Change ValueObject::GetData to return llvm::Expected

Author: wizardengineer

lldb/include/lldb/ValueObject/ValueObject.h

@@ -757,7 +757,7 @@ class ValueObject {
   virtual size_t GetPointeeData(DataExtractor &data, uint32_t item_idx = 0,
                                 uint32_t item_count = 1);
 
-  virtual uint64_t GetData(DataExtractor &data, Status &error);
+  virtual llvm::Expected<DataExtractor> GetData();
 
   virtual bool SetData(DataExtractor &data, Status &error);
 

lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp

@@ -551,9 +551,8 @@ ThreadSP AppleObjCRuntime::GetBacktraceThreadFromException(
 
     DataExtractor data;
     data.SetAddressByteSize(dict_entry->GetProcessSP()->GetAddressByteSize());
-    Status error;
-    dict_entry->GetData(data, error);
-    if (error.Fail()) return ThreadSP();
+    auto data_or_err = dict_entry->GetData();
+    if (!data_or_err) return ThreadSP();
 
     lldb::offset_t data_offset = 0;
     auto dict_entry_key = data.GetAddress(&data_offset);

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -247,13 +247,15 @@ static lldb::addr_t GetVTableAddress(Process &process,
   // We have an object already read from process memory,
   // so just extract VTable pointer from it
 
-  DataExtractor data;
-  Status err;
-  auto size = valobj.GetData(data, err);
-  if (err.Fail() || vbtable_ptr_offset + data.GetAddressByteSize() > size)
+  auto data_or_err = valobj.GetData();
+  if (!data_or_err)
+    return LLDB_INVALID_ADDRESS;
+
+  auto size = data_or_err->GetByteSize();
+  if (vbtable_ptr_offset + data_or_err->GetAddressByteSize() > size)
     return LLDB_INVALID_ADDRESS;
 
-  return data.GetAddress(&vbtable_ptr_offset);
+  return data_or_err->GetAddress(&vbtable_ptr_offset);
 }
 
 static int64_t ReadVBaseOffsetFromVTable(Process &process,

lldb/source/ValueObject/ValueObject.cpp

@@ -691,13 +691,20 @@ size_t ValueObject::GetPointeeData(DataExtractor &data, uint32_t item_idx,
       ValueObjectSP pointee_sp = Dereference(error);
       if (error.Fail() || pointee_sp.get() == nullptr)
         return 0;
-      return pointee_sp->GetData(data, error);
+      auto data_or_err = pointee_sp->GetData();
+      if (!data_or_err)
+        return 0;
+      data = *data_or_err;
+      return data.GetByteSize();
     } else {
       ValueObjectSP child_sp = GetChildAtIndex(0);
       if (child_sp.get() == nullptr)
         return 0;
-      Status error;
-      return child_sp->GetData(data, error);
+      auto data_or_err = child_sp->GetData();
+      if (!data_or_err)
+        return 0;
+      data = *data_or_err;
+      return data.GetByteSize();
     }
     return true;
   } else /* (items > 1) */
@@ -764,22 +771,27 @@ size_t ValueObject::GetPointeeData(DataExtractor &data, uint32_t item_idx,
   return 0;
 }
 
-uint64_t ValueObject::GetData(DataExtractor &data, Status &error) {
+llvm::Expected<DataExtractor> ValueObject::GetData() {
   UpdateValueIfNeeded(false);
   ExecutionContext exe_ctx(GetExecutionContextRef());
-  error = m_value.GetValueAsData(&exe_ctx, data, GetModule().get());
+  DataExtractor data;
+  Status error = m_value.GetValueAsData(&exe_ctx, data, GetModule().get());
   if (error.Fail()) {
     if (m_data.GetByteSize()) {
       data = m_data;
       error.Clear();
-      return data.GetByteSize();
+      data.SetAddressByteSize(m_data.GetAddressByteSize());
+      data.SetByteOrder(m_data.GetByteOrder());
+      return data;
     } else {
-      return 0;
+      return llvm::createStringError(
+          "GetData failed: %s",
+          error.AsCString());
     }
   }
   data.SetAddressByteSize(m_data.GetAddressByteSize());
   data.SetByteOrder(m_data.GetByteOrder());
-  return data.GetByteSize();
+  return data;
 }
 
 bool ValueObject::SetData(DataExtractor &data, Status &error) {