https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97031
--- Comment #3 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Sun, Sep 13, 2020 at 08:02:01AM +0000, jean-pierre.flam...@univ-lille.fr wrote: > > I just noticed that cpp recognizes the extensions .fpp .F and other uppercase > extensions. > This is why I added -cpp in the gfortran command (otherwise I have a > diagnostic > because of #ifdef's > > I have renamed my file with the .fpp extension; with "-cpp" in the gfortran > submission I get the same errors. > > If I compile the file with extension *.f or .fpp without -cpp > > 1) the compilation has no error > 2) a #ifdef...#endif is recognized even with a .f extension, without -cpp, in > my simple example, (I should check that the directive really is taken into > account !) > 3) IF I compile my full project in a makefile, the absence of "-cpp" in the > gfortran command induces > a "Illegal preprocessor directive" error in all the routines having that > #ifdef...#endif > I don't quite follow you. But, it come down to gfortran uses the C pre-processor when asked to pre-process a file. If you have a C language construct such as '/*' in your Fortran code it will cause problems.
