1/*
2 * Copyright (C) 2012 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 "scope.h"
19#include "smatch.h"
20#include "smatch_slist.h"
21#include "smatch_expression_stacks.h"
22
23static int my_id;
24
25static struct string_list *ignored_macros;
26static struct position old_pos;
27
28static struct smatch_state *alloc_my_state(struct expression *expr)
29{
30	struct smatch_state *state;
31	char *name;
32
33	expr = strip_expr(expr);
34	name = expr_to_str(expr);
35	if (!name)
36		return NULL;
37
38	state = __alloc_smatch_state(0);
39	state->name = alloc_sname(name);
40	free_string(name);
41	state->data = expr;
42	return state;
43}
44
45static int defined_inside_macro(struct position macro_pos, struct expression *expr)
46{
47	char *name;
48	struct symbol *sym;
49	int ret = 0;
50
51	name = expr_to_var_sym(expr, &sym);
52	if (!name || !sym)
53		goto free;
54	if (!sym->scope || !sym->scope->token)
55		goto free;
56	if (positions_eq(macro_pos, sym->scope->token->pos))
57		ret = 1;
58free:
59	free_string(name);
60	return ret;
61}
62
63static int affected_inside_macro_before(struct expression *expr)
64{
65	struct sm_state *sm;
66	struct sm_state *tmp;
67	struct expression *old_mod;
68
69	sm = get_sm_state_expr(my_id, expr);
70	if (!sm)
71		return 0;
72
73	FOR_EACH_PTR(sm->possible, tmp) {
74		old_mod = tmp->state->data;
75		if (!old_mod)
76			continue;
77		if (positions_eq(old_mod->pos, expr->pos))
78			return 1;
79	} END_FOR_EACH_PTR(tmp);
80	return 0;
81}
82
83static int is_ignored_macro(const char *macro)
84{
85	char *tmp;
86
87	FOR_EACH_PTR(ignored_macros, tmp) {
88		if (!strcmp(tmp, macro))
89			return 1;
90	} END_FOR_EACH_PTR(tmp);
91	return 0;
92}
93
94static void match_unop(struct expression *raw_expr)
95{
96	struct expression *expr;
97	char *macro, *name;
98
99	if (raw_expr->op != SPECIAL_INCREMENT && raw_expr->op != SPECIAL_DECREMENT)
100		return;
101
102	macro = get_macro_name(raw_expr->pos);
103	if (!macro)
104		return;
105
106	expr = strip_expr(raw_expr->unop);
107
108	if (defined_inside_macro(expr->pos, expr))
109		return;
110
111	if (is_ignored_macro(macro))
112		return;
113
114	if (!affected_inside_macro_before(expr)) {
115		set_state_expr(my_id, expr, alloc_my_state(expr));
116		old_pos = expr->pos;
117		return;
118	}
119
120	if (!positions_eq(old_pos, expr->pos))
121		return;
122
123	name = expr_to_str(raw_expr);
124	sm_warning("side effect in macro '%s' doing '%s'",
125		macro, name);
126	free_string(name);
127}
128
129static void match_stmt(struct statement *stmt)
130{
131	if (!positions_eq(old_pos, stmt->pos))
132		old_pos.line = 0;
133}
134
135static void register_ignored_macros(void)
136{
137	struct token *token;
138	char *macro;
139	char name[256];
140
141	snprintf(name, 256, "%s.ignore_side_effects", option_project_str);
142
143	token = get_tokens_file(name);
144	if (!token)
145		return;
146	if (token_type(token) != TOKEN_STREAMBEGIN)
147		return;
148	token = token->next;
149	while (token_type(token) != TOKEN_STREAMEND) {
150		if (token_type(token) != TOKEN_IDENT)
151			return;
152		macro = alloc_string(show_ident(token->ident));
153		add_ptr_list(&ignored_macros, macro);
154		token = token->next;
155	}
156	clear_token_alloc();
157}
158
159void check_macro_side_effects(int id)
160{
161	my_id = id;
162
163	if (!option_spammy)
164		return;
165
166	set_dynamic_states(my_id);
167	add_hook(&match_unop, OP_HOOK);
168	add_hook(&match_stmt, STMT_HOOK);
169	register_ignored_macros();
170}
171