diff --git a/tools/show_vtable.py b/tools/show_vtable.py new file mode 100755 index 00000000..ef06b3ee --- /dev/null +++ b/tools/show_vtable.py @@ -0,0 +1,115 @@ +#!/usr/bin/env python3 + +import argparse +from colorama import Fore, Style +import cxxfilt +from elftools.elf.elffile import ELFFile +import diff_settings +from pathlib import Path +import struct +from typing import Any, Dict, Optional +import utils + +config: Dict[str, Any] = {} +diff_settings.apply(config, {}) + +root = Path(__file__).parent.parent +my_elf = ELFFile((root / config["myimg"]).open("rb")) +my_symtab = my_elf.get_section_by_name(".symtab") +if not my_symtab: + utils.fail(f'{config["myimg"]} has no symbol table') + + +def get_file_offset(elf, addr: int) -> int: + for seg in elf.iter_segments(): + if seg.header["p_type"] != "PT_LOAD": + continue + if seg["p_vaddr"] <= addr < seg["p_vaddr"] + seg["p_filesz"]: + return addr - seg["p_vaddr"] + seg["p_offset"] + assert False + + +def get_symbol_file_offset_and_size(elf, table, name: str) -> (int, int): + syms = table.get_symbol_by_name(name) + if not syms or len(syms) != 1: + raise KeyError(name) + return get_file_offset(elf, syms[0]["st_value"]), syms[0]["st_size"] + + +def build_symbol_table(symtab) -> Dict[int, str]: + table = dict() + for sym in symtab.iter_symbols(): + addr = sym["st_value"] + existing_value = table.get(addr, None) + if existing_value is None or not existing_value.startswith("_Z"): + table[addr] = sym.name + return table + + +def find_vtable(symtab, class_name: str) -> Optional[str]: + OFFSET = len("vtable for ") + for sym in symtab.iter_symbols(): + if not sym.name.startswith("_ZTV"): + continue + if cxxfilt.demangle(sym.name)[OFFSET:] == class_name: + return sym.name + return None + + +def bold(s) -> str: + return Style.BRIGHT + str(s) + Style.NORMAL + + +def dump_table(name: str) -> None: + try: + symbols = build_symbol_table(my_symtab) + decomp_symbols = {fn.decomp_name for fn in utils.get_functions() if fn.decomp_name} + + offset, size = get_symbol_file_offset_and_size(my_elf, my_symtab, name) + my_elf.stream.seek(offset) + vtable_bytes = my_elf.stream.read(size) + + if not vtable_bytes: + utils.fail( + "empty vtable; has the key function been implemented? (https://lld.llvm.org/missingkeyfunction.html)") + + print(f"{Fore.WHITE}{Style.BRIGHT}{cxxfilt.demangle(name)}{Style.RESET_ALL}") + print(f"{Fore.YELLOW}{Style.BRIGHT}vtable @ 0x0{Style.RESET_ALL}") + + assert size % 8 == 0 + for i in range(size // 8): + word: int = struct.unpack_from(" None: + parser = argparse.ArgumentParser() + parser.add_argument("symbol_name", help="Name of the vtable symbol (_ZTV...) or class name") + args = parser.parse_args() + + symbol_name: str = args.symbol_name + + if not symbol_name.startswith("_ZTV"): + symbol_name = find_vtable(my_symtab, args.symbol_name) + + dump_table(symbol_name) + + +if __name__ == "__main__": + main()