[WebAssembly] Initial WebAssembly backend

This WebAssembly backend is just a skeleton at this time and is not yet
functional.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241022 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp

@@ -0,0 +1,43 @@
+//=- WebAssemblyInstPrinter.cpp - WebAssembly assembly instruction printing -=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Print MCInst instructions to wasm format.
+///
+//===----------------------------------------------------------------------===//
+
+#include "InstPrinter/WebAssemblyInstPrinter.h"
+#include "WebAssembly.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormattedStream.h"
+#include <cctype>
+using namespace llvm;
+
+#define DEBUG_TYPE "asm-printer"
+
+WebAssemblyInstPrinter::WebAssemblyInstPrinter(const MCAsmInfo &MAI,
+                                               const MCInstrInfo &MII,
+                                               const MCRegisterInfo &MRI)
+    : MCInstPrinter(MAI, MII, MRI) {}
+
+void WebAssemblyInstPrinter::printRegName(raw_ostream &OS,
+                                          unsigned RegNo) const {
+  llvm_unreachable("TODO: implement printRegName");
+}
+
+void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
+                                       StringRef Annot,
+                                       const MCSubtargetInfo &STI) {
+  llvm_unreachable("TODO: implement printInst");
+}