Merge pull request #857 from pkolbus/remove-imp

Remove dependency on imp.
Many thanks @pkolbus and @degustaf !

8 files changed, 115 insertions, 141 deletions

diff --git a/ChangeLog b/ChangeLog
index 27a61f00..03b12780 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -59,6 +59,11 @@ Release Date: TBA
 
 * Reduce memory usage of astroid's module cache.
 
+* Remove dependency on `imp`.
+
+  Close #594
+  Close #681
+
 What's New in astroid 2.4.3?
 ============================
 Release Date: TBA
diff --git a/astroid/interpreter/_import/spec.py b/astroid/interpreter/_import/spec.py
index 26e22b5d..125f9a16 100644
--- a/astroid/interpreter/_import/spec.py
+++ b/astroid/interpreter/_import/spec.py
@@ -12,17 +12,11 @@ import abc
 import collections
 import distutils
 import enum
-import imp
 import os
 import sys
 import zipimport
 
-try:
-    import importlib.machinery
-
-    _HAS_MACHINERY = True
-except ImportError:
-    _HAS_MACHINERY = False
+import importlib.machinery
 
 try:
     from functools import lru_cache
@@ -37,22 +31,6 @@ ModuleType = enum.Enum(
     "PY_CODERESOURCE PY_COMPILED PY_FROZEN PY_RESOURCE "
     "PY_SOURCE PY_ZIPMODULE PY_NAMESPACE",
 )
-_ImpTypes = {
-    imp.C_BUILTIN: ModuleType.C_BUILTIN,
-    imp.C_EXTENSION: ModuleType.C_EXTENSION,
-    imp.PKG_DIRECTORY: ModuleType.PKG_DIRECTORY,
-    imp.PY_COMPILED: ModuleType.PY_COMPILED,
-    imp.PY_FROZEN: ModuleType.PY_FROZEN,
-    imp.PY_SOURCE: ModuleType.PY_SOURCE,
-}
-if hasattr(imp, "PY_RESOURCE"):
-    _ImpTypes[imp.PY_RESOURCE] = ModuleType.PY_RESOURCE
-if hasattr(imp, "PY_CODERESOURCE"):
-    _ImpTypes[imp.PY_CODERESOURCE] = ModuleType.PY_CODERESOURCE
-
-
-def _imp_type_to_module_type(imp_type):
-    return _ImpTypes[imp_type]
 
 
 _ModuleSpec = collections.namedtuple(
@@ -114,26 +92,59 @@ class Finder:
         """Get a list of extra paths where this finder can search."""
 
 
-class ImpFinder(Finder):
-    """A finder based on the imp module."""
+class ImportlibFinder(Finder):
+    """A finder based on the importlib module."""
+
+    _SUFFIXES = (
+        [(s, ModuleType.C_EXTENSION) for s in importlib.machinery.EXTENSION_SUFFIXES]
+        + [(s, ModuleType.PY_SOURCE) for s in importlib.machinery.SOURCE_SUFFIXES]
+        + [(s, ModuleType.PY_COMPILED) for s in importlib.machinery.BYTECODE_SUFFIXES]
+    )
 
     def find_module(self, modname, module_parts, processed, submodule_path):
+        if not isinstance(modname, str):
+            raise TypeError("'modname' must be a str, not {}".format(type(modname)))
         if submodule_path is not None:
             submodule_path = list(submodule_path)
-        try:
-            stream, mp_filename, mp_desc = imp.find_module(modname, submodule_path)
-        except ImportError:
-            return None
-
-        # Close resources.
-        if stream:
-            stream.close()
-
-        return ModuleSpec(
-            name=modname,
-            location=mp_filename,
-            module_type=_imp_type_to_module_type(mp_desc[2]),
-        )
+        else:
+            try:
+                spec = importlib.util.find_spec(modname)
+                if spec:
+                    if spec.loader is importlib.machinery.BuiltinImporter:
+                        return ModuleSpec(
+                            name=modname,
+                            location=None,
+                            module_type=ModuleType.C_BUILTIN,
+                        )
+                    if spec.loader is importlib.machinery.FrozenImporter:
+                        return ModuleSpec(
+                            name=modname,
+                            location=None,
+                            module_type=ModuleType.PY_FROZEN,
+                        )
+            except ValueError:
+                pass
+            submodule_path = sys.path
+
+        for entry in submodule_path:
+            package_directory = os.path.join(entry, modname)
+            for suffix in [".py", importlib.machinery.BYTECODE_SUFFIXES[0]]:
+                package_file_name = "__init__" + suffix
+                file_path = os.path.join(package_directory, package_file_name)
+                if os.path.isfile(file_path):
+                    return ModuleSpec(
+                        name=modname,
+                        location=package_directory,
+                        module_type=ModuleType.PKG_DIRECTORY,
+                    )
+            for suffix, type_ in ImportlibFinder._SUFFIXES:
+                file_name = modname + suffix
+                file_path = os.path.join(entry, file_name)
+                if os.path.isfile(file_path):
+                    return ModuleSpec(
+                        name=modname, location=file_path, module_type=type_
+                    )
+        return None
 
     def contribute_to_path(self, spec, processed):
         if spec.location is None:
@@ -159,7 +170,7 @@ class ImpFinder(Finder):
         return path
 
 
-class ExplicitNamespacePackageFinder(ImpFinder):
+class ExplicitNamespacePackageFinder(ImportlibFinder):
     """A finder for the explicit namespace packages, generated through pkg_resources."""
 
     def find_module(self, modname, module_parts, processed, submodule_path):
@@ -229,10 +240,12 @@ class PathSpecFinder(Finder):
         return None
 
 
-_SPEC_FINDERS = (ImpFinder, ZipFinder)
-if _HAS_MACHINERY:
-    _SPEC_FINDERS += (PathSpecFinder,)
-_SPEC_FINDERS += (ExplicitNamespacePackageFinder,)
+_SPEC_FINDERS = (
+    ImportlibFinder,
+    ZipFinder,
+    PathSpecFinder,
+    ExplicitNamespacePackageFinder,
+)
 
 
 def _is_setuptools_namespace(location):
diff --git a/astroid/modutils.py b/astroid/modutils.py
index 4e6ed86b..4fe0bd5e 100644
--- a/astroid/modutils.py
+++ b/astroid/modutils.py
@@ -31,7 +31,7 @@
 :type BUILTIN_MODULES: dict
 :var BUILTIN_MODULES: dictionary with builtin module names has key
 """
-import imp
+import importlib.util
 import os
 import platform
 import sys
@@ -44,7 +44,6 @@ from distutils.errors import DistutilsPlatformError
 # distutils is replaced by virtualenv with a module that does
 # weird path manipulations in order to get to the
 # real distutils module.
-from typing import Optional, List
 
 from .interpreter._import import spec
 from .interpreter._import import util
@@ -178,110 +177,53 @@ def _cache_normalize_path(path):
         return result
 
 
-def load_module_from_name(dotted_name, path=None, use_sys=True):
+def load_module_from_name(dotted_name):
     """Load a Python module from its name.
 
     :type dotted_name: str
     :param dotted_name: python name of a module or package
 
-    :type path: list or None
-    :param path:
-      optional list of path where the module or package should be
-      searched (use sys.path if nothing or None is given)
-
-    :type use_sys: bool
-    :param use_sys:
-      boolean indicating whether the sys.modules dictionary should be
-      used or not
-
-
     :raise ImportError: if the module or package is not found
 
     :rtype: module
     :return: the loaded module
     """
-    return load_module_from_modpath(dotted_name.split("."), path, use_sys)
+    try:
+        return sys.modules[dotted_name]
+    except KeyError:
+        pass
 
+    return importlib.import_module(dotted_name)
 
-def load_module_from_modpath(parts, path: Optional[List[str]] = None, use_sys=1):
+
+def load_module_from_modpath(parts):
     """Load a python module from its split name.
 
     :type parts: list(str) or tuple(str)
     :param parts:
       python name of a module or package split on '.'
 
-    :param path:
-      Optional list of path where the module or package should be
-      searched (use sys.path if nothing or None is given)
-
-    :type use_sys: bool
-    :param use_sys:
-      boolean indicating whether the sys.modules dictionary should be used or not
-
     :raise ImportError: if the module or package is not found
 
     :rtype: module
     :return: the loaded module
     """
-    if use_sys:
-        try:
-            return sys.modules[".".join(parts)]
-        except KeyError:
-            pass
-    modpath = []
-    prevmodule = None
-    for part in parts:
-        modpath.append(part)
-        curname = ".".join(modpath)
-        module = None
-        if len(modpath) != len(parts):
-            # even with use_sys=False, should try to get outer packages from sys.modules
-            module = sys.modules.get(curname)
-        elif use_sys:
-            # because it may have been indirectly loaded through a parent
-            module = sys.modules.get(curname)
-        if module is None:
-            mp_file, mp_filename, mp_desc = imp.find_module(part, path)
-            module = imp.load_module(curname, mp_file, mp_filename, mp_desc)
-            # mp_file still needs to be closed.
-            if mp_file:
-                mp_file.close()
-        if prevmodule:
-            setattr(prevmodule, part, module)
-        _file = getattr(module, "__file__", "")
-        prevmodule = module
-        if not _file and util.is_namespace(curname):
-            continue
-        if not _file and len(modpath) != len(parts):
-            raise ImportError("no module in %s" % ".".join(parts[len(modpath) :]))
-        path = [os.path.dirname(_file)]
-    return module
+    return load_module_from_name(".".join(parts))
 
 
-def load_module_from_file(
-    filepath: str, path: Optional[List[str]] = None, use_sys=True
-):
+def load_module_from_file(filepath: str):
     """Load a Python module from it's path.
 
     :type filepath: str
     :param filepath: path to the python module or package
 
-    :param Optional[List[str]] path:
-      Optional list of path where the module or package should be
-      searched (use sys.path if nothing or None is given)
-
-    :type use_sys: bool
-    :param use_sys:
-      boolean indicating whether the sys.modules dictionary should be
-      used or not
-
     :raise ImportError: if the module or package is not found
 
     :rtype: module
     :return: the loaded module
     """
     modpath = modpath_from_file(filepath)
-    return load_module_from_modpath(modpath, path, use_sys)
+    return load_module_from_modpath(modpath)
 
 
 def check_modpath_has_init(path, mod_path):
@@ -418,7 +360,9 @@ def file_info_from_modpath(modpath, path=None, context_file=None):
     elif modpath == ["os", "path"]:
         # FIXME: currently ignoring search_path...
         return spec.ModuleSpec(
-            name="os.path", location=os.path.__file__, module_type=imp.PY_SOURCE
+            name="os.path",
+            location=os.path.__file__,
+            module_type=spec.ModuleType.PY_SOURCE,
         )
     return _spec_from_modpath(modpath, path, context)
 
@@ -614,16 +558,22 @@ def is_relative(modname, from_file):
         from_file = os.path.dirname(from_file)
     if from_file in sys.path:
         return False
-    try:
-        stream, _, _ = imp.find_module(modname.split(".")[0], [from_file])
-
-        # Close the stream to avoid ResourceWarnings.
-        if stream:
-            stream.close()
-        return True
-    except ImportError:
+    name = os.path.basename(from_file)
+    file_path = os.path.dirname(from_file)
+    parent_spec = importlib.util.find_spec(name, from_file)
+    while parent_spec is None and len(file_path) > 0:
+        name = os.path.basename(file_path) + "." + name
+        file_path = os.path.dirname(file_path)
+        parent_spec = importlib.util.find_spec(name, from_file)
+
+    if parent_spec is None:
         return False
 
+    submodule_spec = importlib.util.find_spec(
+        name + "." + modname.split(".")[0], parent_spec.submodule_search_locations
+    )
+    return submodule_spec is not None
+
 
 # internal only functions #####################################################
 
diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index a44e6282..8680e628 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -1448,6 +1448,7 @@ class FunctionDef(mixins.MultiLineBlockMixin, node_classes.Statement, Lambda):
                             decorators.append(assign.value)
         return decorators
 
+    # pylint: disable=invalid-overridden-method
     @decorators_mod.cachedproperty
     def type(
         self
diff --git a/tests/testdata/python3/data/nonregr.py b/tests/testdata/python3/data/nonregr.py
index 78765c85..073135d2 100644
--- a/tests/testdata/python3/data/nonregr.py
+++ b/tests/testdata/python3/data/nonregr.py
@@ -16,9 +16,7 @@ def toto(value):
         print(v.get('yo'))
 
 
-import imp
-fp, mpath, desc = imp.find_module('optparse',a)
-s_opt = imp.load_module('std_optparse', fp, mpath, desc)
+import optparse as s_opt
 
 class OptionParser(s_opt.OptionParser):
 
diff --git a/tests/unittest_brain.py b/tests/unittest_brain.py
index c308ddd5..b42fa03f 100644
--- a/tests/unittest_brain.py
+++ b/tests/unittest_brain.py
@@ -540,8 +540,10 @@ class MultiprocessingBrainTest(unittest.TestCase):
             obj = next(module[attr].infer())
             self.assertEqual(obj.qname(), "{}.{}".format(bases.BUILTINS, attr))
 
-        array = next(module["array"].infer())
-        self.assertEqual(array.qname(), "array.array")
+        # pypy's implementation of array.__spec__ return None. This causes problems for this inference.
+        if not hasattr(sys, "pypy_version_info"):
+            array = next(module["array"].infer())
+            self.assertEqual(array.qname(), "array.array")
 
         manager = next(module["manager"].infer())
         # Verify that we have these attributes
diff --git a/tests/unittest_inference.py b/tests/unittest_inference.py
index b7bc732d..23a131e4 100644
--- a/tests/unittest_inference.py
+++ b/tests/unittest_inference.py
@@ -541,18 +541,6 @@ class InferenceTest(resources.SysPathSetup, unittest.TestCase):
         self.assertEqual(ancestor.root().name, BUILTINS)
         self.assertRaises(StopIteration, partial(next, ancestors))
 
-    def test_qqch(self):
-        code = """
-            from astroid.modutils import load_module_from_name
-            xxx = load_module_from_name('__pkginfo__')
-        """
-        ast = parse(code, __name__)
-        xxx = ast["xxx"]
-        self.assertSetEqual(
-            {n.__class__ for n in xxx.inferred()},
-            {nodes.Const, util.Uninferable.__class__},
-        )
-
     def test_method_argument(self):
         code = '''
             class ErudiEntitySchema:
diff --git a/tests/unittest_modutils.py b/tests/unittest_modutils.py
index b5c41bf0..460bc93f 100644
--- a/tests/unittest_modutils.py
+++ b/tests/unittest_modutils.py
@@ -82,7 +82,7 @@ class LoadModuleFromNameTest(unittest.TestCase):
 
     def test_raise_load_module_from_name_1(self):
         self.assertRaises(
-            ImportError, modutils.load_module_from_name, "os.path", use_sys=0
+            ImportError, modutils.load_module_from_name, "_this_module_does_not_exist_"
         )
 
 
@@ -297,6 +297,23 @@ class IsRelativeTest(unittest.TestCase):
     def test_knownValues_is_relative_3(self):
         self.assertFalse(modutils.is_relative("astroid", astroid.__path__[0]))
 
+    def test_deep_relative(self):
+        self.assertTrue(modutils.is_relative("ElementTree", xml.etree.__path__[0]))
+
+    def test_deep_relative2(self):
+        self.assertFalse(modutils.is_relative("ElementTree", xml.__path__[0]))
+
+    def test_deep_relative3(self):
+        self.assertTrue(modutils.is_relative("etree.ElementTree", xml.__path__[0]))
+
+    def test_deep_relative4(self):
+        self.assertTrue(modutils.is_relative("etree.gibberish", xml.__path__[0]))
+
+    def test_is_relative_bad_path(self):
+        self.assertFalse(
+            modutils.is_relative("ElementTree", os.path.join(xml.__path__[0], "ftree"))
+        )
+
 
 class GetModuleFilesTest(unittest.TestCase):
     def test_get_module_files_1(self):