Re: [PATCH] Fix a warning (on cygwin) to allow -Werror

From: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Date: Aug 28, 2008, 16:09 UTC
Message-ID: <48B6CD9F.6020302@ramsay1.demon.co.uk>
In-Reply-To: <48B508F0.70402@viscovery.net>

Johannes Sixt wrote:

Show 11 quoted lines

> Ramsay Jones schrieb:
>> Also, I noticed that git_ntohl() is still defined in compat/mingw.h; is this
>> still required?  It's not a problem, just curious! (I don't have mingw
>> installed, so I can't test myself)
> 
> Yes, it's still needed. The reason is that on Windows ntohl() returns
> 'unsigned long', and then gcc warns about
> 
> sha1_file.c:700: warning: unsigned int format, u_long arg (arg 3)
> 
> git_ntohl() is the workaround.

OK, Thanks.

Ah, yes, everything works on cygwin and Linux because:

                             Linux           Cygwin
    ntohl() returns:         uint32_t        uint32_t
    uint32_t typedef-ed as:  unsigned int    unsigned long
    PRIu32 #define-d as:     "u"             "lu"

So, I suspect (IOW I am guessing that) mingw must have:

    ntohl() returns:         unsigned long (well u_long anyway)
    uint32_t typedef-ed as:  unsigned int
    PRIu32 #define-d ad:     "u"

(I've just noticed that you are not #include-ing inttypes.h, so you are relying on the PRIu32 defined in git-compat-util.h)

If the above is true, then well, ... Bummer ;-)

I suppose a (very) slight improvement would be to change the return type of your git_ntohl() wrapper to uint32_t. (But we are talking very slight ;-)

ATB,

Ramsay Jones