On 10/1/21 10:26, Patrick Palka wrote:
On Fri, 1 Oct 2021, Jason Merrill wrote:
On 10/1/21 09:46, Patrick Palka wrote:
Here during partial ordering of the two partial specializations we end
up in unify with parm=arg=NONTYPE_ARGUMENT_PACK<V0, V1>, and crash shortly
thereafter because uses_template_parms calls potential_constant_expression
which doesn't handle NONTYPE_ARGUMENT_PACK.
This patch fixes this by checking dependent_template_arg_p instead of
uses_template_parms when parm==arg, which does handle NONTYPE_ARGUMENT_PACK.
We could also perhaps fix uses_template_parms / inst_dep_expr_p to better
handle NONTYPE_ARGUMENT_PACK,
Please.
Sounds good, like the following then? Passes light testing, bootstrap
and regtest on progress.
-- >8 --
PR c++/102547
gcc/cp/ChangeLog:
* pt.c (instantiation_dependent_expression_p): Sidestep checking
potential_constant_expression on NONTYPE_ARGUMENT_PACK.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/variadic-partial2.C: New test.
* g++.dg/cpp0x/variadic-partial2a.C: New test.
---
gcc/cp/pt.c | 4 +++-
.../g++.dg/cpp0x/variadic-partial2.C | 16 ++++++++++++++
.../g++.dg/cpp0x/variadic-partial2a.C | 22 +++++++++++++++++++
3 files changed, 41 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C
create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 1dcdffe322a..643204103c5 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -27705,7 +27705,9 @@ instantiation_dependent_expression_p (tree expression)
{
return (instantiation_dependent_uneval_expression_p (expression)
|| (processing_template_decl
- && potential_constant_expression (expression)
+ && expression != NULL_TREE
+ && (TREE_CODE (expression) == NONTYPE_ARGUMENT_PACK
+ || potential_constant_expression (expression))
I'd prefer to loop over the elements of the pack, either here or
(probably better) in potential_constant_expression.
&& value_dependent_expression_p (expression)));
}
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C
new file mode 100644
index 00000000000..df61f26a3c1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C
@@ -0,0 +1,16 @@
+// PR c++/102547
+// { dg-do compile { target c++11 } }
+
+template<int... Vs>
+struct vals { };
+
+template<class V, class T>
+struct vals_client { };
+
+template<int V0, int V1, class T>
+struct vals_client<vals<V0, V1>, T> { };
+
+template<int V0, int V1>
+struct vals_client<vals<V0, V1>, void> { };
+
+template struct vals_client<vals<1, 2>, void>; //- "sorry, unimplemented...,
ICE"
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C
b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C
new file mode 100644
index 00000000000..cc0ea488ad3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C
@@ -0,0 +1,22 @@
+// PR c++/102547
+// { dg-do compile { target c++11 } }
+// A version of variadic-partial2.C where the partial ordering is performed
+// on function templates instead of class templates.
+
+template<int... Vs>
+struct vals { };
+
+template<class V, class T>
+void f(V, T) { };
+
+template<int V0, int V1, class T>
+void f(vals<V0, V1>, T) { };
+
+template<int V0, int V1>
+void f(vals<V0, V1>, char) { };
+
+template void f(vals<1, 2>, char); //- "sorry, unimplemented..., ICE"
+
+int main() {
+ f(vals<1, 3>{}, 'a'); //- "sorry, unimplemented..., ICE"
+}
