pythongh-119180: Rename parameter to __annotate__ functions

Larry Hastings pointed out that using an illegal parameter name makes it impossible to use inspect.signature() on annotate functions. Cross-ref python/peps#3993.
JelleZijlstra · Sep 24, 2024 · f768678 · f768678
1 parent 17b3bc9
commit f768678
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Showing 7 changed files with 15 additions and 12 deletions.
diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h
diff --git a/Include/internal/pycore_global_strings.h b/Include/internal/pycore_global_strings.h
@@ -43,7 +43,6 @@ struct _Py_global_strings {
         STRUCT_FOR_STR(defaults, ".defaults")
         STRUCT_FOR_STR(dot_locals, ".<locals>")
         STRUCT_FOR_STR(empty, "")
-        STRUCT_FOR_STR(format, ".format")
         STRUCT_FOR_STR(generic_base, ".generic_base")
         STRUCT_FOR_STR(json_decoder, "json.decoder")
         STRUCT_FOR_STR(kwdefaults, ".kwdefaults")

diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h
diff --git a/Include/internal/pycore_unicodeobject_generated.h b/Include/internal/pycore_unicodeobject_generated.h
diff --git a/Lib/test/test_type_annotations.py b/Lib/test/test_type_annotations.py
@@ -1,4 +1,5 @@
 import annotationlib
+import inspect
 import textwrap
 import types
 import unittest
@@ -266,6 +267,17 @@ def check_annotations(self, f):
         f.__annotations__ = {"z": 43}
         self.assertIs(f.__annotate__, None)
 
+    def test_annotate_function_signature(self):
+        def f(x: int): pass
+        anno = f.__annotate__
+        self.assertIsInstance(anno, types.FunctionType)
+        self.assertEqual(f.__name__, "__annotate__")
+
+        expected_sig = inspect.Signature(
+            [inspect.Parameter("__format__", inspect.Parameter.POSITIONAL_ONLY)]
+        )
+        self.assertEqual(inspect.signature(anno), expected_sig)
+
 
 class DeferredEvaluationTests(unittest.TestCase):
     def test_function(self):

diff --git a/Python/codegen.c b/Python/codegen.c
@@ -655,8 +655,7 @@ codegen_setup_annotations_scope(compiler *c, location loc,
         codegen_enter_scope(c, name, COMPILE_SCOPE_ANNOTATIONS,
                             key, loc.lineno, NULL, &umd));
 
-    // if .format != 1: raise NotImplementedError
-    _Py_DECLARE_STR(format, ".format");
+    // if __format__ != 1: raise NotImplementedError
     ADDOP_I(c, loc, LOAD_FAST, 0);
     ADDOP_LOAD_CONST(c, loc, _PyLong_GetOne());
     ADDOP_I(c, loc, COMPARE_OP, (Py_NE << 5) | compare_masks[Py_NE]);

diff --git a/Python/symtable.c b/Python/symtable.c
@@ -1427,12 +1427,11 @@ symtable_enter_block(struct symtable *st, identifier name, _Py_block_ty block,
     int result = symtable_enter_existing_block(st, ste);
     Py_DECREF(ste);
     if (block == AnnotationBlock || block == TypeVariableBlock || block == TypeAliasBlock) {
-        _Py_DECLARE_STR(format, ".format");
         // We need to insert code that reads this "parameter" to the function.
-        if (!symtable_add_def(st, &_Py_STR(format), DEF_PARAM, loc)) {
+        if (!symtable_add_def(st, &_Py_ID(__format__), DEF_PARAM, loc)) {
             return 0;
         }
-        if (!symtable_add_def(st, &_Py_STR(format), USE, loc)) {
+        if (!symtable_add_def(st, &_Py_ID(__format__), USE, loc)) {
             return 0;
         }
     }