unplugged-system/build/bazel/scripts/difftool/diffs/nm.py

94 lines
3.2 KiB
Python

#!/usr/bin/env python3
#
# Copyright (C) 2022 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."""
import pathlib
import re
import subprocess
from diffs.diff import Diff, ExtractInfo
class _Symbol:
"""Data structure to hold a symbol as specified by nm
Equality of symbols is based on their name and attributes.
The self._addr property is excluded from comparisons in this class
because the location of a symbol in one binary is not a useful
difference from another binary.
"""
def __init__(self, name, addr, attr):
self.name = name
self._addr = addr
self.attr = attr
def __hash__(self):
return (self.name + self.attr).__hash__()
def __eq__(self, other):
return self.name == other.name and self.attr == other.attr
def __repr__(self):
return f"{self.name}{{{self.attr}}}"
class NmSymbolDiff(Diff):
"""Compares symbols the symbol table output by nm
Example nm output:
0000000000000140 t GetExceptionSummary
U ExpandableStringInitialize
U ExpandableStringRelease
0000000000000cf0 T jniCreateString
The first column is the address of the symbol in the binary, the second
column is an attribute associated with the symbol (see man nm for details),
and the last column is the demangled symbol name.
"""
_nm_re = re.compile(r"^(\w+)?\s+([a-zA-Z])\s(\S+)$")
def __init__(self, tool: ExtractInfo, tool_name: str):
self.tool = tool
self.tool_name = tool_name
def _read_symbols(nm_output):
symbols = set()
for line in nm_output:
match = NmSymbolDiff._nm_re.match(line)
if match:
symbols.add(_Symbol(match.group(3), match.group(1), match.group(2)))
return symbols
def diff(self, left_path: pathlib.Path, right_path: pathlib.Path) -> list[str]:
left_nm = subprocess.run(["nm", left_path], capture_output=True, encoding="utf-8").stdout.splitlines()
right_nm = subprocess.run(["nm", right_path], capture_output=True, encoding="utf-8").stdout.splitlines()
left_symbols = NmSymbolDiff._read_symbols(left_nm)
right_symbols = NmSymbolDiff._read_symbols(right_nm)
left_only = []
for s in left_symbols:
if s not in right_symbols:
left_only.append(s)
right_only = []
for s in right_symbols:
if s not in left_symbols:
right_only.append(s)
errors = []
if left_only:
errors.append(f"symbols in {left_path} not in {right_path}:")
errors.extend("\t" + str(s) for s in left_only)
if right_only:
errors.append(f"symbols in {right_path} not in {left_path}:")
errors.extend("\t" + str(s) for s in right_only)
return errors