bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

[George O'Hara]

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Hi,

From 'emacs -Q', C-x C-f and create a buffer called 'test.c'.
In this buffer, type:

static int some_function();
int static another_function();

some_function is not highlighted, while another_function is.
I would expect both to be highlighted.
Note that this also happens with C++.


In GNU Emacs 26.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.30)
of 2020-05-13 built on gohara-t450s
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Linux Mint 19.3 Tricia

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list... [2 times]

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS LCMS2

Important settings:
value of $LANG: en_GB.UTF-8
locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
tooltip-mode: t
global-eldoc-mode: t
electric-indent-mode: t
mouse-wheel-mode: t
tool-bar-mode: t
menu-bar-mode: t
file-name-shadow-mode: t
global-font-lock-mode: t
blink-cursor-mode: t
auto-composition-mode: t
auto-encryption-mode: t
auto-compression-mode: t
buffer-read-only: t
line-number-mode: t
transient-mark-mode: t

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None found.

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Memory information:
((conses 16 97752 8020)
(symbols 48 20379 1)
(miscs 40 84 118)
(strings 32 28409 1537)
(string-bytes 1 746781)
(vectors 16 14596)
(vector-slots 8 505938 8384)
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bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

[Eli Zaretskii]

> From: "George O'Hara" <georgeohara92@gmail.com>
> Date: Fri, 15 May 2020 12:15:42 +0100
> 
> >From 'emacs -Q', C-x C-f and create a buffer called 'test.c'. 
> In this buffer, type: 
> 
> static int some_function(); 
> int static another_function(); 
> 
> some_function is not highlighted, while another_function is. 

You mean, the other way around, no?

bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

[George O'Hara]

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Hi Eli!

Yes, I do mean the other way round.
I made a post on the Emacs SE with images last night, which may be useful
to link here.
https://emacs.stackexchange.com/questions/58509/static-function-highlighting-locking-in-c?noredirect=1#comment91178_58509

As an aside, I accidentally posted this bug twice. Is there a way I can
close the other issue?

Kind regards

On Fri, 15 May 2020 at 12:57, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: "George O'Hara" <georgeohara92@gmail.com>
> > Date: Fri, 15 May 2020 12:15:42 +0100
> >
> > >From 'emacs -Q', C-x C-f and create a buffer called 'test.c'.
> > In this buffer, type:
> >
> > static int some_function();
> > int static another_function();
> >
> > some_function is not highlighted, while another_function is.
>
> You mean, the other way around, no?
>

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bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

[Alan Mackenzie]

Hello, George.

On Fri, May 15, 2020 at 13:03:39 +0100, George O'Hara wrote:
> Hi Eli!

> Yes, I do mean the other way round.
> I made a post on the Emacs SE with images last night, which may be useful
> to link here.
> https://emacs.stackexchange.com/questions/58509/static-function-highlighting-locking-in-c?noredirect=1#comment91178_58509

Could you please try out the following patch.  The file cc-langs.el is in
directory .../emacs/lisp/progmodes.  Because the change is in a macro,
you will need to rebuild all of cc-*.el to get a clean build.  (If you
want any help with the patching or byte compiling, feel free to send me
private email.)

The patch increases considerably the number of keywords which can come
after the "int", when previously they had to come before it.  Please let
us all know whether the patch actually fixes the bug satisfactorally.
Thanks!



diff -r de83a122cf12 cc-langs.el
--- a/cc-langs.el	Fri May 15 19:04:24 2020 +0000
+++ b/cc-langs.el	Sun May 17 19:12:39 2020 +0000
@@ -3402,8 +3402,14 @@
 The end of the first submatch is taken as the end of the operator.
 Identifier syntax is in effect when this is matched (see
 `c-identifier-syntax-table')."
-  t (if (c-lang-const c-type-modifier-kwds)
-	(concat (regexp-opt (c-lang-const c-type-modifier-kwds) t) "\\>")
+  t (if (or (c-lang-const c-type-modifier-kwds) (c-lang-const c-modifier-kwds))
+        (concat
+	 (regexp-opt (c--delete-duplicates
+		      (append (c-lang-const c-type-modifier-kwds)
+			      (c-lang-const c-modifier-kwds))
+		      :test 'string-equal)
+		     t)
+	 "\\>")
       ;; Default to a regexp that never matches.
       "\\`a\\`")
   ;; Check that there's no "=" afterwards to avoid matching tokens



> As an aside, I accidentally posted this bug twice. Is there a way I can
> close the other issue?

> Kind regards

> On Fri, 15 May 2020 at 12:57, Eli Zaretskii <eliz@gnu.org> wrote:

> > > From: "George O'Hara" <georgeohara92@gmail.com>
> > > Date: Fri, 15 May 2020 12:15:42 +0100

> > > >From 'emacs -Q', C-x C-f and create a buffer called 'test.c'.
> > > In this buffer, type:

> > > static int some_function();
> > > int static another_function();

> > > some_function is not highlighted, while another_function is.

> > You mean, the other way around, no?

-- 
Alan Mackenzie (Nuremberg, Germany).

bug#41284: 26.3; cc-mode: Incorrect font locking of static functions

[Alan Mackenzie]

Hello, George.

On Mon, May 18, 2020 at 09:52:26 +0100, George O'Hara wrote:
> Hi Alan,

> I can confirm that fixes it.
> A huge thank you for your help!

OK, that's great,thanks!  I've committed the patch to the master branch
at savannah, and I'm closing the bug with this post.

> Kind regards
> George

-- 
Alan Mackenzie (Nuremberg, Germany).