On 2/4/21 6:10 PM, Marek Polacek wrote:
Here we ICE in finish_nonmember_using_decl -> lookup_using_decl ->
... -> find_namespace_slot because "name" is not an IDENTIFIER_NODE.
It is a BIT_NOT_EXPR because this broken test uses
using E::~E; // SCOPE::NAME
A using-decl can't refer to a destructor, and lookup_using_decl already
checks that in the class member case. But in C++17, we do the "enum
scope is the enclosing scope" block, and so scope gets set to ::, and
we go into the NAMESPACE_DECL block. In C++20 we don't do it, we go
to the ENUMERAL_TYPE block.
I resorted to hoisting the check along with a diagnostic tweak: we
don't want to print "::::~E names destructor".
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
OK.
gcc/cp/ChangeLog:
PR c++/96462
* name-lookup.c (lookup_using_decl): Hoist the destructor check.
gcc/testsuite/ChangeLog:
PR c++/96462
* g++.dg/cpp2a/using-enum-8.C: New test.
---
gcc/cp/name-lookup.c | 15 ++++++++-------
gcc/testsuite/g++.dg/cpp2a/using-enum-8.C | 5 +++++
2 files changed, 13 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/using-enum-8.C
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 52e4a630e25..1f4a7ac1d0c 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -5700,6 +5700,14 @@ lookup_using_decl (tree scope, name_lookup &lookup)
scope = ctx;
}
+ /* You cannot using-decl a destructor. */
+ if (TREE_CODE (lookup.name) == BIT_NOT_EXPR)
+ {
+ error ("%<%T%s%D%> names destructor", scope,
+ &"::"[scope == global_namespace ? 2 : 0], lookup.name);
+ return NULL_TREE;
+ }
+
if (TREE_CODE (scope) == NAMESPACE_DECL)
{
/* Naming a namespace member. */
@@ -5739,13 +5747,6 @@ lookup_using_decl (tree scope, name_lookup &lookup)
return NULL_TREE;
}
- /* You cannot using-decl a destructor. */
- if (TREE_CODE (lookup.name) == BIT_NOT_EXPR)
- {
- error ("%<%T::%D%> names destructor", scope, lookup.name);
- return NULL_TREE;
- }
-
/* Using T::T declares inheriting ctors, even if T is a typedef. */
if (lookup.name == TYPE_IDENTIFIER (npscope)
|| constructor_name_p (lookup.name, npscope))
diff --git a/gcc/testsuite/g++.dg/cpp2a/using-enum-8.C
b/gcc/testsuite/g++.dg/cpp2a/using-enum-8.C
new file mode 100644
index 00000000000..9a743a98399
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/using-enum-8.C
@@ -0,0 +1,5 @@
+// PR c++/96462
+// { dg-do compile { target c++11 } }
+
+enum E {};
+using E::~E; // { dg-error "names destructor" }
base-commit: ce5720447c69286599b96bae53ae854b1bbe41fa
