From db6c298d166d22cdd33761d37a1dc94ec20b6969 Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Sat, 30 May 2020 11:14:12 +0200 Subject: [PATCH] [Ada] Add warning for overlays changing scalar storage order gcc/ada/ * sem_ch13.adb (Analyze_Attribute_Definition_Clause)
: Issue an unconditional warning for an overlay that changes the scalar storage order. --- gcc/ada/sem_ch13.adb | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb index bad6a96fe5a..4bdd2cf8bd3 100644 --- a/gcc/ada/sem_ch13.adb +++ b/gcc/ada/sem_ch13.adb @@ -6075,10 +6075,10 @@ package body Sem_Ch13 is (N, U_Ent, No_Uint, O_Ent, Off); end if; - -- If the overlay changes the storage order, mark the - -- entity as being volatile to block any optimization - -- for it since the construct is not really supported - -- by the back end. + -- If the overlay changes the storage order, warn since + -- the construct is not really supported by the back end. + -- Also mark the entity as being volatile to block the + -- optimizer, even if there is no warranty on the result. if (Is_Record_Type (Etype (U_Ent)) or else Is_Array_Type (Etype (U_Ent))) @@ -6087,6 +6087,8 @@ package body Sem_Ch13 is and then Reverse_Storage_Order (Etype (U_Ent)) /= Reverse_Storage_Order (Etype (O_Ent)) then + Error_Msg_N + ("??overlay changes scalar storage order", Expr); Set_Treat_As_Volatile (U_Ent); end if; -- 2.30.2