llvm-project

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//===- llvm-cat.cpp - LLVM module concatenation utility -------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This program is for testing features that rely on multi-module bitcode files.
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// It takes a list of input modules and uses them to create a multi-module
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// bitcode file.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/Bitcode/BitcodeReader.h"
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#include "llvm/Bitcode/BitcodeWriter.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IRReader/IRReader.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Error.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/SourceMgr.h"
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#include "llvm/Support/raw_ostream.h"
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#include <algorithm>
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#include <memory>
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#include <string>
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#include <system_error>
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#include <vector>
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using namespace llvm;
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cl::OptionCategory CatCategory("llvm-cat Options");
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static cl::opt<bool>
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    BinaryCat("b", cl::desc("Whether to perform binary concatenation"),
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              cl::cat(CatCategory));
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static cl::opt<std::string> OutputFilename("o", cl::Required,
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                                           cl::desc("Output filename"),
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                                           cl::value_desc("filename"),
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                                           cl::cat(CatCategory));
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static cl::list<std::string> InputFilenames(cl::Positional,
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                                            cl::desc("<input  files>"),
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                                            cl::cat(CatCategory));
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int main(int argc, char **argv) {
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  cl::HideUnrelatedOptions(CatCategory);
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  cl::ParseCommandLineOptions(argc, argv, "Module concatenation");
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  ExitOnError ExitOnErr("llvm-cat: ");
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  LLVMContext Context;
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  SmallVector<char, 0> Buffer;
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  BitcodeWriter Writer(Buffer);
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  if (BinaryCat) {
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    for (const auto &InputFilename : InputFilenames) {
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      std::unique_ptr<MemoryBuffer> MB = ExitOnErr(
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          errorOrToExpected(MemoryBuffer::getFileOrSTDIN(InputFilename)));
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      std::vector<BitcodeModule> Mods = ExitOnErr(getBitcodeModuleList(*MB));
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      for (auto &BitcodeMod : Mods) {
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        llvm::append_range(Buffer, BitcodeMod.getBuffer());
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        Writer.copyStrtab(BitcodeMod.getStrtab());
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      }
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    }
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  } else {
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    // The string table does not own strings added to it, some of which are
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    // owned by the modules; keep them alive until we write the string table.
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    std::vector<std::unique_ptr<Module>> OwnedMods;
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    for (const auto &InputFilename : InputFilenames) {
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      SMDiagnostic Err;
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      std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context);
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      if (!M) {
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        Err.print(argv[0], errs());
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        return 1;
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      }
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      Writer.writeModule(*M);
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      OwnedMods.push_back(std::move(M));
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    }
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    Writer.writeStrtab();
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  }
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  std::error_code EC;
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  raw_fd_ostream OS(OutputFilename, EC, sys::fs::OpenFlags::OF_None);
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  if (EC) {
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    errs() << argv[0] << ": cannot open " << OutputFilename << " for writing: "
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           << EC.message();
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    return 1;
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  }
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  OS.write(Buffer.data(), Buffer.size());
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  return 0;
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}
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