Improving CVISE for large projects

cvise.py

@@ -85,29 +85,6 @@ def get_available_pass_groups():
     return group_names
 
 
-def get_available_cores():
-    try:
-        # try to detect only physical cores, ignore HyperThreading
-        # in order to speed up parallel execution
-        core_count = psutil.cpu_count(logical=False)
-        if not core_count:
-            core_count = psutil.cpu_count(logical=True)
-        # respect affinity
-        try:
-            affinity = len(psutil.Process().cpu_affinity())
-            assert affinity >= 1
-        except AttributeError:
-            return core_count
-
-        if core_count:
-            core_count = min(core_count, affinity)
-        else:
-            core_count = affinity
-        return core_count
-    except NotImplementedError:
-        return 1
-
-
 EPILOG_TEXT = f"""
 available shortcuts:
   S - skip execution of the current pass
@@ -118,6 +95,7 @@ def get_available_cores():
 """
 
 if __name__ == '__main__':
+    default_timeout_value = 300
     parser = argparse.ArgumentParser(
         description='C-Vise',
         formatter_class=argparse.RawDescriptionHelpFormatter,
@@ -127,8 +105,8 @@ def get_available_cores():
         '--n',
         '-n',
         type=int,
-        default=get_available_cores(),
-        help='Number of cores to use; C-Vise tries to automatically pick a good setting but its choice may be too low or high for your situation',
+        default=-1,
+        help=f'Number of cores to use; C-Vise tries to automatically pick a good setting but its choice may be too low or high for your situation. Usually defaults to {testing.TestManager.get_available_cores()}. May be less on large TEST_CASEs.',
     )
     parser.add_argument(
         '--tidy',
@@ -161,6 +139,12 @@ def get_available_cores():
         action='store_true',
         help='Print debug information (alias for --log-level=DEBUG)',
     )
+    parser.add_argument(
+        '-w',
+        action='store_false',
+        default=True,
+        help='Do not double-check command-line arguments.',
+    )
     parser.add_argument(
         '--log-level',
         type=str,
@@ -218,8 +202,8 @@ def get_available_cores():
         '--timeout',
         type=int,
         nargs='?',
-        default=300,
-        help='Interestingness test timeout in seconds',
+        default=-1,
+        help=f'Interestingness test timeout in seconds. Defaults to {default_timeout_value}.',
     )
     parser.add_argument('--no-cache', action='store_true', help="Don't cache behavior of passes")
     parser.add_argument(
@@ -233,12 +217,18 @@ def get_available_cores():
         type=int,
         help='Largest improvement in file size from a single transformation that C-Vise should accept (useful only to slow C-Vise down)',
     )
+    parser.add_argument(
+        '--min-improvement',
+        metavar='BYTES',
+        type=int,
+        help='Minimum improvement in file size from a single transformation that C-Vise should accept',
+    )
     passes_group = parser.add_mutually_exclusive_group()
     passes_group.add_argument(
         '--pass-group',
         type=str,
         choices=get_available_pass_groups(),
-        help='Set of passes used during the reduction',
+        help='Set of passes used during the reduction.',
     )
     passes_group.add_argument('--pass-group-file', type=str, help='JSON file defining a custom pass group')
     parser.add_argument(
@@ -262,7 +252,7 @@ def get_available_cores():
         action='store_true',
         help='Enable all renaming passes (that are disabled by default)',
     )
-    parser.add_argument('--list-passes', action='store_true', help='Print all available passes and exit')
+    parser.add_argument('--list-passes', action='store_true', help='Print all available passes and exit. Works with --not-c (showing available passes not specific to C and C++), --renaming (showing available renaming passes), and --sllooww (showing availalbe passes, activated with the --sllooww option).')
     parser.add_argument(
         '--version',
         action='version',
@@ -274,7 +264,7 @@ def get_available_cores():
         '-c',
         help='Use shell commands instead of an interestingness test case',
     )
-    parser.add_argument('--shell', default='bash', help='Use selected shell for the --commands option')
+    parser.add_argument('--shell', default='bash', help='Use selected shell for the --commands option. Defaults to "bash"')
     parser.add_argument(
         '--to-utf8',
         action='store_true',
@@ -296,10 +286,17 @@ def get_available_cores():
         '--stopping-threshold',
         default=1.0,
         type=float,
-        help='CVise will stop reducing a test case once it has reduced by this fraction of its original size.  Between 0.0 and 1.0.',
+        help='CVise will stop reducing a test case once it has reduced by this fraction of its original size.  Between 0.0 and 1.0. Defaults to 1.0',
     )
 
-    args = parser.parse_args()
+    # TEST_CASE may not be required, when `--list-passes` is provided. But the parser doesn't know.
+    # Thus, we insert a dummy element so that the parser won't complain.
+    if '--list-passes' in sys.argv:
+        cmd_args = sys.argv[1:]
+        cmd_args.append("/dev/null")
+        args = parser.parse_args(cmd_args)
+    else:
+        args = parser.parse_args()
 
     log_config = {}
 
@@ -358,13 +355,21 @@ def get_available_cores():
     )
     if args.list_passes:
         logging.info('Available passes:')
+        logging.info('==============')
         logging.info('INITIAL PASSES')
+        logging.info('==============')
         for p in pass_group['first']:
             logging.info(str(p))
+        logging.info('')
+        logging.info('==============')
         logging.info('MAIN PASSES')
+        logging.info('==============')
         for p in pass_group['main']:
             logging.info(str(p))
+        logging.info('')
+        logging.info('==============')
         logging.info('CLEANUP PASSES')
+        logging.info('==============')
         for p in pass_group['last']:
             logging.info(str(p))
         sys.exit(0)
@@ -408,6 +413,9 @@ def get_available_cores():
         logging.info(f'Using temporary interestingness test: {script.name}')
         args.interestingness_test = script.name
 
+    if args.timeout <= 0:
+        args.timeout = default_timeout_value
+
     test_manager = testing.TestManager(
         pass_statistic,
         args.interestingness_test,
@@ -421,11 +429,13 @@ def get_available_cores():
         args.die_on_pass_bug,
         args.print_diff,
         args.max_improvement,
+        args.min_improvement,
         args.no_give_up,
         args.also_interesting,
         args.start_with_pass,
         args.skip_after_n_transforms,
         args.stopping_threshold,
+        args.w,
     )
 
     reducer = CVise(test_manager, args.skip_interestingness_test_check)

cvise/cvise.py

@@ -5,6 +5,7 @@
 from cvise.passes.abstract import AbstractPass
 from cvise.passes.balanced import BalancedPass
 from cvise.passes.blank import BlankPass
+from cvise.passes.clear import ClearPass
 from cvise.passes.clang import ClangPass
 from cvise.passes.clangbinarysearch import ClangBinarySearchPass
 from cvise.passes.clex import ClexPass
@@ -41,6 +42,7 @@ class Info:
         'blank': BlankPass,
         'clang': ClangPass,
         'clangbinarysearch': ClangBinarySearchPass,
+        'clear': ClearPass,
         'clex': ClexPass,
         'comments': CommentsPass,
         'gcda-binary': GCDABinaryPass,

cvise/passes/clangbinarysearch.py

@@ -11,6 +11,8 @@
 
 class ClangBinarySearchPass(AbstractPass):
     QUERY_TIMEOUT = 10
+    QUERY_MAX_TIMEOUTS = 30
+    QUERY_CUR_TIMEOUT = 0
 
     def check_prerequisites(self):
         return self.check_external_program('clang_delta')
@@ -51,6 +53,8 @@ def advance_on_success(self, test_case, state):
         return state
 
     def count_instances(self, test_case):
+        if self.QUERY_CUR_TIMEOUT >= self.QUERY_MAX_TIMEOUTS:
+            return 0
         assert self.clang_delta_std
         args = [
             self.external_programs['clang_delta'],
@@ -64,8 +68,9 @@ def count_instances(self, test_case):
         try:
             proc = subprocess.run(cmd, text=True, capture_output=True, timeout=self.QUERY_TIMEOUT)
         except subprocess.TimeoutExpired:
+            self.QUERY_CUR_TIMEOUT += 1
             logging.warning(
-                f'clang_delta --query-instances (--std={self.clang_delta_std}) {self.QUERY_TIMEOUT}s timeout reached'
+                f'[{self.QUERY_CUR_TIMEOUT:{len(str(self.QUERY_MAX_TIMEOUTS))}}/{self.QUERY_MAX_TIMEOUTS:{len(str(self.QUERY_MAX_TIMEOUTS))}}] clang_delta --query-instances (--std={self.clang_delta_std}) {self.QUERY_TIMEOUT}s timeout reached. Cmd: {cmd}'
             )
             return 0
         except subprocess.SubprocessError as e:

cvise/passes/clear.py

@@ -0,0 +1,31 @@
+import os
+import shutil
+import tempfile
+
+from cvise.passes.abstract import AbstractPass, PassResult
+
+
+class ClearPass(AbstractPass):
+    def check_prerequisites(self):
+        return True
+
+    def new(self, test_case, _=None):
+        return 0
+
+    def advance(self, test_case, state):
+        return state + 1
+
+    def advance_on_success(self, test_case, state):
+        return state
+
+    @staticmethod
+    def __transform(test_case):
+        if os.path.getsize(test_case) == 0:
+            return False
+        tmp = os.path.dirname(test_case)
+        tmp_file = tempfile.NamedTemporaryFile(mode='w+', delete=False, dir=tmp)
+        shutil.move(tmp_file.name, test_case)
+        return True
+
+    def transform(self, test_case, state, process_event_notifier):
+        return (PassResult.OK if self.__transform(test_case) else PassResult.STOP, state)

cvise/utils/error.py

@@ -90,6 +90,11 @@ def __str__(self):
         return 'Could not find a directory with definitions for pass groups!'
 
 
+class KeyboardInterruption(CViseError):
+    def __str__(self):
+        return 'Got Ctrl+C'
+
+
 class PassBugError(CViseError):
     MSG = """***************************************************
 

cvise/utils/statistics.py

@@ -8,6 +8,7 @@ def __init__(self, pass_name):
         self.worked = 0
         self.failed = 0
         self.totally_executed = 0
+        self.improvement = 0
 
 
 class PassStatistic:
@@ -39,6 +40,10 @@ def add_success(self, pass_):
         pass_name = repr(pass_)
         self.stats[pass_name].worked += 1
 
+    def add_improvement(self, pass_, bytes_):
+        pass_name = repr(pass_)
+        self.stats[pass_name].improvement += bytes_
+
     def add_failure(self, pass_):
         pass_name = repr(pass_)
         self.stats[pass_name].failed += 1