On Sat, 2 Nov 2002, Andreas Buening wrote: > Not really. If you have preprocessed Fortran files then "finding a > compiler" means "finding a compiler with preprocessing". Otherwise > that compiler is useless (and you should proceed with your search).
If you have C-preprocessed Fortran files, then they are not written in Fortran. I agree that preprocessed Fortran is an important language to support and one for which I would love to see autoconf support added in the future (perhaps via an AC_PROG_FC_CPP macro or whatever), but that's simply not the problem I'm proposing to address right now. > > .f90 or whatever for newer code. Is there any F90+ compiler that doesn't > > interpret .f90 as F90 source?? > > xlf90, IBM's compiler for AIX. It requires -qsuffix=f=f90. Kate Hedstrom pointed out the same problem, grrr... This can be dealt with, though. > > The general problem of finding a flag to force free-format/fixed-format > > interpretation is an issue for another macro, I think. > > This means you need a "database", one different flag for every compiler. Nope. You need a list of possible flags to try, and a test to see if free-format source compiles. Much like AC_PROG_CC_STDC, as I mentioned. > > Ultimately, this sort of thing has to be handled by custom macros, if the > > maintainer needs particular nonstandard language features. Particularly > > common needs might go into the macro repository and from there (maybe) > > make their way into the standard autoconf. > > In other words: You need a "database". Nope, you need tests to see if a particular feature works, by trying to compile/run something with that feature. Much like the rest of autoconf. (That is, you don't need a database of systems and compilers.) > Some compilers (like f95n) try to find out the source file format > (fixed/free) themselves. For a "print *, 'hello, world'" test program > this might work correctly but for a more complicated source file > it might fail. In this case there is no possibility for autoconf to find > out whether that compiler can really handle fixed/free format. Coming up with feature tests can be tricky, but this is not unique to Fortran. It's the story of autoconf: ingenuity triumphing over insanity. =) (Mostly, anyway. Only sometimes we can't distinguish the ingenuity from the insanity.) That said, I appreciate your comments on the variety of compiler quirks we will need to deal with. The odds of the initial AC_PROG_FC macros and friends working right away for all f90+ compilers are approximately zero, but the support will enlarge over time like every other macro. What else can you do? Steven
