Issue #27138: Fix the doc comment for FileFinder.find_spec().

3 files changed, 58 insertions, 33 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 9eecbfe967..afc31ee5e8 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -878,13 +878,20 @@ def _find_spec_legacy(finder, name, path):
 
 def _find_spec(name, path, target=None):
     """Find a module's loader."""
-    if sys.meta_path is not None and not sys.meta_path:
+    meta_path = sys.meta_path
+    if meta_path is None:
+        # PyImport_Cleanup() is running or has been called.
+        raise ImportError("sys.meta_path is None, Python is likely "
+                          "shutting down")
+
+    if not meta_path:
         _warnings.warn('sys.meta_path is empty', ImportWarning)
+
     # We check sys.modules here for the reload case.  While a passed-in
     # target will usually indicate a reload there is no guarantee, whereas
     # sys.modules provides one.
     is_reload = name in sys.modules
-    for finder in sys.meta_path:
+    for finder in meta_path:
         with _ImportLockContext():
             try:
                 find_spec = finder.find_spec
@@ -925,6 +932,9 @@ def _sanity_check(name, package, level):
     if level > 0:
         if not isinstance(package, str):
             raise TypeError('__package__ not set to a string')
+        elif not package:
+            raise ImportError('attempted relative import with no known parent '
+                              'package')
         elif package not in sys.modules:
             msg = ('Parent module {!r} not loaded, cannot perform relative '
                    'import')
@@ -1033,7 +1043,19 @@ def _calc___package__(globals):
 
     """
     package = globals.get('__package__')
-    if package is None:
+    spec = globals.get('__spec__')
+    if package is not None:
+        if spec is not None and package != spec.parent:
+            _warnings.warn("__package__ != __spec__.parent "
+                           f"({package!r} != {spec.parent!r})",
+                           ImportWarning, stacklevel=3)
+        return package
+    elif spec is not None:
+        return spec.parent
+    else:
+        _warnings.warn("can't resolve package from __spec__ or __package__, "
+                       "falling back on __name__ and __path__",
+                       ImportWarning, stacklevel=3)
         package = globals['__name__']
         if '__path__' not in globals:
             package = package.rpartition('.')[0]
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index 9788828688..034b783990 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -223,6 +223,9 @@ _code_type = type(_write_atomic.__code__)
 #     Python 3.5b1  3330 (PEP 448: Additional Unpacking Generalizations)
 #     Python 3.5b2  3340 (fix dictionary display evaluation order #11205)
 #     Python 3.5b2  3350 (add GET_YIELD_FROM_ITER opcode #24400)
+#     Python 3.6a0  3360 (add FORMAT_VALUE opcode #25483
+#     Python 3.6a0  3361 (lineno delta of code.co_lnotab becomes signed)
+#     Python 3.6a0  3370 (16 bit wordcode)
 #
 # MAGIC must change whenever the bytecode emitted by the compiler may no
 # longer be understood by older implementations of the eval loop (usually
@@ -231,7 +234,7 @@ _code_type = type(_write_atomic.__code__)
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3350).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3370).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 
 _PYCACHE = '__pycache__'
@@ -363,14 +366,6 @@ def _calc_mode(path):
     return mode
 
 
-def _verbose_message(message, *args, verbosity=1):
-    """Print the message to stderr if -v/PYTHONVERBOSE is turned on."""
-    if sys.flags.verbose >= verbosity:
-        if not message.startswith(('#', 'import ')):
-            message = '# ' + message
-        print(message.format(*args), file=sys.stderr)
-
-
 def _check_name(method):
     """Decorator to verify that the module being requested matches the one the
     loader can handle.
@@ -440,15 +435,15 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
     raw_size = data[8:12]
     if magic != MAGIC_NUMBER:
         message = 'bad magic number in {!r}: {!r}'.format(name, magic)
-        _verbose_message('{}', message)
+        _bootstrap._verbose_message('{}', message)
         raise ImportError(message, **exc_details)
     elif len(raw_timestamp) != 4:
         message = 'reached EOF while reading timestamp in {!r}'.format(name)
-        _verbose_message('{}', message)
+        _bootstrap._verbose_message('{}', message)
         raise EOFError(message)
     elif len(raw_size) != 4:
         message = 'reached EOF while reading size of source in {!r}'.format(name)
-        _verbose_message('{}', message)
+        _bootstrap._verbose_message('{}', message)
         raise EOFError(message)
     if source_stats is not None:
         try:
@@ -458,7 +453,7 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
         else:
             if _r_long(raw_timestamp) != source_mtime:
                 message = 'bytecode is stale for {!r}'.format(name)
-                _verbose_message('{}', message)
+                _bootstrap._verbose_message('{}', message)
                 raise ImportError(message, **exc_details)
         try:
             source_size = source_stats['size'] & 0xFFFFFFFF
@@ -475,7 +470,7 @@ def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None):
     """Compile bytecode as returned by _validate_bytecode_header()."""
     code = marshal.loads(data)
     if isinstance(code, _code_type):
-        _verbose_message('code object from {!r}', bytecode_path)
+        _bootstrap._verbose_message('code object from {!r}', bytecode_path)
         if source_path is not None:
             _imp._fix_co_filename(code, source_path)
         return code
@@ -602,7 +597,7 @@ class WindowsRegistryFinder:
         else:
             registry_key = cls.REGISTRY_KEY
         key = registry_key.format(fullname=fullname,
-                                  sys_version=sys.version[:3])
+                                  sys_version='%d.%d' % sys.version_info[:2])
         try:
             with cls._open_registry(key) as hkey:
                 filepath = _winreg.QueryValue(hkey, '')
@@ -665,6 +660,7 @@ class _LoaderBasics:
         _bootstrap._call_with_frames_removed(exec, code, module.__dict__)
 
     def load_module(self, fullname):
+        """This module is deprecated."""
         return _bootstrap._load_module_shim(self, fullname)
 
 
@@ -758,21 +754,21 @@ class SourceLoader(_LoaderBasics):
                     except (ImportError, EOFError):
                         pass
                     else:
-                        _verbose_message('{} matches {}', bytecode_path,
-                                        source_path)
+                        _bootstrap._verbose_message('{} matches {}', bytecode_path,
+                                                    source_path)
                         return _compile_bytecode(bytes_data, name=fullname,
                                                  bytecode_path=bytecode_path,
                                                  source_path=source_path)
         source_bytes = self.get_data(source_path)
         code_object = self.source_to_code(source_bytes, source_path)
-        _verbose_message('code object from {}', source_path)
+        _bootstrap._verbose_message('code object from {}', source_path)
         if (not sys.dont_write_bytecode and bytecode_path is not None and
                 source_mtime is not None):
             data = _code_to_bytecode(code_object, source_mtime,
                     len(source_bytes))
             try:
                 self._cache_bytecode(source_path, bytecode_path, data)
-                _verbose_message('wrote {!r}', bytecode_path)
+                _bootstrap._verbose_message('wrote {!r}', bytecode_path)
             except NotImplementedError:
                 pass
         return code_object
@@ -852,14 +848,16 @@ class SourceFileLoader(FileLoader, SourceLoader):
             except OSError as exc:
                 # Could be a permission error, read-only filesystem: just forget
                 # about writing the data.
-                _verbose_message('could not create {!r}: {!r}', parent, exc)
+                _bootstrap._verbose_message('could not create {!r}: {!r}',
+                                            parent, exc)
                 return
         try:
             _write_atomic(path, data, _mode)
-            _verbose_message('created {!r}', path)
+            _bootstrap._verbose_message('created {!r}', path)
         except OSError as exc:
             # Same as above: just don't write the bytecode.
-            _verbose_message('could not create {!r}: {!r}', path, exc)
+            _bootstrap._verbose_message('could not create {!r}: {!r}', path,
+                                        exc)
 
 
 class SourcelessFileLoader(FileLoader, _LoaderBasics):
@@ -904,14 +902,14 @@ class ExtensionFileLoader(FileLoader, _LoaderBasics):
         """Create an unitialized extension module"""
         module = _bootstrap._call_with_frames_removed(
             _imp.create_dynamic, spec)
-        _verbose_message('extension module {!r} loaded from {!r}',
+        _bootstrap._verbose_message('extension module {!r} loaded from {!r}',
                          spec.name, self.path)
         return module
 
     def exec_module(self, module):
         """Initialize an extension module"""
         _bootstrap._call_with_frames_removed(_imp.exec_dynamic, module)
-        _verbose_message('extension module {!r} executed from {!r}',
+        _bootstrap._verbose_message('extension module {!r} executed from {!r}',
                          self.name, self.path)
 
     def is_package(self, fullname):
@@ -977,6 +975,9 @@ class _NamespacePath:
     def __iter__(self):
         return iter(self._recalculate())
 
+    def __setitem__(self, index, path):
+        self._path[index] = path
+
     def __len__(self):
         return len(self._recalculate())
 
@@ -1026,7 +1027,8 @@ class _NamespaceLoader:
 
         """
         # The import system never calls this method.
-        _verbose_message('namespace module loaded with path {!r}', self._path)
+        _bootstrap._verbose_message('namespace module loaded with path {!r}',
+                                    self._path)
         return _bootstrap._load_module_shim(self, fullname)
 
 
@@ -1246,12 +1248,13 @@ class FileFinder:
         # Check for a file w/ a proper suffix exists.
         for suffix, loader_class in self._loaders:
             full_path = _path_join(self.path, tail_module + suffix)
-            _verbose_message('trying {}'.format(full_path), verbosity=2)
+            _bootstrap._verbose_message('trying {}', full_path, verbosity=2)
             if cache_module + suffix in cache:
                 if _path_isfile(full_path):
-                    return self._get_spec(loader_class, fullname, full_path, None, target)
+                    return self._get_spec(loader_class, fullname, full_path,
+                                          None, target)
         if is_namespace:
-            _verbose_message('possible namespace for {}'.format(base_path))
+            _bootstrap._verbose_message('possible namespace for {}', base_path)
             spec = _bootstrap.ModuleSpec(fullname, None)
             spec.submodule_search_locations = [base_path]
             return spec
diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py
index 4525b3f78e..af781fd4cd 100644
--- a/Lib/importlib/util.py
+++ b/Lib/importlib/util.py
@@ -22,8 +22,8 @@ def resolve_name(name, package):
     if not name.startswith('.'):
         return name
     elif not package:
-        raise ValueError('{!r} is not a relative name '
-                         '(no leading dot)'.format(name))
+        raise ValueError(f'no package specified for {repr(name)} '
+                         '(required for relative module names)')
     level = 0
     for character in name:
         if character != '.':