Prepare module header generation for Emacs 28.

* configure.ac: Substitute environment function snippet for Emacs 28.

* src/module-env-28.h: New file, with dummy contents for now.

* src/emacs-module.h.in: Provide emacs_env_28 structure.

2 files changed, 14 insertions, 0 deletions

diff --git a/src/emacs-module.h.in b/src/emacs-module.h.in
index f12eedbfbea..a4312730143 100644
--- a/src/emacs-module.h.in
+++ b/src/emacs-module.h.in
@@ -125,6 +125,17 @@ struct emacs_env_27
 @module_env_snippet_27@
 };
 
+struct emacs_env_28
+{
+@module_env_snippet_25@
+
+@module_env_snippet_26@
+
+@module_env_snippet_27@
+
+@module_env_snippet_28@
+};
+
 /* Every module should define a function as follows.  */
 extern int emacs_module_init (struct emacs_runtime *runtime)
   EMACS_NOEXCEPT
diff --git a/src/module-env-28.h b/src/module-env-28.h
new file mode 100644
index 00000000000..dec8704edde
--- /dev/null
+++ b/src/module-env-28.h
@@ -0,0 +1,3 @@
+  /* 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.  */