commit 51f060584f93ef1f3d9ad56b5f11c5b2cfe6fd7a
Author: Jason Merrill <jason@redhat.com>
Date: Fri Jun 5 18:48:24 2015 -0400
PR c++/66289
* cp-tree.h (TEMPLATE_DECL_COMPLEX_ALIAS_P): New.
* pt.c (push_template_decl_real): Set it.
(dependent_alias_template_spec_p): Use it.
(dependent_type_p_r): Use dependent_alias_template_spec_p.
(uses_all_template_parms_data, uses_all_template_parms_r)
(complex_alias_template_p): New.
(get_template_parm_index): Handle BOUND_TEMPLATE_TEMPLATE_PARM.
@@ -155,6 +155,7 @@ c-common.h, not after.
LABEL_DECL_CONTINUE (in LABEL_DECL)
2: DECL_THIS_EXTERN (in VAR_DECL or FUNCTION_DECL).
DECL_IMPLICIT_TYPEDEF_P (in a TYPE_DECL)
+ TEMPLATE_DECL_COMPLEX_ALIAS_P (in TEMPLATE_DECL)
3: DECL_IN_AGGR_P.
4: DECL_C_BIT_FIELD (in a FIELD_DECL)
DECL_ANON_UNION_VAR_P (in a VAR_DECL)
@@ -2732,6 +2733,10 @@ extern void decl_shadowed_for_var_insert (tree, tree);
#define TYPE_DECL_ALIAS_P(NODE) \
DECL_LANG_FLAG_6 (TYPE_DECL_CHECK (NODE))
+/* Nonzero for TEMPLATE_DECL means that it is a 'complex' alias template. */
+#define TEMPLATE_DECL_COMPLEX_ALIAS_P(NODE) \
+ DECL_LANG_FLAG_2 (TEMPLATE_DECL_CHECK (NODE))
+
/* Nonzero for a type which is an alias for another type; i.e, a type
which declaration was written 'using name-of-type =
another-type'. */
@@ -211,6 +211,7 @@ static tree template_parm_to_arg (tree t);
static tree current_template_args (void);
static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
static tree instantiate_alias_template (tree, tree, tsubst_flags_t);
+static bool complex_alias_template_p (const_tree tmpl);
/* Make the current scope suitable for access checking when we are
processing T. T can be FUNCTION_DECL for instantiated function
@@ -4420,6 +4421,7 @@ get_template_parm_index (tree parm)
|| TREE_CODE (parm) == TEMPLATE_DECL)
parm = TREE_TYPE (parm);
if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
+ || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM
|| TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
parm = TEMPLATE_TYPE_PARM_INDEX (parm);
gcc_assert (TREE_CODE (parm) == TEMPLATE_PARM_INDEX);
@@ -5096,6 +5098,11 @@ template arguments to %qD do not match original template %qD",
if (TREE_CODE (parm) == TEMPLATE_DECL)
DECL_CONTEXT (parm) = tmpl;
}
+
+ if (TREE_CODE (decl) == TYPE_DECL
+ && TYPE_DECL_ALIAS_P (decl)
+ && complex_alias_template_p (tmpl))
+ TEMPLATE_DECL_COMPLEX_ALIAS_P (tmpl) = true;
}
/* The DECL_TI_ARGS of DECL contains full set of arguments referring
@@ -5353,13 +5360,56 @@ alias_template_specialization_p (const_tree t)
return false;
}
-/* Return TRUE iff T is a specialization of an alias template with
+/* An alias template is complex from a SFINAE perspective if a template-id
+ using that alias can be ill-formed when the expansion is not, as with
+ the void_t template. We determine this by checking whether the
+ expansion for the alias template uses all its template parameters. */
+
+struct uses_all_template_parms_data
+{
+ int level;
+ bool *seen;
+};
+
+static int
+uses_all_template_parms_r (tree t, void *data_)
+{
+ struct uses_all_template_parms_data &data
+ = *(struct uses_all_template_parms_data*)data_;
+ tree idx = get_template_parm_index (t);
+
+ if (TEMPLATE_PARM_LEVEL (idx) == data.level)
+ data.seen[TEMPLATE_PARM_IDX (idx)] = true;
+ return 0;
+}
+
+static bool
+complex_alias_template_p (const_tree tmpl)
+{
+ struct uses_all_template_parms_data data;
+ tree pat = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
+ tree parms = DECL_TEMPLATE_PARMS (tmpl);
+ data.level = TMPL_PARMS_DEPTH (parms);
+ int len = TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS (parms));
+ data.seen = XALLOCAVEC (bool, len);
+ for (int i = 0; i < len; ++i)
+ data.seen[i] = false;
+
+ for_each_template_parm (pat, uses_all_template_parms_r, &data, NULL, true);
+ for (int i = 0; i < len; ++i)
+ if (!data.seen[i])
+ return true;
+ return false;
+}
+
+/* Return TRUE iff T is a specialization of a complex alias template with
dependent template-arguments. */
bool
dependent_alias_template_spec_p (const_tree t)
{
return (alias_template_specialization_p (t)
+ && TEMPLATE_DECL_COMPLEX_ALIAS_P (DECL_TI_TEMPLATE (TYPE_NAME (t)))
&& (any_dependent_template_arguments_p
(INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (t)))));
}
@@ -20951,9 +21001,7 @@ dependent_type_p_r (tree type)
return true;
/* For an alias template specialization, check the arguments both to the
class template and the alias template. */
- else if (alias_template_specialization_p (type)
- && (any_dependent_template_arguments_p
- (INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (type)))))
+ else if (dependent_alias_template_spec_p (type))
return true;
/* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
new file mode 100644
@@ -0,0 +1,13 @@
+// PR c++/66289
+// { dg-do compile { target c++11 } }
+
+template<typename T> struct A {};
+
+template<typename T> struct shared_ptr { };
+template<typename T> using APtr = shared_ptr<A<T>>;
+
+template<typename T> struct foo;
+template<typename T> struct foo<shared_ptr<T>> { };
+template<typename T> struct foo<APtr<T>> { };
+
+foo<shared_ptr<A<int>>> aa;