| //===- Disassembler.cpp - Disassembler for hex strings --------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This class implements the disassembler of strings of bytes written in |
| // hexadecimal, from standard input or from a file. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "Disassembler.h" |
| #include "llvm/ADT/Triple.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCDisassembler/MCDisassembler.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCRegisterInfo.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/MC/TargetRegistry.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace llvm; |
| |
| typedef std::pair<std::vector<unsigned char>, std::vector<const char *>> |
| ByteArrayTy; |
| |
| static bool PrintInsts(const MCDisassembler &DisAsm, const ByteArrayTy &Bytes, |
| SourceMgr &SM, raw_ostream &Out, MCStreamer &Streamer, |
| bool InAtomicBlock, const MCSubtargetInfo &STI) { |
| ArrayRef<uint8_t> Data(Bytes.first.data(), Bytes.first.size()); |
| |
| // Disassemble it to strings. |
| uint64_t Size; |
| uint64_t Index; |
| |
| for (Index = 0; Index < Bytes.first.size(); Index += Size) { |
| MCInst Inst; |
| |
| MCDisassembler::DecodeStatus S; |
| S = DisAsm.getInstruction(Inst, Size, Data.slice(Index), Index, nulls()); |
| switch (S) { |
| case MCDisassembler::Fail: |
| SM.PrintMessage(SMLoc::getFromPointer(Bytes.second[Index]), |
| SourceMgr::DK_Warning, "invalid instruction encoding"); |
| // Don't try to resynchronise the stream in a block |
| if (InAtomicBlock) |
| return true; |
| |
| if (Size == 0) |
| Size = 1; // skip illegible bytes |
| |
| break; |
| |
| case MCDisassembler::SoftFail: |
| SM.PrintMessage(SMLoc::getFromPointer(Bytes.second[Index]), |
| SourceMgr::DK_Warning, |
| "potentially undefined instruction encoding"); |
| LLVM_FALLTHROUGH; |
| |
| case MCDisassembler::Success: |
| Streamer.emitInstruction(Inst, STI); |
| break; |
| } |
| } |
| |
| return false; |
| } |
| |
| static bool SkipToToken(StringRef &Str) { |
| for (;;) { |
| if (Str.empty()) |
| return false; |
| |
| // Strip horizontal whitespace and commas. |
| if (size_t Pos = Str.find_first_not_of(" \t\r\n,")) { |
| Str = Str.substr(Pos); |
| continue; |
| } |
| |
| // If this is the start of a comment, remove the rest of the line. |
| if (Str[0] == '#') { |
| Str = Str.substr(Str.find_first_of('\n')); |
| continue; |
| } |
| return true; |
| } |
| } |
| |
| static bool ByteArrayFromString(ByteArrayTy &ByteArray, StringRef &Str, |
| SourceMgr &SM) { |
| while (SkipToToken(Str)) { |
| // Handled by higher level |
| if (Str[0] == '[' || Str[0] == ']') |
| return false; |
| |
| // Get the current token. |
| size_t Next = Str.find_first_of(" \t\n\r,#[]"); |
| StringRef Value = Str.substr(0, Next); |
| |
| // Convert to a byte and add to the byte vector. |
| unsigned ByteVal; |
| if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) { |
| // If we have an error, print it and skip to the end of line. |
| SM.PrintMessage(SMLoc::getFromPointer(Value.data()), SourceMgr::DK_Error, |
| "invalid input token"); |
| Str = Str.substr(Str.find('\n')); |
| ByteArray.first.clear(); |
| ByteArray.second.clear(); |
| continue; |
| } |
| |
| ByteArray.first.push_back(ByteVal); |
| ByteArray.second.push_back(Value.data()); |
| Str = Str.substr(Next); |
| } |
| |
| return false; |
| } |
| |
| int Disassembler::disassemble(const Target &T, const std::string &TripleName, |
| MCSubtargetInfo &STI, MCStreamer &Streamer, |
| MemoryBuffer &Buffer, SourceMgr &SM, |
| raw_ostream &Out) { |
| std::unique_ptr<const MCRegisterInfo> MRI(T.createMCRegInfo(TripleName)); |
| if (!MRI) { |
| errs() << "error: no register info for target " << TripleName << "\n"; |
| return -1; |
| } |
| |
| MCTargetOptions MCOptions; |
| std::unique_ptr<const MCAsmInfo> MAI( |
| T.createMCAsmInfo(*MRI, TripleName, MCOptions)); |
| if (!MAI) { |
| errs() << "error: no assembly info for target " << TripleName << "\n"; |
| return -1; |
| } |
| |
| // Set up the MCContext for creating symbols and MCExpr's. |
| MCContext Ctx(Triple(TripleName), MAI.get(), MRI.get(), &STI); |
| |
| std::unique_ptr<const MCDisassembler> DisAsm( |
| T.createMCDisassembler(STI, Ctx)); |
| if (!DisAsm) { |
| errs() << "error: no disassembler for target " << TripleName << "\n"; |
| return -1; |
| } |
| |
| // Set up initial section manually here |
| Streamer.initSections(false, STI); |
| |
| bool ErrorOccurred = false; |
| |
| // Convert the input to a vector for disassembly. |
| ByteArrayTy ByteArray; |
| StringRef Str = Buffer.getBuffer(); |
| bool InAtomicBlock = false; |
| |
| while (SkipToToken(Str)) { |
| ByteArray.first.clear(); |
| ByteArray.second.clear(); |
| |
| if (Str[0] == '[') { |
| if (InAtomicBlock) { |
| SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error, |
| "nested atomic blocks make no sense"); |
| ErrorOccurred = true; |
| } |
| InAtomicBlock = true; |
| Str = Str.drop_front(); |
| continue; |
| } else if (Str[0] == ']') { |
| if (!InAtomicBlock) { |
| SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error, |
| "attempt to close atomic block without opening"); |
| ErrorOccurred = true; |
| } |
| InAtomicBlock = false; |
| Str = Str.drop_front(); |
| continue; |
| } |
| |
| // It's a real token, get the bytes and emit them |
| ErrorOccurred |= ByteArrayFromString(ByteArray, Str, SM); |
| |
| if (!ByteArray.first.empty()) |
| ErrorOccurred |= |
| PrintInsts(*DisAsm, ByteArray, SM, Out, Streamer, InAtomicBlock, STI); |
| } |
| |
| if (InAtomicBlock) { |
| SM.PrintMessage(SMLoc::getFromPointer(Str.data()), SourceMgr::DK_Error, |
| "unclosed atomic block"); |
| ErrorOccurred = true; |
| } |
| |
| return ErrorOccurred; |
| } |