1#!/usr/bin/env python3 2# 3# Copyright (C) 2022 The Android Open Source Project 4# 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8# 9# http://www.apache.org/licenses/LICENSE-2.0 10# 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License.""" 16 17import pathlib 18import re 19import subprocess 20from diffs.diff import Diff, ExtractInfo 21 22class _Symbol: 23 """Data structure to hold a symbol as specified by nm 24 25 Equality of symbols is based on their name and attributes. 26 27 The self._addr property is excluded from comparisons in this class 28 because the location of a symbol in one binary is not a useful 29 difference from another binary. 30 """ 31 def __init__(self, name, addr, attr): 32 self.name = name 33 self._addr = addr 34 self.attr = attr 35 def __hash__(self): 36 return (self.name + self.attr).__hash__() 37 def __eq__(self, other): 38 return self.name == other.name and self.attr == other.attr 39 def __repr__(self): 40 return f"{self.name}{{{self.attr}}}" 41 42 43class NmSymbolDiff(Diff): 44 """Compares symbols the symbol table output by nm 45 46 Example nm output: 47 0000000000000140 t GetExceptionSummary 48 U ExpandableStringInitialize 49 U ExpandableStringRelease 50 0000000000000cf0 T jniCreateString 51 52 The first column is the address of the symbol in the binary, the second 53 column is an attribute associated with the symbol (see man nm for details), 54 and the last column is the demangled symbol name. 55 """ 56 _nm_re = re.compile(r"^(\w+)?\s+([a-zA-Z])\s(\S+)$") 57 58 def __init__(self, tool: ExtractInfo, tool_name: str): 59 self.tool = tool 60 self.tool_name = tool_name 61 62 def _read_symbols(nm_output): 63 symbols = set() 64 for line in nm_output: 65 match = NmSymbolDiff._nm_re.match(line) 66 if match: 67 symbols.add(_Symbol(match.group(3), match.group(1), match.group(2))) 68 return symbols 69 70 def diff(self, left_path: pathlib.Path, right_path: pathlib.Path) -> list[str]: 71 left_nm = subprocess.run(["nm", left_path], capture_output=True, encoding="utf-8").stdout.splitlines() 72 right_nm = subprocess.run(["nm", right_path], capture_output=True, encoding="utf-8").stdout.splitlines() 73 left_symbols = NmSymbolDiff._read_symbols(left_nm) 74 right_symbols = NmSymbolDiff._read_symbols(right_nm) 75 76 left_only = [] 77 for s in left_symbols: 78 if s not in right_symbols: 79 left_only.append(s) 80 right_only = [] 81 for s in right_symbols: 82 if s not in left_symbols: 83 right_only.append(s) 84 85 errors = [] 86 if left_only: 87 errors.append(f"symbols in {left_path} not in {right_path}:") 88 errors.extend("\t" + str(s) for s in left_only) 89 if right_only: 90 errors.append(f"symbols in {right_path} not in {left_path}:") 91 errors.extend("\t" + str(s) for s in right_only) 92 93 return errors 94