mkmf.rb: timestamp directory

* lib/mkmf.rb (timestamp_file): gather timestamp files in one
  directory from each extension directories.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40194 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/mkmf.rb

@@ -1922,7 +1922,7 @@ def configuration(srcdir)
 
   def timestamp_file(name)
     name = name.gsub(/(\$[({]|[})])|(\/+)|[^-.\w]+/) {$1 ? "" : $2 ? ".-." : "_"}
-    "./.#{name}.time"
+    "$(TIMESTAMP_DIR)/.#{name}.time"
   end
   # :startdoc:
 
@@ -2174,6 +2174,7 @@ def create_makefile(target, srcprefix = nil)
 EXTSTATIC = #{$static || ""}
 STATIC_LIB = #{staticlib unless $static.nil?}
 #{!$extout && defined?($installed_list) ? "INSTALLED_LIST = #{$installed_list}\n" : ""}
+TIMESTAMP_DIR = #{$extout ? '$(extout)/.timestamp' : '.'}
 " #"
     # TODO: fixme
     install_dirs.each {|d| mfile.print("%-14s= %s\n" % d) if /^[[:upper:]]/ =~ d[0]}
@@ -2267,7 +2268,7 @@ def create_makefile(target, srcprefix = nil)
     dirs.unshift(sodir) if target and !dirs.include?(sodir)
     dirs.each do |d|
       t = timestamp_file(d)
-      mfile.print "#{t}:\n\t$(Q) $(MAKEDIRS) #{d}\n\t$(Q) $(TOUCH) $@\n"
+      mfile.print "#{t}:\n\t$(Q) $(MAKEDIRS) $(@D) #{d}\n\t$(Q) $(TOUCH) $@\n"
     end
 
     mfile.print <<-SITEINSTALL