Mercurial > hg
view contrib/import-checker.py @ 44712:a825bfbf6642
templatekw: cache mergestate even if merge is not ongoing
While playing with eBPF, I noticed .hg/merge/state{,2} files were tried
to open() for each revision. That's not healthy. Let's cache the "inactive"
state as well.
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Wed, 15 Apr 2020 23:11:55 +0900 |
parents | 4cabeea6d214 |
children | c102b704edb5 |
line wrap: on
line source
#!/usr/bin/env python from __future__ import absolute_import, print_function import ast import collections import io import os import sys # Import a minimal set of stdlib modules needed for list_stdlib_modules() # to work when run from a virtualenv. The modules were chosen empirically # so that the return value matches the return value without virtualenv. if True: # disable lexical sorting checks try: import BaseHTTPServer as basehttpserver except ImportError: basehttpserver = None import zlib import testparseutil # Whitelist of modules that symbols can be directly imported from. allowsymbolimports = ( '__future__', 'bzrlib', 'hgclient', 'mercurial', 'mercurial.hgweb.common', 'mercurial.hgweb.request', 'mercurial.i18n', 'mercurial.interfaces', 'mercurial.node', 'mercurial.pycompat', # for revlog to re-export constant to extensions 'mercurial.revlogutils.constants', 'mercurial.revlogutils.flagutil', # for cffi modules to re-export pure functions 'mercurial.pure.base85', 'mercurial.pure.bdiff', 'mercurial.pure.mpatch', 'mercurial.pure.osutil', 'mercurial.pure.parsers', # third-party imports should be directly imported 'mercurial.thirdparty', 'mercurial.thirdparty.attr', 'mercurial.thirdparty.zope', 'mercurial.thirdparty.zope.interface', ) # Whitelist of symbols that can be directly imported. directsymbols = ('demandimport',) # Modules that must be aliased because they are commonly confused with # common variables and can create aliasing and readability issues. requirealias = { 'ui': 'uimod', } def usingabsolute(root): """Whether absolute imports are being used.""" if sys.version_info[0] >= 3: return True for node in ast.walk(root): if isinstance(node, ast.ImportFrom): if node.module == '__future__': for n in node.names: if n.name == 'absolute_import': return True return False def walklocal(root): """Recursively yield all descendant nodes but not in a different scope""" todo = collections.deque(ast.iter_child_nodes(root)) yield root, False while todo: node = todo.popleft() newscope = isinstance(node, ast.FunctionDef) if not newscope: todo.extend(ast.iter_child_nodes(node)) yield node, newscope def dotted_name_of_path(path): """Given a relative path to a source file, return its dotted module name. >>> dotted_name_of_path('mercurial/error.py') 'mercurial.error' >>> dotted_name_of_path('zlibmodule.so') 'zlib' """ parts = path.replace(os.sep, '/').split('/') parts[-1] = parts[-1].split('.', 1)[0] # remove .py and .so and .ARCH.so if parts[-1].endswith('module'): parts[-1] = parts[-1][:-6] return '.'.join(parts) def fromlocalfunc(modulename, localmods): """Get a function to examine which locally defined module the target source imports via a specified name. `modulename` is an `dotted_name_of_path()`-ed source file path, which may have `.__init__` at the end of it, of the target source. `localmods` is a set of absolute `dotted_name_of_path()`-ed source file paths of locally defined (= Mercurial specific) modules. This function assumes that module names not existing in `localmods` are from the Python standard library. This function returns the function, which takes `name` argument, and returns `(absname, dottedpath, hassubmod)` tuple if `name` matches against locally defined module. Otherwise, it returns False. It is assumed that `name` doesn't have `.__init__`. `absname` is an absolute module name of specified `name` (e.g. "hgext.convert"). This can be used to compose prefix for sub modules or so. `dottedpath` is a `dotted_name_of_path()`-ed source file path (e.g. "hgext.convert.__init__") of `name`. This is used to look module up in `localmods` again. `hassubmod` is whether it may have sub modules under it (for convenient, even though this is also equivalent to "absname != dottednpath") >>> localmods = {'foo.__init__', 'foo.foo1', ... 'foo.bar.__init__', 'foo.bar.bar1', ... 'baz.__init__', 'baz.baz1'} >>> fromlocal = fromlocalfunc('foo.xxx', localmods) >>> # relative >>> fromlocal('foo1') ('foo.foo1', 'foo.foo1', False) >>> fromlocal('bar') ('foo.bar', 'foo.bar.__init__', True) >>> fromlocal('bar.bar1') ('foo.bar.bar1', 'foo.bar.bar1', False) >>> # absolute >>> fromlocal('baz') ('baz', 'baz.__init__', True) >>> fromlocal('baz.baz1') ('baz.baz1', 'baz.baz1', False) >>> # unknown = maybe standard library >>> fromlocal('os') False >>> fromlocal(None, 1) ('foo', 'foo.__init__', True) >>> fromlocal('foo1', 1) ('foo.foo1', 'foo.foo1', False) >>> fromlocal2 = fromlocalfunc('foo.xxx.yyy', localmods) >>> fromlocal2(None, 2) ('foo', 'foo.__init__', True) >>> fromlocal2('bar2', 1) False >>> fromlocal2('bar', 2) ('foo.bar', 'foo.bar.__init__', True) """ if not isinstance(modulename, str): modulename = modulename.decode('ascii') prefix = '.'.join(modulename.split('.')[:-1]) if prefix: prefix += '.' def fromlocal(name, level=0): # name is false value when relative imports are used. if not name: # If relative imports are used, level must not be absolute. assert level > 0 candidates = ['.'.join(modulename.split('.')[:-level])] else: if not level: # Check relative name first. candidates = [prefix + name, name] else: candidates = [ '.'.join(modulename.split('.')[:-level]) + '.' + name ] for n in candidates: if n in localmods: return (n, n, False) dottedpath = n + '.__init__' if dottedpath in localmods: return (n, dottedpath, True) return False return fromlocal def populateextmods(localmods): """Populate C extension modules based on pure modules""" newlocalmods = set(localmods) for n in localmods: if n.startswith('mercurial.pure.'): m = n[len('mercurial.pure.') :] newlocalmods.add('mercurial.cext.' + m) newlocalmods.add('mercurial.cffi._' + m) return newlocalmods def list_stdlib_modules(): """List the modules present in the stdlib. >>> py3 = sys.version_info[0] >= 3 >>> mods = set(list_stdlib_modules()) >>> 'BaseHTTPServer' in mods or py3 True os.path isn't really a module, so it's missing: >>> 'os.path' in mods False sys requires special treatment, because it's baked into the interpreter, but it should still appear: >>> 'sys' in mods True >>> 'collections' in mods True >>> 'cStringIO' in mods or py3 True >>> 'cffi' in mods True """ for m in sys.builtin_module_names: yield m # These modules only exist on windows, but we should always # consider them stdlib. for m in ['msvcrt', '_winreg']: yield m yield '__builtin__' yield 'builtins' # python3 only yield 'importlib.abc' # python3 only yield 'importlib.machinery' # python3 only yield 'importlib.util' # python3 only for m in 'fcntl', 'grp', 'pwd', 'termios': # Unix only yield m for m in 'cPickle', 'datetime': # in Python (not C) on PyPy yield m for m in ['cffi']: yield m stdlib_prefixes = {sys.prefix, sys.exec_prefix} # We need to supplement the list of prefixes for the search to work # when run from within a virtualenv. for mod in (basehttpserver, zlib): if mod is None: continue try: # Not all module objects have a __file__ attribute. filename = mod.__file__ except AttributeError: continue dirname = os.path.dirname(filename) for prefix in stdlib_prefixes: if dirname.startswith(prefix): # Then this directory is redundant. break else: stdlib_prefixes.add(dirname) sourceroot = os.path.abspath(os.path.dirname(os.path.dirname(__file__))) for libpath in sys.path: # We want to walk everything in sys.path that starts with something in # stdlib_prefixes, but not directories from the hg sources. if os.path.abspath(libpath).startswith(sourceroot) or not any( libpath.startswith(p) for p in stdlib_prefixes ): continue for top, dirs, files in os.walk(libpath): for i, d in reversed(list(enumerate(dirs))): if ( not os.path.exists(os.path.join(top, d, '__init__.py')) or top == libpath and d in ('hgdemandimport', 'hgext', 'mercurial') ): del dirs[i] for name in files: if not name.endswith(('.py', '.so', '.pyc', '.pyo', '.pyd')): continue if name.startswith('__init__.py'): full_path = top else: full_path = os.path.join(top, name) rel_path = full_path[len(libpath) + 1 :] mod = dotted_name_of_path(rel_path) yield mod stdlib_modules = set(list_stdlib_modules()) def imported_modules(source, modulename, f, localmods, ignore_nested=False): """Given the source of a file as a string, yield the names imported by that file. Args: source: The python source to examine as a string. modulename: of specified python source (may have `__init__`) localmods: set of locally defined module names (may have `__init__`) ignore_nested: If true, import statements that do not start in column zero will be ignored. Returns: A list of absolute module names imported by the given source. >>> f = 'foo/xxx.py' >>> modulename = 'foo.xxx' >>> localmods = {'foo.__init__': True, ... 'foo.foo1': True, 'foo.foo2': True, ... 'foo.bar.__init__': True, 'foo.bar.bar1': True, ... 'baz.__init__': True, 'baz.baz1': True } >>> # standard library (= not locally defined ones) >>> sorted(imported_modules( ... 'from stdlib1 import foo, bar; import stdlib2', ... modulename, f, localmods)) [] >>> # relative importing >>> sorted(imported_modules( ... 'import foo1; from bar import bar1', ... modulename, f, localmods)) ['foo.bar.bar1', 'foo.foo1'] >>> sorted(imported_modules( ... 'from bar.bar1 import name1, name2, name3', ... modulename, f, localmods)) ['foo.bar.bar1'] >>> # absolute importing >>> sorted(imported_modules( ... 'from baz import baz1, name1', ... modulename, f, localmods)) ['baz.__init__', 'baz.baz1'] >>> # mixed importing, even though it shouldn't be recommended >>> sorted(imported_modules( ... 'import stdlib, foo1, baz', ... modulename, f, localmods)) ['baz.__init__', 'foo.foo1'] >>> # ignore_nested >>> sorted(imported_modules( ... '''import foo ... def wat(): ... import bar ... ''', modulename, f, localmods)) ['foo.__init__', 'foo.bar.__init__'] >>> sorted(imported_modules( ... '''import foo ... def wat(): ... import bar ... ''', modulename, f, localmods, ignore_nested=True)) ['foo.__init__'] """ fromlocal = fromlocalfunc(modulename, localmods) for node in ast.walk(ast.parse(source, f)): if ignore_nested and getattr(node, 'col_offset', 0) > 0: continue if isinstance(node, ast.Import): for n in node.names: found = fromlocal(n.name) if not found: # this should import standard library continue yield found[1] elif isinstance(node, ast.ImportFrom): found = fromlocal(node.module, node.level) if not found: # this should import standard library continue absname, dottedpath, hassubmod = found if not hassubmod: # "dottedpath" is not a package; must be imported yield dottedpath # examination of "node.names" should be redundant # e.g.: from mercurial.node import nullid, nullrev continue modnotfound = False prefix = absname + '.' for n in node.names: found = fromlocal(prefix + n.name) if not found: # this should be a function or a property of "node.module" modnotfound = True continue yield found[1] if modnotfound and dottedpath != modulename: # "dottedpath" is a package, but imported because of non-module # lookup # specifically allow "from . import foo" from __init__.py yield dottedpath def verify_import_convention(module, source, localmods): """Verify imports match our established coding convention. We have 2 conventions: legacy and modern. The modern convention is in effect when using absolute imports. The legacy convention only looks for mixed imports. The modern convention is much more thorough. """ root = ast.parse(source) absolute = usingabsolute(root) if absolute: return verify_modern_convention(module, root, localmods) else: return verify_stdlib_on_own_line(root) def verify_modern_convention(module, root, localmods, root_col_offset=0): """Verify a file conforms to the modern import convention rules. The rules of the modern convention are: * Ordering is stdlib followed by local imports. Each group is lexically sorted. * Importing multiple modules via "import X, Y" is not allowed: use separate import statements. * Importing multiple modules via "from X import ..." is allowed if using parenthesis and one entry per line. * Only 1 relative import statement per import level ("from .", "from ..") is allowed. * Relative imports from higher levels must occur before lower levels. e.g. "from .." must be before "from .". * Imports from peer packages should use relative import (e.g. do not "import mercurial.foo" from a "mercurial.*" module). * Symbols can only be imported from specific modules (see `allowsymbolimports`). For other modules, first import the module then assign the symbol to a module-level variable. In addition, these imports must be performed before other local imports. This rule only applies to import statements outside of any blocks. * Relative imports from the standard library are not allowed, unless that library is also a local module. * Certain modules must be aliased to alternate names to avoid aliasing and readability problems. See `requirealias`. """ if not isinstance(module, str): module = module.decode('ascii') topmodule = module.split('.')[0] fromlocal = fromlocalfunc(module, localmods) # Whether a local/non-stdlib import has been performed. seenlocal = None # Whether a local/non-stdlib, non-symbol import has been seen. seennonsymbollocal = False # The last name to be imported (for sorting). lastname = None laststdlib = None # Relative import levels encountered so far. seenlevels = set() for node, newscope in walklocal(root): def msg(fmt, *args): return (fmt % args, node.lineno) if newscope: # Check for local imports in function for r in verify_modern_convention( module, node, localmods, node.col_offset + 4 ): yield r elif isinstance(node, ast.Import): # Disallow "import foo, bar" and require separate imports # for each module. if len(node.names) > 1: yield msg( 'multiple imported names: %s', ', '.join(n.name for n in node.names), ) name = node.names[0].name asname = node.names[0].asname stdlib = name in stdlib_modules # Ignore sorting rules on imports inside blocks. if node.col_offset == root_col_offset: if lastname and name < lastname and laststdlib == stdlib: yield msg( 'imports not lexically sorted: %s < %s', name, lastname ) lastname = name laststdlib = stdlib # stdlib imports should be before local imports. if stdlib and seenlocal and node.col_offset == root_col_offset: yield msg( 'stdlib import "%s" follows local import: %s', name, seenlocal, ) if not stdlib: seenlocal = name # Import of sibling modules should use relative imports. topname = name.split('.')[0] if topname == topmodule: yield msg('import should be relative: %s', name) if name in requirealias and asname != requirealias[name]: yield msg( '%s module must be "as" aliased to %s', name, requirealias[name], ) elif isinstance(node, ast.ImportFrom): # Resolve the full imported module name. if node.level > 0: fullname = '.'.join(module.split('.')[: -node.level]) if node.module: fullname += '.%s' % node.module else: assert node.module fullname = node.module topname = fullname.split('.')[0] if topname == topmodule: yield msg('import should be relative: %s', fullname) # __future__ is special since it needs to come first and use # symbol import. if fullname != '__future__': if not fullname or ( fullname in stdlib_modules # allow standard 'from typing import ...' style and fullname.startswith('.') and fullname not in localmods and fullname + '.__init__' not in localmods ): yield msg('relative import of stdlib module') else: seenlocal = fullname # Direct symbol import is only allowed from certain modules and # must occur before non-symbol imports. found = fromlocal(node.module, node.level) if found and found[2]: # node.module is a package prefix = found[0] + '.' symbols = ( n.name for n in node.names if not fromlocal(prefix + n.name) ) else: symbols = (n.name for n in node.names) symbols = [sym for sym in symbols if sym not in directsymbols] if node.module and node.col_offset == root_col_offset: if symbols and fullname not in allowsymbolimports: yield msg( 'direct symbol import %s from %s', ', '.join(symbols), fullname, ) if symbols and seennonsymbollocal: yield msg( 'symbol import follows non-symbol import: %s', fullname ) if not symbols and fullname not in stdlib_modules: seennonsymbollocal = True if not node.module: assert node.level # Only allow 1 group per level. if ( node.level in seenlevels and node.col_offset == root_col_offset ): yield msg( 'multiple "from %s import" statements', '.' * node.level ) # Higher-level groups come before lower-level groups. if any(node.level > l for l in seenlevels): yield msg( 'higher-level import should come first: %s', fullname ) seenlevels.add(node.level) # Entries in "from .X import ( ... )" lists must be lexically # sorted. lastentryname = None for n in node.names: if lastentryname and n.name < lastentryname: yield msg( 'imports from %s not lexically sorted: %s < %s', fullname, n.name, lastentryname, ) lastentryname = n.name if n.name in requirealias and n.asname != requirealias[n.name]: yield msg( '%s from %s must be "as" aliased to %s', n.name, fullname, requirealias[n.name], ) def verify_stdlib_on_own_line(root): """Given some python source, verify that stdlib imports are done in separate statements from relative local module imports. >>> list(verify_stdlib_on_own_line(ast.parse('import sys, foo'))) [('mixed imports\\n stdlib: sys\\n relative: foo', 1)] >>> list(verify_stdlib_on_own_line(ast.parse('import sys, os'))) [] >>> list(verify_stdlib_on_own_line(ast.parse('import foo, bar'))) [] """ for node in ast.walk(root): if isinstance(node, ast.Import): from_stdlib = {False: [], True: []} for n in node.names: from_stdlib[n.name in stdlib_modules].append(n.name) if from_stdlib[True] and from_stdlib[False]: yield ( 'mixed imports\n stdlib: %s\n relative: %s' % ( ', '.join(sorted(from_stdlib[True])), ', '.join(sorted(from_stdlib[False])), ), node.lineno, ) class CircularImport(Exception): pass def checkmod(mod, imports): shortest = {} visit = [[mod]] while visit: path = visit.pop(0) for i in sorted(imports.get(path[-1], [])): if len(path) < shortest.get(i, 1000): shortest[i] = len(path) if i in path: if i == path[0]: raise CircularImport(path) continue visit.append(path + [i]) def rotatecycle(cycle): """arrange a cycle so that the lexicographically first module listed first >>> rotatecycle(['foo', 'bar']) ['bar', 'foo', 'bar'] """ lowest = min(cycle) idx = cycle.index(lowest) return cycle[idx:] + cycle[:idx] + [lowest] def find_cycles(imports): """Find cycles in an already-loaded import graph. All module names recorded in `imports` should be absolute one. >>> from __future__ import print_function >>> imports = {'top.foo': ['top.bar', 'os.path', 'top.qux'], ... 'top.bar': ['top.baz', 'sys'], ... 'top.baz': ['top.foo'], ... 'top.qux': ['top.foo']} >>> print('\\n'.join(sorted(find_cycles(imports)))) top.bar -> top.baz -> top.foo -> top.bar top.foo -> top.qux -> top.foo """ cycles = set() for mod in sorted(imports.keys()): try: checkmod(mod, imports) except CircularImport as e: cycle = e.args[0] cycles.add(" -> ".join(rotatecycle(cycle))) return cycles def _cycle_sortkey(c): return len(c), c def embedded(f, modname, src): """Extract embedded python code >>> def _forcestr(thing): ... if not isinstance(thing, str): ... return thing.decode('ascii') ... return thing >>> def test(fn, lines): ... for s, m, f, l in embedded(fn, b"example", lines): ... print("%s %s %d" % (_forcestr(m), _forcestr(f), l)) ... print(repr(_forcestr(s))) >>> lines = [ ... 'comment', ... ' >>> from __future__ import print_function', ... " >>> ' multiline", ... " ... string'", ... ' ', ... 'comment', ... ' $ cat > foo.py <<EOF', ... ' > from __future__ import print_function', ... ' > EOF', ... ] >>> test(b"example.t", lines) example[2] doctest.py 1 "from __future__ import print_function\\n' multiline\\nstring'\\n\\n" example[8] foo.py 7 'from __future__ import print_function\\n' """ errors = [] for name, starts, ends, code in testparseutil.pyembedded(f, src, errors): if not name: # use 'doctest.py', in order to make already existing # doctest above pass instantly name = 'doctest.py' # "starts" is "line number" (1-origin), but embedded() is # expected to return "line offset" (0-origin). Therefore, this # yields "starts - 1". if not isinstance(modname, str): modname = modname.decode('utf8') yield code, "%s[%d]" % (modname, starts), name, starts - 1 def sources(f, modname): """Yields possibly multiple sources from a filepath input: filepath, modulename yields: script(string), modulename, filepath, linenumber For embedded scripts, the modulename and filepath will be different from the function arguments. linenumber is an offset relative to the input file. """ py = False if not f.endswith('.t'): with open(f, 'rb') as src: yield src.read(), modname, f, 0 py = True if py or f.endswith('.t'): # Strictly speaking we should sniff for the magic header that denotes # Python source file encoding. But in reality we don't use anything # other than ASCII (mainly) and UTF-8 (in a few exceptions), so # simplicity is fine. with io.open(f, 'r', encoding='utf-8') as src: for script, modname, t, line in embedded(f, modname, src): yield script, modname.encode('utf8'), t, line def main(argv): if len(argv) < 2 or (argv[1] == '-' and len(argv) > 2): print('Usage: %s {-|file [file] [file] ...}') return 1 if argv[1] == '-': argv = argv[:1] argv.extend(l.rstrip() for l in sys.stdin.readlines()) localmodpaths = {} used_imports = {} any_errors = False for source_path in argv[1:]: modname = dotted_name_of_path(source_path) localmodpaths[modname] = source_path localmods = populateextmods(localmodpaths) for localmodname, source_path in sorted(localmodpaths.items()): if not isinstance(localmodname, bytes): # This is only safe because all hg's files are ascii localmodname = localmodname.encode('ascii') for src, modname, name, line in sources(source_path, localmodname): try: used_imports[modname] = sorted( imported_modules( src, modname, name, localmods, ignore_nested=True ) ) for error, lineno in verify_import_convention( modname, src, localmods ): any_errors = True print('%s:%d: %s' % (source_path, lineno + line, error)) except SyntaxError as e: print( '%s:%d: SyntaxError: %s' % (source_path, e.lineno + line, e) ) cycles = find_cycles(used_imports) if cycles: firstmods = set() for c in sorted(cycles, key=_cycle_sortkey): first = c.split()[0] # As a rough cut, ignore any cycle that starts with the # same module as some other cycle. Otherwise we see lots # of cycles that are effectively duplicates. if first in firstmods: continue print('Import cycle:', c) firstmods.add(first) any_errors = True return any_errors != 0 if __name__ == '__main__': sys.exit(int(main(sys.argv)))