Implement finalizers for module functions (Bug#30373)

* src/module-env-28.h: Add new module environment functions to
module environment for Emacs 28.

* src/emacs-module.h.in: Document that 'emacs_finalizer' also works
for function finalizers.

* src/emacs-module.c (CHECK_MODULE_FUNCTION): New function.
(struct Lisp_Module_Function): Add finalizer data member.
(module_make_function): Initialize finalizer.
(module_get_function_finalizer)
(module_set_function_finalizer): New module environment functions.
(module_finalize_function): New function.
(initialize_environment): Initialize new environment functions.

* src/alloc.c (cleanup_vector): Call potential module function
finalizer during garbage collection.

* test/data/emacs-module/mod-test.c (signal_error): New helper
function.
(memory_full): Use it.
(finalizer): New example function finalizer.
(Fmod_test_make_function_with_finalizer)
(Fmod_test_function_finalizer_calls): New test module functions.
(emacs_module_init): Define them.

* test/src/emacs-module-tests.el (module/function-finalizer): New unit
test.

* doc/lispref/internals.texi (Module Functions): Document new
functionality.
(Module Misc): Move description of 'emacs_finalizer' type to 'Module
Functions' node, and add a reference to it.

* etc/NEWS: Mention new functionality.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/module-env-28.h b/src/module-env-28.h
index dec8704edde..a2479a8f744 100644
--- a/src/module-env-28.h
+++ b/src/module-env-28.h
@@ -1,3 +1,11 @@
   /* Add module environment functions newly added in Emacs 28 here.
      Before Emacs 28 is released, remove this comment and start
      module-env-29.h on the master branch.  */
+
+  void (*(*EMACS_ATTRIBUTE_NONNULL (1)
+            get_function_finalizer) (emacs_env *env,
+                                     emacs_value arg)) (void *) EMACS_NOEXCEPT;
+
+  void (*set_function_finalizer) (emacs_env *env, emacs_value arg,
+                                  void (*fin) (void *) EMACS_NOEXCEPT)
+    EMACS_ATTRIBUTE_NONNULL (1);