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