[C++ Patch] PR 84423 ("[6/7/8/9 Regression] [concepts] ICE with invalid using declaration")
Paolo Carlini
paolo.carlini@oracle.com
Fri Sep 28 20:26:00 GMT 2018
Hi,
On 9/28/18 7:18 PM, Jason Merrill wrote:
> On Fri, Sep 28, 2018 at 12:42 PM, Paolo Carlini
> <paolo.carlini@oracle.com> wrote:
>> Hi,
>>
>> the primary issue here is a rather straightforward error-recovery, where,
>> after a sensible (but see below) error message we ICE in
>> get_underlying_template - called by convert_template_argument - because we
>> don't handle correctly error_mark_node as TREE_TYPE, as set in
>> grokdeclarator. While working on it I noticed that the error message emitted
>> by grokdeclarator seems suboptimal, because, per 10.1.3/2, we correctly
>> handle the alias declaration like a typedef but, I believe, we don't want to
>> just say *typedef* in the error message: luckily the infrastructure to be
>> more accurate is fully available, because we need it to set
>> TYPE_DECL_ALIAS_P anyway.
> OK, though as long as you're messing with this error you might want to
> improve its location as well.
Thanks. About the location, you are certainly right, but doesn't seem
trivial. Something we can do *now* is using
declspecs->locations[ds_typedef] and declspecs->locations[ds_alias], but
that gives us the location of the keyword 'typedef' and 'using',
respectively, whereas I think that we would like to have the location of
'auto' itself. I could look into that as a follow-up piece work (by the
way, I'm always reluctant to embark in non trivial work having to do
with locations because I suppose David is already on it?!?)
Paolo.
///////////////////
-------------- next part --------------
Index: constraint.cc
===================================================================
--- constraint.cc (revision 264687)
+++ constraint.cc (working copy)
@@ -1164,6 +1164,9 @@ build_constraints (tree tmpl_reqs, tree decl_reqs)
if (!tmpl_reqs && !decl_reqs)
return NULL_TREE;
+ //if (tmpl_reqs == error_mark_node || decl_reqs == error_mark_node)
+ //return NULL_TREE;
+
tree_constraint_info* ci = build_constraint_info ();
ci->template_reqs = tmpl_reqs;
ci->declarator_reqs = decl_reqs;
Index: decl.c
===================================================================
--- decl.c (revision 264687)
+++ decl.c (working copy)
@@ -11879,6 +11879,7 @@ grokdeclarator (const cp_declarator *declarator,
/* If this is declaring a typedef name, return a TYPE_DECL. */
if (typedef_p && decl_context != TYPENAME)
{
+ bool alias_p = decl_spec_seq_has_spec_p (declspecs, ds_alias);
tree decl;
/* This declaration:
@@ -11901,7 +11902,12 @@ grokdeclarator (const cp_declarator *declarator,
if (type_uses_auto (type))
{
- error ("typedef declared %<auto%>");
+ if (alias_p)
+ error_at (declspecs->locations[ds_alias],
+ "%<auto%> not allowed in alias declaration");
+ else
+ error_at (declspecs->locations[ds_typedef],
+ "typedef declared %<auto%>");
type = error_mark_node;
}
@@ -11961,7 +11967,7 @@ grokdeclarator (const cp_declarator *declarator,
inlinep, friendp, raises != NULL_TREE,
declspecs->locations);
- if (decl_spec_seq_has_spec_p (declspecs, ds_alias))
+ if (alias_p)
/* Acknowledge that this was written:
`using analias = atype;'. */
TYPE_DECL_ALIAS_P (decl) = 1;
Index: pt.c
===================================================================
--- pt.c (revision 264687)
+++ pt.c (working copy)
@@ -7776,7 +7776,7 @@ convert_template_argument (tree parm,
tree val;
int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
- if (parm == error_mark_node)
+ if (parm == error_mark_node || error_operand_p (arg))
return error_mark_node;
/* Trivially convert placeholders. */
More information about the Gcc-patches
mailing list