1 files changed, 23 insertions, 24 deletions
diff --git a/pre_commit/clientlib.py b/pre_commit/clientlib.py
index 6377a8b..47ebd54 100644
--- a/pre_commit/clientlib.py
+++ b/pre_commit/clientlib.py
@@ -144,18 +144,13 @@ class OptionalSensibleRegexAtHook(cfgv.OptionalNoDefault):
                 f"regex, not a glob -- matching '/*' probably isn't what you "
                 f'want here',
             )
-        if r'[\/]' in dct.get(self.key, ''):
-            logger.warning(
-                fr'pre-commit normalizes slashes in the {self.key!r} field '
-                fr'in hook {dct.get("id")!r} to forward slashes, so you '
-                fr'can use / instead of [\/]',
-            )
-        if r'[/\\]' in dct.get(self.key, ''):
-            logger.warning(
-                fr'pre-commit normalizes slashes in the {self.key!r} field '
-                fr'in hook {dct.get("id")!r} to forward slashes, so you '
-                fr'can use / instead of [/\\]',
-            )
+        for fwd_slash_re in (r'[\\/]', r'[\/]', r'[/\\]'):
+            if fwd_slash_re in dct.get(self.key, ''):
+                logger.warning(
+                    fr'pre-commit normalizes slashes in the {self.key!r} '
+                    fr'field in hook {dct.get("id")!r} to forward slashes, '
+                    fr'so you can use / instead of {fwd_slash_re}',
+                )
 
 
 class OptionalSensibleRegexAtTop(cfgv.OptionalNoDefault):
@@ -167,18 +162,13 @@ class OptionalSensibleRegexAtTop(cfgv.OptionalNoDefault):
                 f'The top-level {self.key!r} field is a regex, not a glob -- '
                 f"matching '/*' probably isn't what you want here",
             )
-        if r'[\/]' in dct.get(self.key, ''):
-            logger.warning(
-                fr'pre-commit normalizes the slashes in the top-level '
-                fr'{self.key!r} field to forward slashes, so you can use / '
-                fr'instead of [\/]',
-            )
-        if r'[/\\]' in dct.get(self.key, ''):
-            logger.warning(
-                fr'pre-commit normalizes the slashes in the top-level '
-                fr'{self.key!r} field to forward slashes, so you can use / '
-                fr'instead of [/\\]',
-            )
+        for fwd_slash_re in (r'[\\/]', r'[\/]', r'[/\\]'):
+            if fwd_slash_re in dct.get(self.key, ''):
+                logger.warning(
+                    fr'pre-commit normalizes the slashes in the top-level '
+                    fr'{self.key!r} field to forward slashes, so you '
+                    fr'can use / instead of {fwd_slash_re}',
+                )
 
 
 class MigrateShaToRev:
@@ -261,12 +251,21 @@ _meta = (
     ),
 )
 
+
+class NotAllowed(cfgv.OptionalNoDefault):
+    def check(self, dct: Dict[str, Any]) -> None:
+        if self.key in dct:
+            raise cfgv.ValidationError(f'{self.key!r} cannot be overridden')
+
+
 META_HOOK_DICT = cfgv.Map(
     'Hook', 'id',
     cfgv.Required('id', cfgv.check_string),
     cfgv.Required('id', cfgv.check_one_of(tuple(k for k, _ in _meta))),
     # language must be system
     cfgv.Optional('language', cfgv.check_one_of({'system'}), 'system'),
+    # entry cannot be overridden
+    NotAllowed('entry', cfgv.check_any),
     *(
         # default to the hook definition for the meta hooks
         cfgv.ConditionalOptional(key, cfgv.check_any, value, 'id', hook_id)