smatch_flow.c

   1 /*
   2  * sparse/smatch_flow.c
   3  *
   4  * Copyright (C) 2006,2008 Dan Carpenter.
   5  *
   6  *  Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #define _GNU_SOURCE 1
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include "token.h"
  14 #include "scope.h"
  15 #include "smatch.h"
  16 #include "smatch_expression_stacks.h"
  17 #include "smatch_extra.h"
  18 #include "smatch_slist.h"
  19
  20 int final_pass;
  21 int __inline_call;
  22 struct expression  *__inline_fn;
  23
  24 static int __smatch_lineno = 0;
  25
  26 static char *base_file;
  27 static const char *filename;
  28 static char *pathname;
  29 static char *full_filename;
  30 static char *cur_func;
  31 static int loop_count;
  32 int __expr_stmt_count;
  33 int __in_function_def;
  34 static struct expression_list *switch_expr_stack = NULL;
  35 static struct expression_list *post_op_stack = NULL;
  36
  37 struct expression_list *big_expression_stack;
  38 struct statement_list *big_statement_stack;
  39 int __in_pre_condition = 0;
  40 int __bail_on_rest_of_function = 0;
  41 char *get_function(void) { return cur_func; }
  42 int get_lineno(void) { return __smatch_lineno; }
  43 int inside_loop(void) { return !!loop_count; }
  44 struct expression *get_switch_expr(void) { return top_expression(switch_expr_stack); }
  45 int in_expression_statement(void) { return !!__expr_stmt_count; }
  46
  47 static void split_symlist(struct symbol_list *sym_list);
  48 static void split_declaration(struct symbol_list *sym_list);
  49 static void split_expr_list(struct expression_list *expr_list);
  50 static void add_inline_function(struct symbol *sym);
  51 static void parse_inline(struct expression *expr);
  52
  53 int option_assume_loops = 0;
  54 int option_known_conditions = 0;
  55 int option_two_passes = 0;
  56 struct symbol *cur_func_sym = NULL;
  57
  58 int outside_of_function(void)
  59 {
  60         return cur_func_sym == NULL;
  61 }
  62
  63 const char *get_filename(void)
  64 {
  65         if (option_info)
  66                 return base_file;
  67         if (option_full_path)
  68                 return full_filename;
  69         return filename;
  70 }
  71
  72 const char *get_base_file(void)
  73 {
  74         return base_file;
  75 }
  76
  77 static void set_position(struct position pos)
  78 {
  79         int len;
  80         static int prev_stream = -1;
  81
  82         if (pos.stream == 0 && pos.line == 0)
  83                 return;
  84
  85         __smatch_lineno = pos.line;
  86
  87         if (pos.stream == prev_stream)
  88                 return;
  89
  90         filename = stream_name(pos.stream);
  91
  92         free(full_filename);
  93         pathname = getcwd(NULL, 0);
  94         if (pathname) {
  95                 len = strlen(pathname) + 1 + strlen(filename) + 1;
  96                 full_filename = malloc(len);
  97                 snprintf(full_filename, len, "%s/%s", pathname, filename);
  98         } else {
  99                 full_filename = alloc_string(filename);
 100         }
 101         free(pathname);
 102 }
 103
 104 static int is_inline_func(struct expression *expr)
 105 {
 106         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 107                 return 0;
 108         if (expr->symbol->ctype.modifiers & MOD_INLINE)
 109                 return 1;
 110         return 0;
 111 }
 112
 113 static int is_noreturn_func(struct expression *expr)
 114 {
 115         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 116                 return 0;
 117         if (expr->symbol->ctype.modifiers & MOD_NORETURN)
 118                 return 1;
 119         return 0;
 120 }
 121
 122 int inlinable(struct expression *expr)
 123 {
 124         struct symbol *sym;
 125
 126         if (__inline_fn)  /* don't nest */
 127                 return 0;
 128
 129         if (expr->type != EXPR_SYMBOL || !expr->symbol)
 130                 return 0;
 131         sym = get_base_type(expr->symbol);
 132         if (sym->stmt && sym->stmt->type == STMT_COMPOUND) {
 133                 if (ptr_list_size((struct ptr_list *)sym->stmt->stmts) <= 10)
 134                         return 1;
 135                 return 0;
 136         }
 137         if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND) {
 138                 if (ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts) <= 10)
 139                         return 1;
 140                 return 0;
 141         }
 142         return 0;
 143 }
 144
 145 void __process_post_op_stack(void)
 146 {
 147         struct expression *expr;
 148
 149         FOR_EACH_PTR(post_op_stack, expr) {
 150                 __pass_to_client(expr, OP_HOOK);
 151         } END_FOR_EACH_PTR(expr);
 152
 153         __free_ptr_list((struct ptr_list **)&post_op_stack);
 154 }
 155
 156 void __split_expr(struct expression *expr)
 157 {
 158         if (!expr)
 159                 return;
 160
 161         // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
 162
 163         push_expression(&big_expression_stack, expr);
 164         set_position(expr->pos);
 165         __pass_to_client(expr, EXPR_HOOK);
 166
 167         switch (expr->type) {
 168         case EXPR_PREOP:
 169                 if (expr->op == '*')
 170                         __pass_to_client(expr, DEREF_HOOK);
 171                 __split_expr(expr->unop);
 172                 __pass_to_client(expr, OP_HOOK);
 173                 break;
 174         case EXPR_POSTOP:
 175                 __split_expr(expr->unop);
 176                 push_expression(&post_op_stack, expr);
 177                 break;
 178         case EXPR_STATEMENT:
 179                 __expr_stmt_count++;
 180                 __split_stmt(expr->statement);
 181                 __expr_stmt_count--;
 182                 break;
 183         case EXPR_LOGICAL:
 184         case EXPR_COMPARE:
 185                 __pass_to_client(expr, LOGIC_HOOK);
 186                 __handle_logic(expr);
 187                 break;
 188         case EXPR_BINOP:
 189                 __pass_to_client(expr, BINOP_HOOK);
 190         case EXPR_COMMA:
 191                 __split_expr(expr->left);
 192                 __process_post_op_stack();
 193                 __split_expr(expr->right);
 194                 break;
 195         case EXPR_ASSIGNMENT: {
 196                 struct expression *tmp;
 197
 198                 if (!expr->right)
 199                         break;
 200
 201                 __pass_to_client(expr, RAW_ASSIGNMENT_HOOK);
 202
 203                 /* foo = !bar() */
 204                 if (__handle_condition_assigns(expr))
 205                         break;
 206                 /* foo = (x < 5 ? foo : 5); */
 207                 if (__handle_select_assigns(expr))
 208                         break;
 209                 /* foo = ({frob(); frob(); frob(); 1;}) */
 210                 if (__handle_expr_statement_assigns(expr))
 211                         break;
 212
 213                 __split_expr(expr->right);
 214                 if (outside_of_function())
 215                         __pass_to_client(expr, GLOBAL_ASSIGNMENT_HOOK);
 216                 else
 217                         __pass_to_client(expr, ASSIGNMENT_HOOK);
 218                 tmp = strip_expr(expr->right);
 219                 if (tmp->type == EXPR_CALL)
 220                         __pass_to_client(expr, CALL_ASSIGNMENT_HOOK);
 221                 if (get_macro_name(tmp->pos) &&
 222                     get_macro_name(expr->pos) != get_macro_name(tmp->pos))
 223                         __pass_to_client(expr, MACRO_ASSIGNMENT_HOOK);
 224                 __split_expr(expr->left);
 225                 break;
 226         }
 227         case EXPR_DEREF:
 228                 __pass_to_client(expr, DEREF_HOOK);
 229                 __split_expr(expr->deref);
 230                 break;
 231         case EXPR_SLICE:
 232                 __split_expr(expr->base);
 233                 break;
 234         case EXPR_CAST:
 235         case EXPR_FORCE_CAST:
 236                 __pass_to_client(expr, CAST_HOOK);
 237                 __split_expr(expr->cast_expression);
 238                 break;
 239         case EXPR_SIZEOF:
 240                 if (expr->cast_expression)
 241                         __pass_to_client(strip_parens(expr->cast_expression),
 242                                          SIZEOF_HOOK);
 243                 break;
 244         case EXPR_OFFSETOF:
 245         case EXPR_ALIGNOF:
 246                 evaluate_expression(expr);
 247                 break;
 248         case EXPR_CONDITIONAL:
 249         case EXPR_SELECT:
 250                 if (known_condition_true(expr->conditional)) {
 251                         __split_expr(expr->cond_true);
 252                         break;
 253                 }
 254                 if (known_condition_false(expr->conditional)) {
 255                         __split_expr(expr->cond_false);
 256                         break;
 257                 }
 258                 __pass_to_client(expr, SELECT_HOOK);
 259                 __split_whole_condition(expr->conditional);
 260                 __split_expr(expr->cond_true);
 261                 __push_true_states();
 262                 __use_false_states();
 263                 __split_expr(expr->cond_false);
 264                 __merge_true_states();
 265                 break;
 266         case EXPR_CALL:
 267                 if (sym_name_is("__builtin_constant_p", expr->fn))
 268                         break;
 269                 split_expr_list(expr->args);
 270                 __split_expr(expr->fn);
 271                 if (is_inline_func(expr->fn))
 272                         add_inline_function(expr->fn->symbol);
 273                 if (inlinable(expr->fn))
 274                         __inline_call = 1;
 275                 __process_post_op_stack();
 276                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 277                 __inline_call = 0;
 278                 if (inlinable(expr->fn)) {
 279                         parse_inline(expr);
 280                 }
 281                 __pass_to_client(expr, CALL_HOOK_AFTER_INLINE);
 282                 if (is_noreturn_func(expr->fn))
 283                         nullify_path();
 284                 break;
 285         case EXPR_INITIALIZER:
 286                 split_expr_list(expr->expr_list);
 287                 break;
 288         case EXPR_IDENTIFIER:
 289                 __split_expr(expr->ident_expression);
 290                 break;
 291         case EXPR_INDEX:
 292                 __split_expr(expr->idx_expression);
 293                 break;
 294         case EXPR_POS:
 295                 __split_expr(expr->init_expr);
 296                 break;
 297         case EXPR_SYMBOL:
 298                 __pass_to_client(expr, SYM_HOOK);
 299                 break;
 300         case EXPR_STRING:
 301                 __pass_to_client(expr, STRING_HOOK);
 302                 break;
 303         default:
 304                 break;
 305         };
 306         pop_expression(&big_expression_stack);
 307 }
 308
 309 static int is_forever_loop(struct statement *stmt)
 310 {
 311         struct expression *expr;
 312
 313         expr = strip_expr(stmt->iterator_pre_condition);
 314         if (!expr)
 315                 expr = stmt->iterator_post_condition;
 316         if (!expr) {
 317                 /* this is a for(;;) loop... */
 318                 return 1;
 319         }
 320
 321         if (expr->type == EXPR_VALUE && expr->value == 1)
 322                 return 1;
 323
 324         return 0;
 325 }
 326
 327 static int loop_num;
 328 static char *get_loop_name(int num)
 329 {
 330         char buf[256];
 331
 332         snprintf(buf, 255, "-loop%d", num);
 333         buf[255] = '\0';
 334         return alloc_sname(buf);
 335 }
 336
 337 /*
 338  * Pre Loops are while and for loops.
 339  */
 340 static void handle_pre_loop(struct statement *stmt)
 341 {
 342         int once_through; /* we go through the loop at least once */
 343         struct sm_state *extra_sm = NULL;
 344         int unchanged = 0;
 345         char *loop_name;
 346         struct state_list *slist = NULL;
 347         struct sm_state *sm = NULL;
 348
 349         loop_name = get_loop_name(loop_num);
 350         loop_num++;
 351
 352         __split_stmt(stmt->iterator_pre_statement);
 353
 354         once_through = implied_condition_true(stmt->iterator_pre_condition);
 355
 356         loop_count++;
 357         __push_continues();
 358         __push_breaks();
 359
 360         __merge_gotos(loop_name);
 361
 362         extra_sm = __extra_handle_canonical_loops(stmt, &slist);
 363         __in_pre_condition++;
 364         __pass_to_client(stmt, PRELOOP_HOOK);
 365         __split_whole_condition(stmt->iterator_pre_condition);
 366         __in_pre_condition--;
 367         FOR_EACH_PTR(slist, sm) {
 368                 set_state(sm->owner, sm->name, sm->sym, sm->state);
 369         } END_FOR_EACH_PTR(sm);
 370         free_slist(&slist);
 371         if (extra_sm)
 372                 extra_sm = get_sm_state(extra_sm->owner, extra_sm->name, extra_sm->sym);
 373
 374         if (option_assume_loops)
 375                 once_through = 1;
 376
 377         __split_stmt(stmt->iterator_statement);
 378         __warn_on_silly_pre_loops();
 379         if (is_forever_loop(stmt)) {
 380                 struct state_list *slist;
 381
 382                 __save_gotos(loop_name);
 383
 384                 __push_fake_cur_slist();
 385                 __split_stmt(stmt->iterator_post_statement);
 386                 slist = __pop_fake_cur_slist();
 387
 388                 __discard_continues();
 389                 __discard_false_states();
 390                 __use_breaks();
 391
 392                 if (!__path_is_null())
 393                         __merge_slist_into_cur(slist);
 394                 free_slist(&slist);
 395         } else {
 396                 __merge_continues();
 397                 unchanged = __iterator_unchanged(extra_sm);
 398                 __split_stmt(stmt->iterator_post_statement);
 399                 __save_gotos(loop_name);
 400                 __split_whole_condition(stmt->iterator_pre_condition);
 401                 nullify_path();
 402                 __merge_false_states();
 403                 if (once_through)
 404                         __discard_false_states();
 405                 else
 406                         __merge_false_states();
 407
 408                 if (extra_sm && unchanged)
 409                         __extra_pre_loop_hook_after(extra_sm,
 410                                                 stmt->iterator_post_statement,
 411                                                 stmt->iterator_pre_condition);
 412                 __merge_breaks();
 413         }
 414         loop_count--;
 415 }
 416
 417 /*
 418  * Post loops are do {} while();
 419  */
 420 static void handle_post_loop(struct statement *stmt)
 421 {
 422         char *loop_name;
 423
 424         loop_name = get_loop_name(loop_num);
 425         loop_num++;
 426         loop_count++;
 427
 428         __push_continues();
 429         __push_breaks();
 430         __merge_gotos(loop_name);
 431         __split_stmt(stmt->iterator_statement);
 432         __merge_continues();
 433         if (!is_zero(stmt->iterator_post_condition))
 434                 __save_gotos(loop_name);
 435
 436         if (is_forever_loop(stmt)) {
 437                 __use_breaks();
 438         } else {
 439                 __split_whole_condition(stmt->iterator_post_condition);
 440                 __use_false_states();
 441                 __merge_breaks();
 442         }
 443         loop_count--;
 444 }
 445
 446 static int empty_statement(struct statement *stmt)
 447 {
 448         if (!stmt)
 449                 return 0;
 450         if (stmt->type == STMT_EXPRESSION && !stmt->expression)
 451                 return 1;
 452         return 0;
 453 }
 454
 455 static int last_stmt_on_same_line()
 456 {
 457         struct statement *stmt;
 458         int i = 0;
 459
 460         FOR_EACH_PTR_REVERSE(big_statement_stack, stmt) {
 461                 if (!i++)
 462                         continue;
 463                 if  (stmt->pos.line == get_lineno())
 464                         return 1;
 465                 return 0;
 466         } END_FOR_EACH_PTR_REVERSE(stmt);
 467         return 0;
 468 }
 469
 470 static struct statement *last_stmt;
 471 static int is_last_stmt(struct statement *stmt)
 472 {
 473         if (stmt == last_stmt)
 474                 return 1;
 475         return 0;
 476 }
 477
 478 static void print_unreached_initializers(struct symbol_list *sym_list)
 479 {
 480         struct symbol *sym;
 481
 482         FOR_EACH_PTR(sym_list, sym) {
 483                 if (sym->initializer)
 484                         sm_msg("info: '%s' is not actually initialized (unreached code).",
 485                                 (sym->ident ? sym->ident->name : "this variable"));
 486         } END_FOR_EACH_PTR(sym);
 487 }
 488
 489 static void print_unreached(struct statement *stmt)
 490 {
 491         static int print = 1;
 492
 493         if (__inline_fn)
 494                 return;
 495
 496         if (!__path_is_null()) {
 497                 print = 1;
 498                 return;
 499         }
 500         if (!print)
 501                 return;
 502
 503         switch (stmt->type) {
 504         case STMT_COMPOUND: /* after a switch before a case stmt */
 505         case STMT_RANGE:
 506         case STMT_CASE:
 507         case STMT_LABEL:
 508                 return;
 509         case STMT_DECLARATION: /* switch (x) { int a; case foo: ... */
 510                 print_unreached_initializers(stmt->declaration);
 511                 return;
 512         case STMT_RETURN: /* gcc complains if you don't have a return statement */
 513                 if (is_last_stmt(stmt))
 514                         return;
 515                 break;
 516         case STMT_GOTO:
 517                 if (!option_spammy)
 518                         return;
 519                 break;
 520         default:
 521                 break;
 522         }
 523         if (!option_spammy && empty_statement(stmt))
 524                 return;
 525         sm_msg("info: ignoring unreachable code.");
 526         print = 0;
 527 }
 528
 529 static void split_asm_constraints(struct expression_list *expr_list)
 530 {
 531         struct expression *expr;
 532         int state = 0;
 533
 534         FOR_EACH_PTR(expr_list, expr) {
 535                 switch (state) {
 536                 case 0: /* identifier */
 537                 case 1: /* constraint */
 538                         state++;
 539                         continue;
 540                 case 2: /* expression */
 541                         state = 0;
 542                         __split_expr(expr);
 543                         continue;
 544                 }
 545         } END_FOR_EACH_PTR(expr);
 546 }
 547
 548 static int is_case_val(struct statement *stmt, sval_t sval)
 549 {
 550         sval_t case_sval;
 551
 552         if (stmt->type != STMT_CASE)
 553                 return 0;
 554         if (!stmt->case_expression) {
 555                 __set_default();
 556                 return 1;
 557         }
 558         if (!get_value(stmt->case_expression, &case_sval))
 559                 return 0;
 560         if (case_sval.value == sval.value)
 561                 return 1;
 562         return 0;
 563 }
 564
 565 static void split_known_switch(struct statement *stmt, sval_t sval)
 566 {
 567         struct statement *tmp;
 568
 569         __split_expr(stmt->switch_expression);
 570
 571         push_expression(&switch_expr_stack, stmt->switch_expression);
 572         __save_switch_states(top_expression(switch_expr_stack));
 573         nullify_path();
 574         __push_default();
 575         __push_breaks();
 576
 577         stmt = stmt->switch_statement;
 578
 579         if (!last_stmt)
 580                 last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 581
 582         __push_scope_hooks();
 583         FOR_EACH_PTR(stmt->stmts, tmp) {
 584                 __smatch_lineno = tmp->pos.line;
 585                 if (is_case_val(tmp, sval)) {
 586                         __merge_switches(top_expression(switch_expr_stack),
 587                                          stmt->case_expression);
 588                         __pass_case_to_client(top_expression(switch_expr_stack),
 589                                               stmt->case_expression);
 590                 }
 591                 if (__path_is_null())
 592                         continue;
 593                 __split_stmt(tmp);
 594                 if (__path_is_null()) {
 595                         __set_default();
 596                         goto out;
 597                 }
 598         } END_FOR_EACH_PTR(tmp);
 599 out:
 600         __call_scope_hooks();
 601         if (!__pop_default())
 602                 __merge_switches(top_expression(switch_expr_stack),
 603                                  NULL);
 604         __discard_switches();
 605         __merge_breaks();
 606         pop_expression(&switch_expr_stack);
 607 }
 608
 609 void __split_stmt(struct statement *stmt)
 610 {
 611         sval_t sval;
 612
 613         if (!stmt)
 614                 goto out;
 615
 616         if (out_of_memory() || __bail_on_rest_of_function) {
 617                 static char *printed = NULL;
 618
 619                 if (printed != cur_func)
 620                         sm_msg("Function too hairy.  Giving up.");
 621                 final_pass = 0;  /* turn off sm_msg() from here */
 622                 printed = cur_func;
 623                 return;
 624         }
 625
 626         add_ptr_list(&big_statement_stack, stmt);
 627         free_expression_stack(&big_expression_stack);
 628         set_position(stmt->pos);
 629         print_unreached(stmt);
 630         __pass_to_client(stmt, STMT_HOOK);
 631
 632         switch (stmt->type) {
 633         case STMT_DECLARATION:
 634                 split_declaration(stmt->declaration);
 635                 break;
 636         case STMT_RETURN:
 637                 __split_expr(stmt->ret_value);
 638                 __pass_to_client(stmt->ret_value, RETURN_HOOK);
 639                 nullify_path();
 640                 break;
 641         case STMT_EXPRESSION:
 642                 __split_expr(stmt->expression);
 643                 break;
 644         case STMT_COMPOUND: {
 645                 struct statement *tmp;
 646
 647                 if (!last_stmt)
 648                         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 649                 __push_scope_hooks();
 650                 FOR_EACH_PTR(stmt->stmts, tmp) {
 651                         __split_stmt(tmp);
 652                 } END_FOR_EACH_PTR(tmp);
 653                 __call_scope_hooks();
 654                 break;
 655         }
 656         case STMT_IF:
 657                 if (known_condition_true(stmt->if_conditional)) {
 658                         __split_stmt(stmt->if_true);
 659                         break;
 660                 }
 661                 if (known_condition_false(stmt->if_conditional)) {
 662                         __split_stmt(stmt->if_false);
 663                         break;
 664                 }
 665                 if (option_known_conditions &&
 666                     implied_condition_true(stmt->if_conditional)) {
 667                         sm_info("this condition is true.");
 668                         __split_stmt(stmt->if_true);
 669                         break;
 670                 }
 671                 if (option_known_conditions &&
 672                     implied_condition_false(stmt->if_conditional)) {
 673                         sm_info("this condition is false.");
 674                         __split_stmt(stmt->if_false);
 675                         break;
 676                 }
 677                 __split_whole_condition(stmt->if_conditional);
 678                 __split_stmt(stmt->if_true);
 679                 if (empty_statement(stmt->if_true) &&
 680                         last_stmt_on_same_line() &&
 681                         !get_macro_name(stmt->if_true->pos))
 682                         sm_msg("warn: if();");
 683                 __push_true_states();
 684                 __use_false_states();
 685                 __split_stmt(stmt->if_false);
 686                 __merge_true_states();
 687                 break;
 688         case STMT_ITERATOR:
 689                 if (stmt->iterator_pre_condition)
 690                         handle_pre_loop(stmt);
 691                 else if (stmt->iterator_post_condition)
 692                         handle_post_loop(stmt);
 693                 else {
 694                         // these are for(;;) type loops.
 695                         handle_pre_loop(stmt);
 696                 }
 697                 break;
 698         case STMT_SWITCH:
 699                 if (get_value(stmt->switch_expression, &sval)) {
 700                         split_known_switch(stmt, sval);
 701                         break;
 702                 }
 703                 __split_expr(stmt->switch_expression);
 704                 push_expression(&switch_expr_stack, stmt->switch_expression);
 705                 __save_switch_states(top_expression(switch_expr_stack));
 706                 nullify_path();
 707                 __push_default();
 708                 __push_breaks();
 709                 __split_stmt(stmt->switch_statement);
 710                 if (!__pop_default())
 711                         __merge_switches(top_expression(switch_expr_stack),
 712                                       NULL);
 713                 __discard_switches();
 714                 __merge_breaks();
 715                 pop_expression(&switch_expr_stack);
 716                 break;
 717         case STMT_CASE:
 718                 __merge_switches(top_expression(switch_expr_stack),
 719                                       stmt->case_expression);
 720                 __pass_case_to_client(top_expression(switch_expr_stack),
 721                                       stmt->case_expression);
 722                 if (!stmt->case_expression)
 723                         __set_default();
 724                 __split_expr(stmt->case_expression);
 725                 __split_expr(stmt->case_to);
 726                 __split_stmt(stmt->case_statement);
 727                 break;
 728         case STMT_LABEL:
 729                 if (stmt->label_identifier &&
 730                     stmt->label_identifier->type == SYM_LABEL &&
 731                     stmt->label_identifier->ident) {
 732                         loop_count = 1000000;
 733                         __merge_gotos(stmt->label_identifier->ident->name);
 734                 }
 735                 __split_stmt(stmt->label_statement);
 736                 break;
 737         case STMT_GOTO:
 738                 __split_expr(stmt->goto_expression);
 739                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 740                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 741                                 __process_breaks();
 742                         } else if (!strcmp(stmt->goto_label->ident->name,
 743                                            "continue")) {
 744                                 __process_continues();
 745                         }
 746                 } else if (stmt->goto_label &&
 747                            stmt->goto_label->type == SYM_LABEL &&
 748                            stmt->goto_label->ident) {
 749                         __save_gotos(stmt->goto_label->ident->name);
 750                 }
 751                 nullify_path();
 752                 break;
 753         case STMT_NONE:
 754                 break;
 755         case STMT_ASM:
 756                 __pass_to_client(stmt, ASM_HOOK);
 757                 __split_expr(stmt->asm_string);
 758                 split_asm_constraints(stmt->asm_outputs);
 759                 split_asm_constraints(stmt->asm_inputs);
 760                 split_asm_constraints(stmt->asm_clobbers);
 761                 break;
 762         case STMT_CONTEXT:
 763                 break;
 764         case STMT_RANGE:
 765                 __split_expr(stmt->range_expression);
 766                 __split_expr(stmt->range_low);
 767                 __split_expr(stmt->range_high);
 768                 break;
 769         }
 770 out:
 771         __process_post_op_stack();
 772 }
 773
 774 static void split_expr_list(struct expression_list *expr_list)
 775 {
 776         struct expression *expr;
 777
 778         FOR_EACH_PTR(expr_list, expr) {
 779                 __split_expr(expr);
 780                 __process_post_op_stack();
 781         } END_FOR_EACH_PTR(expr);
 782 }
 783
 784 static void split_sym(struct symbol *sym)
 785 {
 786         if (!sym)
 787                 return;
 788         if (!(sym->namespace & NS_SYMBOL))
 789                 return;
 790
 791         __split_stmt(sym->stmt);
 792         __split_expr(sym->array_size);
 793         split_symlist(sym->arguments);
 794         split_symlist(sym->symbol_list);
 795         __split_stmt(sym->inline_stmt);
 796         split_symlist(sym->inline_symbol_list);
 797 }
 798
 799 static void split_symlist(struct symbol_list *sym_list)
 800 {
 801         struct symbol *sym;
 802
 803         FOR_EACH_PTR(sym_list, sym) {
 804                 split_sym(sym);
 805         } END_FOR_EACH_PTR(sym);
 806 }
 807
 808 typedef void (fake_cb)(struct expression *expr);
 809
 810 static int member_to_number(struct expression *expr, struct ident *member)
 811 {
 812         struct symbol *type, *tmp;
 813         char *name;
 814         int i;
 815
 816         if (!member)
 817                 return -1;
 818         name = member->name;
 819
 820         type = get_type(expr);
 821         if (!type || type->type != SYM_STRUCT)
 822                 return -1;
 823
 824         i = -1;
 825         FOR_EACH_PTR(type->symbol_list, tmp) {
 826                 i++;
 827                 if (!tmp->ident)
 828                         continue;
 829                 if (strcmp(name, tmp->ident->name) == 0)
 830                         return i;
 831         } END_FOR_EACH_PTR(tmp);
 832         return -1;
 833 }
 834
 835 static struct ident *number_to_member(struct expression *expr, int num)
 836 {
 837         struct symbol *type, *member;
 838         int i = 0;
 839
 840         type = get_type(expr);
 841         if (!type || type->type != SYM_STRUCT)
 842                 return NULL;
 843
 844         FOR_EACH_PTR(type->symbol_list, member) {
 845                 if (i == num)
 846                         return member->ident;
 847                 i++;
 848         } END_FOR_EACH_PTR(member);
 849         return NULL;
 850 }
 851
 852 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb);
 853
 854 struct member_set {
 855         struct ident *ident;
 856         int set;
 857 };
 858
 859 static struct member_set *alloc_member_set(struct symbol *type)
 860 {
 861         struct member_set *member_set;
 862         struct symbol *member;
 863         int member_count;
 864         int member_idx;
 865
 866         member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 867         member_set = malloc(member_count * sizeof(*member_set));
 868         member_idx = 0;
 869         FOR_EACH_PTR(type->symbol_list, member) {
 870                 member_set[member_idx].ident = member->ident;
 871                 member_set[member_idx].set = 0;
 872                 member_idx++;
 873         } END_FOR_EACH_PTR(member);
 874
 875         return member_set;
 876 }
 877
 878 static void mark_member_as_set(struct symbol *type, struct member_set *member_set, struct ident *ident)
 879 {
 880         int member_count = ptr_list_size((struct ptr_list *)type->symbol_list);
 881         int i;
 882
 883         for (i = 0; i < member_count; i++) {
 884                 if (member_set[i].ident == ident) {
 885                         member_set[i].set = 1;
 886                         return;
 887                 }
 888         }
 889 //      crap.  this is buggy.
 890 //      sm_msg("internal smatch error in initializer %s.%s", type->ident->name, ident->name);
 891 }
 892
 893 static void set_unset_to_zero(struct expression *symbol, struct symbol *type, struct member_set *member_set)
 894 {
 895         struct expression *deref, *assign;
 896         struct symbol *member, *member_type;
 897         int member_idx;
 898
 899         member_idx = 0;
 900         FOR_EACH_PTR(type->symbol_list, member) {
 901                 if (!member->ident || member_set[member_idx].set) {
 902                         member_idx++;
 903                         continue;
 904                 }
 905                 member_type = get_real_base_type(member);
 906                 if (!member_type || member_type->type == SYM_ARRAY)
 907                         continue;
 908                 /* TODO: this should be handled recursively and not ignored */
 909                 if (member_type->type == SYM_STRUCT || member_type->type == SYM_UNION)
 910                         continue;
 911                 deref = member_expression(symbol, '.', member->ident);
 912                 assign = assign_expression(deref, zero_expr());
 913                 __split_expr(assign);
 914                 member_idx++;
 915         } END_FOR_EACH_PTR(member);
 916
 917 }
 918
 919 static void fake_member_assigns_helper(struct expression *symbol, struct expression_list *members, fake_cb *fake_cb)
 920 {
 921         struct expression *deref, *assign, *tmp;
 922         struct symbol *struct_type, *type;
 923         struct ident *member;
 924         int member_idx;
 925         struct member_set *member_set;
 926
 927         struct_type = get_type(symbol);
 928         if (!struct_type ||
 929             (struct_type->type != SYM_STRUCT && struct_type->type != SYM_UNION))
 930                 return;
 931
 932         member_set = alloc_member_set(struct_type);
 933
 934         member_idx = 0;
 935         FOR_EACH_PTR(members, tmp) {
 936                 member = number_to_member(symbol, member_idx);
 937                 while (tmp->type == EXPR_IDENTIFIER) {
 938                         member = tmp->expr_ident;
 939                         member_idx = member_to_number(symbol, member);
 940                         tmp = tmp->ident_expression;
 941                 }
 942                 mark_member_as_set(struct_type, member_set, member);
 943                 member_idx++;
 944                 deref = member_expression(symbol, '.', member);
 945                 if (tmp->type == EXPR_INITIALIZER) {
 946                         type = get_type(deref);
 947                         if (type && type->type == SYM_ARRAY)
 948                                 fake_element_assigns_helper(deref, tmp->expr_list, fake_cb);
 949                         else
 950                                 fake_member_assigns_helper(deref, tmp->expr_list, fake_cb);
 951                 } else {
 952                         assign = assign_expression(deref, tmp);
 953                         fake_cb(assign);
 954                 }
 955         } END_FOR_EACH_PTR(tmp);
 956
 957         set_unset_to_zero(symbol, struct_type, member_set);
 958 }
 959
 960 static void fake_member_assigns(struct symbol *sym, fake_cb *fake_cb)
 961 {
 962         fake_member_assigns_helper(symbol_expression(sym),
 963                                    sym->initializer->expr_list, fake_cb);
 964 }
 965
 966 static void fake_element_assigns_helper(struct expression *array, struct expression_list *expr_list, fake_cb *fake_cb)
 967 {
 968         struct expression *offset, *binop, *assign, *tmp;
 969         struct symbol *type;
 970         int idx;
 971
 972         idx = 0;
 973         FOR_EACH_PTR(expr_list, tmp) {
 974                 if (tmp->type == EXPR_INDEX) {
 975                         if (tmp->idx_from != tmp->idx_to)
 976                                 return;
 977                         idx = tmp->idx_from;
 978                         if (!tmp->idx_expression)
 979                                 goto next;
 980                         tmp = tmp->idx_expression;
 981                 }
 982                 offset = value_expr(idx);
 983                 binop = array_element_expression(array, offset);
 984                 if (tmp->type == EXPR_INITIALIZER) {
 985                         type = get_type(binop);
 986                         if (type && type->type == SYM_ARRAY)
 987                                 fake_element_assigns_helper(binop, tmp->expr_list, fake_cb);
 988                         else
 989                                 fake_member_assigns_helper(binop, tmp->expr_list, fake_cb);
 990                 } else {
 991                         assign = assign_expression(binop, tmp);
 992                         fake_cb(assign);
 993                 }
 994 next:
 995                 idx++;
 996         } END_FOR_EACH_PTR(tmp);
 997 }
 998
 999 static void fake_element_assigns(struct symbol *sym, fake_cb *fake_cb)
1000 {
1001         fake_element_assigns_helper(symbol_expression(sym), sym->initializer->expr_list, fake_cb);
1002 }
1003
1004 static void fake_assign_expr(struct symbol *sym)
1005 {
1006         struct expression *assign, *symbol;
1007
1008         symbol = symbol_expression(sym);
1009         assign = assign_expression(symbol, sym->initializer);
1010         __split_expr(assign);
1011 }
1012
1013 static void call_split_expr(struct expression *expr)
1014 {
1015         __split_expr(expr);
1016 }
1017
1018 static void do_initializer_stuff(struct symbol *sym)
1019 {
1020         if (!sym->initializer)
1021                 return;
1022
1023         if (sym->initializer->type == EXPR_INITIALIZER) {
1024                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1025                         fake_element_assigns(sym, call_split_expr);
1026                 else
1027                         fake_member_assigns(sym, call_split_expr);
1028         } else {
1029                 fake_assign_expr(sym);
1030         }
1031 }
1032
1033 static void split_declaration(struct symbol_list *sym_list)
1034 {
1035         struct symbol *sym;
1036
1037         FOR_EACH_PTR(sym_list, sym) {
1038                 __pass_to_client(sym, DECLARATION_HOOK);
1039                 do_initializer_stuff(sym);
1040                 split_sym(sym);
1041         } END_FOR_EACH_PTR(sym);
1042 }
1043
1044 static void call_global_assign_hooks(struct expression *assign)
1045 {
1046         __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1047 }
1048
1049 static void fake_global_assign(struct symbol *sym)
1050 {
1051         struct expression *assign, *symbol;
1052
1053         if (!sym->initializer)
1054                 return;
1055         if (sym->initializer->type == EXPR_INITIALIZER) {
1056                 if (get_real_base_type(sym)->type == SYM_ARRAY)
1057                         fake_element_assigns(sym, call_global_assign_hooks);
1058                 else
1059                         fake_member_assigns(sym, call_global_assign_hooks);
1060         } else {
1061                 symbol = symbol_expression(sym);
1062                 assign = assign_expression(symbol, sym->initializer);
1063                 __pass_to_client(assign, GLOBAL_ASSIGNMENT_HOOK);
1064         }
1065 }
1066
1067 static void start_function_definition(struct symbol *sym)
1068 {
1069         __in_function_def = 1;
1070         __pass_to_client(sym, FUNC_DEF_HOOK);
1071         __in_function_def = 0;
1072         __pass_to_client(sym, AFTER_DEF_HOOK);
1073
1074 }
1075
1076 static void split_function(struct symbol *sym)
1077 {
1078         struct symbol *base_type = get_base_type(sym);
1079
1080         cur_func_sym = sym;
1081         if (sym->ident)
1082                 cur_func = sym->ident->name;
1083         __smatch_lineno = sym->pos.line;
1084         last_stmt = NULL;
1085         loop_count = 0;
1086         sm_debug("new function:  %s\n", cur_func);
1087         __slist_id = 0;
1088         if (option_two_passes) {
1089                 __unnullify_path();
1090                 loop_num = 0;
1091                 final_pass = 0;
1092                 start_function_definition(sym);
1093                 __split_stmt(base_type->stmt);
1094                 __split_stmt(base_type->inline_stmt);
1095                 nullify_path();
1096         }
1097         __unnullify_path();
1098         loop_num = 0;
1099         start_function_definition(sym);
1100         __split_stmt(base_type->stmt);
1101         __split_stmt(base_type->inline_stmt);
1102         __pass_to_client(sym, END_FUNC_HOOK);
1103         __pass_to_client(sym, AFTER_FUNC_HOOK);
1104         cur_func_sym = NULL;
1105         cur_func = NULL;
1106         clear_all_states();
1107         free_data_info_allocs();
1108         free_expression_stack(&switch_expr_stack);
1109         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1110         __bail_on_rest_of_function = 0;
1111 }
1112
1113 static void parse_inline(struct expression *call)
1114 {
1115         struct symbol *base_type;
1116         int loop_num_bak = loop_num;
1117         int final_pass_bak = final_pass;
1118         char *cur_func_bak = cur_func;
1119         struct statement_list *big_statement_stack_bak = big_statement_stack;
1120         struct expression_list *big_expression_stack_bak = big_expression_stack;
1121         struct expression_list *switch_expr_stack_bak = switch_expr_stack;
1122         struct symbol *cur_func_sym_bak = cur_func_sym;
1123
1124         __pass_to_client(call, INLINE_FN_START);
1125         final_pass = 0;  /* don't print anything */
1126         __inline_fn = call;
1127
1128         base_type = get_base_type(call->fn->symbol);
1129         cur_func_sym = call->fn->symbol;
1130         if (call->fn->symbol->ident)
1131                 cur_func = call->fn->symbol->ident->name;
1132         else
1133                 cur_func = NULL;
1134         set_position(call->fn->symbol->pos);
1135
1136         save_all_states();
1137         nullify_all_states();
1138         big_statement_stack = NULL;
1139         big_expression_stack = NULL;
1140         switch_expr_stack = NULL;
1141
1142         sm_debug("inline function:  %s\n", cur_func);
1143         __unnullify_path();
1144         loop_num = 0;
1145         start_function_definition(call->fn->symbol);
1146         __split_stmt(base_type->stmt);
1147         __split_stmt(base_type->inline_stmt);
1148         __pass_to_client(call->fn->symbol, END_FUNC_HOOK);
1149         __pass_to_client(call->fn->symbol, AFTER_FUNC_HOOK);
1150
1151         free_expression_stack(&switch_expr_stack);
1152         __free_ptr_list((struct ptr_list **)&big_statement_stack);
1153         nullify_path();
1154
1155         loop_num = loop_num_bak;
1156         final_pass = final_pass_bak;
1157         cur_func_sym = cur_func_sym_bak;
1158         cur_func = cur_func_bak;
1159         big_statement_stack = big_statement_stack_bak;
1160         big_expression_stack = big_expression_stack_bak;
1161         switch_expr_stack = switch_expr_stack_bak;
1162
1163         restore_all_states();
1164         set_position(call->pos);
1165         __inline_fn = NULL;
1166         __pass_to_client(call, INLINE_FN_END);
1167 }
1168
1169 static struct symbol_list *inlines_called;
1170 static void add_inline_function(struct symbol *sym)
1171 {
1172         static struct symbol_list *already_added;
1173         struct symbol *tmp;
1174
1175         FOR_EACH_PTR(already_added, tmp) {
1176                 if (tmp == sym)
1177                         return;
1178         } END_FOR_EACH_PTR(tmp);
1179
1180         add_ptr_list(&already_added, sym);
1181         add_ptr_list(&inlines_called, sym);
1182 }
1183
1184 static void process_inlines()
1185 {
1186         struct symbol *tmp;
1187
1188         FOR_EACH_PTR(inlines_called, tmp) {
1189                 split_function(tmp);
1190         } END_FOR_EACH_PTR(tmp);
1191         free_ptr_list(&inlines_called);
1192 }
1193
1194 static struct symbol *get_last_scoped_symbol(struct symbol_list *big_list, int use_static)
1195 {
1196         struct symbol *sym;
1197
1198         FOR_EACH_PTR_REVERSE(big_list, sym) {
1199                 if (!sym->scope)
1200                         continue;
1201                 if (use_static && sym->ctype.modifiers & MOD_STATIC)
1202                         return sym;
1203                 if (!use_static && !(sym->ctype.modifiers & MOD_STATIC))
1204                         return sym;
1205         } END_FOR_EACH_PTR_REVERSE(sym);
1206
1207         return NULL;
1208 }
1209
1210 static void split_inlines_in_scope(struct symbol *sym)
1211 {
1212         struct symbol *base;
1213         struct symbol_list *scope_list;
1214         int stream;
1215
1216         scope_list = sym->scope->symbols;
1217         stream = sym->pos.stream;
1218
1219         /* find the last static symbol in the file */
1220         FOR_EACH_PTR_REVERSE(scope_list, sym) {
1221                 if (sym->pos.stream != stream)
1222                         continue;
1223                 if (sym->type != SYM_NODE)
1224                         continue;
1225                 base = get_base_type(sym);
1226                 if (!base)
1227                         continue;
1228                 if (base->type != SYM_FN)
1229                         continue;
1230                 if (!base->inline_stmt)
1231                         continue;
1232                 add_inline_function(sym);
1233         } END_FOR_EACH_PTR_REVERSE(sym);
1234
1235         process_inlines();
1236 }
1237
1238 static void split_inlines(struct symbol_list *sym_list)
1239 {
1240         struct symbol *sym;
1241
1242         sym = get_last_scoped_symbol(sym_list, 0);
1243         if (sym)
1244                 split_inlines_in_scope(sym);
1245         sym = get_last_scoped_symbol(sym_list, 1);
1246         if (sym)
1247                 split_inlines_in_scope(sym);
1248 }
1249
1250 static void split_functions(struct symbol_list *sym_list)
1251 {
1252         struct symbol *sym;
1253
1254         FOR_EACH_PTR(sym_list, sym) {
1255                 set_position(sym->pos);
1256                 if (sym->type == SYM_NODE && get_base_type(sym)->type == SYM_FN) {
1257                         split_function(sym);
1258                         process_inlines();
1259                 } else {
1260                         __pass_to_client(sym, BASE_HOOK);
1261                         fake_global_assign(sym);
1262                 }
1263         } END_FOR_EACH_PTR(sym);
1264         split_inlines(sym_list);
1265         __pass_to_client(sym_list, END_FILE_HOOK);
1266 }
1267
1268 void smatch(int argc, char **argv)
1269 {
1270
1271         struct string_list *filelist = NULL;
1272         struct symbol_list *sym_list;
1273
1274         if (argc < 2) {
1275                 printf("Usage:  smatch [--debug] <filename.c>\n");
1276                 exit(1);
1277         }
1278         sparse_initialize(argc, argv, &filelist);
1279         FOR_EACH_PTR_NOTAG(filelist, base_file) {
1280                 if (option_file_output) {
1281                         char buf[256];
1282
1283                         snprintf(buf, sizeof(buf), "%s.smatch", base_file);
1284                         sm_outfd = fopen(buf, "w");
1285                         if (!sm_outfd) {
1286                                 printf("Error:  Cannot open %s\n", base_file);
1287                                 exit(1);
1288                         }
1289                 }
1290                 sym_list = sparse_keep_tokens(base_file);
1291                 split_functions(sym_list);
1292         } END_FOR_EACH_PTR_NOTAG(base_file);
1293 }