1 //===- ModuleToObject.cpp - Module to object base class ---------*- C++ -*-===// 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 file implements the base class for transforming Operations into binary 10 // objects. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "mlir/Target/LLVM/ModuleToObject.h" 15 16 #include "mlir/ExecutionEngine/OptUtils.h" 17 #include "mlir/IR/BuiltinOps.h" 18 #include "mlir/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.h" 19 #include "mlir/Target/LLVMIR/Export.h" 20 #include "mlir/Target/LLVMIR/ModuleTranslation.h" 21 22 #include "llvm/Bitcode/BitcodeWriter.h" 23 #include "llvm/IR/LegacyPassManager.h" 24 #include "llvm/IRReader/IRReader.h" 25 #include "llvm/Linker/Linker.h" 26 #include "llvm/MC/TargetRegistry.h" 27 #include "llvm/Support/FileSystem.h" 28 #include "llvm/Support/Path.h" 29 #include "llvm/Support/SourceMgr.h" 30 #include "llvm/Support/raw_ostream.h" 31 #include "llvm/Target/TargetMachine.h" 32 #include "llvm/TargetParser/TargetParser.h" 33 #include "llvm/Transforms/IPO/Internalize.h" 34 35 using namespace mlir; 36 using namespace mlir::LLVM; 37 38 ModuleToObject::ModuleToObject(Operation &module, StringRef triple, 39 StringRef chip, StringRef features, int optLevel) 40 : module(module), triple(triple), chip(chip), features(features), 41 optLevel(optLevel) {} 42 43 Operation &ModuleToObject::getOperation() { return module; } 44 45 std::unique_ptr<llvm::TargetMachine> ModuleToObject::createTargetMachine() { 46 std::string error; 47 // Load the target. 48 const llvm::Target *target = 49 llvm::TargetRegistry::lookupTarget(triple, error); 50 if (!target) { 51 getOperation().emitError() << "Failed to lookup target: " << error; 52 return {}; 53 } 54 55 // Create the target machine using the target. 56 llvm::TargetMachine *machine = 57 target->createTargetMachine(triple, chip, features, {}, {}); 58 if (!machine) { 59 getOperation().emitError() << "Failed to create the target machine."; 60 return {}; 61 } 62 return std::unique_ptr<llvm::TargetMachine>{machine}; 63 } 64 65 std::unique_ptr<llvm::Module> 66 ModuleToObject::loadBitcodeFile(llvm::LLVMContext &context, 67 llvm::TargetMachine &targetMachine, 68 StringRef path) { 69 llvm::SMDiagnostic error; 70 std::unique_ptr<llvm::Module> library = 71 llvm::getLazyIRFileModule(path, error, context); 72 if (!library) { 73 getOperation().emitError() << "Failed loading file from " << path 74 << ", error: " << error.getMessage(); 75 return nullptr; 76 } 77 if (failed(handleBitcodeFile(*library, targetMachine))) { 78 return nullptr; 79 } 80 return library; 81 } 82 83 LogicalResult ModuleToObject::loadBitcodeFilesFromList( 84 llvm::LLVMContext &context, llvm::TargetMachine &targetMachine, 85 ArrayRef<std::string> fileList, 86 SmallVector<std::unique_ptr<llvm::Module>> &llvmModules, 87 bool failureOnError) { 88 for (const std::string &str : fileList) { 89 // Test if the path exists, if it doesn't abort. 90 StringRef pathRef = StringRef(str.data(), str.size()); 91 if (!llvm::sys::fs::is_regular_file(pathRef)) { 92 getOperation().emitError() 93 << "File path: " << pathRef << " does not exist or is not a file.\n"; 94 return failure(); 95 } 96 // Load the file or abort on error. 97 if (auto bcFile = loadBitcodeFile(context, targetMachine, pathRef)) 98 llvmModules.push_back(std::move(bcFile)); 99 else if (failureOnError) 100 return failure(); 101 } 102 return success(); 103 } 104 105 std::unique_ptr<llvm::Module> 106 ModuleToObject::translateToLLVMIR(llvm::LLVMContext &llvmContext) { 107 return translateModuleToLLVMIR(&getOperation(), llvmContext); 108 } 109 110 LogicalResult 111 ModuleToObject::linkFiles(llvm::Module &module, 112 SmallVector<std::unique_ptr<llvm::Module>> &&libs) { 113 if (libs.empty()) 114 return success(); 115 llvm::Linker linker(module); 116 for (std::unique_ptr<llvm::Module> &libModule : libs) { 117 // This bitcode linking imports the library functions into the module, 118 // allowing LLVM optimization passes (which must run after linking) to 119 // optimize across the libraries and the module's code. We also only import 120 // symbols if they are referenced by the module or a previous library since 121 // there will be no other source of references to those symbols in this 122 // compilation and since we don't want to bloat the resulting code object. 123 bool err = linker.linkInModule( 124 std::move(libModule), llvm::Linker::Flags::LinkOnlyNeeded, 125 [](llvm::Module &m, const StringSet<> &gvs) { 126 llvm::internalizeModule(m, [&gvs](const llvm::GlobalValue &gv) { 127 return !gv.hasName() || (gvs.count(gv.getName()) == 0); 128 }); 129 }); 130 // True is linker failure 131 if (err) { 132 getOperation().emitError("Unrecoverable failure during bitcode linking."); 133 // We have no guaranties about the state of `ret`, so bail 134 return failure(); 135 } 136 } 137 return success(); 138 } 139 140 LogicalResult ModuleToObject::optimizeModule(llvm::Module &module, 141 llvm::TargetMachine &targetMachine, 142 int optLevel) { 143 if (optLevel < 0 || optLevel > 3) 144 return getOperation().emitError() 145 << "Invalid optimization level: " << optLevel << "."; 146 147 targetMachine.setOptLevel(static_cast<llvm::CodeGenOpt::Level>(optLevel)); 148 149 auto transformer = 150 makeOptimizingTransformer(optLevel, /*sizeLevel=*/0, &targetMachine); 151 auto error = transformer(&module); 152 if (error) { 153 InFlightDiagnostic mlirError = getOperation().emitError(); 154 llvm::handleAllErrors( 155 std::move(error), [&mlirError](const llvm::ErrorInfoBase &ei) { 156 mlirError << "Could not optimize LLVM IR: " << ei.message() << "\n"; 157 }); 158 return mlirError; 159 } 160 return success(); 161 } 162 163 std::optional<std::string> 164 ModuleToObject::translateToISA(llvm::Module &llvmModule, 165 llvm::TargetMachine &targetMachine) { 166 std::string targetISA; 167 llvm::raw_string_ostream stream(targetISA); 168 169 { // Drop pstream after this to prevent the ISA from being stuck buffering 170 llvm::buffer_ostream pstream(stream); 171 llvm::legacy::PassManager codegenPasses; 172 173 if (targetMachine.addPassesToEmitFile(codegenPasses, pstream, nullptr, 174 llvm::CGFT_AssemblyFile)) 175 return std::nullopt; 176 177 codegenPasses.run(llvmModule); 178 } 179 return stream.str(); 180 } 181 182 std::optional<SmallVector<char, 0>> 183 ModuleToObject::moduleToObject(llvm::Module &llvmModule, 184 llvm::TargetMachine &targetMachine) { 185 SmallVector<char, 0> binaryData; 186 // Write the LLVM module bitcode to a buffer. 187 llvm::raw_svector_ostream outputStream(binaryData); 188 llvm::WriteBitcodeToFile(llvmModule, outputStream); 189 return binaryData; 190 } 191 192 std::optional<SmallVector<char, 0>> ModuleToObject::run() { 193 // Translate the module to LLVM IR. 194 llvm::LLVMContext llvmContext; 195 std::unique_ptr<llvm::Module> llvmModule = translateToLLVMIR(llvmContext); 196 if (!llvmModule) { 197 getOperation().emitError() << "Failed creating the llvm::Module."; 198 return std::nullopt; 199 } 200 201 // Create the target machine. 202 std::unique_ptr<llvm::TargetMachine> targetMachine = createTargetMachine(); 203 if (!targetMachine) 204 return std::nullopt; 205 206 // Set the data layout and target triple of the module. 207 llvmModule->setDataLayout(targetMachine->createDataLayout()); 208 llvmModule->setTargetTriple(targetMachine->getTargetTriple().getTriple()); 209 210 // Link bitcode files. 211 handleModulePreLink(*llvmModule, *targetMachine); 212 { 213 auto libs = loadBitcodeFiles(*llvmModule, *targetMachine); 214 if (!libs) 215 return std::nullopt; 216 if (libs->size()) 217 if (failed(linkFiles(*llvmModule, std::move(*libs)))) 218 return std::nullopt; 219 handleModulePostLink(*llvmModule, *targetMachine); 220 } 221 222 // Optimize the module. 223 if (failed(optimizeModule(*llvmModule, *targetMachine, optLevel))) 224 return std::nullopt; 225 226 // Return the serialized object. 227 return moduleToObject(*llvmModule, *targetMachine); 228 } 229