4 * Copyright (C) 2006,2008 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
13 #include "smatch_expression_stacks.h"
14 #include "smatch_extra.h"
15 #include "smatch_slist.h" // just for sname.
19 static int __smatch_lineno
= 0;
21 static char *filename
;
22 static char *cur_func
;
23 static int line_func_start
;
24 static struct expression_stack
*switch_expr_stack
= NULL
;
26 char *get_filename(void) { return filename
; }
27 char *get_function(void) { return cur_func
; }
28 int get_lineno(void) { return __smatch_lineno
; }
29 int get_func_pos(void) { return __smatch_lineno
- line_func_start
; }
31 static void split_symlist(struct symbol_list
*sym_list
);
32 static void split_declaration(struct symbol_list
*sym_list
);
33 static void split_expr_list(struct expression_list
*expr_list
);
35 int option_assume_loops
= 0;
36 int option_known_conditions
= 0;
37 int option_two_passes
= 0;
38 struct symbol
*cur_func_sym
= NULL
;
40 void __split_expr(struct expression
*expr
)
45 // printf("%d Debug expr_type %d %s\n", get_lineno(), expr->type, show_special(expr->op));
47 __smatch_lineno
= expr
->pos
.line
;
48 __pass_to_client(expr
, EXPR_HOOK
);
53 __pass_to_client(expr
, DEREF_HOOK
);
55 __pass_to_client(expr
, OP_HOOK
);
56 __split_expr(expr
->unop
);
59 __split_statements(expr
->statement
);
62 __split_whole_condition(expr
);
65 __merge_true_states();
66 __pop_false_only_stack();
73 __split_expr(expr
->left
);
74 __split_expr(expr
->right
);
76 case EXPR_ASSIGNMENT
: {
77 struct expression
*tmp
;
79 __split_expr(expr
->right
);
80 __pass_to_client(expr
, ASSIGNMENT_HOOK
);
81 tmp
= strip_expr(expr
->right
);
82 if (tmp
->type
== EXPR_CALL
)
83 __pass_to_client(expr
, CALL_ASSIGNMENT_HOOK
);
84 __split_expr(expr
->left
);
88 __pass_to_client(expr
, DEREF_HOOK
);
89 __split_expr(expr
->deref
);
92 __split_expr(expr
->base
);
95 __split_expr(expr
->cast_expression
);
98 /* there isn't anything to pass a client from inside a sizeof() */
100 case EXPR_CONDITIONAL
:
102 __split_whole_condition(expr
->conditional
);
103 __split_expr(expr
->cond_true
);
104 __push_true_states();
105 __use_false_states();
106 __split_expr(expr
->cond_false
);
107 __merge_true_states();
108 __pop_false_only_stack();
111 split_expr_list(expr
->args
);
112 __split_expr(expr
->fn
);
113 __pass_to_client(expr
, FUNCTION_CALL_HOOK
);
115 case EXPR_INITIALIZER
:
116 split_expr_list(expr
->expr_list
);
118 case EXPR_IDENTIFIER
:
119 __split_expr(expr
->ident_expression
);
122 __split_expr(expr
->idx_expression
);
125 __split_expr(expr
->init_expr
);
132 static int is_forever_loop(struct statement
*stmt
)
135 struct expression
*expr
;
137 expr
= strip_expr(stmt
->iterator_pre_condition
);
139 expr
= stmt
->iterator_post_condition
;
141 /* this is a for(;;) loop... */
145 if (expr
->type
== EXPR_VALUE
&& expr
->value
== 1) {
153 static char *get_loop_name(int num
)
157 snprintf(buf
, 255, "-loop%d", num
);
159 return alloc_sname(buf
);;
163 * Pre Loops are while and for loops.
166 static void handle_pre_loop(struct statement
*stmt
)
168 int once_through
; /* we go through the loop at least once */
169 struct sm_state
*extra_state
= NULL
;
173 loop_name
= get_loop_name(loop_num
);
176 __split_statements(stmt
->iterator_pre_statement
);
178 once_through
= implied_condition_true(stmt
->iterator_pre_condition
);
183 __merge_gotos(loop_name
);
184 __split_whole_condition(stmt
->iterator_pre_condition
);
186 extra_state
= __extra_pre_loop_hook_before(stmt
->iterator_pre_statement
);
187 if (option_assume_loops
)
189 __split_statements(stmt
->iterator_statement
);
191 __warn_on_silly_pre_loops();
192 if (is_forever_loop(stmt
)) {
193 __save_gotos(loop_name
);
194 __pop_false_only_stack();
195 /* forever loops don't have an iterator_post_statement */
197 __pop_false_states();
199 } else if (once_through
) {
202 unchanged
= __iterator_unchanged(extra_state
, stmt
->iterator_post_statement
);
203 __split_statements(stmt
->iterator_post_statement
);
204 __save_gotos(loop_name
);
205 __split_whole_condition(stmt
->iterator_pre_condition
);
207 __merge_false_states();
208 if (extra_state
&& unchanged
)
209 __extra_pre_loop_hook_after(extra_state
,
210 stmt
->iterator_post_statement
, stmt
->iterator_pre_condition
);
211 __pop_false_states();
212 __pop_false_only_stack();
213 __pop_false_only_stack();
217 __split_statements(stmt
->iterator_post_statement
);
218 __save_gotos(loop_name
);
219 __merge_false_states();
220 __use_false_only_stack();
226 * Post loops are do {} while();
228 static void handle_post_loop(struct statement
*stmt
)
232 loop_name
= get_loop_name(loop_num
);
237 __merge_gotos(loop_name
);
238 __split_statements(stmt
->iterator_statement
);
240 if (!is_zero(stmt
->iterator_post_condition
))
241 __save_gotos(loop_name
);
243 if (is_forever_loop(stmt
)) {
246 __split_whole_condition(stmt
->iterator_post_condition
);
247 __use_false_states();
250 __pop_false_only_stack();
253 static void print_unreached(struct statement
*stmt
)
257 * GCC insists on a return statement even where it is never
258 * reached. Also BUG() sometimes is a forever loop and
259 * sometimes not so people put code after a BUG(). There
260 * are way to many false positives.
264 if (__path_is_null()) {
266 case STMT_COMPOUND
: /* after a switch before a case stmt */
269 case STMT_DECLARATION
: /* switch(x) { int a; case foo: ... */
272 sm_msg("unreachable code. %d", stmt
->type
);
277 void __split_statements(struct statement
*stmt
)
282 if (out_of_memory()) {
283 static char *printed
= NULL
;
285 if (printed
!= cur_func
)
286 sm_msg("Function too big. Giving up.");
291 __smatch_lineno
= stmt
->pos
.line
;
292 print_unreached(stmt
);
293 __pass_to_client(stmt
, STMT_HOOK
);
295 switch (stmt
->type
) {
296 case STMT_DECLARATION
:
297 split_declaration(stmt
->declaration
);
300 __split_expr(stmt
->ret_value
);
301 __pass_to_client(stmt
->ret_value
, RETURN_HOOK
);
304 case STMT_EXPRESSION
:
305 __split_expr(stmt
->expression
);
307 case STMT_COMPOUND
: {
309 __push_scope_hooks();
310 FOR_EACH_PTR(stmt
->stmts
, s
) {
311 __split_statements(s
);
312 } END_FOR_EACH_PTR(s
);
313 __call_scope_hooks();
317 if (known_condition_true(stmt
->if_conditional
)) {
318 __split_statements(stmt
->if_true
);
321 if (known_condition_false(stmt
->if_conditional
)) {
322 __split_statements(stmt
->if_false
);
325 if (option_known_conditions
&&
326 implied_condition_true(stmt
->if_conditional
)) {
327 sm_msg("info: this condition is true.");
328 __split_statements(stmt
->if_true
);
331 if (option_known_conditions
&&
332 implied_condition_false(stmt
->if_conditional
)) {
333 sm_msg("info: this condition is false.");
334 __split_statements(stmt
->if_false
);
337 __split_whole_condition(stmt
->if_conditional
);
338 __split_statements(stmt
->if_true
);
339 __push_true_states();
340 __use_false_states();
341 __split_statements(stmt
->if_false
);
342 __merge_true_states();
343 __pop_false_only_stack();
346 if (stmt
->iterator_pre_condition
)
347 handle_pre_loop(stmt
);
348 else if (stmt
->iterator_post_condition
)
349 handle_post_loop(stmt
);
351 // these are for(;;) type loops.
352 handle_pre_loop(stmt
);
356 __split_expr(stmt
->switch_expression
);
357 push_expression(&switch_expr_stack
, stmt
->switch_expression
);
358 __save_switch_states(top_expression(switch_expr_stack
));
362 __split_statements(stmt
->switch_statement
);
363 if (!__pop_default())
364 __merge_switches(top_expression(switch_expr_stack
),
368 pop_expression(&switch_expr_stack
);
371 __merge_switches(top_expression(switch_expr_stack
),
372 stmt
->case_expression
);
373 __pass_case_to_client(top_expression(switch_expr_stack
),
374 stmt
->case_expression
);
375 if (!stmt
->case_expression
)
377 __split_expr(stmt
->case_expression
);
378 __split_expr(stmt
->case_to
);
379 __split_statements(stmt
->case_statement
);
383 stmt
->label
->type
== SYM_LABEL
&&
384 stmt
->label
->ident
) {
385 __merge_gotos(stmt
->label
->ident
->name
);
387 __split_statements(stmt
->label_statement
);
390 __split_expr(stmt
->goto_expression
);
391 if (stmt
->goto_label
&& stmt
->goto_label
->type
== SYM_NODE
) {
392 if (!strcmp(stmt
->goto_label
->ident
->name
, "break")) {
394 } else if (!strcmp(stmt
->goto_label
->ident
->name
,
396 __process_continues();
398 } else if (stmt
->goto_label
&&
399 stmt
->goto_label
->type
== SYM_LABEL
&&
400 stmt
->goto_label
->ident
) {
401 __save_gotos(stmt
->goto_label
->ident
->name
);
408 __split_expr(stmt
->asm_string
);
409 //__split_expr(stmt->asm_outputs);
410 //__split_expr(stmt->asm_inputs);
411 //__split_expr(stmt->asm_clobbers);
416 __split_expr(stmt
->range_expression
);
417 __split_expr(stmt
->range_low
);
418 __split_expr(stmt
->range_high
);
423 static void split_expr_list(struct expression_list
*expr_list
)
425 struct expression
*expr
;
426 FOR_EACH_PTR(expr_list
, expr
) {
428 } END_FOR_EACH_PTR(expr
);
432 static void split_sym(struct symbol
*sym
)
436 if (!(sym
->namespace & NS_SYMBOL
))
439 __pass_to_client(sym
, SYM_HOOK
);
440 __split_statements(sym
->stmt
);
441 __split_expr(sym
->array_size
);
442 split_symlist(sym
->arguments
);
443 split_symlist(sym
->symbol_list
);
444 __split_statements(sym
->inline_stmt
);
445 split_symlist(sym
->inline_symbol_list
);
446 __split_expr(sym
->initializer
);
449 static void split_symlist(struct symbol_list
*sym_list
)
453 FOR_EACH_PTR(sym_list
, sym
) {
455 } END_FOR_EACH_PTR(sym
);
458 static struct expression
*fake_assign_expr(struct symbol
*sym
)
460 struct expression
*e_assign
, *e_symbol
;
462 e_assign
= alloc_expression(sym
->initializer
->pos
, EXPR_ASSIGNMENT
);
463 e_symbol
= alloc_expression(sym
->initializer
->pos
, EXPR_SYMBOL
);
464 e_symbol
->symbol
= sym
;
465 e_symbol
->symbol_name
= sym
->ident
;
466 e_assign
->left
= e_symbol
;
467 e_assign
->right
= sym
->initializer
;
471 static void split_declaration(struct symbol_list
*sym_list
)
474 struct expression
*assign
, *tmp
;
476 FOR_EACH_PTR(sym_list
, sym
) {
477 __pass_to_client(sym
, DECLARATION_HOOK
);
478 __split_expr(sym
->initializer
);
479 if(sym
->initializer
) {
480 assign
= fake_assign_expr(sym
);
481 __pass_to_client(assign
, ASSIGNMENT_HOOK
);
482 tmp
= strip_expr(assign
->right
);
483 if (tmp
->type
== EXPR_CALL
)
484 __pass_to_client(assign
, CALL_ASSIGNMENT_HOOK
);
487 } END_FOR_EACH_PTR(sym
);
490 static void split_functions(struct symbol_list
*sym_list
)
494 FOR_EACH_PTR(sym_list
, sym
) {
495 struct symbol
*base_type
;
496 base_type
= get_base_type(sym
);
497 if (sym
->type
== SYM_NODE
&& base_type
->type
== SYM_FN
) {
500 line_func_start
= base_type
->stmt
->pos
.line
;
502 cur_func
= sym
->ident
->name
;
503 __smatch_lineno
= sym
->pos
.line
;
504 sm_debug("new function: %s\n", cur_func
);
505 if (option_two_passes
) {
509 __pass_to_client(sym
, FUNC_DEF_HOOK
);
510 __split_statements(base_type
->stmt
);
516 __pass_to_client(sym
, FUNC_DEF_HOOK
);
517 __split_statements(base_type
->stmt
);
518 __pass_to_client(sym
, END_FUNC_HOOK
);
522 free_data_info_allocs();
523 free_expression_stack(&switch_expr_stack
);
525 __pass_to_client(sym
, BASE_HOOK
);
527 } END_FOR_EACH_PTR(sym
);
528 __pass_to_client_no_data(END_FILE_HOOK
);
531 void smatch (int argc
, char **argv
)
534 struct string_list
*filelist
= NULL
;
535 struct symbol_list
*sym_list
;
538 printf("Usage: smatch [--debug] <filename.c>\n");
541 sparse_initialize(argc
, argv
, &filelist
);
542 FOR_EACH_PTR_NOTAG(filelist
, filename
) {
543 sym_list
= __sparse(filename
);
544 split_functions(sym_list
);
545 } END_FOR_EACH_PTR_NOTAG(filename
);