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