| # Copyright 2026 The Chromium Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| """A demangler relying on the in-tree tool llvm-cxxfilt.""" |
| |
| import os |
| import pathlib |
| import subprocess |
| |
| |
| class Demangler: |
| """Demangles line by line. |
| |
| For simplicity, ignores stderr and can block forever if the external |
| command does not return. |
| """ |
| |
| def __init__(self): |
| src_path = pathlib.Path(__file__).resolve().parents[4] |
| self.binary_path = str( |
| src_path / |
| 'third_party/llvm-build/Release+Asserts/bin/llvm-cxxfilt') |
| self.process = None |
| |
| def start(self): |
| if not os.path.exists(self.binary_path): |
| raise FileNotFoundError(f'Not found: {self.binary_path}') |
| # TODO(crbug.com/473768497): Explore async demangling. |
| self.process = subprocess.Popen([self.binary_path], |
| stdin=subprocess.PIPE, |
| stdout=subprocess.PIPE, |
| stderr=subprocess.DEVNULL, |
| text=True, |
| bufsize=1) |
| |
| def demangle(self, mangled_name): |
| if not self.process: |
| raise RuntimeError('Process not started') |
| |
| try: |
| self.process.stdin.write(mangled_name + '\n') |
| self.process.stdin.flush() |
| |
| result = self.process.stdout.readline() |
| return result.strip() |
| except (BrokenPipeError, IOError): |
| raise RuntimeError('Error: Process closed unexpectedly') |
| |
| def stop(self): |
| if self.process: |
| self.process.stdin.close() |
| self.process.stdout.close() |
| self.process.wait() |
| self.process = None |
| |
| def __enter__(self): |
| self.start() |
| return self |
| |
| def __exit__(self, exc_type, exc_val, exc_tb): |
| self.stop() |
