[17479] in Kerberos_V5_Development
Re: Proposed platform assumption changes
daemon@ATHENA.MIT.EDU (Nico Williams)
Sun Jan 29 15:17:19 2012
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Date: Sun, 29 Jan 2012 14:17:14 -0600
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From: Nico Williams <nico@cryptonector.com>
To: ghudson@mit.edu
Cc: krbdev@mit.edu
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On Fri, Jan 27, 2012 at 5:55 PM, <ghudson@mit.edu> wrote:
> * Named structure initializers appear to be a favorite C99 feature;
> we've had three separate cases in the past year of people submitting
> code using them and having to ask for it to be changed.
> Unfortunately, it's not supported in MSVC, and there's no pretty way
> of wrapping them to make it work there. We could consider changing
> our Windows build to use mingw, but that would be a lot of work and
> might present other issues.
I just tried the following macro for dealing with this. It works, and
in particular cscope finds the initializers when I search by struct
field name -- a critical feature of C99 designated initializers, IMO.
I posted it as an answer on stackoverflow too (I was looking for this,
didn't find it). This does require building with a C99 compiler for
checking correctness, but MIT krb5 already does that anyways, but a
variant that includes the struct name as a macro argument would allow
for a script to check correctness if that were important.
/*
* Macro for C99 designated initializer -> C89/90 non-designated initializer
*
* Tested. Works with MSVC if you undefine
HAVE_DESIGNATED_INITIALIZERS. Cscope also
* groks this.
*
* ("SFINIT" == struct field init, but really, it can be used for
array initializers too.)
*/
#ifdef HAVE_DESIGNATED_INITIALIZERS
#define SFINIT(f, v) f = v
#else
#define SFINIT(f, v) v
#endif
struct t {
char f1;
int f2;
double f3;
};
struct t t = {
SFINIT(.f1, 'a'),
SFINIT(.f2, 42),
SFINIT(.f3, 8.13)
};
Cheers,
Nico
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