lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp

   1 //===-- HexagonDisassembler.cpp - Disassembler for Hexagon ISA ------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "MCTargetDesc/HexagonBaseInfo.h"
  11 #include "MCTargetDesc/HexagonMCTargetDesc.h"
  12
  13 #include "llvm/MC/MCContext.h"
  14 #include "llvm/MC/MCDisassembler.h"
  15 #include "llvm/MC/MCExpr.h"
  16 #include "llvm/MC/MCFixedLenDisassembler.h"
  17 #include "llvm/MC/MCInst.h"
  18 #include "llvm/MC/MCInstrDesc.h"
  19 #include "llvm/MC/MCSubtargetInfo.h"
  20 #include "llvm/Support/Debug.h"
  21 #include "llvm/Support/ErrorHandling.h"
  22 #include "llvm/Support/LEB128.h"
  23 #include "llvm/Support/MemoryObject.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include "llvm/Support/TargetRegistry.h"
  26 #include "llvm/Support/Endian.h"
  27
  28 #include <vector>
  29 #include <array>
  30
  31 using namespace llvm;
  32
  33 #define DEBUG_TYPE "hexagon-disassembler"
  34
  35 // Pull DecodeStatus and its enum values into the global namespace.
  36 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
  37
  38 namespace {
  39 /// \brief Hexagon disassembler for all Hexagon platforms.
  40 class HexagonDisassembler : public MCDisassembler {
  41 public:
  42   HexagonDisassembler(MCSubtargetInfo const &STI, MCContext &Ctx)
  43       : MCDisassembler(STI, Ctx) {}
  44
  45   DecodeStatus getInstruction(MCInst &instr, uint64_t &size,
  46                               MemoryObject const &region, uint64_t address,
  47                               raw_ostream &vStream, raw_ostream &cStream) const override;
  48 };
  49 }
  50
  51 #include "HexagonGenDisassemblerTables.inc"
  52
  53 static MCDisassembler *createHexagonDisassembler(Target const &T,
  54                                                  MCSubtargetInfo const &STI,
  55                                                  MCContext &Ctx) {
  56   return new HexagonDisassembler(STI, Ctx);
  57 }
  58
  59 extern "C" void LLVMInitializeHexagonDisassembler() {
  60   TargetRegistry::RegisterMCDisassembler(TheHexagonTarget,
  61                                          createHexagonDisassembler);
  62 }
  63
  64 DecodeStatus HexagonDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
  65                                                  MemoryObject const &Region,
  66                                                  uint64_t Address,
  67                                                  raw_ostream &os,
  68                                                  raw_ostream &cs) const {
  69   std::array<uint8_t, 4> Bytes;
  70   Size = 4;
  71   if (Region.readBytes(Address, Bytes.size(), Bytes.data()) == -1) {
  72     return MCDisassembler::Fail;
  73   }
  74   uint32_t insn =
  75       llvm::support::endian::read<uint32_t, llvm::support::little,
  76                                   llvm::support::unaligned>(Bytes.data());
  77
  78   // Remove parse bits.
  79   insn &= ~static_cast<uint32_t>(HexagonII::InstParseBits::INST_PARSE_MASK);
  80   return decodeInstruction(DecoderTable32, MI, insn, Address, this, STI);
  81 }