bug#59234: CC Mode 5.35.2 (ObjC//l); Random fontification of nsterm.m

Alan Mackenzie <[email protected]> writes:

> Hello, Po.
>
> On Sun, Nov 13, 2022 at 11:13:02 +0800, Po Lu via CC-Mode-help wrote:
>> Package: cc-mode
>
>> If you go to src/nsterm.m, around line 4020 there should be the
>> following code:
>
>> static void
>> ns_draw_stretch_glyph_string (struct glyph_string *s)
>> {
>>   struct face *face;
>>   NSColor *fg_color;
>
>>   if (s->hl == DRAW_CURSOR
>>       && !x_stretch_cursor_p)
>>     {
>>       /* If `x-stretch-cursor' is nil, don't draw a block cursor as
>> 	 wide as the stretch glyph.  */
>>       int width, background_width = s->background_width;
>>       int x = s->x;
>
>>       if (!s->row->reversed_p)
>> 	{
>> 	  int left_x = window_box_left_offset (s->w, TEXT_AREA);
>
>> 	  if (x < left_x)
>> 	    {
>> 	      background_width -= left_x - x;
>> 	      x = left_x;
>> 	    }
>> 	}
>>       else
>> 	{
>
>> in it, "width" and "background_width" are seemingly randomly fontified
>> as types.  Then, if you scroll up to line 3658, you will see the
>> following code:
>
>
>>       if (left_p && top_p)
>> 	[NSBezierPath fillRect: NSMakeRect (NSMinX (outer),
>> 					    NSMinY (outer),
>> 					    1, 1)];
>
>>       if (right_p && top_p)
>> 	[NSBezierPath fillRect: NSMakeRect (NSMaxX (outer) - 1,
>> 					    NSMinY (outer),
>> 					    1, 1)];
>
>>       if (right_p && bottom_p)
>> 	[NSBezierPath fillRect: NSMakeRect (NSMaxX (outer) - 1,
>> 					    NSMaxY (outer) - 1,
>> 					    1, 1)];
>
>>       if (left_p && bottom_p)
>> 	[NSBezierPath fillRect: NSMakeRect (NSMinX (outer),
>> 					    NSMaxY (outer) - 1,
>> 					    1, 1)];
>
>> NSBezierPath is a type, and is correctly fontified, but NSMinX and
>> NSMaxX (and their Y variants) are functions, yet are fontified as types.
>
> The problem here is the setting of the customisable variable
> objc-font-lock-extra-types.  In Objective C's case, it causes all
> identifiers beginning with an upper case letter and containing a lower
> case letter to be recognised as types.
>
> This is clearly not satisfactory, even if it was OK a long time ago.
>
> I would recommend you to customize this variable to nil.  Note that CC
> Mode internal stuff gets set up at an early stage of Objective C Mode's
> initialisation, before buffer local variables or .dir-local.el get
> processed.  So trying to change it in these places won't work (believe
> me, I've tried ;-).
>
> I'll try and think up a more satisfactory solution.
>
>> Thanks.
>
>> Emacs  : GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu)
>>  of 2022-11-12
>> Package: CC Mode 5.35.2 (ObjC//l)
>> Buffer Style: GNU
>> c-emacs-features: (pps-extended-state col-0-paren posix-char-classes gen-string-delim gen-comment-delim syntax-properties category-properties 1-bit)
>
> [ .... ]

Thank you.