--- /dev/null	2020-03-11 13:09:53.631238700 +0900
+++ new/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp	2020-03-11 14:46:07.289546700 +0900
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, NTT DATA.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef _DWARF_HPP_
+#define _DWARF_HPP_
+
+#include "libproc_impl.h"
+
+/*
+ * from System V Application Binary Interface
+ *        AMD64 Architecture Processor Supplement
+ *          Figure 3.38: DWARF Register Number Mapping
+ * https://software.intel.com/sites/default/files/article/402129/mpx-linux64-abi.pdf
+ */
+enum DWARF_Register {
+  RAX,
+  RDX,
+  RCX,
+  RBX,
+  RSI,
+  RDI,
+  RBP,
+  RSP,
+  R8,
+  R9,
+  R10,
+  R11,
+  R12,
+  R13,
+  R14,
+  R15,
+  RA,
+  MAX_VALUE
+};
+
+/*
+ * DwarfParser finds out CFA (Canonical Frame Address) from DWARF in ELF binary.
+ * Also Return Address (RA) and Base Pointer (BP) are calculated from CFA.
+ */
+class DwarfParser {
+  private:
+    const lib_info *_lib;
+    unsigned char *_buf;
+    unsigned char _encoding;
+    enum DWARF_Register _cfa_reg;
+    enum DWARF_Register _return_address_reg;
+    unsigned int _code_factor;
+    int _data_factor;
+
+    uintptr_t _current_pc;
+    int _cfa_offset;
+    int _ra_cfa_offset;
+    int _bp_cfa_offset;
+    bool _bp_offset_available;
+
+    uintptr_t read_leb(bool sign);
+    uint64_t get_entry_length();
+    void process_cie(unsigned char *start_of_entry, uint32_t id);
+    void parse_dwarf_instructions(uintptr_t begin, uintptr_t pc, const unsigned char *end);
+    uint32_t get_decoded_value();
+    unsigned int get_pc_range();
+
+  public:
+    DwarfParser(lib_info *lib) : _lib(lib),
+                                 _buf(NULL),
+                                 _encoding(0),
+                                 _cfa_reg(RSP),
+                                 _return_address_reg(RA),
+                                 _code_factor(0),
+                                 _data_factor(0),
+                                 _current_pc(0L),
+                                 _cfa_offset(0),
+                                 _ra_cfa_offset(0),
+                                 _bp_cfa_offset(0),
+                                 _bp_offset_available(false) {};
+
+    ~DwarfParser() {}
+    uintptr_t process_dwarf(const uintptr_t pc);
+    enum DWARF_Register get_cfa_register() { return _cfa_reg; }
+    int get_cfa_offset() { return _cfa_offset; }
+    int get_ra_cfa_offset() { return _ra_cfa_offset; }
+    int get_bp_cfa_offset() { return _bp_cfa_offset; }
+    bool is_bp_offset_available() { return _bp_offset_available; }
+
+    bool is_in(long pc) {
+      return (_lib->exec_start <= pc) && (pc < _lib->exec_end);
+    }
+
+    bool is_parseable() {
+      return _lib->eh_frame.data != NULL;
+    }
+};
+
+#endif //_DWARF_HPP_