fully parallelize the Disassemble builder

lib/rscons/builders/disassemble.rb

@@ -2,6 +2,7 @@ module Rscons
   module Builders
     # The Disassemble builder produces a disassembly listing of a source file.
     class Disassemble < Builder
+
       # Return default construction variables for the builder.
       #
       # @param env [Environment] The Environment using the builder.
@@ -28,13 +29,28 @@ module Rscons
       def run(target, sources, cache, env, vars)
         vars = vars.merge("_SOURCES" => sources)
         command = env.build_command("${DISASM_CMD}", vars)
-        unless cache.up_to_date?(target, command, sources, env)
-          cache.mkdir_p(File.dirname(target))
-          return false unless env.execute("Disassemble #{target}", command, options: {out: target})
-          cache.register_build(target, command, sources, env)
-        end
+        if cache.up_to_date?(target, command, sources, env)
           target
-      end
+        else
+          cache.mkdir_p(File.dirname(target))
+          ThreadedCommand.new(
+            command,
+            short_description: "Disassemble #{target}",
+            system_options: {out: target})
+        end
+      end
+
+      # Finalize a build.
+      #
+      # @param options [Hash]
+      #   Finalize options.
+      #
+      # @return [String, nil]
+      #   The target name on success or nil on failure.
+      def finalize(options)
+        standard_finalize(options)
+      end
+
     end
   end
 end

spec/build_tests_spec.rb

@@ -439,10 +439,15 @@ EOF
 
   it "supports disassembling object files" do
     test_dir("simple")
+
     result = run_test(rsconsfile: "disassemble.rb")
     expect(result.stderr).to eq ""
     expect(File.exists?("simple.txt")).to be_truthy
     expect(File.read("simple.txt")).to match /Disassembly of section .text:/
+
+    result = run_test(rsconsfile: "disassemble.rb")
+    expect(result.stderr).to eq ""
+    expect(result.stdout).to eq ""
   end
 
   it "supports preprocessing C sources" do

spec/rscons/builders/disassemble_spec.rb

@@ -1,17 +0,0 @@
-module Rscons
-  module Builders
-    describe Disassemble do
-      let(:env) {Environment.new}
-      subject {Disassemble.new}
-
-      it "supports overriding DISASM_CMD construction variable" do
-        cache = "cache"
-        allow(cache).to receive(:up_to_date?) { false }
-        allow(cache).to receive(:mkdir_p) { }
-        allow(cache).to receive(:register_build) { }
-        expect(env).to receive(:execute).with("Disassemble a_file.txt", ["my_disasm", "a_file.exe"], anything).and_return(true)
-        subject.run("a_file.txt", ["a_file.exe"], cache, env, "DISASM_CMD" => ["my_disasm", "${_SOURCES}"])
-      end
-    end
-  end
-end