MC: Add MCAsmParserExtension, a base class for all the target/object specific
classes which want to extend the basic asm parser.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108158 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index a8f2bbd..01bc917 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -47,6 +47,12 @@
 AsmParser::~AsmParser() {
 }
 
+void AsmParser::setTargetParser(TargetAsmParser &P) {
+  assert(!TargetParser && "Target parser is already initialized!");
+  TargetParser = &P;
+  TargetParser->Initialize(*this);
+}
+
 void AsmParser::Warning(SMLoc L, const Twine &Msg) {
   PrintMessage(L, Msg.str(), "warning");
 }
diff --git a/lib/MC/MCParser/CMakeLists.txt b/lib/MC/MCParser/CMakeLists.txt
index a5c0818..4dae5ea 100644
--- a/lib/MC/MCParser/CMakeLists.txt
+++ b/lib/MC/MCParser/CMakeLists.txt
@@ -3,5 +3,6 @@
   AsmParser.cpp
   MCAsmLexer.cpp
   MCAsmParser.cpp
+  MCAsmParserExtension.cpp
   TargetAsmParser.cpp
   )
diff --git a/lib/MC/MCParser/MCAsmParserExtension.cpp b/lib/MC/MCParser/MCAsmParserExtension.cpp
new file mode 100644
index 0000000..c30d306
--- /dev/null
+++ b/lib/MC/MCParser/MCAsmParserExtension.cpp
@@ -0,0 +1,21 @@
+//===-- MCAsmParserExtension.cpp - Asm Parser Hooks -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCParser/MCAsmParserExtension.h"
+using namespace llvm;
+
+MCAsmParserExtension::MCAsmParserExtension() {
+}
+
+MCAsmParserExtension::~MCAsmParserExtension() {
+}
+
+void MCAsmParserExtension::Initialize(MCAsmParser &Parser) {
+  this->Parser = &Parser;
+}