From 6385c2ab8ff8304eafa822012c40934690bde124 Mon Sep 17 00:00:00 2001
From: Davide Italiano <ditaliano@apple.com>
Date: Fri, 20 Mar 2020 13:42:21 -0700
Subject: [PATCH] [AppleObjCRuntimeV2] Force lazily allocated class names to be
 resolved.

Fixes a couple of tests on new versions of the Obj-C runtime.
---
 .../AppleObjCRuntime/AppleObjCRuntimeV2.cpp   | 34 ++++++++++++++++++-
 .../Shell/ExecControl/StopHook/stop-hook.test |  2 +-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index 9fea9a217dce..4a07c792eebb 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -1175,6 +1175,28 @@ AppleObjCRuntimeV2::GetClassDescriptorFromISA(ObjCISA isa) {
   return class_descriptor_sp;
 }
 
+static std::pair<bool, ConstString> ObjCGetClassNameRaw(
+                                      AppleObjCRuntime::ObjCISA isa,
+                                      Process *process) {
+  StreamString expr_string;
+  std::string input = std::to_string(isa);
+  expr_string.Printf("(const char *)objc_debug_class_getNameRaw(%s)",
+                     input.c_str());
+
+  ValueObjectSP result_sp;
+  EvaluateExpressionOptions eval_options;
+  eval_options.SetLanguage(lldb::eLanguageTypeObjC);
+  eval_options.SetResultIsInternal(true);
+  eval_options.SetGenerateDebugInfo(true);
+  eval_options.SetTimeout(process->GetUtilityExpressionTimeout());
+  auto eval_result = process->GetTarget().EvaluateExpression(
+      expr_string.GetData(),
+      process->GetThreadList().GetSelectedThread()->GetSelectedFrame().get(),
+      result_sp, eval_options);
+  ConstString type_name(result_sp->GetSummaryAsCString());
+  return std::make_pair(eval_result == eExpressionCompleted, type_name);
+}
+
 ObjCLanguageRuntime::ClassDescriptorSP
 AppleObjCRuntimeV2::GetClassDescriptor(ValueObject &valobj) {
   ClassDescriptorSP objc_class_sp;
@@ -1210,7 +1232,10 @@ AppleObjCRuntimeV2::GetClassDescriptor(ValueObject &valobj) {
     return objc_class_sp;
 
   objc_class_sp = GetClassDescriptorFromISA(isa);
-  if (isa && !objc_class_sp) {
+
+  if (objc_class_sp)
+    return objc_class_sp;
+  else {
     Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS |
                                       LIBLLDB_LOG_TYPES));
     LLDB_LOGF(log,
@@ -1219,6 +1244,13 @@ AppleObjCRuntimeV2::GetClassDescriptor(ValueObject &valobj) {
               "not in class descriptor cache 0x%" PRIx64,
               isa_pointer, isa);
   }
+
+  ClassDescriptorSP descriptor_sp(new ClassDescriptorV2(*this, isa, nullptr));
+  auto resolved = ObjCGetClassNameRaw(isa, process);
+  if (resolved.first == true) {
+    AddClass(isa, descriptor_sp, resolved.second.AsCString());
+    objc_class_sp = descriptor_sp;
+  }
   return objc_class_sp;
 }
 
diff --git a/lldb/test/Shell/ExecControl/StopHook/stop-hook.test b/lldb/test/Shell/ExecControl/StopHook/stop-hook.test
index a06de6634ea1..7e5b37b63854 100644
--- a/lldb/test/Shell/ExecControl/StopHook/stop-hook.test
+++ b/lldb/test/Shell/ExecControl/StopHook/stop-hook.test
@@ -51,7 +51,7 @@ run
 thread step-over
 # Stepping inside of the stop hook range
 # CHECK: (lldb) thread step-over
-# CHECK-NEXT: (void *) $1 = 0x
+# CHECK-NEXT: (void *) $2 = 0x
 # CHECK: ->{{.*}} // We should stop here after stepping.
 
 process continue