On Wed, Jan 04, 2017 at 04:24:55PM -0500, Jason Merrill wrote:
> On Mon, Jan 2, 2017 at 2:32 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> > if (TREE_CODE (type) == REFERENCE_TYPE)
> > {
> > - error ("in C++98 %q+D may not have reference type %qT "
> > - "because it is a member of a union", x, type);
> > - continue;
> > + if (cxx_dialect < cxx11)
> > + {
> > + error ("in C++98 %q+D may not have reference type %qT "
> > + "because it is a member of a union", x, type);
> > + continue;
> > + }
>
> I don't think we need the old error anymore; in C++98 mode we will
> have already complained about a static data member reference, so we
> can drop the above and just keep the below.
>
> > + else if (TREE_CODE (x) == FIELD_DECL)
> > + {
> > + error ("non-static data member %q+D in a union may not "
> > + "have reference type %qT", x, type);
> > + continue;
> > + }
Like this? Ok for trunk if bootstrap/regtest passes (just started them;
make check-c++-all didn't show regressions)?
2017-01-04 Jakub Jelinek <ja...@redhat.com>
PR c++/78890
* class.c (check_field_decls): Diagnose REFERENCE_TYPE fields in
unions even for C++11 and later.
* g++.dg/init/ref14.C: Expect error even in C++11 and later.
* g++.dg/init/union1.C: Likewise.
* g++.dg/cpp0x/union6.C: Expect errors.
* g++.dg/cpp0x/union8.C: New test.
* g++.dg/cpp0x/pr78890-1.C: New test.
* g++.dg/cpp0x/pr78890-2.C: New test.
--- gcc/cp/class.c.jj 2017-01-03 08:12:27.154511815 +0100
+++ gcc/cp/class.c 2017-01-04 22:41:32.669279309 +0100
@@ -3759,25 +3759,27 @@ check_field_decls (tree t, tree *access_
/* When this goes into scope, it will be a non-local reference. */
DECL_NONLOCAL (x) = 1;
- if (TREE_CODE (t) == UNION_TYPE
- && cxx_dialect < cxx11)
+ if (TREE_CODE (t) == UNION_TYPE)
{
/* [class.union] (C++98)
If a union contains a static data member, or a member of
reference type, the program is ill-formed.
- In C++11 this limitation doesn't exist anymore. */
- if (VAR_P (x))
+ In C++11 [class.union] says:
+ If a union contains a non-static data member of reference type
+ the program is ill-formed. */
+ if (VAR_P (x) && cxx_dialect < cxx11)
{
error ("in C++98 %q+D may not be static because it is "
"a member of a union", x);
continue;
}
- if (TREE_CODE (type) == REFERENCE_TYPE)
+ if (TREE_CODE (type) == REFERENCE_TYPE
+ && TREE_CODE (x) == FIELD_DECL)
{
- error ("in C++98 %q+D may not have reference type %qT "
- "because it is a member of a union", x, type);
+ error ("non-static data member %q+D in a union may not "
+ "have reference type %qT", x, type);
continue;
}
}
--- gcc/testsuite/g++.dg/init/ref14.C.jj 2017-01-03 08:12:26.878515378
+0100
+++ gcc/testsuite/g++.dg/init/ref14.C 2017-01-04 22:40:35.789996635 +0100
@@ -4,7 +4,7 @@
union A
{
- int &i; // { dg-error "may not have reference type" "" { target { ! c++11 }
} }
+ int &i; // { dg-error "may not have reference type" }
};
void foo()
--- gcc/testsuite/g++.dg/init/union1.C.jj 2017-01-03 08:12:26.862515585
+0100
+++ gcc/testsuite/g++.dg/init/union1.C 2017-01-04 22:40:35.789996635 +0100
@@ -1,5 +1,5 @@
// PR c++/14401
union U {
- int& i; // { dg-error "reference type" "" { target { ! c++11 } } }
+ int& i; // { dg-error "reference type" }
};
--- gcc/testsuite/g++.dg/cpp0x/pr78890-2.C.jj 2017-01-04 22:40:35.821996232
+0100
+++ gcc/testsuite/g++.dg/cpp0x/pr78890-2.C 2017-01-04 22:40:35.821996232
+0100
@@ -0,0 +1,44 @@
+// PR c++/78890
+// { dg-do compile { target c++11 } }
+
+template <typename T>
+int
+foo ()
+{
+ union {
+ int a;
+ int &b = a; // { dg-error "may not have reference
type" }
+ };
+ a = 1;
+ auto c = b + 1;
+ return c;
+}
+
+template <typename T>
+T
+bar ()
+{
+ union {
+ T a;
+ T &b = a; // { dg-error "may not have reference type" }
+ };
+ a = 1;
+ auto c = b + 1;
+ return c;
+}
+
+template <typename T, typename U>
+T baz()
+{
+ union {
+ T a;
+ U b = a; // { dg-error "may not have reference type" }
+ };
+ a = 1;
+ auto c = b + 1;
+ return c;
+}
+
+int a = foo<int> ();
+int b = bar<int> ();
+int c = baz<int, int &> ();
--- gcc/testsuite/g++.dg/cpp0x/union8.C.jj 2017-01-04 22:40:35.820996244
+0100
+++ gcc/testsuite/g++.dg/cpp0x/union8.C 2017-01-04 22:40:35.820996244 +0100
@@ -0,0 +1,26 @@
+// PR c++/78890
+// { dg-do compile { target c++11 } }
+
+union Test1 {
+ static int kConstant;
+};
+
+union Test2 {
+ static const int kConstant;
+};
+
+const int Test2::kConstant = 10;
+
+int k;
+
+union Test3 {
+ static int& kRef;
+};
+
+int& Test3::kRef = k;
+
+union Test4 {
+ static const int& kRef;
+};
+
+const int& Test4::kRef = 10;
--- gcc/testsuite/g++.dg/cpp0x/union6.C.jj 2017-01-03 08:12:26.926514759
+0100
+++ gcc/testsuite/g++.dg/cpp0x/union6.C 2017-01-04 22:40:35.820996244 +0100
@@ -12,9 +12,9 @@ union Test2 {
const int Test2::kConstant = 10;
union Test3 {
- int& kConstant;
+ int& kConstant; // { dg-error "may not have reference type" }
};
union Test4 {
- const int& kConstant = 10;
+ const int& kConstant = 10; // { dg-error "may not have reference type" }
};
--- gcc/testsuite/g++.dg/cpp0x/pr78890-1.C.jj 2017-01-04 22:40:35.820996244
+0100
+++ gcc/testsuite/g++.dg/cpp0x/pr78890-1.C 2017-01-04 22:40:35.820996244
+0100
@@ -0,0 +1,13 @@
+// PR c++/78890
+// { dg-do compile { target c++11 } }
+
+int
+main()
+{
+ union {
+ int a;
+ int &b = a; // { dg-error "may not have reference type" }
+ };
+ a = 1;
+ auto c = b + 1;
+}
Jakub
