Port better to FreeBSD’s dlfunc vs dlsym

This avoids warnings when converting between void * and
function pointers, which strict C11 does not allow.
* configure.ac (dlfunc): Check for existence.
* src/dynlib.c (dlfunc) [!HAVE_DLFUNC]: New macro.
(dynlib_func): New function.
* src/dynlib.h (dynlib_function_ptr, dynlib_func): New decls.
* src/emacs-module.c (Fmodule_load): Use dynlib_func, not
dynlib_sym, for function pointers.

3 files changed, 15 insertions, 2 deletions

diff --git a/src/dynlib.c b/src/dynlib.c
index 47ffb418140..a41bed847bb 100644
--- a/src/dynlib.c
+++ b/src/dynlib.c
@@ -206,3 +206,13 @@ dynlib_close (dynlib_handle_ptr h)
 #error "No dynamic loading for this system"
 
 #endif
+
+#if !HAVE_DLFUNC
+# define dlfunc dynlib_sym
+#endif
+
+dynlib_function_ptr
+dynlib_func (dynlib_handle_ptr h, const char *sym)
+{
+  return (dynlib_function_ptr) dlfunc (h, sym);
+}
diff --git a/src/dynlib.h b/src/dynlib.h
index 1282c4fd719..1c19b5db8ac 100644
--- a/src/dynlib.h
+++ b/src/dynlib.h
@@ -25,6 +25,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 typedef void *dynlib_handle_ptr;
 dynlib_handle_ptr dynlib_open (const char *path);
 void *dynlib_sym (dynlib_handle_ptr h, const char *sym);
+typedef struct dynlib_function_ptr_nonce *(*dynlib_function_ptr) (void);
+dynlib_function_ptr dynlib_func (dynlib_handle_ptr h, const char *sym);
 bool dynlib_addr (void *ptr, const char **path, const char **sym);
 const char *dynlib_error (void);
 int dynlib_close (dynlib_handle_ptr h);
diff --git a/src/emacs-module.c b/src/emacs-module.c
index 1a5e253c969..209f99baf0f 100644
--- a/src/emacs-module.c
+++ b/src/emacs-module.c
@@ -710,7 +710,7 @@ DEFUN ("module-load", Fmodule_load, Smodule_load, 1, 1, 0,
   if (!gpl_sym)
     error ("Module %s is not GPL compatible", SDATA (file));
 
-  module_init = (emacs_init_function) dynlib_sym (handle, "emacs_module_init");
+  module_init = (emacs_init_function) dynlib_func (handle, "emacs_module_init");
   if (!module_init)
     error ("Module %s does not have an init function.", SDATA (file));
 
@@ -937,7 +937,8 @@ allocate_emacs_value (emacs_env *env, struct emacs_value_storage *storage,
 
 /* Mark all objects allocated from local environments so that they
    don't get garbage-collected.  */
-void mark_modules (void)
+void
+mark_modules (void)
 {
   for (Lisp_Object tem = Vmodule_environments; CONSP (tem); tem = XCDR (tem))
     {