tools/llvm-as/llvm-as.cpp

   1 //===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===//
   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-as --help         - Output information about command line switches
  12 //   llvm-as [options]      - Read LLVM asm from stdin, write bitcode to stdout
  13 //   llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode
  14 //                            to the x.bc file.
  15 //
  16 //===----------------------------------------------------------------------===//
  17
  18 #include "llvm/LLVMContext.h"
  19 #include "llvm/Module.h"
  20 #include "llvm/Assembly/Parser.h"
  21 #include "llvm/Analysis/Verifier.h"
  22 #include "llvm/Bitcode/ReaderWriter.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/ManagedStatic.h"
  25 #include "llvm/Support/PrettyStackTrace.h"
  26 #include "llvm/Support/SourceMgr.h"
  27 #include "llvm/Support/SystemUtils.h"
  28 #include "llvm/Support/ToolOutputFile.h"
  29 #include "llvm/Support/Signals.h"
  30 #include <memory>
  31 using namespace llvm;
  32
  33 static cl::opt<std::string>
  34 InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
  35
  36 static cl::opt<std::string>
  37 OutputFilename("o", cl::desc("Override output filename"),
  38                cl::value_desc("filename"));
  39
  40 static cl::opt<bool>
  41 Force("f", cl::desc("Enable binary output on terminals"));
  42
  43 static cl::opt<bool>
  44 DisableOutput("disable-output", cl::desc("Disable output"), cl::init(false));
  45
  46 static cl::opt<bool>
  47 DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
  48
  49 static cl::opt<bool>
  50 DisableVerify("disable-verify", cl::Hidden,
  51               cl::desc("Do not run verifier on input LLVM (dangerous!)"));
  52
  53 static void WriteOutputFile(const Module *M) {
  54   // Infer the output filename if needed.
  55   if (OutputFilename.empty()) {
  56     if (InputFilename == "-") {
  57       OutputFilename = "-";
  58     } else {
  59       std::string IFN = InputFilename;
  60       int Len = IFN.length();
  61       if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
  62         // Source ends in .ll
  63         OutputFilename = std::string(IFN.begin(), IFN.end()-3);
  64       } else {
  65         OutputFilename = IFN;   // Append a .bc to it
  66       }
  67       OutputFilename += ".bc";
  68     }
  69   }
  70
  71   std::string ErrorInfo;
  72   OwningPtr<tool_output_file> Out
  73   (new tool_output_file(OutputFilename.c_str(), ErrorInfo,
  74                         raw_fd_ostream::F_Binary));
  75   if (!ErrorInfo.empty()) {
  76     errs() << ErrorInfo << '\n';
  77     exit(1);
  78   }
  79
  80   if (Force || !CheckBitcodeOutputToConsole(Out->os(), true))
  81     WriteBitcodeToFile(M, Out->os());
  82
  83   // Declare success.
  84   Out->keep();
  85 }
  86
  87 int main(int argc, char **argv) {
  88   // Print a stack trace if we signal out.
  89   sys::PrintStackTraceOnErrorSignal();
  90   PrettyStackTraceProgram X(argc, argv);
  91   LLVMContext &Context = getGlobalContext();
  92   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  93   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
  94
  95   // Parse the file now...
  96   SMDiagnostic Err;
  97   std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename, Err, Context));
  98   if (M.get() == 0) {
  99     Err.Print(argv[0], errs());
 100     return 1;
 101   }
 102
 103   if (!DisableVerify) {
 104     std::string Err;
 105     if (verifyModule(*M.get(), ReturnStatusAction, &Err)) {
 106       errs() << argv[0]
 107              << ": assembly parsed, but does not verify as correct!\n";
 108       errs() << Err;
 109       return 1;
 110     }
 111   }
 112
 113   if (DumpAsm) errs() << "Here's the assembly:\n" << *M.get();
 114
 115   if (!DisableOutput)
 116     WriteOutputFile(M.get());
 117
 118   return 0;
 119 }