4 * Copyright (C) 2006,2008 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
15 #include "smatch_expression_stacks.h"
16 #include "smatch_extra.h"
17 #include "smatch_slist.h"
21 static int __smatch_lineno
= 0;
23 static const char *filename
;
24 static char *pathname
;
25 static char *full_filename
;
26 static char *cur_func
;
27 static int line_func_start
;
28 static struct expression_list
*switch_expr_stack
= NULL
;
29 struct expression_list
*big_expression_stack
;
30 struct statement_list
*big_statement_stack
;
31 int __in_pre_condition
= 0;
32 int __bail_on_rest_of_function
= 0;
33 char *get_function(void) { return cur_func
; }
34 int get_lineno(void) { return __smatch_lineno
; }
35 int get_func_pos(void) { return __smatch_lineno
- line_func_start
; }
37 static void split_symlist(struct symbol_list
*sym_list
);
38 static void split_declaration(struct symbol_list
*sym_list
);
39 static void split_expr_list(struct expression_list
*expr_list
);
41 int option_assume_loops
= 0;
42 int option_known_conditions
= 0;
43 int option_two_passes
= 0;
44 struct symbol
*cur_func_sym
= NULL
;
46 const char *get_filename(void)
53 static void set_position(struct expression
*expr
)
56 static int prev_stream
= -1;
58 __smatch_lineno
= expr
->pos
.line
;
60 if (expr
->pos
.stream
== prev_stream
)
63 filename
= stream_name(expr
->pos
.stream
);
66 pathname
= getcwd(NULL
, 0);
68 len
= strlen(pathname
) + 1 + strlen(filename
) + 1;
69 full_filename
= malloc(len
);
70 snprintf(full_filename
, len
, "%s/%s", pathname
, filename
);
72 full_filename
= alloc_string(filename
);
77 void __split_expr(struct expression
*expr
)
82 // printf("%d Debug expr_type %d %s\n", get_lineno(), expr->type, show_special(expr->op));
84 push_expression(&big_expression_stack
, expr
);
86 __pass_to_client(expr
, EXPR_HOOK
);
91 __pass_to_client(expr
, DEREF_HOOK
);
93 __pass_to_client(expr
, OP_HOOK
);
94 __split_expr(expr
->unop
);
97 __split_statements(expr
->statement
);
100 __pass_to_client(expr
, BINOP_HOOK
);
104 __split_expr(expr
->left
);
105 __split_expr(expr
->right
);
107 case EXPR_ASSIGNMENT
: {
108 struct expression
*tmp
;
111 if (__handle_condition_assigns(expr
))
114 /* foo = (x < 5 ? foo : 5); */
115 if (__handle_select_assigns(expr
))
118 __split_expr(expr
->right
);
119 __pass_to_client(expr
, ASSIGNMENT_HOOK
);
120 tmp
= strip_expr(expr
->right
);
121 if (tmp
->type
== EXPR_CALL
)
122 __pass_to_client(expr
, CALL_ASSIGNMENT_HOOK
);
123 __split_expr(expr
->left
);
127 __pass_to_client(expr
, DEREF_HOOK
);
128 __split_expr(expr
->deref
);
131 __split_expr(expr
->base
);
134 case EXPR_FORCE_CAST
:
135 __split_expr(expr
->cast_expression
);
138 /* there isn't anything to pass a client from inside a sizeof() */
140 case EXPR_CONDITIONAL
:
142 __split_whole_condition(expr
->conditional
);
143 __split_expr(expr
->cond_true
);
144 __push_true_states();
145 __use_false_states();
146 __split_expr(expr
->cond_false
);
147 __merge_true_states();
150 split_expr_list(expr
->args
);
151 __split_expr(expr
->fn
);
152 __pass_to_client(expr
, FUNCTION_CALL_HOOK
);
154 case EXPR_INITIALIZER
:
155 split_expr_list(expr
->expr_list
);
157 case EXPR_IDENTIFIER
:
158 __split_expr(expr
->ident_expression
);
161 __split_expr(expr
->idx_expression
);
164 __split_expr(expr
->init_expr
);
167 __pass_to_client(expr
, SYM_HOOK
);
172 pop_expression(&big_expression_stack
);
175 static int is_forever_loop(struct statement
*stmt
)
178 struct expression
*expr
;
180 expr
= strip_expr(stmt
->iterator_pre_condition
);
182 expr
= stmt
->iterator_post_condition
;
184 /* this is a for(;;) loop... */
188 if (expr
->type
== EXPR_VALUE
&& expr
->value
== 1) {
196 static char *get_loop_name(int num
)
200 snprintf(buf
, 255, "-loop%d", num
);
202 return alloc_sname(buf
);;
206 * Pre Loops are while and for loops.
209 static void handle_pre_loop(struct statement
*stmt
)
211 int once_through
; /* we go through the loop at least once */
212 struct sm_state
*extra_sm
= NULL
;
215 struct state_list
*slist
= NULL
;
216 struct sm_state
*sm
= NULL
;
218 loop_name
= get_loop_name(loop_num
);
221 __split_statements(stmt
->iterator_pre_statement
);
223 once_through
= implied_condition_true(stmt
->iterator_pre_condition
);
228 __merge_gotos(loop_name
);
230 extra_sm
= __extra_handle_canonical_loops(stmt
, &slist
);
231 __in_pre_condition
++;
232 __split_whole_condition(stmt
->iterator_pre_condition
);
233 __in_pre_condition
--;
234 FOR_EACH_PTR(slist
, sm
) {
235 set_state(sm
->owner
, sm
->name
, sm
->sym
, sm
->state
);
236 } END_FOR_EACH_PTR(sm
);
239 extra_sm
= get_sm_state(extra_sm
->owner
, extra_sm
->name
, extra_sm
->sym
);
241 if (option_assume_loops
)
244 __split_statements(stmt
->iterator_statement
);
245 __warn_on_silly_pre_loops();
246 if (is_forever_loop(stmt
)) {
247 __save_gotos(loop_name
);
248 /* forever loops don't have an iterator_post_statement */
249 __discard_continues();
250 __discard_false_states();
254 unchanged
= __iterator_unchanged(extra_sm
);
255 __split_statements(stmt
->iterator_post_statement
);
256 __save_gotos(loop_name
);
257 __split_whole_condition(stmt
->iterator_pre_condition
);
259 __merge_false_states();
261 __discard_false_states();
263 __merge_false_states();
266 if (extra_sm
&& unchanged
)
267 __extra_pre_loop_hook_after(extra_sm
,
268 stmt
->iterator_post_statement
,
269 stmt
->iterator_pre_condition
);
275 * Post loops are do {} while();
277 static void handle_post_loop(struct statement
*stmt
)
281 loop_name
= get_loop_name(loop_num
);
286 __merge_gotos(loop_name
);
287 __split_statements(stmt
->iterator_statement
);
289 if (!is_zero(stmt
->iterator_post_condition
))
290 __save_gotos(loop_name
);
292 if (is_forever_loop(stmt
)) {
295 __split_whole_condition(stmt
->iterator_post_condition
);
296 __use_false_states();
301 static int empty_statement(struct statement
*stmt
)
305 if (stmt
->type
== STMT_EXPRESSION
&& !stmt
->expression
)
310 static struct statement
*last_stmt
;
311 static int is_last_stmt(struct statement
*stmt
)
313 if (stmt
== last_stmt
)
318 static void print_unreached_initializers(struct symbol_list
*sym_list
)
322 FOR_EACH_PTR(sym_list
, sym
) {
324 sm_msg("info: '%s' is not actually initialized (unreached code).",
325 (sym
->ident
? sym
->ident
->name
: "this variable"));
326 } END_FOR_EACH_PTR(sym
);
329 static void print_unreached(struct statement
*stmt
)
332 static int print
= 1;
334 if (!__path_is_null()) {
341 switch (stmt
->type
) {
342 case STMT_COMPOUND
: /* after a switch before a case stmt */
347 case STMT_DECLARATION
: /* switch (x) { int a; case foo: ... */
348 print_unreached_initializers(stmt
->declaration
);
350 case STMT_RETURN
: /* gcc complains if you don't have a return statement */
351 if (is_last_stmt(stmt
))
361 if (!option_spammy
&& empty_statement(stmt
))
363 sm_msg("info: ignoring unreachable code.");
367 void __split_statements(struct statement
*stmt
)
372 if (out_of_memory() || __bail_on_rest_of_function
) {
373 static char *printed
= NULL
;
375 if (printed
!= cur_func
)
376 sm_msg("Function too hairy. Giving up.");
381 add_ptr_list(&big_statement_stack
, stmt
);
382 free_expression_stack(&big_expression_stack
);
383 __smatch_lineno
= stmt
->pos
.line
;
384 print_unreached(stmt
);
385 __pass_to_client(stmt
, STMT_HOOK
);
387 switch (stmt
->type
) {
388 case STMT_DECLARATION
:
389 split_declaration(stmt
->declaration
);
392 __split_expr(stmt
->ret_value
);
393 __pass_to_client(stmt
->ret_value
, RETURN_HOOK
);
396 case STMT_EXPRESSION
:
397 __split_expr(stmt
->expression
);
399 case STMT_COMPOUND
: {
403 last_stmt
= last_ptr_list((struct ptr_list
*)stmt
->stmts
);
404 __push_scope_hooks();
405 FOR_EACH_PTR(stmt
->stmts
, s
) {
406 __split_statements(s
);
407 } END_FOR_EACH_PTR(s
);
408 __call_scope_hooks();
412 if (known_condition_true(stmt
->if_conditional
)) {
413 __split_statements(stmt
->if_true
);
416 if (known_condition_false(stmt
->if_conditional
)) {
417 __split_statements(stmt
->if_false
);
420 if (option_known_conditions
&&
421 implied_condition_true(stmt
->if_conditional
)) {
422 sm_info("this condition is true.");
423 __split_statements(stmt
->if_true
);
426 if (option_known_conditions
&&
427 implied_condition_false(stmt
->if_conditional
)) {
428 sm_info("this condition is false.");
429 __split_statements(stmt
->if_false
);
432 __split_whole_condition(stmt
->if_conditional
);
433 __split_statements(stmt
->if_true
);
434 if (empty_statement(stmt
->if_true
))
435 sm_msg("warn: if();");
436 __push_true_states();
437 __use_false_states();
438 __split_statements(stmt
->if_false
);
439 __merge_true_states();
442 if (stmt
->iterator_pre_condition
)
443 handle_pre_loop(stmt
);
444 else if (stmt
->iterator_post_condition
)
445 handle_post_loop(stmt
);
447 // these are for(;;) type loops.
448 handle_pre_loop(stmt
);
452 __split_expr(stmt
->switch_expression
);
453 push_expression(&switch_expr_stack
, stmt
->switch_expression
);
454 __save_switch_states(top_expression(switch_expr_stack
));
458 __split_statements(stmt
->switch_statement
);
459 if (!__pop_default())
460 __merge_switches(top_expression(switch_expr_stack
),
462 __discard_switches();
464 pop_expression(&switch_expr_stack
);
467 __merge_switches(top_expression(switch_expr_stack
),
468 stmt
->case_expression
);
469 __pass_case_to_client(top_expression(switch_expr_stack
),
470 stmt
->case_expression
);
471 if (!stmt
->case_expression
)
473 __split_expr(stmt
->case_expression
);
474 __split_expr(stmt
->case_to
);
475 __split_statements(stmt
->case_statement
);
479 stmt
->label
->type
== SYM_LABEL
&&
480 stmt
->label
->ident
) {
481 __merge_gotos(stmt
->label
->ident
->name
);
483 __split_statements(stmt
->label_statement
);
486 __split_expr(stmt
->goto_expression
);
487 if (stmt
->goto_label
&& stmt
->goto_label
->type
== SYM_NODE
) {
488 if (!strcmp(stmt
->goto_label
->ident
->name
, "break")) {
490 } else if (!strcmp(stmt
->goto_label
->ident
->name
,
492 __process_continues();
494 } else if (stmt
->goto_label
&&
495 stmt
->goto_label
->type
== SYM_LABEL
&&
496 stmt
->goto_label
->ident
) {
497 __save_gotos(stmt
->goto_label
->ident
->name
);
504 __split_expr(stmt
->asm_string
);
505 split_expr_list(stmt
->asm_outputs
);
506 split_expr_list(stmt
->asm_inputs
);
507 split_expr_list(stmt
->asm_clobbers
);
512 __split_expr(stmt
->range_expression
);
513 __split_expr(stmt
->range_low
);
514 __split_expr(stmt
->range_high
);
519 static void split_expr_list(struct expression_list
*expr_list
)
521 struct expression
*expr
;
522 FOR_EACH_PTR(expr_list
, expr
) {
524 } END_FOR_EACH_PTR(expr
);
528 static void split_sym(struct symbol
*sym
)
532 if (!(sym
->namespace & NS_SYMBOL
))
535 __split_statements(sym
->stmt
);
536 __split_expr(sym
->array_size
);
537 split_symlist(sym
->arguments
);
538 split_symlist(sym
->symbol_list
);
539 __split_statements(sym
->inline_stmt
);
540 split_symlist(sym
->inline_symbol_list
);
543 static void split_symlist(struct symbol_list
*sym_list
)
547 FOR_EACH_PTR(sym_list
, sym
) {
549 } END_FOR_EACH_PTR(sym
);
552 static struct expression
*fake_assign_expr(struct symbol
*sym
)
554 struct expression
*e_assign
, *e_symbol
;
556 e_assign
= alloc_expression(sym
->initializer
->pos
, EXPR_ASSIGNMENT
);
557 e_symbol
= alloc_expression(sym
->initializer
->pos
, EXPR_SYMBOL
);
558 e_assign
->op
= (int)'=';
559 e_symbol
->symbol
= sym
;
560 e_symbol
->symbol_name
= sym
->ident
;
561 e_assign
->left
= e_symbol
;
562 e_assign
->right
= sym
->initializer
;
566 static void do_initializer_stuff(struct symbol
*sym
)
568 struct expression
*assign
;
570 if(!sym
->initializer
)
572 assign
= fake_assign_expr(sym
);
573 __split_expr(assign
);
576 static void split_declaration(struct symbol_list
*sym_list
)
580 FOR_EACH_PTR(sym_list
, sym
) {
581 __pass_to_client(sym
, DECLARATION_HOOK
);
582 do_initializer_stuff(sym
);
584 } END_FOR_EACH_PTR(sym
);
587 static void split_functions(struct symbol_list
*sym_list
)
591 FOR_EACH_PTR(sym_list
, sym
) {
592 struct symbol
*base_type
;
593 base_type
= get_base_type(sym
);
594 if (sym
->type
== SYM_NODE
&& base_type
->type
== SYM_FN
) {
597 line_func_start
= base_type
->stmt
->pos
.line
;
599 cur_func
= sym
->ident
->name
;
600 __smatch_lineno
= sym
->pos
.line
;
602 sm_debug("new function: %s\n", cur_func
);
603 if (option_two_passes
) {
607 __pass_to_client(sym
, FUNC_DEF_HOOK
);
608 __split_statements(base_type
->stmt
);
614 __pass_to_client(sym
, FUNC_DEF_HOOK
);
615 __split_statements(base_type
->stmt
);
616 __pass_to_client(sym
, END_FUNC_HOOK
);
620 free_data_info_allocs();
621 free_expression_stack(&switch_expr_stack
);
622 __free_ptr_list((struct ptr_list
**)&big_statement_stack
);
623 __bail_on_rest_of_function
= 0;
625 __pass_to_client(sym
, BASE_HOOK
);
627 } END_FOR_EACH_PTR(sym
);
628 __pass_to_client_no_data(END_FILE_HOOK
);
631 void smatch (int argc
, char **argv
)
634 struct string_list
*filelist
= NULL
;
635 struct symbol_list
*sym_list
;
639 printf("Usage: smatch [--debug] <filename.c>\n");
642 sparse_initialize(argc
, argv
, &filelist
);
643 FOR_EACH_PTR_NOTAG(filelist
, file
) {
644 sym_list
= __sparse(file
);
645 split_functions(sym_list
);
646 } END_FOR_EACH_PTR_NOTAG(file
);