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/Bitcode/BitcodeReader.h"
17 #include "llvm/Bitcode/BitcodeWriter.h"
18 #include "llvm/IRReader/IRReader.h"
19 #include "llvm/Support/CommandLine.h"
20 #include "llvm/Support/FileSystem.h"
21 
22 using namespace llvm;
23 
24 static cl::opt<bool>
25     BinaryCat("b", cl::desc("Whether to perform binary concatenation"));
26 
27 static cl::opt<std::string> OutputFilename("o", cl::Required,
28                                            cl::desc("Output filename"),
29                                            cl::value_desc("filename"));
30 
31 static cl::list<std::string> InputFilenames(cl::Positional, cl::ZeroOrMore,
32                                             cl::desc("<input  files>"));
33 
34 int main(int argc, char **argv) {
35   cl::ParseCommandLineOptions(argc, argv, "Module concatenation");
36 
37   ExitOnError ExitOnErr("llvm-cat: ");
38   LLVMContext Context;
39 
40   SmallVector<char, 0> Buffer;
41   BitcodeWriter Writer(Buffer);
42   if (BinaryCat) {
43     for (std::string InputFilename : InputFilenames) {
44       std::unique_ptr<MemoryBuffer> MB = ExitOnErr(
45           errorOrToExpected(MemoryBuffer::getFileOrSTDIN(InputFilename)));
46       std::vector<BitcodeModule> Mods = ExitOnErr(getBitcodeModuleList(*MB));
47       for (auto &BitcodeMod : Mods)
48         Buffer.insert(Buffer.end(), BitcodeMod.getBuffer().begin(),
49                       BitcodeMod.getBuffer().end());
50     }
51   } else {
52     for (std::string InputFilename : InputFilenames) {
53       SMDiagnostic Err;
54       std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context);
55       if (!M) {
56         Err.print(argv[0], errs());
57         return 1;
58       }
59       Writer.writeModule(M.get());
60     }
61   }
62 
63   std::error_code EC;
64   raw_fd_ostream OS(OutputFilename, EC, sys::fs::OpenFlags::F_None);
65   if (EC) {
66     llvm::errs() << argv[0] << ": cannot open " << OutputFilename
67                  << " for writing: " << EC.message();
68     return 1;
69   }
70 
71   OS.write(Buffer.data(), Buffer.size());
72   return 0;
73 }
74