OpenMP: lvalue parsing for map/to/from clauses (C++)

This patch supports "lvalue" parsing (or "locator list item type" parsing)
for several OpenMP clause types for C++, as required for OpenMP 5.0
and above.

This version has been rebased -- some things have changed around
template handling recently, e.g. removal of build_non_dependent_expr and
tsubst_copy.  A new potential corner-case issue has shown up regarding
implicit mapping of references to pointer to pointers -- an interaction
with the post-review fixes/rework for the patch here:

  https://gcc.gnu.org/pipermail/gcc-patches/2023-November/638602.html

Which fixed the (new) tests baseptrs-[6789].C.  I've noted that for now in
the patch, and adjusted the baseptrs-[46].C tests slightly to accommodate.

2024-01-08  Julian Brown  <julian@codesourcery.com>

gcc/c-family/
	* c-common.h (c_omp_address_inspector): Remove static from get_origin
	and maybe_unconvert_ref methods.
	* c-omp.cc (c_omp_split_clauses): Support OMP_ARRAY_SECTION.
	(c_omp_address_inspector::map_supported_p): Handle OMP_ARRAY_SECTION.
	(c_omp_address_inspector::get_origin): Avoid dereferencing possibly
	NULL type when processing template decls.
	(c_omp_address_inspector::maybe_unconvert_ref): Likewise.

gcc/cp/
	* constexpr.cc (potential_consant_expression_1): Handle
	OMP_ARRAY_SECTION.
	* cp-tree.h (grok_omp_array_section, build_omp_array_section): Add
	prototypes.
	* decl2.cc (grok_omp_array_section): New function.
	* error.cc (dump_expr): Handle OMP_ARRAY_SECTION.
	* parser.cc (cp_parser_new): Initialize parser->omp_array_section_p.
	(cp_parser_statement_expr): Disallow array sections.
	(cp_parser_postfix_open_square_expression): Support OMP_ARRAY_SECTION
	parsing.
	(cp_parser_parenthesized_expression_list, cp_parser_lambda_expression,
	cp_parser_braced_list): Disallow array sections.
	(cp_parser_omp_var_list_no_open): Remove ALLOW_DEREF parameter, add
	MAP_LVALUE in its place.  Support generalised lvalue parsing for
	OpenMP map, to and from clauses.  Use OMP_ARRAY_SECTION
	code instead of TREE_LIST to represent OpenMP array sections.
	(cp_parser_omp_var_list): Remove ALLOW_DEREF parameter, add MAP_LVALUE.
	Pass to cp_parser_omp_var_list_no_open.
	(cp_parser_oacc_data_clause): Update call to cp_parser_omp_var_list.
	(cp_parser_omp_clause_map): Add sk_omp scope around
	cp_parser_omp_var_list_no_open call.
	* parser.h (cp_parser): Add omp_array_section_p field.
	* pt.cc (tsubst, tsubst_copy, tsubst_omp_clause_decl,
	tsubst_copy_and_build): Add OMP_ARRAY_SECTION support.
	* semantics.cc (handle_omp_array_sections_1, handle_omp_array_sections,
	cp_oacc_check_attachments, finish_omp_clauses): Use OMP_ARRAY_SECTION
	instead of TREE_LIST where appropriate.  Handle more types of map
	expression.
	* typeck.cc (build_omp_array_section): New function.

gcc/
	* gimplify.cc (gimplify_expr): Ensure OMP_ARRAY_SECTION has been
	processed out before gimplification.
	* tree-pretty-print.cc (dump_generic_node): Support OMP_ARRAY_SECTION.
	* tree.def (OMP_ARRAY_SECTION): New tree code.

gcc/testsuite/
	* c-c++-common/gomp/map-6.c: Update expected output.
	* c-c++-common/gomp/target-enter-data-1.c: Update scan test.
	* g++.dg/gomp/array-section-1.C: New test.
	* g++.dg/gomp/array-section-2.C: New test.
	* g++.dg/gomp/bad-array-section-1.C: New test.
	* g++.dg/gomp/bad-array-section-2.C: New test.
	* g++.dg/gomp/bad-array-section-3.C: New test.
	* g++.dg/gomp/bad-array-section-4.C: New test.
	* g++.dg/gomp/bad-array-section-5.C: New test.
	* g++.dg/gomp/bad-array-section-6.C: New test.
	* g++.dg/gomp/bad-array-section-7.C: New test.
	* g++.dg/gomp/bad-array-section-8.C: New test.
	* g++.dg/gomp/bad-array-section-9.C: New test.
	* g++.dg/gomp/bad-array-section-10.C: New test.
	* g++.dg/gomp/bad-array-section-11.C: New test.
	* g++.dg/gomp/has_device_addr-non-lvalue-1.C: New test.
	* g++.dg/gomp/pr67522.C: Update expected output.
	* g++.dg/gomp/ind-base-3.C: New test.
	* g++.dg/gomp/map-assignment-1.C: New test.
	* g++.dg/gomp/map-inc-1.C: New test.
	* g++.dg/gomp/map-lvalue-ref-1.C: New test.
	* g++.dg/gomp/map-ptrmem-1.C: New test.
	* g++.dg/gomp/map-ptrmem-2.C: New test.
	* g++.dg/gomp/map-static-cast-lvalue-1.C: New test.
	* g++.dg/gomp/map-ternary-1.C: New test.
	* g++.dg/gomp/member-array-2.C: New test.

libgomp/
	* testsuite/libgomp.c++/baseptrs-4.C: Remove commented-out cases that
	now work.
	* testsuite/libgomp.c++/baseptrs-6.C: New test.
	* testsuite/libgomp.c++/ind-base-1.C: New test.
	* testsuite/libgomp.c++/ind-base-2.C: New test.
	* testsuite/libgomp.c++/lvalue-tofrom-1.C: New test.
	* testsuite/libgomp.c++/lvalue-tofrom-2.C: New test.
	* testsuite/libgomp.c++/map-comma-1.C: New test.
	* testsuite/libgomp.c++/map-rvalue-ref-1.C: New test.
	* testsuite/libgomp.c++/struct-ref-1.C: New test.
	* testsuite/libgomp.c-c++-common/array-field-1.c: New test.
	* testsuite/libgomp.c-c++-common/array-of-struct-1.c: New test.
	* testsuite/libgomp.c-c++-common/array-of-struct-2.c: New test.

40 files changed, 1263 insertions, 53 deletions

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 3c2d75a..2d5f539 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1373,8 +1373,8 @@ public:
 
   bool map_supported_p ();
 
-  static tree get_origin (tree);
-  static tree maybe_unconvert_ref (tree);
+  tree get_origin (tree);
+  tree maybe_unconvert_ref (tree);
 
   bool maybe_zero_length_array_section (tree);
 
diff --git a/gcc/c-family/c-omp.cc b/gcc/c-family/c-omp.cc
index 5bceb9c..5117022 100644
--- a/gcc/c-family/c-omp.cc
+++ b/gcc/c-family/c-omp.cc
@@ -2830,6 +2830,9 @@ c_omp_split_clauses (location_t loc, enum tree_code code,
 		    }
 		  else if (TREE_CODE (OMP_CLAUSE_DECL (c)) == TREE_LIST)
 		    {
+		      /* TODO: This can go away once we transition all uses of
+			 TREE_LIST for representing OMP array sections to
+			 OMP_ARRAY_SECTION.  */
 		      tree t;
 		      for (t = OMP_CLAUSE_DECL (c);
 			   TREE_CODE (t) == TREE_LIST; t = TREE_CHAIN (t))
@@ -2838,6 +2841,17 @@ c_omp_split_clauses (location_t loc, enum tree_code code,
 			bitmap_clear_bit (&allocate_head, DECL_UID (t));
 		      break;
 		    }
+		  else if (TREE_CODE (OMP_CLAUSE_DECL (c)) == OMP_ARRAY_SECTION)
+		    {
+		      tree t;
+		      for (t = OMP_CLAUSE_DECL (c);
+			   TREE_CODE (t) == OMP_ARRAY_SECTION;
+			   t = TREE_OPERAND (t, 0))
+			;
+		      if (DECL_P (t))
+			bitmap_clear_bit (&allocate_head, DECL_UID (t));
+		      break;
+		    }
 		  /* FALLTHRU */
 		case OMP_CLAUSE_PRIVATE:
 		case OMP_CLAUSE_FIRSTPRIVATE:
@@ -3379,6 +3393,7 @@ c_omp_address_inspector::map_supported_p ()
 	 || TREE_CODE (t) == SAVE_EXPR
 	 || TREE_CODE (t) == POINTER_PLUS_EXPR
 	 || TREE_CODE (t) == NON_LVALUE_EXPR
+	 || TREE_CODE (t) == OMP_ARRAY_SECTION
 	 || TREE_CODE (t) == NOP_EXPR)
     if (TREE_CODE (t) == COMPOUND_EXPR)
       t = TREE_OPERAND (t, 1);
@@ -3408,7 +3423,8 @@ c_omp_address_inspector::get_origin (tree t)
       else if (TREE_CODE (t) == POINTER_PLUS_EXPR
 	       || TREE_CODE (t) == SAVE_EXPR)
 	t = TREE_OPERAND (t, 0);
-      else if (TREE_CODE (t) == INDIRECT_REF
+      else if (!processing_template_decl_p ()
+	       && TREE_CODE (t) == INDIRECT_REF
 	       && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == REFERENCE_TYPE)
 	t = TREE_OPERAND (t, 0);
       else
@@ -3425,7 +3441,10 @@ c_omp_address_inspector::get_origin (tree t)
 tree
 c_omp_address_inspector::maybe_unconvert_ref (tree t)
 {
-  if (TREE_CODE (t) == INDIRECT_REF
+  /* Be careful not to dereference the type if we're processing a
+     template decl, else it might be NULL.  */
+  if (!processing_template_decl_p ()
+      && TREE_CODE (t) == INDIRECT_REF
       && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == REFERENCE_TYPE)
     return TREE_OPERAND (t, 0);
 
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index e3f398b..37500b7 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -10105,6 +10105,7 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
     case OACC_ENTER_DATA:
     case OACC_EXIT_DATA:
     case OACC_UPDATE:
+    case OMP_ARRAY_SECTION:
       /* GCC internal stuff.  */
     case VA_ARG_EXPR:
     case TRANSACTION_EXPR:
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index e43effa..86084b5 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7069,6 +7069,7 @@ extern void grokclassfn				(tree, tree,
 						 enum overload_flags);
 extern tree grok_array_decl			(location_t, tree, tree,
 						 vec<tree, va_gc> **, tsubst_flags_t);
+extern tree grok_omp_array_section		(location_t, tree, tree, tree);
 extern tree delete_sanity			(location_t, tree, tree, bool,
 						 int, tsubst_flags_t);
 extern tree check_classfn			(tree, tree, tree);
@@ -8172,6 +8173,7 @@ inline tree build_x_binary_op (const op_location_t &loc,
 }
 extern tree build_x_array_ref			(location_t, tree, tree,
 						 tsubst_flags_t);
+extern tree build_omp_array_section		(location_t, tree, tree, tree);
 extern tree build_x_unary_op			(location_t,
 						 enum tree_code, cp_expr,
 						 tree, tsubst_flags_t);
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index fb99656..5ceed56 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -617,6 +617,43 @@ grok_array_decl (location_t loc, tree array_expr, tree index_exp,
   return expr;
 }
 
+/* Build an OMP_ARRAY_SECTION expression, handling usage in template
+   definitions, etc.  */
+
+tree
+grok_omp_array_section (location_t loc, tree array_expr, tree index,
+			tree length)
+{
+  tree orig_array_expr = array_expr;
+  tree orig_index = index;
+  tree orig_length = length;
+
+  if (error_operand_p (array_expr)
+      || error_operand_p (index)
+      || error_operand_p (length))
+    return error_mark_node;
+
+  if (processing_template_decl
+      && (type_dependent_expression_p (array_expr)
+	  || type_dependent_expression_p (index)
+	  || type_dependent_expression_p (length)))
+    return build_min_nt_loc (loc, OMP_ARRAY_SECTION, array_expr, index, length);
+
+  index = fold_non_dependent_expr (index);
+  length = fold_non_dependent_expr (length);
+
+  /* NOTE: We can pass through invalidly-typed index/length fields
+     here (e.g. if the user tries to use a floating-point index/length).
+     This is diagnosed later in semantics.cc:handle_omp_array_sections_1.  */
+
+  tree expr = build_omp_array_section (loc, array_expr, index, length);
+
+  if (processing_template_decl)
+    expr = build_min_non_dep (OMP_ARRAY_SECTION, expr, orig_array_expr,
+			      orig_index, orig_length);
+  return expr;
+}
+
 /* Given the cast expression EXP, checking out its validity.   Either return
    an error_mark_node if there was an unavoidable error, return a cast to
    void for trying to delete a pointer w/ the value 0, or return the
diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc
index 9100496..a384f62 100644
--- a/gcc/cp/error.cc
+++ b/gcc/cp/error.cc
@@ -2497,6 +2497,15 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
       pp_cxx_right_bracket (pp);
       break;
 
+    case OMP_ARRAY_SECTION:
+      dump_expr (pp, TREE_OPERAND (t, 0), flags);
+      pp_cxx_left_bracket (pp);
+      dump_expr (pp, TREE_OPERAND (t, 1), flags);
+      pp_colon (pp);
+      dump_expr (pp, TREE_OPERAND (t, 2), flags);
+      pp_cxx_right_bracket (pp);
+      break;
+
     case UNARY_PLUS_EXPR:
       dump_unary_op (pp, "+", t, flags);
       break;
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index bc1683b..706ed21 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -4459,6 +4459,9 @@ cp_parser_new (cp_lexer *lexer)
   parser->omp_declare_simd = NULL;
   parser->oacc_routine = NULL;
 
+  /* Disallow OpenMP array sections in expressions.  */
+  parser->omp_array_section_p = false;
+
   /* Not declaring an implicit function template.  */
   parser->auto_is_implicit_function_template_parm_p = false;
   parser->fully_implicit_function_template_p = false;
@@ -5462,6 +5465,7 @@ static cp_expr
 cp_parser_statement_expr (cp_parser *parser)
 {
   cp_token_position start = cp_parser_start_tentative_firewall (parser);
+  auto oas = make_temp_override (parser->omp_array_section_p, false);
 
   /* Consume the '('.  */
   location_t start_loc = cp_lexer_peek_token (parser->lexer)->location;
@@ -8299,6 +8303,7 @@ cp_parser_postfix_open_square_expression (cp_parser *parser,
   releasing_vec expression_list = NULL;
   location_t loc = cp_lexer_peek_token (parser->lexer)->location;
   bool saved_greater_than_is_operator_p;
+  bool saved_colon_corrects_to_scope_p;
 
   /* Consume the `[' token.  */
   cp_lexer_consume_token (parser->lexer);
@@ -8306,6 +8311,10 @@ cp_parser_postfix_open_square_expression (cp_parser *parser,
   saved_greater_than_is_operator_p = parser->greater_than_is_operator_p;
   parser->greater_than_is_operator_p = true;
 
+  saved_colon_corrects_to_scope_p = parser->colon_corrects_to_scope_p;
+  if (parser->omp_array_section_p)
+    parser->colon_corrects_to_scope_p = false;
+
   /* Parse the index expression.  */
   /* ??? For offsetof, there is a question of what to allow here.  If
      offsetof is not being used in an integral constant expression context,
@@ -8316,7 +8325,8 @@ cp_parser_postfix_open_square_expression (cp_parser *parser,
      constant expressions here.  */
   if (for_offsetof)
     index = cp_parser_constant_expression (parser);
-  else
+  else if (!parser->omp_array_section_p
+	   || cp_lexer_next_token_is_not (parser->lexer, CPP_COLON))
     {
       if (cxx_dialect >= cxx23
 	  && cp_lexer_next_token_is (parser->lexer, CPP_CLOSE_SQUARE))
@@ -8372,6 +8382,68 @@ cp_parser_postfix_open_square_expression (cp_parser *parser,
 
   parser->greater_than_is_operator_p = saved_greater_than_is_operator_p;
 
+  if (cxx_dialect >= cxx23
+      && parser->omp_array_section_p
+      && expression_list.get () != NULL
+      && vec_safe_length (expression_list) > 1)
+    {
+      error_at (loc, "cannot use multidimensional subscript in OpenMP array "
+		"section");
+      index = error_mark_node;
+    }
+  if (parser->omp_array_section_p
+      && cp_lexer_next_token_is (parser->lexer, CPP_COLON))
+    {
+      cp_lexer_consume_token (parser->lexer);
+      tree length = NULL_TREE;
+      if (cp_lexer_next_token_is_not (parser->lexer, CPP_CLOSE_SQUARE))
+	{
+	  if (cxx_dialect >= cxx23)
+	    {
+	      cp_expr expr
+		= cp_parser_parenthesized_expression_list_elt (parser,
+							       /*cast_p=*/
+							       false,
+							       /*allow_exp_p=*/
+							       true,
+							       /*non_cst_p=*/
+							       NULL);
+
+	      if (expr == error_mark_node)
+		length = error_mark_node;
+	      else
+		length = expr.get_value ();
+
+	      if (cp_lexer_next_token_is (parser->lexer, CPP_COMMA))
+		{
+		  error_at (loc, "cannot use multidimensional subscript in "
+			    "OpenMP array section");
+		  length = error_mark_node;
+		}
+	    }
+	  else
+	    length
+	      = cp_parser_expression (parser, NULL, /*cast_p=*/false,
+				      /*decltype_p=*/false,
+				      /*warn_comma_p=*/warn_comma_subscript);
+	}
+
+      parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p;
+
+      if (index == error_mark_node || length == error_mark_node)
+	{
+	  cp_parser_skip_to_closing_square_bracket (parser);
+	  return error_mark_node;
+	}
+      else
+	cp_parser_require (parser, CPP_CLOSE_SQUARE, RT_CLOSE_SQUARE);
+
+      return grok_omp_array_section (input_location, postfix_expression, index,
+				     length);
+    }
+
+  parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p;
+
   /* Look for the closing `]'.  */
   cp_parser_require (parser, CPP_CLOSE_SQUARE, RT_CLOSE_SQUARE);
 
@@ -8700,6 +8772,7 @@ cp_parser_parenthesized_expression_list (cp_parser* parser,
 {
   vec<tree, va_gc> *expression_list;
   bool saved_greater_than_is_operator_p;
+  bool saved_omp_array_section_p;
 
   /* Assume all the expressions will be constant.  */
   if (non_constant_p)
@@ -8717,6 +8790,9 @@ cp_parser_parenthesized_expression_list (cp_parser* parser,
     = parser->greater_than_is_operator_p;
   parser->greater_than_is_operator_p = true;
 
+  saved_omp_array_section_p = parser->omp_array_section_p;
+  parser->omp_array_section_p = false;
+
   cp_expr expr (NULL_TREE);
 
   /* Consume expressions until there are no more.  */
@@ -8783,12 +8859,14 @@ cp_parser_parenthesized_expression_list (cp_parser* parser,
 	{
 	  parser->greater_than_is_operator_p
 	    = saved_greater_than_is_operator_p;
+	  parser->omp_array_section_p = saved_omp_array_section_p;
 	  return NULL;
 	}
     }
 
   parser->greater_than_is_operator_p
     = saved_greater_than_is_operator_p;
+  parser->omp_array_section_p = saved_omp_array_section_p;
 
   return expression_list;
 }
@@ -11299,6 +11377,7 @@ cp_parser_lambda_expression (cp_parser* parser)
     cp_binding_level* implicit_template_scope = parser->implicit_template_scope;
     bool auto_is_implicit_function_template_parm_p
         = parser->auto_is_implicit_function_template_parm_p;
+    bool saved_omp_array_section_p = parser->omp_array_section_p;
 
     parser->num_template_parameter_lists = 0;
     parser->in_statement = 0;
@@ -11307,6 +11386,7 @@ cp_parser_lambda_expression (cp_parser* parser)
     parser->implicit_template_parms = 0;
     parser->implicit_template_scope = 0;
     parser->auto_is_implicit_function_template_parm_p = false;
+    parser->omp_array_section_p = false;
 
     /* The body of a lambda in a discarded statement is not discarded.  */
     bool discarded = in_discarded_stmt;
@@ -11357,6 +11437,7 @@ cp_parser_lambda_expression (cp_parser* parser)
     parser->implicit_template_scope = implicit_template_scope;
     parser->auto_is_implicit_function_template_parm_p
 	= auto_is_implicit_function_template_parm_p;
+    parser->omp_array_section_p = saved_omp_array_section_p;
   }
 
   /* This field is only used during parsing of the lambda.  */
@@ -25917,6 +25998,7 @@ cp_parser_braced_list (cp_parser *parser, bool *non_constant_p /*=nullptr*/)
 {
   tree initializer;
   location_t start_loc = cp_lexer_peek_token (parser->lexer)->location;
+  auto oas = make_temp_override (parser->omp_array_section_p, false);
 
   /* Consume the `{' token.  */
   matching_braces braces;
@@ -37862,7 +37944,7 @@ struct omp_dim
 static tree
 cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 				tree list, bool *colon,
-				bool allow_deref = false)
+				bool map_lvalue = false)
 {
   auto_vec<omp_dim> dims;
   bool array_section_p;
@@ -37879,6 +37961,104 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 
       if (kind == OMP_CLAUSE_DEPEND || kind == OMP_CLAUSE_AFFINITY)
 	cp_parser_parse_tentatively (parser);
+      /* This condition doesn't include OMP_CLAUSE_DEPEND or
+	 OMP_CLAUSE_AFFINITY since lvalue ("locator list") parsing for those is
+	 handled further down the function.  */
+      else if (map_lvalue
+	       && (kind == OMP_CLAUSE_MAP
+		   || kind == OMP_CLAUSE_TO
+		   || kind == OMP_CLAUSE_FROM))
+	{
+	  auto s = make_temp_override (parser->omp_array_section_p, true);
+	  token = cp_lexer_peek_token (parser->lexer);
+	  location_t loc = token->location;
+	  decl = cp_parser_assignment_expression (parser);
+
+	  /* This code rewrites a parsed expression containing various tree
+	     codes used to represent array accesses into a more uniform nest of
+	     OMP_ARRAY_SECTION nodes before it is processed by
+	     semantics.cc:handle_omp_array_sections_1.  It might be more
+	     efficient to move this logic to that function instead, analysing
+	     the parsed expression directly rather than this preprocessed
+	     form.  */
+	  dims.truncate (0);
+	  if (TREE_CODE (decl) == OMP_ARRAY_SECTION)
+	    {
+	      while (TREE_CODE (decl) == OMP_ARRAY_SECTION)
+		{
+		  tree low_bound = TREE_OPERAND (decl, 1);
+		  tree length = TREE_OPERAND (decl, 2);
+		  dims.safe_push (omp_dim (low_bound, length, loc, false));
+		  decl = TREE_OPERAND (decl, 0);
+		}
+
+	      while (TREE_CODE (decl) == ARRAY_REF
+		     || TREE_CODE (decl) == INDIRECT_REF
+		     || TREE_CODE (decl) == COMPOUND_EXPR)
+		{
+		  if (REFERENCE_REF_P (decl))
+		    break;
+
+		  if (TREE_CODE (decl) == COMPOUND_EXPR)
+		    {
+		      decl = TREE_OPERAND (decl, 1);
+		      STRIP_NOPS (decl);
+		    }
+		  else if (TREE_CODE (decl) == INDIRECT_REF)
+		    {
+		      dims.safe_push (omp_dim (integer_zero_node,
+					       integer_one_node, loc, true));
+		      decl = TREE_OPERAND (decl, 0);
+		    }
+		  else  /* ARRAY_REF. */
+		    {
+		      tree index = TREE_OPERAND (decl, 1);
+		      dims.safe_push (omp_dim (index, integer_one_node, loc,
+					       true));
+		      decl = TREE_OPERAND (decl, 0);
+		    }
+		}
+
+	      /* Bare references have their own special handling, so remove
+		 the explicit dereference added by convert_from_reference.  */
+	      if (REFERENCE_REF_P (decl))
+		decl = TREE_OPERAND (decl, 0);
+
+	      for (int i = dims.length () - 1; i >= 0; i--)
+		decl = grok_omp_array_section (loc, decl, dims[i].low_bound,
+					       dims[i].length);
+	    }
+	  else if (TREE_CODE (decl) == INDIRECT_REF)
+	    {
+	      bool ref_p = REFERENCE_REF_P (decl);
+
+	      /* If we have "*foo" and
+		 - it's an indirection of a reference, "unconvert" it, i.e.
+		   strip the indirection (to just "foo").
+		 - it's an indirection of a pointer, turn it into
+		   "foo[0:1]".  */
+	      decl = TREE_OPERAND (decl, 0);
+	      STRIP_NOPS (decl);
+
+	      if (!ref_p)
+		decl = grok_omp_array_section (loc, decl, integer_zero_node,
+					       integer_one_node);
+	    }
+	  else if (TREE_CODE (decl) == ARRAY_REF)
+	    {
+	      tree idx = TREE_OPERAND (decl, 1);
+
+	      decl = TREE_OPERAND (decl, 0);
+	      STRIP_NOPS (decl);
+
+	      decl = grok_omp_array_section (loc, decl, idx, integer_one_node);
+	    }
+	  else if (TREE_CODE (decl) == NON_LVALUE_EXPR
+		   || CONVERT_EXPR_P (decl))
+	    decl = TREE_OPERAND (decl, 0);
+
+	  goto build_clause;
+	}
       token = cp_lexer_peek_token (parser->lexer);
       if (kind != 0
 	  && cp_parser_is_keyword (token, RID_THIS))
@@ -37957,8 +38137,7 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 	    case OMP_CLAUSE_TO:
 	    start_component_ref:
 	      while (cp_lexer_next_token_is (parser->lexer, CPP_DOT)
-		     || (allow_deref
-			 && cp_lexer_next_token_is (parser->lexer, CPP_DEREF)))
+		     || cp_lexer_next_token_is (parser->lexer, CPP_DEREF))
 		{
 		  cpp_ttype ttype
 		    = cp_lexer_next_token_is (parser->lexer, CPP_DOT)
@@ -38044,9 +38223,7 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 		   || kind == OMP_CLAUSE_TO)
 		  && !array_section_p
 		  && (cp_lexer_next_token_is (parser->lexer, CPP_DOT)
-		      || (allow_deref
-			  && cp_lexer_next_token_is (parser->lexer,
-						     CPP_DEREF))))
+		      || cp_lexer_next_token_is (parser->lexer, CPP_DEREF)))
 		{
 		  for (unsigned i = 0; i < dims.length (); i++)
 		    {
@@ -38058,8 +38235,9 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 		}
 	      else
 		for (unsigned i = 0; i < dims.length (); i++)
-		  decl = tree_cons (dims[i].low_bound, dims[i].length, decl);
-
+		  decl = build_omp_array_section (input_location, decl,
+						  dims[i].low_bound,
+						  dims[i].length);
 	      break;
 	    default:
 	      break;
@@ -38080,6 +38258,7 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 		cp_parser_parse_definitely (parser);
 	    }
 
+	build_clause:
 	  tree u = build_omp_clause (token->location, kind);
 	  OMP_CLAUSE_DECL (u) = decl;
 	  OMP_CLAUSE_CHAIN (u) = list;
@@ -38129,7 +38308,7 @@ cp_parser_omp_var_list_no_open (cp_parser *parser, enum omp_clause_code kind,
 
 static tree
 cp_parser_omp_var_list (cp_parser *parser, enum omp_clause_code kind, tree list,
-			bool allow_deref = false)
+			bool map_lvalue = false)
 {
   if (parser->lexer->in_omp_decl_attribute)
     {
@@ -38148,7 +38327,7 @@ cp_parser_omp_var_list (cp_parser *parser, enum omp_clause_code kind, tree list,
 
   if (cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN))
     return cp_parser_omp_var_list_no_open (parser, kind, list, NULL,
-					   allow_deref);
+					   map_lvalue);
   return list;
 }
 
@@ -38217,7 +38396,7 @@ cp_parser_oacc_data_clause (cp_parser *parser, pragma_omp_clause c_kind,
       gcc_unreachable ();
     }
   tree nl, c;
-  nl = cp_parser_omp_var_list (parser, OMP_CLAUSE_MAP, list, true);
+  nl = cp_parser_omp_var_list (parser, OMP_CLAUSE_MAP, list, false);
 
   for (c = nl; c != list; c = OMP_CLAUSE_CHAIN (c))
     OMP_CLAUSE_SET_MAP_KIND (c, kind);
@@ -41157,8 +41336,13 @@ cp_parser_omp_clause_map (cp_parser *parser, tree list)
       cp_lexer_consume_token (parser->lexer);
     }
 
+  /* We introduce a scope here so that errors parsing e.g. "always", "close"
+     tokens do not propagate to later directives that might use them
+     legally.  */
+  begin_scope (sk_omp, NULL);
   nlist = cp_parser_omp_var_list_no_open (parser, OMP_CLAUSE_MAP, list,
 					  NULL, true);
+  finish_scope ();
 
   for (c = nlist; c != list; c = OMP_CLAUSE_CHAIN (c))
     OMP_CLAUSE_SET_MAP_KIND (c, kind);
diff --git a/gcc/cp/parser.h b/gcc/cp/parser.h
index 8a40d38..373e78f 100644
--- a/gcc/cp/parser.h
+++ b/gcc/cp/parser.h
@@ -412,6 +412,9 @@ struct GTY(()) cp_parser {
      appear.  */
   bool omp_attrs_forbidden_p;
 
+  /* TRUE if an OpenMP array section is allowed.  */
+  bool omp_array_section_p;
+
   /* Tracks the function's template parameter list when declaring a function
      using generic type parameters.  This is either a new chain in the case of a
      fully implicit function template or an extension of the function's existing
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index e38e7a7..7237bd3 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -16838,6 +16838,7 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
     case CALL_EXPR:
     case ARRAY_REF:
     case SCOPE_REF:
+    case OMP_ARRAY_SECTION:
       /* We should use one of the expression tsubsts for these codes.  */
       gcc_unreachable ();
 
@@ -17432,6 +17433,21 @@ tsubst_omp_clause_decl (tree decl, tree args, tsubst_flags_t complain,
 	= OMP_CLAUSE_DOACROSS_SINK_NEGATIVE (decl);
       return ret;
     }
+  else if (TREE_CODE (decl) == OMP_ARRAY_SECTION)
+    {
+      tree low_bound
+	= tsubst_stmt (TREE_OPERAND (decl, 1), args, complain, in_decl);
+      tree length = tsubst_stmt (TREE_OPERAND (decl, 2), args, complain,
+				 in_decl);
+      tree base = tsubst_omp_clause_decl (TREE_OPERAND (decl, 0), args,
+					   complain, in_decl, NULL);
+      if (TREE_OPERAND (decl, 0) == base
+	  && TREE_OPERAND (decl, 1) == low_bound
+	  && TREE_OPERAND (decl, 2) == length)
+	return decl;
+      return build3 (OMP_ARRAY_SECTION, TREE_TYPE (base), base, low_bound,
+		     length);
+    }
   tree ret = tsubst_stmt (decl, args, complain, in_decl);
   /* Undo convert_from_reference tsubst_expr could have called.  */
   if (decl
@@ -20230,6 +20246,27 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 				 RECUR (TREE_OPERAND (t, 1)),
 				 complain|decltype_flag));
 
+    case OMP_ARRAY_SECTION:
+      {
+	tree op0 = RECUR (TREE_OPERAND (t, 0));
+	tree op1 = NULL_TREE, op2 = NULL_TREE;
+	if (op0 == error_mark_node)
+	  RETURN (error_mark_node);
+	if (TREE_OPERAND (t, 1))
+	  {
+	    op1 = RECUR (TREE_OPERAND (t, 1));
+	    if (op1 == error_mark_node)
+	      RETURN (error_mark_node);
+	  }
+	if (TREE_OPERAND (t, 2))
+	  {
+	    op2 = RECUR (TREE_OPERAND (t, 2));
+	    if (op2 == error_mark_node)
+	      RETURN (error_mark_node);
+	  }
+	RETURN (build_omp_array_section (EXPR_LOCATION (t), op0, op1, op2));
+      }
+
     case SIZEOF_EXPR:
       if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))
 	  || ARGUMENT_PACK_P (TREE_OPERAND (t, 0)))
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 082fe2d..2162c57 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -5426,7 +5426,7 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
 {
   tree ret, low_bound, length, type;
   bool openacc = (ort & C_ORT_ACC) != 0;
-  if (TREE_CODE (t) != TREE_LIST)
+  if (TREE_CODE (t) != OMP_ARRAY_SECTION)
     {
       if (error_operand_p (t))
 	return error_mark_node;
@@ -5448,7 +5448,9 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
       ret = t_refto;
       if (TREE_CODE (t) == FIELD_DECL)
 	ret = finish_non_static_data_member (t, NULL_TREE, NULL_TREE);
-      else if (!VAR_P (t) && TREE_CODE (t) != PARM_DECL)
+      else if (!VAR_P (t)
+	       && (openacc || !EXPR_P (t))
+	       && TREE_CODE (t) != PARM_DECL)
 	{
 	  if (processing_template_decl && TREE_CODE (t) != OVERLOAD)
 	    return NULL_TREE;
@@ -5481,16 +5483,16 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
       && (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
 	  || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_IN_REDUCTION
 	  || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_TASK_REDUCTION)
-      && TREE_CODE (TREE_CHAIN (t)) == FIELD_DECL)
-    TREE_CHAIN (t) = omp_privatize_field (TREE_CHAIN (t), false);
-  ret = handle_omp_array_sections_1 (c, TREE_CHAIN (t), types,
+      && TREE_CODE (TREE_OPERAND (t, 0)) == FIELD_DECL)
+    TREE_OPERAND (t, 0) = omp_privatize_field (TREE_OPERAND (t, 0), false);
+  ret = handle_omp_array_sections_1 (c, TREE_OPERAND (t, 0), types,
 				     maybe_zero_len, first_non_one, ort);
   if (ret == error_mark_node || ret == NULL_TREE)
     return ret;
 
   type = TREE_TYPE (ret);
-  low_bound = TREE_PURPOSE (t);
-  length = TREE_VALUE (t);
+  low_bound = TREE_OPERAND (t, 1);
+  length = TREE_OPERAND (t, 2);
   if ((low_bound && type_dependent_expression_p (low_bound))
       || (length && type_dependent_expression_p (length)))
     return NULL_TREE;
@@ -5696,7 +5698,7 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
 	  tree lb = cp_save_expr (low_bound);
 	  if (lb != low_bound)
 	    {
-	      TREE_PURPOSE (t) = lb;
+	      TREE_OPERAND (t, 1) = lb;
 	      low_bound = lb;
 	    }
 	}
@@ -5727,14 +5729,14 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
 	 array-section-subscript, the array section could be non-contiguous.  */
       if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_AFFINITY
 	  && OMP_CLAUSE_CODE (c) != OMP_CLAUSE_DEPEND
-	  && TREE_CODE (TREE_CHAIN (t)) == TREE_LIST)
+	  && TREE_CODE (TREE_OPERAND (t, 0)) == OMP_ARRAY_SECTION)
 	{
 	  /* If any prior dimension has a non-one length, then deem this
 	     array section as non-contiguous.  */
-	  for (tree d = TREE_CHAIN (t); TREE_CODE (d) == TREE_LIST;
-	       d = TREE_CHAIN (d))
+	  for (tree d = TREE_OPERAND (t, 0); TREE_CODE (d) == OMP_ARRAY_SECTION;
+	       d = TREE_OPERAND (d, 0))
 	    {
-	      tree d_length = TREE_VALUE (d);
+	      tree d_length = TREE_OPERAND (d, 2);
 	      if (d_length == NULL_TREE || !integer_onep (d_length))
 		{
 		  error_at (OMP_CLAUSE_LOCATION (c),
@@ -5757,7 +5759,7 @@ handle_omp_array_sections_1 (tree c, tree t, vec<tree> &types,
   tree lb = cp_save_expr (low_bound);
   if (lb != low_bound)
     {
-      TREE_PURPOSE (t) = lb;
+      TREE_OPERAND (t, 1) = lb;
       low_bound = lb;
     }
   /* Temporarily disable -fstrong-eval-order for array reductions.
@@ -5835,10 +5837,12 @@ handle_omp_array_sections (tree &c, enum c_omp_region_type ort)
 	return false;
 
       for (i = num, t = OMP_CLAUSE_DECL (c); i > 0;
-	   t = TREE_CHAIN (t))
+	   t = TREE_OPERAND (t, 0))
 	{
-	  tree low_bound = TREE_PURPOSE (t);
-	  tree length = TREE_VALUE (t);
+	  gcc_assert (TREE_CODE (t) == OMP_ARRAY_SECTION);
+
+	  tree low_bound = TREE_OPERAND (t, 1);
+	  tree length = TREE_OPERAND (t, 2);
 
 	  i--;
 	  if (low_bound
@@ -6951,8 +6955,8 @@ cp_oacc_check_attachments (tree c)
       tree t = OMP_CLAUSE_DECL (c);
       tree type;
 
-      while (TREE_CODE (t) == TREE_LIST)
-	t = TREE_CHAIN (t);
+      while (TREE_CODE (t) == OMP_ARRAY_SECTION)
+	t = TREE_OPERAND (t, 0);
 
       type = TREE_TYPE (t);
 
@@ -7059,7 +7063,7 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 	case OMP_CLAUSE_TASK_REDUCTION:
 	  field_ok = ((ort & C_ORT_OMP_DECLARE_SIMD) == C_ORT_OMP);
 	  t = OMP_CLAUSE_DECL (c);
-	  if (TREE_CODE (t) == TREE_LIST)
+	  if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 	    {
 	      if (handle_omp_array_sections (c, ort))
 		{
@@ -7075,10 +7079,10 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 		  remove = true;
 		  break;
 		}
-	      if (TREE_CODE (t) == TREE_LIST)
+	      if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 		{
-		  while (TREE_CODE (t) == TREE_LIST)
-		    t = TREE_CHAIN (t);
+		  while (TREE_CODE (t) == OMP_ARRAY_SECTION)
+		    t = TREE_OPERAND (t, 0);
 		}
 	      else
 		{
@@ -8102,7 +8106,7 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 	  else
 	    last_iterators = NULL_TREE;
 
-	  if (TREE_CODE (t) == TREE_LIST)
+	  if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 	    {
 	      if (handle_omp_array_sections (c, ort))
 		remove = true;
@@ -8262,7 +8266,7 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 	    auto_vec<omp_addr_token *, 10> addr_tokens;
 
 	    t = OMP_CLAUSE_DECL (c);
-	    if (TREE_CODE (t) == TREE_LIST)
+	    if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 	      {
 		grp_start_p = pc;
 		grp_sentinel = OMP_CLAUSE_CHAIN (c);
@@ -8272,7 +8276,7 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 		else
 		  {
 		    t = OMP_CLAUSE_DECL (c);
-		    if (TREE_CODE (t) != TREE_LIST
+		    if (TREE_CODE (t) != OMP_ARRAY_SECTION
 			&& !type_dependent_expression_p (t)
 			&& !omp_mappable_type (TREE_TYPE (t)))
 		      {
@@ -8455,7 +8459,8 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 		if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
 		    && (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER
 			|| OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_ALWAYS_POINTER
-			|| OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_ATTACH_DETACH))
+			|| OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_ATTACH_DETACH
+			|| (!openacc && EXPR_P (t))))
 		  break;
 		if (DECL_P (t))
 		  error_at (OMP_CLAUSE_LOCATION (c),
@@ -8854,15 +8859,15 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 
 	case OMP_CLAUSE_HAS_DEVICE_ADDR:
 	  t = OMP_CLAUSE_DECL (c);
-	  if (TREE_CODE (t) == TREE_LIST)
+	  if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 	    {
 	      if (handle_omp_array_sections (c, ort))
 		remove = true;
 	      else
 		{
 		  t = OMP_CLAUSE_DECL (c);
-		  while (TREE_CODE (t) == TREE_LIST)
-		    t = TREE_CHAIN (t);
+		  while (TREE_CODE (t) == OMP_ARRAY_SECTION)
+		    t = TREE_OPERAND (t, 0);
 		  while (INDIRECT_REF_P (t)
 			 || TREE_CODE (t) == ARRAY_REF)
 		    t = TREE_OPERAND (t, 0);
@@ -9234,10 +9239,10 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
 		  if (DECL_P (t))
 		    bitmap_clear_bit (&aligned_head, DECL_UID (t));
 		}
-	      else if (TREE_CODE (t) == TREE_LIST)
+	      else if (TREE_CODE (t) == OMP_ARRAY_SECTION)
 		{
-		  while (TREE_CODE (t) == TREE_LIST)
-		    t = TREE_CHAIN (t);
+		  while (TREE_CODE (t) == OMP_ARRAY_SECTION)
+		    t = TREE_OPERAND (t, 0);
 		  if (DECL_P (t))
 		    bitmap_clear_bit (&aligned_head, DECL_UID (t));
 		  t = OMP_CLAUSE_DECL (c);
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 49e9674..cfcaf12 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -4796,6 +4796,56 @@ build_x_array_ref (location_t loc, tree arg1, tree arg2,
   return expr;
 }
 
+/* Build an OpenMP array section reference, creating an exact type for the
+   resulting expression based on the element type and bounds if possible.  If
+   we have variable bounds, create an incomplete array type for the result
+   instead.  */
+
+tree
+build_omp_array_section (location_t loc, tree array_expr, tree index,
+			 tree length)
+{
+  tree type = TREE_TYPE (array_expr);
+  gcc_assert (type);
+  type = non_reference (type);
+
+  tree sectype, eltype = TREE_TYPE (type);
+
+  /* It's not an array or pointer type.  Just reuse the type of the
+     original expression as the type of the array section (an error will be
+     raised anyway, later).  */
+  if (eltype == NULL_TREE)
+    sectype = TREE_TYPE (array_expr);
+  else
+    {
+      tree idxtype = NULL_TREE;
+
+      /* If we know the integer bounds, create an index type with exact
+	 low/high (or zero/length) bounds.  Otherwise, create an incomplete
+	 array type.  (This mostly only affects diagnostics.)  */
+      if (index != NULL_TREE
+	  && length != NULL_TREE
+	  && TREE_CODE (index) == INTEGER_CST
+	  && TREE_CODE (length) == INTEGER_CST)
+	{
+	  tree low = fold_convert (sizetype, index);
+	  tree high = fold_convert (sizetype, length);
+	  high = size_binop (PLUS_EXPR, low, high);
+	  high = size_binop (MINUS_EXPR, high, size_one_node);
+	  idxtype = build_range_type (sizetype, low, high);
+	}
+      else if ((index == NULL_TREE || integer_zerop (index))
+	       && length != NULL_TREE
+	       && TREE_CODE (length) == INTEGER_CST)
+	idxtype = build_index_type (length);
+
+      sectype = build_array_type (eltype, idxtype);
+    }
+
+  return build3_loc (loc, OMP_ARRAY_SECTION, sectype, array_expr, index,
+		     length);
+}
+
 /* Return whether OP is an expression of enum type cast to integer
    type.  In C++ even unsigned enum types are cast to signed integer
    types.  We do not want to issue warnings about comparisons between
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 4ed7a07..7f79b3c 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -13502,7 +13502,11 @@ gimplify_adjust_omp_clauses_1 (splay_tree_node n, void *data)
       if (TREE_CODE (dtype) == REFERENCE_TYPE)
 	dtype = TREE_TYPE (dtype);
       /* FIRSTPRIVATE_POINTER doesn't work well if we have a
-	 multiply-indirected pointer.  */
+	 multiply-indirected pointer.  If we have a reference to a pointer to
+	 a pointer, it's possible that this should really be
+	 GOMP_MAP_FIRSTPRIVATE_REFERENCE -- but that also doesn't work at the
+	 moment, so stick with this.  (See PR113279 and testcases
+	 baseptrs-{4,6}.C:ref2ptrptr_offset_decl_member_slice).  */
       if (TREE_CODE (dtype) == POINTER_TYPE
 	  && TREE_CODE (TREE_TYPE (dtype)) == POINTER_TYPE)
 	OMP_CLAUSE_SET_MAP_KIND (nc, GOMP_MAP_POINTER);
@@ -17759,6 +17763,9 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 	case TREE_LIST:
 	  gcc_unreachable ();
 
+	case OMP_ARRAY_SECTION:
+	  gcc_unreachable ();
+
 	case COMPOUND_EXPR:
 	  ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
 	  break;
diff --git a/gcc/testsuite/c-c++-common/gomp/map-6.c b/gcc/testsuite/c-c++-common/gomp/map-6.c
index 5152d9d..014ed35 100644
--- a/gcc/testsuite/c-c++-common/gomp/map-6.c
+++ b/gcc/testsuite/c-c++-common/gomp/map-6.c
@@ -30,12 +30,12 @@ foo (void)
 
 
   #pragma omp target map (close a) /* { dg-error "'close' undeclared" "" { target c } } */ 
-  /* { dg-error "'close' has not been declared" "" { target c++ } .-1 } */ 
+  /* { dg-error "'close' was not declared in this scope" "" { target c++ } .-1 } */ 
   /* { dg-error "expected '\\)' before 'a'" "" { target *-*-* } .-2 } */
   ;
 
   #pragma omp target map (always a) /* { dg-error "'always' undeclared" "" { target c } } */
-  /* { dg-error "'always' has not been declared" "" { target c++ } .-1 } */ 
+  /* { dg-error "'always' was not declared in this scope" "" { target c++ } .-1 } */ 
   /* { dg-error "expected '\\)' before 'a'" "" { target *-*-* } .-2 } */
   ;
 
diff --git a/gcc/testsuite/c-c++-common/gomp/target-enter-data-1.c b/gcc/testsuite/c-c++-common/gomp/target-enter-data-1.c
index 3e5d5c7..4dc5188 100644
--- a/gcc/testsuite/c-c++-common/gomp/target-enter-data-1.c
+++ b/gcc/testsuite/c-c++-common/gomp/target-enter-data-1.c
@@ -21,5 +21,5 @@ void func (struct foo *f, int n, int m)
   #pragma omp target enter data map (to: f->bars[n].vectors[:f->bars[n].num_vectors])
 }
 
-/* { dg-final { scan-tree-dump-times {map\(struct:\*f \[len: 1\]\) map\(alloc:[a-z0-9\._]+->vectors \[len: 0\]\) map\(to:\*_[0-9]+ \[len: _[0-9]+\]\) map\(attach:[a-z0-9\._]+->vectors \[bias: [^\]]+\]\) map\(attach:\*_[0-9]+ \[bias: _[0-9]+\]\)} 1 "gimple" } } */
+/* { dg-final { scan-tree-dump-times {map\(struct:\*f \[len: 1\]\) map\(alloc:[a-z0-9\._]+->vectors \[len: 0\]\) map\(to:\*_[0-9]+ \[len: _[0-9]+\]\) map\(attach:[a-z0-9\._]+->vectors \[bias: [^\]]+\]\) map\(attach:\*_[0-9]+ \[bias: [^\]]+\]\)} 1 "gimple" } } */
 /* { dg-final { scan-tree-dump-times {map\(struct:\*\(f->bars \+ \(sizetype\) \(\([^\)]+\) n \* (?:16|8)\)\) \[len: 1\]\) map\(alloc:[a-z0-9\._]+->vectors \[len: 0\]\) map\(to:\*_[0-9]+ \[len: _[0-9]+\]\) map\(attach:[a-z0-9\._]+->vectors \[bias: [^\]]+\]\)} 2 "gimple" } } */
diff --git a/gcc/testsuite/g++.dg/gomp/array-section-1.C b/gcc/testsuite/g++.dg/gomp/array-section-1.C
new file mode 100644
index 0000000..023706b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/array-section-1.C
@@ -0,0 +1,38 @@
+// { dg-do compile }
+// { dg-additional-options "-fdump-tree-original" }
+
+int x;
+
+template<int C, int D>
+void foo()
+{
+  int arr1[40];
+#pragma omp target map(arr1[x ? C : D])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] \[len: [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[x ? C : D : D])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] \[len: [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[1 : x ? C : D])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[1\] \[len: x != 0 \? [0-9]+ : [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: [0-9]+\]\)} "original" } }
+  { }
+}
+
+int main()
+{
+  int arr1[40];
+#pragma omp target map(arr1[x ? 3 : 5])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] \[len: [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[x ? 3 : 5 : 5])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] \[len: [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x != 0 \? 3 : 5>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[1 : x ? 3 : 5])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[1\] [len: x != 0 ? [0-9]+ : [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: [0-9]+\]\)} "original" } }
+  { }
+
+  foo<3, 5> ();
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/array-section-2.C b/gcc/testsuite/g++.dg/gomp/array-section-2.C
new file mode 100644
index 0000000..072108d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/array-section-2.C
@@ -0,0 +1,63 @@
+// { dg-do compile }
+// { dg-additional-options "-fdump-tree-original" }
+
+int x, y;
+
+class C {
+  int x, y;
+
+public:
+  int foo();
+};
+
+int C::foo()
+{
+  int arr1[40];
+  /* There is a parsing ambiguity here without the space.  We don't try to
+     resolve that automatically (though maybe we could, in theory).  */
+#pragma omp target map(arr1[::x: ::y])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x>\] \[len: \(sizetype\) y \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[::x:])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x>\] \[len: \(40 - \(sizetype\) SAVE_EXPR <x>\) \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[: ::y])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[0\] \[len: \(sizetype\) y \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: 0\]\)} "original" } }
+  { }
+  return ::x + ::y;
+}
+
+template<typename T>
+class Ct {
+  T x, y;
+
+public:
+  void foo();
+};
+
+template<typename T>
+void Ct<T>::foo()
+{
+  int arr1[40];
+#pragma omp target map(arr1[::x: ::y])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x>\] \[len: \(sizetype\) y \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[::x:])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[SAVE_EXPR <x>\] \[len: \(40 - \(sizetype\) SAVE_EXPR <x>\) \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: \(long int\) &arr1\[SAVE_EXPR <x>\] - \(long int\) &arr1\]\)} "original" } }
+  { }
+#pragma omp target map(arr1[: ::y])
+// { dg-final { scan-tree-dump {map\(tofrom:arr1\[0\] \[len: \(sizetype\) y \* [0-9]+\]\) map\(firstprivate:arr1 \[pointer assign, bias: 0\]\)} "original" } }
+  { }
+}
+
+int main()
+{
+  C c;
+  Ct<int> ct;
+
+  c.foo ();
+  ct.foo ();
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-1.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-1.C
new file mode 100644
index 0000000..7e7e958
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-1.C
@@ -0,0 +1,35 @@
+// { dg-do compile }
+
+int foo (int *ptr);
+
+template<typename T>
+T baz (T *ptr);
+
+template<typename T>
+void bar()
+{
+  T arr[20];
+
+#pragma omp target map(baz(arr[3:5]))
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {expected '\)' before ':' token} "" { target *-*-* } .-2 }
+// { dg-error {expected '\)' before '\]' token} "" { target *-*-* } .-3 }
+// { dg-error {expected an OpenMP clause before '\]' token} "" { target *-*-* } .-4 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+  // Reject array section as function argument.
+#pragma omp target map(foo(arr[3:5]))
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {expected '\)' before ':' token} "" { target *-*-* } .-2 }
+// { dg-error {expected '\)' before '\]' token} "" { target *-*-* } .-3 }
+// { dg-error {expected an OpenMP clause before '\]' token} "" { target *-*-* } .-4 }
+  { }
+
+  bar<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-10.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-10.C
new file mode 100644
index 0000000..393b0fe
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-10.C
@@ -0,0 +1,35 @@
+// { dg-do compile }
+
+template<int C, int D>
+void foo()
+{
+  int arr1[40];
+#pragma omp target map(arr1[4,C:])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+#pragma omp target map(arr1[4,5:C,7])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+#pragma omp target map(arr1[:8,C,10])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr1[40];
+#pragma omp target map(arr1[4,5:])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+#pragma omp target map(arr1[4,5:6,7])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+#pragma omp target map(arr1[:8,9,10])
+// { dg-warning "top-level comma expression in array subscript is deprecated" "" { target c++20_only } .-1 }
+  { }
+
+  foo<6, 9> ();
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-11.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-11.C
new file mode 100644
index 0000000..dea3b44
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-11.C
@@ -0,0 +1,36 @@
+// { dg-do compile }
+// { dg-additional-options "-std=c++23" }
+
+template<int C, int D>
+void foo()
+{
+  int arr1[40];
+#pragma omp target map(arr1[4,C:])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[4,5:C,7])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[:8,C,10])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr1[40];
+#pragma omp target map(arr1[4,5:])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[4,5:6,7])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[:8,9,10])
+// { dg-error "cannot use multidimensional subscript in OpenMP array section" "" { target *-*-* } .-1 }
+  { }
+
+  foo<6, 9> ();
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-2.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-2.C
new file mode 100644
index 0000000..811d1fe
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-2.C
@@ -0,0 +1,33 @@
+// { dg-do compile }
+// { dg-additional-options "-std=c++11" }
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+  // Reject array section in lambda function.
+#pragma omp target map([&](const int x) -> T* { return arr[0:x]; } (5))
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {invalid conversion from 'int' to 'int\*'} "" { target *-*-* } .-2 }
+// { dg-error {expected ';' before ':' token} "" { target *-*-* } .-3 }
+// { dg-error {expected primary-expression before ':' token} "" { target *-*-* } .-4 }
+// { dg-message {sorry, unimplemented: unsupported map expression '<lambda closure object>foo<int>\(\)::<lambda\(int\)>\{arr\}.foo<int>\(\)::<lambda\(int\)>\(5\)'} "" { target *-*-* } .-5 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+  // Reject array section in lambda function.
+#pragma omp target map([&](const int x) -> int* { return arr[0:x]; } (5))
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {invalid conversion from 'int' to 'int\*'} "" { target *-*-* } .-2 }
+// { dg-error {expected ';' before ':' token} "" { target *-*-* } .-3 }
+// { dg-error {expected primary-expression before ':' token} "" { target *-*-* } .-4 }
+// { dg-message {sorry, unimplemented: unsupported map expression '<lambda closure object>main\(\)::<lambda\(int\)>\{arr\}.main\(\)::<lambda\(int\)>\(5\)'} "" { target *-*-* } .-5 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-3.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-3.C
new file mode 100644
index 0000000..d1f067a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-3.C
@@ -0,0 +1,28 @@
+// { dg-do compile }
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+  // Reject array section in statement expression.
+#pragma omp target map( ({ int x = 5; arr[0:x]; }) )
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {expected ';' before ':' token} "" { target *-*-* } .-2 }
+// { dg-message {sorry, unimplemented: unsupported map expression '\(\{\.\.\.\}\)'} "" { target *-*-* } .-3 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+  // Reject array section in statement expression.
+#pragma omp target map( ({ int x = 5; arr[0:x]; }) )
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {expected ';' before ':' token} "" { target *-*-* } .-2 }
+// { dg-message {sorry, unimplemented: unsupported map expression '\(\{\.\.\.\}\)'} "" { target *-*-* } .-3 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-4.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-4.C
new file mode 100644
index 0000000..707c2c3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-4.C
@@ -0,0 +1,50 @@
+// { dg-do compile }
+
+template<typename T>
+struct St {
+  T *ptr;
+};
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+
+  // Reject array section in compound initialiser.
+#pragma omp target map( (struct St<T>) { .ptr = (T *) arr[5:5] } )
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-error {expected primary-expression before 'struct'} "" { target *-*-* } .-2 }
+// { dg-error {expected '\)' before 'struct'} "" { target *-*-* } .-3 }
+  { }
+
+  // ...and this is unsupported too (probably not useful anyway).
+#pragma omp target map( (struct St<T>) { .ptr = &arr[5] } )
+// { dg-message {sorry, unimplemented: unsupported map expression 'St<int>\{\(\& arr\[5\]\)\}'} "" { target *-*-* } .-1 }
+  { }
+}
+
+struct S {
+  int *ptr;
+};
+
+int main()
+{
+  int arr[20];
+
+  // Reject array section in compound initialiser.
+#pragma omp target map( (struct S) { .ptr = (int *) arr[5:5] } )
+// { dg-error {expected '\]' before ':' token} "" { target *-*-* } .-1 }
+// { dg-warning {cast to pointer from integer of different size} "" { target *-*-* } .-2 }
+// { dg-error {expected primary-expression before 'struct'} "" { target *-*-* } .-3 }
+// { dg-error {expected '\)' before 'struct'} "" { target *-*-* } .-4 }
+  { }
+
+  // ...and this is unsupported too (probably not useful anyway).
+#pragma omp target map( (struct S) { .ptr = &arr[5] } )
+// { dg-message {sorry, unimplemented: unsupported map expression 'S\{\(\& arr\[5\]\)\}'} "" { target *-*-* } .-1 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-5.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-5.C
new file mode 100644
index 0000000..f9c27d4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-5.C
@@ -0,0 +1,50 @@
+// { dg-do compile }
+
+int x;
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+  T *ptr;
+  /* "arr[1:10]" looks like it might be an expression of array type, hence
+     able to be indexed (again).  This isn't allowed, though.  */
+#pragma omp target map(arr[1:10][2])
+// { dg-error {'arr\[1\]' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr[1:x][2])
+// { dg-error {'arr\[1\]' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+  // ...and nor is this.
+#pragma omp target map(ptr[1:10][2])
+// { dg-error {'\*\(ptr \+ [0-9]+\)' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(ptr[1:x][2])
+// { dg-error {'\*\(ptr \+ [0-9]+\)' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+  int *ptr;
+  /* "arr[1:10]" looks like it might be an expression of array type, hence
+     able to be indexed (again).  This isn't allowed, though.  */
+#pragma omp target map(arr[1:10][2])
+// { dg-error {'arr\[1\]' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr[1:x][2])
+// { dg-error {'arr\[1\]' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+  // ...and nor is this.
+#pragma omp target map(ptr[1:10][2])
+// { dg-error {'\*\(ptr \+ [0-9]+\)' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(ptr[1:x][2])
+// { dg-error {'\*\(ptr \+ [0-9]+\)' does not have pointer or array type} "" { target *-*-* } .-1 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-6.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-6.C
new file mode 100644
index 0000000..418ee80
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-6.C
@@ -0,0 +1,24 @@
+// { dg-do compile }
+
+bool partly = false;
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+#pragma omp target map(partly ? arr[5:5] : arr)
+// { dg-message {sorry, unimplemented: unsupported map expression '\(partly \? \(\(int\*\)\(\& arr\[5:5\]\)\) : \(\(int\*\)\(\& arr\)\)\)'} "" { target *-*-* } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+#pragma omp target map(partly ? arr[5:5] : arr)
+// { dg-message {sorry, unimplemented: unsupported map expression '\(partly \? \(\(int\*\)\(\& arr\[5:5\]\)\) : \(\(int\*\)\(\& arr\)\)\)'} "" { target *-*-* } .-1 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-7.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-7.C
new file mode 100644
index 0000000..24ac165
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-7.C
@@ -0,0 +1,36 @@
+// { dg-do compile }
+
+int x;
+
+template<typename T>
+void foo()
+{
+  T arr[20];
+  // Here we know the type of the array section (the upper bound is reported)...
+#pragma omp target map(arr[5:5] * 2)
+// { dg-error {invalid operands of types 'int \[10\]' and 'int'} "" { target *-*-* } .-1 }
+  { }
+  /* ...but here, we have an incomplete array type because of the variable
+     low bound 'x'.  */
+#pragma omp target map(arr[x:5] * 2)
+// { dg-error {invalid operands of types 'int \[\]' and 'int'} "" { target *-*-* } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr[20];
+  // Here we know the type of the array section (the upper bound is reported)...
+#pragma omp target map(arr[5:5] * 2)
+// { dg-error {invalid operands of types 'int \[10\]' and 'int'} "" { target *-*-* } .-1 }
+  { }
+  /* ...but here, we have an incomplete array type because of the variable
+     low bound 'x'.  */
+#pragma omp target map(arr[x:5] * 2)
+// { dg-error {invalid operands of types 'int \[\]' and 'int'} "" { target *-*-* } .-1 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-8.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-8.C
new file mode 100644
index 0000000..2353722
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-8.C
@@ -0,0 +1,53 @@
+// { dg-do compile }
+
+int x;
+
+template<typename X>
+struct Tt {
+  X arr[20];
+};
+
+template<typename X>
+struct St {
+  X *tvec;
+};
+
+template<typename T>
+void foo()
+{
+  struct St<Tt<T> > *s;
+  // You can't use an array section like this.  Make sure sensible errors are
+  // reported.
+#pragma omp target map(s->tvec[3:5].arr[0:20])
+// { dg-error {request for member 'arr' in 's->St<Tt<int> >::tvec\[3:5\]', which is of non-class type 'Tt<int> \[8\]'} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(s->tvec[5:x].arr[0:20])
+// { dg-error {invalid use of array with unspecified bounds} "" { target *-*-* } .-1 }
+  { }
+}
+
+struct T {
+  int arr[20];
+};
+
+struct S {
+  struct T *tvec;
+};
+
+int main()
+{
+  struct S *s;
+  // You can't use an array section like this.  Make sure sensible errors are
+  // reported.
+#pragma omp target map(s->tvec[3:5].arr[0:20])
+// { dg-error {request for member 'arr' in 's->S::tvec\[3:5\]', which is of non-class type 'T \[8\]'} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(s->tvec[5:x].arr[0:20])
+// { dg-error {invalid use of array with unspecified bounds} "" { target *-*-* } .-1 }
+// { dg-error {expected '\)' before 'arr'} "" { target *-*-* } .-2 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/bad-array-section-9.C b/gcc/testsuite/g++.dg/gomp/bad-array-section-9.C
new file mode 100644
index 0000000..bba7772
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/bad-array-section-9.C
@@ -0,0 +1,39 @@
+// { dg-do compile }
+
+int x;
+
+template<typename T>
+void foo()
+{
+  T arr1[40];
+  T arr2[40];
+#pragma omp target map(arr1[arr2[4:5]:arr2[6:7]])
+// { dg-error {low bound 'arr2\[4:5\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[arr2[:1]:arr2[6:1]])
+// { dg-error {low bound 'arr2\[:1\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[x:arr2[6:1]])
+// { dg-error {length 'arr2\[6:1\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+}
+
+int main()
+{
+  int arr1[40];
+  int arr2[40];
+#pragma omp target map(arr1[arr2[4:5]:arr2[6:7]])
+// { dg-error {low bound 'arr2\[4:5\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[arr2[:1]:arr2[6:1]])
+// { dg-error {low bound 'arr2\[:1\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+#pragma omp target map(arr1[x:arr2[6:1]])
+// { dg-error {length 'arr2\[6:1\]' of array section does not have integral type} "" { target *-*-* } .-1 }
+  { }
+
+  foo<int> ();
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/has_device_addr-non-lvalue-1.C b/gcc/testsuite/g++.dg/gomp/has_device_addr-non-lvalue-1.C
new file mode 100644
index 0000000..3d77853
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/has_device_addr-non-lvalue-1.C
@@ -0,0 +1,36 @@
+// { dg-do compile }
+
+#include <cstdio>
+#include <cstring>
+#include <cassert>
+
+typedef struct {
+  int arr[100];
+} S;
+
+int main()
+{
+  S *s = new S;
+
+  memset (s->arr, '\0', sizeof s->arr); 
+
+#pragma omp target enter data map(to: (*s).arr)
+  /* You can't do this, at least as of OpenMP 5.2.  "has_device_addr" takes
+     a "variable list" item type
+     (OpenMP 5.2, "5.4.9 has_device_addr Clause").  */
+#pragma omp target has_device_addr((*s).arr[5:20])
+// { dg-error {expected unqualified-id before '\(' token} "" { target *-*-* } .-1 }
+  {
+    for (int i = 5; i < 25; i++)
+      s->arr[i] = i; 
+  }
+
+#pragma omp target exit data map(from: (*s).arr)
+
+  for (int i = 0; i < 100; i++)
+    assert (i >= 5 && i < 25 ? s->arr[i] == i : s->arr[i] == 0);
+
+  delete s;
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/ind-base-3.C b/gcc/testsuite/g++.dg/gomp/ind-base-3.C
new file mode 100644
index 0000000..7695b1f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/ind-base-3.C
@@ -0,0 +1,37 @@
+#include <cassert>
+
+struct S {
+  int x[10];
+};
+
+S *
+choose (S *a, S *b, int c)
+{
+  if (c < 5)
+    return a;
+  else
+    return b; 
+}
+
+int main (int argc, char *argv[])
+{
+  S a, b;
+
+  for (int i = 0; i < 10; i++)
+    a.x[i] = b.x[i] = 0;
+
+  for (int i = 0; i < 10; i++)
+    {
+#pragma omp target map(choose(&a, &b, i)->x[:10])
+/* { dg-message {sorry, unimplemented: unsupported map expression 'choose\(\(& a\), \(& b\), i\)->S::x\[0\]'} "" { target *-*-* } .-1 } */
+      for (int j = 0; j < 10; j++)
+        choose (&a, &b, i)->x[j]++;
+    }
+
+  for (int i = 0; i < 10; i++)
+    assert (a.x[i] == 5 && b.x[i] == 5);
+
+  return 0;
+}
+
+
diff --git a/gcc/testsuite/g++.dg/gomp/map-assignment-1.C b/gcc/testsuite/g++.dg/gomp/map-assignment-1.C
new file mode 100644
index 0000000..5979ec3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-assignment-1.C
@@ -0,0 +1,12 @@
+#include <cassert>
+
+int main (int argc, char *argv[])
+{
+  int a = 5, b = 2;
+#pragma omp target map(a += b)
+  /* { dg-message {sorry, unimplemented: unsupported map expression '\(a = \(a \+ b\)\)'} "" { target *-*-* } .-1 } */
+  {
+    a++;
+  }
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-inc-1.C b/gcc/testsuite/g++.dg/gomp/map-inc-1.C
new file mode 100644
index 0000000..b469a4b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-inc-1.C
@@ -0,0 +1,10 @@
+int main (int argc, char *argv[])
+{
+  int a = 5;
+#pragma omp target map(++a)
+  /* { dg-message {sorry, unimplemented: unsupported map expression '\+\+ a'} "" { target *-*-* } .-1 } */
+  {
+    a++;
+  }
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-lvalue-ref-1.C b/gcc/testsuite/g++.dg/gomp/map-lvalue-ref-1.C
new file mode 100644
index 0000000..d720d43
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-lvalue-ref-1.C
@@ -0,0 +1,19 @@
+#include <cassert>
+
+int glob = 10;
+
+int& foo ()
+{
+  return glob;
+}
+
+int main (int argc, char *argv[])
+{
+#pragma omp target map(foo())
+  /* { dg-message {sorry, unimplemented: unsupported map expression 'foo\(\)'} "" { target *-*-* } .-1 } */
+  {
+    foo()++;
+  }
+  assert (glob == 11);
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-ptrmem-1.C b/gcc/testsuite/g++.dg/gomp/map-ptrmem-1.C
new file mode 100644
index 0000000..c4023f5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-ptrmem-1.C
@@ -0,0 +1,37 @@
+#include <cassert>
+
+struct S {
+  int x;
+  int *ptr;
+};
+
+int
+main (int argc, char *argv[])
+{
+  S s;
+  int S::* xp = &S::x;
+  int* S::* ptrp = &S::ptr;
+
+  s.ptr = new int[64];
+
+  s.*xp = 6;
+  for (int i = 0; i < 64; i++)
+    (s.*ptrp)[i] = i;
+
+#pragma omp target map(s.*xp, s.*ptrp, (s.*ptrp)[:64])
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\*\(\(\(int\*\*\)\(& s\)\) \+ \(\(sizetype\)ptrp\)\)\)' not supported} "" { target *-*-* } .-1 } */
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\(\(int\*\*\)\(& s\)\) \+ \(\(sizetype\)ptrp\)\)' not supported} "" { target *-*-* } .-2 } */
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\(\(int\*\)\(& s\)\) \+ \(\(sizetype\)xp\)\)' not supported} "" { target *-*-* } .-3 } */
+#pragma omp teams distribute parallel for
+  for (int i = 0; i < 64; i++)
+    {
+      (s.*xp)++;
+      (s.*ptrp)[i]++;
+    }
+
+  assert (s.*xp == 70);
+  for (int i = 0; i < 64; i++)
+    assert ((s.*ptrp)[i] == i + 1);
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-ptrmem-2.C b/gcc/testsuite/g++.dg/gomp/map-ptrmem-2.C
new file mode 100644
index 0000000..fbf379d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-ptrmem-2.C
@@ -0,0 +1,40 @@
+#include <cassert>
+
+struct S {
+  int x;
+  int *ptr;
+};
+
+int
+main (int argc, char *argv[])
+{
+  S *s = new S;
+  int S::* xp = &S::x;
+  int* S::* ptrp = &S::ptr;
+
+  s->ptr = new int[64];
+
+  s->*xp = 4;
+  for (int i = 0; i < 64; i++)
+    (s->*ptrp)[i] = i;
+
+#pragma omp target map(s->*xp, s->*ptrp, (s->*ptrp)[:64])
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\(\(int\*\*\)s\) \+ \(\(sizetype\)ptrp\)\)' not supported} "" { target *-*-* } .-1 } */
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\(\(int\*\)s\) \+ \(\(sizetype\)xp\)\)' not supported} "" { target *-*-* } .-2 } */
+  /* { dg-message {sorry, unimplemented: pointer-to-member mapping '\*\(\*\(\(\(int\*\*\)s\) \+ \(\(sizetype\)ptrp\)\)\)' not supported} "" { target *-*-* } .-3 } */
+#pragma omp teams distribute parallel for
+  for (int i = 0; i < 64; i++)
+    {
+      (s->*xp)++;
+      (s->*ptrp)[i]++;
+    }
+
+  assert (s->*xp == 68);
+  for (int i = 0; i < 64; i++)
+    assert ((s->*ptrp)[i] == i + 1);
+
+  delete s->ptr;
+  delete s;
+
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-static-cast-lvalue-1.C b/gcc/testsuite/g++.dg/gomp/map-static-cast-lvalue-1.C
new file mode 100644
index 0000000..3af9668
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-static-cast-lvalue-1.C
@@ -0,0 +1,17 @@
+#include <cassert>
+
+int foo (int x)
+{
+#pragma omp target map(static_cast<int&>(x))
+  /* { dg-message {sorry, unimplemented: unsupported map expression '& x'} "" { target *-*-* } .-1 } */
+  {
+    x += 3;
+  }
+  return x;
+}
+
+int main (int argc, char *argv[])
+{
+  assert (foo (5) == 8);
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/map-ternary-1.C b/gcc/testsuite/g++.dg/gomp/map-ternary-1.C
new file mode 100644
index 0000000..7b365a9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/map-ternary-1.C
@@ -0,0 +1,20 @@
+#include <cassert>
+
+int foo (bool yesno)
+{
+  int x = 5, y = 7;
+#pragma omp target map(yesno ? x : y)
+  /* { dg-message {sorry, unimplemented: unsupported map expression '\(yesno \?  x :  y\)'} "" { target *-*-* } .-1 } */
+  {
+    x += 3;
+    y += 5;
+  }
+  return yesno ? x : y;
+}
+
+int main (int argc, char *argv[])
+{
+  assert (foo (true) == 8);
+  assert (foo (false) == 12);
+  return 0;
+}
diff --git a/gcc/testsuite/g++.dg/gomp/member-array-2.C b/gcc/testsuite/g++.dg/gomp/member-array-2.C
new file mode 100644
index 0000000..caf8ece
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/member-array-2.C
@@ -0,0 +1,91 @@
+#include <cassert>
+
+typedef int intarr100[100];
+
+class C {
+  int arr[100];
+  int *ptr;
+
+public:
+  C();
+  ~C();
+  void zero ();
+  void do_operation ();
+  void check (int, int);
+  intarr100 &get_arr () { return arr; }
+  int *get_ptr() { return ptr; }
+};
+
+C::C()
+{
+  ptr = new int[100];
+  for (int i = 0; i < 100; i++)
+    arr[i] = 0;
+}
+
+C::~C()
+{
+  delete ptr;
+}
+
+void
+C::zero ()
+{
+  for (int i = 0; i < 100; i++)
+    arr[i] = ptr[i] = 0;
+}
+
+void
+C::do_operation ()
+{
+#pragma omp target map(arr, ptr, ptr[:100])
+#pragma omp teams distribute parallel for
+  for (int i = 0; i < 100; i++)
+    {
+      arr[i] = arr[i] + 3;
+      ptr[i] = ptr[i] + 5;
+    }
+}
+
+void
+C::check (int arrval, int ptrval)
+{
+  for (int i = 0; i < 100; i++)
+    {
+      assert (arr[i] == arrval);
+      assert (ptr[i] == ptrval);
+    }
+}
+
+int
+main (int argc, char *argv[])
+{
+  C c;
+
+  c.zero ();
+  c.do_operation ();
+  c.check (3, 5);
+
+  /* It might sort of make sense to be able to do this, but we don't support
+     it for now.  */
+  #pragma omp target map(c.get_arr()[:100])
+  /* { dg-message {sorry, unimplemented: unsupported map expression 'c\.C::get_arr\(\)\[0\]'} "" { target *-*-* } .-1 } */
+  #pragma omp teams distribute parallel for
+    for (int i = 0; i < 100; i++)
+      c.get_arr()[i] += 2;
+
+  c.check (5, 5);
+
+  /* Same for this.  */
+  #pragma omp target map(c.get_ptr(), c.get_ptr()[:100])
+  /* { dg-message {sorry, unimplemented: unsupported map expression 'c\.C::get_ptr\(\)'} "" { target *-*-* } .-1 } */
+  /* { dg-message {sorry, unimplemented: unsupported map expression '\* c\.C::get_ptr\(\)'} "" { target *-*-* } .-2 } */
+  #pragma omp teams distribute parallel for
+    for (int i = 0; i < 100; i++)
+      c.get_ptr()[i] += 3;
+
+  c.check (5, 8);
+
+  return 0;
+}
+
diff --git a/gcc/testsuite/g++.dg/gomp/pr67522.C b/gcc/testsuite/g++.dg/gomp/pr67522.C
index da8cb74..4a901ba 100644
--- a/gcc/testsuite/g++.dg/gomp/pr67522.C
+++ b/gcc/testsuite/g++.dg/gomp/pr67522.C
@@ -12,7 +12,7 @@ foo (void)
   for (int i = 0; i < 16; i++)
     ;
 
-  #pragma omp target map (S[0:10])		// { dg-error "is not a variable in" }
+  #pragma omp target map (S[0:10])		// { dg-error "expected primary-expression before '\\\[' token" }
   ;
 
   #pragma omp task depend (inout: S[0:10])	// { dg-error "is not a variable in" }
diff --git a/gcc/tree-pretty-print.cc b/gcc/tree-pretty-print.cc
index 04ac85f..654f524 100644
--- a/gcc/tree-pretty-print.cc
+++ b/gcc/tree-pretty-print.cc
@@ -2729,6 +2729,20 @@ dump_generic_node (pretty_printer *pp, tree node, int spc, dump_flags_t flags,
 	}
       break;
 
+    case OMP_ARRAY_SECTION:
+      op0 = TREE_OPERAND (node, 0);
+      if (op_prio (op0) < op_prio (node))
+	pp_left_paren (pp);
+      dump_generic_node (pp, op0, spc, flags, false);
+      if (op_prio (op0) < op_prio (node))
+	pp_right_paren (pp);
+      pp_left_bracket (pp);
+      dump_generic_node (pp, TREE_OPERAND (node, 1), spc, flags, false);
+      pp_colon (pp);
+      dump_generic_node (pp, TREE_OPERAND (node, 2), spc, flags, false);
+      pp_right_bracket (pp);
+      break;
+
     case CONSTRUCTOR:
       {
 	unsigned HOST_WIDE_INT ix;
diff --git a/gcc/tree.def b/gcc/tree.def
index d07cea5..24128e1 100644
--- a/gcc/tree.def
+++ b/gcc/tree.def
@@ -1370,6 +1370,9 @@ DEFTREECODE (OMP_ATOMIC_CAPTURE_NEW, "omp_atomic_capture_new", tcc_statement, 2)
 /* OpenMP clauses.  */
 DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0)
 
+/* An OpenMP array section.  */
+DEFTREECODE (OMP_ARRAY_SECTION, "omp_array_section", tcc_expression, 3)
+
 /* TRANSACTION_EXPR tree code.
    Operand 0: BODY: contains body of the transaction.  */
 DEFTREECODE (TRANSACTION_EXPR, "transaction_expr", tcc_expression, 1)