-std=c99 defaults blocks to off even on darwin, but -fblocks overrides
even it. 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60568 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/clang.cpp b/Driver/clang.cpp
index 303bfe7..c9022e4 100644
--- a/Driver/clang.cpp
+++ b/Driver/clang.cpp
@@ -569,8 +569,16 @@
   
   // Mimicing gcc's behavior, trigraphs are only enabled if -trigraphs or -ansi
   // is specified, or -std is set to a conforming mode.  
-  Options.Trigraphs = LangStd < lang_gnu_START || Trigraphs ? 1 : 0;
+  Options.Trigraphs = LangStd < lang_gnu_START;
+  if (Trigraphs.getPosition())
+    Options.Trigraphs = Trigraphs;  // Command line option wins.
 
+  // If in a conformant language mode (e.g. -std=c99) Blocks defaults to off
+  // even if they are normally on for the target.  In GNU modes (e.g.
+  // -std=gnu99) the default for blocks depends on the target settings.
+  if (LangStd < lang_gnu_START)
+    Options.Blocks = 0;
+  
   Options.DollarIdents = 1;  // FIXME: Really a target property.
   if (PascalStrings.getPosition())
     Options.PascalStrings = PascalStrings;