Vladimir Marko | b163bb7 | 2015-03-31 21:49:49 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2015 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_LINKER_RELATIVE_PATCHER_H_ |
| 18 | #define ART_COMPILER_LINKER_RELATIVE_PATCHER_H_ |
| 19 | |
| 20 | #include <vector> |
| 21 | |
| 22 | #include "arch/instruction_set.h" |
| 23 | #include "arch/instruction_set_features.h" |
| 24 | #include "base/macros.h" |
| 25 | #include "method_reference.h" |
| 26 | #include "utils/array_ref.h" |
| 27 | |
| 28 | namespace art { |
| 29 | |
| 30 | class CompiledMethod; |
| 31 | class LinkerPatch; |
| 32 | class OutputStream; |
| 33 | |
| 34 | namespace linker { |
| 35 | |
| 36 | /** |
| 37 | * @class RelativePatcherTargetProvider |
| 38 | * @brief Interface for providing method offsets for relative call targets. |
| 39 | */ |
| 40 | class RelativePatcherTargetProvider { |
| 41 | public: |
| 42 | /** |
| 43 | * Find the offset of the target method of a relative call if known. |
| 44 | * |
| 45 | * The process of assigning target method offsets includes calls to the relative patcher's |
| 46 | * ReserveSpace() which in turn can use FindMethodOffset() to determine if a method already |
| 47 | * has an offset assigned and, if so, what's that offset. If the offset has not yet been |
| 48 | * assigned or if it's too far for the particular architecture's relative call, |
| 49 | * ReserveSpace() may need to allocate space for a special dispatch thunk. |
| 50 | * |
| 51 | * @param ref the target method of the relative call. |
| 52 | * @return true in the first element of the pair if the method was found, false otherwise; |
| 53 | * if found, the second element specifies the offset. |
| 54 | */ |
| 55 | virtual std::pair<bool, uint32_t> FindMethodOffset(MethodReference ref) = 0; |
| 56 | |
| 57 | protected: |
| 58 | virtual ~RelativePatcherTargetProvider() { } |
| 59 | }; |
| 60 | |
| 61 | /** |
| 62 | * @class RelativePatcher |
| 63 | * @brief Interface for architecture-specific link-time patching of PC-relative references. |
| 64 | */ |
| 65 | class RelativePatcher { |
| 66 | public: |
| 67 | static std::unique_ptr<RelativePatcher> Create( |
| 68 | InstructionSet instruction_set, const InstructionSetFeatures* features, |
| 69 | RelativePatcherTargetProvider* provider); |
| 70 | |
| 71 | virtual ~RelativePatcher() { } |
| 72 | |
| 73 | uint32_t CodeAlignmentSize() const { |
| 74 | return size_code_alignment_; |
| 75 | } |
| 76 | |
| 77 | uint32_t RelativeCallThunksSize() const { |
| 78 | return size_relative_call_thunks_; |
| 79 | } |
| 80 | |
| 81 | uint32_t MiscThunksSize() const { |
| 82 | return size_misc_thunks_; |
| 83 | } |
| 84 | |
| 85 | // Reserve space for relative call thunks if needed, return adjusted offset. After all methods |
| 86 | // of a class have been processed it's called one last time with compiled_method == nullptr. |
| 87 | virtual uint32_t ReserveSpace(uint32_t offset, const CompiledMethod* compiled_method) = 0; |
| 88 | |
| 89 | // Write relative call thunks if needed, return adjusted offset. |
| 90 | virtual uint32_t WriteThunks(OutputStream* out, uint32_t offset) = 0; |
| 91 | |
| 92 | // Patch method code. The input displacement is relative to the patched location, |
| 93 | // the patcher may need to adjust it if the correct base is different. |
| 94 | virtual void PatchCall(std::vector<uint8_t>* code, uint32_t literal_offset, |
| 95 | uint32_t patch_offset, uint32_t target_offset) = 0; |
| 96 | |
| 97 | // Patch a reference to a dex cache location. |
| 98 | virtual void PatchDexCacheReference(std::vector<uint8_t>* code, const LinkerPatch& patch, |
| 99 | uint32_t patch_offset, uint32_t target_offset) = 0; |
| 100 | |
| 101 | protected: |
| 102 | RelativePatcher() |
| 103 | : size_code_alignment_(0u), |
| 104 | size_relative_call_thunks_(0u), |
| 105 | size_misc_thunks_(0u) { |
| 106 | } |
| 107 | |
| 108 | bool WriteCodeAlignment(OutputStream* out, uint32_t aligned_code_delta); |
| 109 | bool WriteRelCallThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk); |
| 110 | bool WriteMiscThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk); |
| 111 | |
| 112 | private: |
| 113 | uint32_t size_code_alignment_; |
| 114 | uint32_t size_relative_call_thunks_; |
| 115 | uint32_t size_misc_thunks_; |
| 116 | |
| 117 | DISALLOW_COPY_AND_ASSIGN(RelativePatcher); |
| 118 | }; |
| 119 | |
| 120 | } // namespace linker |
| 121 | } // namespace art |
| 122 | |
| 123 | #endif // ART_COMPILER_LINKER_RELATIVE_PATCHER_H_ |