Commit 22af2cbe authored by Eric Astor's avatar Eric Astor
Browse files

[ms] [llvm-ml] Add placeholder for llvm-ml, based on llvm-mc 

Summary:
As discussed on the mailing list, I plan to introduce an ml-compatible MASM assembler as part of providing more of the Windows build tools. This will be similar to llvm-mc, but with different command-line parameters.

This placeholder is purely a stripped-down version of llvm-mc; we'll eventually add support for the Microsoft-style command-line flags, and back it with a MASM parser.

Reviewers: rnk, thakis

Reviewed By: thakis

Subscribers: merge_guards_bot, mgorny, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72679
parent 510758da

llvm/test/CMakeLists.txt

+1 −0
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@@ -80,6 +80,7 @@ set(LLVM_TEST_DEPENDS 
          llvm-lto2

          llvm-mc

          llvm-mca

          llvm-ml

          llvm-modextract

          llvm-mt

          llvm-nm

llvm/test/tools/llvm-ml/basic.test

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# RUN: not llvm-ml %t.blah -o /dev/null 2>&1 | FileCheck --check-prefix=ENOENT %s



# ENOENT: {{.*}}.blah: {{[Nn]}}o such file or directory

llvm/test/tools/llvm-ml/run.test

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# RUN: llvm-ml --help | FileCheck %s



# CHECK: USAGE: llvm-ml
 
 No newline at end of file

llvm/tools/llvm-ml/CMakeLists.txt

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set(LLVM_LINK_COMPONENTS

  AllTargetsAsmPrinters

  AllTargetsAsmParsers

  AllTargetsDescs

  AllTargetsDisassemblers

  AllTargetsInfos

  MC

  MCParser

  Support

  )



add_llvm_tool(llvm-ml

  llvm-ml.cpp

  Disassembler.cpp

  )

llvm/tools/llvm-ml/Disassembler.cpp

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//===- 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/Support/MemoryBuffer.h"

#include "llvm/Support/SourceMgr.h"

#include "llvm/Support/TargetRegistry.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 &Triple,

                              MCSubtargetInfo &STI, MCStreamer &Streamer,

                              MemoryBuffer &Buffer, SourceMgr &SM,

                              raw_ostream &Out) {

  std::unique_ptr<const MCRegisterInfo> MRI(T.createMCRegInfo(Triple));

  if (!MRI) {

    errs() << "error: no register info for target " << Triple << "\n";

    return -1;

  }



  MCTargetOptions MCOptions;

  std::unique_ptr<const MCAsmInfo> MAI(

      T.createMCAsmInfo(*MRI, Triple, MCOptions));

  if (!MAI) {

    errs() << "error: no assembly info for target " << Triple << "\n";

    return -1;

  }



  // Set up the MCContext for creating symbols and MCExpr's.

  MCContext Ctx(MAI.get(), MRI.get(), nullptr);



  std::unique_ptr<const MCDisassembler> DisAsm(

      T.createMCDisassembler(STI, Ctx));

  if (!DisAsm) {

    errs() << "error: no disassembler for target " << Triple << "\n";

    return -1;

  }



  // Set up initial section manually here

  Streamer.InitSections(false);



  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;

}