Fix error handling when there are no REPLs installed.

Before, in the absence of any configured REPLs, LLDB would act as if there were
multiple possible REPL options, whereas actually no REPL language is supported.
Now we make a better error.

llvm-svn: 250931

1 files changed, 22 insertions, 0 deletions

diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 494b762e872..2b8e822c4a2 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -1806,6 +1806,28 @@ Debugger::RunREPL (LanguageType language, const char *repl_options)
     Error err;
     FileSpec repl_executable;
     
+    if (language == eLanguageTypeUnknown)
+    {
+        std::set<LanguageType> repl_languages;
+        
+        Language::GetLanguagesSupportingREPLs(repl_languages);
+        
+        if (repl_languages.size() == 1)
+        {
+            language = *repl_languages.begin();
+        }
+        else if (repl_languages.size() == 0)
+        {
+            err.SetErrorStringWithFormat("LLDB isn't configured with support support for any REPLs.");
+            return err;
+        }
+        else
+        {
+            err.SetErrorStringWithFormat("Multiple possible REPL languages.  Please specify a language.");
+            return err;
+        }
+    }
+
     Target *const target = nullptr; // passing in an empty target means the REPL must create one
     
     REPLSP repl_sp(REPL::Create(err, language, this, target, repl_options));