smatch_flow.c

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