Factor out expression result error strings.

Author: adrian-prantl

lldb/include/lldb/Utility/ErrorMessages.h

@@ -0,0 +1,22 @@
+//===-- ErrorMessages.h -----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_UTILITY_ERROR_MESSAGES_H
+#define LLDB_UTILITY_ERROR_MESSAGES_H
+
+#include "lldb/lldb-defines.h"
+#include "lldb/lldb-enumerations.h"
+#include <string>
+
+namespace lldb_private {
+
+/// Produce a human-readable rendition of an ExpressionResults value.
+std::string toString(lldb::ExpressionResults e);
+
+} // namespace lldb_private
+#endif

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -48,6 +48,7 @@
 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Host/StreamFile.h"
+#include "lldb/Utility/ErrorMessages.h"
 #include "lldb/Utility/LLDBLog.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/State.h"
@@ -1817,51 +1818,8 @@ CommandInterpreter::PreprocessToken(std::string &expr_str) {
     error = expr_result_valobj_sp->GetError();
 
   if (error.Success()) {
-    switch (expr_result) {
-    case eExpressionSetupError:
-      error.SetErrorStringWithFormat(
-          "expression setup error for the expression '%s'", expr_str.c_str());
-      break;
-    case eExpressionParseError:
-      error.SetErrorStringWithFormat(
-          "expression parse error for the expression '%s'", expr_str.c_str());
-      break;
-    case eExpressionResultUnavailable:
-      error.SetErrorStringWithFormat(
-          "expression error fetching result for the expression '%s'",
-          expr_str.c_str());
-      break;
-    case eExpressionCompleted:
-      break;
-    case eExpressionDiscarded:
-      error.SetErrorStringWithFormat(
-          "expression discarded for the expression '%s'", expr_str.c_str());
-      break;
-    case eExpressionInterrupted:
-      error.SetErrorStringWithFormat(
-          "expression interrupted for the expression '%s'", expr_str.c_str());
-      break;
-    case eExpressionHitBreakpoint:
-      error.SetErrorStringWithFormat(
-          "expression hit breakpoint for the expression '%s'",
-          expr_str.c_str());
-      break;
-    case eExpressionTimedOut:
-      error.SetErrorStringWithFormat(
-          "expression timed out for the expression '%s'", expr_str.c_str());
-      break;
-    case eExpressionStoppedForDebug:
-      error.SetErrorStringWithFormat("expression stop at entry point "
-                                     "for debugging for the "
-                                     "expression '%s'",
-                                     expr_str.c_str());
-      break;
-    case eExpressionThreadVanished:
-      error.SetErrorStringWithFormat(
-          "expression thread vanished for the expression '%s'",
-          expr_str.c_str());
-      break;
-    }
+    std::string result = lldb_private::toString(expr_result);
+    error.SetErrorString(result + "for the expression '" + expr_str + "'");
   }
   return error;
 }

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

@@ -31,6 +31,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/ErrorMessages.h"
 #include "lldb/Utility/LLDBLog.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Scalar.h"
@@ -201,7 +202,7 @@ AppleObjCRuntime::GetObjectDescription(Stream &strm, Value &value,
       exe_ctx, &wrapper_struct_addr, options, diagnostics, ret);
   if (results != eExpressionCompleted)
     return llvm::createStringError(
-        "Error evaluating Print Object function: %d.\n", results);
+        "could not evaluate print object function: " + toString(results));
 
   addr_t result_ptr = ret.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
 

lldb/source/Utility/CMakeLists.txt

@@ -39,6 +39,7 @@ add_lldb_library(lldbUtility NO_INTERNAL_DEPENDENCIES
   DataExtractor.cpp
   Diagnostics.cpp
   Environment.cpp
+  ErrorMessages.cpp
   Event.cpp
   FileSpec.cpp
   FileSpecList.cpp

lldb/source/Utility/ErrorMessages.cpp

@@ -0,0 +1,40 @@
+//===-- ErrorMessages.cpp -------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/ErrorMessages.h"
+#include "llvm/Support/ErrorHandling.h"
+
+namespace lldb_private {
+
+std::string toString(lldb::ExpressionResults e) {
+  switch (e) {
+  case lldb::eExpressionSetupError:
+    return "expression setup error";
+  case lldb::eExpressionParseError:
+    return "expression parse error";
+  case lldb::eExpressionResultUnavailable:
+    return "expression error";
+  case lldb::eExpressionCompleted:
+    return "expression completed successfully";
+  case lldb::eExpressionDiscarded:
+    return "expression discarded";
+  case lldb::eExpressionInterrupted:
+    return "expression interrupted";
+  case lldb::eExpressionHitBreakpoint:
+    return "expression hit breakpoint";
+  case lldb::eExpressionTimedOut:
+    return "expression timed out";
+  case lldb::eExpressionStoppedForDebug:
+    return "expression stop at entry point for debugging";
+  case lldb::eExpressionThreadVanished:
+    return "expression thread vanished";
+  }
+  llvm_unreachable("unhandled enumerator");
+}
+
+} // namespace lldb_private