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C++ PATCH for core 1612 (lambda and anonymous union)
- From: Jason Merrill <jason at redhat dot com>
- To: gcc-patches List <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 22 Apr 2013 14:52:19 -0400
- Subject: C++ PATCH for core 1612 (lambda and anonymous union)
When a lambda names a member of an anonymous union, it's not clear
whether it's intended to capture the union as a whole or the member. So
we decided it should be ill-formed.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 37272f53baa15670141fcbf02a3f8219edb3827a
Author: Jason Merrill <jason@redhat.com>
Date: Tue Apr 16 13:07:00 2013 +0100
Core 1612
* semantics.c (finish_id_expression): Reject capture of anonymous
union member.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 2784d79..391dc1e 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3105,6 +3105,12 @@ finish_id_expression (tree id_expression,
= decl_function_context (containing_function);
}
+ if (lambda_expr && TREE_CODE (decl) == VAR_DECL
+ && DECL_ANON_UNION_VAR_P (decl))
+ {
+ error ("cannot capture member %qD of anonymous union", decl);
+ return error_mark_node;
+ }
if (context == containing_function)
{
decl = add_default_capture (lambda_stack,
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-anon1.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-anon1.C
new file mode 100644
index 0000000..482193e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-anon1.C
@@ -0,0 +1,18 @@
+// DR 1612
+// { dg-require-effective-target c++11 }
+
+int main() {
+ static int result;
+ struct A { int x; };
+ struct B { int y; };
+ union {
+ A a; B b;
+ };
+ a.x = 1;
+ [=]() mutable {
+ a.x = 2; // { dg-error "anonymous union" }
+ result = b.y; // { dg-error "anonymous union" }
+ }();
+ if (result == 1) return 0;
+ throw 0;
+}