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