Refactor RelativePatcher out of OatWriter.

Move the relative patcher classes to compiler/linker/ and
compiler/linker/<arch>/ . Refactor them to avoid OatWriter
dependency so that they can be unit tested. Add tests for
x86 and x86-64.

Change-Id: I1b42baa9fc431378e4cce1399bec590c5b5a409f
diff --git a/compiler/linker/arm64/relative_patcher_arm64.h b/compiler/linker/arm64/relative_patcher_arm64.h
new file mode 100644
index 0000000..f8c6802
--- /dev/null
+++ b/compiler/linker/arm64/relative_patcher_arm64.h
@@ -0,0 +1,72 @@
+/*
+ * 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_ARM64_RELATIVE_PATCHER_ARM64_H_
+#define ART_COMPILER_LINKER_ARM64_RELATIVE_PATCHER_ARM64_H_
+
+#include "linker/arm/relative_patcher_arm_base.h"
+#include "utils/array_ref.h"
+
+namespace art {
+namespace linker {
+
+class Arm64RelativePatcher FINAL : public ArmBaseRelativePatcher {
+ public:
+  Arm64RelativePatcher(RelativePatcherTargetProvider* provider,
+                       const Arm64InstructionSetFeatures* features);
+
+  uint32_t ReserveSpace(uint32_t offset, const CompiledMethod* compiled_method) OVERRIDE;
+  uint32_t WriteThunks(OutputStream* out, uint32_t offset) OVERRIDE;
+  void PatchCall(std::vector<uint8_t>* code, uint32_t literal_offset,
+                 uint32_t patch_offset, uint32_t target_offset) OVERRIDE;
+  void PatchDexCacheReference(std::vector<uint8_t>* code, const LinkerPatch& patch,
+                              uint32_t patch_offset, uint32_t target_offset) OVERRIDE;
+
+ private:
+  static std::vector<uint8_t> CompileThunkCode();
+  static uint32_t PatchAdrp(uint32_t adrp, uint32_t disp);
+
+  static bool NeedsErratum843419Thunk(ArrayRef<const uint8_t> code, uint32_t literal_offset,
+                                      uint32_t patch_offset);
+  void SetInsn(std::vector<uint8_t>* code, uint32_t offset, uint32_t value);
+  static uint32_t GetInsn(ArrayRef<const uint8_t> code, uint32_t offset);
+
+  template <typename Alloc>
+  static uint32_t GetInsn(std::vector<uint8_t, Alloc>* code, uint32_t offset);
+
+  // Maximum positive and negative displacement measured from the patch location.
+  // (Signed 28 bit displacement with the last bit 0 has range [-2^27, 2^27-4] measured from
+  // the ARM64 PC pointing to the BL.)
+  static constexpr uint32_t kMaxPositiveDisplacement = (1u << 27) - 4u;
+  static constexpr uint32_t kMaxNegativeDisplacement = (1u << 27);
+
+  // The ADRP thunk for erratum 843419 is 2 instructions, i.e. 8 bytes.
+  static constexpr uint32_t kAdrpThunkSize = 8u;
+
+  const bool fix_cortex_a53_843419_;
+  // Map original patch_offset to thunk offset.
+  std::vector<std::pair<uint32_t, uint32_t>> adrp_thunk_locations_;
+  size_t reserved_adrp_thunks_;
+  size_t processed_adrp_thunks_;
+  std::vector<uint8_t> current_method_thunks_;
+
+  DISALLOW_COPY_AND_ASSIGN(Arm64RelativePatcher);
+};
+
+}  // namespace linker
+}  // namespace art
+
+#endif  // ART_COMPILER_LINKER_ARM64_RELATIVE_PATCHER_ARM64_H_