On Fri, May 08, 2020 at 08:57:09AM -0700, Junio C Hamano wrote:
> Eric Sunshine <sunshine@xxxxxxxxxxxxxx> writes:
> > This talks only about '=='.
>
> Yup. The text would need a matching change, though.
Here's a re-roll with the necessary changes.
> > if (!ptr)
> > BUG("...");
> > if (cnt)
> > foo(ptr, cnt);
>
> Or more succinctly:
>
> if (!ptr || cnt)
> BUG("we must have an empty array at this point");
I considered that but thought it might be too "cute", however, seeing
it written out, it looks fine, so I used it in the re-roll.
> > Also, would you want to talk about not comparing against NUL character?
>
> Yeah, it might be worth saying it explicitly. I dunno.
Rather than giving this a separate example in the re-roll, I just
mentioned '\0' in the text.
--- >8 ---
From: Junio C Hamano <gitster@xxxxxxxxx>
Subject: [PATCH] CodingGuidelines: do not ==/!= compare with 0 or '\0' or NULL
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
Signed-off-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx>
---
Documentation/CodingGuidelines | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 390ceece52..6dfc47ed7d 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -236,6 +236,18 @@ For C programs:
while( condition )
func (bar+1);
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate a
+ counted array ptr that has cnt elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
- We avoid using braces unnecessarily. I.e.
if (bla) {
--
2.26.2.717.g5cccb0e1a8
