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      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 
     31 #include "BitWriter_3_2/ReaderWriter_3_2.h"
     32 #include "BitWriter_2_9/ReaderWriter_2_9.h"
     33 #include "BitWriter_2_9_func/ReaderWriter_2_9_func.h"
     34 
     35 #include <memory>
     36 using namespace llvm;
     37 
     38 static cl::opt<std::string>
     39 InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
     40 
     41 static cl::opt<std::string>
     42 OutputFilename("o", cl::desc("Override output filename"),
     43                cl::value_desc("filename"));
     44 
     45 static cl::opt<bool>
     46 Force("f", cl::desc("Enable binary output on terminals"));
     47 
     48 static cl::opt<bool>
     49 DisableOutput("disable-output", cl::desc("Disable output"), cl::init(false));
     50 
     51 static cl::opt<bool>
     52 DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
     53 
     54 static cl::opt<bool>
     55 DisableVerify("disable-verify", cl::Hidden,
     56               cl::desc("Do not run verifier on input LLVM (dangerous!)"));
     57 
     58 enum BCVersion {
     59   BC29, BC29Func, BC32, BCHEAD
     60 };
     61 
     62 cl::opt<BCVersion> BitcodeVersion("bitcode-version",
     63   cl::desc("Set the bitcode version to be written:"),
     64   cl::values(
     65     clEnumValN(BC29, "BC29", "Version 2.9"),
     66      clEnumVal(BC29Func,     "Version 2.9 func"),
     67      clEnumVal(BC32,         "Version 3.2"),
     68      clEnumVal(BCHEAD,       "Most current version"),
     69     clEnumValEnd), cl::init(BC32));
     70 
     71 static void WriteOutputFile(const Module *M) {
     72   // Infer the output filename if needed.
     73   if (OutputFilename.empty()) {
     74     if (InputFilename == "-") {
     75       OutputFilename = "-";
     76     } else {
     77       std::string IFN = InputFilename;
     78       int Len = IFN.length();
     79       if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
     80         // Source ends in .ll
     81         OutputFilename = std::string(IFN.begin(), IFN.end()-3);
     82       } else {
     83         OutputFilename = IFN;   // Append a .bc to it
     84       }
     85       OutputFilename += ".bc";
     86     }
     87   }
     88 
     89   std::string ErrorInfo;
     90   OwningPtr<tool_output_file> Out
     91   (new tool_output_file(OutputFilename.c_str(), ErrorInfo,
     92                         llvm::sys::fs::F_Binary));
     93   if (!ErrorInfo.empty()) {
     94     errs() << ErrorInfo << '\n';
     95     exit(1);
     96   }
     97 
     98   if (Force || !CheckBitcodeOutputToConsole(Out->os(), true)) {
     99     switch(BitcodeVersion) {
    100       case BC29:
    101         llvm_2_9::WriteBitcodeToFile(M, Out->os());
    102         break;
    103       case BC29Func:
    104         llvm_2_9_func::WriteBitcodeToFile(M, Out->os());
    105         break;
    106       case BC32:
    107         llvm_3_2::WriteBitcodeToFile(M, Out->os());
    108         break;
    109       case BCHEAD:
    110         llvm::WriteBitcodeToFile(M, Out->os());
    111         break;
    112     }
    113   }
    114 
    115   // Declare success.
    116   Out->keep();
    117 }
    118 
    119 int main(int argc, char **argv) {
    120   // Print a stack trace if we signal out.
    121   sys::PrintStackTraceOnErrorSignal();
    122   PrettyStackTraceProgram X(argc, argv);
    123   LLVMContext &Context = getGlobalContext();
    124   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
    125   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
    126 
    127   // Parse the file now...
    128   SMDiagnostic Err;
    129   OwningPtr<Module> M(ParseAssemblyFile(InputFilename, Err, Context));
    130   if (M.get() == 0) {
    131     Err.print(argv[0], errs());
    132     return 1;
    133   }
    134 
    135   if (!DisableVerify) {
    136     std::string Err;
    137     if (verifyModule(*M.get(), ReturnStatusAction, &Err)) {
    138       errs() << argv[0]
    139              << ": assembly parsed, but does not verify as correct!\n";
    140       errs() << Err;
    141       return 1;
    142     }
    143   }
    144 
    145   if (DumpAsm) errs() << "Here's the assembly:\n" << *M.get();
    146 
    147   if (!DisableOutput)
    148     WriteOutputFile(M.get());
    149 
    150   return 0;
    151 }
    152