Make syntax.c call syntax-propertize on demand

* lisp/emacs-lisp/syntax.el (syntax--jit-propertize): New function.
(parse-sexp-propertize-function): Use it.
(syntax-propertize): Disable parse-sexp-propertize-function.

* src/syntax.c (parse_sexp_propertize, update_syntax_table_forward):
New functions.
(syms_of_syntax): New vars `parse-sexp-propertize-done' and
`parse-sexp-propertize-function'.

* src/syntax.h (struct gl_state_s): Add `e_property_truncated' field.
(UPDATE_SYNTAX_TABLE_FORWARD): Use update_syntax_table_forward.
(SETUP_BUFFER_SYNTAX_TABLE): Set e_property_truncated.

* lisp/progmodes/elisp-mode.el (elisp-byte-code-syntax-propertize):
Don't assume `point' is set.

1 files changed, 3 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 2f2bd157dd7..49ce9b7eb08 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -977,6 +977,9 @@ be updated accordingly.
 
 * Lisp Changes in Emacs 25.1
 
+** syntax-propertize is now automatically called on-demand during forward
+parsing functions like `forward-sexp'.
+
 ** New hooks prefix-command-echo-keystrokes-functions and
 prefix-command-preserve-state-hook, to allow the definition of prefix
 commands other than the predefined C-u.