tools/llvm-link/llvm-link.cpp

   1 //===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
   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 utility may be invoked in the following manner:
  11 //  llvm-link a.bc b.bc c.bc -o x.bc
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Linker.h"
  16 #include "llvm/Module.h"
  17 #include "llvm/Analysis/Verifier.h"
  18 #include "llvm/Bitcode/ReaderWriter.h"
  19 #include "llvm/Support/CommandLine.h"
  20 #include "llvm/Support/ManagedStatic.h"
  21 #include "llvm/Support/MemoryBuffer.h"
  22 #include "llvm/Support/PrettyStackTrace.h"
  23 #include "llvm/Support/Streams.h"
  24 #include "llvm/System/Signals.h"
  25 #include "llvm/System/Path.h"
  26 #include <fstream>
  27 #include <iostream>
  28 #include <memory>
  29 using namespace llvm;
  30
  31 static cl::list<std::string>
  32 InputFilenames(cl::Positional, cl::OneOrMore,
  33                cl::desc("<input bitcode files>"));
  34
  35 static cl::opt<std::string>
  36 OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
  37                cl::value_desc("filename"));
  38
  39 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
  40
  41 static cl::opt<bool>
  42 Verbose("v", cl::desc("Print information about actions taken"));
  43
  44 static cl::opt<bool>
  45 DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
  46
  47 // LoadFile - Read the specified bitcode file in and return it.  This routine
  48 // searches the link path for the specified file to try to find it...
  49 //
  50 static inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
  51   sys::Path Filename;
  52   if (!Filename.set(FN)) {
  53     cerr << "Invalid file name: '" << FN << "'\n";
  54     return std::auto_ptr<Module>();
  55   }
  56
  57   std::string ErrorMessage;
  58   if (Filename.exists()) {
  59     if (Verbose) cerr << "Loading '" << Filename.c_str() << "'\n";
  60     Module* Result = 0;
  61
  62     const std::string &FNStr = Filename.toString();
  63     if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(FNStr,
  64                                                             &ErrorMessage)) {
  65       Result = ParseBitcodeFile(Buffer, &ErrorMessage);
  66       delete Buffer;
  67     }
  68     if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
  69
  70     if (Verbose) {
  71       cerr << "Error opening bitcode file: '" << Filename.c_str() << "'";
  72       if (ErrorMessage.size()) cerr << ": " << ErrorMessage;
  73       cerr << "\n";
  74     }
  75   } else {
  76     cerr << "Bitcode file: '" << Filename.c_str() << "' does not exist.\n";
  77   }
  78
  79   return std::auto_ptr<Module>();
  80 }
  81
  82 int main(int argc, char **argv) {
  83   // Print a stack trace if we signal out.
  84   sys::PrintStackTraceOnErrorSignal();
  85   PrettyStackTraceProgram X(argc, argv);
  86
  87   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  88   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
  89
  90   unsigned BaseArg = 0;
  91   std::string ErrorMessage;
  92
  93   std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg]));
  94   if (Composite.get() == 0) {
  95     cerr << argv[0] << ": error loading file '"
  96          << InputFilenames[BaseArg] << "'\n";
  97     return 1;
  98   }
  99
 100   for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
 101     std::auto_ptr<Module> M(LoadFile(InputFilenames[i]));
 102     if (M.get() == 0) {
 103       cerr << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
 104       return 1;
 105     }
 106
 107     if (Verbose) cerr << "Linking in '" << InputFilenames[i] << "'\n";
 108
 109     if (Linker::LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
 110       cerr << argv[0] << ": link error in '" << InputFilenames[i]
 111            << "': " << ErrorMessage << "\n";
 112       return 1;
 113     }
 114   }
 115
 116   // TODO: Iterate over the -l list and link in any modules containing
 117   // global symbols that have not been resolved so far.
 118
 119   if (DumpAsm) cerr << "Here's the assembly:\n" << *Composite.get();
 120
 121   // FIXME: cout is not binary!
 122   std::ostream *Out = &std::cout;  // Default to printing to stdout...
 123   if (OutputFilename != "-") {
 124     if (!Force && std::ifstream(OutputFilename.c_str())) {
 125       // If force is not specified, make sure not to overwrite a file!
 126       cerr << argv[0] << ": error opening '" << OutputFilename
 127            << "': file exists!\n"
 128            << "Use -f command line argument to force output\n";
 129       return 1;
 130     }
 131     std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 132                                  std::ios::binary;
 133     Out = new std::ofstream(OutputFilename.c_str(), io_mode);
 134     if (!Out->good()) {
 135       cerr << argv[0] << ": error opening '" << OutputFilename << "'!\n";
 136       return 1;
 137     }
 138
 139     // Make sure that the Out file gets unlinked from the disk if we get a
 140     // SIGINT
 141     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 142   }
 143
 144   if (verifyModule(*Composite.get())) {
 145     cerr << argv[0] << ": linked module is broken!\n";
 146     return 1;
 147   }
 148
 149   if (Verbose) cerr << "Writing bitcode...\n";
 150   WriteBitcodeToFile(Composite.get(), *Out);
 151
 152   if (Out != &std::cout) delete Out;
 153   return 0;
 154 }