Add the Dwarf CFA handling.

Bug: 23762183

Test: Ran new unit tests.
Change-Id: I31abac1238cc671b78a505da655fb6298be072b4
diff --git a/libunwindstack/DwarfStructs.h b/libunwindstack/DwarfStructs.h
new file mode 100644
index 0000000..57aac88
--- /dev/null
+++ b/libunwindstack/DwarfStructs.h
@@ -0,0 +1,52 @@
+/*
+ * 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_DWARF_STRUCTS_H
+#define _LIBUNWINDSTACK_DWARF_STRUCTS_H
+
+#include <stdint.h>
+
+#include <vector>
+
+#include "DwarfEncoding.h"
+
+struct DwarfCIE {
+  uint8_t version = 0;
+  uint8_t fde_address_encoding = DW_EH_PE_absptr;
+  uint8_t lsda_encoding = DW_EH_PE_omit;
+  uint8_t segment_size = 0;
+  std::vector<char> augmentation_string;
+  uint64_t personality_handler = 0;
+  uint64_t cfa_instructions_offset = 0;
+  uint64_t cfa_instructions_end = 0;
+  uint64_t code_alignment_factor = 0;
+  int64_t data_alignment_factor = 0;
+  uint64_t return_address_register = 0;
+};
+
+struct DwarfFDE {
+  uint64_t cie_offset = 0;
+  uint64_t cfa_instructions_offset = 0;
+  uint64_t cfa_instructions_end = 0;
+  uint64_t pc_start = 0;
+  uint64_t pc_end = 0;
+  uint64_t lsda_address = 0;
+  const DwarfCIE* cie = nullptr;
+};
+
+constexpr uint16_t CFA_REG = static_cast<uint16_t>(-1);
+
+#endif  // _LIBUNWINDSTACK_DWARF_STRUCTS_H