[DWIMPrint] Move the setting of the result status into dump_val_object (llvm#96232)

Previously the result would get overwritten by a success on all code
paths.

This is another NFC change for TypeSystemClang, because an object
description cannot actually fail there. It will have different behavior
in the Swift plugin.

(cherry picked from commit 9473e16)

Author: adrian-prantl

lldb/source/Commands/CommandObjectDWIMPrint.cpp

@@ -150,10 +150,14 @@ void CommandObjectDWIMPrint::DoExecute(StringRef command,
       maybe_add_hint(output);
       result.GetOutputStream() << output;
     } else {
-      if (llvm::Error error =
-              valobj.Dump(result.GetOutputStream(), dump_options))
+      llvm::Error error =
+        valobj.Dump(result.GetOutputStream(), dump_options);
+      if (error) {
         result.AppendError(toString(std::move(error)));
+        return;
+      }
     }
+    result.SetStatus(eReturnStatusSuccessFinishResult);
   };
 
   // First, try `expr` as the name of a frame variable.
@@ -174,7 +178,6 @@ void CommandObjectDWIMPrint::DoExecute(StringRef command,
       }
 
       dump_val_object(*valobj_sp);
-      result.SetStatus(eReturnStatusSuccessFinishResult);
       return;
     }
   }
@@ -222,7 +225,6 @@ void CommandObjectDWIMPrint::DoExecute(StringRef command,
       if (auto var_sp = state->GetVariable(expr))
         if (auto valobj_sp = var_sp->GetValueObject()) {
           dump_val_object(*valobj_sp);
-          result.SetStatus(eReturnStatusSuccessFinishResult);
           return;
         }
 
@@ -243,34 +245,36 @@ void CommandObjectDWIMPrint::DoExecute(StringRef command,
       error_stream << "    " << fixed_expression << "\n";
     }
 
-    if (expr_result == eExpressionCompleted) {
-      if (verbosity != eDWIMPrintVerbosityNone) {
-        StringRef flags;
-        if (args.HasArgs())
-          flags = args.GetArgStringWithDelimiter();
-        result.AppendMessageWithFormatv("note: ran `expression {0}{1}`", flags,
-                                        expr);
-      }
-
-      if (valobj_sp->GetError().GetError() != UserExpression::kNoResult)
-        dump_val_object(*valobj_sp);
-
-      if (suppress_result)
-        if (auto result_var_sp =
-                target.GetPersistentVariable(valobj_sp->GetName())) {
-          auto language = valobj_sp->GetPreferredDisplayLanguage();
-          if (auto *persistent_state =
-                  target.GetPersistentExpressionStateForLanguage(language))
-            persistent_state->RemovePersistentVariable(result_var_sp);
-        }
-
-      result.SetStatus(eReturnStatusSuccessFinishResult);
-    } else {
+    // If the expression failed, return an error.
+    if (expr_result != eExpressionCompleted) {
       if (valobj_sp)
         result.SetError(valobj_sp->GetError());
       else
         result.AppendErrorWithFormatv(
             "unknown error evaluating expression `{0}`", expr);
+      return;
+    }
+
+    if (verbosity != eDWIMPrintVerbosityNone) {
+      StringRef flags;
+      if (args.HasArgs())
+        flags = args.GetArgStringWithDelimiter();
+      result.AppendMessageWithFormatv("note: ran `expression {0}{1}`", flags,
+                                      expr);
     }
+
+    if (valobj_sp->GetError().GetError() != UserExpression::kNoResult)
+      dump_val_object(*valobj_sp);
+    else
+      result.SetStatus(eReturnStatusSuccessFinishResult);
+
+    if (suppress_result)
+      if (auto result_var_sp =
+              target.GetPersistentVariable(valobj_sp->GetName())) {
+        auto language = valobj_sp->GetPreferredDisplayLanguage();
+        if (auto *persistent_state =
+                target.GetPersistentExpressionStateForLanguage(language))
+          persistent_state->RemovePersistentVariable(result_var_sp);
+      }
   }
 }