master 36d9b8ce84a: CC Mode: Add second anchor point to class-open and class-close

[Alan Mackenzie]

branch: master
commit 36d9b8ce84afc8aaae3ce067fd24e172c0f631cf
Author: Alan Mackenzie <acm@muc.de>
Commit: Alan Mackenzie <acm@muc.de>

    CC Mode: Add second anchor point to class-open and class-close
    
    This fixes the second (last) part of bug#66911.  The new second
    anchor points allow the indentation of braces in template
    classes to be anchored on the keyword 'class' rather than the
    `template' at the beginning of the statement.
    
    * lisp/progmodes/cc-engine.el (c-add-class-syntax): Add &rest
    args parameter for additional anchor points.  Pass these to
    c-add-syntax.
    (c-guess-continued-construct): CASE B.1: Note return value from
    c-looking-at-decl-block and pass this to c-add-syntax for a
    class-open construct.
    (c-guess-basic-syntax): CASE 4: Duplicate anchor position for
    class-open.
    (c-guess-basic-syntax): CASE 5A.2: Note return value of
    c-looking-at-decl-block and pass it as extra argument to
    c-add-syntax for a class-open construct.
    (c-guess-basic-syntax): CASE 5G: Call c-looking-at-decl-block
    to determine the second anchor point for a class-close, and
    pass it to c-add-class-syntax.
    
    * doc/misc/cc-mode.texi (Class Symbols): Document the anchor
    points for class-open and class-close.
---
 doc/misc/cc-mode.texi       |  7 +++++++
 lisp/progmodes/cc-engine.el | 28 +++++++++++++++++++---------
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/doc/misc/cc-mode.texi b/doc/misc/cc-mode.texi
index 4ab95798468..8bc19235516 100644
--- a/doc/misc/cc-mode.texi
+++ b/doc/misc/cc-mode.texi
@@ -4507,6 +4507,13 @@ languages are syntactically equivalent to classes.  Note 
however that
 the keyword @code{class} is meaningless in C and Objective-C.}.
 Similarly, line 18 is assigned @code{class-close} syntax.
 
+Note that @code{class-open} and @code{class-close} syntactic elements
+have two anchor points.  The first is the position of the beginning of
+the statement, the second is the position of the keyword which defines
+the construct (e.g.  @code{class}).  These are usually the same
+position, but differ when the statement starts off with
+@code{template} (C++ Mode) or @code{generic} (Java Mode) or similar.
+
 @ssindex inher-intro
 @ssindex inher-cont
 Line 2 introduces the inheritance list for the class so it is assigned
diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 1fc02d1ad07..d903dd0694e 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -12618,7 +12618,7 @@ comment at the start of cc-engine.el for more info."
     (c-syntactic-skip-backward c-block-prefix-charset limit t)
 
     (while
-       (or 
+       (or
         ;; Could be after a template arglist....
         (and c-recognize-<>-arglists
              (eq (char-before) ?>)
@@ -14174,7 +14174,8 @@ comment at the start of cc-engine.el for more info."
 (defun c-add-class-syntax (symbol
                           containing-decl-open
                           containing-decl-start
-                          containing-decl-kwd)
+                          containing-decl-kwd
+                          &rest args)
   ;; The inclass and class-close syntactic symbols are added in
   ;; several places and some work is needed to fix everything.
   ;; Therefore it's collected here.
@@ -14189,7 +14190,7 @@ comment at the start of cc-engine.el for more info."
     ;; Ought to use `c-add-stmt-syntax' instead of backing up to boi
     ;; here, but we have to do like this for compatibility.
     (back-to-indentation)
-    (c-add-syntax symbol (point))
+    (apply #'c-add-syntax symbol (point) args)
     (if (and (c-keyword-member containing-decl-kwd
                               'c-inexpr-class-kwds)
             (/= containing-decl-start (c-point 'boi containing-decl-start)))
@@ -14223,9 +14224,10 @@ comment at the start of cc-engine.el for more info."
        ;; CASE B.1: class-open
        ((save-excursion
          (and (eq (char-after) ?{)
-              (c-looking-at-decl-block t)
+              (setq placeholder (c-looking-at-decl-block t))
               (setq beg-of-same-or-containing-stmt (point))))
-       (c-add-syntax 'class-open beg-of-same-or-containing-stmt))
+       (c-add-syntax 'class-open beg-of-same-or-containing-stmt
+                     (c-point 'boi placeholder)))
 
        ;; CASE B.2: brace-list-open
        ((or (consp special-brace-list)
@@ -14720,7 +14722,10 @@ comment at the start of cc-engine.el for more info."
                            'lambda-intro-cont)))
        (goto-char (cdr placeholder))
        (back-to-indentation)
-       (c-add-stmt-syntax tmpsymbol nil t
+       (c-add-stmt-syntax tmpsymbol
+                          (and (eq tmpsymbol 'class-open)
+                               (list (point)))
+                          t
                           (c-most-enclosing-brace state-cache (point))
                           paren-state)
        (unless (eq (point) (cdr placeholder))
@@ -14763,9 +14768,10 @@ comment at the start of cc-engine.el for more info."
              (goto-char indent-point)
              (skip-chars-forward " \t")
              (and (eq (char-after) ?{)
-                  (c-looking-at-decl-block t)
+                  (setq tmp-pos (c-looking-at-decl-block t))
                   (setq placeholder (point))))
-           (c-add-syntax 'class-open placeholder))
+           (c-add-syntax 'class-open placeholder
+                         (c-point 'boi tmp-pos)))
 
           ;; CASE 5A.3: brace list open
           ((save-excursion
@@ -15163,10 +15169,14 @@ comment at the start of cc-engine.el for more info."
         ((and containing-sexp
               (eq char-after-ip ?})
               (eq containing-decl-open containing-sexp))
+         (save-excursion
+           (goto-char containing-decl-open)
+           (setq tmp-pos (c-looking-at-decl-block t)))
          (c-add-class-syntax 'class-close
                              containing-decl-open
                              containing-decl-start
-                             containing-decl-kwd))
+                             containing-decl-kwd
+                             (c-point 'boi tmp-pos)))
 
         ;; CASE 5H: we could be looking at subsequent knr-argdecls
         ((and c-recognize-knr-p