diff -r 927afb7bca2a -r c76e42112584 Parser/Python.asdl
--- a/Parser/Python.asdl	Sat Jan 05 21:20:29 2013 +0100
+++ b/Parser/Python.asdl	Sun Jan 06 21:28:18 2013 +0100
@@ -106,8 +106,11 @@
     arguments = (arg* args, identifier? vararg, expr? varargannotation,
                      arg* kwonlyargs, identifier? kwarg,
                      expr? kwargannotation, expr* defaults,
-                     expr* kw_defaults)
-    arg = (identifier arg, expr? annotation)
+                     expr* kw_defaults,
+                     int? vararg_lineno, int? vararg_col_offset,
+                     int? kwarg_lineno, int? kwarg_col_offset)
+    arg = (identifier arg, expr? annotation,
+           int? lineno, int? col_offset)
 
     -- keyword arguments supplied to call
     keyword = (identifier arg, expr value)
diff -r 927afb7bca2a -r c76e42112584 Python/ast.c
--- a/Python/ast.c	Sat Jan 05 21:20:29 2013 +0100
+++ b/Python/ast.c	Sun Jan 06 21:28:18 2013 +0100
@@ -1138,7 +1138,7 @@
             return NULL;
     }
 
-    return arg(name, annotation, c->c_arena);
+    return arg(name, annotation, n->n_lineno, n->n_col_offset, c->c_arena);
 }
 
 /* returns -1 if failed to handle keyword only arguments
@@ -1193,7 +1193,7 @@
                     goto error;
                 if (forbidden_name(c, argname, ch, 0))
                     goto error;
-                arg = arg(argname, annotation, c->c_arena);
+                arg = arg(argname, annotation, ch->n_lineno, ch->n_col_offset, c->c_arena);
                 if (!arg)
                     goto error;
                 asdl_seq_SET(kwonlyargs, j++, arg);
@@ -1232,6 +1232,7 @@
        vfpdef: NAME
     */
     int i, j, k, nposargs = 0, nkwonlyargs = 0;
+    int vararg_lineno = 0, vararg_col_offset = 0, kwarg_lineno = 0, kwarg_col_offset = 0;
     int nposdefaults = 0, found_default = 0;
     asdl_seq *posargs, *posdefaults, *kwonlyargs, *kwdefaults;
     identifier vararg = NULL, kwarg = NULL;
@@ -1242,7 +1243,8 @@
     if (TYPE(n) == parameters) {
         if (NCH(n) == 2) /* () as argument list */
             return arguments(NULL, NULL, NULL, NULL, NULL, NULL, NULL,
-                             NULL, c->c_arena);
+                             NULL, vararg_lineno, vararg_col_offset,
+                             kwarg_lineno, kwarg_col_offset, c->c_arena);
         n = CHILD(n, 1);
     }
     assert(TYPE(n) == typedargslist || TYPE(n) == varargslist);
@@ -1351,6 +1353,8 @@
                     vararg = NEW_IDENTIFIER(CHILD(ch, 0));
                     if (!vararg)
                         return NULL;
+                    vararg_lineno = CHILD(ch, 0)->n_lineno;
+                    vararg_col_offset = CHILD(ch, 0)->n_col_offset;
                     if (forbidden_name(c, vararg, CHILD(ch, 0), 0))
                         return NULL;
                     if (NCH(ch) > 1) {
@@ -1376,6 +1380,8 @@
                 kwarg = NEW_IDENTIFIER(CHILD(ch, 0));
                 if (!kwarg)
                     return NULL;
+                kwarg_lineno = CHILD(ch, 0)->n_lineno;
+                kwarg_col_offset = CHILD(ch, 0)->n_col_offset;
                 if (NCH(ch) > 1) {
                     /* there is an annotation on the kwarg */
                     kwargannotation = ast_for_expr(c, CHILD(ch, 2));
@@ -1394,7 +1400,9 @@
         }
     }
     return arguments(posargs, vararg, varargannotation, kwonlyargs, kwarg,
-                    kwargannotation, posdefaults, kwdefaults, c->c_arena);
+                    kwargannotation, posdefaults, kwdefaults,
+                    vararg_lineno, vararg_col_offset,
+                    kwarg_lineno, kwarg_col_offset, c->c_arena);
 }
 
 static expr_ty
@@ -1560,7 +1568,7 @@
 
     if (NCH(n) == 3) {
         args = arguments(NULL, NULL, NULL, NULL, NULL, NULL, NULL,
-                         NULL, c->c_arena);
+                         NULL, 0, 0, 0, 0, c->c_arena);
         if (!args)
             return NULL;
         expression = ast_for_expr(c, CHILD(n, 2));
@@ -2103,15 +2111,19 @@
         if (NCH(n) == 2)
             return Call(left_expr, NULL, NULL, NULL, NULL, LINENO(n),
                         n->n_col_offset, c->c_arena);
-        else
-            return ast_for_call(c, CHILD(n, 1), left_expr);
+        else {
+            expr_ty tmp = ast_for_call(c, CHILD(n, 1), left_expr);
+            tmp->lineno = LINENO(n);
+            tmp->col_offset = n->n_col_offset;
+            return tmp;
+        }
     }
     else if (TYPE(CHILD(n, 0)) == DOT ) {
         PyObject *attr_id = NEW_IDENTIFIER(CHILD(n, 1));
         if (!attr_id)
             return NULL;
         return Attribute(left_expr, attr_id, Load,
-                         LINENO(n), n->n_col_offset, c->c_arena);
+                         LINENO(CHILD(n, 1)), CHILD(n, 1)->n_col_offset, c->c_arena);
     }
     else {
         REQ(CHILD(n, 0), LSQB);
@@ -2212,8 +2224,6 @@
         tmp = ast_for_trailer(c, ch, e);
         if (!tmp)
             return NULL;
-        tmp->lineno = e->lineno;
-        tmp->col_offset = e->col_offset;
         e = tmp;
     }
     if (TYPE(CHILD(n, NCH(n) - 1)) == factor) {