| # -*- coding: utf-8 -*- |
| # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| # See https://llvm.org/LICENSE.txt for license information. |
| # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| """ This module compiles the intercept library. """ |
| |
| import sys |
| import os |
| import os.path |
| import re |
| import tempfile |
| import shutil |
| import contextlib |
| import logging |
| |
| __all__ = ['build_libear'] |
| |
| |
| def build_libear(compiler, dst_dir): |
| """ Returns the full path to the 'libear' library. """ |
| |
| try: |
| src_dir = os.path.dirname(os.path.realpath(__file__)) |
| toolset = make_toolset(src_dir) |
| toolset.set_compiler(compiler) |
| toolset.set_language_standard('c99') |
| toolset.add_definitions(['-D_GNU_SOURCE']) |
| |
| configure = do_configure(toolset) |
| configure.check_function_exists('execve', 'HAVE_EXECVE') |
| configure.check_function_exists('execv', 'HAVE_EXECV') |
| configure.check_function_exists('execvpe', 'HAVE_EXECVPE') |
| configure.check_function_exists('execvp', 'HAVE_EXECVP') |
| configure.check_function_exists('execvP', 'HAVE_EXECVP2') |
| configure.check_function_exists('exect', 'HAVE_EXECT') |
| configure.check_function_exists('execl', 'HAVE_EXECL') |
| configure.check_function_exists('execlp', 'HAVE_EXECLP') |
| configure.check_function_exists('execle', 'HAVE_EXECLE') |
| configure.check_function_exists('posix_spawn', 'HAVE_POSIX_SPAWN') |
| configure.check_function_exists('posix_spawnp', 'HAVE_POSIX_SPAWNP') |
| configure.check_symbol_exists('_NSGetEnviron', 'crt_externs.h', |
| 'HAVE_NSGETENVIRON') |
| configure.write_by_template( |
| os.path.join(src_dir, 'config.h.in'), |
| os.path.join(dst_dir, 'config.h')) |
| |
| target = create_shared_library('ear', toolset) |
| target.add_include(dst_dir) |
| target.add_sources('ear.c') |
| target.link_against(toolset.dl_libraries()) |
| target.link_against(['pthread']) |
| target.build_release(dst_dir) |
| |
| return os.path.join(dst_dir, target.name) |
| |
| except Exception: |
| logging.info("Could not build interception library.", exc_info=True) |
| return None |
| |
| |
| def execute(cmd, *args, **kwargs): |
| """ Make subprocess execution silent. """ |
| |
| import subprocess |
| kwargs.update({'stdout': subprocess.PIPE, 'stderr': subprocess.STDOUT}) |
| return subprocess.check_call(cmd, *args, **kwargs) |
| |
| |
| @contextlib.contextmanager |
| def TemporaryDirectory(**kwargs): |
| name = tempfile.mkdtemp(**kwargs) |
| try: |
| yield name |
| finally: |
| shutil.rmtree(name) |
| |
| |
| class Toolset(object): |
| """ Abstract class to represent different toolset. """ |
| |
| def __init__(self, src_dir): |
| self.src_dir = src_dir |
| self.compiler = None |
| self.c_flags = [] |
| |
| def set_compiler(self, compiler): |
| """ part of public interface """ |
| self.compiler = compiler |
| |
| def set_language_standard(self, standard): |
| """ part of public interface """ |
| self.c_flags.append('-std=' + standard) |
| |
| def add_definitions(self, defines): |
| """ part of public interface """ |
| self.c_flags.extend(defines) |
| |
| def dl_libraries(self): |
| raise NotImplementedError() |
| |
| def shared_library_name(self, name): |
| raise NotImplementedError() |
| |
| def shared_library_c_flags(self, release): |
| extra = ['-DNDEBUG', '-O3'] if release else [] |
| return extra + ['-fPIC'] + self.c_flags |
| |
| def shared_library_ld_flags(self, release, name): |
| raise NotImplementedError() |
| |
| |
| class DarwinToolset(Toolset): |
| def __init__(self, src_dir): |
| Toolset.__init__(self, src_dir) |
| |
| def dl_libraries(self): |
| return [] |
| |
| def shared_library_name(self, name): |
| return 'lib' + name + '.dylib' |
| |
| def shared_library_ld_flags(self, release, name): |
| extra = ['-dead_strip'] if release else [] |
| return extra + ['-dynamiclib', '-install_name', '@rpath/' + name] |
| |
| |
| class UnixToolset(Toolset): |
| def __init__(self, src_dir): |
| Toolset.__init__(self, src_dir) |
| |
| def dl_libraries(self): |
| return [] |
| |
| def shared_library_name(self, name): |
| return 'lib' + name + '.so' |
| |
| def shared_library_ld_flags(self, release, name): |
| extra = [] if release else [] |
| return extra + ['-shared', '-Wl,-soname,' + name] |
| |
| |
| class LinuxToolset(UnixToolset): |
| def __init__(self, src_dir): |
| UnixToolset.__init__(self, src_dir) |
| |
| def dl_libraries(self): |
| return ['dl'] |
| |
| |
| def make_toolset(src_dir): |
| platform = sys.platform |
| if platform in {'win32', 'cygwin'}: |
| raise RuntimeError('not implemented on this platform') |
| elif platform == 'darwin': |
| return DarwinToolset(src_dir) |
| elif platform in {'linux', 'linux2'}: |
| return LinuxToolset(src_dir) |
| else: |
| return UnixToolset(src_dir) |
| |
| |
| class Configure(object): |
| def __init__(self, toolset): |
| self.ctx = toolset |
| self.results = {'APPLE': sys.platform == 'darwin'} |
| |
| def _try_to_compile_and_link(self, source): |
| try: |
| with TemporaryDirectory() as work_dir: |
| src_file = 'check.c' |
| with open(os.path.join(work_dir, src_file), 'w') as handle: |
| handle.write(source) |
| |
| execute([self.ctx.compiler, src_file] + self.ctx.c_flags, |
| cwd=work_dir) |
| return True |
| except Exception: |
| return False |
| |
| def check_function_exists(self, function, name): |
| template = "int FUNCTION(); int main() { return FUNCTION(); }" |
| source = template.replace("FUNCTION", function) |
| |
| logging.debug('Checking function %s', function) |
| found = self._try_to_compile_and_link(source) |
| logging.debug('Checking function %s -- %s', function, |
| 'found' if found else 'not found') |
| self.results.update({name: found}) |
| |
| def check_symbol_exists(self, symbol, include, name): |
| template = """#include <INCLUDE> |
| int main() { return ((int*)(&SYMBOL))[0]; }""" |
| source = template.replace('INCLUDE', include).replace("SYMBOL", symbol) |
| |
| logging.debug('Checking symbol %s', symbol) |
| found = self._try_to_compile_and_link(source) |
| logging.debug('Checking symbol %s -- %s', symbol, |
| 'found' if found else 'not found') |
| self.results.update({name: found}) |
| |
| def write_by_template(self, template, output): |
| def transform(line, definitions): |
| |
| pattern = re.compile(r'^#cmakedefine\s+(\S+)') |
| m = pattern.match(line) |
| if m: |
| key = m.group(1) |
| if key not in definitions or not definitions[key]: |
| return '/* #undef {0} */{1}'.format(key, os.linesep) |
| else: |
| return '#define {0}{1}'.format(key, os.linesep) |
| return line |
| |
| with open(template, 'r') as src_handle: |
| logging.debug('Writing config to %s', output) |
| with open(output, 'w') as dst_handle: |
| for line in src_handle: |
| dst_handle.write(transform(line, self.results)) |
| |
| |
| def do_configure(toolset): |
| return Configure(toolset) |
| |
| |
| class SharedLibrary(object): |
| def __init__(self, name, toolset): |
| self.name = toolset.shared_library_name(name) |
| self.ctx = toolset |
| self.inc = [] |
| self.src = [] |
| self.lib = [] |
| |
| def add_include(self, directory): |
| self.inc.extend(['-I', directory]) |
| |
| def add_sources(self, source): |
| self.src.append(source) |
| |
| def link_against(self, libraries): |
| self.lib.extend(['-l' + lib for lib in libraries]) |
| |
| def build_release(self, directory): |
| for src in self.src: |
| logging.debug('Compiling %s', src) |
| execute( |
| [self.ctx.compiler, '-c', os.path.join(self.ctx.src_dir, src), |
| '-o', src + '.o'] + self.inc + |
| self.ctx.shared_library_c_flags(True), |
| cwd=directory) |
| logging.debug('Linking %s', self.name) |
| execute( |
| [self.ctx.compiler] + [src + '.o' for src in self.src] + |
| ['-o', self.name] + self.lib + |
| self.ctx.shared_library_ld_flags(True, self.name), |
| cwd=directory) |
| |
| |
| def create_shared_library(name, toolset): |
| return SharedLibrary(name, toolset) |
