src/llvm/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/Linker.h"
  16 #include "llvm/Bitcode/ReaderWriter.h"
  17 #include "llvm/IR/DiagnosticInfo.h"
  18 #include "llvm/IR/DiagnosticPrinter.h"
  19 #include "llvm/IR/LLVMContext.h"
  20 #include "llvm/IR/Module.h"
  21 #include "llvm/IR/Verifier.h"
  22 #include "llvm/IRReader/IRReader.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/FileSystem.h"
  25 #include "llvm/Support/ManagedStatic.h"
  26 #include "llvm/Support/Path.h"
  27 #include "llvm/Support/PrettyStackTrace.h"
  28 #include "llvm/Support/Signals.h"
  29 #include "llvm/Support/SourceMgr.h"
  30 #include "llvm/Support/SystemUtils.h"
  31 #include "llvm/Support/ToolOutputFile.h"
  32 #include <memory>
  33 using namespace llvm;
  34
  35 static cl::list<std::string>
  36 InputFilenames(cl::Positional, cl::OneOrMore,
  37                cl::desc("<input bitcode files>"));
  38
  39 static cl::opt<std::string>
  40 OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
  41                cl::value_desc("filename"));
  42
  43 static cl::opt<bool>
  44 Force("f", cl::desc("Enable binary output on terminals"));
  45
  46 static cl::opt<bool>
  47 OutputAssembly("S",
  48          cl::desc("Write output as LLVM assembly"), cl::Hidden);
  49
  50 static cl::opt<bool>
  51 Verbose("v", cl::desc("Print information about actions taken"));
  52
  53 static cl::opt<bool>
  54 DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden);
  55
  56 static cl::opt<bool>
  57 SuppressWarnings("suppress-warnings", cl::desc("Suppress all linking warnings"),
  58                  cl::init(false));
  59
  60 // Read the specified bitcode file in and return it. This routine searches the
  61 // link path for the specified file to try to find it...
  62 //
  63 static std::unique_ptr<Module>
  64 loadFile(const char *argv0, const std::string &FN, LLVMContext &Context) {
  65   SMDiagnostic Err;
  66   if (Verbose) errs() << "Loading '" << FN << "'\n";
  67   std::unique_ptr<Module> Result = getLazyIRFileModule(FN, Err, Context);
  68   if (!Result)
  69     Err.print(argv0, errs());
  70
  71   return Result;
  72 }
  73
  74 static void diagnosticHandler(const DiagnosticInfo &DI) {
  75   unsigned Severity = DI.getSeverity();
  76   switch (Severity) {
  77   case DS_Error:
  78     errs() << "ERROR: ";
  79     break;
  80   case DS_Warning:
  81     if (SuppressWarnings)
  82       return;
  83     errs() << "WARNING: ";
  84     break;
  85   case DS_Remark:
  86   case DS_Note:
  87     llvm_unreachable("Only expecting warnings and errors");
  88   }
  89
  90   DiagnosticPrinterRawOStream DP(errs());
  91   DI.print(DP);
  92   errs() << '\n';
  93 }
  94
  95 int main(int argc, char **argv) {
  96   // Print a stack trace if we signal out.
  97   sys::PrintStackTraceOnErrorSignal();
  98   PrettyStackTraceProgram X(argc, argv);
  99
 100   LLVMContext &Context = getGlobalContext();
 101   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 102   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
 103
 104   auto Composite = make_unique<Module>("llvm-link", Context);
 105   Linker L(Composite.get(), diagnosticHandler);
 106
 107   for (unsigned i = 0; i < InputFilenames.size(); ++i) {
 108     std::unique_ptr<Module> M = loadFile(argv[0], InputFilenames[i], Context);
 109     if (!M.get()) {
 110       errs() << argv[0] << ": error loading file '" <<InputFilenames[i]<< "'\n";
 111       return 1;
 112     }
 113
 114     if (Verbose) errs() << "Linking in '" << InputFilenames[i] << "'\n";
 115
 116     if (L.linkInModule(M.get()))
 117       return 1;
 118   }
 119
 120   if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite;
 121
 122   std::error_code EC;
 123   tool_output_file Out(OutputFilename, EC, sys::fs::F_None);
 124   if (EC) {
 125     errs() << EC.message() << '\n';
 126     return 1;
 127   }
 128
 129   if (verifyModule(*Composite)) {
 130     errs() << argv[0] << ": linked module is broken!\n";
 131     return 1;
 132   }
 133
 134   if (Verbose) errs() << "Writing bitcode...\n";
 135   if (OutputAssembly) {
 136     Out.os() << *Composite;
 137   } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
 138     WriteBitcodeToFile(Composite.get(), Out.os());
 139
 140   // Declare success.
 141   Out.keep();
 142
 143   return 0;
 144 }