol *sym)
1248 {
1249         struct symbol *base;
1250         struct symbol_list *scope_list;
1251         int stream;
1252
1253         scope_list = sym->scope->symbols;
1254         stream = sym->pos.stream;
1255
1256         /* find the last static symbol in the file */
1257         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1258                 if (sym->pos.stream != stream)
1259                         continue;
1260                 if (sym->type != SYM_NODE)
1261                         continue;
1262                 base = get_base_type(sym);
1263                 if (!base)
1264                         continue;
1265                 if (base->type != SYM_FN)
1266                         continue;
1267                 if (!base->inline_stmt)
1268                         continue;
1269                 add_inline_function(sym);
1270         } END_FOR_EACH_PTR_REVERSE(sym);
1271
1272         process_inlines();
1273 }
1274
1275 static void split_inlines(struct symbol_list *sym_list)
1276 {
1277         struct symbol *sym;
1278
1279         sym = get_last_scoped_symbol(sym_list, 0);
1280         if (sym)
1281                 split_inlines_in_scope(sym);
1282         sym = get_last_scoped_symbol(sym_list, 1);
1283         if (sym)
1284                 split_inlines_in_scope(sym);
1285 }
1286
1287 static void split_functions(struct symbol_list *sym_list)
1288 {
1289         struct symbol *sym;
1290
1291         FOR_EACH_PTR(sym_list, sym) {
1292                 set_position(sym->pos);
1293                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1294                         split_function(sym);
1295                         process_inlines();
1296                 } else {
1297                         __pass_to_client(sym, BASE_HOOK);
1298                         fake_global_assign(sym);
1299                 }
1300         } END_FOR_EACH_PTR(sym);
1301         split_inlines(sym_list);
1302         __pass_to_client(sym_list, END_FILE_HOOK);
1303 }
1304
1305 void smatch(int argc, char **argv)
1306 {
1307
1308         struct string_list *filelist = NULL;
1309         struct symbol_list *sym_list;
1310
1311         if (argc < 2) {
1312                 printf("Usage:  smatch [--debug] <filename.c>\n");
1313                 exit(1);
1314         }
1315         sparse_initialize(argc, argv, &filelist);
1316         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1317                 if (option_file_output) {
1318                         char buf[256];
1319
1320                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1321                         sm_outfd = fopen(buf, "w");
1322                         if (!sm_outfd) {
1323                                 printf("Error:  Cannot open %s\n", base_file);
1324                                 exit(1);
1325                         }
1326                 }
1327                 sym_list = sparse_keep_tokens(base_file);
1328                 split_functions(sym_list);
1329         } END_FOR_EACH_PTR_NOTAG(base_file);
1330 }