Override release date in Makefile if possible

Author: nobu

defs/gmake.mk

@@ -56,6 +56,13 @@ ifeq ($(if $(filter all main exts enc trans libencs libenc libtrans \
 -include $(SHOWFLAGS)
 endif
 
+ifeq ($(HAVE_BASERUBY):$(HAVE_GIT),yes:yes)
+override modified := $(shell $(BASERUBY) -C $(srcdir) tool/file2lastrev.rb --modified='%Y %m %d')
+override RUBY_RELEASE_YEAR := $(word 1,$(modified))
+override RUBY_RELEASE_MONTH := $(word 2,$(modified))
+override RUBY_RELEASE_DAY := $(word 3,$(modified))
+endif
+
 ifneq ($(filter universal-%,$(arch)),)
 define archcmd
 %.$(1).S: %.c