Re: [PATCH v3] git-compat-util.h: implement a different ARRAY_SIZE macro for for safely deriving the size of array
- From
Jeff King <peff@peff.net>
- Date
- Apr 30, 2015, 17:44 UTC
- Message-ID
- <20150430174440.GC21800@peff.net>
- In-Reply-To
- <xmqqd22l1pkl.fsf@gitster.dls.corp.google.com>
On Thu, Apr 30, 2015 at 10:41:30AM -0700, Junio C Hamano wrote:
Show 28 quoted lines
> Elia Pinto <gitter.spiros@gmail.com> writes:
>
> > +#if defined(__GNUC__) && (__GNUC__ >= 3)
> > +# if GIT_GNUC_PREREQ(3, 1)
> > + /* &arr[0] degrades to a pointer: a different type from an array */
> > +# define BARF_IF_IS_NOT_AN_ARRAY(arr) \
> > + BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(typeof(arr), \
> > + typeof(&(arr)[0])))
> > +# else
> > +# define BARF_IF_IS_NOT_AN_ARRAY(arr) 0
> > +# endif
> [...]
>
> Hmmmmmmmm.
>
> CC ws.o
> ws.c: In function 'parse_whitespace_rule':
> ws.c:46:3: error: unknown type name 'typeof'
> for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
> ^
>
> $ gcc --version
> gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2
> Copyright (C) 2013 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions. There
> is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
> PURPOSE.ISTR that you compile with "-std=c89". typeof was added in c99, I think (and was a GNU extension before that). I wonder if that is fooling the gcc version-check.
-Peff