Subject: Re: bug#59234: CC Mode 5.35.2 (ObjC//l); Random fontification of nsterm.m
From: Alan Mackenzie <[email-masked]>
To: Po Lu <[email-masked]>
Cc: [email-masked], [email-masked]
Date: Mon, 23 Jan 2023 21:34:51 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

Hello, Po.

On Mon, Nov 14, 2022 at 08:20:45 +0800, Po Lu wrote:
> Alan Mackenzie <[email-masked]> 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.

I've set the default value of objc-font-lock-extra-types to nil, and
committed the fix to the release branch.  I'm closing the bug with this
post.

-- 
Alan Mackenzie (Nuremberg, Germany).