1/// Compare pointer-typed values to NULL rather than 0
2///
3//# This makes an effort to choose between !x and x == NULL.  !x is used
4//# if it has previously been used with the function used to initialize x.
5//# This relies on type information.  More type information can be obtained
6//# using the option -all_includes and the option -I to specify an
7//# include path.
8//
9// Confidence: High
10// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.  GPLv2.
11// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.  GPLv2.
12// URL: http://coccinelle.lip6.fr/
13// Comments:
14// Options:
15
16virtual patch
17virtual context
18virtual org
19virtual report
20
21@initialize:ocaml@
22let negtable = Hashtbl.create 101
23
24@depends on patch@
25expression *E;
26identifier f;
27@@
28
29(
30  (E = f(...)) ==
31- 0
32+ NULL
33|
34  (E = f(...)) !=
35- 0
36+ NULL
37|
38- 0
39+ NULL
40  == (E = f(...))
41|
42- 0
43+ NULL
44  != (E = f(...))
45)
46
47
48@t1 depends on !patch@
49expression *E;
50identifier f;
51position p;
52@@
53
54(
55  (E = f(...)) ==
56* 0@p
57|
58  (E = f(...)) !=
59* 0@p
60|
61* 0@p
62  == (E = f(...))
63|
64* 0@p
65  != (E = f(...))
66)
67
68@script:python depends on org@
69p << t1.p;
70@@
71
72coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
73
74@script:python depends on report@
75p << t1.p;
76@@
77
78coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
79
80// Tests of returned values
81
82@s@
83identifier f;
84expression E,E1;
85@@
86
87 E = f(...)
88 ... when != E = E1
89 !E
90
91@script:ocaml depends on s@
92f << s.f;
93@@
94
95try let _ = Hashtbl.find negtable f in ()
96with Not_found -> Hashtbl.add negtable f ()
97
98@ r disable is_zero,isnt_zero exists @
99expression *E;
100identifier f;
101@@
102
103E = f(...)
104...
105(E == 0
106|E != 0
107|0 == E
108|0 != E
109)
110
111@script:ocaml@
112f << r.f;
113@@
114
115try let _ = Hashtbl.find negtable f in ()
116with Not_found -> include_match false
117
118// This rule may lead to inconsistent path problems, if E is defined in two
119// places
120@ depends on patch disable is_zero,isnt_zero @
121expression *E;
122expression E1;
123identifier r.f;
124@@
125
126E = f(...)
127<...
128(
129- E == 0
130+ !E
131|
132- E != 0
133+ E
134|
135- 0 == E
136+ !E
137|
138- 0 != E
139+ E
140)
141...>
142?E = E1
143
144@t2 depends on !patch disable is_zero,isnt_zero @
145expression *E;
146expression E1;
147identifier r.f;
148position p1;
149position p2;
150@@
151
152E = f(...)
153<...
154(
155* E == 0@p1
156|
157* E != 0@p2
158|
159* 0@p1 == E
160|
161* 0@p1 != E
162)
163...>
164?E = E1
165
166@script:python depends on org@
167p << t2.p1;
168@@
169
170coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0, suggest !E")
171
172@script:python depends on org@
173p << t2.p2;
174@@
175
176coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
177
178@script:python depends on report@
179p << t2.p1;
180@@
181
182coccilib.report.print_report(p[0], "WARNING comparing pointer to 0, suggest !E")
183
184@script:python depends on report@
185p << t2.p2;
186@@
187
188coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
189
190@ depends on patch disable is_zero,isnt_zero @
191expression *E;
192@@
193
194(
195  E ==
196- 0
197+ NULL
198|
199  E !=
200- 0
201+ NULL
202|
203- 0
204+ NULL
205  == E
206|
207- 0
208+ NULL
209  != E
210)
211
212@ t3 depends on !patch disable is_zero,isnt_zero @
213expression *E;
214position p;
215@@
216
217(
218* E == 0@p
219|
220* E != 0@p
221|
222* 0@p == E
223|
224* 0@p != E
225)
226
227@script:python depends on org@
228p << t3.p;
229@@
230
231coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
232
233@script:python depends on report@
234p << t3.p;
235@@
236
237coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
238