#!/usr/bin/env python3

# Copyright (C) 2024-2025 Free Software Foundation, Inc.
# Contributed by Timur Golubovich

# This file is part of GDB.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.

# This program 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 for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


# To get help message for this script, run:
# ./gdb/syscalls/riscv-linux-canonicalize-syscall-gen.py --help

# Execution result:

# usage: riscv-linux-canonicalize-syscall-gen.py [-h]
#
# Generate file gdb/riscv-linux-canonicalize-syscall-gen.c from
# gdb/syscalls/riscv-linux.xml.
#
# options:
#   -h, --help            show this help message and exit

import argparse
import re
import xml.etree.ElementTree as ET
from pathlib import Path

FILE = Path(__file__).resolve()

HEAD = f"""\
/* DO NOT EDIT: Autogenerated by {FILE.name}

   Copyright (C) 2024-2025 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program 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 for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "riscv-linux-tdep.h"

/* riscv_linux_canonicalize_syscall maps from the native RISC-V Linux set
   of syscall ids into a canonical set of syscall ids used by
   process record.  */

enum gdb_syscall
riscv_linux_canonicalize_syscall (int syscall)
{{
  switch (syscall)
    {{
"""

TAIL = """\
    default:
      return gdb_sys_no_syscall;
    }
}
"""

HELP_MESSAGE = """\
Generate file gdb/riscv-linux-canonicalize-syscall-gen.c from
gdb/syscalls/riscv-linux.xml.
"""


class Generator:
    def _get_gdb_syscalls(self, gdb_syscalls_path: Path) -> set[str]:
        gdb_syscalls = set[str]()
        with open(gdb_syscalls_path, "r", encoding="UTF-8") as file:
            for line in file:
                match = re.search(r"(gdb_sys_\S+)\s*=", line)
                if match:
                    gdb_syscalls.add(match[1].strip())
        return gdb_syscalls

    def _get_arch_syscalls(self, xml_syscalls_path: Path) -> dict[str, int]:
        arch_syscalls: dict[str, int] = {}
        syscalls_info = ET.parse(xml_syscalls_path)
        for syscall in syscalls_info.findall("syscall"):
            sysname = syscall.attrib["name"]
            sysno = int(syscall.attrib["number"])
            arch_syscalls[sysname] = sysno
        return arch_syscalls

    def _get_canon_syscalls_lines(
        self,
        arch_syscalls: dict[str, int],
        gdb_syscalls: set[str],
        exceptions: dict[str, str],
    ) -> list[str]:
        canon_syscalls: dict[int, str] = {}
        for sysname, sysno in arch_syscalls.items():
            if sysname in exceptions:
                sysname = exceptions[sysname]
            gdb_sysname = f"gdb_sys_{sysname}"
            value = f"    /* case {sysno}: return {gdb_sysname};  */\n"
            if gdb_sysname in gdb_syscalls:
                value = f"    case {sysno}: return {gdb_sysname};\n"
            canon_syscalls[sysno] = value
        return [canon_syscalls[sysno] for sysno in sorted(canon_syscalls)]

    def generate(self) -> None:
        repo_path = FILE.parent.parent.parent
        gdb_path = repo_path / "gdb"
        xml_syscalls_path = gdb_path / "syscalls" / "riscv-linux.xml"
        gdb_syscalls_path = gdb_path / "linux-record.h"
        arch_syscalls_path = gdb_path / "riscv-linux-canonicalize-syscall-gen.c"
        exceptions = {"mmap": "old_mmap"}

        arch_syscalls = self._get_arch_syscalls(xml_syscalls_path)
        gdb_syscalls = self._get_gdb_syscalls(gdb_syscalls_path)
        canon_syscalls_lines = self._get_canon_syscalls_lines(
            arch_syscalls, gdb_syscalls, exceptions
        )

        with open(arch_syscalls_path, "w", encoding="UTF-8") as file:
            file.writelines(HEAD)
            file.writelines(canon_syscalls_lines)
            file.writelines(TAIL)


def main() -> int:
    parser = argparse.ArgumentParser(description=HELP_MESSAGE)
    parser.parse_args()
    Generator().generate()
    return 0


if __name__ == "__main__":
    main()