upload android base code part3

android/art/compiler/linker/relative_patcher.h

@@ -0,0 +1,139 @@
+/*
+ * 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_RELATIVE_PATCHER_H_
+#define ART_COMPILER_LINKER_RELATIVE_PATCHER_H_
+
+#include <vector>
+
+#include "arch/instruction_set.h"
+#include "arch/instruction_set_features.h"
+#include "base/array_ref.h"
+#include "base/macros.h"
+#include "method_reference.h"
+
+namespace art {
+
+class CompiledMethod;
+class LinkerPatch;
+class OutputStream;
+
+namespace linker {
+
+/**
+ * @class RelativePatcherTargetProvider
+ * @brief Interface for providing method offsets for relative call targets.
+ */
+class RelativePatcherTargetProvider {
+ public:
+  /**
+   * Find the offset of the target method of a relative call if known.
+   *
+   * The process of assigning target method offsets includes calls to the relative patcher's
+   * ReserveSpace() which in turn can use FindMethodOffset() to determine if a method already
+   * has an offset assigned and, if so, what's that offset. If the offset has not yet been
+   * assigned or if it's too far for the particular architecture's relative call,
+   * ReserveSpace() may need to allocate space for a special dispatch thunk.
+   *
+   * @param ref the target method of the relative call.
+   * @return true in the first element of the pair if the method was found, false otherwise;
+   *         if found, the second element specifies the offset.
+   */
+  virtual std::pair<bool, uint32_t> FindMethodOffset(MethodReference ref) = 0;
+
+ protected:
+  virtual ~RelativePatcherTargetProvider() { }
+};
+
+/**
+ * @class RelativePatcher
+ * @brief Interface for architecture-specific link-time patching of PC-relative references.
+ */
+class RelativePatcher {
+ public:
+  static std::unique_ptr<RelativePatcher> Create(
+      InstructionSet instruction_set, const InstructionSetFeatures* features,
+      RelativePatcherTargetProvider* provider);
+
+  virtual ~RelativePatcher() { }
+
+  uint32_t CodeAlignmentSize() const {
+    return size_code_alignment_;
+  }
+
+  uint32_t RelativeCallThunksSize() const {
+    return size_relative_call_thunks_;
+  }
+
+  uint32_t MiscThunksSize() const {
+    return size_misc_thunks_;
+  }
+
+  // Reserve space for thunks if needed before a method, return adjusted offset.
+  virtual uint32_t ReserveSpace(uint32_t offset,
+                                const CompiledMethod* compiled_method,
+                                MethodReference method_ref) = 0;
+
+  // Reserve space for thunks if needed after the last method, return adjusted offset.
+  // The caller may use this method to preemptively force thunk space reservation and
+  // then resume reservation for more methods. This is useful when there is a gap in
+  // the .text segment, for example when going to the next oat file for multi-image.
+  virtual uint32_t ReserveSpaceEnd(uint32_t offset) = 0;
+
+  // Write relative call thunks if needed, return adjusted offset. Returns 0 on write failure.
+  virtual uint32_t WriteThunks(OutputStream* out, uint32_t offset) = 0;
+
+  // Patch method code. The input displacement is relative to the patched location,
+  // the patcher may need to adjust it if the correct base is different.
+  virtual void PatchCall(std::vector<uint8_t>* code,
+                         uint32_t literal_offset,
+                         uint32_t patch_offset,
+                         uint32_t target_offset) = 0;
+
+  // Patch a reference to a dex cache location.
+  virtual void PatchPcRelativeReference(std::vector<uint8_t>* code,
+                                        const LinkerPatch& patch,
+                                        uint32_t patch_offset,
+                                        uint32_t target_offset) = 0;
+
+  // Patch a branch to a Baker read barrier thunk.
+  virtual void PatchBakerReadBarrierBranch(std::vector<uint8_t>* code,
+                                           const LinkerPatch& patch,
+                                           uint32_t patch_offset) = 0;
+
+ protected:
+  RelativePatcher()
+      : size_code_alignment_(0u),
+        size_relative_call_thunks_(0u),
+        size_misc_thunks_(0u) {
+  }
+
+  bool WriteCodeAlignment(OutputStream* out, uint32_t aligned_code_delta);
+  bool WriteThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk);
+  bool WriteMiscThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk);
+
+ private:
+  uint32_t size_code_alignment_;
+  uint32_t size_relative_call_thunks_;
+  uint32_t size_misc_thunks_;
+
+  DISALLOW_COPY_AND_ASSIGN(RelativePatcher);
+};
+
+}  // namespace linker
+}  // namespace art
+
+#endif  // ART_COMPILER_LINKER_RELATIVE_PATCHER_H_