1 /*
2 * Copyright (C) 2009 Dan Carpenter.
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 /*
19 * This is not a check. It just saves an struct expression pointer
20 * whenever something is assigned. This can be used later on by other scripts.
21 */
22
23 #include "smatch.h"
24 #include "smatch_slist.h"
25 #include "smatch_extra.h"
26
27 int check_assigned_expr_id;
28 static int my_id;
29 static int link_id;
30
31 static struct expression *skip_mod;
32
undef(struct sm_state * sm,struct expression * mod_expr)33 static void undef(struct sm_state *sm, struct expression *mod_expr)
34 {
35 if (mod_expr == skip_mod)
36 return;
37 set_state(my_id, sm->name, sm->sym, &undefined);
38 }
39
get_assigned_expr(struct expression * expr)40 struct expression *get_assigned_expr(struct expression *expr)
41 {
42 struct smatch_state *state;
43
44 state = get_state_expr(my_id, expr);
45 if (!state)
46 return NULL;
47 return (struct expression *)state->data;
48 }
49
get_assigned_expr_name_sym(const char * name,struct symbol * sym)50 struct expression *get_assigned_expr_name_sym(const char *name, struct symbol *sym)
51 {
52 struct smatch_state *state;
53
54 state = __get_state(my_id, name, sym);
55 if (!state)
56 return NULL;
57 return (struct expression *)state->data;
58 }
59
match_assignment(struct expression * expr)60 static void match_assignment(struct expression *expr)
61 {
62 static struct expression *ignored_expr;
63 struct symbol *left_sym, *right_sym;
64 char *left_name = NULL;
65 char *right_name = NULL;
66
67 if (expr->op != '=')
68 return;
69 if (is_fake_call(expr->right))
70 return;
71 if (__in_fake_struct_assign) {
72 struct range_list *rl;
73
74 if (!get_implied_rl(expr->right, &rl))
75 return;
76 if (is_whole_rl(rl))
77 return;
78 }
79
80 if (expr->left == ignored_expr)
81 return;
82 ignored_expr = NULL;
83 if (__in_fake_parameter_assign)
84 ignored_expr = expr->left;
85
86 left_name = expr_to_var_sym(expr->left, &left_sym);
87 if (!left_name || !left_sym)
88 goto free;
89 set_state(my_id, left_name, left_sym, alloc_state_expr(strip_expr(expr->right)));
90
91 right_name = expr_to_var_sym(expr->right, &right_sym);
92 if (!right_name || !right_sym)
93 goto free;
94
95 store_link(link_id, right_name, right_sym, left_name, left_sym);
96
97 free:
98 free_string(left_name);
99 free_string(right_name);
100 }
101
record_param_assignment(struct expression * expr,int param,char * key,char * value)102 static void record_param_assignment(struct expression *expr, int param, char *key, char *value)
103 {
104 struct expression *arg, *right;
105 struct symbol *sym;
106 char *name;
107 char *p;
108 int right_param;
109
110 while (expr->type == EXPR_ASSIGNMENT)
111 expr = strip_expr(expr->right);
112 if (!expr || expr->type != EXPR_CALL)
113 return;
114
115 p = strstr(value, "[$");
116 if (!p)
117 return;
118
119 p += 2;
120 right_param = strtol(p, &p, 10);
121 if (*p != ']')
122 return;
123
124 arg = get_argument_from_call_expr(expr->args, param);
125 right = get_argument_from_call_expr(expr->args, right_param);
126 if (!right || !arg)
127 return;
128 name = get_variable_from_key(arg, key, &sym);
129 if (!name || !sym)
130 goto free;
131
132 skip_mod = expr;
133 set_state(my_id, name, sym, alloc_state_expr(right));
134 free:
135 free_string(name);
136 }
137
register_assigned_expr(int id)138 void register_assigned_expr(int id)
139 {
140 my_id = check_assigned_expr_id = id;
141 set_dynamic_states(check_assigned_expr_id);
142 add_hook(&match_assignment, ASSIGNMENT_HOOK_AFTER);
143 add_modification_hook(my_id, &undef);
144 select_return_states_hook(PARAM_SET, &record_param_assignment);
145 }
146
register_assigned_expr_links(int id)147 void register_assigned_expr_links(int id)
148 {
149 link_id = id;
150 set_dynamic_states(link_id);
151 db_ignore_states(link_id);
152 set_up_link_functions(my_id, link_id);
153 }
154
155