add support for annotations on "*args" and "**kwargs" arguments

Cython/Compiler/ExprNodes.py

@@ -7812,6 +7812,14 @@ class PyCFunctionNode(ExprNode, ModuleNameMixin):
                 if not arg.annotation.type.is_pyobject:
                     arg.annotation = arg.annotation.coerce_to_pyobject(env)
                 annotations.append((arg.pos, arg.name, arg.annotation))
+
+        for arg in (self.def_node.star_arg, self.def_node.starstar_arg):
+            if arg and arg.annotation:
+                arg.annotation = arg.annotation.analyse_types(env)
+                if not arg.annotation.type.is_pyobject:
+                    arg.annotation = arg.annotation.coerce_to_pyobject(env)
+                annotations.append((arg.pos, arg.name, arg.annotation))
+
         if self.def_node.return_type_annotation:
             annotations.append((self.def_node.return_type_annotation.pos,
                                 StringEncoding.EncodedString("return"),

tests/run/cython3.pyx

-# cython: language_level=3
+# cython: language_level=3, binding=True
 # mode: run
 # tag: generators, python3, exceptions
 
@@ -437,11 +437,24 @@ def int_literals():
     print(cython.typeof(1UL))
     print(cython.typeof(10000000000000UL))
 
-def annotation_syntax(a : "test new test", b : "other" = 2) -> "ret":
+def annotation_syntax(a: "test new test", b : "other" = 2, *args: "ARGS", **kwargs: "KWARGS") -> "ret":
     """
     >>> annotation_syntax(1)
     3
     >>> annotation_syntax(1,3)
     4
+
+    >>> len(annotation_syntax.__annotations__)
+    5
+    >>> print(annotation_syntax.__annotations__['a'])
+    test new test
+    >>> print(annotation_syntax.__annotations__['b'])
+    other
+    >>> print(annotation_syntax.__annotations__['args'])
+    ARGS
+    >>> print(annotation_syntax.__annotations__['kwargs'])
+    KWARGS
+    >>> print(annotation_syntax.__annotations__['return'])
+    ret
     """
     return a+b