GN Mac build work

tools/gn/command_gyp.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <iostream>
 #include <map>
 #include <utility>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 215 matching lines @@
   // Match up the debug and release version of each target by label.
   CorrelatedTargetsMap correlated;
   CorrelateTargets(debug_targets, release_targets, &correlated);
 
   GypHelper helper;
   GroupedTargetsMap grouped_targets;
   int target_count = 0;
   for (CorrelatedTargetsMap::iterator i = correlated.begin();
        i != correlated.end(); ++i) {
     const TargetGroup& group = i->second;
-    if (!EnsureTargetsMatch(group, err))
-      return std::make_pair(0, 0);
-
     if (!group.debug->item_node()->should_generate())
       continue;  // Skip non-generated ones.
     if (group.debug->external())
       continue;  // Skip external ones.
     if (group.debug->gyp_file().is_null())
       continue;  // Skip ones without GYP files.
 
+    if (!EnsureTargetsMatch(group, err))
+      return std::make_pair(0, 0);
+
     target_count++;
     grouped_targets[helper.GetGypFileForTarget(group.debug, err)].push_back(
         group);
     if (err->has_error())
       return std::make_pair(0, 0);
   }
 
   // Write each GYP file.
   for (GroupedTargetsMap::iterator i = grouped_targets.begin();
        i != grouped_targets.end(); ++i) {
@@ skipping 123 matching lines @@
         + " GN files in " +
         base::IntToString((end_time - begin_time).InMilliseconds()) + "ms\n";
 
     OutputString(stats);
   }
 
   return 0;
 }
 
 }  // namespace commands