[PATCH] cocci: detect useless free(3) calls

From: René Scharfe <l.s.r@web.de>
Date: Feb 11, 2017, 13:58 UTC
Message-ID: <7e10f934-f084-ceb4-00eb-b75cdb01886b@web.de>

Add a semantic patch for removing checks that cause free(3) to only be called with a NULL pointer, as that must be a programming mistake.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
No cases are found in master or next, but 1d263b93 (bisect--helper:
`bisect_next_check` & bisect_voc shell function in C) introduced four
of them to pu.

 contrib/coccinelle/free.cocci | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/contrib/coccinelle/free.cocci b/contrib/coccinelle/free.cocci
index e28213161a..c03ba737e5 100644
--- a/contrib/coccinelle/free.cocci
+++ b/contrib/coccinelle/free.cocci
@@ -3,3 +3,9 @@ expression E;
 @@
 - if (E)
   free(E);
+
+@@
+expression E;
+@@
+- if (!E)
+  free(E);

-- 
2.11.1