From a655d04541aa76c6e57e528a2eac13d3fbea768c Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 9 Apr 2019 18:41:02 -0400
Subject: [PATCH] Add Depfile builder mixin - #94

---
 lib/rscons.rb                         |  1 +
 lib/rscons/builders/mixins/depfile.rb | 21 +++++++++++++++++++++
 lib/rscons/builders/mixins/object.rb  |  9 +++------
 lib/rscons/builders/preprocess.rb     |  9 +++------
 4 files changed, 28 insertions(+), 12 deletions(-)
 create mode 100644 lib/rscons/builders/mixins/depfile.rb

diff --git a/lib/rscons.rb b/lib/rscons.rb
index d8927bb..46132d2 100644
--- a/lib/rscons.rb
+++ b/lib/rscons.rb
@@ -166,6 +166,7 @@ module Rscons
 end
 
 # builder mixins
+require_relative "rscons/builders/mixins/depfile"
 require_relative "rscons/builders/mixins/object"
 require_relative "rscons/builders/mixins/object_deps"
 
diff --git a/lib/rscons/builders/mixins/depfile.rb b/lib/rscons/builders/mixins/depfile.rb
new file mode 100644
index 0000000..9b5ce49
--- /dev/null
+++ b/lib/rscons/builders/mixins/depfile.rb
@@ -0,0 +1,21 @@
+module Rscons
+  module Builders
+    module Mixins
+      # Mixin for builders that make use of generated dependency files.
+      module Depfile
+
+        # Finalize a build operation including dependencies from a generated
+        # dependency file.
+        def finalize_command_with_depfile
+          deps = @sources
+          if File.exists?(@vars["_DEPFILE"])
+            deps += Util.parse_makefile_deps(@vars["_DEPFILE"])
+          end
+          @cache.register_build(@target, @command, deps.uniq, @env)
+          true
+        end
+
+      end
+    end
+  end
+end
diff --git a/lib/rscons/builders/mixins/object.rb b/lib/rscons/builders/mixins/object.rb
index b5b3ed4..5ed553b 100644
--- a/lib/rscons/builders/mixins/object.rb
+++ b/lib/rscons/builders/mixins/object.rb
@@ -3,6 +3,8 @@ module Rscons
     module Mixins
       module Object
 
+        include Depfile
+
         class << self
           # Hook called by Ruby when this module is included by a class (klass).
           def included(klass)
@@ -50,12 +52,7 @@ module Rscons
         # Run the builder to produce a build target.
         def run(params)
           if @command
-            deps = @sources
-            if File.exists?(@vars["_DEPFILE"])
-              deps += Util.parse_makefile_deps(@vars["_DEPFILE"])
-            end
-            @cache.register_build(@target, @command, deps.uniq, @env)
-            true
+            finalize_command_with_depfile
           else
             @vars["_TARGET"] = @target
             @vars["_SOURCES"] = @sources
diff --git a/lib/rscons/builders/preprocess.rb b/lib/rscons/builders/preprocess.rb
index 4fa8b5c..5510b95 100644
--- a/lib/rscons/builders/preprocess.rb
+++ b/lib/rscons/builders/preprocess.rb
@@ -5,15 +5,12 @@ module Rscons
     # The Preprocess builder invokes the C preprocessor
     class Preprocess < Builder
 
+      include Mixins::Depfile
+
       # Run the builder to produce a build target.
       def run(options)
         if @command
-          deps = @sources
-          if File.exists?(@vars["_DEPFILE"])
-            deps += Util.parse_makefile_deps(@vars["_DEPFILE"])
-          end
-          @cache.register_build(@target, @command, deps.uniq, @env)
-          true
+          finalize_command_with_depfile
         else
           if @sources.find {|s| s.end_with?(*@env.expand_varref("${CXXSUFFIX}", @vars))}
             pp_cc = "${CXX}"