Canonicalization of dependent C++0x decltype types.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77643 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 81cab92..f47e28b 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -1954,9 +1954,26 @@
/// on canonical type's (which are always unique).
QualType ASTContext::getDecltypeType(Expr *e) {
DecltypeType *dt;
- if (e->isTypeDependent()) // FIXME: canonicalize the expression
- dt = new (*this, 8) DecltypeType(e, DependentTy);
- else {
+ if (e->isTypeDependent()) {
+ llvm::FoldingSetNodeID ID;
+ DependentDecltypeType::Profile(ID, *this, e);
+
+ void *InsertPos = 0;
+ DependentDecltypeType *Canon
+ = DependentDecltypeTypes.FindNodeOrInsertPos(ID, InsertPos);
+ if (Canon) {
+ // We already have a "canonical" version of an equivalent, dependent
+ // decltype type. Use that as our canonical type.
+ dt = new (*this, 8) DecltypeType(e, DependentTy,
+ QualType((DecltypeType*)Canon, 0));
+ }
+ else {
+ // Build a new, canonical typeof(expr) type.
+ Canon = new (*this, 8) DependentDecltypeType(*this, e);
+ DependentDecltypeTypes.InsertNode(Canon, InsertPos);
+ dt = Canon;
+ }
+ } else {
QualType T = getDecltypeForExpr(e, *this);
dt = new (*this, 8) DecltypeType(e, T, getCanonicalType(T));
}