Hello,
In the example of the patch, the U in 'typename U::X r' should bind to
the template parameter U rather than the class member U.
I think the problem comes from parameter_of_template_p that compares
parameters by using pointer equality, rather than by using type
equivalence like compparms does.
As a result, binding_to_template_parms_of_scope_p and then
outer_binding (via binding_to_template_parms_of_scope_p) misses the
template parameter U and returns the class member U instead.
Fixed thus, tested on x86_64-unknown-linux-gnu against trunk.
OK for trunk when stage 1 opens?
gcc/cp/
PR c++/51641
* cp-tree.h (template_type_parameter_p): Declare ...
* pt.c (template_type_parameter_p): ... new function.
(parameter_of_template_p): Rely on type equivalence rather
than pointer equality to compare template parms.
gcc/testsuite/
PR c++/51641
* g++.dg/lookup/hidden-class17.C: New test.
---
gcc/cp/cp-tree.h | 1 +
gcc/cp/pt.c | 29 ++++++++++++++++++++++---
gcc/testsuite/g++.dg/lookup/hidden-class17.C | 22 +++++++++++++++++++
3 files changed, 48 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/lookup/hidden-class17.C
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index f27755e..972c600 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -5361,6 +5361,7 @@ extern bool parameter_of_template_p (tree,
tree);
extern void init_template_processing (void);
extern void print_template_statistics (void);
bool template_template_parameter_p (const_tree);
+bool template_type_parameter_p (const_tree);
extern bool primary_template_instantiation_p (const_tree);
extern tree get_primary_template_innermost_parameters (const_tree);
extern tree get_template_parms_at_level (tree, int);
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index e440be7..cb9554a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -2890,6 +2890,18 @@ template_template_parameter_p (const_tree parm)
return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
}
+/* Return true iff PARM is a DECL representing a type template
+ parameter. */
+
+bool
+template_type_parameter_p (const_tree parm)
+{
+ return (parm
+ && (TREE_CODE (parm) == TYPE_DECL
+ || TREE_CODE (parm) == TEMPLATE_DECL)
+ && DECL_TEMPLATE_PARM_P (parm));
+}
+
/* Return the template parameters of T if T is a
primary template instantiation, NULL otherwise. */
@@ -8160,10 +8172,19 @@ parameter_of_template_p (tree parm, tree templ)
if (p == error_mark_node)
continue;
- if (parm == p
- || (DECL_INITIAL (parm)
- && DECL_INITIAL (parm) == DECL_INITIAL (p)))
- return true;
+ if (template_type_parameter_p (parm))
+ {
+ if (same_type_p (TREE_TYPE (parm), TREE_TYPE (p)))
+ return true;
+ }
+ else
+ {
+ if (DECL_INITIAL (parm)
+ && DECL_INITIAL (p)
+ && same_type_p (TREE_TYPE (DECL_INITIAL (parm)),
+ TREE_TYPE (DECL_INITIAL (p))))
+ return true;
+ }
}
return false;
diff --git a/gcc/testsuite/g++.dg/lookup/hidden-class17.C
b/gcc/testsuite/g++.dg/lookup/hidden-class17.C
new file mode 100644
index 0000000..3d5ccec
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/hidden-class17.C
@@ -0,0 +1,22 @@
+// Origin PR c++/51641
+// { dg-do compile }
+
+struct A {
+ struct B { typedef int X; };
+};
+
+template<class B> struct C : A {
+ B::X q; // Ok: A::B.
+ struct U { typedef int X; };
+ template<class U>
+ struct D;
+};
+
+template<class B>
+template<class U>
+struct C<B>::D {
+ typename U::X r; // { dg-error "" }
+};
+
+C<int>::D<double> y;
+
--
1.7.6.5
--
Dodji
