I very much like the idea of having a macro like this, but I worry
about the fact that it creates a file stdbool.h. Suppose that file is
left around from a previous build: won't that possibly screw up the
next build if it doesn't want stdbool.h? Surely the output file
should be removed before the test is run; it should also be removed if
config.status is run.
Also, the shell var STDBOOL_H doesn't seem right: shouldn't it have a
reserved prefix? And I don't see how it's propagated from configure
to config.status.
There also seem to be some m4 quoting issues, as usual....
Some minor quibbles. Please replace:
#ifdef __BEOS__
# undef false
# undef true
#endif
with:
#ifdef false
# undef false
#endif
#ifdef true
# undef true
#endif
so that the code is not BeOS-specific.
The following code seems pretty verbose:
#if false
int A[-1];
#endif
#define b -1
#if true
#undef b
#define b 1
#endif
int B[b];
and also it doesn't check that bool is defined and is a valid type.
Wouldn't the following be shorter and clearer?
bool a1[false || !true ? -1 : 1];
#if !defined false || !true || !defined bool
int a2[-1];
#endif
The documentation is a little unclear and its indexing isn't right.
Here's a suggested rewrite:
@defmac AC_HEADER_STDBOOL (@var{directory})
@acindex HEADER_STDBOOL
If @file{stdbool.h} does not work correctly, create a file
@file{@var{directory}/stdbool.h} (default @file{./stdbool.h}) that
does work. This macro invokes @code{AC_CONFIG_COMMANDS} so it
is an instantiating macro; see @ref{Configuration Actions}.
@end defmac
