1 files changed, 104 insertions, 37 deletions

diff --git a/src/syntax.c b/src/syntax.c
index dc82210e79d..cacdf18c2a2 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -181,6 +181,7 @@ static void scan_sexps_forward (struct lisp_parse_state *,
                                 ptrdiff_t, ptrdiff_t, ptrdiff_t, EMACS_INT,
                                 bool, Lisp_Object, int);
 static bool in_classes (int, Lisp_Object);
+static void parse_sexp_propertize (ptrdiff_t charpos);
 
 /* This setter is used only in this file, so it can be private.  */
 static void
@@ -246,8 +247,15 @@ SETUP_SYNTAX_TABLE (ptrdiff_t from, ptrdiff_t count)
   gl_state.object = Qnil;
   gl_state.offset = 0;
   if (parse_sexp_lookup_properties)
-    if (count > 0 || from > BEGV)
-      update_syntax_table (count > 0 ? from : from - 1, count, 1, Qnil);
+    {
+      if (count > 0)
+        update_syntax_table_forward (from, true, Qnil);
+      else if (from > BEGV)
+        {
+          update_syntax_table (from - 1, count, true, Qnil);
+          parse_sexp_propertize (from - 1);
+        }
+    }
 }
 
 /* Same as above, but in OBJECT.  If OBJECT is nil, use current buffer.
@@ -313,7 +321,7 @@ update_syntax_table (ptrdiff_t charpos, EMACS_INT count, bool init,
 {
   Lisp_Object tmp_table;
   int cnt = 0;
-  bool invalidate = 1;
+  bool invalidate = true;
   INTERVAL i;
 
   if (init)
@@ -323,7 +331,7 @@ update_syntax_table (ptrdiff_t charpos, EMACS_INT count, bool init,
       gl_state.stop = gl_state.e_property;
       i = interval_of (charpos, object);
       gl_state.backward_i = gl_state.forward_i = i;
-      invalidate = 0;
+      invalidate = false;
       if (!i)
         return;
       /* interval_of updates only ->position of the return value, so
@@ -359,7 +367,7 @@ update_syntax_table (ptrdiff_t charpos, EMACS_INT count, bool init,
       i = update_interval (i, charpos);
       if (INTERVAL_LAST_POS (i) != gl_state.b_property)
         {
-          invalidate = 0;
+          invalidate = false;
           gl_state.forward_i = i;
           gl_state.e_property = INTERVAL_LAST_POS (i) - gl_state.offset;
         }
@@ -372,7 +380,7 @@ update_syntax_table (ptrdiff_t charpos, EMACS_INT count, bool init,
       i = update_interval (i, charpos);
       if (i->position != gl_state.e_property)
         {
-          invalidate = 0;
+          invalidate = false;
           gl_state.backward_i = i;
           gl_state.b_property = i->position - gl_state.offset;
         }
@@ -460,14 +468,69 @@ update_syntax_table (ptrdiff_t charpos, EMACS_INT count, bool init,
     }
   eassert (i == NULL); /* This property goes to the end.  */
   if (count > 0)
-    gl_state.e_property = gl_state.stop;
+    {
+      gl_state.e_property = gl_state.stop;
+      gl_state.forward_i = i;
+    }
   else
     gl_state.b_property = gl_state.start;
 }
+
+static void
+parse_sexp_propertize (ptrdiff_t charpos)
+{
+  EMACS_INT zv = ZV;
+  if (syntax_propertize__done <= charpos
+      && syntax_propertize__done < zv)
+    {
+      EMACS_INT modiffs = CHARS_MODIFF;
+      safe_call1 (Qinternal__syntax_propertize,
+                  make_number (min (zv, 1 + charpos)));
+      if (modiffs != CHARS_MODIFF)
+        error ("parse-sexp-propertize-function modified the buffer!");
+      if (syntax_propertize__done <= charpos
+          && syntax_propertize__done < zv)
+        error ("parse-sexp-propertize-function did not move"
+               " syntax-propertize--done");
+      SETUP_SYNTAX_TABLE (charpos, 1);
+    }
+  else if (gl_state.e_property > syntax_propertize__done)
+    {
+      gl_state.e_property = syntax_propertize__done;
+      gl_state.e_property_truncated = true;
+    }
+  else if (gl_state.e_property_truncated
+           && gl_state.e_property < syntax_propertize__done)
+    { /* When moving backward, e_property might be set without resetting
+         e_property_truncated, so the e_property_truncated flag may
+         occasionally be left raised spuriously.  This should be rare.  */
+      gl_state.e_property_truncated = false;
+      update_syntax_table_forward (charpos, false, Qnil);
+    }
+}
+
+void
+update_syntax_table_forward (ptrdiff_t charpos, bool init,
+                             Lisp_Object object)
+{
+  if (gl_state.e_property_truncated)
+    {
+      eassert (NILP (object));
+      eassert (charpos >= gl_state.e_property);
+      parse_sexp_propertize (charpos);
+    }
+  else
+    {
+      update_syntax_table (charpos, 1, init, object);
+      if (gl_state.e_property > syntax_propertize__done
+          && NILP (object))
+        parse_sexp_propertize (charpos);
+    }
+}
 
 /* Returns true if char at CHARPOS is quoted.
    Global syntax-table data should be set up already to be good at CHARPOS
-   or after.  On return global syntax data is good for lookup at CHARPOS. */
+   or after.  On return global syntax data is good for lookup at CHARPOS.  */
 
 static bool
 char_quoted (ptrdiff_t charpos, ptrdiff_t bytepos)
@@ -628,7 +691,7 @@ back_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
      OFROM[I] is position of the earliest comment-starter seen
      which is I+2X quotes from the comment-end.
      PARITY is current parity of quotes from the comment end.  */
-  int string_style = -1;        /* Presumed outside of any string. */
+  int string_style = -1;        /* Presumed outside of any string.  */
   bool string_lossage = 0;
   /* Not a real lossage: indicates that we have passed a matching comment
      starter plus a non-matching comment-ender, meaning that any matching
@@ -645,7 +708,7 @@ back_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
   ptrdiff_t defun_start = 0;
   ptrdiff_t defun_start_byte = 0;
   enum syntaxcode code;
-  ptrdiff_t nesting = 1;                /* current comment nesting */
+  ptrdiff_t nesting = 1;                /* Current comment nesting.  */
   int c;
   int syntax = 0;
 
@@ -876,7 +939,7 @@ back_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
                    is nested, so we need to try again from within the
                    surrounding comment.  Example: { a (* " *)  */
                 {
-                  /* FIXME: We should advance by one or two chars. */
+                  /* FIXME: We should advance by one or two chars.  */
                   defun_start = state.comstr_start + 2;
                   defun_start_byte = CHAR_TO_BYTE (defun_start);
                 }
@@ -1042,7 +1105,7 @@ DEFUN ("string-to-syntax", Fstring_to_syntax, Sstring_to_syntax, 1, 1, 0,
        doc: /* Convert a syntax descriptor STRING into a raw syntax descriptor.
 STRING should be a string of the form allowed as argument of
 `modify-syntax-entry'.  The return value is a raw syntax descriptor: a
-cons cell \(CODE . MATCHING-CHAR) which can be used, for example, as
+cons cell (CODE . MATCHING-CHAR) which can be used, for example, as
 the value of a `syntax-table' text property.  */)
   (Lisp_Object string)
 {
@@ -2288,13 +2351,13 @@ forw_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
           && SYNTAX_FLAGS_COMMENT_STYLE (syntax, 0) == style
           && (SYNTAX_FLAGS_COMMENT_NESTED (syntax) ?
               (nesting > 0 && --nesting == 0) : nesting < 0))
-        /* we have encountered a comment end of the same style
+        /* We have encountered a comment end of the same style
            as the comment sequence which began this comment
-           section */
+           section.  */
         break;
       if (code == Scomment_fence
           && style == ST_COMMENT_STYLE)
-        /* we have encountered a comment end of the same style
+        /* We have encountered a comment end of the same style
            as the comment sequence which began this comment
            section.  */
         break;
@@ -2302,8 +2365,8 @@ forw_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
           && code == Scomment
           && SYNTAX_FLAGS_COMMENT_NESTED (syntax)
           && SYNTAX_FLAGS_COMMENT_STYLE (syntax, 0) == style)
-        /* we have encountered a nested comment of the same style
-           as the comment sequence which began this comment section */
+        /* We have encountered a nested comment of the same style
+           as the comment sequence which began this comment section.  */
         nesting++;
       INC_BOTH (from, from_byte);
       UPDATE_SYNTAX_TABLE_FORWARD (from);
@@ -2319,9 +2382,8 @@ forw_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
               ? nesting > 0 : nesting < 0))
         {
           if (--nesting <= 0)
-            /* we have encountered a comment end of the same style
-               as the comment sequence which began this comment
-               section */
+            /* We have encountered a comment end of the same style
+               as the comment sequence which began this comment section.  */
             break;
           else
             {
@@ -2338,9 +2400,8 @@ forw_comment (ptrdiff_t from, ptrdiff_t from_byte, ptrdiff_t stop,
               && SYNTAX_FLAGS_COMSTART_SECOND (other_syntax))
           && (SYNTAX_FLAGS_COMMENT_NESTED (syntax) ||
               SYNTAX_FLAGS_COMMENT_NESTED (other_syntax)))
-        /* we have encountered a nested comment of the same style
-           as the comment sequence which began this comment
-           section */
+        /* We have encountered a nested comment of the same style
+           as the comment sequence which began this comment section.  */
         {
           INC_BOTH (from, from_byte);
           UPDATE_SYNTAX_TABLE_FORWARD (from);
@@ -2584,9 +2645,9 @@ scan_lists (EMACS_INT from, EMACS_INT count, EMACS_INT depth, bool sexpflag)
   bool quoted;
   bool mathexit = 0;
   enum syntaxcode code;
-  EMACS_INT min_depth = depth;    /* Err out if depth gets less than this.  */
-  int comstyle = 0;         /* style of comment encountered */
-  bool comnested = 0;       /* whether the comment is nestable or not */
+  EMACS_INT min_depth = depth;  /* Err out if depth gets less than this.  */
+  int comstyle = 0;             /* Style of comment encountered.  */
+  bool comnested = 0;           /* Whether the comment is nestable or not.  */
   ptrdiff_t temp_pos;
   EMACS_INT last_good = from;
   bool found;
@@ -2630,11 +2691,11 @@ scan_lists (EMACS_INT from, EMACS_INT count, EMACS_INT depth, bool sexpflag)
                   SYNTAX_FLAGS_COMSTART_SECOND (other_syntax))
               && parse_sexp_ignore_comments)
             {
-              /* we have encountered a comment start sequence and we
+              /* We have encountered a comment start sequence and we
                  are ignoring all text inside comments.  We must record
                  the comment style this sequence begins so that later,
                  only a comment end of the same style actually ends
-                 the comment section */
+                 the comment section.  */
               code = Scomment;
               comstyle = SYNTAX_FLAGS_COMMENT_STYLE (other_syntax, syntax);
               comnested |= SYNTAX_FLAGS_COMMENT_NESTED (other_syntax);
@@ -2652,7 +2713,7 @@ scan_lists (EMACS_INT from, EMACS_INT count, EMACS_INT depth, bool sexpflag)
               if (from == stop)
                 goto lose;
               INC_BOTH (from, from_byte);
-              /* treat following character as a word constituent */
+              /* Treat following character as a word constituent.  */
             case Sword:
             case Ssymbol:
               if (depth || !sexpflag) break;
@@ -2745,12 +2806,8 @@ scan_lists (EMACS_INT from, EMACS_INT count, EMACS_INT depth, bool sexpflag)
                       : c_code == Sstring_fence)
                     break;
 
-                  switch (c_code)
-                    {
-                    case Scharquote:
-                    case Sescape:
-                      INC_BOTH (from, from_byte);
-                    }
+                  if (c_code == Scharquote || c_code == Sescape)
+                    INC_BOTH (from, from_byte);
                   INC_BOTH (from, from_byte);
                 }
               INC_BOTH (from, from_byte);
@@ -3365,11 +3422,16 @@ do { prev_from = from;				\
                   case Sstring_fence:
                     if (!nofence) goto string_end;
                     break;
+
                   case Scharquote:
                   case Sescape:
                     INC_FROM;
                   startquotedinstring:
                     if (from >= end) goto endquoted;
+                    break;
+
+                  default:
+                    break;
                   }
                 INC_FROM;
               }
@@ -3457,7 +3519,7 @@ Sixth arg COMMENTSTOP non-nil means stop at the start of a comment.
       target = XINT (targetdepth);
     }
   else
-    target = TYPE_MINIMUM (EMACS_INT);  /* We won't reach this depth */
+    target = TYPE_MINIMUM (EMACS_INT);  /* We won't reach this depth.  */
 
   validate_region (&from, &to);
   scan_sexps_forward (&state, XINT (from), CHAR_TO_BYTE (XINT (from)),
@@ -3588,7 +3650,7 @@ syms_of_syntax (void)
   staticpro (&gl_state.current_syntax_table);
   staticpro (&gl_state.old_prop);
 
-  /* Defined in regex.c */
+  /* Defined in regex.c.  */
   staticpro (&re_match_object);
 
   DEFSYM (Qscan_error, "scan-error");
@@ -3606,6 +3668,11 @@ Otherwise, that text property is simply ignored.
 See the info node `(elisp)Syntax Properties' for a description of the
 `syntax-table' property.  */);
 
+  DEFVAR_INT ("syntax-propertize--done", syntax_propertize__done,
+              doc: /* Position up to which syntax-table properties have been set.  */);
+  syntax_propertize__done = -1;
+  DEFSYM (Qinternal__syntax_propertize, "internal--syntax-propertize");
+
   words_include_escapes = 0;
   DEFVAR_BOOL ("words-include-escapes", words_include_escapes,
                doc: /* Non-nil means `forward-word', etc., should treat escape chars part of words.  */);