[lldb] Set result error state in 'frame variable'

Ensure that errors in `frame variable` are reflected in result object.

The statistics for `frame variable` show invocations as being successful, even
when executing one of the error paths.

This change replaces `result.GetErrorStream()` with `result.AppendError()`,
which also sets the status to `eReturnStatusFailed`.

Differential Revision: https://reviews.llvm.org/D116788

(cherry picked from commit 2c7d10c41278181e3e45c68f28b501cd95193a8a)

2 files changed, 20 insertions, 19 deletions

diff --git a/lldb/source/Commands/CommandObjectFrame.cpp b/lldb/source/Commands/CommandObjectFrame.cpp
index 9cfe997f9227..8dd1a79d3895 100644
--- a/lldb/source/Commands/CommandObjectFrame.cpp
+++ b/lldb/source/Commands/CommandObjectFrame.cpp
@@ -558,18 +558,16 @@ protected:
                   }
                 }
               } else if (num_matches == 0) {
-                result.GetErrorStream().Printf("error: no variables matched "
-                                               "the regular expression '%s'.\n",
-                                               entry.c_str());
+                result.AppendErrorWithFormat(
+                    "no variables matched the regular expression '%s'.",
+                    entry.c_str());
               }
             } else {
               if (llvm::Error err = regex.GetError())
-                result.GetErrorStream().Printf(
-                    "error: %s\n", llvm::toString(std::move(err)).c_str());
+                result.AppendError(llvm::toString(std::move(err)));
               else
-                result.GetErrorStream().Printf(
-                    "error: unknown regex error when compiling '%s'\n",
-                    entry.c_str());
+                result.AppendErrorWithFormat(
+                    "unknown regex error when compiling '%s'", entry.c_str());
             }
           } else // No regex, either exact variable names or variable
                  // expressions.
@@ -605,14 +603,13 @@ protected:
                   valobj_sp->GetParent() ? entry.c_str() : nullptr);
               valobj_sp->Dump(output_stream, options);
             } else {
-              const char *error_cstr = error.AsCString(nullptr);
-              if (error_cstr)
-                result.GetErrorStream().Printf("error: %s\n", error_cstr);
+              if (auto error_cstr = error.AsCString(nullptr))
+                result.AppendError(error_cstr);
               else
-                result.GetErrorStream().Printf("error: unable to find any "
-                                               "variable expression path that "
-                                               "matches '%s'.\n",
-                                               entry.c_str());
+                result.AppendErrorWithFormat(
+                    "unable to find any variable expression path that matches "
+                    "'%s'.",
+                    entry.c_str());
             }
           }
         }
@@ -680,7 +677,8 @@ protected:
           }
         }
       }
-      result.SetStatus(eReturnStatusSuccessFinishResult);
+      if (result.GetStatus() != eReturnStatusFailed)
+        result.SetStatus(eReturnStatusSuccessFinishResult);
     }
 
     if (m_option_variable.show_recognized_args) {
diff --git a/lldb/test/API/lang/cpp/frame-var-anon-unions/TestFrameVariableAnonymousUnions.py b/lldb/test/API/lang/cpp/frame-var-anon-unions/TestFrameVariableAnonymousUnions.py
index 6352b68e7d75..2682e42be9ca 100644
--- a/lldb/test/API/lang/cpp/frame-var-anon-unions/TestFrameVariableAnonymousUnions.py
+++ b/lldb/test/API/lang/cpp/frame-var-anon-unions/TestFrameVariableAnonymousUnions.py
@@ -30,6 +30,9 @@ class FrameVariableAnonymousUnionsTestCase(TestBase):
 
         self.expect('frame variable c', substrs=["'A"])
 
-        self.expect('frame variable x', matching=False, substrs=['3'])
-        self.expect('frame variable y', matching=False, substrs=["'B'"])
-        self.expect('frame variable z', matching=False, substrs=['14'])
+        self.expect('frame variable x', error=True,
+                    substrs=["no variable named 'x' found"])
+        self.expect('frame variable y', error=True,
+                    substrs=["no variable named 'y' found"])
+        self.expect('frame variable z', error=True,
+                    substrs=["no variable named 'z' found"])