Re: [PATCH] AC_PROG_CC_C99 should not use stdbool.h

[Lasse Collin]

On 2009-03-01 Andreas Schwab wrote:
> Lasse Collin <address@hidden> writes:
> > AC_PROG_CC_C99 doesn't work on systems which have C99 compiler but
> > non-C99 libc which lacks stdbool.h.
>
> A C99 compiler that does not provide <stdlib.h> is not a conforming
> implementation.  That header is part of the set of headers that a
> freestanding implementation must provide.

That's correct about stdbool.h, but I would expect Autoconf to target 
real-world situations instead of what standards require, since many 
systems don't follow standards very strictly.

For example, C99 requires support for stdint.h in freestanding 
implementations. Thus, if we strictly followed the standards, it would 
be fine to have #include <stdint.h> in AC_PROG_CC_C99. But even GCC 
doesn't provide stdint.h (it relies on libc providing it), so checking 
for stdint.h would make AC_PROG_CC_C99 reject GCC as a C99 compiler on 
systems whose libc doesn't provide stdint.h. I would find this 
unacceptable, just like I find it unacceptable to reject the compiler 
due to missing stdbool.h.

-- 
Lasse Collin  |  IRC: Larhzu @ IRCnet & Freenode