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 int loop_count
;
29 int __expr_stmt_count
;
30 static struct expression_list
*switch_expr_stack
= NULL
;
32 struct expression_list
*big_expression_stack
;
33 struct statement_list
*big_statement_stack
;
34 int __in_pre_condition
= 0;
35 int __bail_on_rest_of_function
= 0;
36 char *get_function(void) { return cur_func
; }
37 int get_lineno(void) { return __smatch_lineno
; }
38 int inside_loop(void) { return !!loop_count
; }
39 int in_expression_statement(void) { return !!__expr_stmt_count
; }
41 static void split_symlist(struct symbol_list
*sym_list
);
42 static void split_declaration(struct symbol_list
*sym_list
);
43 static void split_expr_list(struct expression_list
*expr_list
);
44 static void add_inline_function(struct symbol
*sym
);
46 int option_assume_loops
= 0;
47 int option_known_conditions
= 0;
48 int option_two_passes
= 0;
49 struct symbol
*cur_func_sym
= NULL
;
51 const char *get_filename(void)
58 static void set_position(struct position pos
)
61 static int prev_stream
= -1;
63 __smatch_lineno
= pos
.line
;
65 if (pos
.stream
== prev_stream
)
68 filename
= stream_name(pos
.stream
);
71 pathname
= getcwd(NULL
, 0);
73 len
= strlen(pathname
) + 1 + strlen(filename
) + 1;
74 full_filename
= malloc(len
);
75 snprintf(full_filename
, len
, "%s/%s", pathname
, filename
);
77 full_filename
= alloc_string(filename
);
82 static int is_inline_func(struct expression
*expr
)
84 if (expr
->type
!= EXPR_SYMBOL
|| !expr
->symbol
)
86 if (expr
->symbol
->ctype
.modifiers
& MOD_INLINE
)
91 void __split_expr(struct expression
*expr
)
96 // sm_msg(" Debug expr_type %d %s", expr->type, show_special(expr->op));
98 push_expression(&big_expression_stack
, expr
);
99 set_position(expr
->pos
);
100 __pass_to_client(expr
, EXPR_HOOK
);
102 switch (expr
->type
) {
105 __pass_to_client(expr
, DEREF_HOOK
);
107 __pass_to_client(expr
, OP_HOOK
);
108 __split_expr(expr
->unop
);
112 __split_stmt(expr
->statement
);
117 __pass_to_client(expr
, LOGIC_HOOK
);
118 __handle_logic(expr
);
121 __pass_to_client(expr
, BINOP_HOOK
);
123 __split_expr(expr
->left
);
124 __split_expr(expr
->right
);
126 case EXPR_ASSIGNMENT
: {
127 struct expression
*tmp
;
132 __pass_to_client(expr
, RAW_ASSIGNMENT_HOOK
);
135 if (__handle_condition_assigns(expr
))
137 /* foo = (x < 5 ? foo : 5); */
138 if (__handle_select_assigns(expr
))
140 /* foo = ({frob(); frob(); frob(); 1;}) */
141 if (__handle_expr_statement_assigns(expr
))
144 __split_expr(expr
->right
);
145 __pass_to_client(expr
, ASSIGNMENT_HOOK
);
146 tmp
= strip_expr(expr
->right
);
147 if (tmp
->type
== EXPR_CALL
)
148 __pass_to_client(expr
, CALL_ASSIGNMENT_HOOK
);
149 if (get_macro_name(tmp
->pos
))
150 __pass_to_client(expr
, MACRO_ASSIGNMENT_HOOK
);
151 __split_expr(expr
->left
);
155 __pass_to_client(expr
, DEREF_HOOK
);
156 __split_expr(expr
->deref
);
159 __split_expr(expr
->base
);
162 case EXPR_FORCE_CAST
:
163 __pass_to_client(expr
, CAST_HOOK
);
164 __split_expr(expr
->cast_expression
);
167 /* there isn't anything to pass a client from inside a sizeof() */
169 case EXPR_CONDITIONAL
:
171 if (known_condition_true(expr
->conditional
)) {
172 __split_expr(expr
->cond_true
);
175 if (known_condition_false(expr
->conditional
)) {
176 __split_expr(expr
->cond_false
);
179 __pass_to_client(expr
, SELECT_HOOK
);
180 __split_whole_condition(expr
->conditional
);
181 __split_expr(expr
->cond_true
);
182 __push_true_states();
183 __use_false_states();
184 __split_expr(expr
->cond_false
);
185 __merge_true_states();
188 if (sym_name_is("__builtin_constant_p", expr
->fn
))
190 split_expr_list(expr
->args
);
191 __split_expr(expr
->fn
);
192 if (is_inline_func(expr
->fn
))
193 add_inline_function(expr
->fn
->symbol
);
194 __pass_to_client(expr
, FUNCTION_CALL_HOOK
);
196 case EXPR_INITIALIZER
:
197 split_expr_list(expr
->expr_list
);
199 case EXPR_IDENTIFIER
:
200 __split_expr(expr
->ident_expression
);
203 __split_expr(expr
->idx_expression
);
206 __split_expr(expr
->init_expr
);
209 __pass_to_client(expr
, SYM_HOOK
);
212 __pass_to_client(expr
, STRING_HOOK
);
217 pop_expression(&big_expression_stack
);
220 static int is_forever_loop(struct statement
*stmt
)
222 struct expression
*expr
;
224 expr
= strip_expr(stmt
->iterator_pre_condition
);
226 expr
= stmt
->iterator_post_condition
;
228 /* this is a for(;;) loop... */
232 if (expr
->type
== EXPR_VALUE
&& expr
->value
== 1)
239 static char *get_loop_name(int num
)
243 snprintf(buf
, 255, "-loop%d", num
);
245 return alloc_sname(buf
);
249 * Pre Loops are while and for loops.
251 static void handle_pre_loop(struct statement
*stmt
)
253 int once_through
; /* we go through the loop at least once */
254 struct sm_state
*extra_sm
= NULL
;
257 struct state_list
*slist
= NULL
;
258 struct sm_state
*sm
= NULL
;
260 loop_name
= get_loop_name(loop_num
);
263 __split_stmt(stmt
->iterator_pre_statement
);
265 once_through
= implied_condition_true(stmt
->iterator_pre_condition
);
271 __merge_gotos(loop_name
);
273 extra_sm
= __extra_handle_canonical_loops(stmt
, &slist
);
274 __in_pre_condition
++;
275 __pass_to_client(stmt
, PRELOOP_HOOK
);
276 __split_whole_condition(stmt
->iterator_pre_condition
);
277 __in_pre_condition
--;
278 FOR_EACH_PTR(slist
, sm
) {
279 set_state(sm
->owner
, sm
->name
, sm
->sym
, sm
->state
);
280 } END_FOR_EACH_PTR(sm
);
283 extra_sm
= get_sm_state(extra_sm
->owner
, extra_sm
->name
, extra_sm
->sym
);
285 if (option_assume_loops
)
288 __split_stmt(stmt
->iterator_statement
);
289 __warn_on_silly_pre_loops();
290 if (is_forever_loop(stmt
)) {
291 struct state_list
*slist
;
293 __save_gotos(loop_name
);
295 __push_fake_cur_slist();
296 __split_stmt(stmt
->iterator_post_statement
);
297 slist
= __pop_fake_cur_slist();
299 __discard_continues();
300 __discard_false_states();
303 if (!__path_is_null())
304 __merge_slist_into_cur(slist
);
308 unchanged
= __iterator_unchanged(extra_sm
);
309 __split_stmt(stmt
->iterator_post_statement
);
310 __save_gotos(loop_name
);
311 __split_whole_condition(stmt
->iterator_pre_condition
);
313 __merge_false_states();
315 __discard_false_states();
317 __merge_false_states();
319 if (extra_sm
&& unchanged
)
320 __extra_pre_loop_hook_after(extra_sm
,
321 stmt
->iterator_post_statement
,
322 stmt
->iterator_pre_condition
);
329 * Post loops are do {} while();
331 static void handle_post_loop(struct statement
*stmt
)
335 loop_name
= get_loop_name(loop_num
);
341 __merge_gotos(loop_name
);
342 __split_stmt(stmt
->iterator_statement
);
344 if (!is_zero(stmt
->iterator_post_condition
))
345 __save_gotos(loop_name
);
347 if (is_forever_loop(stmt
)) {
350 __split_whole_condition(stmt
->iterator_post_condition
);
351 __use_false_states();
357 static int empty_statement(struct statement
*stmt
)
361 if (stmt
->type
== STMT_EXPRESSION
&& !stmt
->expression
)
366 static int last_stmt_on_same_line()
368 struct statement
*stmt
;
371 FOR_EACH_PTR_REVERSE(big_statement_stack
, stmt
) {
374 if (stmt
->pos
.line
== get_lineno())
377 } END_FOR_EACH_PTR_REVERSE(stmt
);
381 static struct statement
*last_stmt
;
382 static int is_last_stmt(struct statement
*stmt
)
384 if (stmt
== last_stmt
)
389 static void print_unreached_initializers(struct symbol_list
*sym_list
)
393 FOR_EACH_PTR(sym_list
, sym
) {
394 if (sym
->initializer
)
395 sm_msg("info: '%s' is not actually initialized (unreached code).",
396 (sym
->ident
? sym
->ident
->name
: "this variable"));
397 } END_FOR_EACH_PTR(sym
);
400 static void print_unreached(struct statement
*stmt
)
402 static int print
= 1;
404 if (!__path_is_null()) {
411 switch (stmt
->type
) {
412 case STMT_COMPOUND
: /* after a switch before a case stmt */
417 case STMT_DECLARATION
: /* switch (x) { int a; case foo: ... */
418 print_unreached_initializers(stmt
->declaration
);
420 case STMT_RETURN
: /* gcc complains if you don't have a return statement */
421 if (is_last_stmt(stmt
))
431 if (!option_spammy
&& empty_statement(stmt
))
433 sm_msg("info: ignoring unreachable code.");
437 static void split_asm_constraints(struct expression_list
*expr_list
)
439 struct expression
*expr
;
442 FOR_EACH_PTR(expr_list
, expr
) {
444 case 0: /* identifier */
445 case 1: /* constraint */
448 case 2: /* expression */
453 } END_FOR_EACH_PTR(expr
);
456 static int is_case_val(struct statement
*stmt
, long long val
)
460 if (stmt
->type
!= STMT_CASE
)
462 if (!stmt
->case_expression
) {
466 if (!get_value(stmt
->case_expression
, &case_val
))
473 static void split_known_switch(struct statement
*stmt
, long long val
)
475 struct statement
*tmp
;
477 __split_expr(stmt
->switch_expression
);
479 push_expression(&switch_expr_stack
, stmt
->switch_expression
);
480 __save_switch_states(top_expression(switch_expr_stack
));
485 stmt
= stmt
->switch_statement
;
488 last_stmt
= last_ptr_list((struct ptr_list
*)stmt
->stmts
);
490 __push_scope_hooks();
491 FOR_EACH_PTR(stmt
->stmts
, tmp
) {
492 __smatch_lineno
= tmp
->pos
.line
;
493 if (is_case_val(tmp
, val
)) {
494 __merge_switches(top_expression(switch_expr_stack
),
495 stmt
->case_expression
);
496 __pass_case_to_client(top_expression(switch_expr_stack
),
497 stmt
->case_expression
);
499 if (__path_is_null())
502 if (__path_is_null()) {
506 } END_FOR_EACH_PTR(tmp
);
508 __call_scope_hooks();
509 if (!__pop_default())
510 __merge_switches(top_expression(switch_expr_stack
),
512 __discard_switches();
514 pop_expression(&switch_expr_stack
);
517 void __split_stmt(struct statement
*stmt
)
524 if (out_of_memory() || __bail_on_rest_of_function
) {
525 static char *printed
= NULL
;
527 if (printed
!= cur_func
)
528 sm_msg("Function too hairy. Giving up.");
533 add_ptr_list(&big_statement_stack
, stmt
);
534 free_expression_stack(&big_expression_stack
);
535 set_position(stmt
->pos
);
536 print_unreached(stmt
);
537 __pass_to_client(stmt
, STMT_HOOK
);
539 switch (stmt
->type
) {
540 case STMT_DECLARATION
:
541 split_declaration(stmt
->declaration
);
544 __split_expr(stmt
->ret_value
);
545 __pass_to_client(stmt
->ret_value
, RETURN_HOOK
);
548 case STMT_EXPRESSION
:
549 __split_expr(stmt
->expression
);
551 case STMT_COMPOUND
: {
552 struct statement
*tmp
;
555 last_stmt
= last_ptr_list((struct ptr_list
*)stmt
->stmts
);
556 __push_scope_hooks();
557 FOR_EACH_PTR(stmt
->stmts
, tmp
) {
559 } END_FOR_EACH_PTR(tmp
);
560 __call_scope_hooks();
564 if (known_condition_true(stmt
->if_conditional
)) {
565 __split_stmt(stmt
->if_true
);
568 if (known_condition_false(stmt
->if_conditional
)) {
569 __split_stmt(stmt
->if_false
);
572 if (option_known_conditions
&&
573 implied_condition_true(stmt
->if_conditional
)) {
574 sm_info("this condition is true.");
575 __split_stmt(stmt
->if_true
);
578 if (option_known_conditions
&&
579 implied_condition_false(stmt
->if_conditional
)) {
580 sm_info("this condition is false.");
581 __split_stmt(stmt
->if_false
);
584 __split_whole_condition(stmt
->if_conditional
);
585 __split_stmt(stmt
->if_true
);
586 if (empty_statement(stmt
->if_true
) &&
587 last_stmt_on_same_line() &&
588 !get_macro_name(stmt
->if_true
->pos
))
589 sm_msg("warn: if();");
590 __push_true_states();
591 __use_false_states();
592 __split_stmt(stmt
->if_false
);
593 __merge_true_states();
596 if (stmt
->iterator_pre_condition
)
597 handle_pre_loop(stmt
);
598 else if (stmt
->iterator_post_condition
)
599 handle_post_loop(stmt
);
601 // these are for(;;) type loops.
602 handle_pre_loop(stmt
);
606 if (get_value(stmt
->switch_expression
, &val
)) {
607 split_known_switch(stmt
, val
);
610 __split_expr(stmt
->switch_expression
);
611 push_expression(&switch_expr_stack
, stmt
->switch_expression
);
612 __save_switch_states(top_expression(switch_expr_stack
));
616 __split_stmt(stmt
->switch_statement
);
617 if (!__pop_default())
618 __merge_switches(top_expression(switch_expr_stack
),
620 __discard_switches();
622 pop_expression(&switch_expr_stack
);
625 __merge_switches(top_expression(switch_expr_stack
),
626 stmt
->case_expression
);
627 __pass_case_to_client(top_expression(switch_expr_stack
),
628 stmt
->case_expression
);
629 if (!stmt
->case_expression
)
631 __split_expr(stmt
->case_expression
);
632 __split_expr(stmt
->case_to
);
633 __split_stmt(stmt
->case_statement
);
636 if (stmt
->label_identifier
&&
637 stmt
->label_identifier
->type
== SYM_LABEL
&&
638 stmt
->label_identifier
->ident
) {
639 loop_count
= 1000000;
640 __merge_gotos(stmt
->label_identifier
->ident
->name
);
642 __split_stmt(stmt
->label_statement
);
645 __split_expr(stmt
->goto_expression
);
646 if (stmt
->goto_label
&& stmt
->goto_label
->type
== SYM_NODE
) {
647 if (!strcmp(stmt
->goto_label
->ident
->name
, "break")) {
649 } else if (!strcmp(stmt
->goto_label
->ident
->name
,
651 __process_continues();
653 } else if (stmt
->goto_label
&&
654 stmt
->goto_label
->type
== SYM_LABEL
&&
655 stmt
->goto_label
->ident
) {
656 __save_gotos(stmt
->goto_label
->ident
->name
);
663 __pass_to_client(stmt
, ASM_HOOK
);
664 __split_expr(stmt
->asm_string
);
665 split_asm_constraints(stmt
->asm_outputs
);
666 split_asm_constraints(stmt
->asm_inputs
);
667 split_asm_constraints(stmt
->asm_clobbers
);
672 __split_expr(stmt
->range_expression
);
673 __split_expr(stmt
->range_low
);
674 __split_expr(stmt
->range_high
);
679 static void split_expr_list(struct expression_list
*expr_list
)
681 struct expression
*expr
;
683 FOR_EACH_PTR(expr_list
, expr
) {
685 } END_FOR_EACH_PTR(expr
);
688 static void split_sym(struct symbol
*sym
)
692 if (!(sym
->namespace & NS_SYMBOL
))
695 __split_stmt(sym
->stmt
);
696 __split_expr(sym
->array_size
);
697 split_symlist(sym
->arguments
);
698 split_symlist(sym
->symbol_list
);
699 __split_stmt(sym
->inline_stmt
);
700 split_symlist(sym
->inline_symbol_list
);
703 static void split_symlist(struct symbol_list
*sym_list
)
707 FOR_EACH_PTR(sym_list
, sym
) {
709 } END_FOR_EACH_PTR(sym
);
712 static struct expression
*fake_assign_expr(struct symbol
*sym
)
714 struct expression
*e_assign
, *e_symbol
;
716 e_assign
= alloc_expression(sym
->initializer
->pos
, EXPR_ASSIGNMENT
);
717 e_symbol
= alloc_expression(sym
->pos
, EXPR_SYMBOL
);
718 e_assign
->op
= (int)'=';
719 e_symbol
->symbol
= sym
;
720 e_symbol
->symbol_name
= sym
->ident
;
721 e_assign
->left
= e_symbol
;
722 e_assign
->right
= sym
->initializer
;
726 static void do_initializer_stuff(struct symbol
*sym
)
728 struct expression
*assign
;
730 if (!sym
->initializer
)
732 assign
= fake_assign_expr(sym
);
733 __split_expr(assign
);
736 static void split_declaration(struct symbol_list
*sym_list
)
740 FOR_EACH_PTR(sym_list
, sym
) {
741 __pass_to_client(sym
, DECLARATION_HOOK
);
742 do_initializer_stuff(sym
);
744 } END_FOR_EACH_PTR(sym
);
747 static void split_function(struct symbol
*sym
)
749 struct symbol
*base_type
= get_base_type(sym
);
753 line_func_start
= base_type
->stmt
->pos
.line
;
755 cur_func
= sym
->ident
->name
;
756 __smatch_lineno
= sym
->pos
.line
;
759 sm_debug("new function: %s\n", cur_func
);
760 if (option_two_passes
) {
764 __pass_to_client(sym
, FUNC_DEF_HOOK
);
765 __split_stmt(base_type
->stmt
);
766 __split_stmt(base_type
->inline_stmt
);
772 __pass_to_client(sym
, FUNC_DEF_HOOK
);
773 __split_stmt(base_type
->stmt
);
774 __split_stmt(base_type
->inline_stmt
);
775 __pass_to_client(sym
, END_FUNC_HOOK
);
779 free_data_info_allocs();
780 free_expression_stack(&switch_expr_stack
);
781 __free_ptr_list((struct ptr_list
**)&big_statement_stack
);
782 __bail_on_rest_of_function
= 0;
785 static struct symbol_list
*inlines_called
;
786 static void add_inline_function(struct symbol
*sym
)
788 static struct symbol_list
*already_added
;
791 FOR_EACH_PTR(already_added
, tmp
) {
794 } END_FOR_EACH_PTR(tmp
);
796 add_ptr_list(&already_added
, sym
);
797 add_ptr_list(&inlines_called
, sym
);
800 static void process_inlines()
804 FOR_EACH_PTR(inlines_called
, tmp
) {
806 } END_FOR_EACH_PTR(tmp
);
807 free_ptr_list(&inlines_called
);
810 static void split_functions(struct symbol_list
*sym_list
)
814 FOR_EACH_PTR(sym_list
, sym
) {
815 set_position(sym
->pos
);
816 if (sym
->type
== SYM_NODE
&& get_base_type(sym
)->type
== SYM_FN
) {
820 __pass_to_client(sym
, BASE_HOOK
);
822 } END_FOR_EACH_PTR(sym
);
823 __pass_to_client_no_data(END_FILE_HOOK
);
826 void smatch(int argc
, char **argv
)
829 struct string_list
*filelist
= NULL
;
830 struct symbol_list
*sym_list
;
834 printf("Usage: smatch [--debug] <filename.c>\n");
837 sparse_initialize(argc
, argv
, &filelist
);
838 FOR_EACH_PTR_NOTAG(filelist
, file
) {
839 if (option_file_output
) {
842 snprintf(buf
, sizeof(buf
), "%s.smatch", file
);
843 sm_outfd
= fopen(buf
, "w");
845 printf("Error: Cannot open %s\n", file
);
849 sym_list
= sparse_keep_tokens(file
);
850 split_functions(sym_list
);
851 } END_FOR_EACH_PTR_NOTAG(file
);