From afc48a82fafe55dbeeaf7c0d83d29cf279cb1c70 Mon Sep 17 00:00:00 2001
From: Nicolas Palix <npalix@diku.dk>
Date: Tue, 24 Aug 2010 17:39:02 +0200
Subject: [PATCH] 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>
---
 scripts/coccinelle/iterators/itnull.cocci | 58 +++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 scripts/coccinelle/iterators/itnull.cocci

diff --git a/scripts/coccinelle/iterators/itnull.cocci b/scripts/coccinelle/iterators/itnull.cocci
new file mode 100644
index 000000000000..baa4297a4ed1
--- /dev/null
+++ b/scripts/coccinelle/iterators/itnull.cocci
@@ -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
++ )
+)
+  ...> }
\ No newline at end of file