tools/llvm-cat/llvm-cat.cpp

   1 //===- llvm-cat.cpp - LLVM module concatenation utility -------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This program is for testing features that rely on multi-module bitcode files.
  11 // It takes a list of input modules and uses them to create a multi-module
  12 // bitcode file.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/ADT/SmallVector.h"
  17 #include "llvm/Bitcode/BitcodeReader.h"
  18 #include "llvm/Bitcode/BitcodeWriter.h"
  19 #include "llvm/IR/LLVMContext.h"
  20 #include "llvm/IR/Module.h"
  21 #include "llvm/IRReader/IRReader.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include "llvm/Support/Error.h"
  24 #include "llvm/Support/FileSystem.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/SourceMgr.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include <algorithm>
  29 #include <memory>
  30 #include <string>
  31 #include <system_error>
  32 #include <vector>
  33
  34 using namespace llvm;
  35
  36 static cl::opt<bool>
  37     BinaryCat("b", cl::desc("Whether to perform binary concatenation"));
  38
  39 static cl::opt<std::string> OutputFilename("o", cl::Required,
  40                                            cl::desc("Output filename"),
  41                                            cl::value_desc("filename"));
  42
  43 static cl::list<std::string> InputFilenames(cl::Positional, cl::ZeroOrMore,
  44                                             cl::desc("<input  files>"));
  45
  46 int main(int argc, char **argv) {
  47   cl::ParseCommandLineOptions(argc, argv, "Module concatenation");
  48
  49   ExitOnError ExitOnErr("llvm-cat: ");
  50   LLVMContext Context;
  51
  52   SmallVector<char, 0> Buffer;
  53   BitcodeWriter Writer(Buffer);
  54   if (BinaryCat) {
  55     for (const auto &InputFilename : InputFilenames) {
  56       std::unique_ptr<MemoryBuffer> MB = ExitOnErr(
  57           errorOrToExpected(MemoryBuffer::getFileOrSTDIN(InputFilename)));
  58       std::vector<BitcodeModule> Mods = ExitOnErr(getBitcodeModuleList(*MB));
  59       for (auto &BitcodeMod : Mods) {
  60         Buffer.insert(Buffer.end(), BitcodeMod.getBuffer().begin(),
  61                       BitcodeMod.getBuffer().end());
  62         Writer.copyStrtab(BitcodeMod.getStrtab());
  63       }
  64     }
  65   } else {
  66     // The string table does not own strings added to it, some of which are
  67     // owned by the modules; keep them alive until we write the string table.
  68     std::vector<std::unique_ptr<Module>> OwnedMods;
  69     for (const auto &InputFilename : InputFilenames) {
  70       SMDiagnostic Err;
  71       std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context);
  72       if (!M) {
  73         Err.print(argv[0], errs());
  74         return 1;
  75       }
  76       Writer.writeModule(*M);
  77       OwnedMods.push_back(std::move(M));
  78     }
  79     Writer.writeStrtab();
  80   }
  81
  82   std::error_code EC;
  83   raw_fd_ostream OS(OutputFilename, EC, sys::fs::OpenFlags::F_None);
  84   if (EC) {
  85     errs() << argv[0] << ": cannot open " << OutputFilename << " for writing: "
  86            << EC.message();
  87     return 1;
  88   }
  89
  90   OS.write(Buffer.data(), Buffer.size());
  91   return 0;
  92 }