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 /*
19 * If you have code like:
20 * do {
21 * if (xxx)
22 * continue;
23 * while (0);
24 *
25 * Then the continue is equivalent of a break. So what was really intended?
26 */
27
28 #include "smatch.h"
29 #include "smatch_slist.h"
30
31 static int my_id;
32
33 static struct statement_list *iterator_stack;
34
is_do_while_zero(struct statement * stmt)35 static int is_do_while_zero(struct statement *stmt)
36 {
37 if (!stmt->iterator_post_condition)
38 return 0;
39 if (!expr_is_zero(stmt->iterator_post_condition))
40 return 0;
41 return 1;
42 }
43
push_statement(struct statement_list ** stack,struct statement * stmt)44 static void push_statement(struct statement_list **stack, struct statement *stmt)
45 {
46 add_ptr_list(stack, stmt);
47 }
48
pop_statement(struct statement_list ** stack)49 static void pop_statement(struct statement_list **stack)
50 {
51 delete_ptr_list_last((struct ptr_list **)stack);
52 }
53
inside_do_while_zero(void)54 static int inside_do_while_zero(void)
55 {
56 struct statement *stmt;
57
58 stmt = last_ptr_list((struct ptr_list *)iterator_stack);
59 return !!stmt;
60 }
61
loop_is_macro(void)62 static int loop_is_macro(void)
63 {
64 struct statement *stmt;
65
66 stmt = last_ptr_list((struct ptr_list *)iterator_stack);
67 if (!stmt)
68 return 0;
69 if (get_macro_name(stmt->iterator_post_condition->pos))
70 return 1;
71 return 0;
72 }
73
match_stmt(struct statement * stmt)74 static void match_stmt(struct statement *stmt)
75 {
76 if (stmt->type != STMT_ITERATOR)
77 return;
78
79 if (is_do_while_zero(stmt)) {
80 push_statement(&iterator_stack, stmt);
81 } else
82 push_statement(&iterator_stack, NULL);
83 }
84
match_stmt_after(struct statement * stmt)85 static void match_stmt_after(struct statement *stmt)
86 {
87 if (stmt->type != STMT_ITERATOR)
88 return;
89
90 pop_statement(&iterator_stack);
91 }
92
match_inline_start(struct expression * expr)93 static void match_inline_start(struct expression *expr)
94 {
95 push_statement(&iterator_stack, NULL);
96 }
97
match_inline_end(struct expression * expr)98 static void match_inline_end(struct expression *expr)
99 {
100 pop_statement(&iterator_stack);
101 }
102
match_continue(struct statement * stmt)103 static void match_continue(struct statement *stmt)
104 {
105 if (stmt->type != STMT_GOTO)
106 return;
107
108 if (!stmt->goto_label || stmt->goto_label->type != SYM_NODE)
109 return;
110 if (strcmp(stmt->goto_label->ident->name, "continue") != 0)
111 return;
112 if (!inside_do_while_zero())
113 return;
114 if (loop_is_macro())
115 return;
116 sm_warning("continue to end of do { ... } while(0); loop");
117 }
118
check_continue_vs_break(int id)119 void check_continue_vs_break(int id)
120 {
121 my_id = id;
122 add_hook(&match_stmt, STMT_HOOK);
123 add_hook(&match_stmt_after, STMT_HOOK_AFTER);
124 add_hook(&match_inline_start, INLINE_FN_START);
125 add_hook(&match_inline_end, INLINE_FN_END);
126
127 add_hook(&match_continue, STMT_HOOK);
128 }
129