//===-- llvm-mc.cpp - Machine Code Hacking Driver -------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This utility is a simple driver that allows command line hacking on machine
// code.
//
//===----------------------------------------------------------------------===//

#include "llvm/MC/MCParser/AsmLexer.h"
#include "llvm/MC/MCParser/MCAsmLexer.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetAsmParser.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetSelect.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/system_error.h"
#include "Disassembler.h"
using namespace llvm;

static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));

static cl::opt<std::string>
OutputFilename("o", cl::desc("Output filename"),
               cl::value_desc("filename"));

static cl::opt<bool>
ShowEncoding("show-encoding", cl::desc("Show instruction encodings"));

static cl::opt<bool>
ShowInst("show-inst", cl::desc("Show internal instruction representation"));

static cl::opt<bool>
ShowInstOperands("show-inst-operands",
                 cl::desc("Show instructions operands as parsed"));

static cl::opt<unsigned>
OutputAsmVariant("output-asm-variant",
                 cl::desc("Syntax variant to use for output printing"));

static cl::opt<bool>
RelaxAll("mc-relax-all", cl::desc("Relax all fixups"));

static cl::opt<bool>
NoExecStack("mc-no-exec-stack", cl::desc("File doesn't need an exec stack"));

static cl::opt<bool>
EnableLogging("enable-api-logging", cl::desc("Enable MC API logging"));

enum OutputFileType {
  OFT_Null,
  OFT_AssemblyFile,
  OFT_ObjectFile
};
static cl::opt<OutputFileType>
FileType("filetype", cl::init(OFT_AssemblyFile),
  cl::desc("Choose an output file type:"),
  cl::values(
       clEnumValN(OFT_AssemblyFile, "asm",
                  "Emit an assembly ('.s') file"),
       clEnumValN(OFT_Null, "null",
                  "Don't emit anything (for timing purposes)"),
       clEnumValN(OFT_ObjectFile, "obj",
                  "Emit a native object ('.o') file"),
       clEnumValEnd));

static cl::list<std::string>
IncludeDirs("I", cl::desc("Directory of include files"),
            cl::value_desc("directory"), cl::Prefix);

static cl::opt<std::string>
ArchName("arch", cl::desc("Target arch to assemble for, "
                          "see -version for available targets"));

static cl::opt<std::string>
TripleName("triple", cl::desc("Target triple to assemble for, "
                              "see -version for available targets"));

static cl::opt<std::string>
MCPU("mcpu",
     cl::desc("Target a specific cpu type (-mcpu=help for details)"),
     cl::value_desc("cpu-name"),
     cl::init(""));

static cl::opt<Reloc::Model>
RelocModel("relocation-model",
             cl::desc("Choose relocation model"),
             cl::init(Reloc::Default),
             cl::values(
            clEnumValN(Reloc::Default, "default",
                       "Target default relocation model"),
            clEnumValN(Reloc::Static, "static",
                       "Non-relocatable code"),
            clEnumValN(Reloc::PIC_, "pic",
                       "Fully relocatable, position independent code"),
            clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
                       "Relocatable external references, non-relocatable code"),
            clEnumValEnd));

static cl::opt<llvm::CodeModel::Model>
CMModel("code-model",
        cl::desc("Choose code model"),
        cl::init(CodeModel::Default),
        cl::values(clEnumValN(CodeModel::Default, "default",
                              "Target default code model"),
                   clEnumValN(CodeModel::Small, "small",
                              "Small code model"),
                   clEnumValN(CodeModel::Kernel, "kernel",
                              "Kernel code model"),
                   clEnumValN(CodeModel::Medium, "medium",
                              "Medium code model"),
                   clEnumValN(CodeModel::Large, "large",
                              "Large code model"),
                   clEnumValEnd));

static cl::opt<bool>
NoInitialTextSection("n", cl::desc("Don't assume assembly file starts "
                                   "in the text section"));

static cl::opt<bool>
SaveTempLabels("L", cl::desc("Don't discard temporary labels"));

enum ActionType {
  AC_AsLex,
  AC_Assemble,
  AC_Disassemble,
  AC_EDisassemble
};

static cl::opt<ActionType>
Action(cl::desc("Action to perform:"),
       cl::init(AC_Assemble),
       cl::values(clEnumValN(AC_AsLex, "as-lex",
                             "Lex tokens from a .s file"),
                  clEnumValN(AC_Assemble, "assemble",
                             "Assemble a .s file (default)"),
                  clEnumValN(AC_Disassemble, "disassemble",
                             "Disassemble strings of hex bytes"),
                  clEnumValN(AC_EDisassemble, "edis",
                             "Enhanced disassembly of strings of hex bytes"),
                  clEnumValEnd));

static const Target *GetTarget(const char *ProgName) {
  // Figure out the target triple.
  if (TripleName.empty())
    TripleName = sys::getHostTriple();
  Triple TheTriple(Triple::normalize(TripleName));

  const Target *TheTarget = 0;
  if (!ArchName.empty()) {
    for (TargetRegistry::iterator it = TargetRegistry::begin(),
           ie = TargetRegistry::end(); it != ie; ++it) {
      if (ArchName == it->getName()) {
        TheTarget = &*it;
        break;
      }
    }

    if (!TheTarget) {
      errs() << ProgName << ": error: invalid target '" << ArchName << "'.\n";
      return 0;
    }

    // Adjust the triple to match (if known), otherwise stick with the
    // module/host triple.
    Triple::ArchType Type = Triple::getArchTypeForLLVMName(ArchName);
    if (Type != Triple::UnknownArch)
      TheTriple.setArch(Type);
  } else {
    // Get the target specific parser.
    std::string Error;
    TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Error);
    if (TheTarget == 0) {
      errs() << ProgName << ": error: unable to get target for '"
             << TheTriple.getTriple()
             << "', see --version and --triple.\n";
      return 0;
    }
  }

  TripleName = TheTriple.getTriple();
  return TheTarget;
}

static tool_output_file *GetOutputStream() {
  if (OutputFilename == "")
    OutputFilename = "-";

  std::string Err;
  tool_output_file *Out = new tool_output_file(OutputFilename.c_str(), Err,
                                               raw_fd_ostream::F_Binary);
  if (!Err.empty()) {
    errs() << Err << '\n';
    delete Out;
    return 0;
  }

  return Out;
}

static int AsLexInput(const char *ProgName) {
  OwningPtr<MemoryBuffer> BufferPtr;
  if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFilename, BufferPtr)) {
    errs() << ProgName << ": " << ec.message() << '\n';
    return 1;
  }
  MemoryBuffer *Buffer = BufferPtr.take();

  SourceMgr SrcMgr;

  // Tell SrcMgr about this buffer, which is what TGParser will pick up.
  SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());

  // Record the location of the include directories so that the lexer can find
  // it later.
  SrcMgr.setIncludeDirs(IncludeDirs);

  const Target *TheTarget = GetTarget(ProgName);
  if (!TheTarget)
    return 1;

  llvm::OwningPtr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(TripleName));
  assert(MAI && "Unable to create target asm info!");

  AsmLexer Lexer(*MAI);
  Lexer.setBuffer(SrcMgr.getMemoryBuffer(0));

  OwningPtr<tool_output_file> Out(GetOutputStream());
  if (!Out)
    return 1;

  bool Error = false;
  while (Lexer.Lex().isNot(AsmToken::Eof)) {
    AsmToken Tok = Lexer.getTok();

    switch (Tok.getKind()) {
    default:
      SrcMgr.PrintMessage(Lexer.getLoc(), "unknown token", "warning");
      Error = true;
      break;
    case AsmToken::Error:
      Error = true; // error already printed.
      break;
    case AsmToken::Identifier:
      Out->os() << "identifier: " << Lexer.getTok().getString();
      break;
    case AsmToken::Integer:
      Out->os() << "int: " << Lexer.getTok().getString();
      break;
    case AsmToken::Real:
      Out->os() << "real: " << Lexer.getTok().getString();
      break;
    case AsmToken::Register:
      Out->os() << "register: " << Lexer.getTok().getRegVal();
      break;
    case AsmToken::String:
      Out->os() << "string: " << Lexer.getTok().getString();
      break;

    case AsmToken::Amp:            Out->os() << "Amp"; break;
    case AsmToken::AmpAmp:         Out->os() << "AmpAmp"; break;
    case AsmToken::At:             Out->os() << "At"; break;
    case AsmToken::Caret:          Out->os() << "Caret"; break;
    case AsmToken::Colon:          Out->os() << "Colon"; break;
    case AsmToken::Comma:          Out->os() << "Comma"; break;
    case AsmToken::Dollar:         Out->os() << "Dollar"; break;
    case AsmToken::Dot:            Out->os() << "Dot"; break;
    case AsmToken::EndOfStatement: Out->os() << "EndOfStatement"; break;
    case AsmToken::Eof:            Out->os() << "Eof"; break;
    case AsmToken::Equal:          Out->os() << "Equal"; break;
    case AsmToken::EqualEqual:     Out->os() << "EqualEqual"; break;
    case AsmToken::Exclaim:        Out->os() << "Exclaim"; break;
    case AsmToken::ExclaimEqual:   Out->os() << "ExclaimEqual"; break;
    case AsmToken::Greater:        Out->os() << "Greater"; break;
    case AsmToken::GreaterEqual:   Out->os() << "GreaterEqual"; break;
    case AsmToken::GreaterGreater: Out->os() << "GreaterGreater"; break;
    case AsmToken::Hash:           Out->os() << "Hash"; break;
    case AsmToken::LBrac:          Out->os() << "LBrac"; break;
    case AsmToken::LCurly:         Out->os() << "LCurly"; break;
    case AsmToken::LParen:         Out->os() << "LParen"; break;
    case AsmToken::Less:           Out->os() << "Less"; break;
    case AsmToken::LessEqual:      Out->os() << "LessEqual"; break;
    case AsmToken::LessGreater:    Out->os() << "LessGreater"; break;
    case AsmToken::LessLess:       Out->os() << "LessLess"; break;
    case AsmToken::Minus:          Out->os() << "Minus"; break;
    case AsmToken::Percent:        Out->os() << "Percent"; break;
    case AsmToken::Pipe:           Out->os() << "Pipe"; break;
    case AsmToken::PipePipe:       Out->os() << "PipePipe"; break;
    case AsmToken::Plus:           Out->os() << "Plus"; break;
    case AsmToken::RBrac:          Out->os() << "RBrac"; break;
    case AsmToken::RCurly:         Out->os() << "RCurly"; break;
    case AsmToken::RParen:         Out->os() << "RParen"; break;
    case AsmToken::Slash:          Out->os() << "Slash"; break;
    case AsmToken::Star:           Out->os() << "Star"; break;
    case AsmToken::Tilde:          Out->os() << "Tilde"; break;
    }

    // Print the token string.
    Out->os() << " (\"";
    Out->os().write_escaped(Tok.getString());
    Out->os() << "\")\n";
  }

  // Keep output if no errors.
  if (Error == 0) Out->keep();

  return Error;
}

static int AssembleInput(const char *ProgName) {
  const Target *TheTarget = GetTarget(ProgName);
  if (!TheTarget)
    return 1;

  OwningPtr<MemoryBuffer> BufferPtr;
  if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFilename, BufferPtr)) {
    errs() << ProgName << ": " << ec.message() << '\n';
    return 1;
  }
  MemoryBuffer *Buffer = BufferPtr.take();

  SourceMgr SrcMgr;

  // Tell SrcMgr about this buffer, which is what the parser will pick up.
  SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());

  // Record the location of the include directories so that the lexer can find
  // it later.
  SrcMgr.setIncludeDirs(IncludeDirs);


  llvm::OwningPtr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(TripleName));
  assert(MAI && "Unable to create target asm info!");

  llvm::OwningPtr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
  assert(MRI && "Unable to create target register info!");

  // Package up features to be passed to target/subtarget
  std::string FeaturesStr;

  // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
  OwningPtr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
  MCContext Ctx(*MAI, *MRI, MOFI.get());
  MOFI->InitMCObjectFileInfo(TripleName, RelocModel, CMModel, Ctx);

  if (SaveTempLabels)
    Ctx.setAllowTemporaryLabels(false);

  OwningPtr<tool_output_file> Out(GetOutputStream());
  if (!Out)
    return 1;

  formatted_raw_ostream FOS(Out->os());
  OwningPtr<MCStreamer> Str;

  OwningPtr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
  OwningPtr<MCSubtargetInfo>
    STI(TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));

  // FIXME: There is a bit of code duplication with addPassesToEmitFile.
  if (FileType == OFT_AssemblyFile) {
    MCInstPrinter *IP =
      TheTarget->createMCInstPrinter(OutputAsmVariant, *MAI);
    MCCodeEmitter *CE = 0;
    MCAsmBackend *MAB = 0;
    if (ShowEncoding) {
      CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
      MAB = TheTarget->createMCAsmBackend(TripleName);
    }
    Str.reset(TheTarget->createAsmStreamer(Ctx, FOS, /*asmverbose*/true,
                                           /*useLoc*/ true,
                                           /*useCFI*/ true, IP, CE, MAB,
                                           ShowInst));
  } else if (FileType == OFT_Null) {
    Str.reset(createNullStreamer(Ctx));
  } else {
    assert(FileType == OFT_ObjectFile && "Invalid file type!");
    MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
    MCAsmBackend *MAB = TheTarget->createMCAsmBackend(TripleName);
    Str.reset(TheTarget->createMCObjectStreamer(TripleName, Ctx, *MAB,
                                                FOS, CE, RelaxAll,
                                                NoExecStack));
  }

  if (EnableLogging) {
    Str.reset(createLoggingStreamer(Str.take(), errs()));
  }

  OwningPtr<MCAsmParser> Parser(createMCAsmParser(*TheTarget, SrcMgr, Ctx,
                                                   *Str.get(), *MAI));
  OwningPtr<MCTargetAsmParser> TAP(TheTarget->createMCAsmParser(*STI, *Parser));
  if (!TAP) {
    errs() << ProgName
           << ": error: this target does not support assembly parsing.\n";
    return 1;
  }

  Parser->setShowParsedOperands(ShowInstOperands);
  Parser->setTargetParser(*TAP.get());

  int Res = Parser->Run(NoInitialTextSection);

  // Keep output if no errors.
  if (Res == 0) Out->keep();

  return Res;
}

static int DisassembleInput(const char *ProgName, bool Enhanced) {
  const Target *TheTarget = GetTarget(ProgName);
  if (!TheTarget)
    return 0;

  OwningPtr<MemoryBuffer> Buffer;
  if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFilename, Buffer)) {
    errs() << ProgName << ": " << ec.message() << '\n';
    return 1;
  }

  OwningPtr<tool_output_file> Out(GetOutputStream());
  if (!Out)
    return 1;

  int Res;
  if (Enhanced) {
    Res =
      Disassembler::disassembleEnhanced(TripleName, *Buffer.take(), Out->os());
  } else {
    Res = Disassembler::disassemble(*TheTarget, TripleName,
                                    *Buffer.take(), Out->os());
  }

  // Keep output if no errors.
  if (Res == 0) Out->keep();

  return Res;
}


int main(int argc, char **argv) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);
  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.

  // Initialize targets and assembly printers/parsers.
  llvm::InitializeAllTargetInfos();
  llvm::InitializeAllTargetMCs();
  llvm::InitializeAllAsmParsers();
  llvm::InitializeAllDisassemblers();

  cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n");
  TripleName = Triple::normalize(TripleName);

  switch (Action) {
  default:
  case AC_AsLex:
    return AsLexInput(argv[0]);
  case AC_Assemble:
    return AssembleInput(argv[0]);
  case AC_Disassemble:
    return DisassembleInput(argv[0], false);
  case AC_EDisassemble:
    return DisassembleInput(argv[0], true);
  }

  return 0;
}