Re: [PATCH] refactor various if (x) FREE_AND_NULL(x) to just FREE_AND_NULL(x)

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 17, 2018, 17:07 UTC
Message-ID: <xmqqlg94c46f.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <xmqqpnyhaq93.fsf@gitster-ct.c.googlers.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 8 quoted lines

> It is a bit sad that
>
> 	- if (E)
> 	  FREE_AND_NULL(E);
>
> is not sufficient to catch it.  Shouldn't we be doing the same for
> regular free(E) as well?  IOW, like the attached patch.
> ...

And revised even more to also spell "E" as "E != NULL" (and "!E" as "E == NULL"), which seems to make a difference, which is even more sad. I do not want to wonder if I have to also add "NULL == E" and other variants, so I'll stop here.

 contrib/coccinelle/free.cocci | 60 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/contrib/coccinelle/free.cocci b/contrib/coccinelle/free.cocci
index 4490069df9..29ca98796f 100644
--- a/contrib/coccinelle/free.cocci
+++ b/contrib/coccinelle/free.cocci
@@ -16,3 +16,63 @@ expression E;
 - free(E);
 + FREE_AND_NULL(E);
 - E = NULL;
+
+@@
+expression E;
+@@
+- if (E)
+  FREE_AND_NULL(E);
+
+@@
+expression E;
+@@
+- if (E != NULL)
+  free(E);
+
+@@
+expression E;
+@@
+- if (E == NULL)
+  free(E);
+
+@@
+expression E;
+@@
+- if (E != NULL)
+  FREE_AND_NULL(E);
+
+@@
+expression E;
+@@
+- if (E) { free(E); }
++ free(E);
+
+@@
+expression E;
+@@
+- if (!E) { free(E); }
++ free(E);
+
+@@
+expression E;
+@@
+- if (E) { FREE_AND_NULL(E); }
++ FREE_AND_NULL(E);
+
+@@
+expression E;
+@@
+- if (E != NULL) { free(E); }
++ free(E);
+
+@@
+expression E;
+@@
+- if (E == NULL) { free(E); }
++ free(E);
+
+@@
+expression E;
+@@
+- if (E != NULL) { FREE_AND_NULL(E); }
++ FREE_AND_NULL(E);