1 //===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This utility may be invoked in the following manner: 10 // llvm-as --help - Output information about command line switches 11 // llvm-as [options] - Read LLVM asm from stdin, write bitcode to stdout 12 // llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode 13 // to the x.bc file. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "llvm/AsmParser/Parser.h" 18 #include "llvm/Bitcode/BitcodeWriter.h" 19 #include "llvm/IR/LLVMContext.h" 20 #include "llvm/IR/Module.h" 21 #include "llvm/IR/ModuleSummaryIndex.h" 22 #include "llvm/IR/Verifier.h" 23 #include "llvm/Support/CommandLine.h" 24 #include "llvm/Support/FileSystem.h" 25 #include "llvm/Support/InitLLVM.h" 26 #include "llvm/Support/ManagedStatic.h" 27 #include "llvm/Support/SourceMgr.h" 28 #include "llvm/Support/SystemUtils.h" 29 #include "llvm/Support/ToolOutputFile.h" 30 #include <memory> 31 using namespace llvm; 32 33 static cl::opt<std::string> InputFilename(cl::Positional, 34 cl::desc("<input .llvm file>"), 35 cl::init("-")); 36 37 static cl::opt<std::string> OutputFilename("o", 38 cl::desc("Override output filename"), 39 cl::value_desc("filename")); 40 41 static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals")); 42 43 static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"), 44 cl::init(false)); 45 46 static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"), 47 cl::init(false)); 48 49 static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"), 50 cl::Hidden); 51 52 static cl::opt<bool> 53 DisableVerify("disable-verify", cl::Hidden, 54 cl::desc("Do not run verifier on input LLVM (dangerous!)")); 55 56 static cl::opt<bool> PreserveBitcodeUseListOrder( 57 "preserve-bc-uselistorder", 58 cl::desc("Preserve use-list order when writing LLVM bitcode."), 59 cl::init(true), cl::Hidden); 60 61 static cl::opt<std::string> ClDataLayout("data-layout", 62 cl::desc("data layout string to use"), 63 cl::value_desc("layout-string"), 64 cl::init("")); 65 66 static void WriteOutputFile(const Module *M, const ModuleSummaryIndex *Index) { 67 // Infer the output filename if needed. 68 if (OutputFilename.empty()) { 69 if (InputFilename == "-") { 70 OutputFilename = "-"; 71 } else { 72 StringRef IFN = InputFilename; 73 OutputFilename = (IFN.endswith(".ll") ? IFN.drop_back(3) : IFN).str(); 74 OutputFilename += ".bc"; 75 } 76 } 77 78 std::error_code EC; 79 std::unique_ptr<ToolOutputFile> Out( 80 new ToolOutputFile(OutputFilename, EC, sys::fs::F_None)); 81 if (EC) { 82 errs() << EC.message() << '\n'; 83 exit(1); 84 } 85 86 if (Force || !CheckBitcodeOutputToConsole(Out->os(), true)) { 87 const ModuleSummaryIndex *IndexToWrite = nullptr; 88 // Don't attempt to write a summary index unless it contains any entries. 89 // Otherwise we get an empty summary section. 90 if (Index && Index->begin() != Index->end()) 91 IndexToWrite = Index; 92 if (!IndexToWrite || (M && (!M->empty() || !M->global_empty()))) 93 // If we have a non-empty Module, then we write the Module plus 94 // any non-null Index along with it as a per-module Index. 95 // If both are empty, this will give an empty module block, which is 96 // the expected behavior. 97 WriteBitcodeToFile(*M, Out->os(), PreserveBitcodeUseListOrder, 98 IndexToWrite, EmitModuleHash); 99 else 100 // Otherwise, with an empty Module but non-empty Index, we write a 101 // combined index. 102 WriteIndexToFile(*IndexToWrite, Out->os()); 103 } 104 105 // Declare success. 106 Out->keep(); 107 } 108 109 int main(int argc, char **argv) { 110 InitLLVM X(argc, argv); 111 LLVMContext Context; 112 cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n"); 113 114 // Parse the file now... 115 SMDiagnostic Err; 116 auto ModuleAndIndex = parseAssemblyFileWithIndex( 117 InputFilename, Err, Context, nullptr, !DisableVerify, ClDataLayout); 118 std::unique_ptr<Module> M = std::move(ModuleAndIndex.Mod); 119 if (!M.get()) { 120 Err.print(argv[0], errs()); 121 return 1; 122 } 123 std::unique_ptr<ModuleSummaryIndex> Index = std::move(ModuleAndIndex.Index); 124 125 if (!DisableVerify) { 126 std::string ErrorStr; 127 raw_string_ostream OS(ErrorStr); 128 if (verifyModule(*M.get(), &OS)) { 129 errs() << argv[0] 130 << ": assembly parsed, but does not verify as correct!\n"; 131 errs() << OS.str(); 132 return 1; 133 } 134 // TODO: Implement and call summary index verifier. 135 } 136 137 if (DumpAsm) { 138 errs() << "Here's the assembly:\n" << *M.get(); 139 if (Index.get() && Index->begin() != Index->end()) 140 Index->print(errs()); 141 } 142 143 if (!DisableOutput) 144 WriteOutputFile(M.get(), Index.get()); 145 146 return 0; 147 } 148