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