From 13175003d4aecbb1cb8f6e5707c22d318bd0f2a0 Mon Sep 17 00:00:00 2001 From: Steve Baird Date: Thu, 23 Apr 2020 14:39:55 -0700 Subject: [Ada] Implement AI12-0032 fixes for 'Old attribute accessibility 2020-06-18 Steve Baird gcc/ada/ * sem_util.adb (Object_Access_Level): Treat a 'Old attribute reference like an aggregate in determining its static accessibility level; after the evaluation of the relevant post-condition, the implicitly declared constant associated with an Old attribute reference ceases to exist. Similarly for Loop_Entry attribute. * exp_ch6.adb (Expand_Call_Helper): For an attribute reference that is expanded into a reference to an implicitly declared constant (e.g., a 'Old or 'Loop_Entry attribute), compute the dynamic accessibility level of that constant by looking at the declaration of the constant (as opposed to looking at the attribute reference). --- gcc/ada/exp_ch6.adb | 15 +++++++++++++++ gcc/ada/sem_util.adb | 12 ++++++++++++ 2 files changed, 27 insertions(+) diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb index 9a32f7e..00a0aef 100644 --- a/gcc/ada/exp_ch6.adb +++ b/gcc/ada/exp_ch6.adb @@ -3617,6 +3617,21 @@ package body Exp_Ch6 is then Prev_Orig := Prev; + -- If the actual is an attribute reference that was expanded + -- into a reference to an entity, then get accessibility level + -- from that entity. AARM 6.1.1(27.d) says "... the implicit + -- constant declaration defines the accessibility level of X'Old". + + elsif Nkind (Prev_Orig) = N_Attribute_Reference + and then Nam_In (Attribute_Name (Prev_Orig), + Name_Old, + Name_Loop_Entry) + and then Is_Entity_Name (Prev) + and then Present (Entity (Prev)) + and then Is_Object (Entity (Prev)) + then + Prev_Orig := Prev; + elsif Nkind (Prev_Orig) = N_Type_Conversion then Prev_Orig := Expression (Prev_Orig); end if; diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb index 756162e..40f34fd 100644 --- a/gcc/ada/sem_util.adb +++ b/gcc/ada/sem_util.adb @@ -24237,6 +24237,18 @@ package body Sem_Util is elsif Nkind (Orig_Obj) = N_Aggregate then return Object_Access_Level (Current_Scope); + -- Treat an Old/Loop_Entry attribute reference like an aggregate. + -- AARM 6.1.1(27.d) says "... the implicit constant declaration + -- defines the accessibility level of X'Old", so that is what + -- we are trying to implement here. + + elsif Nkind (Orig_Obj) = N_Attribute_Reference + and then Nam_In (Attribute_Name (Orig_Obj), + Name_Old, + Name_Loop_Entry) + then + return Object_Access_Level (Current_Scope); + -- Otherwise return the scope level of Standard. (If there are cases -- that fall through to this point they will be treated as having -- global accessibility for now. ???) -- cgit v1.1