gh-106359: Fix corner case bugs in Argument Clinic converter parser (#106361)

DSLParser.parse_converter() could return unusable kwdicts in some rare cases

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

diff --git a/Lib/test/test_clinic.py b/Lib/test/test_clinic.py
index a6ce9c2570cb62557d11ec948191afe60d88fca7..fab2d2bb0bdbe4ef946e530b7982afa454558a54 100644 (file)
--- a/Lib/test/test_clinic.py
+++ b/Lib/test/test_clinic.py
@@ -813,6 +813,22 @@ Annotations must be either a name, a function call, or a string.
         )
         self.assertEqual(s, expected_failure_message)
 
+    def test_kwarg_splats_disallowed_in_function_call_annotations(self):
+        expected_error_msg = (
+            "Error on line 0:\n"
+            "Cannot use a kwarg splat in a function-call annotation\n"
+        )
+        dataset = (
+            'module fo\nfo.barbaz\n   o: bool(**{None: "bang!"})',
+            'module fo\nfo.barbaz -> bool(**{None: "bang!"})',
+            'module fo\nfo.barbaz -> bool(**{"bang": 42})',
+            'module fo\nfo.barbaz\n   o: bool(**{"bang": None})',
+        )
+        for fn in dataset:
+            with self.subTest(fn=fn):
+                out = self.parse_function_should_fail(fn)
+                self.assertEqual(out, expected_error_msg)
+
     def test_unused_param(self):
         block = self.parse("""
             module foo

diff --git a/Misc/NEWS.d/next/Tools-Demos/2023-07-03-14-06-19.gh-issue-106359.RfJuR0.rst b/Misc/NEWS.d/next/Tools-Demos/2023-07-03-14-06-19.gh-issue-106359.RfJuR0.rst
new file mode 100644 (file)
index 0000000..600c265
--- /dev/null
+++ b/Misc/NEWS.d/next/Tools-Demos/2023-07-03-14-06-19.gh-issue-106359.RfJuR0.rst
@@ -0,0 +1,2 @@
+Argument Clinic now explicitly forbids "kwarg splats" in function calls used as
+annotations.

diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 2e46131d4e336a882b47a5e50364e06bb221d337..47038f98aabd758f6468df6ba966164b311622fc 100755 (executable)
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -4291,6 +4291,7 @@ class IndentStack:
 
 
 StateKeeper = Callable[[str | None], None]
+ConverterArgs = dict[str, Any]
 
 class DSLParser:
     function: Function | None
@@ -5033,10 +5034,10 @@ class DSLParser:
         key = f"{parameter_name}_as_{c_name}" if c_name else parameter_name
         self.function.parameters[key] = p
 
-    KwargDict = dict[str | None, Any]
-
     @staticmethod
-    def parse_converter(annotation: ast.expr | None) -> tuple[str, bool, KwargDict]:
+    def parse_converter(
+            annotation: ast.expr | None
+    ) -> tuple[str, bool, ConverterArgs]:
         match annotation:
             case ast.Constant(value=str() as value):
                 return value, True, {}
@@ -5044,10 +5045,11 @@ class DSLParser:
                 return name, False, {}
             case ast.Call(func=ast.Name(name)):
                 symbols = globals()
-                kwargs = {
-                    node.arg: eval_ast_expr(node.value, symbols)
-                    for node in annotation.keywords
-                }
+                kwargs: ConverterArgs = {}
+                for node in annotation.keywords:
+                    if not isinstance(node.arg, str):
+                        fail("Cannot use a kwarg splat in a function-call annotation")
+                    kwargs[node.arg] = eval_ast_expr(node.value, symbols)
                 return name, False, kwargs
             case _:
                 fail(