ExtUtils::MM_Unix contains Perl methods used by ExtUtils::MakeMaker.
The methods provided by this package are designed to be used in conjunction with ExtUtils::MakeMaker. When MakeMaker writes a Makefile, it creates one or more objects that inherit their methods from a package MM. MM itself doesn't provide any methods, but it ISA ExtUtils::MM_Unix class. The inheritance tree of MM lets operating specific packages take the responsibility for all the methods provided by MM_Unix. We are trying to reduce the number of the necessary overrides by defining rather primitive operations within ExtUtils::MM_Unix.
If you are going to write a platform specific MM package, please try to limit the necessary overrides to primitive methods, and if it is not possible to do so, let's work out how to achieve that gain.
If you are overriding any of these methods in your Makefile.PL (in the MY class), please report that to the makemaker mailing list. We are trying to minimize the necessary method overrides and switch to data driven Makefile.PLs wherever possible. In the long run less methods will be overridable via the MY class.
The following description of methods is still under development. Please refer to the code for not suitably documented sections and complain loudly to the firstname.lastname@example.org mailing list. Better yet, provide a patch.
Not all of the methods below are overridable in a Makefile.PL. Overridable methods are marked as (o). All methods are overridable by a platform specific MM_*.pm file.
Cross-platform methods are being moved into MM_Any. If you can't find something that used to be in here, look in MM_Any.