/*
* Copyright (C) 2015 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.
*/
#ifndef ART_COMPILER_LINKER_ARM_RELATIVE_PATCHER_THUMB2_H_
#define ART_COMPILER_LINKER_ARM_RELATIVE_PATCHER_THUMB2_H_
#include "linker/arm/relative_patcher_arm_base.h"
namespace art {
namespace linker {
class Thumb2RelativePatcher FINAL : public ArmBaseRelativePatcher {
public:
explicit Thumb2RelativePatcher(RelativePatcherTargetProvider* provider);
void PatchCall(std::vector<uint8_t>* code,
uint32_t literal_offset,
uint32_t patch_offset,
uint32_t target_offset) OVERRIDE;
void PatchPcRelativeReference(std::vector<uint8_t>* code,
const LinkerPatch& patch,
uint32_t patch_offset,
uint32_t target_offset) OVERRIDE;
private:
static std::vector<uint8_t> CompileThunkCode();
void SetInsn32(std::vector<uint8_t>* code, uint32_t offset, uint32_t value);
static uint32_t GetInsn32(ArrayRef<const uint8_t> code, uint32_t offset);
template <typename Vector>
static uint32_t GetInsn32(Vector* code, uint32_t offset);
// PC displacement from patch location; Thumb2 PC is always at instruction address + 4.
static constexpr int32_t kPcDisplacement = 4;
// Maximum positive and negative displacement measured from the patch location.
// (Signed 25 bit displacement with the last bit 0 has range [-2^24, 2^24-2] measured from
// the Thumb2 PC pointing right after the BL, i.e. 4 bytes later than the patch location.)
static constexpr uint32_t kMaxPositiveDisplacement = (1u << 24) - 2 + kPcDisplacement;
static constexpr uint32_t kMaxNegativeDisplacement = (1u << 24) - kPcDisplacement;
DISALLOW_COPY_AND_ASSIGN(Thumb2RelativePatcher);
};
} // namespace linker
} // namespace art
#endif // ART_COMPILER_LINKER_ARM_RELATIVE_PATCHER_THUMB2_H_