Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2"

[Paul Eggert]

On 05/09/13 08:24, Zack Weinberg wrote:
> (That said, I've never been clear myself on why CFLAGS and CPPFLAGS
> *are* separate, except possibly the now-long-obsolete historical
> reason that some traditional preprocessors didn't accept arbitrary
> compiler options.)

I think that's basically it, yes.  It used to be that some compilers
didn't have an -E option, so that one had to invoke the preprocessors
directly, and they rejected options like -O2.  Nowadays I expect
this problem is no longer relevant.