2021-10-11  Jakub Jelinek  <jakub@redhat.com>

	PR c++/102642
	* name-lookup.c (push_local_extern_decl_alias): Don't call
	set_decl_tls_model on error_mark_node.
	* parser.c (cp_parser_omp_declare_target): Likewise.

	* g++.dg/tls/pr102642.C: New test.

--- gcc/cp/name-lookup.c.jj	2021-10-01 10:30:07.674588541 +0200
+++ gcc/cp/name-lookup.c	2021-10-11 12:43:39.261051228 +0200
@@ -3474,7 +3474,9 @@ push_local_extern_decl_alias (tree decl)
 	  push_nested_namespace (ns);
 	  alias = do_pushdecl (alias, /* hiding= */true);
 	  pop_nested_namespace (ns);
-	  if (VAR_P (decl) && CP_DECL_THREAD_LOCAL_P (decl))
+	  if (VAR_P (decl)
+	      && CP_DECL_THREAD_LOCAL_P (decl)
+	      && alias != error_mark_node)
 	    set_decl_tls_model (alias, DECL_TLS_MODEL (decl));
 	}
     }
--- gcc/cp/parser.c.jj	2021-10-09 10:14:24.043098112 +0200
+++ gcc/cp/parser.c	2021-10-11 12:47:21.220874667 +0200
@@ -45665,7 +45666,8 @@ cp_parser_omp_declare_target (cp_parser
       if (VAR_OR_FUNCTION_DECL_P (t)
 	  && DECL_LOCAL_DECL_P (t)
 	  && DECL_LANG_SPECIFIC (t)
-	  && DECL_LOCAL_DECL_ALIAS (t))
+	  && DECL_LOCAL_DECL_ALIAS (t)
+	  && DECL_LOCAL_DECL_ALIAS (t) != error_mark_node)
 	handle_omp_declare_target_clause (c, DECL_LOCAL_DECL_ALIAS (t),
 					  device_type);
     }
--- gcc/testsuite/g++.dg/tls/pr102642.C.jj	2021-10-11 13:00:35.889503002 +0200
+++ gcc/testsuite/g++.dg/tls/pr102642.C	2021-10-11 13:00:20.388724721 +0200
@@ -0,0 +1,10 @@
+// PR c++/102642
+// { dg-do compile { target c++11 } }
+
+thread_local int *z;		// { dg-message "previous declaration" }
+
+void
+foo ()
+{
+  extern thread_local int z;	// { dg-error "conflicting declaration" }
+}