1 /* 2 * Copyright (C) 2014 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 #ifndef ART_COMPILER_DEX_VERIFIED_METHOD_H_ 18 #define ART_COMPILER_DEX_VERIFIED_METHOD_H_ 19 20 #include <vector> 21 22 #include "base/mutex.h" 23 #include "method_reference.h" 24 #include "safe_map.h" 25 26 namespace art { 27 28 namespace verifier { 29 class MethodVerifier; 30 } // namespace verifier 31 32 class VerifiedMethod { 33 public: 34 // Cast elision set type. 35 // Since we're adding the dex PCs to the set in increasing order, a sorted vector 36 // is better for performance (not just memory usage), especially for large sets. 37 typedef std::vector<uint32_t> SafeCastSet; 38 39 // Devirtualization map type maps dex offset to concrete method reference. 40 typedef SafeMap<uint32_t, MethodReference> DevirtualizationMap; 41 42 static const VerifiedMethod* Create(verifier::MethodVerifier* method_verifier, bool compile) 43 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 44 ~VerifiedMethod() = default; 45 46 const std::vector<uint8_t>& GetDexGcMap() const { 47 return dex_gc_map_; 48 } 49 50 const DevirtualizationMap& GetDevirtMap() const { 51 return devirt_map_; 52 } 53 54 const SafeCastSet& GetSafeCastSet() const { 55 return safe_cast_set_; 56 } 57 58 // Returns the devirtualization target method, or nullptr if none. 59 const MethodReference* GetDevirtTarget(uint32_t dex_pc) const; 60 61 // Returns true if the cast can statically be verified to be redundant 62 // by using the check-cast elision peephole optimization in the verifier. 63 bool IsSafeCast(uint32_t pc) const; 64 65 private: 66 VerifiedMethod() = default; 67 68 /* 69 * Generate the GC map for a method that has just been verified (i.e. we're doing this as part of 70 * verification). For type-precise determination we have all the data we need, so we just need to 71 * encode it in some clever fashion. 72 * Stores the data in dex_gc_map_, returns true on success and false on failure. 73 */ 74 bool GenerateGcMap(verifier::MethodVerifier* method_verifier); 75 76 // Verify that the GC map associated with method_ is well formed. 77 static void VerifyGcMap(verifier::MethodVerifier* method_verifier, 78 const std::vector<uint8_t>& data); 79 80 // Compute sizes for GC map data. 81 static void ComputeGcMapSizes(verifier::MethodVerifier* method_verifier, 82 size_t* gc_points, size_t* ref_bitmap_bits, size_t* log2_max_gc_pc); 83 84 // Generate devirtualizaion map into devirt_map_. 85 void GenerateDevirtMap(verifier::MethodVerifier* method_verifier) 86 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 87 88 // Generate safe case set into safe_cast_set_. 89 void GenerateSafeCastSet(verifier::MethodVerifier* method_verifier) 90 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 91 92 std::vector<uint8_t> dex_gc_map_; 93 DevirtualizationMap devirt_map_; 94 SafeCastSet safe_cast_set_; 95 }; 96 97 } // namespace art 98 99 #endif // ART_COMPILER_DEX_VERIFIED_METHOD_H_ 100
