Subject: bug#59953: 28.2; c type modifiers only work as prefixes for font-lock, cc-mode

From: Alan Mackenzie <[email-masked]>
Date: Sat, 14 Oct 2023 15:52:34 +0000

Hello, Chris.

Thanks for taking the trouble to file this bug, but sorry it's been such
a long time without a response.

I've now looked at the bug and it wasn't that difficult to patch.  If you
don't mind too much, I'll put your test file into the CC Mode test suite,
having added one line ("long int unsigned Three;") to it.

Would you please now apply the attached patch to your current Emacs (the
file cc-engine.el is in lisp/progmodes), byte compile cc-engine.el (or
just the whole of CC Mode), load the result into your Emacs and try it
out on your real source code.  Then please confirm to me that the bug is
fixed, or tell me what's still not right.  Thanks!  (If you want any help
in the patching of byte compilation, feel free to send me private email.)

On Sat, Dec 10, 2022 at 22:31:18 +0000, Chris Hecker wrote:
>    cc-mode doesn't seem to recognize that c type specifiers can come in
>    any order (and I prefer them after so they're modifying the base type),
>    so the highlighting doesn't work right for the variable name.Â  Here's
>    an example in a struct, works the same way in a function:

>    struct foo {
>      unsigned int One;
>     int unsigned Two;
>    };

>    emacs -Q results:

>    I couldn't see an easy way of fixing this (besides just adding all the
>    combos to *-font-lock-extra-types).Â  Seems like there needs to be a
>    c-primitive-type-postfix-kwds variable to do this right?

>    Thanks,

>    Chris

>    In GNU Emacs 28.2 (build 2, x86_64-w64-mingw32)
>    Â of 2022-09-13 built on AVALON

>    Windowing system distributor 'Microsoft Corp.', version 10.0.19044
>    System Description: Microsoft Windows 10 Home (v10.0.2009.19044.2251)
>    Configured using:
>    Â 'configure --with-modules --without-dbus --with-native-compilation
>    Â --without-compress-install CFLAGS=-O2'
>    Configured features:

[ .... ]

-- 
Alan Mackenzie (Nuremberg, Germany).

diff -r 97876aef276f cc-engine.el
--- a/cc-engine.el	Fri Oct 13 14:13:43 2023 +0000
+++ b/cc-engine.el	Sat Oct 14 15:51:43 2023 +0000
@@ -9461,37 +9461,47 @@
 		 (or c-promote-possible-types (eq res t)))
 	(c-record-type-id (cons (match-beginning 1) (match-end 1))))
 
-      (if (and c-opt-type-component-key
+      (cond
+       ((and c-opt-type-component-key
 	       (save-match-data
 		 (looking-at c-opt-type-component-key)))
 	  ;; There might be more keywords for the type.
-	  (let (safe-pos)
-	    (c-forward-keyword-clause 1 t)
-	    (while (progn
-		     (setq safe-pos (point))
-		     (c-forward-syntactic-ws)
-		     (looking-at c-opt-type-component-key))
-	      (when (and c-record-type-identifiers
-			 (looking-at c-primitive-type-key))
-		(c-record-type-id (cons (match-beginning 1)
-					(match-end 1))))
-	      (c-forward-keyword-clause 1 t))
-	    (if (looking-at c-primitive-type-key)
-		(progn
-		  (when c-record-type-identifiers
-		    (c-record-type-id (cons (match-beginning 1)
-					    (match-end 1))))
-		  (c-forward-keyword-clause 1 t)
-		  (setq res t))
-	      (goto-char safe-pos)
-	      (setq res 'prefix))
-	    (setq pos (point)))
-	(if (save-match-data (c-forward-keyword-clause 1 t))
-	    (setq pos (point))
-	  (if pos
-	      (goto-char pos)
-	    (goto-char (match-end 1))
-	    (setq pos (point)))))
+	(let (safe-pos)
+	  (c-forward-keyword-clause 1 t)
+	  (while (progn
+		   (setq safe-pos (point))
+		   (c-forward-syntactic-ws)
+		   (looking-at c-opt-type-component-key))
+	    (when (and c-record-type-identifiers
+		       (looking-at c-primitive-type-key))
+	      (c-record-type-id (cons (match-beginning 1)
+				      (match-end 1))))
+	    (c-forward-keyword-clause 1 t))
+	  (if (looking-at c-primitive-type-key)
+	      (progn
+		(when c-record-type-identifiers
+		  (c-record-type-id (cons (match-beginning 1)
+					  (match-end 1))))
+		(c-forward-keyword-clause 1 t)
+		(setq res t)
+		(while (progn
+			 (setq safe-pos (point))
+			 (c-forward-syntactic-ws)
+			 (looking-at c-opt-type-component-key))
+		  (c-forward-keyword-clause 1 t)))
+	    (goto-char safe-pos)
+	    (setq res 'prefix))
+	  (setq pos (point))))
+	((save-match-data (c-forward-keyword-clause 1 t))
+	 (while (progn
+		  (setq pos (point))
+		  (c-forward-syntactic-ws)
+		  (and c-opt-type-component-key
+		       (looking-at c-opt-type-component-key)))
+	   (c-forward-keyword-clause 1 t)))
+	(pos (goto-char pos))
+	(t (goto-char (match-end 1))
+	   (setq pos (point))))
       (c-forward-syntactic-ws))
 
      ((and (eq name-res t)