The gfortran command supports all the options supported by the gcc command. Only options specific to gfortran are documented here.
Gfortran is not yet a fully conformant Fortran 95 compiler. It can generate code for most constructs and expressions, but work remains to be done. In particular, there are known deficiencies with ENTRY, NAMELIST, and sophisticated use of MODULES, POINTERS and DERIVED TYPES. For those whose Fortran codes conform to either the Fortran 77 standard or the GNU Fortran 77 language, we recommend to use g77 from GCC 3.4. We recommend that distributors continue to provide packages of g77-3.4 until we announce that gfortran fully replaces g77. The gfortran developers welcome any feedback on user experience with gfortran at firstname.lastname@example.org.
See GCC Command Options, for information on the non-Fortran-specific aspects of the gcc command (and, therefore, the gfortran command).
All gcc and gfortran options are accepted both by gfortran and by gcc (as well as any other drivers built at the same time, such as g++), since adding gfortran to the gcc distribution enables acceptance of gfortran options by all of the relevant drivers.
In some cases, options have positive and negative forms; the negative form of -ffoo would be -fno-foo. This manual documents only one of these two forms, whichever one is not the default.