Rework builder features to be returned by Builder#features instead of taken into account by Builder#produces?

lib/rscons/builders/object.rb

@@ -62,16 +62,18 @@ module Rscons
       # Return whether this builder object is capable of producing a given target
       # file name from a given source file name.
       #
-      # @param options [Hash]
-      #   Options.
+      # @param target [String]
+      #   The target file name.
+      # @param source [String]
+      #   The source file name.
+      # @param env [Environment]
+      #   The Environment.
       #
       # @return [Boolean]
       #   Whether this builder object is capable of producing a given target
       #   file name from a given source file name.
-      def produces?(options)
-        target, source, env, features = options.values_at(:target, :source, :env, :features)
-        (not features[:shared]) and
-          target.end_with?(*env['OBJSUFFIX']) and
+      def produces?(target, source, env)
+        target.end_with?(*env['OBJSUFFIX']) and
           KNOWN_SUFFIXES.find do |compiler, suffix_var|
             source.end_with?(*env[suffix_var])
           end

lib/rscons/builders/shared_library.rb

@@ -21,6 +21,14 @@ module Rscons
         }
       end
 
+      # Return a set of build features that this builder provides.
+      #
+      # @return [Array<String>]
+      #   Set of build features that this builder provides.
+      def features
+        %w[shared]
+      end
+
       # Create a BuildTarget object for this build target.
       #
       # The build target filename is given a platform-dependent suffix if no
@@ -61,7 +69,7 @@ module Rscons
         suffixes = env.expand_varref(["${OBJSUFFIX}", "${LIBSUFFIX}"], vars)
         # Register builders to build each source to an object file or library.
         env.register_builds(target, sources, suffixes, vars,
-                            features: {shared: true})
+                            features: %w[shared])
       end
 
       # Run the builder to produce a build target.

lib/rscons/builders/shared_object.rb

@@ -37,19 +37,29 @@ module Rscons
         }
       end
 
+      # Return a set of build features that this builder provides.
+      #
+      # @return [Array<String>]
+      #   Set of build features that this builder provides.
+      def features
+        %w[shared]
+      end
+
       # Return whether this builder object is capable of producing a given target
       # file name from a given source file name.
       #
-      # @param options [Hash]
-      #   Options.
+      # @param target [String]
+      #   The target file name.
+      # @param source [String]
+      #   The source file name.
+      # @param env [Environment]
+      #   The Environment.
       #
       # @return [Boolean]
       #   Whether this builder object is capable of producing a given target
       #   file name from a given source file name.
-      def produces?(options)
-        target, source, env, features = options.values_at(:target, :source, :env, :features)
-        features[:shared] and
-          target.end_with?(*env['OBJSUFFIX']) and
+      def produces?(target, source, env)
+        target.end_with?(*env['OBJSUFFIX']) and
           KNOWN_SUFFIXES.find do |compiler, suffix_var|
             source.end_with?(*env[suffix_var])
           end