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