[WebAssembly] Initial Disassembler.

This implements a new table-gen emitter to create tables for
a wasm disassembler, and a dissassembler to use them.

Comes with 2 tests, that tests a few instructions manually. Is also able to
disassemble large .wasm files with objdump reasonably.

Not working so well, to be addressed in followups:
- objdump appears to be passing an incorrect starting point.
- since the disassembler works an instruction at a time, and it is
  disassembling stack instruction, it has no idea of pseudo register assignments.
  These registers are required for the instruction printing code that follows.
  For now, all such registers appear in the output as $0.

Patch by Wouter van Oortmerssen

Differential Revision: https://reviews.llvm.org/D45848

llvm-svn: 332052

1 files changed, 5 insertions, 9 deletions

diff --git a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
index 6629ce6cda0..10fa798ac8d 100644
--- a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
@@ -46,7 +46,7 @@ void WebAssemblyInstPrinter::printRegName(raw_ostream &OS,
 
 void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
                                        StringRef Annot,
-                                       const MCSubtargetInfo & /*STI*/) {
+                                       const MCSubtargetInfo &STI) {
   // Print the instruction (this uses the AsmStrings from the .td files).
   printInstruction(MI, OS);
 
@@ -194,20 +194,16 @@ void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
   }
 }
 
-void
-WebAssemblyInstPrinter::printWebAssemblyP2AlignOperand(const MCInst *MI,
-                                                       unsigned OpNo,
-                                                       raw_ostream &O) {
+void WebAssemblyInstPrinter::printWebAssemblyP2AlignOperand(
+    const MCInst *MI, unsigned OpNo, raw_ostream &O) {
   int64_t Imm = MI->getOperand(OpNo).getImm();
   if (Imm == WebAssembly::GetDefaultP2Align(MI->getOpcode()))
     return;
   O << ":p2align=" << Imm;
 }
 
-void
-WebAssemblyInstPrinter::printWebAssemblySignatureOperand(const MCInst *MI,
-                                                         unsigned OpNo,
-                                                         raw_ostream &O) {
+void WebAssemblyInstPrinter::printWebAssemblySignatureOperand(
+    const MCInst *MI, unsigned OpNo, raw_ostream &O) {
   int64_t Imm = MI->getOperand(OpNo).getImm();
   switch (WebAssembly::ExprType(Imm)) {
   case WebAssembly::ExprType::Void: break;