GC plugin: split out reporting of errors/warnings.

tools/clang/blink_gc_plugin/DiagnosticsReporter.cpp

Index: tools/clang/blink_gc_plugin/DiagnosticsReporter.cpp
diff --git a/tools/clang/blink_gc_plugin/DiagnosticsReporter.cpp b/tools/clang/blink_gc_plugin/DiagnosticsReporter.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0057d80da58cbb89efa25c85720c82f5ebce6ec3
--- /dev/null
+++ b/tools/clang/blink_gc_plugin/DiagnosticsReporter.cpp
@@ -0,0 +1,527 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "DiagnosticsReporter.h"
+
+using namespace clang;
+
+namespace {
+
+const char kClassMustLeftMostlyDeriveGC[] =
+    "[blink-gc] Class %0 must derive its GC base in the left-most position.";
+
+const char kClassRequiresTraceMethod[] =
+    "[blink-gc] Class %0 requires a trace method.";
+
+const char kBaseRequiresTracing[] =
+    "[blink-gc] Base class %0 of derived class %1 requires tracing.";
+
+const char kBaseRequiresTracingNote[] =
+    "[blink-gc] Untraced base class %0 declared here:";
+
+const char kFieldsRequireTracing[] =
+    "[blink-gc] Class %0 has untraced fields that require tracing.";
+
+const char kFieldRequiresTracingNote[] =
+    "[blink-gc] Untraced field %0 declared here:";
+
+const char kClassContainsInvalidFields[] =
+    "[blink-gc] Class %0 contains invalid fields.";
+
+const char kClassContainsGCRoot[] =
+    "[blink-gc] Class %0 contains GC root in field %1.";
+
+const char kClassRequiresFinalization[] =
+    "[blink-gc] Class %0 requires finalization.";
+
+const char kClassDoesNotRequireFinalization[] =
+    "[blink-gc] Class %0 may not require finalization.";
+
+const char kFinalizerAccessesFinalizedField[] =
+    "[blink-gc] Finalizer %0 accesses potentially finalized field %1.";
+
+const char kFinalizerAccessesEagerlyFinalizedField[] =
+    "[blink-gc] Finalizer %0 accesses eagerly finalized field %1.";
+
+const char kRawPtrToGCManagedClassNote[] =
+    "[blink-gc] Raw pointer field %0 to a GC managed class declared here:";
+
+const char kRefPtrToGCManagedClassNote[] =
+    "[blink-gc] RefPtr field %0 to a GC managed class declared here:";
+
+const char kReferencePtrToGCManagedClassNote[] =
+    "[blink-gc] Reference pointer field %0 to a GC managed class"
+    " declared here:";
+
+const char kOwnPtrToGCManagedClassNote[] =
+    "[blink-gc] OwnPtr field %0 to a GC managed class declared here:";
+
+const char kMemberToGCUnmanagedClassNote[] =
+    "[blink-gc] Member field %0 to non-GC managed class declared here:";
+
+const char kStackAllocatedFieldNote[] =
+    "[blink-gc] Stack-allocated field %0 declared here:";
+
+const char kMemberInUnmanagedClassNote[] =
+    "[blink-gc] Member field %0 in unmanaged class declared here:";
+
+const char kPartObjectToGCDerivedClassNote[] =
+    "[blink-gc] Part-object field %0 to a GC derived class declared here:";
+
+const char kPartObjectContainsGCRootNote[] =
+    "[blink-gc] Field %0 with embedded GC root in %1 declared here:";
+
+const char kFieldContainsGCRootNote[] =
+    "[blink-gc] Field %0 defining a GC root declared here:";
+
+const char kOverriddenNonVirtualTrace[] =
+    "[blink-gc] Class %0 overrides non-virtual trace of base class %1.";
+
+const char kOverriddenNonVirtualTraceNote[] =
+    "[blink-gc] Non-virtual trace method declared here:";
+
+const char kMissingTraceDispatchMethod[] =
+    "[blink-gc] Class %0 is missing manual trace dispatch.";
+
+const char kMissingFinalizeDispatchMethod[] =
+    "[blink-gc] Class %0 is missing manual finalize dispatch.";
+
+const char kVirtualAndManualDispatch[] =
+    "[blink-gc] Class %0 contains or inherits virtual methods"
+    " but implements manual dispatching.";
+
+const char kMissingTraceDispatch[] =
+    "[blink-gc] Missing dispatch to class %0 in manual trace dispatch.";
+
+const char kMissingFinalizeDispatch[] =
+    "[blink-gc] Missing dispatch to class %0 in manual finalize dispatch.";
+
+const char kFinalizedFieldNote[] =
+    "[blink-gc] Potentially finalized field %0 declared here:";
+
+const char kEagerlyFinalizedFieldNote[] =
+    "[blink-gc] Field %0 having eagerly finalized value, declared here:";
+
+const char kUserDeclaredDestructorNote[] =
+    "[blink-gc] User-declared destructor declared here:";
+
+const char kUserDeclaredFinalizerNote[] =
+    "[blink-gc] User-declared finalizer declared here:";
+
+const char kBaseRequiresFinalizationNote[] =
+    "[blink-gc] Base class %0 requiring finalization declared here:";
+
+const char kFieldRequiresFinalizationNote[] =
+    "[blink-gc] Field %0 requiring finalization declared here:";
+
+const char kManualDispatchMethodNote[] =
+    "[blink-gc] Manual dispatch %0 declared here:";
+
+const char kDerivesNonStackAllocated[] =
+    "[blink-gc] Stack-allocated class %0 derives class %1"
+    " which is not stack allocated.";
+
+const char kClassOverridesNew[] =
+    "[blink-gc] Garbage collected class %0"
+    " is not permitted to override its new operator.";
+
+const char kClassDeclaresPureVirtualTrace[] =
+    "[blink-gc] Garbage collected class %0"
+    " is not permitted to declare a pure-virtual trace method.";
+
+const char kLeftMostBaseMustBePolymorphic[] =
+    "[blink-gc] Left-most base class %0 of derived class %1"
+    " must be polymorphic.";
+
+const char kBaseClassMustDeclareVirtualTrace[] =
+    "[blink-gc] Left-most base class %0 of derived class %1"
+    " must define a virtual trace method.";
+
+} // namespace
+
+DiagnosticBuilder DiagnosticsReporter::ReportDiagnostic(
+    SourceLocation location,
+    unsigned diag_id) {
+  SourceManager& manager = instance_.getSourceManager();
+  FullSourceLoc full_loc(location, manager);
+  return diagnostic_.Report(full_loc, diag_id);
+}
+
+DiagnosticsReporter::DiagnosticsReporter(
+    clang::CompilerInstance& instance)
+    : instance_(instance),
+      diagnostic_(instance.getDiagnostics())
+{
+  // Register warning/error messages.
+  diag_class_must_left_mostly_derive_gc_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kClassMustLeftMostlyDeriveGC);
+  diag_class_requires_trace_method_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kClassRequiresTraceMethod);
+  diag_base_requires_tracing_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kBaseRequiresTracing);
+  diag_fields_require_tracing_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kFieldsRequireTracing);
+  diag_class_contains_invalid_fields_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kClassContainsInvalidFields);
+  diag_class_contains_gc_root_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kClassContainsGCRoot);
+  diag_class_requires_finalization_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kClassRequiresFinalization);
+  diag_class_does_not_require_finalization_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Warning, kClassDoesNotRequireFinalization);
+  diag_finalizer_accesses_finalized_field_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kFinalizerAccessesFinalizedField);
+  diag_finalizer_eagerly_finalized_field_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kFinalizerAccessesEagerlyFinalizedField);
+  diag_overridden_non_virtual_trace_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kOverriddenNonVirtualTrace);
+  diag_missing_trace_dispatch_method_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kMissingTraceDispatchMethod);
+  diag_missing_finalize_dispatch_method_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kMissingFinalizeDispatchMethod);
+  diag_virtual_and_manual_dispatch_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kVirtualAndManualDispatch);
+  diag_missing_trace_dispatch_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kMissingTraceDispatch);
+  diag_missing_finalize_dispatch_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kMissingFinalizeDispatch);
+  diag_derives_non_stack_allocated_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kDerivesNonStackAllocated);
+  diag_class_overrides_new_ =
+      diagnostic_.getCustomDiagID(getErrorLevel(), kClassOverridesNew);
+  diag_class_declares_pure_virtual_trace_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kClassDeclaresPureVirtualTrace);
+  diag_left_most_base_must_be_polymorphic_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kLeftMostBaseMustBePolymorphic);
+  diag_base_class_must_declare_virtual_trace_ = diagnostic_.getCustomDiagID(
+      getErrorLevel(), kBaseClassMustDeclareVirtualTrace);
+
+  // Register note messages.
+  diag_base_requires_tracing_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kBaseRequiresTracingNote);
+  diag_field_requires_tracing_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kFieldRequiresTracingNote);
+  diag_raw_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kRawPtrToGCManagedClassNote);
+  diag_ref_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kRefPtrToGCManagedClassNote);
+  diag_reference_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kReferencePtrToGCManagedClassNote);
+  diag_own_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kOwnPtrToGCManagedClassNote);
+  diag_member_to_gc_unmanaged_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kMemberToGCUnmanagedClassNote);
+  diag_stack_allocated_field_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kStackAllocatedFieldNote);
+  diag_member_in_unmanaged_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kMemberInUnmanagedClassNote);
+  diag_part_object_to_gc_derived_class_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kPartObjectToGCDerivedClassNote);
+  diag_part_object_contains_gc_root_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kPartObjectContainsGCRootNote);
+  diag_field_contains_gc_root_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kFieldContainsGCRootNote);
+  diag_finalized_field_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kFinalizedFieldNote);
+  diag_eagerly_finalized_field_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kEagerlyFinalizedFieldNote);
+  diag_user_declared_destructor_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kUserDeclaredDestructorNote);
+  diag_user_declared_finalizer_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kUserDeclaredFinalizerNote);
+  diag_base_requires_finalization_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kBaseRequiresFinalizationNote);
+  diag_field_requires_finalization_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kFieldRequiresFinalizationNote);
+  diag_overridden_non_virtual_trace_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kOverriddenNonVirtualTraceNote);
+  diag_manual_dispatch_method_note_ = diagnostic_.getCustomDiagID(
+      DiagnosticsEngine::Note, kManualDispatchMethodNote);
+}
+
+bool DiagnosticsReporter::hasErrorOccurred() const
+{
+  return diagnostic_.hasErrorOccurred();
+}
+
+DiagnosticsEngine::Level DiagnosticsReporter::getErrorLevel() const {
+  return diagnostic_.getWarningsAsErrors() ? DiagnosticsEngine::Error
+                                           : DiagnosticsEngine::Warning;
+}
+
+void DiagnosticsReporter::ClassMustLeftMostlyDeriveGC(
+    RecordInfo* info) {
+  ReportDiagnostic(info->record()->getInnerLocStart(),
+                   diag_class_must_left_mostly_derive_gc_)
+      << info->record();
+}
+
+void DiagnosticsReporter::ClassRequiresTraceMethod(RecordInfo* info) {
+  ReportDiagnostic(info->record()->getInnerLocStart(),
+                   diag_class_requires_trace_method_)
+      << info->record();
+
+  for (auto& base : info->GetBases())
+    if (base.second.NeedsTracing().IsNeeded())
+      NoteBaseRequiresTracing(&base.second);
+
+  for (auto& field : info->GetFields())
+    if (!field.second.IsProperlyTraced())
+      NoteFieldRequiresTracing(info, field.first);
+}
+
+void DiagnosticsReporter::BaseRequiresTracing(
+    RecordInfo* derived,
+    CXXMethodDecl* trace,
+    CXXRecordDecl* base) {
+  ReportDiagnostic(trace->getLocStart(), diag_base_requires_tracing_)
+      << base << derived->record();
+}
+
+void DiagnosticsReporter::FieldsRequireTracing(
+    RecordInfo* info,
+    CXXMethodDecl* trace) {
+  ReportDiagnostic(trace->getLocStart(), diag_fields_require_tracing_)
+      << info->record();
+  for (auto& field : info->GetFields())
+    if (!field.second.IsProperlyTraced())
+      NoteFieldRequiresTracing(info, field.first);
+}
+
+void DiagnosticsReporter::ClassContainsInvalidFields(
+    RecordInfo* info,
+    const CheckFieldsVisitor::Errors& errors) {
+
+  ReportDiagnostic(info->record()->getLocStart(),
+                   diag_class_contains_invalid_fields_)
+      << info->record();
+
+  for (auto& error : errors) {
+    unsigned note;
+    if (error.second == CheckFieldsVisitor::kRawPtrToGCManaged) {
+      note = diag_raw_ptr_to_gc_managed_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kRefPtrToGCManaged) {
+      note = diag_ref_ptr_to_gc_managed_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kReferencePtrToGCManaged) {
+      note = diag_reference_ptr_to_gc_managed_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kOwnPtrToGCManaged) {
+      note = diag_own_ptr_to_gc_managed_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kMemberToGCUnmanaged) {
+      note = diag_member_to_gc_unmanaged_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kMemberInUnmanaged) {
+      note = diag_member_in_unmanaged_class_note_;
+    } else if (error.second == CheckFieldsVisitor::kPtrFromHeapToStack) {
+      note = diag_stack_allocated_field_note_;
+    } else if (error.second == CheckFieldsVisitor::kGCDerivedPartObject) {
+      note = diag_part_object_to_gc_derived_class_note_;
+    } else {
+      assert(false && "Unknown field error");
+    }
+    NoteField(error.first, note);
+  }
+}
+
+void DiagnosticsReporter::ClassContainsGCRoots(
+    RecordInfo* info,
+    const CheckGCRootsVisitor::Errors& errors) {
+  for (auto& error : errors) {
+    FieldPoint* point = nullptr;
+    for (FieldPoint* path : error) {
+      if (!point) {
+        point = path;
+        ReportDiagnostic(info->record()->getLocStart(),
+                         diag_class_contains_gc_root_)
+            << info->record() << point->field();
+        continue;
+      }
+      NotePartObjectContainsGCRoot(point);
+      point = path;
+    }
+    NoteFieldContainsGCRoot(point);
+  }
+}
+
+void DiagnosticsReporter::FinalizerAccessesFinalizedFields(
+    CXXMethodDecl* dtor,
+    const CheckFinalizerVisitor::Errors& errors) {
+  for (auto& error : errors) {
+    bool as_eagerly_finalized = error.as_eagerly_finalized;
+    unsigned diag_error = as_eagerly_finalized ?
+                          diag_finalizer_eagerly_finalized_field_ :
+                          diag_finalizer_accesses_finalized_field_;
+    unsigned diag_note = as_eagerly_finalized ?
+                         diag_eagerly_finalized_field_note_ :
+                         diag_finalized_field_note_;
+    ReportDiagnostic(error.member->getLocStart(), diag_error)
+        << dtor << error.field->field();
+    NoteField(error.field, diag_note);
+  }
+}
+
+void DiagnosticsReporter::ClassRequiresFinalization(RecordInfo* info) {
+  ReportDiagnostic(info->record()->getInnerLocStart(),
+                   diag_class_requires_finalization_)
+      << info->record();
+}
+
+void DiagnosticsReporter::ClassDoesNotRequireFinalization(
+    RecordInfo* info) {
+  ReportDiagnostic(info->record()->getInnerLocStart(),
+                   diag_class_does_not_require_finalization_)
+      << info->record();
+}
+
+void DiagnosticsReporter::OverriddenNonVirtualTrace(
+    RecordInfo* info,
+    CXXMethodDecl* trace,
+    CXXMethodDecl* overridden) {
+  ReportDiagnostic(trace->getLocStart(), diag_overridden_non_virtual_trace_)
+      << info->record() << overridden->getParent();
+  NoteOverriddenNonVirtualTrace(overridden);
+}
+
+void DiagnosticsReporter::MissingTraceDispatchMethod(RecordInfo* info) {
+  ReportMissingDispatchMethod(info, diag_missing_trace_dispatch_method_);
+}
+
+void DiagnosticsReporter::MissingFinalizeDispatchMethod(
+    RecordInfo* info) {
+  ReportMissingDispatchMethod(info, diag_missing_finalize_dispatch_method_);
+}
+
+void DiagnosticsReporter::ReportMissingDispatchMethod(
+    RecordInfo* info,
+    unsigned error) {
+  ReportDiagnostic(info->record()->getInnerLocStart(), error)
+      << info->record();
+}
+
+void DiagnosticsReporter::VirtualAndManualDispatch(
+    RecordInfo* info,
+    CXXMethodDecl* dispatch) {
+  ReportDiagnostic(info->record()->getInnerLocStart(),
+                   diag_virtual_and_manual_dispatch_)
+      << info->record();
+  NoteManualDispatchMethod(dispatch);
+}
+
+void DiagnosticsReporter::MissingTraceDispatch(
+    const FunctionDecl* dispatch,
+    RecordInfo* receiver) {
+  ReportMissingDispatch(dispatch, receiver, diag_missing_trace_dispatch_);
+}
+
+void DiagnosticsReporter::MissingFinalizeDispatch(
+    const FunctionDecl* dispatch,
+    RecordInfo* receiver) {
+  ReportMissingDispatch(dispatch, receiver, diag_missing_finalize_dispatch_);
+}
+
+void DiagnosticsReporter::ReportMissingDispatch(
+    const FunctionDecl* dispatch,
+    RecordInfo* receiver,
+    unsigned error) {
+  ReportDiagnostic(dispatch->getLocStart(), error) << receiver->record();
+}
+
+void DiagnosticsReporter::DerivesNonStackAllocated(
+    RecordInfo* info,
+    BasePoint* base) {
+  ReportDiagnostic(base->spec().getLocStart(),
+                   diag_derives_non_stack_allocated_)
+      << info->record() << base->info()->record();
+}
+
+void DiagnosticsReporter::ClassOverridesNew(
+    RecordInfo* info,
+    CXXMethodDecl* newop) {
+  ReportDiagnostic(newop->getLocStart(), diag_class_overrides_new_)
+      << info->record();
+}
+
+void DiagnosticsReporter::ClassDeclaresPureVirtualTrace(
+    RecordInfo* info,
+    CXXMethodDecl* trace) {
+  ReportDiagnostic(trace->getLocStart(),
+                   diag_class_declares_pure_virtual_trace_)
+      << info->record();
+}
+
+void DiagnosticsReporter::LeftMostBaseMustBePolymorphic(
+    RecordInfo* derived,
+    CXXRecordDecl* base) {
+  ReportDiagnostic(base->getLocStart(),
+                   diag_left_most_base_must_be_polymorphic_)
+      << base << derived->record();
+}
+
+void DiagnosticsReporter::BaseClassMustDeclareVirtualTrace(
+    RecordInfo* derived,
+    CXXRecordDecl* base) {
+  ReportDiagnostic(base->getLocStart(),
+                   diag_base_class_must_declare_virtual_trace_)
+      << base << derived->record();
+}
+
+void DiagnosticsReporter::NoteManualDispatchMethod(CXXMethodDecl* dispatch) {
+  ReportDiagnostic(dispatch->getLocStart(),
+                   diag_manual_dispatch_method_note_)
+      << dispatch;
+}
+
+void DiagnosticsReporter::NoteBaseRequiresTracing(BasePoint* base) {
+  ReportDiagnostic(base->spec().getLocStart(),
+                   diag_base_requires_tracing_note_)
+      << base->info()->record();
+}
+
+void DiagnosticsReporter::NoteFieldRequiresTracing(
+    RecordInfo* holder,
+    FieldDecl* field) {
+  NoteField(field, diag_field_requires_tracing_note_);
+}
+
+void DiagnosticsReporter::NotePartObjectContainsGCRoot(FieldPoint* point) {
+  FieldDecl* field = point->field();
+  ReportDiagnostic(field->getLocStart(),
+                   diag_part_object_contains_gc_root_note_)
+      << field << field->getParent();
+}
+
+void DiagnosticsReporter::NoteFieldContainsGCRoot(FieldPoint* point) {
+  NoteField(point, diag_field_contains_gc_root_note_);
+}
+
+void DiagnosticsReporter::NoteUserDeclaredDestructor(CXXMethodDecl* dtor) {
+  ReportDiagnostic(dtor->getLocStart(), diag_user_declared_destructor_note_);
+}
+
+void DiagnosticsReporter::NoteUserDeclaredFinalizer(CXXMethodDecl* dtor) {
+  ReportDiagnostic(dtor->getLocStart(), diag_user_declared_finalizer_note_);
+}
+
+void DiagnosticsReporter::NoteBaseRequiresFinalization(BasePoint* base) {
+  ReportDiagnostic(base->spec().getLocStart(),
+                   diag_base_requires_finalization_note_)
+      << base->info()->record();
+}
+
+void DiagnosticsReporter::NoteFieldRequiresFinalization(FieldPoint* point) {
+  NoteField(point, diag_field_requires_finalization_note_);
+}
+
+void DiagnosticsReporter::NoteField(FieldPoint* point, unsigned note) {
+  NoteField(point->field(), note);
+}
+
+void DiagnosticsReporter::NoteField(FieldDecl* field, unsigned note) {
+  ReportDiagnostic(field->getLocStart(), note) << field;
+}
+
+void DiagnosticsReporter::NoteOverriddenNonVirtualTrace(
+    CXXMethodDecl* overridden) {
+  ReportDiagnostic(overridden->getLocStart(),
+                   diag_overridden_non_virtual_trace_note_)
+      << overridden;
+}