xref: /illumos-gate/usr/src/tools/smatch/src/smatch_param_used.c (revision a28480febf31f0e61debac062a55216a98a05a92)
1 /*
2  * Copyright (C) 2015 Oracle.
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 #include "smatch.h"
19 #include "smatch_slist.h"
20 
21 static int my_id;
22 
23 static struct stree *used_stree;
24 static struct stree_stack *saved_stack;
25 
26 STATE(used);
27 
28 static void get_state_hook(int owner, const char *name, struct symbol *sym)
29 {
30 	int arg;
31 
32 	if (!option_info)
33 		return;
34 
35 	if (__in_fake_assign || __in_fake_parameter_assign || __in_function_def || __in_unmatched_hook)
36 		return;
37 
38 	arg = get_param_num_from_sym(sym);
39 	if (arg < 0)
40 		return;
41 	if (param_was_set_var_sym(name, sym))
42 		return;
43 	set_state_stree(&used_stree, my_id, name, sym, &used);
44 }
45 
46 static void set_param_used(struct expression *call, struct expression *arg, char *key, char *unused)
47 {
48 	struct symbol *sym;
49 	char *name;
50 	int arg_nr;
51 
52 	if (!option_info)
53 		return;
54 
55 	name = get_variable_from_key(arg, key, &sym);
56 	if (!name || !sym)
57 		goto free;
58 
59 	arg_nr = get_param_num_from_sym(sym);
60 	if (arg_nr < 0)
61 		goto free;
62 	if (param_was_set_var_sym(name, sym))
63 		goto free;
64 	set_state_stree(&used_stree, my_id, name, sym, &used);
65 free:
66 	free_string(name);
67 }
68 
69 static void process_states(void)
70 {
71 	struct sm_state *tmp;
72 	int arg;
73 	const char *name;
74 
75 	FOR_EACH_SM(used_stree, tmp) {
76 		arg = get_param_num_from_sym(tmp->sym);
77 		if (arg < 0)
78 			continue;
79 		name = get_param_name(tmp);
80 		if (!name)
81 			continue;
82 		if (is_recursive_member(name))
83 			continue;
84 
85 		if (is_ignored_kernel_data(name))
86 			continue;
87 
88 		sql_insert_return_implies(PARAM_USED, arg, name, "");
89 	} END_FOR_EACH_SM(tmp);
90 
91 	free_stree(&used_stree);
92 }
93 
94 static void match_function_def(struct symbol *sym)
95 {
96 	free_stree(&used_stree);
97 }
98 
99 static void match_save_states(struct expression *expr)
100 {
101 	push_stree(&saved_stack, used_stree);
102 	used_stree = NULL;
103 }
104 
105 static void match_restore_states(struct expression *expr)
106 {
107 	free_stree(&used_stree);
108 	used_stree = pop_stree(&saved_stack);
109 }
110 
111 void register_param_used(int id)
112 {
113 	my_id = id;
114 
115 	add_hook(&match_function_def, FUNC_DEF_HOOK);
116 
117 	add_get_state_hook(&get_state_hook);
118 
119 	add_hook(&match_save_states, INLINE_FN_START);
120 	add_hook(&match_restore_states, INLINE_FN_END);
121 
122 	select_return_implies_hook(PARAM_USED, &set_param_used);
123 	all_return_states_hook(&process_states);
124 }
125