r12-1989 fixed the testcase in the PR, but unfortunately the fix is
buggy:
1. It breaks the case where the common template between the
TEMPLATE_DECL t and ctx_parms is the innermost template (as in
concepts-memtmpl5.C below). This can be fixed by instead
passing the TREE_TYPE of ctmpl to common_enclosing_class when
ctmpl is a class template.
2. Even if that's fixed, the analogous case where the innermost
template is a partial specialization is still broken (as in
concepts-memtmpl5a.C below), because ctmpl is always the primary
template.
So this patch instead fixes the general problem in a a simpler way that
doesn't rely on ctx_parms at all: when looking for the template
parameters of a TEMPLATE_DECL that are shared with the current template
context, just walk its DECL_CONTEXT. As long as the template is not
overly general (e.g. we didn't pass it through most_general_template),
this should give us exactly what we want, since if a TEMPLATE_DECL can
be referred to from some template context then the template parameters
it uses must all be in-scope and represented in its DECL_CONTEXT. This
effectively makes us treat TEMPLATE_DECLs more similarly to other _DECLs
(whose DECL_CONTEXT we also walk).
Bootstrapped and regtested on x86_64-pc-linux-gnu, also tested on
cmcstl2 and range-v3, does this look OK for trunk/11?
PR c++/101247
gcc/cp/ChangeLog:
* pt.c (any_template_parm_r) <case TEMPLATE_DECL>: Just walk the
DECL_CONTEXT.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-memtmpl4.C: Uncomment the commented out
example, which we now handle correctly.
* g++.dg/cpp2a/concepts-memtmpl5.C: New test.
* g++.dg/cpp2a/concepts-memtmpl5a.C: New test.
---
gcc/cp/pt.c | 14 +++++---------
gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C | 2 +-
gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C | 11 +++++++++++
gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C | 15 +++++++++++++++
4 files changed, 32 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 7e56ccfc45f..dc0f0b7b58e 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10728,15 +10728,11 @@ any_template_parm_r (tree t, void *data)
break;
case TEMPLATE_DECL:
- {
- /* If T is a member template that shares template parameters with
- ctx_parms, we need to mark all those parameters for mapping. */
- if (tree ctmpl = TREE_TYPE (INNERMOST_TEMPLATE_PARMS (ftpi->ctx_parms)))
- if (tree com = common_enclosing_class (DECL_CONTEXT (t),
- DECL_CONTEXT (ctmpl)))
- if (tree ti = CLASSTYPE_TEMPLATE_INFO (com))
- WALK_SUBTREE (TI_ARGS (ti));
- }
+ /* If T is a member template that shares template parameters with
+ ctx_parms, we need to mark all those parameters for mapping.
+ To that end, it should suffice to just walk the DECL_CONTEXT of
+ the template (assuming the template is not overly general). */
+ WALK_SUBTREE (DECL_CONTEXT (t));
break;
case LAMBDA_EXPR:
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C
index 625149e5025..f990ae17859 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C
@@ -24,5 +24,5 @@ int main()
{
A<void>::B::f(0);
A<void>::C<int>::f(0);
- // A<void>::C<int>::g();
+ A<void>::C<int>::g();
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C
new file mode 100644
index 00000000000..3c83bb88485
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C
@@ -0,0 +1,11 @@
+// PR c++/101247
+// { dg-do compile { target concepts } }
+
+template<class T, class U> struct A {
+ template<class> static constexpr bool d = true;
+ static void g() requires d<U>;
+};
+
+int main() {
+ A<int, char>::g();
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C
new file mode 100644
index 00000000000..458f1cdf856
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C
@@ -0,0 +1,15 @@
+// PR c++/101247
+// { dg-do compile { target concepts } }
+// A variant of concepts-memtmpl5.C that uses a partial specialization
+// of A instead of the primary template.
+
+template<class, class> struct A;
+
+template<class T, class U> requires true struct A<T, U> {
+ template<class V> static constexpr bool d = true;
+ static void g() requires d<U>;
+};
+
+int main() {
+ A<int, char>::g();
+}
--
2.32.0.93.g670b81a890
