Allow transformation of VariableArray to ConstantArray.

In the following code:

    struct A { static const int sz; };
    template<class T> void f() { T arr[A::sz]; }

the array 'arr' is represented as a variable size array in the template.
If 'A::sz' gets value below in the translation unit, the array in
instantiation can turn into constant size array.

This change fixes PR18633.

Differential Revision: http://llvm-reviews.chandlerc.com/D2688

llvm-svn: 200899

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 93cb4833212..7afed1a4480 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -3929,7 +3929,9 @@ TreeTransform<Derived>::TransformVariableArrayType(TypeLocBuilder &TLB,
       return QualType();
   }
 
-  VariableArrayTypeLoc NewTL = TLB.push<VariableArrayTypeLoc>(Result);
+  // We might have constant size array now, but fortunately it has the same
+  // location layout.
+  ArrayTypeLoc NewTL = TLB.push<ArrayTypeLoc>(Result);
   NewTL.setLBracketLoc(TL.getLBracketLoc());
   NewTL.setRBracketLoc(TL.getRBracketLoc());
   NewTL.setSizeExpr(Size);