Re: justification for AC_LANG_ASSERT?

[Steven G. Johnson]

Akim Demaille wrote:
> Yes, but again, some dummies ---such as me---, will really believe FC
> is polymorphic wrt the Fortran flavor.

Akim, it's not that you're "dumb," but your use of the macros in the 
test program is *extremely atypical*.  You weren't actually *using* the 
macros for anything, you just wanted to call them in order to test them. 
 There was no reason for you to even think very closely about what the 
macro is for---you're not doing any Fortran programming, after all 
(lucky you).  On the other hand, when a user wants to call, say, 
AC_FC_FREEFORM, it will be because she actually has free-form Fortran 90 
source code or similar, and is therefore not using legacy Fortran 77.

I think it's a mistake to make judgements about usability from such an 
artificial circumstance.

> Not if you consider that this is only the beginning.  We have to start
> somewhere, and the fact that there are two flavors of Fortran
> emphasizes that need.

Akim, you've chosen a bad example to illustrate the "need": the two 
macros you chose to require AC_PUSH/POP are meaningful *only* for 
"modern" Fortran, not the legacy Fortran 77 flavor.

The use for AC_PUSH/POP should be for macros, like AC_LANG_COMPILER, 
that are polymorphic over the current language.  In this case, the 
PUSH/POP actually adds some semantic content.

This does not apply for macros that are language-specific, and by 
definition any macro that uses AC_LANG_ASSERT is language-specific.

Steven