Hi,

I narrowed it down to a "#define anything(" as the last line in the buffer will consistently lock up for me.  I'm sure it's the c mode not resolving something right.  I will experiment more and send you the results if I can reproduce with minimal buffer content.

Thanks

On Thu, Jan 24, 2019, 8:46 AM Eli Zaretskii <eliz@gnu.org wrote:
> From: Michael Menefee <mpmenefee@gmail.com>
> Date: Wed, 23 Jan 2019 10:24:09 -0600
>
> Editing a C header file, I type
> '#define AVL_iter(' and it locks up consistently and has to be killed
> from another terminal, with CPU at 100%.

I cannot reproduce this.  Does the buffer contain anything else in
addition to the text you've shown?  Does it happen in "emacs -Q"?

I invoked "emacs -Q", then typed

  C-x C-f headerhang.h
  #define AVL_iter(

At that point, Emacs was responsive as I'd expect.  Are you doing the
same to reproduce the problem?

Thanks.