--- gcc/gimplify.c.jj	2021-09-14 10:36:41.351390039 +0200
+++ gcc/gimplify.c	2021-09-17 15:34:34.983711878 +0200
@@ -7369,6 +7369,18 @@ omp_default_clause (struct gimplify_omp_
     default_kind = kind;
   else if (VAR_P (decl) && TREE_STATIC (decl) && DECL_IN_CONSTANT_POOL (decl))
     default_kind = OMP_CLAUSE_DEFAULT_SHARED;
+  /* For C/C++ default({,first}private), variables with static storage duration
+     declared in a namespace or global scope and referenced in construct
+     must be explicitly specified, i.e. acts as default(none).  */
+  else if ((default_kind == OMP_CLAUSE_DEFAULT_PRIVATE
+	    || default_kind == OMP_CLAUSE_DEFAULT_FIRSTPRIVATE)
+	   && VAR_P (decl)
+	   && is_global_var (decl)
+	   && (DECL_FILE_SCOPE_P (decl)
+	       || (DECL_CONTEXT (decl)
+		   && TREE_CODE (DECL_CONTEXT (decl)) == NAMESPACE_DECL))
+	   && !lang_GNU_Fortran ())
+    default_kind = OMP_CLAUSE_DEFAULT_NONE;
 
   switch (default_kind)
     {
--- gcc/c/c-parser.c.jj	2021-09-17 11:28:07.601834144 +0200
+++ gcc/c/c-parser.c	2021-09-17 14:20:15.942866085 +0200
@@ -13420,6 +13420,9 @@ c_parser_omp_clause_copyprivate (c_parse
 /* OpenMP 2.5:
    default ( none | shared )
 
+   OpenMP 5.1:
+   default ( private | firstprivate )
+
    OpenACC:
    default ( none | present ) */
 
@@ -13446,9 +13449,24 @@ c_parser_omp_clause_default (c_parser *p
 	  break;
 
 	case 'p':
-	  if (strcmp ("present", p) != 0 || !is_oacc)
+	  if (is_oacc)
+	    {
+	      if (strcmp ("present", p) != 0)
+		goto invalid_kind;
+	      kind = OMP_CLAUSE_DEFAULT_PRESENT;
+	    }
+	  else
+	    {
+	      if (strcmp ("private", p) != 0)
+		goto invalid_kind;
+	      kind = OMP_CLAUSE_DEFAULT_PRIVATE;
+	    }
+	  break;
+
+	case 'f':
+	  if (strcmp ("firstprivate", p) != 0 || is_oacc)
 	    goto invalid_kind;
-	  kind = OMP_CLAUSE_DEFAULT_PRESENT;
+	  kind = OMP_CLAUSE_DEFAULT_FIRSTPRIVATE;
 	  break;
 
 	case 's':
@@ -13469,7 +13487,8 @@ c_parser_omp_clause_default (c_parser *p
       if (is_oacc)
 	c_parser_error (parser, "expected %<none%> or %<present%>");
       else
-	c_parser_error (parser, "expected %<none%> or %<shared%>");
+	c_parser_error (parser, "expected %<none%>, %<shared%>, "
+				"%<private%> or %<firstprivate%>");
     }
   parens.skip_until_found_close (parser);
 
--- gcc/cp/parser.c.jj	2021-09-17 11:28:07.606834074 +0200
+++ gcc/cp/parser.c	2021-09-17 15:44:33.665372845 +0200
@@ -36951,6 +36951,9 @@ cp_parser_omp_clause_collapse (cp_parser
 /* OpenMP 2.5:
    default ( none | shared )
 
+   OpenMP 5.1:
+   default ( private | firstprivate )
+
    OpenACC:
    default ( none | present ) */
 
@@ -36964,7 +36967,12 @@ cp_parser_omp_clause_default (cp_parser
   matching_parens parens;
   if (!parens.require_open (parser))
     return list;
-  if (cp_lexer_next_token_is (parser->lexer, CPP_NAME))
+  if (!is_oacc && cp_lexer_next_token_is_keyword (parser->lexer, RID_PRIVATE))
+    {
+      kind = OMP_CLAUSE_DEFAULT_PRIVATE;
+      cp_lexer_consume_token (parser->lexer);
+    }
+  else if (cp_lexer_next_token_is (parser->lexer, CPP_NAME))
     {
       tree id = cp_lexer_peek_token (parser->lexer)->u.value;
       const char *p = IDENTIFIER_POINTER (id);
@@ -36983,6 +36991,12 @@ cp_parser_omp_clause_default (cp_parser
 	  kind = OMP_CLAUSE_DEFAULT_PRESENT;
 	  break;
 
+	case 'f':
+	  if (strcmp ("firstprivate", p) != 0 || is_oacc)
+	    goto invalid_kind;
+	  kind = OMP_CLAUSE_DEFAULT_FIRSTPRIVATE;
+	  break;
+
 	case 's':
 	  if (strcmp ("shared", p) != 0 || is_oacc)
 	    goto invalid_kind;
@@ -37001,7 +37015,8 @@ cp_parser_omp_clause_default (cp_parser
       if (is_oacc)
 	cp_parser_error (parser, "expected %<none%> or %<present%>");
       else
-	cp_parser_error (parser, "expected %<none%> or %<shared%>");
+	cp_parser_error (parser, "expected %<none%>, %<shared%>, "
+				 "%<private%> or %<firstprivate%>");
     }
 
   if (kind == OMP_CLAUSE_DEFAULT_UNSPECIFIED
--- gcc/cp/cp-gimplify.c.jj	2021-08-19 11:42:27.308423193 +0200
+++ gcc/cp/cp-gimplify.c	2021-09-17 16:23:59.773400531 +0200
@@ -2060,6 +2060,7 @@ cxx_omp_finish_clause (tree c, gimple_se
   bool make_shared = false;
 
   if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_FIRSTPRIVATE
+      && OMP_CLAUSE_CODE (c) != OMP_CLAUSE_PRIVATE
       && (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_LASTPRIVATE
 	  || !OMP_CLAUSE_LASTPRIVATE_LOOP_IV (c)))
     return;
@@ -2080,9 +2081,10 @@ cxx_omp_finish_clause (tree c, gimple_se
      Save the results, because later we won't be in the right context
      for making these queries.  */
   bool first = OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE;
+  bool last = OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE;
   if (!make_shared
       && CLASS_TYPE_P (inner_type)
-      && cxx_omp_create_clause_info (c, inner_type, !first, first, !first,
+      && cxx_omp_create_clause_info (c, inner_type, !first, first, last,
 				     true))
     make_shared = true;
 
--- gcc/testsuite/c-c++-common/gomp/default-2.c.jj	2021-09-17 15:08:21.372642146 +0200
+++ gcc/testsuite/c-c++-common/gomp/default-2.c	2021-09-17 16:00:47.658804547 +0200
@@ -0,0 +1,67 @@
+int x;
+extern int z;
+
+void
+foo (void)
+{
+  int y = 0, i;
+  static int w;
+  #pragma omp task default(firstprivate)	/* { dg-message "note: enclosing 'task'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'task'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'task'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'task'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'task'" } */
+  }
+  #pragma omp taskloop default(firstprivate)	/* { dg-message "note: enclosing 'taskloop'" } */
+  for (i = 0; i < 64; i++)
+    {
+      y++;	/* { dg-bogus "'y' not specified in enclosing 'taskloop'" } */
+      w++;	/* { dg-bogus "'w' not specified in enclosing 'taskloop'" } */
+      x++;	/* { dg-error "'x' not specified in enclosing 'taskloop'" } */
+      z++;	/* { dg-error "'z' not specified in enclosing 'taskloop'" } */
+    }
+  #pragma omp teams default(firstprivate)	/* { dg-message "note: enclosing 'teams'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'teams'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'teams'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'teams'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'teams'" } */
+  }
+  #pragma omp parallel default(firstprivate)	/* { dg-message "note: enclosing 'parallel'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'parallel'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'parallel'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'parallel'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'parallel'" } */
+  }
+  #pragma omp task default(private)	/* { dg-message "note: enclosing 'task'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'task'" } */
+    w = 1;	/* { dg-bogus "'w' not specified in enclosing 'task'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'task'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'task'" } */
+  }
+  #pragma omp taskloop default(private)	/* { dg-message "note: enclosing 'taskloop'" } */
+  for (i = 0; i < 64; i++)
+    {
+      y = 1;	/* { dg-bogus "'y' not specified in enclosing 'taskloop'" } */
+      w = 1;	/* { dg-bogus "'w' not specified in enclosing 'taskloop'" } */
+      x++;	/* { dg-error "'x' not specified in enclosing 'taskloop'" } */
+      z++;	/* { dg-error "'z' not specified in enclosing 'taskloop'" } */
+    }
+  #pragma omp teams default(private)	/* { dg-message "note: enclosing 'teams'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'teams'" } */
+    w = 1;	/* { dg-bogus "'w' not specified in enclosing 'teams'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'teams'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'teams'" } */
+  }
+  #pragma omp parallel default(private)	/* { dg-message "note: enclosing 'parallel'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'parallel'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'parallel'" } */
+    x++;	/* { dg-error "'x' not specified in enclosing 'parallel'" } */
+    z++;	/* { dg-error "'z' not specified in enclosing 'parallel'" } */
+  }
+}
--- gcc/testsuite/c-c++-common/gomp/default-3.c.jj	2021-09-17 15:15:35.102596355 +0200
+++ gcc/testsuite/c-c++-common/gomp/default-3.c	2021-09-17 15:15:30.164665184 +0200
@@ -0,0 +1,14 @@
+void
+foo (void)
+{
+  int i;
+  #pragma omp task default(copyprivate)	/* { dg-error "expected 'none', 'shared', 'private' or 'firstprivate' before 'copyprivate'" } */
+  ;
+  #pragma omp taskloop default(copyprivate)	/* { dg-error "expected 'none', 'shared', 'private' or 'firstprivate' before 'copyprivate'" } */
+  for (i = 0; i < 64; i++)
+    ;
+  #pragma omp teams default(copyprivate)	/* { dg-error "expected 'none', 'shared', 'private' or 'firstprivate' before 'copyprivate'" } */
+  ;
+  #pragma omp parallel default(copyprivate)	/* { dg-error "expected 'none', 'shared', 'private' or 'firstprivate' before 'copyprivate'" } */
+  ;
+}
--- gcc/testsuite/g++.dg/gomp/default-1.C.jj	2021-09-17 15:48:54.737736963 +0200
+++ gcc/testsuite/g++.dg/gomp/default-1.C	2021-09-17 15:59:24.339965798 +0200
@@ -0,0 +1,112 @@
+namespace N
+{
+  int x;
+  extern int z;
+}
+
+struct S
+{
+  static int s;
+};
+
+#if __cpp_variable_templates >= 201304
+template <int N>
+int t = N;
+#endif
+
+void
+foo (void)
+{
+  int y = 0, i;
+  static int w;
+  #pragma omp task default(firstprivate)	/* { dg-message "note: enclosing 'task'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'task'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'task'" } */
+    S::s++;	/* { dg-bogus "'S::s' not specified in enclosing 'task'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'task'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'task'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'task'" "" { target c++14 } } */
+#endif
+  }
+  #pragma omp taskloop default(firstprivate)	/* { dg-message "note: enclosing 'taskloop'" } */
+  for (i = 0; i < 64; i++)
+    {
+      y++;	/* { dg-bogus "'y' not specified in enclosing 'taskloop'" } */
+      w++;	/* { dg-bogus "'w' not specified in enclosing 'taskloop'" } */
+      S::s++;	/* { dg-bogus "'S::s' not specified in enclosing 'taskloop'" } */
+      N::x++;	/* { dg-error "'x' not specified in enclosing 'taskloop'" } */
+      N::z++;	/* { dg-error "'z' not specified in enclosing 'taskloop'" } */
+#if __cpp_variable_templates >= 201304
+      t<5>++;	/* { dg-error "'t' not specified in enclosing 'taskloop'" "" { target c++14 } } */
+#endif
+    }
+  #pragma omp teams default(firstprivate)	/* { dg-message "note: enclosing 'teams'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'teams'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'teams'" } */
+    S::s++;	/* { dg-bogus "'S::s' not specified in enclosing 'teams'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'teams'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'teams'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'teams'" "" { target c++14 } } */
+#endif
+  }
+  #pragma omp parallel default(firstprivate)	/* { dg-message "note: enclosing 'parallel'" } */
+  {
+    y++;	/* { dg-bogus "'y' not specified in enclosing 'parallel'" } */
+    w++;	/* { dg-bogus "'w' not specified in enclosing 'parallel'" } */
+    S::s++;	/* { dg-bogus "'S::s' not specified in enclosing 'parallel'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'parallel'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'parallel'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'parallel'" "" { target c++14 } } */
+#endif
+  }
+  #pragma omp task default(private)	/* { dg-message "note: enclosing 'task'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'task'" } */
+    w = 1;	/* { dg-bogus "'w' not specified in enclosing 'task'" } */
+    S::s = 1;	/* { dg-bogus "'S::s' not specified in enclosing 'task'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'task'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'task'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'task'" "" { target c++14 } } */
+#endif
+  }
+  #pragma omp taskloop default(private)	/* { dg-message "note: enclosing 'taskloop'" } */
+  for (i = 0; i < 64; i++)
+    {
+      y = 1;	/* { dg-bogus "'y' not specified in enclosing 'taskloop'" } */
+      w = 1;	/* { dg-bogus "'w' not specified in enclosing 'taskloop'" } */
+      S::s = 1;	/* { dg-bogus "'S::s' not specified in enclosing 'taskloop'" } */
+      N::x++;	/* { dg-error "'x' not specified in enclosing 'taskloop'" } */
+      N::z++;	/* { dg-error "'z' not specified in enclosing 'taskloop'" } */
+#if __cpp_variable_templates >= 201304
+      t<5>++;	/* { dg-error "'t' not specified in enclosing 'taskloop'" "" { target c++14 } } */
+#endif
+    }
+  #pragma omp teams default(private)	/* { dg-message "note: enclosing 'teams'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'teams'" } */
+    w = 1;	/* { dg-bogus "'w' not specified in enclosing 'teams'" } */
+    S::s = 1;	/* { dg-bogus "'S::s' not specified in enclosing 'teams'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'teams'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'teams'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'teams'" "" { target c++14 } } */
+#endif
+  }
+  #pragma omp parallel default(private)	/* { dg-message "note: enclosing 'parallel'" } */
+  {
+    y = 1;	/* { dg-bogus "'y' not specified in enclosing 'parallel'" } */
+    w = 1;	/* { dg-bogus "'w' not specified in enclosing 'parallel'" } */
+    S::s = 1;	/* { dg-bogus "'S::s' not specified in enclosing 'parallel'" } */
+    N::x++;	/* { dg-error "'x' not specified in enclosing 'parallel'" } */
+    N::z++;	/* { dg-error "'z' not specified in enclosing 'parallel'" } */
+#if __cpp_variable_templates >= 201304
+    t<5>++;	/* { dg-error "'t' not specified in enclosing 'parallel'" "" { target c++14 } } */
+#endif
+  }
+}
--- libgomp/testsuite/libgomp.c++/default-1.C.jj	2021-09-17 16:07:13.222430760 +0200
+++ libgomp/testsuite/libgomp.c++/default-1.C	2021-09-17 16:25:31.411123142 +0200
@@ -0,0 +1,29 @@
+#include <omp.h>
+#include <stdlib.h>
+
+struct S { S () : s (42) {} S (const S &x) : s (x.s) {}; ~S () {} int s; };
+
+int
+main ()
+{
+  S s;
+  s.s = 113;
+  #pragma omp parallel num_threads(4) default(firstprivate)
+  {
+    if (s.s != 113)
+      abort ();
+    s.s = omp_get_thread_num ();
+    #pragma omp barrier
+    if (s.s != omp_get_thread_num ())
+      abort ();
+  }
+  #pragma omp parallel num_threads(4) default(private)
+  {
+    if (s.s != 42)
+      abort ();
+    s.s = omp_get_thread_num () + 13;
+    #pragma omp barrier
+    if (s.s != omp_get_thread_num () + 13)
+      abort ();
+  }
+}
--- libgomp/testsuite/libgomp.c-c++-common/default-1.c.jj	2021-09-17 16:04:30.546698051 +0200
+++ libgomp/testsuite/libgomp.c-c++-common/default-1.c	2021-09-17 16:04:23.713793285 +0200
@@ -0,0 +1,25 @@
+#include <omp.h>
+#include <stdlib.h>
+
+int
+main ()
+{
+  int v = 42;
+  #pragma omp parallel num_threads(4) default(firstprivate)
+  {
+    if (v != 42)
+      abort ();
+    v = omp_get_thread_num ();
+    #pragma omp barrier
+    if (v != omp_get_thread_num ())
+      abort ();
+  }
+  #pragma omp parallel num_threads(4) default(private)
+  {
+    v = omp_get_thread_num () + 13;
+    #pragma omp barrier
+    if (v != omp_get_thread_num () + 13)
+      abort ();
+  }
+  return 0;
+}
--- libgomp/libgomp.texi.jj	2021-09-17 12:33:32.557050348 +0200
+++ libgomp/libgomp.texi	2021-09-17 16:08:14.417577856 +0200
@@ -305,7 +305,7 @@ The OpenMP 4.5 specification is fully su
 @item @code{seq_cst} clause on a @code{flush} construct @tab Y @tab
 @item @code{inoutset} argument to the @code{depend} clause @tab N @tab
 @item @code{private} and @code{firstprivate} argument to @code{default}
-      clause in C and C++ @tab N @tab
+      clause in C and C++ @tab Y @tab
 @item @code{present} argument to @code{defaultmap} clause @tab N @tab
 @item @code{omp_set_num_teams}, @code{omp_set_teams_thread_limit},
       @code{omp_get_max_teams}, @code{omp_get_teams_thread_limit} runtime
