[COMMITTED 12/54] ada: Fix bogus validity check failure for FP component of array with reverse SSO

[Marc Poulhiès]

From: Eric Botcazou <ebotca...@adacore.com>

It comes from a thinko in Sem_Util.In_Reverse_Storage_Order_Object: only the
innermost enclosing composite type needs to be considered by the predicate.

gcc/ada/ChangeLog:

        * sem_util.ads (In_Reverse_Storage_Order_Object): Adjust.
        * sem_util.adb (In_Reverse_Storage_Order_Object): Rewrite.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/sem_util.adb | 34 ++++++++++------------------------
 gcc/ada/sem_util.ads |  4 ++--
 2 files changed, 12 insertions(+), 26 deletions(-)

diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index fb587ee0919..f8f18d3d48b 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -14885,34 +14885,20 @@ package body Sem_Util is
 
    function In_Reverse_Storage_Order_Object (N : Node_Id) return Boolean is
       Pref : Node_Id;
-      Btyp : Entity_Id := Empty;
+      Btyp : Entity_Id;
 
    begin
-      --  Climb up indexed components
-
-      Pref := N;
-      loop
-         case Nkind (Pref) is
-            when N_Selected_Component =>
-               Pref := Prefix (Pref);
-               exit;
-
-            when N_Indexed_Component =>
-               Pref := Prefix (Pref);
-
-            when others =>
-               Pref := Empty;
-               exit;
-         end case;
-      end loop;
-
-      if Present (Pref) then
+      if Nkind (N) in N_Indexed_Component | N_Selected_Component then
+         Pref := Prefix (N);
          Btyp := Base_Type (Etype (Pref));
-      end if;
 
-      return Present (Btyp)
-        and then (Is_Record_Type (Btyp) or else Is_Array_Type (Btyp))
-        and then Reverse_Storage_Order (Btyp);
+         return Present (Btyp)
+           and then (Is_Record_Type (Btyp) or else Is_Array_Type (Btyp))
+           and then Reverse_Storage_Order (Btyp);
+
+      else
+         return False;
+      end if;
    end In_Reverse_Storage_Order_Object;
 
    ------------------------------
diff --git a/gcc/ada/sem_util.ads b/gcc/ada/sem_util.ads
index e3349a1b595..46987bcc469 100644
--- a/gcc/ada/sem_util.ads
+++ b/gcc/ada/sem_util.ads
@@ -1756,8 +1756,8 @@ package Sem_Util is
    --  result of the enclosing function.
 
    function In_Reverse_Storage_Order_Object (N : Node_Id) return Boolean;
-   --  Returns True if N denotes a component or subcomponent in a record or
-   --  array that has Reverse_Storage_Order.
+   --  Returns True if N denotes a component in an array or a record that has
+   --  Reverse_Storage_Order.
 
    function In_Same_Declarative_Part
      (Context : Node_Id;
-- 
2.53.0