llvm-as.cpp revision 263508 
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/IR/LLVMContext.h"
19#include "llvm/Analysis/Verifier.h"
20#include "llvm/Assembly/Parser.h"
21#include "llvm/Bitcode/ReaderWriter.h"
22#include "llvm/IR/Module.h"
23#include "llvm/Support/CommandLine.h"
24#include "llvm/Support/ManagedStatic.h"
25#include "llvm/Support/PrettyStackTrace.h"
26#include "llvm/Support/Signals.h"
27#include "llvm/Support/SourceMgr.h"
28#include "llvm/Support/SystemUtils.h"
29#include "llvm/Support/ToolOutputFile.h"
30#include <memory>
31using namespace llvm;
32
33static cl::opt<std::string>
34InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
35
36static cl::opt<std::string>
37OutputFilename("o", cl::desc("Override output filename"),
38               cl::value_desc("filename"));
39
40static cl::opt<bool>
41Force("f", cl::desc("Enable binary output on terminals"));
42
43static cl::opt<bool>
44DisableOutput("disable-output", cl::desc("Disable output"), cl::init(false));
45
46static cl::opt<bool>
47DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
48
49static cl::opt<bool>
50DisableVerify("disable-verify", cl::Hidden,
51              cl::desc("Do not run verifier on input LLVM (dangerous!)"));
52
53static 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(new tool_output_file(
73      OutputFilename.c_str(), ErrorInfo, sys::fs::F_Binary));
74  if (!ErrorInfo.empty()) {
75    errs() << ErrorInfo << '\n';
76    exit(1);
77  }
78
79  if (Force || !CheckBitcodeOutputToConsole(Out->os(), true))
80    WriteBitcodeToFile(M, Out->os());
81
82  // Declare success.
83  Out->keep();
84}
85
86int main(int argc, char **argv) {
87  // Print a stack trace if we signal out.
88  sys::PrintStackTraceOnErrorSignal();
89  PrettyStackTraceProgram X(argc, argv);
90  LLVMContext &Context = getGlobalContext();
91  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
92  cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
93
94  // Parse the file now...
95  SMDiagnostic Err;
96  OwningPtr<Module> M(ParseAssemblyFile(InputFilename, Err, Context));
97  if (M.get() == 0) {
98    Err.print(argv[0], errs());
99    return 1;
100  }
101
102  if (!DisableVerify) {
103    std::string Err;
104    if (verifyModule(*M.get(), ReturnStatusAction, &Err)) {
105      errs() << argv[0]
106             << ": assembly parsed, but does not verify as correct!\n";
107      errs() << Err;
108      return 1;
109    }
110  }
111
112  if (DumpAsm) errs() << "Here's the assembly:\n" << *M.get();
113
114  if (!DisableOutput)
115    WriteOutputFile(M.get());
116
117  return 0;
118}
119