Index: include/lldb/Target/StackFrame.h
===================================================================
--- include/lldb/Target/StackFrame.h
+++ include/lldb/Target/StackFrame.h
@@ -466,6 +466,16 @@
     TrackGlobalVariable (const lldb::VariableSP &variable_sp, lldb::DynamicValueType use_dynamic);
 
     //------------------------------------------------------------------
+    /// Query this frame to determine what the default language should be
+    /// when parsing expressions given the execution context.
+    ///
+    /// @return
+    ///   The language of the frame if known, else lldb::eLanguageTypeUnknown.
+    //------------------------------------------------------------------
+    lldb::LanguageType
+    GetDefaultExpressionLanguage ();
+
+    //------------------------------------------------------------------
     // lldb::ExecutionContextScope pure virtual functions
     //------------------------------------------------------------------
     virtual lldb::TargetSP
Index: source/Commands/CommandObjectExpression.cpp
===================================================================
--- source/Commands/CommandObjectExpression.cpp
+++ source/Commands/CommandObjectExpression.cpp
@@ -289,8 +289,8 @@
     if (target)
     {
         lldb::ValueObjectSP result_valobj_sp;
-
         bool keep_in_memory = true;
+        StackFrame *frame = exe_ctx.GetFramePtr();
 
         EvaluateExpressionOptions options;
         options.SetCoerceToId(m_varobj_options.use_objc);
@@ -301,11 +301,15 @@
         options.SetTryAllThreads(m_command_options.try_all_threads);
         options.SetDebug(m_command_options.debug);
         
-        // If the language was not specified, set it from target's properties
+        // If the language was not specified in the expression command,
+        // set it to the language in the target's properties if
+        // specified, else default to the langage for the frame.
         if (m_command_options.language != eLanguageTypeUnknown)
             options.SetLanguage(m_command_options.language);
-        else
+        else if (target->GetLanguage() != eLanguageTypeUnknown)
             options.SetLanguage(target->GetLanguage());
+        else if (frame)
+            options.SetLanguage(frame->GetDefaultExpressionLanguage());
 
         // If there is any chance we are going to stop and want to see
         // what went wrong with our expression, we should generate debug info
@@ -318,8 +322,7 @@
         else
             options.SetTimeoutUsec(0);
 
-        target->EvaluateExpression(expr, exe_ctx.GetFramePtr(),
-                                   result_valobj_sp, options);
+        target->EvaluateExpression(expr, frame, result_valobj_sp, options);
 
         if (result_valobj_sp)
         {
Index: source/Expression/ClangExpressionParser.cpp
===================================================================
--- source/Expression/ClangExpressionParser.cpp
+++ source/Expression/ClangExpressionParser.cpp
@@ -214,11 +214,29 @@
     case lldb::eLanguageTypeObjC:
         m_compiler->getLangOpts().ObjC1 = true;
         m_compiler->getLangOpts().ObjC2 = true;
+        // FIXME: the following 2 language options are a temporary workaround,
+        // to "ask for ObjC, get ObjC++."
+        //
+        // In http://reviews.llvm.org/D11482 Jim writes "Sean doesn't have a DESIRE to
+        // have the expression parser use ObjC++ anytime the language is a C family
+        // language. Rather he MUST right now, because the expression parser uses
+        // features of C++ to capture values. We could switch to using C++ in C/C++
+        // situations, and ObjC++ in others, but there wasn't sufficient motivation to
+        // add that. Sometime when we get some spare cycles we'll try to relax the need
+        // for C++, and then we'll truly be able to follow the frame language. For now,
+        // we do "Want C -> get ObjC++", "Want ObjC -> get ObjC++" etc... But again,
+        // that is not a fundamental choice, it is an implementation necessity.
+        m_compiler->getLangOpts().CPlusPlus = true;
+        m_compiler->getLangOpts().CPlusPlus11 = true;
         break;
     case lldb::eLanguageTypeC_plus_plus:
         m_compiler->getLangOpts().CPlusPlus = true;
         m_compiler->getLangOpts().CPlusPlus11 = true;
         m_compiler->getHeaderSearchOpts().UseLibcxx = true;
+        // FIXME: the following 2 language options are a temporary workaround,
+        // to "ask for C++, for now get ObjC++" (see comment above).
+        m_compiler->getLangOpts().ObjC1 = true;
+        m_compiler->getLangOpts().ObjC2 = true;
         break;
     case lldb::eLanguageTypeObjC_plus_plus:
     default:
Index: source/Target/StackFrame.cpp
===================================================================
--- source/Target/StackFrame.cpp
+++ source/Target/StackFrame.cpp
@@ -1316,6 +1316,15 @@
     return false;
 }
 
+lldb::LanguageType
+StackFrame::GetDefaultExpressionLanguage ()
+{
+    CompileUnit *cu = GetSymbolContext(eSymbolContextCompUnit).comp_unit;
+    if (cu)
+        return cu->GetLanguage();
+    return lldb::eLanguageTypeUnknown;
+}
+
 TargetSP
 StackFrame::CalculateTarget ()
 {