Eliminate redundant deep dependencies

[mohawk2]

EUMM-generated makefiles currently have direct dependencies e.g. from manifypods to module files under lib, which are redundant because manifypods also depends on pure_all, which indirectly depends on those module files. A particular culprit is things depending on $(FIRST_MAKEFILE) directly, rather than via config. This PR eliminates those redundant dependencies.

Here is a run of pure-perl-make --analyse-redundancy (from CPAN Make), on PDL::Stats:

$ pure-perl-make --analyse-redundancy 
Redundant direct dep: Makefile.aperl Makefile
  Recipe Makefile.aperl:0:
	$(NOECHO) $(ECHO) Writing \"$(MAKE_APERL_FILE)\" for this $(MAP_TARGET)
	$(NOECHO) $(PERLRUNINST) \
		Makefile.PL DIR="Basic:Distr:GLM:GSL:Kmeans:TS" \
		MAKEFILE=$(MAKE_APERL_FILE) LINKTYPE=static \
		MAKEAPERL=1 NORECURS=1 CCCDLFLAGS=
    Makefile.aperl pm_to_blib Makefile
      (already seen Makefile.aperl:0)
    Makefile.aperl static Makefile
      (already seen Makefile.aperl:0)
Redundant direct dep: all pure_all
  Recipe all:0:
	$(NOECHO) $(NOOP)
    all manifypods pure_all
      (already seen all:0)
Redundant direct dep: distdir create_distdir
  Recipe distdir:0:
	$(NOECHO) $(NOOP)
    distdir distmeta create_distdir
      (already seen distdir:0)
    distdir distmeta metafile create_distdir
      (already seen distdir:0)
Redundant direct dep: distmeta create_distdir
  Recipe distmeta:0:
	$(NOECHO) cd $(DISTVNAME) && $(ABSPERLRUN) -MExtUtils::Manifest=maniadd -e 'exit unless -e q{META.yml};' \
	  -e 'eval { maniadd({q{META.yml} => q{Module YAML meta-data (added by MakeMaker)}}) }' \
	  -e '    or die "Could not add META.yml to MANIFEST: $${'\''@'\''}"' --
	$(NOECHO) cd $(DISTVNAME) && $(ABSPERLRUN) -MExtUtils::Manifest=maniadd -e 'exit unless -f q{META.json};' \
	  -e 'eval { maniadd({q{META.json} => q{Module JSON meta-data (added by MakeMaker)}}) }' \
	  -e '    or die "Could not add META.json to MANIFEST: $${'\''@'\''}"' --
    distmeta metafile create_distdir
      (already seen distmeta:0)
Redundant direct dep: dynamic Makefile
  Recipe dynamic:0:
	$(NOECHO) $(NOOP)
    dynamic config Makefile
      (already seen dynamic:0)
Redundant direct dep: manifypods Stats.pm
  Recipe manifypods:0:
	$(NOECHO) $(POD2MAN) --section=$(MAN3SECTION) --perm_rw=$(PERM_RW) -u \
	  Stats.pm $(INST_MAN3DIR)/PDL::Stats.$(MAN3EXT) 
    manifypods pure_all pm_to_blib Stats.pm
      (already seen manifypods:0)
Redundant direct dep: manifypods config
  Recipe manifypods:0:
	$(NOECHO) $(POD2MAN) --section=$(MAN3SECTION) --perm_rw=$(PERM_RW) -u \
	  Stats.pm $(INST_MAN3DIR)/PDL::Stats.$(MAN3EXT) 
    manifypods pure_all config
      (already seen manifypods:0)
    manifypods pure_all linkext dynamic config
      (already seen manifypods:0)
Redundant direct dep: pure_all config
  Recipe pure_all:0:
	$(NOECHO) $(NOOP)
	$(NOECHO) $(NOOP)
    pure_all linkext dynamic config
      (already seen pure_all:0)
Redundant direct dep: subdirs-test_dynamic dynamic
  Recipe subdirs-test_dynamic:0:
	$(NOECHO) cd Basic && $(MAKE) test_dynamic $(PASTHRU)
	$(NOECHO) cd Distr && $(MAKE) test_dynamic $(PASTHRU)
	$(NOECHO) cd GLM && $(MAKE) test_dynamic $(PASTHRU)
	$(NOECHO) cd GSL && $(MAKE) test_dynamic $(PASTHRU)
	$(NOECHO) cd Kmeans && $(MAKE) test_dynamic $(PASTHRU)
	$(NOECHO) cd TS && $(MAKE) test_dynamic $(PASTHRU)
    subdirs-test_dynamic pure_all linkext dynamic
      (already seen subdirs-test_dynamic:0)
Redundant direct dep: testdb_dynamic dynamic
  Recipe testdb_dynamic:0:
	PERL_DL_NONLAZY=1 $(FULLPERLRUN) $(TESTDB_SW) "-I$(INST_LIB)" "-I$(INST_ARCHLIB)" $(TEST_FILE)
    testdb_dynamic pure_all linkext dynamic
      (already seen testdb_dynamic:0)
Redundant direct dep: testdb_static static
  Recipe testdb_static:0:
	PERL_DL_NONLAZY=1 "/home/osboxes/PDL-Stats/$(MAP_TARGET)" $(MAP_PERLINC) "-I$(INST_LIB)" "-I$(INST_ARCHLIB)" $(TEST_FILE)
    testdb_static perl Makefile.aperl static
      (already seen testdb_static:0)

The makefile for Graph is visualised here, using tkgvizmakefile (not PDL::Stats which is too big as it has 5 subdirs, and the tool pulls in all the recursive makefiles):

The bottom left shows distdir depending on create_distdir both directly (and redundantly), but also via distmeta.

[haarg]

Why is it a problem to have these dependencies? If the manifypods target uses the files directly, it seems appropriate to have direct dependencies on the files.

[mohawk2]

That's an excellent point (and possibly showing I chose the example poorly)! However, that highlights to me that manifypods should actually depend on the .pm files, not on pure_all?

[Leont]

However, that highlights to me that manifypods should actually depend on the .pm files, not on pure_all?

That would have made more sense, but odds are something somewhere is depending on this because it overrides pure_all specifically and not adding .pm entries.