bug#10792: 24.0.93; emacs goes comatose opening C header

[Alan Mackenzie]

Hello, Eli.

On Sat, Feb 11, 2012 at 10:17:55PM +0200, Eli Zaretskii wrote:
> > Date: Sat, 11 Feb 2012 20:05:07 +0000
> > From: Alan Mackenzie <acm@muc.de>
> > Cc: 10792@debbugs.gnu.org

> > On Sat, Feb 11, 2012 at 12:26:36PM -0500, John Yates wrote:
> > > When I attemt to visit the following header emacs locks up.  If
> > > I make the contents of the macro significantly shorted emacs is
> > > able to open and fontlock it successfully.  To me this suggests
> > > some form of n-squared processing.

> > For once, this problem has nothing to do with font locking.

> It doesn't?

It hangs for me with font lock disabled.

> If I attach GDB to Emacs, I get this Lisp backtrace:

>   Lisp Backtrace:
>   "c-end-of-macro" (0x827d74)
>   "c-syntactic-end-of-macro" (0x827fc4)
>   "c-state-safe-place" (0x828224)
>   "c-literal-limits" (0x828484)
>   "c-set-fl-decl-start" (0x8286d4)
>   "c-context-set-fl-decl-start" (0x828924)
>   0x3422320 PVEC_COMPILED
>   "mapc" (0x828d04)
>   "c-font-lock-fontify-region" (0x828f54) <<<<<<<<<<<<<<<<<<<<<
>   "font-lock-fontify-region" (0x8292d8)   <<<<<<<<<<<<<<<<<<<<<
>   "run-hook-with-args" (0x8292d4)
>   "byte-code" (0x8294a0)
>   "jit-lock-fontify-now" (0x829894)       <<<<<<<<<<<<<<<<<<<<<
>   "jit-lock-function" (0x829c24)          <<<<<<<<<<<<<<<<<<<<<
>   "recenter" (0x82f6b4)
>   "end-of-buffer" (0x82f954)
>   "call-interactively" (0x82fb84)

> > It happens when the buffer length exceeds 3000 bytes.  :-)

> You mean, the macro definition length, right?

Sorry, yes.

-- 
Alan Mackenzie (Nuremberg, Germany).