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/AsmParser/Parser.h"
  19 #include "llvm/Bitcode/BitcodeWriter.h"
  20 #include "llvm/IR/LLVMContext.h"
  21 #include "llvm/IR/Module.h"
  22 #include "llvm/IR/Verifier.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/FileSystem.h"
  25 #include "llvm/Support/ManagedStatic.h"
  26 #include "llvm/Support/PrettyStackTrace.h"
  27 #include "llvm/Support/Signals.h"
  28 #include "llvm/Support/SourceMgr.h"
  29 #include "llvm/Support/SystemUtils.h"
  30 #include "llvm/Support/ToolOutputFile.h"
  31 #include <memory>
  32 using namespace llvm;
  33
  34 static cl::opt<std::string> InputFilename(cl::Positional,
  35                                           cl::desc("<input .llvm file>"),
  36                                           cl::init("-"));
  37
  38 static cl::opt<std::string> OutputFilename("o",
  39                                            cl::desc("Override output filename"),
  40                                            cl::value_desc("filename"));
  41
  42 static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"));
  43
  44 static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"),
  45                                    cl::init(false));
  46
  47 static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
  48                                     cl::init(false));
  49
  50 static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"),
  51                              cl::Hidden);
  52
  53 static cl::opt<bool>
  54     DisableVerify("disable-verify", cl::Hidden,
  55                   cl::desc("Do not run verifier on input LLVM (dangerous!)"));
  56
  57 static cl::opt<bool> PreserveBitcodeUseListOrder(
  58     "preserve-bc-uselistorder",
  59     cl::desc("Preserve use-list order when writing LLVM bitcode."),
  60     cl::init(true), cl::Hidden);
  61
  62 static void WriteOutputFile(const Module *M) {
  63   // Infer the output filename if needed.
  64   if (OutputFilename.empty()) {
  65     if (InputFilename == "-") {
  66       OutputFilename = "-";
  67     } else {
  68       StringRef IFN = InputFilename;
  69       OutputFilename = (IFN.endswith(".ll") ? IFN.drop_back(3) : IFN).str();
  70       OutputFilename += ".bc";
  71     }
  72   }
  73
  74   std::error_code EC;
  75   std::unique_ptr<tool_output_file> Out(
  76       new tool_output_file(OutputFilename, EC, sys::fs::F_None));
  77   if (EC) {
  78     errs() << EC.message() << '\n';
  79     exit(1);
  80   }
  81
  82   if (Force || !CheckBitcodeOutputToConsole(Out->os(), true))
  83     WriteBitcodeToFile(M, Out->os(), PreserveBitcodeUseListOrder, nullptr,
  84                        EmitModuleHash);
  85
  86   // Declare success.
  87   Out->keep();
  88 }
  89
  90 int main(int argc, char **argv) {
  91   // Print a stack trace if we signal out.
  92   sys::PrintStackTraceOnErrorSignal(argv[0]);
  93   PrettyStackTraceProgram X(argc, argv);
  94   LLVMContext Context;
  95   llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
  96   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
  97
  98   // Parse the file now...
  99   SMDiagnostic Err;
 100   std::unique_ptr<Module> M = parseAssemblyFile(InputFilename, Err, Context);
 101   if (!M.get()) {
 102     Err.print(argv[0], errs());
 103     return 1;
 104   }
 105
 106   if (!DisableVerify) {
 107     std::string ErrorStr;
 108     raw_string_ostream OS(ErrorStr);
 109     if (verifyModule(*M.get(), &OS)) {
 110       errs() << argv[0]
 111              << ": assembly parsed, but does not verify as correct!\n";
 112       errs() << OS.str();
 113       return 1;
 114     }
 115   }
 116
 117   if (DumpAsm)
 118     errs() << "Here's the assembly:\n" << *M.get();
 119
 120   if (!DisableOutput)
 121     WriteOutputFile(M.get());
 122
 123   return 0;
 124 }