xref: /freebsd/contrib/llvm-project/lld/ELF/LTO.h (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
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 ELF
10 // file by compiling them using LLVM.
11 //
12 // If LTO is in use, your input files are not in regular ELF 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 // an ELF file that contains native code. This file provides that
16 // functionality.
17 //
18 //===----------------------------------------------------------------------===//
19 
20 #ifndef LLD_ELF_LTO_H
21 #define LLD_ELF_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 class LTO;
32 }
33 
34 namespace lld::elf {
35 
36 class BitcodeFile;
37 class InputFile;
38 
39 class BitcodeCompiler {
40 public:
41   BitcodeCompiler();
42   ~BitcodeCompiler();
43 
44   void add(BitcodeFile &f);
45   std::vector<InputFile *> compile();
46 
47 private:
48   std::unique_ptr<llvm::lto::LTO> ltoObj;
49   // An array of (module name, native relocatable file content) pairs.
50   SmallVector<std::pair<std::string, SmallString<0>>, 0> buf;
51   std::vector<std::unique_ptr<MemoryBuffer>> files;
52   SmallVector<std::string, 0> filenames;
53   llvm::DenseSet<StringRef> usedStartStop;
54   std::unique_ptr<llvm::raw_fd_ostream> indexFile;
55   llvm::DenseSet<StringRef> thinIndices;
56 };
57 } // namespace lld::elf
58 
59 #endif
60