Argument Clinic duplicate module check is malfunctioning

[erlend-aasland]

The following code is silently accepted by Argument Clinic:

/*[clinic input]
module m
module m
[clinic start generated code]*/

The duplicate module m should have been caught by Argument Clinic, but the guard is faulty:

cpython/Tools/clinic/clinic.py

Lines 4481 to 4482 in 9e6590b

	if name in module.classes:
	fail("Already defined module " + repr(name) + "!")

The check should be against .modules, not .classes:

diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 1bcdb6b1c3..dc4a7f9318 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -4478,7 +4478,7 @@ def directive_module(self, name: str) -> None:
         if cls:
             fail("Can't nest a module inside a class!")
 
-        if name in module.classes:
+        if name in module.modules:
             fail("Already defined module " + repr(name) + "!")
 
         m = Module(name, module)

See also the Module class:

cpython/Tools/clinic/clinic.py

Lines 2384 to 2392 in 9e6590b

	class Module:
	name: str
	module: Module | Clinic
	def __post_init__(self) -> None:
	self.parent = self.module
	self.modules: ModuleDict = {}
	self.classes: ClassDict = {}
	self.functions: list[Function] = []

Linked PRs

• gh-107609: Fix duplicate module check in Argument Clinic #107610
• [3.12] gh-107609: Fix duplicate module check in Argument Clinic (GH-107610) #107612

[erlend-aasland]

Discovered while expanding the test suite to cover all directives and commands.

[erlend-aasland]

Fixed in main by:

• gh-107609: Fix duplicate module check in Argument Clinic #107610