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;
39 void __split_expr(struct expression
*expr
)
44 // printf("%d Debug expr_type %d %s\n", get_lineno(), expr->type, show_special(expr->op));
46 __smatch_lineno
= expr
->pos
.line
;
47 __pass_to_client(expr
, EXPR_HOOK
);
52 __pass_to_client(expr
, OP_HOOK
);
53 __split_expr(expr
->unop
);
56 __split_statements(expr
->statement
);
59 __split_whole_condition(expr
);
62 __merge_true_states();
63 __pop_false_only_stack();
70 __split_expr(expr
->left
);
71 __split_expr(expr
->right
);
73 case EXPR_ASSIGNMENT
: {
74 struct expression
*tmp
;
76 __split_expr(expr
->right
);
77 __pass_to_client(expr
, ASSIGNMENT_HOOK
);
78 tmp
= strip_expr(expr
->right
);
79 if (tmp
->type
== EXPR_CALL
)
80 __pass_to_client(expr
, CALL_ASSIGNMENT_HOOK
);
81 __split_expr(expr
->left
);
85 __pass_to_client(expr
, DEREF_HOOK
);
86 __split_expr(expr
->deref
);
89 __split_expr(expr
->base
);
92 __split_expr(expr
->cast_expression
);
95 /* there isn't anything to pass a client from inside a sizeof() */
97 case EXPR_CONDITIONAL
:
99 __split_whole_condition(expr
->conditional
);
100 __split_expr(expr
->cond_true
);
101 __push_true_states();
102 __use_false_states();
103 __split_expr(expr
->cond_false
);
104 __merge_true_states();
105 __pop_false_only_stack();
108 split_expr_list(expr
->args
);
109 __split_expr(expr
->fn
);
110 __pass_to_client(expr
, FUNCTION_CALL_HOOK
);
112 case EXPR_INITIALIZER
:
113 split_expr_list(expr
->expr_list
);
115 case EXPR_IDENTIFIER
:
116 __split_expr(expr
->ident_expression
);
119 __split_expr(expr
->idx_expression
);
122 __split_expr(expr
->init_expr
);
129 static int is_forever_loop(struct statement
*stmt
)
132 struct expression
*expr
;
134 expr
= strip_expr(stmt
->iterator_pre_condition
);
136 expr
= stmt
->iterator_post_condition
;
138 /* this is a for(;;) loop... */
142 if (expr
->type
== EXPR_VALUE
&& expr
->value
== 1) {
150 static char *get_loop_name(int num
)
154 snprintf(buf
, 255, "-loop%d", num
);
156 return alloc_sname(buf
);;
160 * Pre Loops are while and for loops.
163 static void handle_pre_loop(struct statement
*stmt
)
165 int once_through
; /* we go through the loop at least once */
166 struct sm_state
*extra_state
= NULL
;
170 loop_name
= get_loop_name(loop_num
);
173 __split_statements(stmt
->iterator_pre_statement
);
175 once_through
= implied_condition_true(stmt
->iterator_pre_condition
);
180 __merge_gotos(loop_name
);
181 __split_whole_condition(stmt
->iterator_pre_condition
);
183 extra_state
= __extra_pre_loop_hook_before(stmt
->iterator_pre_statement
);
184 if (option_assume_loops
)
186 __split_statements(stmt
->iterator_statement
);
188 __warn_on_silly_pre_loops();
189 if (is_forever_loop(stmt
)) {
190 __save_gotos(loop_name
);
191 __pop_false_only_stack();
192 /* forever loops don't have an iterator_post_statement */
194 __pop_false_states();
196 } else if (once_through
) {
199 unchanged
= __iterator_unchanged(extra_state
, stmt
->iterator_post_statement
);
200 __split_statements(stmt
->iterator_post_statement
);
201 __save_gotos(loop_name
);
202 __split_whole_condition(stmt
->iterator_pre_condition
);
204 __merge_false_states();
205 if (extra_state
&& unchanged
)
206 __extra_pre_loop_hook_after(extra_state
,
207 stmt
->iterator_post_statement
, stmt
->iterator_pre_condition
);
208 __pop_false_states();
209 __pop_false_only_stack();
210 __pop_false_only_stack();
214 __split_statements(stmt
->iterator_post_statement
);
215 __save_gotos(loop_name
);
216 __merge_false_states();
217 __use_false_only_stack();
223 * Post loops are do {} while();
225 static void handle_post_loop(struct statement
*stmt
)
229 loop_name
= get_loop_name(loop_num
);
234 __merge_gotos(loop_name
);
235 __split_statements(stmt
->iterator_statement
);
237 if (!is_zero(stmt
->iterator_post_condition
))
238 __save_gotos(loop_name
);
240 if (is_forever_loop(stmt
)) {
243 __split_whole_condition(stmt
->iterator_post_condition
);
244 __use_false_states();
247 __pop_false_only_stack();
250 static void print_unreached(struct statement
*stmt
)
254 * GCC insists on a return statement even where it is never
255 * reached. Also BUG() sometimes is a forever loop and
256 * sometimes not so people put code after a BUG(). There
257 * are way to many false positives.
262 if (__path_is_null()) {
264 case STMT_COMPOUND
: /* after a switch before a case stmt */
267 case STMT_DECLARATION
: /* switch(x) { int a; case foo: ... */
270 sm_msg("unreachable code. %d", stmt
->type
);
275 void __split_statements(struct statement
*stmt
)
280 if (out_of_memory()) {
281 static char *printed
= NULL
;
283 if (printed
!= cur_func
)
284 sm_msg("Function too big. Giving up.");
289 __smatch_lineno
= stmt
->pos
.line
;
290 print_unreached(stmt
);
291 __pass_to_client(stmt
, STMT_HOOK
);
293 switch (stmt
->type
) {
294 case STMT_DECLARATION
:
295 split_declaration(stmt
->declaration
);
298 __split_expr(stmt
->ret_value
);
299 __pass_to_client(stmt
, RETURN_HOOK
);
302 case STMT_EXPRESSION
:
303 __split_expr(stmt
->expression
);
305 case STMT_COMPOUND
: {
307 __push_scope_hooks();
308 FOR_EACH_PTR(stmt
->stmts
, s
) {
309 __split_statements(s
);
310 } END_FOR_EACH_PTR(s
);
311 __call_scope_hooks();
315 if (known_condition_true(stmt
->if_conditional
)) {
316 __split_statements(stmt
->if_true
);
319 if (known_condition_false(stmt
->if_conditional
)) {
320 __split_statements(stmt
->if_false
);
323 if (option_known_conditions
&&
324 implied_condition_true(stmt
->if_conditional
)) {
325 sm_msg("info: this condition is true.");
326 __split_statements(stmt
->if_true
);
329 if (option_known_conditions
&&
330 implied_condition_false(stmt
->if_conditional
)) {
331 sm_msg("info: this condition is false.");
332 __split_statements(stmt
->if_false
);
335 __split_whole_condition(stmt
->if_conditional
);
336 __split_statements(stmt
->if_true
);
337 __push_true_states();
338 __use_false_states();
339 __split_statements(stmt
->if_false
);
340 __merge_true_states();
341 __pop_false_only_stack();
344 if (stmt
->iterator_pre_condition
)
345 handle_pre_loop(stmt
);
346 else if (stmt
->iterator_post_condition
)
347 handle_post_loop(stmt
);
349 // these are for(;;) type loops.
350 handle_pre_loop(stmt
);
354 __split_expr(stmt
->switch_expression
);
355 push_expression(&switch_expr_stack
, stmt
->switch_expression
);
356 __save_switch_states(top_expression(switch_expr_stack
));
360 __split_statements(stmt
->switch_statement
);
361 if (!__pop_default())
362 __merge_switches(top_expression(switch_expr_stack
),
366 pop_expression(&switch_expr_stack
);
369 __merge_switches(top_expression(switch_expr_stack
),
370 stmt
->case_expression
);
371 __pass_case_to_client(top_expression(switch_expr_stack
),
372 stmt
->case_expression
);
373 if (!stmt
->case_expression
)
375 __split_expr(stmt
->case_expression
);
376 __split_expr(stmt
->case_to
);
377 __split_statements(stmt
->case_statement
);
381 stmt
->label
->type
== SYM_LABEL
&&
382 stmt
->label
->ident
) {
383 __merge_gotos(stmt
->label
->ident
->name
);
385 __split_statements(stmt
->label_statement
);
388 __split_expr(stmt
->goto_expression
);
389 if (stmt
->goto_label
&& stmt
->goto_label
->type
== SYM_NODE
) {
390 if (!strcmp(stmt
->goto_label
->ident
->name
, "break")) {
392 } else if (!strcmp(stmt
->goto_label
->ident
->name
,
394 __process_continues();
396 } else if (stmt
->goto_label
&&
397 stmt
->goto_label
->type
== SYM_LABEL
&&
398 stmt
->goto_label
->ident
) {
399 __save_gotos(stmt
->goto_label
->ident
->name
);
406 __split_expr(stmt
->asm_string
);
407 //__split_expr(stmt->asm_outputs);
408 //__split_expr(stmt->asm_inputs);
409 //__split_expr(stmt->asm_clobbers);
414 __split_expr(stmt
->range_expression
);
415 __split_expr(stmt
->range_low
);
416 __split_expr(stmt
->range_high
);
421 static void split_expr_list(struct expression_list
*expr_list
)
423 struct expression
*expr
;
424 FOR_EACH_PTR(expr_list
, expr
) {
426 } END_FOR_EACH_PTR(expr
);
430 static void split_sym(struct symbol
*sym
)
434 if (!(sym
->namespace & NS_SYMBOL
))
437 __pass_to_client(sym
, SYM_HOOK
);
438 __split_statements(sym
->stmt
);
439 __split_expr(sym
->array_size
);
440 split_symlist(sym
->arguments
);
441 split_symlist(sym
->symbol_list
);
442 __split_statements(sym
->inline_stmt
);
443 split_symlist(sym
->inline_symbol_list
);
444 __split_expr(sym
->initializer
);
447 static void split_symlist(struct symbol_list
*sym_list
)
451 FOR_EACH_PTR(sym_list
, sym
) {
453 } END_FOR_EACH_PTR(sym
);
456 static void split_declaration(struct symbol_list
*sym_list
)
460 FOR_EACH_PTR(sym_list
, sym
) {
461 __pass_to_client(sym
, DECLARATION_HOOK
);
462 __split_expr(sym
->initializer
);
463 if(sym
->initializer
&& sym
->initializer
->type
== EXPR_CALL
) {
464 __match_initializer_call(sym
);
467 } END_FOR_EACH_PTR(sym
);
470 static void split_functions(struct symbol_list
*sym_list
)
474 FOR_EACH_PTR(sym_list
, sym
) {
475 struct symbol
*base_type
;
476 base_type
= get_base_type(sym
);
477 if (sym
->type
== SYM_NODE
&& base_type
->type
== SYM_FN
) {
479 line_func_start
= base_type
->stmt
->pos
.line
;
481 cur_func
= sym
->ident
->name
;
482 __smatch_lineno
= sym
->pos
.line
;
483 sm_debug("new function: %s\n", cur_func
);
484 if (option_two_passes
) {
488 __pass_to_client(sym
, FUNC_DEF_HOOK
);
489 __split_statements(base_type
->stmt
);
495 __pass_to_client(sym
, FUNC_DEF_HOOK
);
496 __split_statements(base_type
->stmt
);
497 __pass_to_client(sym
, END_FUNC_HOOK
);
501 free_expression_stack(&switch_expr_stack
);
503 __pass_to_client(sym
, BASE_HOOK
);
505 } END_FOR_EACH_PTR(sym
);
506 __pass_to_client_no_data(END_FILE_HOOK
);
509 void smatch (int argc
, char **argv
)
512 struct string_list
*filelist
= NULL
;
513 struct symbol_list
*sym_list
;
516 printf("Usage: smatch [--debug] <filename.c>\n");
519 sparse_initialize(argc
, argv
, &filelist
);
520 FOR_EACH_PTR_NOTAG(filelist
, filename
) {
521 sym_list
= __sparse(filename
);
522 split_functions(sym_list
);
523 } END_FOR_EACH_PTR_NOTAG(filename
);