Fix a nasty order of evaluation bug that Gabor Greif ran into. Here's an

explanation from IRC:

	|sabre|	I think it's an order of evaluation thing
	|sabre|	for me, the RHS of the assignment is evaluated first
	|sabre|	getTypeDescription checks to see if ConcreteTypeDescription[Ty] contains anything
	|sabre|	since it doesn't, it computes and returns the value
	|sabre|	this gets put into the map.
	|sabre|	For you, the LHS is evaluated first.
	|sabre|	Map[Ty] (aka ConcreteTypeDescriptions[Ty]) inserts an empty string into the map, returning a reference
	|sabre|	getTypeDesc then sees the empty string in the map
	|sabre|	and returns it
	|sabre|	bork :)

llvm-svn: 20394

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/VMCore/Type.cpp b/llvm/lib/VMCore/Type.cpp
index d2d6a2a9439..875de4b6357 100644
--- a/llvm/lib/VMCore/Type.cpp
+++ b/llvm/lib/VMCore/Type.cpp
@@ -291,7 +291,8 @@ static const std::string &getOrCreateDesc(std::map<const Type*,std::string>&Map,
   if (I != Map.end()) return I->second;
     
   std::vector<const Type *> TypeStack;
-  return Map[Ty] = getTypeDescription(Ty, TypeStack);
+  std::string Result = getTypeDescription(Ty, TypeStack);
+  return Map[Ty] = Result;
 }