ada: exp_util.adb: prevent infinite loop in case of broken code

A recent commit modified exp_util.adb in order to fix the selection of
Finalize subprograms in the case of untagged objects.
This introduced regressions for GNATSAS in fixedbugs by causing
GNAT2SCIL to loop over the same type over and over in case of broken
code.
We fix this by simply checking that the loop is making progress, and if
it doesn't, assume that we're done.

gcc/ada/ChangeLog:

	* exp_util.adb (Finalize_Address): Prevent infinite loop

diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
index 2172ce75709e978cf18193b11922afa7879b36e9..80e9a8101166faeb1e85a1a8ae3b7e74edd2c2db 100644 (file)
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -6191,12 +6191,17 @@ package body Exp_Util is
 
          else
             declare
-               Root : constant Entity_Id := Underlying_Type (Root_Type (Btyp));
+               Root      : constant Entity_Id :=
+                 Underlying_Type (Root_Type (Btyp));
+               Prev_Utyp : Entity_Id := Empty;
             begin
                if Is_Protected_Type (Root) then
                   Utyp := Corresponding_Record_Type (Root);
                else
-                  while No (TSS (Utyp, TSS_Finalize_Address)) loop
+                  while No (TSS (Utyp, TSS_Finalize_Address))
+                    and then Utyp /= Prev_Utyp
+                  loop
+                     Prev_Utyp := Utyp;
                      Utyp := Underlying_Type (Base_Type (Etype (Utyp)));
                   end loop;
                end if;