[C++ Patch] PR 58503
Paolo Carlini
paolo.carlini@oracle.com
Thu Oct 3 09:52:00 GMT 2013
Hi,
in this error recovery issue in template context,
do_range_for_auto_deduction calls cp_parser_perform_range_for_lookup,
which can't resolve begin/end and eventually crashes because TREE_TYPE
(*begin) and TREE_TYPE (*end) are NULL_TREE.
It doesn't seem correct to simply early return error_mark_node, because
the errors at issue are the permerror(s) produced by
unqualified_fn_lookup_error. However, returning NULL_TREE, while
adjusting do_range_for_auto_deduction to do nothing when the return type
of begin/end isn't known, like in the case at issue, appears to work
fine (I also checked that with -fpermissive an eventual instantiation
produces hard errors, as it should)
Tested x86_64-linux.
Thanks,
Paolo.
////////////////////////
-------------- next part --------------
/cp
2013-10-03 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/58503
* parser.c (cp_parser_perform_range_for_lookup): If either TREE_TYPE
of *begin or *end is NULL_TREE, return NULL_TREE.
(do_range_for_auto_deduction): If cp_parser_perform_range_for_lookup
returns NULL_TREE, don't actually do_auto_deduction.
/testsuite
2013-10-03 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/58503
* g++.dg/cpp0x/range-for26.C: New.
-------------- next part --------------
Index: cp/parser.c
===================================================================
--- cp/parser.c (revision 203152)
+++ cp/parser.c (working copy)
@@ -9960,11 +9960,15 @@ do_range_for_auto_deduction (tree decl, tree range
range_temp = convert_from_reference (build_range_temp (range_expr));
iter_type = (cp_parser_perform_range_for_lookup
(range_temp, &begin_dummy, &end_dummy));
- iter_decl = build_decl (input_location, VAR_DECL, NULL_TREE, iter_type);
- iter_decl = build_x_indirect_ref (input_location, iter_decl, RO_NULL,
- tf_warning_or_error);
- TREE_TYPE (decl) = do_auto_deduction (TREE_TYPE (decl),
- iter_decl, auto_node);
+ if (iter_type)
+ {
+ iter_decl = build_decl (input_location, VAR_DECL, NULL_TREE,
+ iter_type);
+ iter_decl = build_x_indirect_ref (input_location, iter_decl, RO_NULL,
+ tf_warning_or_error);
+ TREE_TYPE (decl) = do_auto_deduction (TREE_TYPE (decl),
+ iter_decl, auto_node);
+ }
}
}
@@ -10171,6 +10175,10 @@ cp_parser_perform_range_for_lookup (tree range, tr
*begin = *end = error_mark_node;
return error_mark_node;
}
+ else if (!TREE_TYPE (*begin) || !TREE_TYPE (*end))
+ /* Can happen, when, eg, in a template context, Koenig lookup
+ can't resolve begin/end (c++/58503). */
+ return NULL_TREE;
else
{
tree iter_type = cv_unqualified (TREE_TYPE (*begin));
Index: testsuite/g++.dg/cpp0x/range-for26.C
===================================================================
--- testsuite/g++.dg/cpp0x/range-for26.C (revision 0)
+++ testsuite/g++.dg/cpp0x/range-for26.C (working copy)
@@ -0,0 +1,7 @@
+// PR c++/58503
+// { dg-require-effective-target c++11 }
+
+template<int> void foo()
+{
+ for (auto i : 0) {} // { dg-error "there are no arguments" }
+}
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