Fix internal error on chain of constants with -gnatc

gcc/ada/ChangeLog:
	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Constant>: In case
	the constant is not being defined, get the expression in type
	annotation mode only if its type is elementary.

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index 4e6dc84..baae58a 100644 (file)
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -667,21 +667,24 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 
       /* If we have a constant that we are not defining, get the expression it
         was defined to represent.  This is necessary to avoid generating dumb
-        elaboration code in simple cases, but we may throw it away later if it
+        elaboration code in simple cases, and we may throw it away later if it
         is not a constant.  But do not do it for dispatch tables because they
         are only referenced indirectly and we need to have a consistent view
         of the exported and of the imported declarations of the tables from
         external units for them to be properly merged in LTO mode.  Moreover
-        simply do not retrieve the expression it if it is an allocator since
+        simply do not retrieve the expression if it is an allocator because
         the designated type might still be dummy at this point.  Note that we
         invoke gnat_to_gnu_external and not gnat_to_gnu because the expression
         may contain N_Expression_With_Actions nodes and thus declarations of
-        objects from other units that we need to discard.  */
+        objects from other units that we need to discard.  Note also that we
+        need to do it even if we are only annotating types, so as to be able
+        to validate representation clauses using constants.  */
       if (!definition
          && !No_Initialization (gnat_decl)
          && !Is_Dispatch_Table_Entity (gnat_entity)
          && Present (gnat_temp = Expression (gnat_decl))
-         && Nkind (gnat_temp) != N_Allocator)
+         && Nkind (gnat_temp) != N_Allocator
+         && (Is_Elementary_Type (Etype (gnat_entity)) || !type_annotate_only))
        gnu_expr = gnat_to_gnu_external (gnat_temp);
 
       /* ... fall through ... */