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1"""Find modules used by a script, using introspection."""
2
3import dis
4import importlib._bootstrap_external
5import importlib.machinery
6import marshal
7import os
8import io
9import sys
10
11
12LOAD_CONST = dis.opmap['LOAD_CONST']
13IMPORT_NAME = dis.opmap['IMPORT_NAME']
14STORE_NAME = dis.opmap['STORE_NAME']
15STORE_GLOBAL = dis.opmap['STORE_GLOBAL']
16STORE_OPS = STORE_NAME, STORE_GLOBAL
17EXTENDED_ARG = dis.EXTENDED_ARG
18
19# Old imp constants:
20
21_SEARCH_ERROR = 0
22_PY_SOURCE = 1
23_PY_COMPILED = 2
24_C_EXTENSION = 3
25_PKG_DIRECTORY = 5
26_C_BUILTIN = 6
27_PY_FROZEN = 7
28
29# Modulefinder does a good job at simulating Python's, but it can not
30# handle __path__ modifications packages make at runtime.  Therefore there
31# is a mechanism whereby you can register extra paths in this map for a
32# package, and it will be honored.
33
34# Note this is a mapping is lists of paths.
35packagePathMap = {}
36
37# A Public interface
38def AddPackagePath(packagename, path):
39    packagePathMap.setdefault(packagename, []).append(path)
40
41replacePackageMap = {}
42
43# This ReplacePackage mechanism allows modulefinder to work around
44# situations in which a package injects itself under the name
45# of another package into sys.modules at runtime by calling
46# ReplacePackage("real_package_name", "faked_package_name")
47# before running ModuleFinder.
48
49def ReplacePackage(oldname, newname):
50    replacePackageMap[oldname] = newname
51
52
53def _find_module(name, path=None):
54    """An importlib reimplementation of imp.find_module (for our purposes)."""
55
56    # It's necessary to clear the caches for our Finder first, in case any
57    # modules are being added/deleted/modified at runtime. In particular,
58    # test_modulefinder.py changes file tree contents in a cache-breaking way:
59
60    importlib.machinery.PathFinder.invalidate_caches()
61
62    spec = importlib.machinery.PathFinder.find_spec(name, path)
63
64    if spec is None:
65        raise ImportError("No module named {name!r}".format(name=name), name=name)
66
67    # Some special cases:
68
69    if spec.loader is importlib.machinery.BuiltinImporter:
70        return None, None, ("", "", _C_BUILTIN)
71
72    if spec.loader is importlib.machinery.FrozenImporter:
73        return None, None, ("", "", _PY_FROZEN)
74
75    file_path = spec.origin
76
77    if spec.loader.is_package(name):
78        return None, os.path.dirname(file_path), ("", "", _PKG_DIRECTORY)
79
80    if isinstance(spec.loader, importlib.machinery.SourceFileLoader):
81        kind = _PY_SOURCE
82
83    elif isinstance(spec.loader, importlib.machinery.ExtensionFileLoader):
84        kind = _C_EXTENSION
85
86    elif isinstance(spec.loader, importlib.machinery.SourcelessFileLoader):
87        kind = _PY_COMPILED
88
89    else:  # Should never happen.
90        return None, None, ("", "", _SEARCH_ERROR)
91
92    file = io.open_code(file_path)
93    suffix = os.path.splitext(file_path)[-1]
94
95    return file, file_path, (suffix, "rb", kind)
96
97
98class Module:
99
100    def __init__(self, name, file=None, path=None):
101        self.__name__ = name
102        self.__file__ = file
103        self.__path__ = path
104        self.__code__ = None
105        # The set of global names that are assigned to in the module.
106        # This includes those names imported through starimports of
107        # Python modules.
108        self.globalnames = {}
109        # The set of starimports this module did that could not be
110        # resolved, ie. a starimport from a non-Python module.
111        self.starimports = {}
112
113    def __repr__(self):
114        s = "Module(%r" % (self.__name__,)
115        if self.__file__ is not None:
116            s = s + ", %r" % (self.__file__,)
117        if self.__path__ is not None:
118            s = s + ", %r" % (self.__path__,)
119        s = s + ")"
120        return s
121
122class ModuleFinder:
123
124    def __init__(self, path=None, debug=0, excludes=None, replace_paths=None):
125        if path is None:
126            path = sys.path
127        self.path = path
128        self.modules = {}
129        self.badmodules = {}
130        self.debug = debug
131        self.indent = 0
132        self.excludes = excludes if excludes is not None else []
133        self.replace_paths = replace_paths if replace_paths is not None else []
134        self.processed_paths = []   # Used in debugging only
135
136    def msg(self, level, str, *args):
137        if level <= self.debug:
138            for i in range(self.indent):
139                print("   ", end=' ')
140            print(str, end=' ')
141            for arg in args:
142                print(repr(arg), end=' ')
143            print()
144
145    def msgin(self, *args):
146        level = args[0]
147        if level <= self.debug:
148            self.indent = self.indent + 1
149            self.msg(*args)
150
151    def msgout(self, *args):
152        level = args[0]
153        if level <= self.debug:
154            self.indent = self.indent - 1
155            self.msg(*args)
156
157    def run_script(self, pathname):
158        self.msg(2, "run_script", pathname)
159        with io.open_code(pathname) as fp:
160            stuff = ("", "rb", _PY_SOURCE)
161            self.load_module('__main__', fp, pathname, stuff)
162
163    def load_file(self, pathname):
164        dir, name = os.path.split(pathname)
165        name, ext = os.path.splitext(name)
166        with io.open_code(pathname) as fp:
167            stuff = (ext, "rb", _PY_SOURCE)
168            self.load_module(name, fp, pathname, stuff)
169
170    def import_hook(self, name, caller=None, fromlist=None, level=-1):
171        self.msg(3, "import_hook", name, caller, fromlist, level)
172        parent = self.determine_parent(caller, level=level)
173        q, tail = self.find_head_package(parent, name)
174        m = self.load_tail(q, tail)
175        if not fromlist:
176            return q
177        if m.__path__:
178            self.ensure_fromlist(m, fromlist)
179        return None
180
181    def determine_parent(self, caller, level=-1):
182        self.msgin(4, "determine_parent", caller, level)
183        if not caller or level == 0:
184            self.msgout(4, "determine_parent -> None")
185            return None
186        pname = caller.__name__
187        if level >= 1: # relative import
188            if caller.__path__:
189                level -= 1
190            if level == 0:
191                parent = self.modules[pname]
192                assert parent is caller
193                self.msgout(4, "determine_parent ->", parent)
194                return parent
195            if pname.count(".") < level:
196                raise ImportError("relative importpath too deep")
197            pname = ".".join(pname.split(".")[:-level])
198            parent = self.modules[pname]
199            self.msgout(4, "determine_parent ->", parent)
200            return parent
201        if caller.__path__:
202            parent = self.modules[pname]
203            assert caller is parent
204            self.msgout(4, "determine_parent ->", parent)
205            return parent
206        if '.' in pname:
207            i = pname.rfind('.')
208            pname = pname[:i]
209            parent = self.modules[pname]
210            assert parent.__name__ == pname
211            self.msgout(4, "determine_parent ->", parent)
212            return parent
213        self.msgout(4, "determine_parent -> None")
214        return None
215
216    def find_head_package(self, parent, name):
217        self.msgin(4, "find_head_package", parent, name)
218        if '.' in name:
219            i = name.find('.')
220            head = name[:i]
221            tail = name[i+1:]
222        else:
223            head = name
224            tail = ""
225        if parent:
226            qname = "%s.%s" % (parent.__name__, head)
227        else:
228            qname = head
229        q = self.import_module(head, qname, parent)
230        if q:
231            self.msgout(4, "find_head_package ->", (q, tail))
232            return q, tail
233        if parent:
234            qname = head
235            parent = None
236            q = self.import_module(head, qname, parent)
237            if q:
238                self.msgout(4, "find_head_package ->", (q, tail))
239                return q, tail
240        self.msgout(4, "raise ImportError: No module named", qname)
241        raise ImportError("No module named " + qname)
242
243    def load_tail(self, q, tail):
244        self.msgin(4, "load_tail", q, tail)
245        m = q
246        while tail:
247            i = tail.find('.')
248            if i < 0: i = len(tail)
249            head, tail = tail[:i], tail[i+1:]
250            mname = "%s.%s" % (m.__name__, head)
251            m = self.import_module(head, mname, m)
252            if not m:
253                self.msgout(4, "raise ImportError: No module named", mname)
254                raise ImportError("No module named " + mname)
255        self.msgout(4, "load_tail ->", m)
256        return m
257
258    def ensure_fromlist(self, m, fromlist, recursive=0):
259        self.msg(4, "ensure_fromlist", m, fromlist, recursive)
260        for sub in fromlist:
261            if sub == "*":
262                if not recursive:
263                    all = self.find_all_submodules(m)
264                    if all:
265                        self.ensure_fromlist(m, all, 1)
266            elif not hasattr(m, sub):
267                subname = "%s.%s" % (m.__name__, sub)
268                submod = self.import_module(sub, subname, m)
269                if not submod:
270                    raise ImportError("No module named " + subname)
271
272    def find_all_submodules(self, m):
273        if not m.__path__:
274            return
275        modules = {}
276        # 'suffixes' used to be a list hardcoded to [".py", ".pyc"].
277        # But we must also collect Python extension modules - although
278        # we cannot separate normal dlls from Python extensions.
279        suffixes = []
280        suffixes += importlib.machinery.EXTENSION_SUFFIXES[:]
281        suffixes += importlib.machinery.SOURCE_SUFFIXES[:]
282        suffixes += importlib.machinery.BYTECODE_SUFFIXES[:]
283        for dir in m.__path__:
284            try:
285                names = os.listdir(dir)
286            except OSError:
287                self.msg(2, "can't list directory", dir)
288                continue
289            for name in names:
290                mod = None
291                for suff in suffixes:
292                    n = len(suff)
293                    if name[-n:] == suff:
294                        mod = name[:-n]
295                        break
296                if mod and mod != "__init__":
297                    modules[mod] = mod
298        return modules.keys()
299
300    def import_module(self, partname, fqname, parent):
301        self.msgin(3, "import_module", partname, fqname, parent)
302        try:
303            m = self.modules[fqname]
304        except KeyError:
305            pass
306        else:
307            self.msgout(3, "import_module ->", m)
308            return m
309        if fqname in self.badmodules:
310            self.msgout(3, "import_module -> None")
311            return None
312        if parent and parent.__path__ is None:
313            self.msgout(3, "import_module -> None")
314            return None
315        try:
316            fp, pathname, stuff = self.find_module(partname,
317                                                   parent and parent.__path__, parent)
318        except ImportError:
319            self.msgout(3, "import_module ->", None)
320            return None
321
322        try:
323            m = self.load_module(fqname, fp, pathname, stuff)
324        finally:
325            if fp:
326                fp.close()
327        if parent:
328            setattr(parent, partname, m)
329        self.msgout(3, "import_module ->", m)
330        return m
331
332    def load_module(self, fqname, fp, pathname, file_info):
333        suffix, mode, type = file_info
334        self.msgin(2, "load_module", fqname, fp and "fp", pathname)
335        if type == _PKG_DIRECTORY:
336            m = self.load_package(fqname, pathname)
337            self.msgout(2, "load_module ->", m)
338            return m
339        if type == _PY_SOURCE:
340            co = compile(fp.read(), pathname, 'exec')
341        elif type == _PY_COMPILED:
342            try:
343                data = fp.read()
344                importlib._bootstrap_external._classify_pyc(data, fqname, {})
345            except ImportError as exc:
346                self.msgout(2, "raise ImportError: " + str(exc), pathname)
347                raise
348            co = marshal.loads(memoryview(data)[16:])
349        else:
350            co = None
351        m = self.add_module(fqname)
352        m.__file__ = pathname
353        if co:
354            if self.replace_paths:
355                co = self.replace_paths_in_code(co)
356            m.__code__ = co
357            self.scan_code(co, m)
358        self.msgout(2, "load_module ->", m)
359        return m
360
361    def _add_badmodule(self, name, caller):
362        if name not in self.badmodules:
363            self.badmodules[name] = {}
364        if caller:
365            self.badmodules[name][caller.__name__] = 1
366        else:
367            self.badmodules[name]["-"] = 1
368
369    def _safe_import_hook(self, name, caller, fromlist, level=-1):
370        # wrapper for self.import_hook() that won't raise ImportError
371        if name in self.badmodules:
372            self._add_badmodule(name, caller)
373            return
374        try:
375            self.import_hook(name, caller, level=level)
376        except ImportError as msg:
377            self.msg(2, "ImportError:", str(msg))
378            self._add_badmodule(name, caller)
379        except SyntaxError as msg:
380            self.msg(2, "SyntaxError:", str(msg))
381            self._add_badmodule(name, caller)
382        else:
383            if fromlist:
384                for sub in fromlist:
385                    fullname = name + "." + sub
386                    if fullname in self.badmodules:
387                        self._add_badmodule(fullname, caller)
388                        continue
389                    try:
390                        self.import_hook(name, caller, [sub], level=level)
391                    except ImportError as msg:
392                        self.msg(2, "ImportError:", str(msg))
393                        self._add_badmodule(fullname, caller)
394
395    def scan_opcodes(self, co):
396        # Scan the code, and yield 'interesting' opcode combinations
397        code = co.co_code
398        names = co.co_names
399        consts = co.co_consts
400        opargs = [(op, arg) for _, op, arg in dis._unpack_opargs(code)
401                  if op != EXTENDED_ARG]
402        for i, (op, oparg) in enumerate(opargs):
403            if op in STORE_OPS:
404                yield "store", (names[oparg],)
405                continue
406            if (op == IMPORT_NAME and i >= 2
407                    and opargs[i-1][0] == opargs[i-2][0] == LOAD_CONST):
408                level = consts[opargs[i-2][1]]
409                fromlist = consts[opargs[i-1][1]]
410                if level == 0: # absolute import
411                    yield "absolute_import", (fromlist, names[oparg])
412                else: # relative import
413                    yield "relative_import", (level, fromlist, names[oparg])
414                continue
415
416    def scan_code(self, co, m):
417        code = co.co_code
418        scanner = self.scan_opcodes
419        for what, args in scanner(co):
420            if what == "store":
421                name, = args
422                m.globalnames[name] = 1
423            elif what == "absolute_import":
424                fromlist, name = args
425                have_star = 0
426                if fromlist is not None:
427                    if "*" in fromlist:
428                        have_star = 1
429                    fromlist = [f for f in fromlist if f != "*"]
430                self._safe_import_hook(name, m, fromlist, level=0)
431                if have_star:
432                    # We've encountered an "import *". If it is a Python module,
433                    # the code has already been parsed and we can suck out the
434                    # global names.
435                    mm = None
436                    if m.__path__:
437                        # At this point we don't know whether 'name' is a
438                        # submodule of 'm' or a global module. Let's just try
439                        # the full name first.
440                        mm = self.modules.get(m.__name__ + "." + name)
441                    if mm is None:
442                        mm = self.modules.get(name)
443                    if mm is not None:
444                        m.globalnames.update(mm.globalnames)
445                        m.starimports.update(mm.starimports)
446                        if mm.__code__ is None:
447                            m.starimports[name] = 1
448                    else:
449                        m.starimports[name] = 1
450            elif what == "relative_import":
451                level, fromlist, name = args
452                if name:
453                    self._safe_import_hook(name, m, fromlist, level=level)
454                else:
455                    parent = self.determine_parent(m, level=level)
456                    self._safe_import_hook(parent.__name__, None, fromlist, level=0)
457            else:
458                # We don't expect anything else from the generator.
459                raise RuntimeError(what)
460
461        for c in co.co_consts:
462            if isinstance(c, type(co)):
463                self.scan_code(c, m)
464
465    def load_package(self, fqname, pathname):
466        self.msgin(2, "load_package", fqname, pathname)
467        newname = replacePackageMap.get(fqname)
468        if newname:
469            fqname = newname
470        m = self.add_module(fqname)
471        m.__file__ = pathname
472        m.__path__ = [pathname]
473
474        # As per comment at top of file, simulate runtime __path__ additions.
475        m.__path__ = m.__path__ + packagePathMap.get(fqname, [])
476
477        fp, buf, stuff = self.find_module("__init__", m.__path__)
478        try:
479            self.load_module(fqname, fp, buf, stuff)
480            self.msgout(2, "load_package ->", m)
481            return m
482        finally:
483            if fp:
484                fp.close()
485
486    def add_module(self, fqname):
487        if fqname in self.modules:
488            return self.modules[fqname]
489        self.modules[fqname] = m = Module(fqname)
490        return m
491
492    def find_module(self, name, path, parent=None):
493        if parent is not None:
494            # assert path is not None
495            fullname = parent.__name__+'.'+name
496        else:
497            fullname = name
498        if fullname in self.excludes:
499            self.msgout(3, "find_module -> Excluded", fullname)
500            raise ImportError(name)
501
502        if path is None:
503            if name in sys.builtin_module_names:
504                return (None, None, ("", "", _C_BUILTIN))
505
506            path = self.path
507
508        return _find_module(name, path)
509
510    def report(self):
511        """Print a report to stdout, listing the found modules with their
512        paths, as well as modules that are missing, or seem to be missing.
513        """
514        print()
515        print("  %-25s %s" % ("Name", "File"))
516        print("  %-25s %s" % ("----", "----"))
517        # Print modules found
518        keys = sorted(self.modules.keys())
519        for key in keys:
520            m = self.modules[key]
521            if m.__path__:
522                print("P", end=' ')
523            else:
524                print("m", end=' ')
525            print("%-25s" % key, m.__file__ or "")
526
527        # Print missing modules
528        missing, maybe = self.any_missing_maybe()
529        if missing:
530            print()
531            print("Missing modules:")
532            for name in missing:
533                mods = sorted(self.badmodules[name].keys())
534                print("?", name, "imported from", ', '.join(mods))
535        # Print modules that may be missing, but then again, maybe not...
536        if maybe:
537            print()
538            print("Submodules that appear to be missing, but could also be", end=' ')
539            print("global names in the parent package:")
540            for name in maybe:
541                mods = sorted(self.badmodules[name].keys())
542                print("?", name, "imported from", ', '.join(mods))
543
544    def any_missing(self):
545        """Return a list of modules that appear to be missing. Use
546        any_missing_maybe() if you want to know which modules are
547        certain to be missing, and which *may* be missing.
548        """
549        missing, maybe = self.any_missing_maybe()
550        return missing + maybe
551
552    def any_missing_maybe(self):
553        """Return two lists, one with modules that are certainly missing
554        and one with modules that *may* be missing. The latter names could
555        either be submodules *or* just global names in the package.
556
557        The reason it can't always be determined is that it's impossible to
558        tell which names are imported when "from module import *" is done
559        with an extension module, short of actually importing it.
560        """
561        missing = []
562        maybe = []
563        for name in self.badmodules:
564            if name in self.excludes:
565                continue
566            i = name.rfind(".")
567            if i < 0:
568                missing.append(name)
569                continue
570            subname = name[i+1:]
571            pkgname = name[:i]
572            pkg = self.modules.get(pkgname)
573            if pkg is not None:
574                if pkgname in self.badmodules[name]:
575                    # The package tried to import this module itself and
576                    # failed. It's definitely missing.
577                    missing.append(name)
578                elif subname in pkg.globalnames:
579                    # It's a global in the package: definitely not missing.
580                    pass
581                elif pkg.starimports:
582                    # It could be missing, but the package did an "import *"
583                    # from a non-Python module, so we simply can't be sure.
584                    maybe.append(name)
585                else:
586                    # It's not a global in the package, the package didn't
587                    # do funny star imports, it's very likely to be missing.
588                    # The symbol could be inserted into the package from the
589                    # outside, but since that's not good style we simply list
590                    # it missing.
591                    missing.append(name)
592            else:
593                missing.append(name)
594        missing.sort()
595        maybe.sort()
596        return missing, maybe
597
598    def replace_paths_in_code(self, co):
599        new_filename = original_filename = os.path.normpath(co.co_filename)
600        for f, r in self.replace_paths:
601            if original_filename.startswith(f):
602                new_filename = r + original_filename[len(f):]
603                break
604
605        if self.debug and original_filename not in self.processed_paths:
606            if new_filename != original_filename:
607                self.msgout(2, "co_filename %r changed to %r" \
608                                    % (original_filename,new_filename,))
609            else:
610                self.msgout(2, "co_filename %r remains unchanged" \
611                                    % (original_filename,))
612            self.processed_paths.append(original_filename)
613
614        consts = list(co.co_consts)
615        for i in range(len(consts)):
616            if isinstance(consts[i], type(co)):
617                consts[i] = self.replace_paths_in_code(consts[i])
618
619        return co.replace(co_consts=tuple(consts), co_filename=new_filename)
620
621
622def test():
623    # Parse command line
624    import getopt
625    try:
626        opts, args = getopt.getopt(sys.argv[1:], "dmp:qx:")
627    except getopt.error as msg:
628        print(msg)
629        return
630
631    # Process options
632    debug = 1
633    domods = 0
634    addpath = []
635    exclude = []
636    for o, a in opts:
637        if o == '-d':
638            debug = debug + 1
639        if o == '-m':
640            domods = 1
641        if o == '-p':
642            addpath = addpath + a.split(os.pathsep)
643        if o == '-q':
644            debug = 0
645        if o == '-x':
646            exclude.append(a)
647
648    # Provide default arguments
649    if not args:
650        script = "hello.py"
651    else:
652        script = args[0]
653
654    # Set the path based on sys.path and the script directory
655    path = sys.path[:]
656    path[0] = os.path.dirname(script)
657    path = addpath + path
658    if debug > 1:
659        print("path:")
660        for item in path:
661            print("   ", repr(item))
662
663    # Create the module finder and turn its crank
664    mf = ModuleFinder(path, debug, exclude)
665    for arg in args[1:]:
666        if arg == '-m':
667            domods = 1
668            continue
669        if domods:
670            if arg[-2:] == '.*':
671                mf.import_hook(arg[:-2], None, ["*"])
672            else:
673                mf.import_hook(arg)
674        else:
675            mf.load_file(arg)
676    mf.run_script(script)
677    mf.report()
678    return mf  # for -i debugging
679
680
681if __name__ == '__main__':
682    try:
683        mf = test()
684    except KeyboardInterrupt:
685        print("\n[interrupted]")
686