Cache imported types

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95543 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 1 deletions

diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index dc3281afba..16fd7e6184 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -434,13 +434,21 @@ QualType ASTImporter::Import(QualType FromT) {
   if (FromT.isNull())
     return QualType();
   
-  // FIXME: Cache type mappings?
+  // Check whether we've already imported this type.  
+  llvm::DenseMap<Type *, Type *>::iterator Pos
+    = ImportedTypes.find(FromT.getTypePtr());
+  if (Pos != ImportedTypes.end())
+    return ToContext.getQualifiedType(Pos->second, FromT.getQualifiers());
   
+  // Import the type
   ASTNodeImporter Importer(*this);
   QualType ToT = Importer.Visit(FromT.getTypePtr());
   if (ToT.isNull())
     return ToT;
   
+  // Record the imported type.
+  ImportedTypes[FromT.getTypePtr()] = ToT.getTypePtr();
+  
   return ToContext.getQualifiedType(ToT, FromT.getQualifiers());
 }