cocci: Add script to remove unneeded checks for NULL

NULL can be safely free()'d, but often code checks if a pointer is
non-NULL before free()'ing it. These checks can be automatically
detected and removed.

1 files changed, 26 insertions, 0 deletions

diff --git a/cleanup-free-NULL.cocci b/cleanup-free-NULL.cocci
new file mode 100644
index 0000000..e22dab7
--- /dev/null
+++ b/cleanup-free-NULL.cocci
@@ -0,0 +1,26 @@
+// Remove useless checks for NULL before freeing
+//
+// free (NULL) is a no-op, so there is no need to avoid it
+
+@@
+expression E;
+@@
++ free (E);
++ E = NULL;
+- if (unlikely (E != NULL)) {
+-   free(E);
+(
+-   E = NULL;
+|
+-   E = 0;
+)
+   ...
+- }
+
+@@
+expression E;
+@@
++ free (E);
+- if (unlikely (E != NULL)) {
+-   free (E);
+- }