Remove the dynamic self replacement from canonicalization

where it doesn't belong and move it directly into
BindGenericTypeParameters, where it is the only desirable
transformation and full canonicalization is actually
counterproductive.

A subsequent patch will enable the TypeRef typesystem in the
expression evaluator. This is a prerequisite for that to work.

Author: adrian-prantl

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.cpp

@@ -324,16 +324,6 @@ GetCanonicalNode(lldb_private::Module *M, swift::Demangle::Demangler &dem,
         return node_clangtype.first;
       return node;
     }
-    case Node::Kind::DynamicSelf: {
-      // Substitute the static type for dynamic self.
-      assert(node->getNumChildren() == 1);
-      if (node->getNumChildren() != 1)
-        return node;
-      NodePointer type = node->getChild(0);
-      if (type->getKind() != Node::Kind::Type || type->getNumChildren() != 1)
-        return node;
-      return type->getChild(0);
-    }
     default:
       break;
     }

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.h

@@ -260,6 +260,7 @@ class TypeSystemSwiftTypeRef : public TypeSystemSwift {
   /// Recursively transform the demangle tree starting a \p node by
   /// doing a post-order traversal and replacing each node with
   /// fn(node).
+  /// The NodePointer passed to \p fn is guaranteed to be non-null.
   static swift::Demangle::NodePointer Transform(
       swift::Demangle::Demangler &dem, swift::Demangle::NodePointer node,
       std::function<swift::Demangle::NodePointer(swift::Demangle::NodePointer)>

lldb/source/Target/SwiftLanguageRuntimeDynamicTypeResolution.cpp

@@ -1325,9 +1325,20 @@ SwiftLanguageRuntimeImpl::BindGenericTypeParameters(StackFrame &stack_frame,
   }
 
   swift::Demangle::Demangler dem;
-  swift::Demangle::NodePointer canonical =
-      TypeSystemSwiftTypeRef::GetCanonicalDemangleTree(
-          ts.GetModule(), dem, mangled_name.GetStringRef());
+  swift::Demangle::NodePointer canonical = TypeSystemSwiftTypeRef::Transform(
+      dem, dem.demangleSymbol(mangled_name.GetStringRef()),
+      [](swift::Demangle::NodePointer node) {
+        if (node->getKind() != Node::Kind::DynamicSelf)
+          return node;
+        // Substitute the static type for dynamic self.
+        assert(node->getNumChildren() == 1);
+        if (node->getNumChildren() != 1)
+          return node;
+        NodePointer type = node->getChild(0);
+        if (type->getKind() != Node::Kind::Type || type->getNumChildren() != 1)
+          return node;
+        return type->getChild(0);
+      });
 
   // Build the list of type substitutions.
   swift::reflection::GenericArgumentMap substitutions;