From: Hugh Sasse Staff Elec Eng <hgs@...>
Date: 2002-02-07T01:11:49+09:00
Subject: mkmf, extconf.rb

Further to my suggestions in Ruby-Talk:31391, about adding methods to
mkmf so that rules can be added to makefiles, I have "lashed together"
the following patch.  It works with an array of dependencies, but before
I test all the combinations of arguments permitted, has anyone any
comments?

	Hugh

--- ./mkmf.rb.orig	Wed Feb  6 14:12:20 2002
+++ ./mkmf.rb	Wed Feb  6 15:57:34 2002
@@ -19,6 +19,10 @@
 $sitelibdir = CONFIG["sitelibdir"]
 $sitearchdir = CONFIG["sitearchdir"]

+# Variable to hold make rules so they can be added at the
+# end of those derived by this script
+$makerules = ""
+
 if File.exist? Config::CONFIG["archdir"] + "/ruby.h"
   $hdrdir = $archdir
 elsif File.exist? $srcdir + "/ruby.h"
@@ -361,6 +365,41 @@
   /^\$[\(\{]/ =~ dir ? dir : "$(DESTDIR)"+dir
 end

+# Write a makefile rule out as a string
+def create_make_rule(target, dependencies, actions)
+    rule = "#{target}:\t"
+    # This uses type dispatch -- strings and arrays both respond_to each
+    case dependencies
+    when String
+        rule << dependencies.chomp
+    when Array
+        dependencies.each { |dep|
+            rule << "#{dep.chomp} "
+        }
+    when nil
+    else
+        raise "$0: create_make_rule: dependencies" \
+            "#{dependencies.inspect} of unknown type"
+    end
+    rule << "\n"
+    # String.each is String.each_line, so this will be
+    # the same as if an array has been passed
+    unless actions.nil?
+        # each will fail if actions is nil.
+        actions.each { |action|
+            rule << "\t#{action.chomp}\n"
+        }
+    end
+    rule << "\n"
+    return rule
+end
+
+# Add a make rule to the Makefile which will be output
+def add_make_rule(target, dependencies, actions)
+    $makerules <<  create_make_rule(target, dependencies, actions)
+end
+
+
 def create_makefile(target, srcdir = File.dirname($0))
   save_libs = $libs.dup
   save_libpath = $LIBPATH.dup
@@ -496,6 +535,10 @@

 site-install:	$(sitearchdir)$(target_prefix)/$(DLLIB)

+### Rules added through add_make_rule()
+EOMF
+  mfile.printf "#{$makerules}\n"
+  mfile.printf <<EOMF
 $(archdir)$(target_prefix)/$(DLLIB): $(DLLIB)
 	@$(RUBY) -r ftools -e 'File::makedirs(*ARGV)' $(rubylibdir) $(archdir)$(target_prefix)
 	@$(RUBY) -r ftools -e 'File::install(ARGV[0], ARGV[1], 0555, true)' $(DLLIB) $(archdir)$(target_prefix)/$(DLLIB)