[C++ PATCH] Reserve a decl_lang bit

https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00365.html
	Reserve TREE_LANG_FLAG_3 for modules.
	gcc/cp/
	* cp-tree.h (DECL_CONSTRUCTION_VTABLE_P): Delete.
	(DECL_NON_TRIVIALLY_INITIALIZED_P): Move to TREE_LANG_FLAG_6.
	* class.c (build_ctor_vtbl_group): Don't set
	DECL_CONSTRUCTION_VTABLE_P.
	* decl2.c (determine_visibility_from_class): Don't check
	DECL_CONSTRUCTION_VTABLE_P anymore.

From-SVN: r275455

gcc/cp/ChangeLog

+2019-09-06  Nathan Sidwell  <nathan@acm.org>
+
+	Reserve TREE_LANG_FLAG_3 for modules.
+	gcc/cp/
+	* cp-tree.h (DECL_CONSTRUCTION_VTABLE_P): Delete.
+	(DECL_NON_TRIVIALLY_INITIALIZED_P): Move to TREE_LANG_FLAG_6.
+	* class.c (build_ctor_vtbl_group): Don't set
+	DECL_CONSTRUCTION_VTABLE_P.
+	* decl2.c (determine_visibility_from_class): Don't check
+	DECL_CONSTRUCTION_VTABLE_P anymore.
+
 2019-09-06  Martin Liska  <mliska@suse.cz>
 
 	PR c++/91125

gcc/cp/class.c

@@ -9175,7 +9175,7 @@ build_ctor_vtbl_group (tree binfo, tree t)
      constructing the addresses of secondary vtables in the
      construction vtable group.  */
   vtbl = build_vtable (t, id, ptr_type_node);
-  DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
+
   /* Don't export construction vtables from shared libraries.  Even on
      targets that don't support hidden visibility, this tells
      can_refer_decl_in_current_unit_p not to assume that it's safe to

gcc/cp/cp-tree.h

@@ -448,12 +448,12 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       ICS_BAD_FLAG (in _CONV)
       FN_TRY_BLOCK_P (in TRY_BLOCK)
       BIND_EXPR_BODY_BLOCK (in BIND_EXPR)
-      DECL_NONTRIVIALLY_INITIALIZED_P (in VAR_DECL)
       CALL_EXPR_ORDERED_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       DECLTYPE_FOR_REF_CAPTURE (in DECLTYPE_TYPE)
       CONSTRUCTOR_C99_COMPOUND_LITERAL (in CONSTRUCTOR)
       OVL_NESTED_P (in OVERLOAD)
       LAMBDA_EXPR_INSTANTIATED (in LAMBDA_EXPR)
+      Reserved for DECL_MODULE_EXPORT (in DECL_)
    4: IDENTIFIER_MARKED (IDENTIFIER_NODEs)
       TREE_HAS_CONSTRUCTOR (in INDIRECT_REF, SAVE_EXPR, CONSTRUCTOR,
 	  CALL_EXPR, or FIELD_DECL).
@@ -466,8 +466,8 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       CALL_EXPR_REVERSE_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       CONSTRUCTOR_PLACEHOLDER_BOUNDARY (in CONSTRUCTOR)
    6: IDENTIFIER_REPO_CHOSEN (in IDENTIFIER_NODE)
-      DECL_CONSTRUCTION_VTABLE_P (in VAR_DECL)
       TYPE_MARKED_P (in _TYPE)
+      DECL_NON_TRIVIALLY_INITIALIZED_P (in VAR_DECL)
       RANGE_FOR_IVDEP (in RANGE_FOR_STMT)
       CALL_EXPR_OPERATOR_SYNTAX (in CALL_EXPR, AGGR_INIT_EXPR)
       CONSTRUCTOR_IS_DESIGNATED_INIT (in CONSTRUCTOR)
@@ -3001,7 +3001,7 @@ struct GTY(()) lang_decl {
 /* Nonzero for a VAR_DECL iff an explicit initializer was provided
    or a non-trivial constructor is called.  */
 #define DECL_NONTRIVIALLY_INITIALIZED_P(NODE)	\
-   (TREE_LANG_FLAG_3 (VAR_DECL_CHECK (NODE)))
+   (TREE_LANG_FLAG_6 (VAR_DECL_CHECK (NODE)))
 
 /* Nonzero for a VAR_DECL that was initialized with a
    constant-expression.  */
@@ -3270,12 +3270,6 @@ struct GTY(()) lang_decl {
 #define FUNCTION_RVALUE_QUALIFIED(NODE) \
   TREE_LANG_FLAG_5 (FUNC_OR_METHOD_CHECK (NODE))
 
-/* Returns 1 iff VAR_DECL is a construction virtual table.
-   DECL_VTABLE_OR_VTT_P will be true in this case and must be checked
-   before using this macro.  */
-#define DECL_CONSTRUCTION_VTABLE_P(NODE) \
-  TREE_LANG_FLAG_6 (VAR_DECL_CHECK (NODE))
-
 /* 1 iff NODE is function-local, but for types.  */
 #define LOCAL_CLASS_P(NODE)				\
   (decl_function_context (TYPE_MAIN_DECL (NODE)) != NULL_TREE)

gcc/cp/decl2.c

@@ -2713,13 +2713,8 @@ determine_visibility_from_class (tree decl, tree class_type)
   /* Give the target a chance to override the visibility associated
      with DECL.  */
   if (VAR_P (decl)
-      && (DECL_TINFO_P (decl)
-	  || (DECL_VTABLE_OR_VTT_P (decl)
-	      /* Construction virtual tables are not exported because
-		 they cannot be referred to from other object files;
-		 their name is not standardized by the ABI.  */
-	      && !DECL_CONSTRUCTION_VTABLE_P (decl)))
       && TREE_PUBLIC (decl)
+      && (DECL_TINFO_P (decl) || DECL_VTABLE_OR_VTT_P (decl))
       && !DECL_REALLY_EXTERN (decl)
       && !CLASSTYPE_VISIBILITY_SPECIFIED (class_type))
     targetm.cxx.determine_class_data_visibility (decl);