lld/COFF/LTO.h

   1 //===- LTO.h ----------------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file provides a way to combine bitcode files into one COFF
  10 // file by compiling them using LLVM.
  11 //
  12 // If LTO is in use, your input files are not in regular COFF files
  13 // but instead LLVM bitcode files. In that case, the linker has to
  14 // convert bitcode files into the native format so that we can create
  15 // a COFF file that contains native code. This file provides that
  16 // functionality.
  17 //
  18 //===----------------------------------------------------------------------===//
  19
  20 #ifndef LLD_COFF_LTO_H
  21 #define LLD_COFF_LTO_H
  22
  23 #include "lld/Common/LLVM.h"
  24 #include "llvm/ADT/DenseSet.h"
  25 #include "llvm/ADT/SmallString.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include <memory>
  28 #include <vector>
  29
  30 namespace llvm::lto {
  31 struct Config;
  32 class LTO;
  33 }
  34
  35 namespace lld::coff {
  36
  37 class BitcodeFile;
  38 class InputFile;
  39 class COFFLinkerContext;
  40
  41 class BitcodeCompiler {
  42 public:
  43   BitcodeCompiler(COFFLinkerContext &ctx);
  44   ~BitcodeCompiler();
  45
  46   void add(BitcodeFile &f);
  47   std::vector<InputFile *> compile();
  48
  49 private:
  50   std::unique_ptr<llvm::lto::LTO> ltoObj;
  51   std::vector<std::pair<std::string, SmallString<0>>> buf;
  52   std::vector<std::unique_ptr<MemoryBuffer>> files;
  53   std::vector<std::string> file_names;
  54   std::unique_ptr<llvm::raw_fd_ostream> indexFile;
  55   llvm::DenseSet<StringRef> thinIndices;
  56
  57   std::string getThinLTOOutputFile(StringRef path);
  58   llvm::lto::Config createConfig();
  59
  60   COFFLinkerContext &ctx;
  61 };
  62 }
  63
  64 #endif