1 files changed, 10 insertions, 6 deletions
diff --git a/emcc b/emcc
index 53a48122..071db703 100755
--- a/emcc
+++ b/emcc
@@ -367,7 +367,7 @@ def is_minus_s_for_emcc(newargs,i):
 CONFIGURE_CONFIG = os.environ.get('EMMAKEN_JUST_CONFIGURE') or 'conftest.c' in sys.argv
 CMAKE_CONFIG = 'CMakeFiles/cmTryCompileExec.dir' in ' '.join(sys.argv)# or 'CMakeCCompilerId' in ' '.join(sys.argv)
 if CONFIGURE_CONFIG or CMAKE_CONFIG:
-  compiler = shared.CLANG
+  compiler = os.environ.get('CONFIGURE_CC') or shared.CLANG # if CONFIGURE_CC is defined, use that. let's you use local gcc etc. if you need that
   if not ('CXXCompiler' in ' '.join(sys.argv) or os.environ.get('EMMAKEN_CXX')):
     compiler = shared.to_cc(compiler)
   def filter_emscripten_options(argv):
@@ -508,11 +508,15 @@ try:
 
   for i in range(len(newargs)):
     if newargs[i].startswith('-O'):
-      try:
-        opt_level = int(newargs[i][2])
-        assert 0 <= opt_level <= 3
-      except:
-        raise Exception('Invalid optimization level: ' + newargs[i])
+      requested_level = newargs[i][2]
+      if requested_level == 's':
+        print >> sys.stderr, 'emcc: warning: -Os is ignored (use -O0, -O1, -O2)'
+      else:
+        try:
+          opt_level = int(requested_level)
+          assert 0 <= opt_level <= 3
+        except:
+          raise Exception('Invalid optimization level: ' + newargs[i])
       newargs[i] = ''
     elif newargs[i].startswith('--llvm-opts'):
       check_bad_eq(newargs[i])