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/PrettyStackTrace.h"
  23 #include "llvm/Support/ToolOutputFile.h"
  24 #include "llvm/Support/SystemUtils.h"
  25 #include "llvm/Support/IRReader.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 OutputAssembly("S",
  44          cl::desc("Write output as LLVM assembly"), cl::Hidden);
  45
  46 static cl::opt<bool>
  47 Verbose("v", cl::desc("Print information about actions taken"));
  48
  49 static cl::opt<bool>
  50 DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
  51
  52 // LoadFile - Read the specified bitcode file in and return it.  This routine
  53 // searches the link path for the specified file to try to find it...
  54 //
  55 static inline std::auto_ptr<Module> LoadFile(const char *argv0,
  56                                              const std::string &FN,
  57                                              LLVMContext& Context) {
  58   sys::Path Filename;
  59   if (!Filename.set(FN)) {
  60     errs() << "Invalid file name: '" << FN << "'\n";
  61     return std::auto_ptr<Module>();
  62   }
  63
  64   SMDiagnostic Err;
  65   if (Verbose) errs() << "Loading '" << Filename.c_str() << "'\n";
  66   Module* Result = 0;
  67
  68   const std::string &FNStr = Filename.str();
  69   Result = ParseIRFile(FNStr, Err, Context);
  70   if (Result) return std::auto_ptr<Module>(Result);   // Load successful!
  71
  72   Err.Print(argv0, errs());
  73   return std::auto_ptr<Module>();
  74 }
  75
  76 int main(int argc, char **argv) {
  77   // Print a stack trace if we signal out.
  78   sys::PrintStackTraceOnErrorSignal();
  79   PrettyStackTraceProgram X(argc, argv);
  80
  81   LLVMContext &Context = getGlobalContext();
  82   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  83   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
  84
  85   unsigned BaseArg = 0;
  86   std::string ErrorMessage;
  87
  88   std::auto_ptr<Module> Composite(LoadFile(argv[0],
  89                                            InputFilenames[BaseArg], Context));
  90   if (Composite.get() == 0) {
  91     errs() << argv[0] << ": error loading file '"
  92            << InputFilenames[BaseArg] << "'\n";
  93     return 1;
  94   }
  95
  96   for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
  97     std::auto_ptr<Module> M(LoadFile(argv[0],
  98                                      InputFilenames[i], Context));
  99     if (M.get() == 0) {
 100       errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
 101       return 1;
 102     }
 103
 104     if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
 105
 106     if (Linker::LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
 107       errs() << argv[0] << ": link error in '" << InputFilenames[i]
 108              << "': " << ErrorMessage << "\n";
 109       return 1;
 110     }
 111   }
 112
 113   // TODO: Iterate over the -l list and link in any modules containing
 114   // global symbols that have not been resolved so far.
 115
 116   if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
 117
 118   std::string ErrorInfo;
 119   tool_output_file Out(OutputFilename.c_str(), ErrorInfo,
 120                        raw_fd_ostream::F_Binary);
 121   if (!ErrorInfo.empty()) {
 122     errs() << ErrorInfo << '\n';
 123     return 1;
 124   }
 125
 126   if (verifyModule(*Composite)) {
 127     errs() << argv[0] << ": linked module is broken!\n";
 128     return 1;
 129   }
 130
 131   if (Verbose) errs() << "Writing bitcode...\n";
 132   if (OutputAssembly) {
 133     Out.os() << *Composite;
 134   } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
 135     WriteBitcodeToFile(Composite.get(), Out.os());
 136
 137   // Declare success.
 138   Out.keep();
 139
 140   return 0;
 141 }