1/// Many iterators have the property that the first argument is always bound
2/// to a real list element, never NULL.
3//# False positives arise for some iterators that do not have this property,
4//# or in cases when the loop cursor is reassigned.  The latter should only
5//# happen when the matched code is on the way to a loop exit (break, goto,
6//# or return).
7///
8// Confidence: Moderate
9// Copyright: (C) 2010-2012 Nicolas Palix.  GPLv2.
10// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.  GPLv2.
11// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.  GPLv2.
12// URL: http://coccinelle.lip6.fr/
13// Comments:
14// Options: -no_includes -include_headers
15
16virtual patch
17virtual context
18virtual org
19virtual report
20
21@depends on patch@
22iterator I;
23expression x,E,E1,E2;
24statement S,S1,S2;
25@@
26
27I(x,...) { <...
28(
29- if (x == NULL && ...) S
30|
31- if (x != NULL || ...)
32  S
33|
34- (x == NULL) ||
35  E
36|
37- (x != NULL) &&
38  E
39|
40- (x == NULL && ...) ? E1 :
41  E2
42|
43- (x != NULL || ...) ?
44  E1
45- : E2
46|
47- if (x == NULL && ...) S1 else
48  S2
49|
50- if (x != NULL || ...)
51  S1
52- else S2
53|
54+ BAD(
55  x == NULL
56+ )
57|
58+ BAD(
59  x != NULL
60+ )
61)
62  ...> }
63
64@r depends on !patch exists@
65iterator I;
66expression x,E;
67position p1,p2;
68@@
69
70*I@p1(x,...)
71{ ... when != x = E
72(
73*  x@p2 == NULL
74|
75*  x@p2 != NULL
76)
77  ... when any
78}
79
80@script:python depends on org@
81p1 << r.p1;
82p2 << r.p2;
83@@
84
85cocci.print_main("iterator-bound variable",p1)
86cocci.print_secs("useless NULL test",p2)
87
88@script:python depends on report@
89p1 << r.p1;
90p2 << r.p2;
91@@
92
93msg = "ERROR: iterator variable bound on line %s cannot be NULL" % (p1[0].line)
94coccilib.report.print_report(p2[0], msg)
95