[lldb] Refactor away UB in SBValue::GetLoadAddress (#141799)

The problem was in calling GetLoadAddress on a value in the error state,
where `ValueObject::GetLoadAddress` could end up accessing the
uninitialized "address type" by-ref return value from `GetAddressOf`.
This probably happened because each function expected the other to
initialize it.

We can guarantee initialization by turning this into a proper return
value.

I've added a test, but it only (reliably) crashes if lldb is built with
ubsan.

1 files changed, 8 insertions, 7 deletions

diff --git a/lldb/source/DataFormatters/FormattersHelpers.cpp b/lldb/source/DataFormatters/FormattersHelpers.cpp
index 5f5541c35262..d7b058d91c4a 100644
--- a/lldb/source/DataFormatters/FormattersHelpers.cpp
+++ b/lldb/source/DataFormatters/FormattersHelpers.cpp
@@ -113,15 +113,16 @@ lldb_private::formatters::ExtractIndexFromString(const char *item_name) {
 
 Address
 lldb_private::formatters::GetArrayAddressOrPointerValue(ValueObject &valobj) {
-  lldb::addr_t data_addr = LLDB_INVALID_ADDRESS;
-  AddressType type;
+  ValueObject::AddrAndType data_addr;
 
   if (valobj.IsPointerType())
-    data_addr = valobj.GetPointerValue(&type);
+    data_addr = valobj.GetPointerValue();
   else if (valobj.IsArrayType())
-    data_addr = valobj.GetAddressOf(/*scalar_is_load_address=*/true, &type);
-  if (data_addr != LLDB_INVALID_ADDRESS && type == eAddressTypeFile)
-    return Address(data_addr, valobj.GetModule()->GetSectionList());
+    data_addr = valobj.GetAddressOf(/*scalar_is_load_address=*/true);
 
-  return data_addr;
+  if (data_addr.address != LLDB_INVALID_ADDRESS &&
+      data_addr.type == eAddressTypeFile)
+    return Address(data_addr.address, valobj.GetModule()->GetSectionList());
+
+  return data_addr.address;
 }