(scan_lists): Signal errors using scan-error.

(syms_of_syntax): Set up Qscan_error.

1 files changed, 26 insertions, 4 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 22339930b2b..1404bfab249 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -26,7 +26,7 @@ Boston, MA 02111-1307, USA.  */
 #include "buffer.h"
 #include "syntax.h"
 
-Lisp_Object Qsyntax_table_p, Qsyntax_table;
+Lisp_Object Qsyntax_table_p, Qsyntax_table, Qscan_error;
 
 static void scan_sexps_forward ();
 static int char_quoted ();
@@ -943,6 +943,7 @@ scan_lists (from, count, depth, sexpflag)
   register enum syntaxcode code;
   int min_depth = depth;    /* Err out if depth gets less than this. */
   int comstyle = 0;         /* style of comment encountered */
+  int last_good = from;
 
   if (depth > 0) min_depth = 0;
 
@@ -956,6 +957,8 @@ scan_lists (from, count, depth, sexpflag)
         {
           c = FETCH_CHAR (from);
           code = SYNTAX (c);
+          if (depth == min_depth)
+            last_good = from;
           from++;
           if (from < stop && SYNTAX_COMSTART_FIRST (c)
               && SYNTAX_COMSTART_SECOND (FETCH_CHAR (from))
@@ -1053,7 +1056,10 @@ scan_lists (from, count, depth, sexpflag)
             close1:
               if (!--depth) goto done;
               if (depth < min_depth)
-                error ("Containing expression ends prematurely");
+                Fsignal (Qscan_error,
+                         Fcons (build_string ("Containing expression ends prematurely"),
+                                Fcons (make_number (last_good),
+                                       Fcons (make_number (from), Qnil))));
               break;
 
             case Sstring:
@@ -1097,6 +1103,8 @@ scan_lists (from, count, depth, sexpflag)
             from--;
           c = FETCH_CHAR (from);
           code = SYNTAX (c);
+          if (depth == min_depth)
+            last_good = from;
           comstyle = 0;
           if (code == Sendcomment)
             comstyle = SYNTAX_COMMENT_STYLE (c);
@@ -1155,7 +1163,10 @@ scan_lists (from, count, depth, sexpflag)
             open2:
               if (!--depth) goto done2;
               if (depth < min_depth)
-                error ("Containing expression ends prematurely");
+                Fsignal (Qscan_error,
+                         Fcons (build_string ("Containing expression ends prematurely"),
+                                Fcons (make_number (last_good),
+                                       Fcons (make_number (from), Qnil))));
               break;
 
             case Sendcomment:
@@ -1331,7 +1342,11 @@ scan_lists (from, count, depth, sexpflag)
   return val;
 
  lose:
-  error ("Unbalanced parentheses");
+  Fsignal (Qscan_error,
+           Fcons (build_string ("Unbalanced parentheses"),
+                  Fcons (make_number (last_good),
+                         Fcons (make_number (from), Qnil))));
+
   /* NOTREACHED */
 }
 
@@ -1796,6 +1811,13 @@ syms_of_syntax ()
   Qsyntax_table_p = intern ("syntax-table-p");
   staticpro (&Qsyntax_table_p);
 
+  Qscan_error = intern ("scan-error");
+  staticpro (&Qscan_error);
+  Fput (Qscan_error, Qerror_conditions,
+        Fcons (Qerror, Qnil));
+  Fput (Qscan_error, Qerror_message,
+        build_string ("Scan error"));
+
   DEFVAR_BOOL ("parse-sexp-ignore-comments", &parse_sexp_ignore_comments,
     "Non-nil means `forward-sexp', etc., should treat comments as whitespace.");