Add EH frame and debug frame support.

Bug: 23762183

Test: Pass new unit tests.
Change-Id: I1bfe900e068017ff31998f359bf98d4c5c9af2a5
diff --git a/libunwindstack/DwarfDebugFrame.h b/libunwindstack/DwarfDebugFrame.h
new file mode 100644
index 0000000..320368c
--- /dev/null
+++ b/libunwindstack/DwarfDebugFrame.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2017 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 _LIBUNWINDSTACK_DWARF_DEBUG_FRAME_H
+#define _LIBUNWINDSTACK_DWARF_DEBUG_FRAME_H
+
+#include <stdint.h>
+
+#include <vector>
+
+#include "DwarfSection.h"
+
+template <typename AddressType>
+class DwarfDebugFrame : public DwarfSectionImpl<AddressType> {
+ public:
+  // Add these so that the protected members of DwarfSectionImpl
+  // can be accessed without needing a this->.
+  using DwarfSectionImpl<AddressType>::memory_;
+  using DwarfSectionImpl<AddressType>::fde_count_;
+  using DwarfSectionImpl<AddressType>::last_error_;
+
+  struct FdeInfo {
+    FdeInfo(uint64_t offset, uint64_t start, uint64_t length)
+        : offset(offset), start(start), end(start + length) {}
+
+    uint64_t offset;
+    AddressType start;
+    AddressType end;
+  };
+
+  DwarfDebugFrame(Memory* memory) : DwarfSectionImpl<AddressType>(memory) {}
+  virtual ~DwarfDebugFrame() = default;
+
+  bool Init(uint64_t offset, uint64_t size) override;
+
+  bool GetFdeOffsetFromPc(uint64_t pc, uint64_t* fde_offset) override;
+
+  const DwarfFde* GetFdeFromIndex(size_t index) override;
+
+  bool IsCie32(uint32_t value32) override { return value32 == static_cast<uint32_t>(-1); }
+
+  bool IsCie64(uint64_t value64) override { return value64 == static_cast<uint64_t>(-1); }
+
+  uint64_t GetCieOffsetFromFde32(uint32_t pointer) override { return offset_ + pointer; }
+
+  uint64_t GetCieOffsetFromFde64(uint64_t pointer) override { return offset_ + pointer; }
+
+  uint64_t AdjustPcFromFde(uint64_t pc) override { return pc; }
+
+  bool GetCieInfo(uint8_t* segment_size, uint8_t* encoding);
+
+  bool AddFdeInfo(uint64_t entry_offset, uint8_t segment_size, uint8_t encoding);
+
+  bool CreateSortedFdeList();
+
+ protected:
+  uint64_t offset_;
+  uint64_t end_offset_;
+
+  std::vector<FdeInfo> fdes_;
+};
+
+#endif  // _LIBUNWINDSTACK_DWARF_DEBUG_FRAME_H