[Runtime] Improve dump() for Metadata and (Type)ContextDescriptor

No functionality change.

Author: jrose-apple

include/swift/ABI/Metadata.h

@@ -2485,6 +2485,12 @@ struct TargetContextDescriptor {
               ? genericContext->getGenericContextHeader().NumParams
               : 0;
   }
+
+#ifndef NDEBUG
+  LLVM_ATTRIBUTE_DEPRECATED(void dump() const,
+                            "only for use in the debugger");
+#endif
+
 private:
   TargetContextDescriptor(const TargetContextDescriptor &) = delete;
   TargetContextDescriptor(TargetContextDescriptor &&) = delete;
@@ -3649,11 +3655,6 @@ class TargetTypeContextDescriptor
     return cd->getKind() >= ContextDescriptorKind::Type_First
         && cd->getKind() <= ContextDescriptorKind::Type_Last;
   }
-
-#ifndef NDEBUG
-  LLVM_ATTRIBUTE_DEPRECATED(void dump() const,
-                            "Only meant for use in the debugger");
-#endif
 };
 
 using TypeContextDescriptor = TargetTypeContextDescriptor<InProcess>;

stdlib/public/runtime/Metadata.cpp

@@ -3945,20 +3945,33 @@ void Metadata::dump() const {
   printf("TargetMetadata.\n");
   printf("Kind: %s.\n", getStringForMetadataKind(getKind()).data());
   printf("Value Witnesses: %p.\n", getValueWitnesses());
-  printf("Class Object: %p.\n", getClassObject());
-  printf("Type Context Description: %p.\n", getTypeContextDescriptor());
+
+  auto *contextDescriptor = getTypeContextDescriptor();
+  printf("Name: %s.\n", contextDescriptor->Name.get());
+  printf("Type Context Description: %p.\n", contextDescriptor);
   printf("Generic Args: %p.\n", getGenericArgs());
+
+#if SWIFT_OBJC_INTEROP
+  if (auto *classObject = getClassObject()) {
+    printf("ObjC Name: %s.\n", class_getName(
+        reinterpret_cast<Class>(const_cast<ClassMetadata *>(classObject))));
+    printf("Class Object: %p.\n", classObject);
+  }
+#endif
 }
 
 template <>
 LLVM_ATTRIBUTE_USED
-void TypeContextDescriptor::dump() const {
+void ContextDescriptor::dump() const {
   printf("TargetTypeContextDescriptor.\n");
   printf("Flags: 0x%x.\n", this->Flags.getIntValue());
   printf("Parent: %p.\n", this->Parent.get());
-  printf("Name: %s.\n", Name.get());
-  printf("Access function: %p.\n", static_cast<void *>(getAccessFunction()));
-  printf("Fields: %p.\n", Fields.get());
+  if (auto *typeDescriptor = dyn_cast<TypeContextDescriptor>(this)) {
+    printf("Name: %s.\n", typeDescriptor->Name.get());
+    printf("Fields: %p.\n", typeDescriptor->Fields.get());
+    printf("Access function: %p.\n",
+           static_cast<void *>(typeDescriptor->getAccessFunction()));
+  }
 }
 
 template<>