Emacs CEDET Semantic tag folding

Question

I would like that every time I open a .cpp file, semantic tag-folding would become activated. I am using the latest version of cedet (loading cedet-devel-load.el). I have

(semantic-mode 1)
(require 'semantic/ia)
(require 'semantic/bovine/gcc)
(load-file "path/to/semantic/tag/folding/semantic-tag-folding.el")
(require 'semantic-tag-folding)

I added a hook

(add-hook 'c-mode-common-hook 'setupcpp)

and in 'setupcpp I simply have

(defun setupcpp ()
(interactive)
(semantic-tag-folding-mode t))

Nothing related to cedet/semantic happens after this in my .emacs. In fact, I could make this the only content of my .emacs.

It doesn't work. When opening a .cpp file I get the message File mode specification error: (error "Buffer foo.cpp cannot be folded by semantic").

Weirdly enough, if, once the file is open, I do M-x semantic-tag-folding-mode, it works! I am just lost.

Answer 1

I got exactly the same error, using Emacs 24.3 and the newest cedet bzr version.

My solution is the following: Whenever something is decorated, the folding-mode will be enabled, too.

(load-library "~/emacs/cedet/cedet-bzr/trunk/cedet-devel-load")
(load-library "contrib/semantic-tag-folding.el")

(defun do-after-decorate () (semantic-tag-folding-mode t) )
(add-hook 'semantic-decoration-mode-hook 'do-after-decorate) 
;; ... 
(semantic-load-enable-excessive-code-helpers) ; also starts the decorate-mode when useful.

Works for me.