Here, the problem ultimately seems to be that tsubst_copy_and_build,
when called with empty args as we do during non-dependent expression
folding, doesn't touch BASELINKs at all: it delegates to tsubst_copy
which then immediately exits early due to the empty args. This means
that the CAST_EXPR int(1) in the BASELINK A::condition<int(1)> never
gets folded (as part of folding of the overall CALL_EXPR), which later
causes us to crash when performing overload resolution of the rebuilt
CALL_EXPR (which is in terms of this still-templated BASELINK).
This doesn't happen when condition() is a namespace-scope function
because then condition<int(1)> is represented as a TEMPLATE_ID_EXPR
rather than a BASELINK, which does get handled directly from
tsubst_copy_and_build.
This patch fixes this issue by having tsubst_copy_and_build handle
BASELINK directly rather than delegating to tsubst_copy, so that it
processes BASELINKS even when args is empty.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?
gcc/cp/ChangeLog:
PR c++/95468
* pt.c (tsubst_copy_and_build) <case BASELINK>: New case, copied
over from tsubst_copy.
gcc/testsuite/ChangeLog:
PR c++/95468
* g++.dg/template/non-dependent15.C: New test.
---
gcc/cp/pt.c | 5 +++++
gcc/testsuite/g++.dg/template/non-dependent15.C | 12 ++++++++++++
2 files changed, 17 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/template/non-dependent15.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 5102bf02d0f..5b2f43dc5c1 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -19856,6 +19856,11 @@ tsubst_copy_and_build (tree t,
case SCOPE_REF:
RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
/*address_p=*/false));
+
+ case BASELINK:
+ return tsubst_baselink (t, current_nonlambda_class_type (),
+ args, complain, in_decl);
+
case ARRAY_REF:
op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
args, complain, in_decl);
diff --git a/gcc/testsuite/g++.dg/template/non-dependent15.C
b/gcc/testsuite/g++.dg/template/non-dependent15.C
new file mode 100644
index 00000000000..00dfe26d6ba
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/non-dependent15.C
@@ -0,0 +1,12 @@
+// PR c++/95468
+// { dg-do compile { target c++11 } }
+
+struct A {
+ template <int N>
+ static constexpr int condition() { return N; }
+};
+
+template <int> struct B {};
+
+template <class>
+using T = B<A::condition<int(1)>()>;
--
2.30.0.452.gfb7fa4a1fd
