164 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8//9// This utility may be invoked in the following manner:10// llvm-as --help - Output information about command line switches11// llvm-as [options] - Read LLVM asm from stdin, write bitcode to stdout12// llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode13// 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/SourceMgr.h"27#include "llvm/Support/SystemUtils.h"28#include "llvm/Support/ToolOutputFile.h"29#include <memory>30#include <optional>31using namespace llvm;32 33static cl::OptionCategory AsCat("llvm-as Options");34 35static cl::opt<std::string>36 InputFilename(cl::Positional, cl::desc("<input .ll file>"), cl::init("-"));37 38static cl::opt<std::string> OutputFilename("o",39 cl::desc("Override output filename"),40 cl::value_desc("filename"),41 cl::cat(AsCat));42 43static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"),44 cl::cat(AsCat));45 46static cl::opt<bool> DisableOutput("disable-output", cl::desc("Disable output"),47 cl::init(false), cl::cat(AsCat));48 49static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),50 cl::init(false), cl::cat(AsCat));51 52static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as parsed"),53 cl::Hidden, cl::cat(AsCat));54 55static cl::opt<bool>56 DisableVerify("disable-verify", cl::Hidden,57 cl::desc("Do not run verifier on input LLVM (dangerous!)"),58 cl::cat(AsCat));59 60static cl::opt<std::string> ClDataLayout("data-layout",61 cl::desc("data layout string to use"),62 cl::value_desc("layout-string"),63 cl::init(""), cl::cat(AsCat));64 65static void WriteOutputFile(const Module *M, const ModuleSummaryIndex *Index) {66 // Infer the output filename if needed.67 if (OutputFilename.empty()) {68 if (InputFilename == "-") {69 OutputFilename = "-";70 } else {71 StringRef IFN = InputFilename;72 OutputFilename = (IFN.ends_with(".ll") ? IFN.drop_back(3) : IFN).str();73 OutputFilename += ".bc";74 }75 }76 77 std::error_code EC;78 std::unique_ptr<ToolOutputFile> Out(79 new ToolOutputFile(OutputFilename, EC, sys::fs::OF_None));80 if (EC) {81 errs() << EC.message() << '\n';82 exit(1);83 }84 85 if (Force || !CheckBitcodeOutputToConsole(Out->os())) {86 const ModuleSummaryIndex *IndexToWrite = nullptr;87 // Don't attempt to write a summary index unless it contains any entries or88 // has non-zero flags. The latter is used to assemble dummy index files for89 // skipping modules by distributed ThinLTO backends. Otherwise we get an empty90 // summary section.91 if (Index && (Index->begin() != Index->end() || Index->getFlags()))92 IndexToWrite = Index;93 if (!IndexToWrite || (M && (!M->empty() || !M->global_empty())))94 // If we have a non-empty Module, then we write the Module plus95 // any non-null Index along with it as a per-module Index.96 // If both are empty, this will give an empty module block, which is97 // the expected behavior.98 WriteBitcodeToFile(*M, Out->os(), /* ShouldPreserveUseListOrder */ true,99 IndexToWrite, EmitModuleHash);100 else101 // Otherwise, with an empty Module but non-empty Index, we write a102 // combined index.103 writeIndexToFile(*IndexToWrite, Out->os());104 }105 106 // Declare success.107 Out->keep();108}109 110int main(int argc, char **argv) {111 InitLLVM X(argc, argv);112 cl::HideUnrelatedOptions(AsCat);113 cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");114 LLVMContext Context;115 116 // Parse the file now...117 SMDiagnostic Err;118 auto SetDataLayout = [](StringRef, StringRef) -> std::optional<std::string> {119 if (ClDataLayout.empty())120 return std::nullopt;121 return ClDataLayout;122 };123 ParsedModuleAndIndex ModuleAndIndex;124 if (DisableVerify) {125 ModuleAndIndex = parseAssemblyFileWithIndexNoUpgradeDebugInfo(126 InputFilename, Err, Context, nullptr, SetDataLayout);127 } else {128 ModuleAndIndex = parseAssemblyFileWithIndex(InputFilename, Err, Context,129 nullptr, SetDataLayout);130 }131 std::unique_ptr<Module> M = std::move(ModuleAndIndex.Mod);132 if (!M) {133 Err.print(argv[0], errs());134 return 1;135 }136 137 M->removeDebugIntrinsicDeclarations();138 139 std::unique_ptr<ModuleSummaryIndex> Index = std::move(ModuleAndIndex.Index);140 141 if (!DisableVerify) {142 std::string ErrorStr;143 raw_string_ostream OS(ErrorStr);144 if (verifyModule(*M, &OS)) {145 errs() << argv[0]146 << ": assembly parsed, but does not verify as correct!\n";147 errs() << OS.str();148 return 1;149 }150 // TODO: Implement and call summary index verifier.151 }152 153 if (DumpAsm) {154 errs() << "Here's the assembly:\n" << *M;155 if (Index.get() && Index->begin() != Index->end())156 Index->print(errs());157 }158 159 if (!DisableOutput)160 WriteOutputFile(M.get(), Index.get());161 162 return 0;163}164