[gcc r11-8629] c++: deleted after first declaration [PR101106]

[Jason Merrill <jason@gcc.gnu.org>]

https://gcc.gnu.org/g:2348a458e156641c5d4b0e998ae0d175196cfd51

commit r11-8629-g2348a458e156641c5d4b0e998ae0d175196cfd51
Author: Jason Merrill <jason@redhat.com>
Date:   Thu Jun 17 15:31:15 2021 -0400

    c++: deleted after first declaration [PR101106]
    
    An explicitly deleted function must be deleted on its first declaration.  We
    were diagnosing this error only with -Wpedantic, but always giving the
    "previous declaration" note.  For GCC 11, keep the -Wpedantic dependency,
    just make the note depend on the previous diagnostic.
    
            PR c++/101106
    
    gcc/cp/ChangeLog:
    
            * decl.c (duplicate_decls): Condition note on return value of pedwarn.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/cpp0x/deleted15.C: New test.

Diff:
---
 gcc/cp/decl.c                          | 9 ++++-----
 gcc/testsuite/g++.dg/cpp0x/deleted15.C | 6 ++++++
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index d2fc1c1d4a3..0ed15f53596 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2160,11 +2160,10 @@ duplicate_decls (tree newdecl, tree olddecl, bool hiding, bool was_hidden)
 	  if (DECL_DELETED_FN (newdecl))
 	    {
 	      auto_diagnostic_group d;
-	      pedwarn (newdecl_loc, OPT_Wpedantic,
-		       "deleted definition of %qD is not first declaration",
-		       newdecl);
-	      inform (olddecl_loc,
-		      "previous declaration of %qD", olddecl);
+	      if (pedwarn (newdecl_loc, OPT_Wpedantic, "deleted definition of "
+			   "%qD is not first declaration", newdecl))
+		inform (olddecl_loc,
+			"previous declaration of %qD", olddecl);
 	    }
 	  DECL_DELETED_FN (newdecl) |= DECL_DELETED_FN (olddecl);
 	}
diff --git a/gcc/testsuite/g++.dg/cpp0x/deleted15.C b/gcc/testsuite/g++.dg/cpp0x/deleted15.C
new file mode 100644
index 00000000000..ab1893d7e29
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/deleted15.C
@@ -0,0 +1,6 @@
+// PR c++/101106
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+int f();		// { dg-bogus "previous declaration" }
+int f() = delete;