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Diffstat (limited to 'extras/stracedeps.py')
| -rw-r--r-- | extras/stracedeps.py | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/extras/stracedeps.py b/extras/stracedeps.py new file mode 100644 index 0000000..37d82cb --- /dev/null +++ b/extras/stracedeps.py @@ -0,0 +1,174 @@ +#!/usr/bin/env python +# encoding: utf-8 +# Thomas Nagy, 2015 (ita) + +""" +Execute tasks through strace to obtain dependencies after the process is run. This +scheme is similar to that of the Fabricate script. + +To use:: + + def configure(conf): + conf.load('strace') + +WARNING: +* This will not work when advanced scanners are needed (qt4/qt5) +* The overhead of running 'strace' is significant (56s -> 1m29s) +* It will not work on Windows :-) +""" + +import os, re, threading +from waflib import Task, Logs, Utils + +#TRACECALLS = 'trace=access,chdir,clone,creat,execve,exit_group,fork,lstat,lstat64,mkdir,open,rename,stat,stat64,symlink,vfork' +TRACECALLS = 'trace=process,file' + +BANNED = ('/tmp', '/proc', '/sys', '/dev') + +s_process = r'(?:clone|fork|vfork)\(.*?(?P<npid>\d+)' +s_file = r'(?P<call>\w+)\("(?P<path>([^"\\]|\\.)*)"(.*)' +re_lines = re.compile(r'^(?P<pid>\d+)\s+(?:(?:%s)|(?:%s))\r*$' % (s_file, s_process), re.IGNORECASE | re.MULTILINE) +strace_lock = threading.Lock() + +def configure(conf): + conf.find_program('strace') + +def task_method(func): + # Decorator function to bind/replace methods on the base Task class + # + # The methods Task.exec_command and Task.sig_implicit_deps already exists and are rarely overridden + # we thus expect that we are the only ones doing this + try: + setattr(Task.Task, 'nostrace_%s' % func.__name__, getattr(Task.Task, func.__name__)) + except AttributeError: + pass + setattr(Task.Task, func.__name__, func) + return func + +@task_method +def get_strace_file(self): + try: + return self.strace_file + except AttributeError: + pass + + if self.outputs: + ret = self.outputs[0].abspath() + '.strace' + else: + ret = '%s%s%d%s' % (self.generator.bld.bldnode.abspath(), os.sep, id(self), '.strace') + self.strace_file = ret + return ret + +@task_method +def get_strace_args(self): + return (self.env.STRACE or ['strace']) + ['-e', TRACECALLS, '-f', '-o', self.get_strace_file()] + +@task_method +def exec_command(self, cmd, **kw): + bld = self.generator.bld + if not 'cwd' in kw: + kw['cwd'] = self.get_cwd() + + args = self.get_strace_args() + fname = self.get_strace_file() + if isinstance(cmd, list): + cmd = args + cmd + else: + cmd = '%s %s' % (' '.join(args), cmd) + + try: + ret = bld.exec_command(cmd, **kw) + finally: + if not ret: + self.parse_strace_deps(fname, kw['cwd']) + return ret + +@task_method +def sig_implicit_deps(self): + # bypass the scanner functions + return + +@task_method +def parse_strace_deps(self, path, cwd): + # uncomment the following line to disable the dependencies and force a file scan + # return + try: + cnt = Utils.readf(path) + finally: + try: + os.remove(path) + except OSError: + pass + + if not isinstance(cwd, str): + cwd = cwd.abspath() + + nodes = [] + bld = self.generator.bld + try: + cache = bld.strace_cache + except AttributeError: + cache = bld.strace_cache = {} + + # chdir and relative paths + pid_to_cwd = {} + + global BANNED + done = set() + for m in re.finditer(re_lines, cnt): + # scraping the output of strace + pid = m.group('pid') + if m.group('npid'): + npid = m.group('npid') + pid_to_cwd[npid] = pid_to_cwd.get(pid, cwd) + continue + + p = m.group('path').replace('\\"', '"') + + if p == '.' or m.group().find('= -1 ENOENT') > -1: + # just to speed it up a bit + continue + + if not os.path.isabs(p): + p = os.path.join(pid_to_cwd.get(pid, cwd), p) + + call = m.group('call') + if call == 'chdir': + pid_to_cwd[pid] = p + continue + + if p in done: + continue + done.add(p) + + for x in BANNED: + if p.startswith(x): + break + else: + if p.endswith('/') or os.path.isdir(p): + continue + + try: + node = cache[p] + except KeyError: + strace_lock.acquire() + try: + cache[p] = node = bld.root.find_node(p) + if not node: + continue + finally: + strace_lock.release() + nodes.append(node) + + # record the dependencies then force the task signature recalculation for next time + if Logs.verbose: + Logs.debug('deps: real scanner for %r returned %r', self, nodes) + bld = self.generator.bld + bld.node_deps[self.uid()] = nodes + bld.raw_deps[self.uid()] = [] + try: + del self.cache_sig + except AttributeError: + pass + self.signature() + |