[gcc r12-2872] openmp: Diagnose omp::directive/sequence on using-directive

[gcc r12-2872] openmp: Diagnose omp::directive/sequence on using-directive

[Jakub Jelinek]

https://gcc.gnu.org/g:c84f79e9e3f63e9ae447fd15dbd0a768cab3f643

commit r12-2872-gc84f79e9e3f63e9ae447fd15dbd0a768cab3f643
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Aug 12 09:10:46 2021 +0200

    openmp: Diagnose omp::directive/sequence on using-directive
    
    With the using-directive parsing changes, we now emit only a warning
    for [[omp::directive (...)]] on using-directive.  While that is right
    without -fopenmp/-fopenmp-simd, when OpenMP is enabled, that should
    be an error as OpenMP (is going to) disallow such attributes there
    as they do not appertain to a statement.
    
    2021-08-12  Jakub Jelinek  <jakub@redhat.com>
    
            * name-lookup.c (finish_using_directive): Diagnose omp::directive
            or omp::sequence attributes on using-directive.
    
            * g++.dg/gomp/attrs-11.C: Adjust expected diagnostics.

Diff:
---
 gcc/cp/name-lookup.c                 | 11 +++++++++++
 gcc/testsuite/g++.dg/gomp/attrs-11.C |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 1be5f3da6d5..8e9c61e1ee8 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -8560,6 +8560,7 @@ finish_using_directive (tree target, tree attribs)
   add_using_namespace (current_binding_level->using_directives,
 		       ORIGINAL_NAMESPACE (target));
 
+  bool diagnosed = false;
   if (attribs != error_mark_node)
     for (tree a = attribs; a; a = TREE_CHAIN (a))
       {
@@ -8572,6 +8573,16 @@ finish_using_directive (tree target, tree attribs)
 	      inform (DECL_SOURCE_LOCATION (target),
 		      "you can use an inline namespace instead");
 	  }
+	else if ((flag_openmp || flag_openmp_simd)
+		 && get_attribute_namespace (a) == omp_identifier
+		 && (is_attribute_p ("directive", name)
+		     || is_attribute_p ("sequence", name)))
+	  {
+	    if (!diagnosed)
+	      error ("%<omp::%E%> not allowed to be specified in this "
+		     "context", name);
+	    diagnosed = true;
+	  }
 	else
 	  warning (OPT_Wattributes, "%qD attribute directive ignored", name);
       }
diff --git a/gcc/testsuite/g++.dg/gomp/attrs-11.C b/gcc/testsuite/g++.dg/gomp/attrs-11.C
index a8e27b74df5..009bcb2d87f 100644
--- a/gcc/testsuite/g++.dg/gomp/attrs-11.C
+++ b/gcc/testsuite/g++.dg/gomp/attrs-11.C
@@ -11,7 +11,7 @@ foo ()
   [[omp::directive (parallel)]] __extension__ asm ("");		// { dg-error "expected" }
   __extension__ [[omp::directive (parallel)]] asm ("");		// { dg-error "expected" }
   [[omp::directive (parallel)]] namespace M = ::N;		// { dg-error "expected" }
-  [[omp::directive (parallel)]] using namespace N;		// { dg-bogus "expected" "" { xfail *-*-* } }
+  [[omp::directive (parallel)]] using namespace N;		// { dg-error "not allowed to be specified in this context" }
   [[omp::directive (parallel)]] using O::T;			// { dg-error "expected" }
   [[omp::directive (parallel)]] __label__ foo;			// { dg-error "expected" }
   [[omp::directive (parallel)]] static_assert (true, "");	// { dg-error "expected" }