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 }
82