1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "jni_compiler.h" 18 19 #include "base/logging.h" 20 #include "class_linker.h" 21 #include "compiled_method.h" 22 #include "dex_file-inl.h" 23 #include "driver/compiler_driver.h" 24 #include "driver/dex_compilation_unit.h" 25 #include "llvm/compiler_llvm.h" 26 #include "llvm/ir_builder.h" 27 #include "llvm/llvm_compilation_unit.h" 28 #include "llvm/runtime_support_llvm_func.h" 29 #include "llvm/utils_llvm.h" 30 #include "mirror/art_method.h" 31 #include "runtime.h" 32 #include "stack.h" 33 #include "thread.h" 34 35 #include <llvm/ADT/SmallVector.h> 36 #include <llvm/IR/BasicBlock.h> 37 #include <llvm/IR/DerivedTypes.h> 38 #include <llvm/IR/Function.h> 39 #include <llvm/IR/Type.h> 40 41 namespace art { 42 namespace llvm { 43 44 using ::art::llvm::runtime_support::JniMethodEnd; 45 using ::art::llvm::runtime_support::JniMethodEndSynchronized; 46 using ::art::llvm::runtime_support::JniMethodEndWithReference; 47 using ::art::llvm::runtime_support::JniMethodEndWithReferenceSynchronized; 48 using ::art::llvm::runtime_support::JniMethodStart; 49 using ::art::llvm::runtime_support::JniMethodStartSynchronized; 50 using ::art::llvm::runtime_support::RuntimeId; 51 52 JniCompiler::JniCompiler(LlvmCompilationUnit* cunit, 53 CompilerDriver& driver, 54 const DexCompilationUnit* dex_compilation_unit) 55 : cunit_(cunit), driver_(&driver), module_(cunit_->GetModule()), 56 context_(cunit_->GetLLVMContext()), irb_(*cunit_->GetIRBuilder()), 57 dex_compilation_unit_(dex_compilation_unit), 58 func_(NULL), elf_func_idx_(0) { 59 // Check: Ensure that JNI compiler will only get "native" method 60 CHECK(dex_compilation_unit->IsNative()); 61 } 62 63 CompiledMethod* JniCompiler::Compile() { 64 const bool is_static = dex_compilation_unit_->IsStatic(); 65 const bool is_synchronized = dex_compilation_unit_->IsSynchronized(); 66 const DexFile* dex_file = dex_compilation_unit_->GetDexFile(); 67 DexFile::MethodId const& method_id = 68 dex_file->GetMethodId(dex_compilation_unit_->GetDexMethodIndex()); 69 char const return_shorty = dex_file->GetMethodShorty(method_id)[0]; 70 ::llvm::Value* this_object_or_class_object; 71 72 uint32_t method_idx = dex_compilation_unit_->GetDexMethodIndex(); 73 std::string func_name(StringPrintf("jni_%s", 74 MangleForJni(PrettyMethod(method_idx, *dex_file)).c_str())); 75 CreateFunction(func_name); 76 77 // Set argument name 78 ::llvm::Function::arg_iterator arg_begin(func_->arg_begin()); 79 ::llvm::Function::arg_iterator arg_end(func_->arg_end()); 80 ::llvm::Function::arg_iterator arg_iter(arg_begin); 81 82 DCHECK_NE(arg_iter, arg_end); 83 arg_iter->setName("method"); 84 ::llvm::Value* method_object_addr = arg_iter++; 85 86 if (!is_static) { 87 // Non-static, the second argument is "this object" 88 this_object_or_class_object = arg_iter++; 89 } else { 90 // Load class object 91 this_object_or_class_object = 92 irb_.LoadFromObjectOffset(method_object_addr, 93 mirror::ArtMethod::DeclaringClassOffset().Int32Value(), 94 irb_.getJObjectTy(), 95 kTBAAConstJObject); 96 } 97 // Actual argument (ignore method and this object) 98 arg_begin = arg_iter; 99 100 // Count the number of Object* arguments 101 uint32_t sirt_size = 1; 102 // "this" object pointer for non-static 103 // "class" object pointer for static 104 for (unsigned i = 0; arg_iter != arg_end; ++i, ++arg_iter) { 105 #if !defined(NDEBUG) 106 arg_iter->setName(StringPrintf("a%u", i)); 107 #endif 108 if (arg_iter->getType() == irb_.getJObjectTy()) { 109 ++sirt_size; 110 } 111 } 112 113 // Shadow stack 114 ::llvm::StructType* shadow_frame_type = irb_.getShadowFrameTy(sirt_size); 115 ::llvm::AllocaInst* shadow_frame_ = irb_.CreateAlloca(shadow_frame_type); 116 117 // Store the dex pc 118 irb_.StoreToObjectOffset(shadow_frame_, 119 ShadowFrame::DexPCOffset(), 120 irb_.getInt32(DexFile::kDexNoIndex), 121 kTBAAShadowFrame); 122 123 // Push the shadow frame 124 ::llvm::Value* shadow_frame_upcast = irb_.CreateConstGEP2_32(shadow_frame_, 0, 0); 125 ::llvm::Value* old_shadow_frame = 126 irb_.Runtime().EmitPushShadowFrame(shadow_frame_upcast, method_object_addr, sirt_size); 127 128 // Get JNIEnv 129 ::llvm::Value* jni_env_object_addr = 130 irb_.Runtime().EmitLoadFromThreadOffset(Thread::JniEnvOffset().Int32Value(), 131 irb_.getJObjectTy(), 132 kTBAARuntimeInfo); 133 134 // Get callee code_addr 135 ::llvm::Value* code_addr = 136 irb_.LoadFromObjectOffset(method_object_addr, 137 mirror::ArtMethod::NativeMethodOffset().Int32Value(), 138 GetFunctionType(dex_compilation_unit_->GetDexMethodIndex(), 139 is_static, true)->getPointerTo(), 140 kTBAARuntimeInfo); 141 142 // Load actual parameters 143 std::vector< ::llvm::Value*> args; 144 145 // The 1st parameter: JNIEnv* 146 args.push_back(jni_env_object_addr); 147 148 // Variables for GetElementPtr 149 ::llvm::Value* gep_index[] = { 150 irb_.getInt32(0), // No displacement for shadow frame pointer 151 irb_.getInt32(1), // SIRT 152 NULL, 153 }; 154 155 size_t sirt_member_index = 0; 156 157 // Store the "this object or class object" to SIRT 158 gep_index[2] = irb_.getInt32(sirt_member_index++); 159 ::llvm::Value* sirt_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index), 160 irb_.getJObjectTy()->getPointerTo()); 161 irb_.CreateStore(this_object_or_class_object, sirt_field_addr, kTBAAShadowFrame); 162 // Push the "this object or class object" to out args 163 this_object_or_class_object = irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy()); 164 args.push_back(this_object_or_class_object); 165 // Store arguments to SIRT, and push back to args 166 for (arg_iter = arg_begin; arg_iter != arg_end; ++arg_iter) { 167 if (arg_iter->getType() == irb_.getJObjectTy()) { 168 // Store the reference type arguments to SIRT 169 gep_index[2] = irb_.getInt32(sirt_member_index++); 170 ::llvm::Value* sirt_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index), 171 irb_.getJObjectTy()->getPointerTo()); 172 irb_.CreateStore(arg_iter, sirt_field_addr, kTBAAShadowFrame); 173 // Note null is placed in the SIRT but the jobject passed to the native code must be null 174 // (not a pointer into the SIRT as with regular references). 175 ::llvm::Value* equal_null = irb_.CreateICmpEQ(arg_iter, irb_.getJNull()); 176 ::llvm::Value* arg = 177 irb_.CreateSelect(equal_null, 178 irb_.getJNull(), 179 irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy())); 180 args.push_back(arg); 181 } else { 182 args.push_back(arg_iter); 183 } 184 } 185 186 ::llvm::Value* saved_local_ref_cookie; 187 { // JniMethodStart 188 RuntimeId func_id = is_synchronized ? JniMethodStartSynchronized 189 : JniMethodStart; 190 ::llvm::SmallVector< ::llvm::Value*, 2> args; 191 if (is_synchronized) { 192 args.push_back(this_object_or_class_object); 193 } 194 args.push_back(irb_.Runtime().EmitGetCurrentThread()); 195 saved_local_ref_cookie = 196 irb_.CreateCall(irb_.GetRuntime(func_id), args); 197 } 198 199 // Call!!! 200 ::llvm::Value* retval = irb_.CreateCall(code_addr, args); 201 202 { // JniMethodEnd 203 bool is_return_ref = return_shorty == 'L'; 204 RuntimeId func_id = 205 is_return_ref ? (is_synchronized ? JniMethodEndWithReferenceSynchronized 206 : JniMethodEndWithReference) 207 : (is_synchronized ? JniMethodEndSynchronized 208 : JniMethodEnd); 209 ::llvm::SmallVector< ::llvm::Value*, 4> args; 210 if (is_return_ref) { 211 args.push_back(retval); 212 } 213 args.push_back(saved_local_ref_cookie); 214 if (is_synchronized) { 215 args.push_back(this_object_or_class_object); 216 } 217 args.push_back(irb_.Runtime().EmitGetCurrentThread()); 218 219 ::llvm::Value* decoded_jobject = 220 irb_.CreateCall(irb_.GetRuntime(func_id), args); 221 222 // Return decoded jobject if return reference. 223 if (is_return_ref) { 224 retval = decoded_jobject; 225 } 226 } 227 228 // Pop the shadow frame 229 irb_.Runtime().EmitPopShadowFrame(old_shadow_frame); 230 231 // Return! 232 switch (return_shorty) { 233 case 'V': 234 irb_.CreateRetVoid(); 235 break; 236 case 'Z': 237 case 'C': 238 irb_.CreateRet(irb_.CreateZExt(retval, irb_.getInt32Ty())); 239 break; 240 case 'B': 241 case 'S': 242 irb_.CreateRet(irb_.CreateSExt(retval, irb_.getInt32Ty())); 243 break; 244 default: 245 irb_.CreateRet(retval); 246 break; 247 } 248 249 // Verify the generated bitcode 250 VERIFY_LLVM_FUNCTION(*func_); 251 252 cunit_->Materialize(); 253 254 return new CompiledMethod(*driver_, cunit_->GetInstructionSet(), cunit_->GetElfObject(), 255 func_name); 256 } 257 258 259 void JniCompiler::CreateFunction(const std::string& func_name) { 260 CHECK_NE(0U, func_name.size()); 261 262 const bool is_static = dex_compilation_unit_->IsStatic(); 263 264 // Get function type 265 ::llvm::FunctionType* func_type = 266 GetFunctionType(dex_compilation_unit_->GetDexMethodIndex(), is_static, false); 267 268 // Create function 269 func_ = ::llvm::Function::Create(func_type, ::llvm::Function::InternalLinkage, 270 func_name, module_); 271 272 // Create basic block 273 ::llvm::BasicBlock* basic_block = ::llvm::BasicBlock::Create(*context_, "B0", func_); 274 275 // Set insert point 276 irb_.SetInsertPoint(basic_block); 277 } 278 279 280 ::llvm::FunctionType* JniCompiler::GetFunctionType(uint32_t method_idx, 281 bool is_static, bool is_native_function) { 282 // Get method signature 283 uint32_t shorty_size; 284 const char* shorty = dex_compilation_unit_->GetShorty(&shorty_size); 285 CHECK_GE(shorty_size, 1u); 286 287 // Get return type 288 ::llvm::Type* ret_type = NULL; 289 switch (shorty[0]) { 290 case 'V': ret_type = irb_.getJVoidTy(); break; 291 case 'Z': 292 case 'B': 293 case 'C': 294 case 'S': 295 case 'I': ret_type = irb_.getJIntTy(); break; 296 case 'F': ret_type = irb_.getJFloatTy(); break; 297 case 'J': ret_type = irb_.getJLongTy(); break; 298 case 'D': ret_type = irb_.getJDoubleTy(); break; 299 case 'L': ret_type = irb_.getJObjectTy(); break; 300 default: LOG(FATAL) << "Unreachable: unexpected return type in shorty " << shorty; 301 } 302 // Get argument type 303 std::vector< ::llvm::Type*> args_type; 304 305 args_type.push_back(irb_.getJObjectTy()); // method object pointer 306 307 if (!is_static || is_native_function) { 308 // "this" object pointer for non-static 309 // "class" object pointer for static naitve 310 args_type.push_back(irb_.getJType('L')); 311 } 312 313 for (uint32_t i = 1; i < shorty_size; ++i) { 314 args_type.push_back(irb_.getJType(shorty[i])); 315 } 316 317 return ::llvm::FunctionType::get(ret_type, args_type, false); 318 } 319 320 } // namespace llvm 321 } // namespace art 322
