Have scons fully evaluate order-only prequisites Nodes before evaluating

a target direct sources and dependencies, so that the actions of the
prerequisites can affect how the sources and dependencies get built
(e.g. building ancillary files for use as input to other steps, without
having to track the direct file dependency).

This tracks an upstream SCons change that will appear in next release:
  http://scons.tigris.org/issues/show_bug.cgi?id=2372
Review URL: http://codereview.chromium.org/43087

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@11461 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 11 insertions, 1 deletions

diff --git a/third_party/scons/scons-local/SCons/Taskmaster.py b/third_party/scons/scons-local/SCons/Taskmaster.py
index 2fffafca2..89f0e36 100644
--- a/third_party/scons/scons-local/SCons/Taskmaster.py
+++ b/third_party/scons/scons-local/SCons/Taskmaster.py
@@ -789,7 +789,17 @@ class Taskmaster:
             children_not_ready = []
             children_failed = False
 
-            for child in chain(children, executor.get_all_prerequisites()):
+            #TODO(sgk)
+            # Evaluate order-only prerequisites before any "direct" children
+            # (sources and dependencies) are evaluated.  This is in advance
+            # of a change that will be incorporated in the next upstream
+            # version of SCons, per:
+            #   http://scons.tigris.org/issues/show_bug.cgi?id=2372
+            #TODO(sgk) - FROM THIS:
+            #for child in chain(children, executor.get_all_prerequisites()):
+            #TODO(sgk) - TO THIS:
+            for child in chain(executor.get_all_prerequisites(), children):
+            #TODO(sgk) - END CHANGES.
                 childstate = child.get_state()
 
                 if T: T.write(self.trace_message('       ' + self.trace_node(child)))