Coccinelle: Add iterators/itnull.cocci

Many iterators have the property that the first argument is always bound
to a real list element, never NULL.  False positives arise for some
iterators that do not have this property, or in cases when the loop
cursor is reassigned.  The latter should only happen when the matched
code is on the way to a loop exit (break, goto, or return).

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
This commit is contained in:
Nicolas Palix 2010-08-24 17:39:02 +02:00 committed by Michal Marek
parent 4045159253
commit afc48a82fa

View File

@ -0,0 +1,58 @@
/// Many iterators have the property that the first argument is always bound
/// to a real list element, never NULL. False positives arise for some
/// iterators that do not have this property, or in cases when the loop
/// cursor is reassigned. The latter should only happen when the matched
/// code is on the way to a loop exit (break, goto, or return).
///
// Confidence: Moderate
// Copyright: (C) 2010 Nicolas Palix, DIKU. GPLv2.
// Copyright: (C) 2010 Julia Lawall, DIKU. GPLv2.
// Copyright: (C) 2010 Gilles Muller, INRIA/LiP6. GPLv2.
// URL: http://coccinelle.lip6.fr/
// Comments:
// Options: -no_includes -include_headers
virtual patch
@@
iterator I;
expression x,E,E1,E2;
statement S,S1,S2;
@@
I(x,...) { <...
(
- if (x == NULL && ...) S
|
- if (x != NULL || ...)
S
|
- (x == NULL) ||
E
|
- (x != NULL) &&
E
|
- (x == NULL && ...) ? E1 :
E2
|
- (x != NULL || ...) ?
E1
- : E2
|
- if (x == NULL && ...) S1 else
S2
|
- if (x != NULL || ...)
S1
- else S2
|
+ BAD(
x == NULL
+ )
|
+ BAD(
x != NULL
+ )
)
...> }