[lldb] Propagate ExpressionErrors from ValueObjectPrinter::GetDescriptionForDisplay

Author: kastiglione

lldb/source/DataFormatters/ValueObjectPrinter.cpp

@@ -9,6 +9,7 @@
 #include "lldb/DataFormatters/ValueObjectPrinter.h"
 
 #include "lldb/DataFormatters/DataVisualization.h"
+#include "lldb/Expression/DiagnosticManager.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Target/Language.h"
 #include "lldb/Target/Target.h"
@@ -150,6 +151,11 @@ llvm::Expected<std::string> ValueObjectPrinter::GetDescriptionForDisplay() {
   if (maybe_str)
     return maybe_str;
 
+  if (maybe_str.errorIsA<lldb_private::ExpressionError>())
+    // Propagate expression errors to expose diagnostics to the user.
+    // Without this early exit, the summary/value may be shown without errors.
+    return maybe_str;
+
   const char *str = nullptr;
   if (!str)
     str = valobj.GetSummaryAsCString();