| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "base/stl_util.h" |
| #include "dex_file.h" |
| #include "dex_instruction.h" |
| #include "dex_instruction-inl.h" |
| #include "base/mutex.h" |
| #include "base/mutex-inl.h" |
| #include "mirror/art_method.h" |
| #include "mirror/art_method-inl.h" |
| #include "mirror/class.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/dex_cache.h" |
| #include "mirror/dex_cache-inl.h" |
| #include "mirror/object.h" |
| #include "mirror/object-inl.h" |
| #include "verified_methods_data.h" |
| #include "verifier/dex_gc_map.h" |
| #include "verifier/method_verifier.h" |
| #include "verifier/method_verifier-inl.h" |
| #include "verifier/register_line.h" |
| #include "verifier/register_line-inl.h" |
| |
| namespace art { |
| |
| VerifiedMethodsData::VerifiedMethodsData() |
| : dex_gc_maps_lock_("compiler GC maps lock"), |
| dex_gc_maps_(), |
| safecast_map_lock_("compiler Cast Elision lock"), |
| safecast_map_(), |
| devirt_maps_lock_("compiler Devirtualization lock"), |
| devirt_maps_(), |
| rejected_classes_lock_("compiler rejected classes lock"), |
| rejected_classes_() { |
| } |
| |
| VerifiedMethodsData::~VerifiedMethodsData() { |
| Thread* self = Thread::Current(); |
| { |
| WriterMutexLock mu(self, dex_gc_maps_lock_); |
| STLDeleteValues(&dex_gc_maps_); |
| } |
| { |
| WriterMutexLock mu(self, safecast_map_lock_); |
| STLDeleteValues(&safecast_map_); |
| } |
| { |
| WriterMutexLock mu(self, devirt_maps_lock_); |
| STLDeleteValues(&devirt_maps_); |
| } |
| } |
| |
| bool VerifiedMethodsData::ProcessVerifiedMethod(verifier::MethodVerifier* method_verifier) { |
| MethodReference ref = method_verifier->GetMethodReference(); |
| bool compile = IsCandidateForCompilation(ref, method_verifier->GetAccessFlags()); |
| if (compile) { |
| /* Generate a register map and add it to the method. */ |
| const std::vector<uint8_t>* dex_gc_map = GenerateGcMap(method_verifier); |
| if (dex_gc_map == NULL) { |
| DCHECK(method_verifier->HasFailures()); |
| return false; // Not a real failure, but a failure to encode |
| } |
| if (kIsDebugBuild) { |
| VerifyGcMap(method_verifier, *dex_gc_map); |
| } |
| SetDexGcMap(ref, dex_gc_map); |
| |
| // TODO: move this out when DEX-to-DEX supports devirtualization. |
| if (method_verifier->HasVirtualOrInterfaceInvokes()) { |
| PcToConcreteMethodMap* pc_to_concrete_method = GenerateDevirtMap(method_verifier); |
| if (pc_to_concrete_method != NULL) { |
| SetDevirtMap(ref, pc_to_concrete_method); |
| } |
| } |
| } |
| |
| if (method_verifier->HasCheckCasts()) { |
| MethodSafeCastSet* method_to_safe_casts = GenerateSafeCastSet(method_verifier); |
| if (method_to_safe_casts != NULL) { |
| SetSafeCastMap(ref, method_to_safe_casts); |
| } |
| } |
| return true; |
| } |
| |
| const std::vector<uint8_t>* VerifiedMethodsData::GetDexGcMap(MethodReference ref) { |
| ReaderMutexLock mu(Thread::Current(), dex_gc_maps_lock_); |
| DexGcMapTable::const_iterator it = dex_gc_maps_.find(ref); |
| CHECK(it != dex_gc_maps_.end()) |
| << "Didn't find GC map for: " << PrettyMethod(ref.dex_method_index, *ref.dex_file); |
| CHECK(it->second != NULL); |
| return it->second; |
| } |
| |
| const MethodReference* VerifiedMethodsData::GetDevirtMap(const MethodReference& ref, |
| uint32_t dex_pc) { |
| ReaderMutexLock mu(Thread::Current(), devirt_maps_lock_); |
| DevirtualizationMapTable::const_iterator it = devirt_maps_.find(ref); |
| if (it == devirt_maps_.end()) { |
| return NULL; |
| } |
| |
| // Look up the PC in the map, get the concrete method to execute and return its reference. |
| PcToConcreteMethodMap::const_iterator pc_to_concrete_method = it->second->find(dex_pc); |
| if (pc_to_concrete_method != it->second->end()) { |
| return &(pc_to_concrete_method->second); |
| } else { |
| return NULL; |
| } |
| } |
| |
| bool VerifiedMethodsData::IsSafeCast(MethodReference ref, uint32_t pc) { |
| ReaderMutexLock mu(Thread::Current(), safecast_map_lock_); |
| SafeCastMap::const_iterator it = safecast_map_.find(ref); |
| if (it == safecast_map_.end()) { |
| return false; |
| } |
| |
| // Look up the cast address in the set of safe casts |
| // Use binary_search for lookup in the sorted vector. |
| return std::binary_search(it->second->begin(), it->second->end(), pc); |
| } |
| |
| void VerifiedMethodsData::AddRejectedClass(ClassReference ref) { |
| { |
| WriterMutexLock mu(Thread::Current(), rejected_classes_lock_); |
| rejected_classes_.insert(ref); |
| } |
| DCHECK(IsClassRejected(ref)); |
| } |
| |
| bool VerifiedMethodsData::IsClassRejected(ClassReference ref) { |
| ReaderMutexLock mu(Thread::Current(), rejected_classes_lock_); |
| return (rejected_classes_.find(ref) != rejected_classes_.end()); |
| } |
| |
| bool VerifiedMethodsData::IsCandidateForCompilation(MethodReference& method_ref, |
| const uint32_t access_flags) { |
| #ifdef ART_SEA_IR_MODE |
| bool use_sea = Runtime::Current()->IsSeaIRMode(); |
| use_sea = use_sea && (std::string::npos != PrettyMethod( |
| method_ref.dex_method_index, *(method_ref.dex_file)).find("fibonacci")); |
| if (use_sea) return true; |
| #endif |
| // Don't compile class initializers, ever. |
| if (((access_flags & kAccConstructor) != 0) && ((access_flags & kAccStatic) != 0)) { |
| return false; |
| } |
| return (Runtime::Current()->GetCompilerFilter() != Runtime::kInterpretOnly); |
| } |
| |
| const std::vector<uint8_t>* VerifiedMethodsData::GenerateGcMap( |
| verifier::MethodVerifier* method_verifier) { |
| size_t num_entries, ref_bitmap_bits, pc_bits; |
| ComputeGcMapSizes(method_verifier, &num_entries, &ref_bitmap_bits, &pc_bits); |
| // There's a single byte to encode the size of each bitmap |
| if (ref_bitmap_bits >= (8 /* bits per byte */ * 8192 /* 13-bit size */ )) { |
| // TODO: either a better GC map format or per method failures |
| method_verifier->Fail(verifier::VERIFY_ERROR_BAD_CLASS_HARD) |
| << "Cannot encode GC map for method with " << ref_bitmap_bits << " registers"; |
| return NULL; |
| } |
| size_t ref_bitmap_bytes = (ref_bitmap_bits + 7) / 8; |
| // There are 2 bytes to encode the number of entries |
| if (num_entries >= 65536) { |
| // TODO: either a better GC map format or per method failures |
| method_verifier->Fail(verifier::VERIFY_ERROR_BAD_CLASS_HARD) |
| << "Cannot encode GC map for method with " << num_entries << " entries"; |
| return NULL; |
| } |
| size_t pc_bytes; |
| verifier::RegisterMapFormat format; |
| if (pc_bits <= 8) { |
| format = verifier::kRegMapFormatCompact8; |
| pc_bytes = 1; |
| } else if (pc_bits <= 16) { |
| format = verifier::kRegMapFormatCompact16; |
| pc_bytes = 2; |
| } else { |
| // TODO: either a better GC map format or per method failures |
| method_verifier->Fail(verifier::VERIFY_ERROR_BAD_CLASS_HARD) |
| << "Cannot encode GC map for method with " |
| << (1 << pc_bits) << " instructions (number is rounded up to nearest power of 2)"; |
| return NULL; |
| } |
| size_t table_size = ((pc_bytes + ref_bitmap_bytes) * num_entries) + 4; |
| std::vector<uint8_t>* table = new std::vector<uint8_t>; |
| if (table == NULL) { |
| method_verifier->Fail(verifier::VERIFY_ERROR_BAD_CLASS_HARD) |
| << "Failed to encode GC map (size=" << table_size << ")"; |
| return NULL; |
| } |
| table->reserve(table_size); |
| // Write table header |
| table->push_back(format | ((ref_bitmap_bytes & ~0xFF) >> 5)); |
| table->push_back(ref_bitmap_bytes & 0xFF); |
| table->push_back(num_entries & 0xFF); |
| table->push_back((num_entries >> 8) & 0xFF); |
| // Write table data |
| const DexFile::CodeItem* code_item = method_verifier->CodeItem(); |
| for (size_t i = 0; i < code_item->insns_size_in_code_units_; i++) { |
| if (method_verifier->GetInstructionFlags(i).IsCompileTimeInfoPoint()) { |
| table->push_back(i & 0xFF); |
| if (pc_bytes == 2) { |
| table->push_back((i >> 8) & 0xFF); |
| } |
| verifier::RegisterLine* line = method_verifier->GetRegLine(i); |
| line->WriteReferenceBitMap(*table, ref_bitmap_bytes); |
| } |
| } |
| DCHECK_EQ(table->size(), table_size); |
| return table; |
| } |
| |
| void VerifiedMethodsData::VerifyGcMap(verifier::MethodVerifier* method_verifier, |
| const std::vector<uint8_t>& data) { |
| // Check that for every GC point there is a map entry, there aren't entries for non-GC points, |
| // that the table data is well formed and all references are marked (or not) in the bitmap |
| verifier::DexPcToReferenceMap map(&data[0]); |
| DCHECK_EQ(data.size(), map.RawSize()); |
| size_t map_index = 0; |
| const DexFile::CodeItem* code_item = method_verifier->CodeItem(); |
| for (size_t i = 0; i < code_item->insns_size_in_code_units_; i++) { |
| const uint8_t* reg_bitmap = map.FindBitMap(i, false); |
| if (method_verifier->GetInstructionFlags(i).IsCompileTimeInfoPoint()) { |
| CHECK_LT(map_index, map.NumEntries()); |
| CHECK_EQ(map.GetDexPc(map_index), i); |
| CHECK_EQ(map.GetBitMap(map_index), reg_bitmap); |
| map_index++; |
| verifier::RegisterLine* line = method_verifier->GetRegLine(i); |
| for (size_t j = 0; j < code_item->registers_size_; j++) { |
| if (line->GetRegisterType(j).IsNonZeroReferenceTypes()) { |
| CHECK_LT(j / 8, map.RegWidth()); |
| CHECK_EQ((reg_bitmap[j / 8] >> (j % 8)) & 1, 1); |
| } else if ((j / 8) < map.RegWidth()) { |
| CHECK_EQ((reg_bitmap[j / 8] >> (j % 8)) & 1, 0); |
| } else { |
| // If a register doesn't contain a reference then the bitmap may be shorter than the line |
| } |
| } |
| } else { |
| CHECK(reg_bitmap == NULL); |
| } |
| } |
| } |
| |
| void VerifiedMethodsData::ComputeGcMapSizes(verifier::MethodVerifier* method_verifier, |
| size_t* gc_points, size_t* ref_bitmap_bits, |
| size_t* log2_max_gc_pc) { |
| size_t local_gc_points = 0; |
| size_t max_insn = 0; |
| size_t max_ref_reg = -1; |
| const DexFile::CodeItem* code_item = method_verifier->CodeItem(); |
| for (size_t i = 0; i < code_item->insns_size_in_code_units_; i++) { |
| if (method_verifier->GetInstructionFlags(i).IsCompileTimeInfoPoint()) { |
| local_gc_points++; |
| max_insn = i; |
| verifier::RegisterLine* line = method_verifier->GetRegLine(i); |
| max_ref_reg = line->GetMaxNonZeroReferenceReg(max_ref_reg); |
| } |
| } |
| *gc_points = local_gc_points; |
| *ref_bitmap_bits = max_ref_reg + 1; // if max register is 0 we need 1 bit to encode (ie +1) |
| size_t i = 0; |
| while ((1U << i) <= max_insn) { |
| i++; |
| } |
| *log2_max_gc_pc = i; |
| } |
| |
| void VerifiedMethodsData::SetDexGcMap(MethodReference ref, const std::vector<uint8_t>* gc_map) { |
| DCHECK(Runtime::Current()->IsCompiler()); |
| { |
| WriterMutexLock mu(Thread::Current(), dex_gc_maps_lock_); |
| DexGcMapTable::iterator it = dex_gc_maps_.find(ref); |
| if (it != dex_gc_maps_.end()) { |
| delete it->second; |
| dex_gc_maps_.erase(it); |
| } |
| dex_gc_maps_.Put(ref, gc_map); |
| } |
| DCHECK(GetDexGcMap(ref) != NULL); |
| } |
| |
| VerifiedMethodsData::MethodSafeCastSet* VerifiedMethodsData::GenerateSafeCastSet( |
| verifier::MethodVerifier* method_verifier) { |
| /* |
| * Walks over the method code and adds any cast instructions in which |
| * the type cast is implicit to a set, which is used in the code generation |
| * to elide these casts. |
| */ |
| if (method_verifier->HasFailures()) { |
| return NULL; |
| } |
| UniquePtr<MethodSafeCastSet> mscs; |
| const DexFile::CodeItem* code_item = method_verifier->CodeItem(); |
| const Instruction* inst = Instruction::At(code_item->insns_); |
| const Instruction* end = Instruction::At(code_item->insns_ + |
| code_item->insns_size_in_code_units_); |
| |
| for (; inst < end; inst = inst->Next()) { |
| Instruction::Code code = inst->Opcode(); |
| if ((code == Instruction::CHECK_CAST) || (code == Instruction::APUT_OBJECT)) { |
| uint32_t dex_pc = inst->GetDexPc(code_item->insns_); |
| const verifier::RegisterLine* line = method_verifier->GetRegLine(dex_pc); |
| bool is_safe_cast = false; |
| if (code == Instruction::CHECK_CAST) { |
| const verifier::RegType& reg_type(line->GetRegisterType(inst->VRegA_21c())); |
| const verifier::RegType& cast_type = |
| method_verifier->ResolveCheckedClass(inst->VRegB_21c()); |
| is_safe_cast = cast_type.IsStrictlyAssignableFrom(reg_type); |
| } else { |
| const verifier::RegType& array_type(line->GetRegisterType(inst->VRegB_23x())); |
| // We only know its safe to assign to an array if the array type is precise. For example, |
| // an Object[] can have any type of object stored in it, but it may also be assigned a |
| // String[] in which case the stores need to be of Strings. |
| if (array_type.IsPreciseReference()) { |
| const verifier::RegType& value_type(line->GetRegisterType(inst->VRegA_23x())); |
| const verifier::RegType& component_type = method_verifier->GetRegTypeCache() |
| ->GetComponentType(array_type, method_verifier->GetClassLoader()); |
| is_safe_cast = component_type.IsStrictlyAssignableFrom(value_type); |
| } |
| } |
| if (is_safe_cast) { |
| if (mscs.get() == nullptr) { |
| mscs.reset(new MethodSafeCastSet()); |
| } else { |
| DCHECK_LT(mscs->back(), dex_pc); // Verify ordering for push_back() to the sorted vector. |
| } |
| mscs->push_back(dex_pc); |
| } |
| } |
| } |
| return mscs.release(); |
| } |
| |
| void VerifiedMethodsData::SetSafeCastMap(MethodReference ref, const MethodSafeCastSet* cast_set) { |
| WriterMutexLock mu(Thread::Current(), safecast_map_lock_); |
| SafeCastMap::iterator it = safecast_map_.find(ref); |
| if (it != safecast_map_.end()) { |
| delete it->second; |
| safecast_map_.erase(it); |
| } |
| safecast_map_.Put(ref, cast_set); |
| DCHECK(safecast_map_.find(ref) != safecast_map_.end()); |
| } |
| |
| VerifiedMethodsData::PcToConcreteMethodMap* VerifiedMethodsData::GenerateDevirtMap( |
| verifier::MethodVerifier* method_verifier) { |
| // It is risky to rely on reg_types for sharpening in cases of soft |
| // verification, we might end up sharpening to a wrong implementation. Just abort. |
| if (method_verifier->HasFailures()) { |
| return NULL; |
| } |
| |
| UniquePtr<PcToConcreteMethodMap> pc_to_concrete_method_map; |
| const DexFile::CodeItem* code_item = method_verifier->CodeItem(); |
| const uint16_t* insns = code_item->insns_; |
| const Instruction* inst = Instruction::At(insns); |
| const Instruction* end = Instruction::At(insns + code_item->insns_size_in_code_units_); |
| |
| for (; inst < end; inst = inst->Next()) { |
| bool is_virtual = (inst->Opcode() == Instruction::INVOKE_VIRTUAL) || |
| (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE); |
| bool is_interface = (inst->Opcode() == Instruction::INVOKE_INTERFACE) || |
| (inst->Opcode() == Instruction::INVOKE_INTERFACE_RANGE); |
| |
| if (!is_interface && !is_virtual) { |
| continue; |
| } |
| // Get reg type for register holding the reference to the object that will be dispatched upon. |
| uint32_t dex_pc = inst->GetDexPc(insns); |
| verifier::RegisterLine* line = method_verifier->GetRegLine(dex_pc); |
| bool is_range = (inst->Opcode() == Instruction::INVOKE_VIRTUAL_RANGE) || |
| (inst->Opcode() == Instruction::INVOKE_INTERFACE_RANGE); |
| const verifier::RegType& |
| reg_type(line->GetRegisterType(is_range ? inst->VRegC_3rc() : inst->VRegC_35c())); |
| |
| if (!reg_type.HasClass()) { |
| // We will compute devirtualization information only when we know the Class of the reg type. |
| continue; |
| } |
| mirror::Class* reg_class = reg_type.GetClass(); |
| if (reg_class->IsInterface()) { |
| // We can't devirtualize when the known type of the register is an interface. |
| continue; |
| } |
| if (reg_class->IsAbstract() && !reg_class->IsArrayClass()) { |
| // We can't devirtualize abstract classes except on arrays of abstract classes. |
| continue; |
| } |
| mirror::ArtMethod* abstract_method = method_verifier->GetDexCache()->GetResolvedMethod( |
| is_range ? inst->VRegB_3rc() : inst->VRegB_35c()); |
| if (abstract_method == NULL) { |
| // If the method is not found in the cache this means that it was never found |
| // by ResolveMethodAndCheckAccess() called when verifying invoke_*. |
| continue; |
| } |
| // Find the concrete method. |
| mirror::ArtMethod* concrete_method = NULL; |
| if (is_interface) { |
| concrete_method = reg_type.GetClass()->FindVirtualMethodForInterface(abstract_method); |
| } |
| if (is_virtual) { |
| concrete_method = reg_type.GetClass()->FindVirtualMethodForVirtual(abstract_method); |
| } |
| if (concrete_method == NULL || concrete_method->IsAbstract()) { |
| // In cases where concrete_method is not found, or is abstract, continue to the next invoke. |
| continue; |
| } |
| if (reg_type.IsPreciseReference() || concrete_method->IsFinal() || |
| concrete_method->GetDeclaringClass()->IsFinal()) { |
| // If we knew exactly the class being dispatched upon, or if the target method cannot be |
| // overridden record the target to be used in the compiler driver. |
| if (pc_to_concrete_method_map.get() == NULL) { |
| pc_to_concrete_method_map.reset(new PcToConcreteMethodMap()); |
| } |
| MethodReference concrete_ref( |
| concrete_method->GetDeclaringClass()->GetDexCache()->GetDexFile(), |
| concrete_method->GetDexMethodIndex()); |
| pc_to_concrete_method_map->Put(dex_pc, concrete_ref); |
| } |
| } |
| return pc_to_concrete_method_map.release(); |
| } |
| |
| void VerifiedMethodsData::SetDevirtMap(MethodReference ref, |
| const PcToConcreteMethodMap* devirt_map) { |
| WriterMutexLock mu(Thread::Current(), devirt_maps_lock_); |
| DevirtualizationMapTable::iterator it = devirt_maps_.find(ref); |
| if (it != devirt_maps_.end()) { |
| delete it->second; |
| devirt_maps_.erase(it); |
| } |
| |
| devirt_maps_.Put(ref, devirt_map); |
| DCHECK(devirt_maps_.find(ref) != devirt_maps_.end()); |
| } |
| |
| } // namespace art |