gh-111506: Error if the limited API is used in free-threaded build (#117762)

Issue a build time error if both `Py_LIMITED_API` and `Py_GIL_DISABLED`
are defined.

diff --git a/Include/Python.h b/Include/Python.h
index ca38a98d8c4eca06f6090bc898bd06bac819c51f..bb771fb3aec980d2e6cc5550b601b41d6b576a77 100644 (file)
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -45,6 +45,11 @@
 #  endif
 #endif
 
+// gh-111506: The free-threaded build is not compatible with the limited API
+// or the stable ABI.
+#if defined(Py_LIMITED_API) && defined(Py_GIL_DISABLED)
+#  error "The limited API is not currently supported in the free-threaded build"
+#endif
 
 // Include Python header files
 #include "pyport.h"