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/LLVMContext.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/Analysis/Verifier.h"
  19 #include "llvm/Bitcode/ReaderWriter.h"
  20 #include "llvm/Support/CommandLine.h"
  21 #include "llvm/Support/ManagedStatic.h"
  22 #include "llvm/Support/MemoryBuffer.h"
  23 #include "llvm/Support/PrettyStackTrace.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include "llvm/Support/SystemUtils.h"
  26 #include "llvm/System/Signals.h"
  27 #include "llvm/System/Path.h"
  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>
  40 Force("f", cl::desc("Enable binary output on terminals"));
  41
  42 static cl::opt<bool>
  43 Verbose("v", cl::desc("Print information about actions taken"));
  44
  45 static cl::opt<bool>
  46 DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
  47
  48 // LoadFile - Read the specified bitcode file in and return it.  This routine
  49 // searches the link path for the specified file to try to find it...
  50 //
  51 static inline std::auto_ptr<Module> LoadFile(const std::string &FN,
  52                                              LLVMContext& Context) {
  53   sys::Path Filename;
  54   if (!Filename.set(FN)) {
  55     errs() << "Invalid file name: '" << FN << "'\n";
  56     return std::auto_ptr<Module>();
  57   }
  58
  59   std::string ErrorMessage;
  60   if (Filename.exists()) {
  61     if (Verbose) errs() << "Loading '" << Filename.c_str() << "'\n";
  62     Module* Result = 0;
  63
  64     const std::string &FNStr = Filename.str();
  65     if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(FNStr,
  66                                                             &ErrorMessage)) {
  67       Result = ParseBitcodeFile(Buffer, Context, &ErrorMessage);
  68       delete Buffer;
  69     }
  70     if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
  71
  72     if (Verbose) {
  73       errs() << "Error opening bitcode file: '" << Filename.c_str() << "'";
  74       if (ErrorMessage.size()) errs() << ": " << ErrorMessage;
  75       errs() << "\n";
  76     }
  77   } else {
  78     errs() << "Bitcode file: '" << Filename.c_str() << "' does not exist.\n";
  79   }
  80
  81   return std::auto_ptr<Module>();
  82 }
  83
  84 int main(int argc, char **argv) {
  85   // Print a stack trace if we signal out.
  86   sys::PrintStackTraceOnErrorSignal();
  87   PrettyStackTraceProgram X(argc, argv);
  88
  89   LLVMContext &Context = getGlobalContext();
  90   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  91   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
  92
  93   unsigned BaseArg = 0;
  94   std::string ErrorMessage;
  95
  96   std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg], Context));
  97   if (Composite.get() == 0) {
  98     errs() << argv[0] << ": error loading file '"
  99            << InputFilenames[BaseArg] << "'\n";
 100     return 1;
 101   }
 102
 103   for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
 104     std::auto_ptr<Module> M(LoadFile(InputFilenames[i], Context));
 105     if (M.get() == 0) {
 106       errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
 107       return 1;
 108     }
 109
 110     if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
 111
 112     if (Linker::LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
 113       errs() << argv[0] << ": link error in '" << InputFilenames[i]
 114              << "': " << ErrorMessage << "\n";
 115       return 1;
 116     }
 117   }
 118
 119   // TODO: Iterate over the -l list and link in any modules containing
 120   // global symbols that have not been resolved so far.
 121
 122   if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite.get();
 123
 124   std::string ErrorInfo;
 125   std::auto_ptr<raw_ostream>
 126   Out(new raw_fd_ostream(OutputFilename.c_str(), ErrorInfo,
 127                          raw_fd_ostream::F_Binary));
 128   if (!ErrorInfo.empty()) {
 129     errs() << ErrorInfo << '\n';
 130     return 1;
 131   }
 132
 133     // Make sure that the Out file gets unlinked from the disk if we get a
 134     // SIGINT
 135   if (OutputFilename != "-")
 136     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 137
 138   if (verifyModule(*Composite.get())) {
 139     errs() << argv[0] << ": linked module is broken!\n";
 140     return 1;
 141   }
 142
 143   if (Verbose) errs() << "Writing bitcode...\n";
 144   if (Force || !CheckBitcodeOutputToConsole(*Out, true))
 145     WriteBitcodeToFile(Composite.get(), *Out);
 146
 147   return 0;
 148 }