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: Requires Coccinelle version 1.0.0-rc20 or later
14// Options:
15
16virtual patch
17virtual context
18virtual org
19virtual report
20
21@initialize:ocaml@
22@@
23let negtable = Hashtbl.create 101
24
25@depends on patch@
26expression *E;
27identifier f;
28@@
29
30(
31  (E = f(...)) ==
32- 0
33+ NULL
34|
35  (E = f(...)) !=
36- 0
37+ NULL
38|
39- 0
40+ NULL
41  == (E = f(...))
42|
43- 0
44+ NULL
45  != (E = f(...))
46)
47
48
49@t1 depends on !patch@
50expression *E;
51identifier f;
52position p;
53@@
54
55(
56  (E = f(...)) ==
57* 0@p
58|
59  (E = f(...)) !=
60* 0@p
61|
62* 0@p
63  == (E = f(...))
64|
65* 0@p
66  != (E = f(...))
67)
68
69@script:python depends on org@
70p << t1.p;
71@@
72
73coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
74
75@script:python depends on report@
76p << t1.p;
77@@
78
79coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
80
81// Tests of returned values
82
83@s@
84identifier f;
85expression E,E1;
86@@
87
88 E = f(...)
89 ... when != E = E1
90 !E
91
92@script:ocaml depends on s@
93f << s.f;
94@@
95
96try let _ = Hashtbl.find negtable f in ()
97with Not_found -> Hashtbl.add negtable f ()
98
99@ r disable is_zero,isnt_zero exists @
100expression *E;
101identifier f;
102@@
103
104E = f(...)
105...
106(E == 0
107|E != 0
108|0 == E
109|0 != E
110)
111
112@script:ocaml@
113f << r.f;
114@@
115
116try let _ = Hashtbl.find negtable f in ()
117with Not_found -> include_match false
118
119// This rule may lead to inconsistent path problems, if E is defined in two
120// places
121@ depends on patch disable is_zero,isnt_zero @
122expression *E;
123expression E1;
124identifier r.f;
125@@
126
127E = f(...)
128<...
129(
130- E == 0
131+ !E
132|
133- E != 0
134+ E
135|
136- 0 == E
137+ !E
138|
139- 0 != E
140+ E
141)
142...>
143?E = E1
144
145@t2 depends on !patch disable is_zero,isnt_zero @
146expression *E;
147expression E1;
148identifier r.f;
149position p1;
150position p2;
151@@
152
153E = f(...)
154<...
155(
156* E == 0@p1
157|
158* E != 0@p2
159|
160* 0@p1 == E
161|
162* 0@p1 != E
163)
164...>
165?E = E1
166
167@script:python depends on org@
168p << t2.p1;
169@@
170
171coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0, suggest !E")
172
173@script:python depends on org@
174p << t2.p2;
175@@
176
177coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
178
179@script:python depends on report@
180p << t2.p1;
181@@
182
183coccilib.report.print_report(p[0], "WARNING comparing pointer to 0, suggest !E")
184
185@script:python depends on report@
186p << t2.p2;
187@@
188
189coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
190
191@ depends on patch disable is_zero,isnt_zero @
192expression *E;
193@@
194
195(
196  E ==
197- 0
198+ NULL
199|
200  E !=
201- 0
202+ NULL
203|
204- 0
205+ NULL
206  == E
207|
208- 0
209+ NULL
210  != E
211)
212
213@ t3 depends on !patch disable is_zero,isnt_zero @
214expression *E;
215position p;
216@@
217
218(
219* E == 0@p
220|
221* E != 0@p
222|
223* 0@p == E
224|
225* 0@p != E
226)
227
228@script:python depends on org@
229p << t3.p;
230@@
231
232coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
233
234@script:python depends on report@
235p << t3.p;
236@@
237
238coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
239