Pacify -Wcast-function-type warnings in GCC 8.1

* src/image.c: Move attributes into DEF_DLL_FN call.
* src/dynlib.c (dynlib_addr): Use get_proc_addr.
* src/w32.h: (get_proc_addr): New function.
(LOAD_DLL_FN): Use it.
(DEF_DLL_FN): Allow function attributes after argument
list.  Add function pointer type used by LOAD_DLL_FN.
* src/w32.c (open_process_token, get_token_information)
(lookup_account_sid, get_sid_sub_authority)
(get_sid_sub_authority_count, get_security_info)
(get_file_security, set_file_security)
(set_named_security_info)
(get_security_descriptor_owner, get_security_descriptor_group)
(get_security_descriptor_dacl, is_valid_sid, equal_sid)
(get_length_sid, copy_sid, get_native_system_info)
(get_system_times, create_symbolic_link)
(is_valid_security_descriptor, convert_sd_to_sddl)
(convert_sddl_to_sd, get_adapters_info, reg_open_key_ex_w)
(reg_query_value_ex_w, expand_environment_strings_w)
(init_environment, create_toolhelp32_snapshot)
(process32_first, process32_next, open_thread_token)
(impersonate_self, revert_to_self, get_process_memory_info)
(get_process_working_set_size, global_memory_status)
(global_memory_status_ex, init_winsock)
(maybe_load_unicows_dll, globals_of_w32): Use get_proc_addr.
* src/w32fns.c (setup_w32_kbdhook, Ffile_system_info)
(get_dll_version, w32_reset_stack_overflow_guard)
(w32_backtrace, globals_of_w32fns): Use get_proc_addr.
* src/w32font.c (get_outline_metrics_w, get_text_metrics_w)
(get_glyph_outline_w, get_char_width_32_w): Use get_proc_addr.
* src/w32heap.c (init_heap): Use get_proc_addr.
* src/w32menu.c (globals_of_w32menu): Use get_proc_addr.
* src/w32proc.c (init_timers, sys_kill, w32_compare_strings):
Use get_proc_addr.
* src/w32uniscribe.c (syms_of_w32uniscribe): Use get_proc_addr.

1 files changed, 23 insertions, 3 deletions

diff --git a/src/w32.h b/src/w32.h
index fe8689a07b4..a053ee0fc4b 100644
--- a/src/w32.h
+++ b/src/w32.h
@@ -164,6 +164,10 @@ extern void reset_standard_handles (int in, int out,
 /* Return the string resource associated with KEY of type TYPE.  */
 extern LPBYTE w32_get_resource (const char * key, LPDWORD type);
 
+/* Load a function from a DLL.  Defined in this file.  */
+typedef void (* VOIDFNPTR) (void);
+INLINE VOIDFNPTR get_proc_addr (HINSTANCE handle, LPCSTR fname);
+
 extern void release_listen_threads (void);
 extern void init_ntproc (int);
 extern void term_ntproc (int);
@@ -241,14 +245,30 @@ extern ssize_t emacs_gnutls_push (gnutls_transport_ptr_t p,
                                   const void* buf, size_t sz);
 #endif /* HAVE_GNUTLS */
 
-/* Definine a function that will be loaded from a DLL.  */
-#define DEF_DLL_FN(type, func, args) static type (FAR CDECL *fn_##func) args
+
+
+/* Load a function address from a DLL. Cast the result via "VOIDFNPTR"
+   to pacify -Wcast-function-type in GCC 8.1.  */
+INLINE VOIDFNPTR
+get_proc_addr (HINSTANCE handle, LPCSTR fname)
+{
+  return (VOIDFNPTR) GetProcAddress (handle, fname);
+}
+
+/* Define a function that will be loaded from a DLL.  The variable
+   arguments should contain the argument list for the function, and
+   optionally be followed by function attributes.  For example:
+   DEF_DLL_FN (void, png_longjmp, (png_structp, int) PNG_NORETURN);
+  */
+#define DEF_DLL_FN(type, func, ...)                     \
+  typedef type (CDECL *W32_PFN_##func) __VA_ARGS__;     \
+  static W32_PFN_##func fn_##func
 
 /* Load a function from the DLL.  */
 #define LOAD_DLL_FN(lib, func)						\
   do									\
     {									\
-      fn_##func = (void *) GetProcAddress (lib, #func);			\
+      fn_##func = (W32_PFN_##func) get_proc_addr (lib, #func);   \
       if (!fn_##func)							\
 	return false;							\
     }									\