20.3 Simplify Porting

Making g77 easier to configure, port, build, and install, either as a single-system compiler or as a cross-compiler, would be very useful.

• A new library (replacing libg2c) should improve portability as well as produce more optimal code. Further, g77 and the new library should conspire to simplify naming of externals, such as by removing unnecessarily added underscores, and to reduce/eliminate the possibility of naming conflicts, while making debugger more straightforward.

  Also, it should make multi-language applications more feasible, such as by providing Fortran intrinsics that get Fortran unit numbers given C FILE * descriptors.

• Possibly related to a new library, g77 should produce the equivalent of a gcc `main(argc, argv)' function when it compiles a main program unit, instead of compiling something that must be called by a library implementation of main().

  This would do many useful things such as provide more flexibility in terms of setting up exception handling, not requiring programmers to start their debugging sessions with breakpoint MAIN__ followed by run, and so on.

• The GBE needs to understand the difference between alignment requirements and desires. For example, on Intel x86 machines, g77 currently imposes overly strict alignment requirements, due to the back end, but it would be useful for Fortran and C programmers to be able to override these recommendations as long as they don't violate the actual processor requirements.