Convert the ScriptInterpreter system to a plugin-based one.

Previously embedded interpreters were handled as ad-hoc source
files compiled into source/Interpreter.  This made it hard to
disable a specific interpreter, or to add support for other
interpreters and allow the developer to choose which interpreter(s)
were enabled for a particular build.

This patch converts script interpreters over to a plugin-based system.
Script interpreters now live in source/Plugins/ScriptInterpreter, and
the canonical LLDB interpreter, ScriptInterpreterPython, is moved there
as well.

Any new code interfacing with the Python C API must live in this location
from here on out.  Additionally, generic code should never need to
reference or make assumptions about the presence of a specific interpreter
going forward.

Differential Revision: http://reviews.llvm.org/D11431
Reviewed By: Greg Clayton

llvm-svn: 243681

lldb/source/Plugins/ScriptInterpreter/None/ScriptInterpreterNone.cpp

@@ -0,0 +1,93 @@
+//===-- ScriptInterpreterNone.cpp -------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ScriptInterpreterNone.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/Stream.h"
+#include "lldb/Core/StreamFile.h"
+#include "lldb/Core/StringList.h"
+#include "lldb/Interpreter/CommandInterpreter.h"
+
+#include <mutex>
+
+using namespace lldb;
+using namespace lldb_private;
+
+ScriptInterpreterNone::ScriptInterpreterNone(CommandInterpreter &interpreter)
+    : ScriptInterpreter(interpreter, eScriptLanguageNone)
+{
+}
+
+ScriptInterpreterNone::~ScriptInterpreterNone()
+{
+}
+
+bool
+ScriptInterpreterNone::ExecuteOneLine(const char *command, CommandReturnObject *, const ExecuteScriptOptions &)
+{
+    m_interpreter.GetDebugger().GetErrorFile()->PutCString(
+        "error: there is no embedded script interpreter in this mode.\n");
+    return false;
+}
+
+void
+ScriptInterpreterNone::ExecuteInterpreterLoop()
+{
+    m_interpreter.GetDebugger().GetErrorFile()->PutCString(
+        "error: there is no embedded script interpreter in this mode.\n");
+}
+
+void
+ScriptInterpreterNone::Initialize()
+{
+    static std::once_flag g_once_flag;
+
+    std::call_once(g_once_flag, []()
+                   {
+                       PluginManager::RegisterPlugin(GetPluginNameStatic(), GetPluginDescriptionStatic(),
+                                                     lldb::eScriptLanguageNone, CreateInstance);
+                   });
+}
+
+void
+ScriptInterpreterNone::Terminate()
+{
+}
+
+lldb::ScriptInterpreterSP
+ScriptInterpreterNone::CreateInstance(CommandInterpreter &interpreter)
+{
+    return std::make_shared<ScriptInterpreterNone>(interpreter);
+}
+
+lldb_private::ConstString
+ScriptInterpreterNone::GetPluginNameStatic()
+{
+    static ConstString g_name("script-none");
+    return g_name;
+}
+
+const char *
+ScriptInterpreterNone::GetPluginDescriptionStatic()
+{
+    return "Null script interpreter";
+}
+
+lldb_private::ConstString
+ScriptInterpreterNone::GetPluginName()
+{
+    return GetPluginNameStatic();
+}
+
+uint32_t
+ScriptInterpreterNone::GetPluginVersion()
+{
+    return 1;
+}