[Ada] Work around problematic interaction with public symbol generation

2020-06-17  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* exp_attr.adb (Expand_N_Attribute_Reference) <Attribute_First>:
	Do not replace the bound for an array type if it is public.

diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
index 51cda8299eced833776bec012aeb273a2e0534b0..ea36be02100a7a27c240196a03ebaef2da7b36a1 100644 (file)
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -3424,7 +3424,14 @@ package body Exp_Attr is
          --  reference. Note that this must be in keeping with what is done
          --  for scalar types in order for range checks to be elided in loops.
 
-         elsif Is_Array_Type (Ptyp) and then Is_Constrained (Ptyp) then
+         --  However, avoid doing it if the array type is public because, in
+         --  this case, we effectively rely on the back end to create public
+         --  symbols with consistent names across units for the array bounds.
+
+         elsif Is_Array_Type (Ptyp)
+           and then Is_Constrained (Ptyp)
+           and then not Is_Public (Ptyp)
+         then
             declare
                Bnd : Node_Id;