diff options
Diffstat (limited to 'binary_search_tool/bisect_driver.py')
| -rw-r--r-- | binary_search_tool/bisect_driver.py | 120 |
1 files changed, 93 insertions, 27 deletions
diff --git a/binary_search_tool/bisect_driver.py b/binary_search_tool/bisect_driver.py index 0b3fb1d4..21dd11fa 100644 --- a/binary_search_tool/bisect_driver.py +++ b/binary_search_tool/bisect_driver.py @@ -1,8 +1,8 @@ -# Copyright 2016 Google Inc. All Rights Reserved. +# Copyright 2016 Googie Inc. All rights Reserved. # -# This script is used to help the compiler wrapper in the Android build system -# bisect for bad object files. -"""Utilities for bisection of Android object files. +# This script is used to help the compiler wrapper in the ChromeOS and +# Android build systems bisect for bad object files. +"""Utilities for bisection of ChromeOS and Android object files. This module contains a set of utilities to allow bisection between two sets (good and bad) of object files. Mostly used to find compiler @@ -24,7 +24,7 @@ import shutil import subprocess import sys -VALID_MODES = ['POPULATE_GOOD', 'POPULATE_BAD', 'TRIAGE'] +VALID_MODES = ('POPULATE_GOOD', 'POPULATE_BAD', 'TRIAGE') GOOD_CACHE = 'good' BAD_CACHE = 'bad' LIST_FILE = os.path.join(GOOD_CACHE, '_LIST') @@ -35,7 +35,6 @@ WRAPPER_SAFE_MODE = os.environ.get('BISECT_WRAPPER_SAFE_MODE', None) == '1' class Error(Exception): """The general compiler wrapper error class.""" - pass @contextlib.contextmanager @@ -58,7 +57,13 @@ def lock_file(path, mode): mode: mode to open file with ('w', 'r', etc.) """ with open(path, mode) as f: - # Share the lock if just reading, make lock exclusive if writing + # Apply FD_CLOEXEC argument to fd. This ensures that the file descriptor + # won't be leaked to any child processes. + current_args = fcntl.fcntl(f.fileno(), fcntl.F_GETFD) + fcntl.fcntl(f.fileno(), fcntl.F_SETFD, current_args | fcntl.FD_CLOEXEC) + + # Reads can share the lock as no race conditions exist. If write is needed, + # give writing process exclusive access to the file. if f.mode == 'r' or f.mode == 'rb': lock_type = fcntl.LOCK_SH else: @@ -68,8 +73,6 @@ def lock_file(path, mode): fcntl.lockf(f, lock_type) yield f f.flush() - except: - raise finally: fcntl.lockf(f, fcntl.LOCK_UN) @@ -103,8 +106,7 @@ def which_cache(obj_file): determine where an object file should be linked from (good or bad). """ bad_set_file = os.environ.get('BISECT_BAD_SET') - ret = subprocess.call(['grep', '-x', '-q', obj_file, bad_set_file]) - if ret == 0: + if in_object_list(obj_file, bad_set_file): return BAD_CACHE else: return GOOD_CACHE @@ -124,18 +126,29 @@ def get_obj_path(execargs): Returns: Absolute object path from execution args (-o argument). If no object being - outputted or output doesn't end in ".o" then return empty string. + outputted, then return empty string. -o argument is checked only if -c is + also present. """ try: i = execargs.index('-o') + _ = execargs.index('-c') except ValueError: return '' obj_path = execargs[i + 1] - if not obj_path.endswith(('.o',)): - # TODO: what suffixes do we need to contemplate - # TODO: add this as a warning - # TODO: need to handle -r compilations + # Ignore args that do not create a file. + if obj_path in ( + '-', + '/dev/null',): + return '' + # Ignore files ending in .tmp. + if obj_path.endswith(('.tmp',)): + return '' + # Ignore configuration files generated by Automake/Autoconf/CMake etc. + if (obj_path.endswith('conftest.o') or + obj_path.endswith('CMakeFiles/test.o') or + obj_path.find('CMakeTmp') != -1 or + os.path.abspath(obj_path).find('CMakeTmp') != -1): return '' return os.path.abspath(obj_path) @@ -151,7 +164,7 @@ def get_dep_path(execargs): if '-MD' not in execargs and '-MMD' not in execargs: return '' - # If -MF given this is the path of the dependency file. Otherwise the + # If -MF is given this is the path of the dependency file. Otherwise the # dependency file is the value of -o but with a .d extension if '-MF' in execargs: i = execargs.index('-MF') @@ -217,7 +230,16 @@ def get_side_effects(execargs): def cache_file(execargs, bisect_dir, cache, abs_file_path): - """Cache compiler output file (.o/.d/.dwo).""" + """Cache compiler output file (.o/.d/.dwo). + + Args: + execargs: compiler execution arguments. + bisect_dir: The directory where bisection caches live. + cache: Which cache the file will be cached to (GOOD/BAD). + abs_file_path: Absolute path to file being cached. + Returns: + True if caching was successful, False otherwise. + """ # os.path.join fails with absolute paths, use + instead bisect_path = os.path.join(bisect_dir, cache) + abs_file_path bisect_path_dir = os.path.dirname(bisect_path) @@ -227,14 +249,36 @@ def cache_file(execargs, bisect_dir, cache, abs_file_path): try: if os.path.exists(abs_file_path): + if os.path.exists(bisect_path): + # File exists + population_dir = os.path.join(bisect_dir, cache) + with lock_file(os.path.join(population_dir, '_DUPS'), + 'a') as dup_object_list: + dup_object_list.write('%s\n' % abs_file_path) + raise Exception( + 'Trying to cache file %s multiple times.' % abs_file_path) + shutil.copy2(abs_file_path, bisect_path) + # Set cache object to be read-only so later compilations can't + # accidentally overwrite it. + os.chmod(bisect_path, 0o444) + return True + else: + # File not found (happens when compilation fails but error code is still 0) + return False except Exception: print('Could not cache file %s' % abs_file_path, file=sys.stderr) raise def restore_file(bisect_dir, cache, abs_file_path): - """Restore file from cache (.o/.d/.dwo).""" + """Restore file from cache (.o/.d/.dwo). + + Args: + bisect_dir: The directory where bisection caches live. + cache: Which cache the file will be restored from (GOOD/BAD). + abs_file_path: Absolute path to file being restored. + """ # os.path.join fails with absolute paths, use + instead cached_path = os.path.join(bisect_dir, cache) + abs_file_path if os.path.exists(cached_path): @@ -264,21 +308,41 @@ def bisect_populate(execargs, bisect_dir, population_name): return retval full_obj_path = get_obj_path(execargs) - # If not a normal compiler call then just exit + # This is not a normal compiler call because it doesn't have a -o argument, + # or the -o argument has an unusable output file. + # It's likely that this compiler call was actually made to invoke the linker, + # or as part of a configuratoin test. In this case we want to simply call the + # compiler and return. if not full_obj_path: - return + return retval - cache_file(execargs, bisect_dir, population_name, full_obj_path) + # Return if not able to cache the object file + if not cache_file(execargs, bisect_dir, population_name, full_obj_path): + return retval population_dir = os.path.join(bisect_dir, population_name) with lock_file(os.path.join(population_dir, '_LIST'), 'a') as object_list: object_list.write('%s\n' % full_obj_path) for side_effect in get_side_effects(execargs): - cache_file(execargs, bisect_dir, population_name, side_effect) + _ = cache_file(execargs, bisect_dir, population_name, side_effect) + + return retval def bisect_triage(execargs, bisect_dir): + """Use object object file from appropriate cache (good/bad). + + Given a populated bisection directory, use the object file saved + into one of the caches (good/bad) according to what is specified + in the good/bad sets. The good/bad sets are generated by the + high level binary search tool. Additionally restore any possible + side effects of compiler. + + Args: + execargs: compiler execution arguments. + bisect_dir: populated bisection directory. + """ full_obj_path = get_obj_path(execargs) obj_list = os.path.join(bisect_dir, LIST_FILE) @@ -309,7 +373,7 @@ def bisect_triage(execargs, bisect_dir): return retval os.remove(full_obj_path) restore_file(bisect_dir, cache, full_obj_path) - return + return retval # Generate compiler side effects. Trick Make into thinking compiler was # actually executed. @@ -321,14 +385,16 @@ def bisect_triage(execargs, bisect_dir): if not os.path.exists(full_obj_path): restore_file(bisect_dir, cache, full_obj_path) + return 0 + def bisect_driver(bisect_stage, bisect_dir, execargs): """Call appropriate bisection stage according to value in bisect_stage.""" if bisect_stage == 'POPULATE_GOOD': - bisect_populate(execargs, bisect_dir, GOOD_CACHE) + return bisect_populate(execargs, bisect_dir, GOOD_CACHE) elif bisect_stage == 'POPULATE_BAD': - bisect_populate(execargs, bisect_dir, BAD_CACHE) + return bisect_populate(execargs, bisect_dir, BAD_CACHE) elif bisect_stage == 'TRIAGE': - bisect_triage(execargs, bisect_dir) + return bisect_triage(execargs, bisect_dir) else: raise ValueError('wrong value for BISECT_STAGE: %s' % bisect_stage) |