smatch_conditions.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 /*
  19  * The simplest type of condition is
  20  * if (a) { ...
  21  *
  22  * The next simplest kind of conditions is
  23  * if (a && b) { c;
  24  * In that case 'a' is true when we get to 'b' and both are true
  25  * when we get to c.
  26  *
  27  * Or's are a little more complicated.
  28  * if (a || b) { c;
  29  * We know 'a' is not true when we get to 'b' but it may be true
  30  * when we get to c.
  31  *
  32  * If we mix and's and or's that's even more complicated.
  33  * if (a && b && c || a && d) { d ;
  34  * 'a' is true when we evaluate 'b', and 'd'.
  35  * 'b' is true when we evaluate 'c' but otherwise we don't.
  36  *
  37  * The other thing that complicates matters is if we negate
  38  * some if conditions.
  39  * if (!a) { ...
  40  * Smatch has passes the un-negated version to the client and flip
  41  * the true and false values internally.  This makes it easier
  42  * to write checks.
  43  *
  44  * And negations can be part of a compound.
  45  * if (a && !(b || c)) { d;
  46  * In that situation we multiply the negative through to simplify
  47  * stuff so that we can remove the parens like this:
  48  * if (a && !b && !c) { d;
  49  *
  50  * One other thing is that:
  51  * if ((a) != 0){ ...
  52  * that's basically the same as testing for just 'a' and we simplify
  53  * comparisons with zero before passing it to the script.
  54  *
  55  */
  56
  57 #include "smatch.h"
  58 #include "smatch_slist.h"
  59 #include "smatch_extra.h"
  60 #include "smatch_expression_stacks.h"
  61
  62 extern int __expr_stmt_count;
  63
  64 struct expression_list *big_condition_stack;
  65
  66 static void split_conditions(struct expression *expr);
  67
  68 static int is_logical_and(struct expression *expr)
  69 {
  70         if (expr->op == SPECIAL_LOGICAL_AND)
  71                 return 1;
  72         return 0;
  73 }
  74
  75 static int handle_zero_comparisons(struct expression *expr)
  76 {
  77         struct expression *tmp = NULL;
  78         struct expression *zero;
  79
  80         // if left is zero or right is zero
  81         if (expr_is_zero(expr->left)) {
  82                 zero = strip_expr(expr->left);
  83                 if (zero->type != EXPR_VALUE)
  84                         __split_expr(expr->left);
  85                 tmp = expr->right;
  86         } else if (expr_is_zero(expr->right)) {
  87                 zero = strip_expr(expr->left);
  88                 if (zero->type != EXPR_VALUE)
  89                         __split_expr(expr->right);
  90                 tmp = expr->left;
  91         } else {
  92                 return 0;
  93         }
  94
  95         // "if (foo != 0)" is the same as "if (foo)"
  96         if (expr->op == SPECIAL_NOTEQUAL) {
  97                 split_conditions(tmp);
  98                 return 1;
  99         }
 100
 101         // "if (foo == 0)" is the same as "if (!foo)"
 102         if (expr->op == SPECIAL_EQUAL) {
 103                 split_conditions(tmp);
 104                 __negate_cond_stacks();
 105                 return 1;
 106         }
 107
 108         return 0;
 109 }
 110
 111 /*
 112  * This function is for handling calls to likely/unlikely
 113  */
 114
 115 static int ignore_builtin_expect(struct expression *expr)
 116 {
 117         if (sym_name_is("__builtin_expect", expr->fn)) {
 118                 split_conditions(first_ptr_list((struct ptr_list *) expr->args));
 119                 return 1;
 120         }
 121         return 0;
 122 }
 123
 124 /*
 125  * handle_compound_stmt() is for: foo = ({blah; blah; blah; 1})
 126  */
 127
 128 static void handle_compound_stmt(struct statement *stmt)
 129 {
 130         struct expression *expr = NULL;
 131         struct statement *last;
 132         struct statement *s;
 133
 134         last = last_ptr_list((struct ptr_list *)stmt->stmts);
 135         if (last->type == STMT_LABEL) {
 136                 if (last->label_statement &&
 137                     last->label_statement->type == STMT_EXPRESSION)
 138                         expr = last->label_statement->expression;
 139                 else
 140                         last = NULL;
 141         } else if (last->type != STMT_EXPRESSION) {
 142                 last = NULL;
 143         } else {
 144                 expr = last->expression;
 145         }
 146
 147         FOR_EACH_PTR(stmt->stmts, s) {
 148                 if (s != last)
 149                         __split_stmt(s);
 150         } END_FOR_EACH_PTR(s);
 151         if (last && last->type == STMT_LABEL)
 152                 __split_label_stmt(last);
 153         split_conditions(expr);
 154 }
 155
 156 static int handle_preop(struct expression *expr)
 157 {
 158         struct statement *stmt;
 159
 160         if (expr->op == '!') {
 161                 split_conditions(expr->unop);
 162                 __negate_cond_stacks();
 163                 return 1;
 164         }
 165         stmt = get_expression_statement(expr);
 166         if (stmt) {
 167                 handle_compound_stmt(stmt);
 168                 return 1;
 169         }
 170         return 0;
 171 }
 172
 173 static void handle_logical(struct expression *expr)
 174 {
 175         /*
 176          * If we come to an "and" expr then:
 177          * We split the left side.
 178          * We keep all the current states.
 179          * We split the right side.
 180          * We keep all the states from both true sides.
 181          *
 182          * If it's an "or" expr then:
 183          * We save the current slist.
 184          * We split the left side.
 185          * We use the false states for the right side.
 186          * We split the right side.
 187          * We save all the states that are the same on both sides.
 188          */
 189
 190         split_conditions(expr->left);
 191
 192         if (is_logical_and(expr))
 193                 __use_cond_true_states();
 194         else
 195                 __use_cond_false_states();
 196
 197         __push_cond_stacks();
 198
 199         __save_pre_cond_states();
 200         split_conditions(expr->right);
 201         __discard_pre_cond_states();
 202
 203         if (is_logical_and(expr))
 204                 __and_cond_states();
 205         else
 206                 __or_cond_states();
 207
 208         __use_cond_true_states();
 209 }
 210
 211 static struct stree *combine_strees(struct stree *orig, struct stree *fake, struct stree *new)
 212 {
 213         struct stree *ret = NULL;
 214
 215         overwrite_stree(orig, &ret);
 216         overwrite_stree(fake, &ret);
 217         overwrite_stree(new, &ret);
 218         free_stree(&new);
 219
 220         return ret;
 221 }
 222
 223 /*
 224  * handle_select()
 225  * if ((aaa()?bbb():ccc())) { ...
 226  *
 227  * This is almost the same as:
 228  * if ((aaa() && bbb()) || (!aaa() && ccc())) { ...
 229  *
 230  * It's a bit complicated because we shouldn't pass aaa()
 231  * to the clients more than once.
 232  */
 233
 234 static void handle_select(struct expression *expr)
 235 {
 236         struct stree *a_T = NULL;
 237         struct stree *a_F = NULL;
 238         struct stree *a_T_b_T = NULL;
 239         struct stree *a_T_b_F = NULL;
 240         struct stree *a_T_b_fake = NULL;
 241         struct stree *a_F_c_T = NULL;
 242         struct stree *a_F_c_F = NULL;
 243         struct stree *a_F_c_fake = NULL;
 244         struct stree *tmp;
 245         struct sm_state *sm;
 246
 247         /*
 248          * Imagine we have this:  if (a ? b : c) { ...
 249          *
 250          * The condition is true if "a" is true and "b" is true or
 251          * "a" is false and "c" is true.  It's false if "a" is true
 252          * and "b" is false or "a" is false and "c" is false.
 253          *
 254          * The variable name "a_T_b_T" stands for "a true b true" etc.
 255          *
 256          * But if we know "b" is true then we can simpilify things.
 257          * The condition is true if "a" is true or if "a" is false and
 258          * "c" is true.  The only way the condition can be false is if
 259          * "a" is false and "c" is false.
 260          *
 261          * The remaining thing is the "a_T_b_fake".  When we simplify
 262          * the equations we have to take into consideration that other
 263          * states may have changed that don't play into the true false
 264          * equation.  Take the following example:
 265          * if ({
 266          *         (flags) = __raw_local_irq_save();
 267          *         _spin_trylock(lock) ? 1 :
 268          *                 ({ raw_local_irq_restore(flags);  0; });
 269          *    })
 270          * Smatch has to record that the irq flags were restored on the
 271          * false path.
 272          *
 273          */
 274
 275         __save_pre_cond_states();
 276
 277         split_conditions(expr->conditional);
 278
 279         a_T = __copy_cond_true_states();
 280         a_F = __copy_cond_false_states();
 281
 282         __use_cond_true_states();
 283
 284         __push_cond_stacks();
 285         __push_fake_cur_stree();
 286         split_conditions(expr->cond_true);
 287         __process_post_op_stack();
 288         a_T_b_fake = __pop_fake_cur_stree();
 289         a_T_b_T = combine_strees(a_T, a_T_b_fake, __pop_cond_true_stack());
 290         a_T_b_F = combine_strees(a_T, a_T_b_fake, __pop_cond_false_stack());
 291
 292         __use_cond_false_states();
 293
 294         __push_cond_stacks();
 295         __push_fake_cur_stree();
 296         split_conditions(expr->cond_false);
 297         a_F_c_fake = __pop_fake_cur_stree();
 298         a_F_c_T = combine_strees(a_F, a_F_c_fake, __pop_cond_true_stack());
 299         a_F_c_F = combine_strees(a_F, a_F_c_fake, __pop_cond_false_stack());
 300
 301         /* We have to restore the pre condition states so that
 302            implied_condition_true() will use the right cur_stree */
 303         __use_pre_cond_states();
 304
 305         if (implied_condition_true(expr->cond_true)) {
 306                 free_stree(&a_T_b_T);
 307                 free_stree(&a_T_b_F);
 308                 a_T_b_T = clone_stree(a_T);
 309                 overwrite_stree(a_T_b_fake, &a_T_b_T);
 310         }
 311         if (implied_condition_false(expr->cond_true)) {
 312                 free_stree(&a_T_b_T);
 313                 free_stree(&a_T_b_F);
 314                 a_T_b_F = clone_stree(a_T);
 315                 overwrite_stree(a_T_b_fake, &a_T_b_F);
 316         }
 317         if (implied_condition_true(expr->cond_false)) {
 318                 free_stree(&a_F_c_T);
 319                 free_stree(&a_F_c_F);
 320                 a_F_c_T = clone_stree(a_F);
 321                 overwrite_stree(a_F_c_fake, &a_F_c_T);
 322         }
 323         if (implied_condition_false(expr->cond_false)) {
 324                 free_stree(&a_F_c_T);
 325                 free_stree(&a_F_c_F);
 326                 a_F_c_F = clone_stree(a_F);
 327                 overwrite_stree(a_F_c_fake, &a_F_c_F);
 328         }
 329
 330         merge_stree(&a_T_b_T, a_F_c_T);
 331         merge_stree(&a_T_b_F, a_F_c_F);
 332
 333         tmp = __pop_cond_true_stack();
 334         free_stree(&tmp);
 335         tmp = __pop_cond_false_stack();
 336         free_stree(&tmp);
 337
 338         __push_cond_stacks();
 339         FOR_EACH_SM(a_T_b_T, sm) {
 340                 __set_true_false_sm(sm, NULL);
 341         } END_FOR_EACH_SM(sm);
 342         FOR_EACH_SM(a_T_b_F, sm) {
 343                 __set_true_false_sm(NULL, sm);
 344         } END_FOR_EACH_SM(sm);
 345         __free_set_states();
 346
 347         free_stree(&a_T_b_fake);
 348         free_stree(&a_F_c_fake);
 349         free_stree(&a_F_c_T);
 350         free_stree(&a_F_c_F);
 351         free_stree(&a_T_b_T);
 352         free_stree(&a_T_b_F);
 353         free_stree(&a_T);
 354         free_stree(&a_F);
 355 }
 356
 357 static void handle_comma(struct expression *expr)
 358 {
 359         __split_expr(expr->left);
 360         split_conditions(expr->right);
 361 }
 362
 363 static int make_op_unsigned(int op)
 364 {
 365         switch (op) {
 366         case '<':
 367                 return SPECIAL_UNSIGNED_LT;
 368         case SPECIAL_LTE:
 369                 return SPECIAL_UNSIGNED_LTE;
 370         case '>':
 371                 return SPECIAL_UNSIGNED_GT;
 372         case SPECIAL_GTE:
 373                 return SPECIAL_UNSIGNED_GTE;
 374         }
 375         return op;
 376 }
 377
 378 static void hackup_unsigned_compares(struct expression *expr)
 379 {
 380         if (expr->type != EXPR_COMPARE)
 381                 return;
 382
 383         if (type_unsigned(get_type(expr)))
 384                 expr->op = make_op_unsigned(expr->op);
 385 }
 386
 387 static void do_condition(struct expression *expr)
 388 {
 389         __fold_in_set_states();
 390         __push_fake_cur_stree();
 391         __pass_to_client(expr, CONDITION_HOOK);
 392         __fold_in_set_states();
 393 }
 394
 395 static void split_conditions(struct expression *expr)
 396 {
 397         if (option_debug) {
 398                 char *cond = expr_to_str(expr);
 399
 400                 sm_msg("%d in split_conditions (%s)", get_lineno(), cond);
 401                 free_string(cond);
 402         }
 403
 404         expr = strip_expr_set_parent(expr);
 405         if (!expr) {
 406                 __fold_in_set_states();
 407                 return;
 408         }
 409
 410         /*
 411          * On fast paths (and also I guess some people think it's cool) people
 412          * sometimes use | instead of ||.  It works the same basically except
 413          * that || implies a memory barrier between conditions.  The easiest way
 414          * to handle it is by pretending that | also has a barrier and re-using
 415          * all the normal condition code.  This potentially hides some bugs, but
 416          * people who write code like this should just be careful or they
 417          * deserve bugs.
 418          *
 419          * We could potentially treat boolean bitwise & this way but that seems
 420          * too complicated to deal with.
 421          */
 422         if (expr->type == EXPR_BINOP && expr->op == '|') {
 423                 expr_set_parent_expr(expr->left, expr);
 424                 expr_set_parent_expr(expr->right, expr);
 425                 handle_logical(expr);
 426                 return;
 427         }
 428
 429         switch (expr->type) {
 430         case EXPR_LOGICAL:
 431                 expr_set_parent_expr(expr->left, expr);
 432                 expr_set_parent_expr(expr->right, expr);
 433                 __pass_to_client(expr, LOGIC_HOOK);
 434                 handle_logical(expr);
 435                 return;
 436         case EXPR_COMPARE:
 437                 expr_set_parent_expr(expr->left, expr);
 438                 expr_set_parent_expr(expr->right, expr);
 439                 hackup_unsigned_compares(expr);
 440                 if (handle_zero_comparisons(expr))
 441                         return;
 442                 break;
 443         case EXPR_CALL:
 444                 if (ignore_builtin_expect(expr))
 445                         return;
 446                 break;
 447         case EXPR_PREOP:
 448                 expr_set_parent_expr(expr->unop, expr);
 449                 if (handle_preop(expr))
 450                         return;
 451                 break;
 452         case EXPR_CONDITIONAL:
 453         case EXPR_SELECT:
 454                 expr_set_parent_expr(expr->conditional, expr);
 455                 expr_set_parent_expr(expr->cond_true, expr);
 456                 expr_set_parent_expr(expr->cond_false, expr);
 457                 handle_select(expr);
 458                 return;
 459         case EXPR_COMMA:
 460                 expr_set_parent_expr(expr->left, expr);
 461                 expr_set_parent_expr(expr->right, expr);
 462                 handle_comma(expr);
 463                 return;
 464         }
 465
 466         /* fixme: this should be in smatch_flow.c
 467            but because of the funny stuff we do with conditions
 468            it's awkward to put it there.  We would need to
 469            call CONDITION_HOOK in smatch_flow as well.
 470         */
 471         push_expression(&big_expression_stack, expr);
 472         push_expression(&big_condition_stack, expr);
 473
 474         if (expr->type == EXPR_COMPARE) {
 475                 if (expr->left->type != EXPR_POSTOP)
 476                         __split_expr(expr->left);
 477                 if (expr->right->type != EXPR_POSTOP)
 478                         __split_expr(expr->right);
 479         } else if (expr->type != EXPR_POSTOP) {
 480                 __split_expr(expr);
 481         }
 482         do_condition(expr);
 483         if (expr->type == EXPR_COMPARE) {
 484                 if (expr->left->type == EXPR_POSTOP)
 485                         __split_expr(expr->left);
 486                 if (expr->right->type == EXPR_POSTOP)
 487                         __split_expr(expr->right);
 488         } else if (expr->type == EXPR_POSTOP) {
 489                 __split_expr(expr);
 490         }
 491         __push_fake_cur_stree();
 492         __process_post_op_stack();
 493         __fold_in_set_states();
 494         pop_expression(&big_condition_stack);
 495         pop_expression(&big_expression_stack);
 496 }
 497
 498 static int inside_condition;
 499 void __split_whole_condition(struct expression *expr)
 500 {
 501         sm_debug("%d in __split_whole_condition\n", get_lineno());
 502         inside_condition++;
 503         __save_pre_cond_states();
 504         __push_cond_stacks();
 505         /* it's a hack, but it's sometimes handy to have this stuff
 506            on the big_expression_stack.  */
 507         push_expression(&big_expression_stack, expr);
 508         split_conditions(expr);
 509         __use_cond_states();
 510         __pass_to_client(expr, WHOLE_CONDITION_HOOK);
 511         pop_expression(&big_expression_stack);
 512         inside_condition--;
 513         sm_debug("%d done __split_whole_condition\n", get_lineno());
 514 }
 515
 516 void __handle_logic(struct expression *expr)
 517 {
 518         sm_debug("%d in __handle_logic\n", get_lineno());
 519         inside_condition++;
 520         __save_pre_cond_states();
 521         __push_cond_stacks();
 522         /* it's a hack, but it's sometimes handy to have this stuff
 523            on the big_expression_stack.  */
 524         push_expression(&big_expression_stack, expr);
 525         if (expr)
 526                 split_conditions(expr);
 527         __use_cond_states();
 528         __pass_to_client(expr, WHOLE_CONDITION_HOOK);
 529         pop_expression(&big_expression_stack);
 530         __merge_false_states();
 531         inside_condition--;
 532         sm_debug("%d done __handle_logic\n", get_lineno());
 533 }
 534
 535 int is_condition(struct expression *expr)
 536 {
 537
 538         expr = strip_expr(expr);
 539         if (!expr)
 540                 return 0;
 541
 542         switch (expr->type) {
 543         case EXPR_LOGICAL:
 544         case EXPR_COMPARE:
 545                 return 1;
 546         case EXPR_PREOP:
 547                 if (expr->op == '!')
 548                         return 1;
 549         }
 550         return 0;
 551 }
 552
 553 int __handle_condition_assigns(struct expression *expr)
 554 {
 555         struct expression *right;
 556         struct stree *true_stree, *false_stree, *fake_stree;
 557         struct sm_state *sm;
 558
 559         if (expr->op != '=')
 560                 return 0;
 561         right = strip_expr(expr->right);
 562         if (!is_condition(expr->right))
 563                 return 0;
 564
 565         sm_debug("%d in __handle_condition_assigns\n", get_lineno());
 566         inside_condition++;
 567         __save_pre_cond_states();
 568         __push_cond_stacks();
 569         /* it's a hack, but it's sometimes handy to have this stuff
 570            on the big_expression_stack.  */
 571         push_expression(&big_expression_stack, right);
 572         split_conditions(right);
 573         true_stree = __get_true_states();
 574         false_stree = __get_false_states();
 575         __use_cond_states();
 576         __push_fake_cur_stree();
 577         set_extra_expr_mod(expr->left, alloc_estate_sval(sval_type_val(get_type(expr->left), 1)));
 578         __pass_to_client(right, WHOLE_CONDITION_HOOK);
 579
 580         fake_stree = __pop_fake_cur_stree();
 581         FOR_EACH_SM(fake_stree, sm) {
 582                 overwrite_sm_state_stree(&true_stree, sm);
 583         } END_FOR_EACH_SM(sm);
 584         free_stree(&fake_stree);
 585
 586         pop_expression(&big_expression_stack);
 587         inside_condition--;
 588
 589         __push_true_states();
 590
 591         __use_false_states();
 592         __push_fake_cur_stree();
 593         set_extra_expr_mod(expr->left, alloc_estate_sval(sval_type_val(get_type(expr->left), 0)));
 594
 595         fake_stree = __pop_fake_cur_stree();
 596         FOR_EACH_SM(fake_stree, sm) {
 597                 overwrite_sm_state_stree(&false_stree, sm);
 598         } END_FOR_EACH_SM(sm);
 599         free_stree(&fake_stree);
 600
 601         __merge_true_states();
 602         merge_fake_stree(&true_stree, false_stree);
 603         free_stree(&false_stree);
 604         FOR_EACH_SM(true_stree, sm) {
 605                 __set_sm(sm);
 606         } END_FOR_EACH_SM(sm);
 607
 608         __pass_to_client(expr, ASSIGNMENT_HOOK);
 609         sm_debug("%d done __handle_condition_assigns\n", get_lineno());
 610         return 1;
 611 }
 612
 613 static int is_select_assign(struct expression *expr)
 614 {
 615         struct expression *right;
 616
 617         if (expr->op != '=')
 618                 return 0;
 619         right = strip_expr(expr->right);
 620         if (right->type == EXPR_CONDITIONAL)
 621                 return 1;
 622         if (right->type == EXPR_SELECT)
 623                 return 1;
 624         return 0;
 625 }
 626
 627 int __handle_select_assigns(struct expression *expr)
 628 {
 629         struct expression *right;
 630         struct stree *final_states = NULL;
 631         struct sm_state *sm;
 632         int is_true;
 633         int is_false;
 634
 635         if (!is_select_assign(expr))
 636                 return 0;
 637         sm_debug("%d in __handle_ternary_assigns\n", get_lineno());
 638         right = strip_expr(expr->right);
 639         __pass_to_client(right, SELECT_HOOK);
 640
 641         is_true = implied_condition_true(right->conditional);
 642         is_false = implied_condition_false(right->conditional);
 643
 644         /* hah hah.  the ultra fake out */
 645         __save_pre_cond_states();
 646         __split_whole_condition(right->conditional);
 647
 648         if (!is_false) {
 649                 struct expression *fake_expr;
 650
 651                 if (right->cond_true)
 652                         fake_expr = assign_expression(expr->left, expr->op, right->cond_true);
 653                 else
 654                         fake_expr = assign_expression(expr->left, expr->op, right->conditional);
 655                 __split_expr(fake_expr);
 656                 final_states = clone_stree(__get_cur_stree());
 657         }
 658
 659         __use_false_states();
 660         if (!is_true) {
 661                 struct expression *fake_expr;
 662
 663                 fake_expr = assign_expression(expr->left, expr->op, right->cond_false);
 664                 __split_expr(fake_expr);
 665                 merge_stree(&final_states, __get_cur_stree());
 666         }
 667
 668         __use_pre_cond_states();
 669
 670         FOR_EACH_SM(final_states, sm) {
 671                 __set_sm(sm);
 672         } END_FOR_EACH_SM(sm);
 673
 674         free_stree(&final_states);
 675
 676         sm_debug("%d done __handle_ternary_assigns\n", get_lineno());
 677
 678         return 1;
 679 }
 680
 681 static struct statement *split_then_return_last(struct statement *stmt)
 682 {
 683         struct statement *tmp;
 684         struct statement *last_stmt;
 685
 686         last_stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 687         if (!last_stmt)
 688                 return NULL;
 689
 690         __push_scope_hooks();
 691         FOR_EACH_PTR(stmt->stmts, tmp) {
 692                 if (tmp == last_stmt) {
 693                         if (tmp->type == STMT_LABEL) {
 694                                 __split_label_stmt(tmp);
 695                                 return tmp->label_statement;
 696                         }
 697                         return last_stmt;
 698                 }
 699                 __split_stmt(tmp);
 700         } END_FOR_EACH_PTR(tmp);
 701         return NULL;
 702 }
 703
 704 int __handle_expr_statement_assigns(struct expression *expr)
 705 {
 706         struct expression *right;
 707         struct statement *stmt;
 708
 709         right = expr->right;
 710         if (right->type == EXPR_PREOP && right->op == '(')
 711                 right = right->unop;
 712         if (right->type != EXPR_STATEMENT)
 713                 return 0;
 714
 715         __expr_stmt_count++;
 716         stmt = right->statement;
 717         if (stmt->type == STMT_COMPOUND) {
 718                 struct statement *last_stmt;
 719                 struct expression *fake_assign;
 720                 struct expression fake_expr_stmt = { .smatch_flags = Fake, };
 721
 722                 last_stmt = split_then_return_last(stmt);
 723                 if (!last_stmt) {
 724                         __expr_stmt_count--;
 725                         return 0;
 726                 }
 727
 728                 fake_expr_stmt.pos = last_stmt->pos;
 729                 fake_expr_stmt.type = EXPR_STATEMENT;
 730                 fake_expr_stmt.op = 0;
 731                 fake_expr_stmt.statement = last_stmt;
 732
 733                 fake_assign = assign_expression(expr->left, expr->op, &fake_expr_stmt);
 734                 __split_expr(fake_assign);
 735
 736                 __pass_to_client(stmt, STMT_HOOK_AFTER);
 737                 __call_scope_hooks();
 738         } else if (stmt->type == STMT_EXPRESSION) {
 739                 struct expression *fake_assign;
 740
 741                 fake_assign = assign_expression(expr->left, expr->op, stmt->expression);
 742                 __split_expr(fake_assign);
 743
 744         } else {
 745                 __split_stmt(stmt);
 746         }
 747         __expr_stmt_count--;
 748         return 1;
 749 }
 750
 751 int in_condition(void)
 752 {
 753         return inside_condition;
 754 }