GNU bug report logs - #57075
CC Mode 5.35.1 (C/*l); Leaky fontification of xterm.c with font-lock-maximum-decoration set to 2

Previous Next

To reply to this bug, email your comments to 57075 AT debbugs.gnu.org.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Po Lu <luangruo <at> yahoo.com>
To: bug-gnu-emacs <at> gnu.org
Subject: CC Mode 5.35.1 (C/*l); Leaky fontification of xterm.c with
 font-lock-maximum-decoration set to 2
Date: Tue, 09 Aug 2022 20:31:32 +0800

Package: cc-mode

Open xterm.c with font-lock-maximum-decoration set to 2, and hold down
C-v until the entire buffer is fontified.  Then, go to line 2948:
observe that the following lines in the vicinity are not fontified at
all:

  Atom type;        <-----------------------------------
  Window *toplevels;<-----------------------------------
  int format, rc;
  unsigned long nitems, bytes_after;
  unsigned long i, real_nitems;
  unsigned char *data = NULL;
  int frame_extents[4];

#ifndef USE_XCB
  int dest_x, dest_y;
  unsigned long *wmstate;
  unsigned long wmstate_items, extent_items;
  unsigned char *wmstate_data = NULL, *extent_data = NULL;
  XWindowAttributes attrs;<-----------------------------
  Window child;           <-----------------------------
  xm_drag_receiver_info xm_info; <----------------------

Many other other lines in the buffer will also be missing fontification.


Emacs  : GNU Emacs 29.0.50 (build 62, x86_64-pc-linux-gnu)
 of 2022-08-09
Package: CC Mode 5.35.1 (C/*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)

current state:
==============
(setq
 c-basic-offset 2
 c-comment-only-line-offset '(0 . 0)
 c-indent-comment-alist '((anchored-comment column . 0) (end-block space . 1) (cpp-end-block space . 2))
 c-indent-comments-syntactically-p nil
 c-block-comment-prefix ""
 c-comment-prefix-regexp '((pike-mode . "//+!?\\|\\**") (awk-mode . "#+") (other . "//+\\|\\**"))
 c-doc-comment-style '((java-mode . javadoc) (pike-mode . autodoc) (c-mode . gtkdoc) (c++-mode . gtkdoc))
 c-cleanup-list '(scope-operator)
 c-hanging-braces-alist '((substatement-open before after) (arglist-cont-nonempty))
 c-hanging-colons-alist nil
 c-hanging-semi&comma-criteria '(c-semi&comma-inside-parenlist)
 c-backslash-column 48
 c-backslash-max-column 72
 c-special-indent-hook '(t c-gnu-impose-minimum)
 c-label-minimum-indentation 1
 c-offsets-alist '((inexpr-class . +)
		   (inexpr-statement . +)
		   (lambda-intro-cont . +)
		   (inlambda . 0)
		   (template-args-cont c-lineup-template-args +)
		   (incomposition . +)
		   (inmodule . +)
		   (innamespace . +)
		   (inextern-lang . +)
		   (composition-close . 0)
		   (module-close . 0)
		   (namespace-close . 0)
		   (extern-lang-close . 0)
		   (composition-open . 0)
		   (module-open . 0)
		   (namespace-open . 0)
		   (extern-lang-open . 0)
		   (objc-method-call-cont c-lineup-ObjC-method-call-colons c-lineup-ObjC-method-call +)
		   (objc-method-args-cont . c-lineup-ObjC-method-args)
		   (objc-method-intro . [0])
		   (friend . 0)
		   (cpp-define-intro c-lineup-cpp-define +)
		   (cpp-macro-cont . +)
		   (cpp-macro . [0])
		   (inclass . +)
		   (stream-op . c-lineup-streamop)
		   (arglist-cont-nonempty c-lineup-gcc-asm-reg c-lineup-arglist)
		   (arglist-cont c-lineup-gcc-asm-reg 0)
		   (comment-intro c-lineup-knr-region-comment c-lineup-comment)
		   (catch-clause . 0)
		   (else-clause . 0)
		   (do-while-closure . 0)
		   (access-label . -)
		   (case-label . 0)
		   (substatement . +)
		   (statement-case-intro . +)
		   (statement . 0)
		   (brace-entry-open . 0)
		   (brace-list-entry . 0)
		   (brace-list-close . 0)
		   (block-close . 0)
		   (block-open . 0)
		   (inher-cont . c-lineup-multi-inher)
		   (inher-intro . +)
		   (member-init-cont . c-lineup-multi-inher)
		   (member-init-intro . +)
		   (annotation-var-cont . +)
		   (annotation-top-cont . 0)
		   (topmost-intro . 0)
		   (knr-argdecl . 0)
		   (func-decl-cont . +)
		   (inline-close . 0)
		   (class-close . 0)
		   (class-open . 0)
		   (defun-block-intro . +)
		   (defun-close . 0)
		   (defun-open . 0)
		   (c . c-lineup-C-comments)
		   (string . c-lineup-dont-change)
		   (topmost-intro-cont first c-lineup-topmost-intro-cont c-lineup-gnu-DEFUN-intro-cont)
		   (brace-list-intro first c-lineup-2nd-brace-entry-in-arglist c-lineup-class-decl-init-+ +)
		   (brace-list-open . +)
		   (inline-open . 0)
		   (arglist-close . c-lineup-arglist)
		   (arglist-intro . c-lineup-arglist-intro-after-paren)
		   (statement-cont . +)
		   (statement-case-open . +)
		   (label . 0)
		   (substatement-label . 0)
		   (substatement-open . +)
		   (knr-argdecl-intro . 5)
		   (statement-block-intro . +)
		   )
 c-buffer-is-cc-mode 'c-mode
 c-tab-always-indent t
 c-syntactic-indentation t
 c-syntactic-indentation-in-macros t
 c-ignore-auto-fill '(string cpp code)
 c-auto-align-backslashes t
 c-backspace-function 'backward-delete-char-untabify
 c-delete-function 'delete-char
 c-electric-pound-behavior nil
 c-default-style '((java-mode . "java") (awk-mode . "awk") (other . "gnu"))
 c-enable-xemacs-performance-kludge-p nil
 c-old-style-variable-behavior nil
 defun-prompt-regexp nil
 tab-width 8
 comment-column 32
 parse-sexp-ignore-comments t
 parse-sexp-lookup-properties t
 auto-fill-function nil
 comment-multi-line t
 comment-start-skip "\\(?://+\\|/\\*+\\)\\s *"
 fill-prefix nil
 fill-column 70
 paragraph-start "[ 	]*\\(//+\\|\\**\\)[ 	]*$\\|^\f"
 adaptive-fill-mode t
 adaptive-fill-regexp "[ 	]*\\(//+\\|\\**\\)[ 	]*\\([ 	]*\\([-–!|#%;>*·•‣⁃◦]+[ 	]*\\)*\\)"
 )

Message #8 received at 57075 <at> debbugs.gnu.org (full text, mbox):

From: Alan Mackenzie <acm <at> muc.de>
To: Po Lu <luangruo <at> yahoo.com>
Cc: acm <at> muc.de, 57075 <at> debbugs.gnu.org
Subject: Re: bug#57075: CC Mode 5.35.1 (C/*l); Leaky fontification of xterm.c
 with font-lock-maximum-decoration set to 2
Date: Wed, 10 Aug 2022 18:51:30 +0000

Hello, Po.

On Tue, Aug 09, 2022 at 20:31:32 +0800, Po Lu via CC-Mode-help wrote:
> Package: cc-mode

> Open xterm.c with font-lock-maximum-decoration set to 2, and hold down
> C-v until the entire buffer is fontified.  Then, go to line 2948:
> observe that the following lines in the vicinity are not fontified at
> all:

>   Atom type;        <-----------------------------------
>   Window *toplevels;<-----------------------------------
>   int format, rc;
>   unsigned long nitems, bytes_after;
>   unsigned long i, real_nitems;
>   unsigned char *data = NULL;
>   int frame_extents[4];

> #ifndef USE_XCB
>   int dest_x, dest_y;
>   unsigned long *wmstate;
>   unsigned long wmstate_items, extent_items;
>   unsigned char *wmstate_data = NULL, *extent_data = NULL;
>   XWindowAttributes attrs;<-----------------------------
>   Window child;           <-----------------------------
>   xm_drag_receiver_info xm_info; <----------------------

> Many other other lines in the buffer will also be missing fontification.

Yes.  It's the way level 2 does fontification of types.  Any declaration
which starts with a standard type, like int, char, void, ..... gets
fontified, additionally anything like struct foo *bar, and any type
matching one of the following: 

    ("\\sw+_t" "bool" "complex" "imaginary" "FILE" "lconv" "tm" "va_list"
     "jmp_buf" "Lisp_Object")

..  So the types ending in _t, like xcb_translate_coordinates_cookie_t
are getting fontified too, but not things like Atom or Window *.

The merly partial fontification is the price for the extra speed one
gets from level 2.  To fontify all declarations, we'd need the
algorithms from f-l-maximum-decoration 3, and the speed would pretty
much be down to that of f-l-m-d 3, too.

Sorry nothing better is possible (at the moment).

> Emacs  : GNU Emacs 29.0.50 (build 62, x86_64-pc-linux-gnu)
>  of 2022-08-09
> Package: CC Mode 5.35.1 (C/*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)

[ CC Mode state dump appreciated, but snipped. ]

-- 
Alan Mackenzie (Nuremberg, Germany).

Message #11 received at 57075 <at> debbugs.gnu.org (full text, mbox):

From: Po Lu <luangruo <at> yahoo.com>
To: Alan Mackenzie <acm <at> muc.de>
Cc: 57075 <at> debbugs.gnu.org
Subject: Re: bug#57075: CC Mode 5.35.1 (C/*l); Leaky fontification of
 xterm.c with font-lock-maximum-decoration set to 2
Date: Thu, 11 Aug 2022 09:44:05 +0800

Alan Mackenzie <acm <at> muc.de> writes:

> Yes.  It's the way level 2 does fontification of types.  Any declaration
> which starts with a standard type, like int, char, void, ..... gets
> fontified, additionally anything like struct foo *bar, and any type
> matching one of the following: 
>
>     ("\\sw+_t" "bool" "complex" "imaginary" "FILE" "lconv" "tm" "va_list"
>      "jmp_buf" "Lisp_Object")
>
> ..  So the types ending in _t, like xcb_translate_coordinates_cookie_t
> are getting fontified too, but not things like Atom or Window *.
>
> The merly partial fontification is the price for the extra speed one
> gets from level 2.  To fontify all declarations, we'd need the
> algorithms from f-l-maximum-decoration 3, and the speed would pretty
> much be down to that of f-l-m-d 3, too.
>
> Sorry nothing better is possible (at the moment).

Okay, thanks for explaining.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.