Add an option to prune unwanted targets

pylib/gyp/input.py

Index: pylib/gyp/input.py
diff --git a/pylib/gyp/input.py b/pylib/gyp/input.py
index 8abfa3d999e3ed71dae961824292fcd702787058..71535294e989bfa265eaba9767e0faeb350628ca 100644
--- a/pylib/gyp/input.py
+++ b/pylib/gyp/input.py
@@ -2562,6 +2562,22 @@ def TurnIntIntoStrInList(the_list):
       TurnIntIntoStrInList(item)
 
 
+def PruneUnwantedTargets(targets, flat_list, dependency_nodes, build_files):
+  """
+  Return only the targets that are deep dependencies of the targets specified
+  in |build_files|.
+  """
+  wanted_targets = {}
+  for target in flat_list:
+    if gyp.common.BuildFile(target) in build_files:
+      wanted_targets[target] = targets[target]
+      for dependency in dependency_nodes[target].DeepDependencies():
+        wanted_targets[dependency] = targets[dependency]
+
+  wanted_flat_list = [t for t in flat_list if t in wanted_targets]
+  return [wanted_targets, wanted_flat_list]
+
+
 def VerifyNoCollidingTargets(targets):
   """Verify that no two targets in the same directory share the same name.
 
@@ -2590,7 +2606,7 @@ def VerifyNoCollidingTargets(targets):
 
 
 def Load(build_files, variables, includes, depth, generator_input_info, check,
-         circular_check, parallel):
+         circular_check, parallel, prune_targets):
   # Set up path_sections and non_configuration_keys with the default data plus
   # the generator-specifc data.
   global path_sections
@@ -2617,6 +2633,10 @@ def Load(build_files, variables, includes, depth, generator_input_info, check,
   # for rules.
   extra_sources_for_rules = generator_input_info['extra_sources_for_rules']
 
+  # Normalize paths everywhere.  This is important because paths will be

[scottmg, 2013/09/26 22:11:07]

Why did this need to move?

+  # used as keys to the data dict and for references between input files.
+  build_files = [os.path.normpath(i) for i in build_files]
+
   # Load build files.  This loads every target-containing build file into
   # the |data| dictionary such that the keys to |data| are build file names,
   # and the values are the entire build file contents after "early" or "pre"
@@ -2627,9 +2647,6 @@ def Load(build_files, variables, includes, depth, generator_input_info, check,
   data = {'target_build_files': set()}
   aux_data = {}
   for build_file in build_files:
-    # Normalize paths everywhere.  This is important because paths will be
-    # used as keys to the data dict and for references between input files.
-    build_file = os.path.normpath(build_file)
     try:
       if parallel:
         LoadTargetBuildFileParallel(build_file, data, aux_data,
@@ -2678,6 +2695,12 @@ def Load(build_files, variables, includes, depth, generator_input_info, check,
 
   [dependency_nodes, flat_list] = BuildDependencyList(targets)
 
+  if prune_targets:
+    # Remove, from |targets| and |flat_list|, the targets that are not deep
+    # dependencies of the targets specified in |build_files|.
+    [targets, flat_list] = PruneUnwantedTargets(

[scottmg, 2013/09/26 22:11:07]

[ ] around targets, flat_list is odd here. Just return a tuple from the
function.

+        targets, flat_list, dependency_nodes, build_files)
+
   # Check that no two targets in the same directory have the same name.
   VerifyNoCollidingTargets(flat_list)