Heya Ludo,
On Tue 26 May 2009 19:10, l...@gnu.org (Ludovic Courtès) writes:
> "Andy Wingo" <wi...@wingomac.bcn.oblong.net> writes:
>
>> +#if BUILDING_LIBGUILE && HAVE_VISIBILITY
>> +# define SCM_API extern __attribute__((__visibility__("default")))
>> +#elif BUILDING_LIBGUILE && defined _MSC_VER
>
> This should be:
>
> #if defined BUILDING_LIBGUILE && BUILDING_LIBGUILE && HAVE_VISIBILITY
I believe that this is strictly equivalent. Quoth the CPP manual:
#if expression
controlled text
#endif /* expression */
expression is a C expression of integer type, subject to stringent
restrictions. It may contain
* Integer constants.
* Character constants ...
* Arithmetic operators ...
* Macros ...
* Uses of the defined operator ...
* Identifiers that are not macros, which are all considered to be
the number zero. This allows you to write #if MACRO instead of
#ifdef MACRO, if you know that MACRO, when defined, will always
have a nonzero value. Function-like macros used without their
function call parentheses are also treated as zero.
In some contexts this shortcut is undesirable. The -Wundef option
causes GCC to warn whenever it encounters an identifier which is
not a macro in an `#if'.
But I guess that we want to support -Wundef or something, and this is in
a public header, so I suppose you are right :)
> Also, I'd have preferred `_GUILE_WITHIN_GUILE', which is clearly in
> Guile's name space, and is similar to GMP's `__GMP_WITHIN_GMP' ("rule of
> least surprise"). What do you think?
I don't care :) I thought I recalled that Neil wanted something else,
and Bruno had this in the gnulib docs, so I just used that. Please tell
me to change it if you want it changed :-)
Cheers,
Andy
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