Bug 852103 - Fix race condition with .deps directory creation. r=ted

python/codegen/makeutils.py

@@ -2,6 +2,8 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
 
+import errno
+
 dependencies = []
 targets = []
 
@@ -10,6 +12,14 @@ def makeQuote(filename):
 
 def writeMakeDependOutput(filename):
     print "Creating makedepend file", filename
+    dir = os.path.dirname(filename)
+    if dir and not os.path.exists(dir):
+        try:
+            os.makedirs(dir)
+        except OSError as error:
+            if error.errno != errno.EEXIST:
+                raise
+
     with open(filename, 'w') as f:
         if len(targets) > 0:
             f.write("%s:" % makeQuote(targets[0]))