2 files changed, 5 insertions, 1 deletions
diff --git a/emcc b/emcc
index d28df40f..64c65d47 100755
--- a/emcc
+++ b/emcc
@@ -646,7 +646,8 @@ try:
   for i in range(len(newargs)):
     newargs[i] = newargs[i].strip() # On Windows Vista (and possibly others), excessive spaces in the command line leak into the items in this array, so trim e.g. 'foo.cpp ' -> 'foo.cpp'
     if newargs[i].startswith('-O'):
-      requested_level = newargs[i][2]
+      # Let -O default to -O2, which is what gcc does.
+      requested_level = newargs[i][2:] or '2'
       if requested_level == 's':
         print >> sys.stderr, 'emcc: warning: -Os is ignored (use -O0, -O1, -O2)'
       else:
diff --git a/tools/shared.py b/tools/shared.py
index 0282fbb1..7fc2b7c2 100644
--- a/tools/shared.py
+++ b/tools/shared.py
@@ -663,6 +663,9 @@ set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)''' % { 'winfix': '' if not WINDOWS e
   def make(args, stdout=None, stderr=None, env=None):
     if env is None:
       env = Building.get_building_env()
+    if not args:
+      print >> sys.stderr, 'Error: Executable to run not specified.'
+      sys.exit(1)
     #args += ['VERBOSE=1']
     try:
       Popen(args, stdout=stdout, stderr=stderr, env=env).communicate()