1 files changed, 37 insertions, 27 deletions

diff --git a/Lib/lib2to3/fixes/fix_imports.py b/Lib/lib2to3/fixes/fix_imports.py
index 38e868b..e48c4f0 100644
--- a/Lib/lib2to3/fixes/fix_imports.py
+++ b/Lib/lib2to3/fixes/fix_imports.py
@@ -1,9 +1,9 @@
 """Fix incompatible imports and module references."""
-# Author: Collin Winter
+# Authors: Collin Winter, Nick Edds
 
 # Local imports
 from .. import fixer_base
-from ..fixer_util import Name, attr_chain, any, set
+from ..fixer_util import Name, attr_chain
 
 MAPPING = {'StringIO':  'io',
            'cStringIO': 'io',
@@ -61,36 +61,49 @@ def alternates(members):
 
 
 def build_pattern(mapping=MAPPING):
-    mod_list = ' | '.join(["module='" + key + "'" for key in mapping.keys()])
-    mod_name_list = ' | '.join(["module_name='" + key + "'" for key in mapping.keys()])
-    yield """import_name< 'import' ((%s)
+    mod_list = ' | '.join(["module_name='%s'" % key for key in mapping])
+    bare_names = alternates(mapping.keys())
+
+    yield """name_import=import_name< 'import' ((%s)
                           | dotted_as_names< any* (%s) any* >) >
           """ % (mod_list, mod_list)
     yield """import_from< 'from' (%s) 'import' ['(']
               ( any | import_as_name< any 'as' any > |
                 import_as_names< any* >)  [')'] >
-          """ % mod_name_list
+          """ % mod_list
     yield """import_name< 'import'
                           dotted_as_name< (%s) 'as' any > >
-          """ % mod_name_list
-    # Find usages of module members in code e.g. urllib.foo(bar)
-    yield """power< (%s)
-             trailer<'.' any > any* >
-          """ % mod_name_list
-    yield """bare_name=%s""" % alternates(mapping.keys())
+          """ % mod_list
+
+    # Find usages of module members in code e.g. thread.foo(bar)
+    yield "power< bare_with_attr=(%s) trailer<'.' any > any* >" % bare_names
+
 
 class FixImports(fixer_base.BaseFix):
-    PATTERN = "|".join(build_pattern())
+
     order = "pre" # Pre-order tree traversal
 
+    # This is overridden in fix_imports2.
     mapping = MAPPING
 
-    # Don't match the node if it's within another match
+    def build_pattern(self):
+        return "|".join(build_pattern(self.mapping))
+
+    def compile_pattern(self):
+        # We override this, so MAPPING can be pragmatically altered and the
+        # changes will be reflected in PATTERN.
+        self.PATTERN = self.build_pattern()
+        super(FixImports, self).compile_pattern()
+
+    # Don't match the node if it's within another match.
     def match(self, node):
         match = super(FixImports, self).match
         results = match(node)
         if results:
-            if any([match(obj) for obj in attr_chain(node, "parent")]):
+            # Module usage could be in the trailier of an attribute lookup, so
+            # we might have nested matches when "bare_with_attr" is present.
+            if "bare_with_attr" not in results and \
+                    any([match(obj) for obj in attr_chain(node, "parent")]):
                 return False
             return results
         return False
@@ -100,20 +113,17 @@ class FixImports(fixer_base.BaseFix):
         self.replace = {}
 
     def transform(self, node, results):
-        import_mod = results.get("module")
-        mod_name = results.get("module_name")
-        bare_name = results.get("bare_name")
-
-        if import_mod or mod_name:
-            new_name = self.mapping[(import_mod or mod_name).value]
-
+        import_mod = results.get("module_name")
         if import_mod:
-            self.replace[import_mod.value] = new_name
+            new_name = self.mapping[(import_mod or mod_name).value]
+            if "name_import" in results:
+                # If it's not a "from x import x, y" or "import x as y" import,
+                # marked its usage to be replaced.
+                self.replace[import_mod.value] = new_name
             import_mod.replace(Name(new_name, prefix=import_mod.get_prefix()))
-        elif mod_name:
-            mod_name.replace(Name(new_name, prefix=mod_name.get_prefix()))
-        elif bare_name:
-            bare_name = bare_name[0]
+        else:
+            # Replace usage of the module.
+            bare_name = results["bare_with_attr"][0]
             new_name = self.replace.get(bare_name.value)
             if new_name:
                 bare_name.replace(Name(new_name, prefix=bare_name.get_prefix()))