Make ASTDemamgler.cpp independent from ClangImporter.

include/swift/AST/ClangModuleLoader.h

@@ -71,6 +71,33 @@ class ClangModuleLoader : public ModuleLoader {
   virtual bool
   isInOverlayModuleForImportedModule(const DeclContext *overlayDC,
                                      const DeclContext *importedDC) = 0;
+
+  /// Look for declarations associated with the given name.
+  ///
+  /// \param name The name we're searching for.
+  virtual void lookupValue(DeclName name, VisibleDeclConsumer &consumer) = 0;
+
+  /// Look up a type declaration by its Clang name.
+  ///
+  /// Note that this method does no filtering. If it finds the type in a loaded
+  /// module, it returns it. This is intended for use in reflection / debugging
+  /// contexts where access is not a problem.
+  virtual void
+  lookupTypeDecl(StringRef clangName, ClangTypeKind kind,
+                 llvm::function_ref<void(TypeDecl *)> receiver) = 0;
+
+  /// Look up type a declaration synthesized by the Clang importer itself, using
+  /// a "related entity kind" to determine which type it should be. For example,
+  /// this can be used to find the synthesized error struct for an
+  /// NS_ERROR_ENUM.
+  ///
+  /// Note that this method does no filtering. If it finds the type in a loaded
+  /// module, it returns it. This is intended for use in reflection / debugging
+  /// contexts where access is not a problem.
+  virtual void
+  lookupRelatedEntity(StringRef clangName, ClangTypeKind kind,
+                      StringRef relatedEntityKind,
+                      llvm::function_ref<void(TypeDecl *)> receiver) = 0;
 };
 
 } // namespace swift

include/swift/ClangImporter/ClangImporter.h

@@ -172,15 +172,15 @@ class ClangImporter final : public ClangModuleLoader {
   /// Look for declarations associated with the given name.
   ///
   /// \param name The name we're searching for.
-  void lookupValue(DeclName name, VisibleDeclConsumer &consumer);
+  void lookupValue(DeclName name, VisibleDeclConsumer &consumer) override;
 
   /// Look up a type declaration by its Clang name.
   ///
   /// Note that this method does no filtering. If it finds the type in a loaded
   /// module, it returns it. This is intended for use in reflection / debugging
   /// contexts where access is not a problem.
   void lookupTypeDecl(StringRef clangName, ClangTypeKind kind,
-                      llvm::function_ref<void(TypeDecl *)> receiver);
+                      llvm::function_ref<void(TypeDecl *)> receiver) override;
 
   /// Look up type a declaration synthesized by the Clang importer itself, using
   /// a "related entity kind" to determine which type it should be. For example,
@@ -193,7 +193,7 @@ class ClangImporter final : public ClangModuleLoader {
   void
   lookupRelatedEntity(StringRef clangName, ClangTypeKind kind,
                       StringRef relatedEntityKind,
-                      llvm::function_ref<void(TypeDecl *)> receiver);
+                      llvm::function_ref<void(TypeDecl *)> receiver) override;
 
   /// Look for textually included declarations from the bridging header.
   ///

lib/AST/ASTDemangler.cpp

@@ -22,14 +22,14 @@
 #include "swift/AST/ASTDemangler.h"
 
 #include "swift/AST/ASTContext.h"
+#include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/GenericSignatureBuilder.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/NameLookup.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/Types.h"
-#include "swift/ClangImporter/ClangImporter.h"
 #include "swift/Demangling/Demangler.h"
 #include "swift/Demangling/ManglingMacros.h"
 #include "llvm/ADT/StringSwitch.h"
@@ -1069,7 +1069,7 @@ GenericTypeDecl *ASTBuilder::findForeignTypeDecl(StringRef name,
                                                  ForeignModuleKind foreignKind,
                                                  Demangle::Node::Kind kind) {
   // Check to see if we have an importer loaded.
-  auto importer = static_cast<ClangImporter *>(Ctx.getClangModuleLoader());
+  auto importer = Ctx.getClangModuleLoader();
   if (!importer)
     return nullptr;