Migration to gfortran

• It is very hard for us to create a port uses fortran90/95. See elmer-mathlibs. This installs F90 compiled blas/lapack for family of elmer ports ONLY, and have many CONFLICTS line.
• gfortran42 (lang/gcc42) is stable enough as gerald@ said, and they fixed numerous bugs!
• g77 is no longer maintained., and also please refer GFORTRAN and G77.
• No object compatibility between G77 and Gfortran (though -ff2c option does)
• Generally faster than G77.
• Cannot set default integer as 8. A workaround exists for G77 but may not work correctly for all cases and never be upstreamed. For 64bit systems like amd64, we cannot use huge array.
• FreeBSD 7 will not ship with Fortran, even though migrating to gcc4(Still I hope).
• Runtime libraries are changed from libg2c to libgfortranbegin and libgfortran.
• Users may want to use other Fortran90/95 compilers e.g., ifc etc.
• Many ports doesnot honor F77, FC flags, which is not portable.
• Many ports expects libg2c is there, which is not portable.

• FreeBSD 5,6 users must also install gfortran even though g77 is in the base.
• Basically g77 and gfortran42 can co-exist. but we must consider many cases of incompatibility issues. this requires huge maintenance cost.
• gcc42, g++42 are also installed.
• Recompilation required.
• Object incompatibility risk between gcc3.x/gcc41/gcc43 and gfortran42. this requires tremendous maintenance cost in ports.

News

• USE_FORTRAN knob has been tested by gerald@ portmgr@, and I commited(bsd.gcc.mk, bsd.ports.mk, CHANGES). (2007/07/12)
• g95 is not supported as it is based on gcc-4.0 which is too old.

How to migrate to Fortran90/95 or for new ports?

• Please add following like

  USE_FORTRAN=	yes
  

  Othre possiblities are

  USE_FORTRAN=	ifort
  

  USE_FORTRAN=	g77
  

  Ifort implies intel fortran compiler (lang/ifc) and g77 impiles /usr/bin/f77 for FreeBSD>=6 and g77-34 (lang/gcc34) for FreeBSD>=7.
• Looking for runtime routine. (libg2c for g77). Adding following or modifications *AFTER* the patch section. maybe at pre-configure or pre-build section?

  FORTRANLIBS=    -lgfortranbegin -lgfortran
  GCCLIBDIR=     -L`${CAT} ${WRKSRC}/LIBDIR` -L`${CAT} ${WRKSRC}/LIBDIR`/../../..
  post-patch:
  	${DIRNAME} `${F77} -print-libgcc-file-name` > ${WRKSRC}/LIBDIR
  	${REINPLACE_CMD} -e "s+%%GCCLIBDIR%%+${GCCLIBDIR}+" -e "s+%%FORTRANLIBS%%+${FORTRANLIBS}+" ${WRKSRC}/somefile.
  

List of migrated ports that uses gfortran

• If some others has (MAINTAINER or submitter) touched via PR or direct commit, I won't handle this port anymore. Reason line will be `committed'
• If MAINTAINER is set, I won't handle this port anymore. Reason line will be 'maintainer'.
• If pointy hat log is given with successful build for FBSD6/i386, I won't handle this port anymore (if MAINTAINER is not maho) (though, not very strict), Reason line will be 'pointyhat'.
• If maho@ thinks okay, Reason line will be 'maho'. ;)
• If I send a patch for maintainer, Reason line will be 'send a patch'.

List of ports that working in progress

• Waiting for log means waiting for pointhat build log, or report

List of NOT migrated ports that uses Fortran

• Won't migrate means, this port won't migarete with some reasons. e.g., expire soon

List of broken ports

• Currently no broken ports are known so far.

Milestone

• 1. Identify which ports uses Fortran
• 2. migrate to gfortran.
• 3. stabilize them.
• 4. add some flags in /usr/ports/Mk like *_FORTRAN=yes to easy migration (WE ARE HERE)
• 5. Add support for ifc as base(it doesn't mean in the base system) Fortran compiler for higher perfomance or compatibility issues.

QUESTIONS?

Links

• GNU Gfortran
• Intel Fortran Compiler
• Intel Fortran Compiler for FreeBSD (ports)
• G95 project (GFortran is forked from here)
• EKOPath Compiler Suite

Notes

• Note that Elmer-* uses FCFLAGS (F90 compilers flags) and, at least in theory, can also use a specific Fortran Preprocessor (there is one in ports).

Contributors

• FreeBSD ports team