summaryrefslogtreecommitdiff
path: root/scripts/coccinelle/null/badzero.cocci
blob: f597c8007b763b45e8b091c56c2f894521366a2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/// Compare pointer-typed values to NULL rather than 0
///
//# This makes an effort to choose between !x and x == NULL.  !x is used
//# if it has previously been used with the function used to initialize x.
//# This relies on type information.  More type information can be obtained
//# using the option -all_includes and the option -I to specify an
//# include path.
//
// Confidence: High
// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.  GPLv2.
// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.  GPLv2.
// URL: http://coccinelle.lip6.fr/
// Requires: 1.0.0
// Options:

virtual patch
virtual context
virtual org
virtual report

@initialize:ocaml@
@@
let negtable = Hashtbl.create 101

@depends on patch@
expression *E;
identifier f;
@@

(
  (E = f(...)) ==
- 0
+ NULL
|
  (E = f(...)) !=
- 0
+ NULL
|
- 0
+ NULL
  == (E = f(...))
|
- 0
+ NULL
  != (E = f(...))
)


@t1 depends on !patch@
expression *E;
identifier f;
position p;
@@

(
  (E = f(...)) ==
* 0@p
|
  (E = f(...)) !=
* 0@p
|
* 0@p
  == (E = f(...))
|
* 0@p
  != (E = f(...))
)

@script:python depends on org@
p << t1.p;
@@

coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")

@script:python depends on report@
p << t1.p;
@@

coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")

// Tests of returned values

@s@
identifier f;
expression E,E1;
@@

 E = f(...)
 ... when != E = E1
 !E

@script:ocaml depends on s@
f << s.f;
@@

try let _ = Hashtbl.find negtable f in ()
with Not_found -> Hashtbl.add negtable f ()

@ r disable is_zero,isnt_zero exists @
expression *E;
identifier f;
@@

E = f(...)
...
(E == 0
|E != 0
|0 == E
|0 != E
)

@script:ocaml@
f << r.f;
@@

try let _ = Hashtbl.find negtable f in ()
with Not_found -> include_match false

// This rule may lead to inconsistent path problems, if E is defined in two
// places
@ depends on patch disable is_zero,isnt_zero @
expression *E;
expression E1;
identifier r.f;
@@

E = f(...)
<...
(
- E == 0
+ !E
|
- E != 0
+ E
|
- 0 == E
+ !E
|
- 0 != E
+ E
)
...>
?E = E1

@t2 depends on !patch disable is_zero,isnt_zero @
expression *E;
expression E1;
identifier r.f;
position p1;
position p2;
@@

E = f(...)
<...
(
* E == 0@p1
|
* E != 0@p2
|
* 0@p1 == E
|
* 0@p1 != E
)
...>
?E = E1

@script:python depends on org@
p << t2.p1;
@@

coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0, suggest !E")

@script:python depends on org@
p << t2.p2;
@@

coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")

@script:python depends on report@
p << t2.p1;
@@

coccilib.report.print_report(p[0], "WARNING comparing pointer to 0, suggest !E")

@script:python depends on report@
p << t2.p2;
@@

coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")

@ depends on patch disable is_zero,isnt_zero @
expression *E;
@@

(
  E ==
- 0
+ NULL
|
  E !=
- 0
+ NULL
|
- 0
+ NULL
  == E
|
- 0
+ NULL
  != E
)

@ t3 depends on !patch disable is_zero,isnt_zero @
expression *E;
position p;
@@

(
* E == 0@p
|
* E != 0@p
|
* 0@p == E
|
* 0@p != E
)

@script:python depends on org@
p << t3.p;
@@

coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")

@script:python depends on report@
p << t3.p;
@@

coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")