Lisp nesting exceeds ‘max-lisp-eval-depth’ error

[galeo]

When trying to call functionjit-lock-fontify-now, this errror will occur.

Here is the backtrace log:

Debugger entered--Lisp error: (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
  #f(compiled-function (matched names) #)(nil #)
  #f(compiled-function (elt) #)(#)
  mapc(#f(compiled-function (elt) #) (# #))
  seq-do(#f(compiled-function (elt) #) (# #))
  seq-reduce(#f(compiled-function (matched names) #) (# #) nil)
  #f(compiled-function (pos limit) #)(7758 18354)
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  ...
  ....[lots of same lines]...
  ....
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-expr(18354 #f(compiled-function (pos limit) #))
  swift-mode:font-lock-match-builtin-enum-case-names(18354)
  font-lock-fontify-keywords-region(1519 18354 nil)
  font-lock-default-fontify-region(1519 18354 nil)
  font-lock-fontify-region(1519 18354)
  #f(compiled-function (fun) #)(font-lock-fontify-region)
  run-hook-wrapped(#f(compiled-function (fun) #) font-lock-fontify-region)
  jit-lock--run-functions(1519 18354)
  jit-lock-fontify-now()

Restart emacs, and when it tries to restore the previously opened swift file, it will freeze. By executing the C-g key serveral times, it will return to normal, and there will be the following output in *Messages* buffer:

Error during redisplay: (internal--syntax-propertize 1442) signaled (quit)
Error during redisplay: (internal--syntax-propertize 4000) signaled (quit)
Error during redisplay: (internal--syntax-propertize 6042) signaled (quit)
Error during redisplay: (internal--syntax-propertize 8248) signaled (quit)
Error during redisplay: (internal--syntax-propertize 10546) signaled (quit)
Error during redisplay: (internal--syntax-propertize 12685) signaled (quit)
Error during redisplay: (internal--syntax-propertize 14710) signaled (quit)
Error during redisplay: (internal--syntax-propertize 16795) signaled (quit)

[taku0]

Thank you for reporting. Fixed by 5597eaf, hopefully.
The fix will soon be deployed to MELPA in few days. Could you try it from MELPA or master branch?

[galeo]

Thanks for the fix. It works well when trying to call jit-lock-fontify-now. However, emacs still freezes when trying to restore the previously opened swift file at startup. Act as before, the *Messages* buffer will have a slight difference in output:

Error during redisplay: (internal--syntax-propertize 1437) signaled (quit)
Error during redisplay: (internal--syntax-propertize 3799) signaled (quit)
Error during redisplay: (internal--syntax-propertize 5863) signaled (quit)
Error during redisplay: (internal--syntax-propertize 7962) signaled (quit)
Error during redisplay: (internal--syntax-propertize 10068) signaled (quit)
Error during redisplay: (internal--syntax-propertize 12188) signaled (quit)
Error during redisplay: (internal--syntax-propertize 14213) signaled (quit)
Error during redisplay: (internal--syntax-propertize 16298) signaled (quit)

The swift file used for testing is the same. I don't know how to debug this problem.

[taku0]

I guess font-locking is just slow. I have no idea how to improve it.