Detect unsupported languages

Author: JDevlieghere

lldb/source/Commands/CommandObjectBreakpoint.cpp

@@ -155,11 +155,18 @@ class lldb_private::BreakpointOptionGroup : public OptionGroup {
     } break;
     case 'Y': {
       LanguageType language = Language::GetLanguageTypeFromString(option_arg);
-      if (language != eLanguageTypeUnknown)
-        m_bp_opts.GetCondition().SetLanguage(language);
-      else
+
+      LanguageSet languages_for_expressions =
+          Language::GetLanguagesSupportingTypeSystemsForExpressions();
+      if (language == eLanguageTypeUnknown)
         error = Status::FromError(CreateOptionParsingError(
             option_arg, short_option, long_option, "invalid language"));
+      else if (!languages_for_expressions[language])
+        error = Status::FromError(
+            CreateOptionParsingError(option_arg, short_option, long_option,
+                                     "no expression support for language"));
+      else
+        m_bp_opts.GetCondition().SetLanguage(language);
     } break;
     default:
       llvm_unreachable("Unimplemented option");

lldb/test/Shell/Breakpoint/condition-lang.test

@@ -0,0 +1,5 @@
+RUN: not %lldb -b -o 'break set -n foo -c bar -Y bogus' 2>&1 | FileCheck %s --check-prefix INVALID
+INVALID: error: Invalid value ('bogus') for -Y (condition-language): invalid language
+
+RUN: not %lldb -b -o 'break set -n foo -c bar -Y python' 2>&1 | FileCheck %s --check-prefix NOEXPRSUPPORT
+NOEXPRSUPPORT: error: Invalid value ('python') for -Y (condition-language): no expression support for language