Add Symbols parsing.

Bug: 23762183

Test: New unit tests pass.
Change-Id: Ib67fee879120b5e82889076a0f7221dc429ac140
diff --git a/libunwindstack/Symbols.h b/libunwindstack/Symbols.h
new file mode 100644
index 0000000..3c0d033
--- /dev/null
+++ b/libunwindstack/Symbols.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2016 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_SYMBOLS_H
+#define _LIBUNWINDSTACK_SYMBOLS_H
+
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+// Forward declaration.
+class Memory;
+
+class Symbols {
+  struct Info {
+    Info(uint64_t start_offset, uint64_t end_offset, uint64_t str_offset)
+        : start_offset(start_offset), end_offset(end_offset), str_offset(str_offset) {}
+    uint64_t start_offset;
+    uint64_t end_offset;
+    uint64_t str_offset;
+  };
+
+ public:
+  Symbols(uint64_t offset, uint64_t size, uint64_t entry_size, uint64_t str_offset,
+          uint64_t str_size);
+  virtual ~Symbols() = default;
+
+  const Info* GetInfoFromCache(uint64_t addr);
+
+  template <typename SymType>
+  bool GetName(uint64_t addr, uint64_t load_bias, Memory* elf_memory, std::string* name,
+               uint64_t* func_offset);
+
+  void ClearCache() {
+    symbols_.clear();
+    cur_offset_ = offset_;
+  }
+
+ private:
+  uint64_t cur_offset_;
+  uint64_t offset_;
+  uint64_t end_;
+  uint64_t entry_size_;
+  uint64_t str_offset_;
+  uint64_t str_end_;
+
+  std::vector<Info> symbols_;
+};
+
+#endif  // _LIBUNWINDSTACK_SYMBOLS_H