Give more informative error message for by-reference types

Recent compilers enforce more strictly the RM C.6(18) clause, which says
that volatile record types are by-reference types.  This changes the typical
error message now given in these cases.

gcc/ada/
	* gcc-interface/decl.c (gnat_to_gnu_entity) <is_type>: Declare new
	constant.  Adjust error message issued by validate_size in the case
	of by-reference types.
	(validate_size): Always use the error strings passed by the caller.

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index 5cedb740a2ebbd5af490ad5da4a2f7f1a87e3ba7..d37ed3d1b52fa58b6a8f8ac0169e626ff411bbf6 100644 (file)
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -4279,6 +4279,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
      handling alignment and possible padding.  */
   if (is_type && (!gnu_decl || this_made_decl))
     {
+      const bool is_by_ref = Is_By_Reference_Type (gnat_entity);
+
       gcc_assert (!TYPE_IS_DUMMY_P (gnu_type));
 
       /* Process the attributes, if not already done.  Note that the type is
@@ -4293,15 +4295,18 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
         non-constant).  */
       if (!gnu_size && kind != E_String_Literal_Subtype)
        {
+         const char *size_s = "size for %s too small{, minimum allowed is ^}";
+         const char *type_s = is_by_ref ? "by-reference type &" : "&";
+
          if (Known_Esize (gnat_entity))
            gnu_size
              = validate_size (Esize (gnat_entity), gnu_type, gnat_entity,
-                              VAR_DECL, false, false, NULL, NULL);
+                              VAR_DECL, false, false, size_s, type_s);
          else
            gnu_size
              = validate_size (RM_Size (gnat_entity), gnu_type, gnat_entity,
                               TYPE_DECL, false, Has_Size_Clause (gnat_entity),
-                              NULL, NULL);
+                              size_s, type_s);
        }
 
       /* If a size was specified, see if we can make a new type of that size
@@ -4614,7 +4619,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
            TYPE_ALIGN_OK (gnu_type) = 1;
 
          /* Record whether the type is passed by reference.  */
-         if (Is_By_Reference_Type (gnat_entity) && !VOID_TYPE_P (gnu_type))
+         if (is_by_ref && !VOID_TYPE_P (gnu_type))
            TYPE_BY_REFERENCE_P (gnu_type) = 1;
 
          /* Record whether an alignment clause was specified.  */
@@ -9184,7 +9189,7 @@ validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object,
       char buf[128];
       const char *s;
 
-      if (kind == FIELD_DECL)
+      if (s1 && s2)
        {
          snprintf (buf, sizeof (buf), s1, s2);
          s = buf;
@@ -9193,6 +9198,7 @@ validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object,
        s = "component size for& too small{, minimum allowed is ^}";
       else
        s = "size for& too small{, minimum allowed is ^}";
+
       post_error_ne_tree (s, gnat_error_node, gnat_object, old_size);
 
       return NULL_TREE;