pass extra construction variables to Builder#run()

build_tests/custom_builder/build.rb

@@ -1,5 +1,5 @@
 class MySource < Rscons::Builder
-  def run(target, sources, cache, env)
+  def run(target, sources, cache, env, vars = {})
     File.open(target, 'w') do |fh|
       fh.puts <<EOF
 #define THE_VALUE 5678

lib/rscons/builders/object.rb

@@ -38,12 +38,12 @@ module Rscons
         source.has_suffix?(env['CXXSUFFIX']))
     end
 
-    def run(target, sources, cache, env)
-      vars = {
+    def run(target, sources, cache, env, vars = {})
+      vars = vars.merge({
         'TARGET' => target,
         'SOURCES' => sources,
         'DEPFILE' => target.set_suffix('.mf'),
-      }
+      })
       com_prefix = if sources.first.has_suffix?(env['ASSUFFIX'])
                      'AS'
                    elsif sources.first.has_suffix?(env['CSUFFIX'])

lib/rscons/builders/program.rb

@@ -14,19 +14,19 @@ module Rscons
       }
     end
 
-    def run(target, sources, cache, env)
+    def run(target, sources, cache, env, vars = {})
       # build sources to linkable objects
-      objects = env.build_sources(sources, [env['OBJSUFFIX'], env['LIBSUFFIX']].flatten, cache)
+      objects = env.build_sources(sources, [env['OBJSUFFIX'], env['LIBSUFFIX']].flatten, cache, vars)
       if objects
         use_cxx = sources.map do |s|
           s.has_suffix?(env['CXXSUFFIX'])
         end.any?
         ld_alt = use_cxx ? env['CXX'] : env['CC']
-        vars = {
+        vars = vars.merge({
           'TARGET' => target,
           'SOURCES' => objects,
           'LD' => env['LD'] || ld_alt,
-        }
+        })
         command = env.build_command(env['LDCOM'], vars)
         unless cache.up_to_date?(target, command, objects)
           return false unless env.execute("LD #{target}", command)

lib/rscons/environment.rb

@@ -141,7 +141,7 @@ module Rscons
                                          @targets[target][:source],
                                          cache,
                                          self,
-                                         *@targets[target][:args])
+                                         @targets[target][:vars] || {})
         else
           false
         end
@@ -193,11 +193,12 @@ module Rscons
     alias_method :orig_method_missing, :method_missing
     def method_missing(method, *args)
       if @builders.has_key?(method.to_s)
-        target, source, *rest = args
+        target, source, vars, *rest = args
         source = [source] unless source.is_a?(Array)
         @targets[target] = {
           builder: @builders[method.to_s],
           source: source,
+          vars: vars,
           args: rest,
         }
       else
@@ -236,7 +237,7 @@ module Rscons
     # @param suffixes [Array] List of suffixes to try to convert source files into.
     # @param cache [Cache] The Cache.
     # Return a list of the converted file names.
-    def build_sources(sources, suffixes, cache)
+    def build_sources(sources, suffixes, cache, vars = {})
       sources.map do |source|
         if source.has_suffix?(suffixes)
           source
@@ -246,7 +247,7 @@ module Rscons
             converted_fname = get_build_fname(source, suffix)
             builder = @builders.values.find { |b| b.produces?(converted_fname, source, self) }
             if builder
-              converted = builder.run(converted_fname, [source], cache, self)
+              converted = builder.run(converted_fname, [source], cache, self, vars)
               return nil unless converted
               break
             end

lib/rscons/varset.rb

@@ -8,7 +8,11 @@ module Rscons
     # Create a VarSet
     # @param vars [Hash] Optional initial variables.
     def initialize(vars = {})
-      @vars = vars
+      if vars.is_a?(VarSet)
+        @vars = vars.clone.vars
+      else
+        @vars = vars
+      end
     end
 
     # Access the value of variable as a particular type