Re: AC_PROG_CC_C99

[Paul Eggert]

"Steven G. Johnson" <address@hidden> writes:

> As you yourself point out, the purpose of the AC_PROG_CC_C99 macro is
> to discover compiler flags that put the compiler in a C99-ish mode,
> *not* to guarantee that the compiler completely conforms to the [C99]
> standard.

Yes, quite clearly it's a judgment call.  I listed what I considered
to be important C99 features, features that even a half-baked "C99"
compiler would have.  It was not intended to be a comprehensive test
for C99 conformance.  For example, I didn't suggest testing for \U,
since I don't think that's an important feature.  I omitted far more
C99 features than I mentioned.

C99 is a bit trickier than C89, since its takeup is far more slower
and gradual than C89's was.  So it will be a trickier business to come
up with a nice macro.  I gave it my best shot, though.

We can adjust the list of features as needed, based on further
experience.