Re: [RFC PATCH] Move SHA-1 implementation selection into a header file

[Ramsay Jones <ramsay@ramsayjones.plus.com>]

On 14/03/17 20:44, Junio C Hamano wrote:
> OK, then I'll queue this.  The selection still goes to BASIC_CFLAGS
> so the dependencies for re-compilation should be right, I'd think.
> 
> -- >8 --
> From: "brian m. carlson" <sandals@crustytoothpaste.net>
> Date: Sat, 11 Mar 2017 22:28:18 +0000
> Subject: [PATCH] hash.h: move SHA-1 implementation selection into a header file
> 
> Many developers use functionality in their editors that allows for quick
> syntax checks, including warning about questionable constructs.  This
> functionality allows rapid development with fewer errors.  However, such
> functionality generally does not allow the specification of
> project-specific defines or command-line options.
> 
> Since the SHA1_HEADER include is not defined in such a case, developers
> see spurious errors when using these tools.  Furthermore, while using a
> macro as the argument to #include is permitted by C11, it isn't
> permitted by C89 and C99, and there are known implementations which
> reject it.

C99 certainly allows a macro argument to #include (see, 6.10.2-4; there
is also an example in 6.10.2-8).

I can't remember if it's allowed in C89/C90 (I think it is). I only
have immediate access to the C99 and C11 standards (and I can't be
bothered to search), so I can't say for sure.

ATB,
Ramsay Jones