| Message ID | 50532B88.9060100@oracle.com |
|---|---|
| State | New |
| Headers | show |
On 09/14/2012 09:05 AM, Paolo Carlini wrote: > here we crash because strip_typedefs while processing _RequireInputIter > calls make_typename_type which returns error_mark_node (# line 3281). strip_typedefs should not return error_mark_node unless it gets error_mark_node as an argument; if a typedef-using type is valid, removing the typedefs should still produce a valid type. I ran into a similar bug when I was working on the instantiation-dependent stuff, but I don't remember which bit fixed that one. > PS: I'm also attaching a patchlet for a couple of hard errors in > make_typename_type not protected by (complain & tf_error) spotted in > make_typename_type. This patchlet is OK. Jason
Hi, On 09/14/2012 04:36 PM, Jason Merrill wrote: > On 09/14/2012 09:05 AM, Paolo Carlini wrote: >> here we crash because strip_typedefs while processing _RequireInputIter >> calls make_typename_type which returns error_mark_node (# line 3281). > > strip_typedefs should not return error_mark_node unless it gets > error_mark_node as an argument; if a typedef-using type is valid, > removing the typedefs should still produce a valid type. I see, makes sense. What I'm seeing is that make_typename_type, called for this context (the enable_if): <record_type 0x7ffff694ac78 enable_if type_0 type_5 type_6 VOID align 8 symtab 0 alias set -1 canonical type 0x7ffff694ac78 context <translation_unit_decl 0x7ffff67fd170 D.1> full-name "struct enable_if<is_convertible<int, bool>::value>" no-binfo use_template=1 interface-unknown chain <type_decl 0x7ffff694d170 enable_if>> wants to return error_mark_node, because here: if (!dependent_scope_p (context)) /* We should only set WANT_TYPE when we're a nested typename type. Then we can give better diagnostics if we find a non-type. */ t = lookup_field (context, name, 2, /*want_type=*/true); else t = NULL_TREE; if ((!t || TREE_CODE (t) == TREE_LIST) && dependent_type_p (context)) return build_typename_type (context, name, fullname, tag_type); want_template = TREE_CODE (fullname) == TEMPLATE_ID_EXPR; if (!t) { if (complain & tf_error) error (want_template ? G_("no class template named %q#T in %q#T") : G_("no type named %q#T in %q#T"), name, context); return error_mark_node; } lookup_field returns NULL_TREE and dependent_type_p (context) is false. It seems to me that the return value of lookup_field is right. Thus either dependent_type_p shouldn't be false or something is wrong in the logic or strip_typedefs should not call make_typename_type at all?!? Paolo.
On 09/14/2012 05:14 PM, Paolo Carlini wrote: > lookup_field returns NULL_TREE and dependent_type_p (context) is > false. It seems to me that the return value of lookup_field is right. No, I don't think it makes sense for lookup_field to return NULL_TREE. For our testcase we should find the nested type (or we should not call lookup_field at all here) Paolo.
Jason, H.J. figured out that this changed when case SCOPE_REF of value_dependent_expression_p started always returning true, part of the instantiation_dependent_p work... I'm unassigning myself, I guess you will immediately see which further changes are needed. Thanks! Paolo.
Index: testsuite/g++.dg/cpp0x/pr54575.C =================================================================== --- testsuite/g++.dg/cpp0x/pr54575.C (revision 0) +++ testsuite/g++.dg/cpp0x/pr54575.C (revision 0) @@ -0,0 +1,27 @@ +// PR c++/54575 +// { dg-do compile { target c++11 } } + +template<typename _From, typename _To> +struct is_convertible { static const bool value = true; }; + +template<bool> struct enable_if { }; +template<> struct enable_if<true> { typedef int type; }; + +template<typename _InIter> +using _RequireInputIter += typename enable_if<is_convertible<_InIter,bool>::value>::type; + +template<typename _Tp> +struct X +{ + template<typename _InputIterator, + typename = _RequireInputIter<_InputIterator>> + void insert(_InputIterator) {} +}; + +template<typename> +void foo() +{ + X<int> subdomain_indices; + subdomain_indices.insert(0); +} Index: cp/tree.c =================================================================== --- cp/tree.c (revision 191290) +++ cp/tree.c (working copy) @@ -1210,8 +1210,10 @@ strip_typedefs (tree t) break; } + if (result == error_mark_node) + return error_mark_node; if (!result) - result = TYPE_MAIN_VARIANT (t); + result = TYPE_MAIN_VARIANT (t); if (TYPE_USER_ALIGN (t) != TYPE_USER_ALIGN (result) || TYPE_ALIGN (t) != TYPE_ALIGN (result)) { Index: cp/pt.c =================================================================== --- cp/pt.c (revision 191290) +++ cp/pt.c (working copy) @@ -6114,6 +6114,8 @@ canonicalize_type_argument (tree arg, tsubst_flags return arg; mv = TYPE_MAIN_VARIANT (arg); arg = strip_typedefs (arg); + if (arg == error_mark_node) + return error_mark_node; if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv) || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv)) {
Hi, here we crash because strip_typedefs while processing _RequireInputIter calls make_typename_type which returns error_mark_node (# line 3281). Thus I'm simply checking for result == error_mark_node right after the switch (in the switch finish_decltype_type could also return error_mark_node, for example) and before handling the alignment (where we are crashing now). Issue seems rather straightforward. Tested x86_64-linux. Thanks, Paolo. PS: I'm also attaching a patchlet for a couple of hard errors in make_typename_type not protected by (complain & tf_error) spotted in make_typename_type. ///////////////////////// /cp 2012-09-14 Paolo Carlini <paolo.carlini@oracle.com> PR c++/54575 * tree.c (strip_typedefs): Check result for error_mark_node. * pt.c (canonicalize_type_argument): Check strip_typedefs return value for error_mark_node. /testsuite 2012-09-14 Paolo Carlini <paolo.carlini@oracle.com> PR c++/54575 * g++.dg/cpp0x/pr54575.C: New. 2012-09-14 Paolo Carlini <paolo.carlini@oracle.com> * decl.c (make_typename_type): Only error out if tf_error is set in complain. Index: decl.c =================================================================== --- decl.c (revision 191290) +++ decl.c (working copy) @@ -3235,13 +3235,15 @@ make_typename_type (tree context, tree name, enum name = TREE_OPERAND (fullname, 0) = DECL_NAME (name); else if (TREE_CODE (name) == OVERLOAD) { - error ("%qD is not a type", name); + if (complain & tf_error) + error ("%qD is not a type", name); return error_mark_node; } } if (TREE_CODE (name) == TEMPLATE_DECL) { - error ("%qD used without template parameters", name); + if (complain & tf_error) + error ("%qD used without template parameters", name); return error_mark_node; } gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE);