1.3. Preprocessing and conditional compilation
1.3 Preprocessing and conditional compilation
Many Fortran compilers including GNU Fortran allow passing the source code through a C preprocessor (CPP; sometimes also called the Fortran preprocessor, FPP) to allow for conditional compilation. In the case of GNU Fortran, this is the GNU C Preprocessor in the traditional mode. On systems with case-preserving file names, the preprocessor is automatically invoked if the filename extension is .F
, .FOR
, .FTN
, .fpp
, .FPP
, .F90
, .F95
, .F03
or .F08
. To manually invoke the preprocessor on any file, use -cpp
, to disable preprocessing on files where the preprocessor is run automatically, use -nocpp
.
If a preprocessed file includes another file with the Fortran INCLUD