[llvm-commits] CVS: llvm/lib/VMCore/Type.cpp

[Chris Lattner]

Changes in directory llvm/lib/VMCore:

Type.cpp updated: 1.121 -> 1.122
---
Log message:

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 :)


---
Diffs of the changes:  (+2 -1)

 Type.cpp |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)


Index: llvm/lib/VMCore/Type.cpp
diff -u llvm/lib/VMCore/Type.cpp:1.121 llvm/lib/VMCore/Type.cpp:1.122
--- llvm/lib/VMCore/Type.cpp:1.121	Sat Jan  8 14:19:51 2005
+++ llvm/lib/VMCore/Type.cpp	Tue Mar  1 21:54:43 2005
@@ -291,7 +291,8 @@
   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;
 }