Prefer 'ARRAYELTS (x)' to 'sizeof x / sizeof *x'

* src/comp.c (emit_limple_insn):
* src/msdos.c (dos_set_keyboard, dos_rawgetc):
* src/sysdep.c (convert_speed, list_system_processes):
* src/w32fns.c (deliver_wm_chars, Fx_file_dialog):
* src/w32term.c (record_event, w32_read_socket):
Prefer 'ARRAYELTS (x)' to 'sizeof x / sizeof *x'.

* admin/coccinelle/arrayelts.cocci: New file.

admin/coccinelle/arrayelts.cocci

@@ -0,0 +1,21 @@
+// Use the ARRAYELTS macro where possible.
+@@
+type T;
+T[] E;
+@@
+- (sizeof (E) / sizeof (E[...]))
++ ARRAYELTS (E)
+
+@@
+type T;
+T[] E;
+@@
+- (sizeof (E) / sizeof (T))
++ ARRAYELTS (E)
+
+@@
+type T;
+T[] E;
+@@
+- (sizeof (E) / sizeof (*E))
++ ARRAYELTS (E)

src/comp.c

@@ -2279,7 +2279,7 @@ emit_limple_insn (Lisp_Object insn)
   ptrdiff_t i = 0;
   FOR_EACH_TAIL (p)
     {
-      if (i == sizeof (arg) / sizeof (Lisp_Object))
+      if (i == ARRAYELTS (arg))
 	break;
       arg[i++] = XCAR (p);
     }

src/msdos.c

@@ -2069,7 +2069,7 @@ dos_set_keyboard (int code, int always)
   keyboard_map_all = always;
   dos_keyboard_layout = 1;
 
-  for (i = 0; i < (sizeof (keyboard_layout_list)/sizeof (struct keyboard_layout_list)); i++)
+  for (i = 0; i < ARRAYELTS (keyboard_layout_list); i++)
     if (code == keyboard_layout_list[i].country_code)
       {
 	keyboard = keyboard_layout_list[i].keyboard_map;
@@ -2512,7 +2512,7 @@ dos_rawgetc (void)
              one.  */
 	  if (code == -1)
 	    {
-	      if (sc >= (sizeof (ibmpc_translate_map) / sizeof (short)))
+	      if (sc >= ARRAYELTS (ibmpc_translate_map))
 		continue;
 	      if ((code = ibmpc_translate_map[sc]) == Ignore)
 		continue;

src/sysdep.c

@@ -3160,7 +3160,7 @@ static const struct speed_struct speeds[] =
 static speed_t
 convert_speed (speed_t speed)
 {
-  for (size_t i = 0; i < sizeof speeds / sizeof speeds[0]; i++)
+  for (size_t i = 0; i < ARRAYELTS (speeds); i++)
     {
       if (speed == speeds[i].internal)
 	return speed;
@@ -3380,7 +3380,7 @@ list_system_processes (void)
   int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PROC};
 #endif
   size_t len;
-  size_t mibsize = sizeof mib / sizeof mib[0];
+  size_t mibsize = ARRAYELTS (mib);
   struct kinfo_proc *procs;
   size_t i;
 

src/w32fns.c

@@ -4154,7 +4154,7 @@ deliver_wm_chars (int do_translate, HWND hwnd, UINT msg, UINT wParam,
       windows_msg.time = GetMessageTime ();
       TranslateMessage (&windows_msg);
     }
-  count = get_wm_chars (hwnd, buf, sizeof (buf)/sizeof (*buf), 1,
+  count = get_wm_chars (hwnd, buf, ARRAYELTS (buf), 1,
 			/* The message may have been synthesized by
 			   who knows what; be conservative.  */
 			modifier_set (VK_LCONTROL)
@@ -8379,8 +8379,7 @@ DEFUN ("x-file-dialog", Fx_file_dialog, Sx_file_dialog, 2, 5, 0,
 	  file_details_w->lStructSize = sizeof (*file_details_w);
 	/* Set up the inout parameter for the selected file name.  */
 	file_details_w->lpstrFile = filename_buf_w;
-	file_details_w->nMaxFile =
-	  sizeof (filename_buf_w) / sizeof (*filename_buf_w);
+	file_details_w->nMaxFile = ARRAYELTS (filename_buf_w);
 	file_details_w->hwndOwner = FRAME_W32_WINDOW (f);
 	/* Undocumented Bug in Common File Dialog:
 	   If a filter is not specified, shell links are not resolved.  */
@@ -8413,8 +8412,7 @@ DEFUN ("x-file-dialog", Fx_file_dialog, Sx_file_dialog, 2, 5, 0,
 	else
 	  file_details_a->lStructSize = sizeof (*file_details_a);
 	file_details_a->lpstrFile = filename_buf_a;
-	file_details_a->nMaxFile =
-	  sizeof (filename_buf_a) / sizeof (*filename_buf_a);
+	file_details_a->nMaxFile = ARRAYELTS (filename_buf_a);
 	file_details_a->hwndOwner = FRAME_W32_WINDOW (f);
 	file_details_a->lpstrFilter = filter_a;
 	file_details_a->lpstrInitialDir = dir_a;

src/w32term.c

@@ -276,7 +276,7 @@ int event_record_index;
 
 record_event (char *locus, int type)
 {
-  if (event_record_index == sizeof (event_record) / sizeof (struct record))
+  if (event_record_index == ARRAYELTS (event_record))
     event_record_index = 0;
 
   event_record[event_record_index].locus = locus;
@@ -5259,7 +5259,7 @@ w32_read_socket (struct terminal *terminal,
 		  hlinfo->mouse_face_hidden = true;
 		}
 
-	      if (temp_index == sizeof temp_buffer / sizeof (short))
+	      if (temp_index == ARRAYELTS (temp_buffer))
 		temp_index = 0;
 	      temp_buffer[temp_index++] = msg.msg.wParam;
 	      inev.kind = NON_ASCII_KEYSTROKE_EVENT;
@@ -5285,7 +5285,7 @@ w32_read_socket (struct terminal *terminal,
 		  hlinfo->mouse_face_hidden = true;
 		}
 
-	      if (temp_index == sizeof temp_buffer / sizeof (short))
+	      if (temp_index == ARRAYELTS (temp_buffer))
 		temp_index = 0;
 	      temp_buffer[temp_index++] = msg.msg.wParam;
 
@@ -5400,7 +5400,7 @@ w32_read_socket (struct terminal *terminal,
 		  hlinfo->mouse_face_hidden = true;
 		}
 
-	      if (temp_index == sizeof temp_buffer / sizeof (short))
+	      if (temp_index == ARRAYELTS (temp_buffer))
 		temp_index = 0;
 	      temp_buffer[temp_index++] = msg.msg.wParam;
 	      inev.kind = MULTIMEDIA_KEY_EVENT;