[gcc r13-385] [Ada] Accept effectively volatile components in actuals

[Pierre-Marie de Rodat <pmderodat@gcc.gnu.org>]

https://gcc.gnu.org/g:74ce1d5a6cbcf81e21b4c0eeee372df46c275df0

commit r13-385-g74ce1d5a6cbcf81e21b4c0eeee372df46c275df0
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Wed Feb 16 12:13:57 2022 +0100

    [Ada] Accept effectively volatile components in actuals
    
    In SPARK we forbid names that are effectively volatile for reading if
    they occur in actual subprogram parameters. We wrongly rejected
    references to components, which are not names in Ada.
    
    gcc/ada/
    
            * sem_res.adb (Flag_Effectively_Volatile_Objects): Ignore
            component and discriminant identifiers.

Diff:
---
 gcc/ada/sem_res.adb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb
index 4ae0835498b..4306e49ed76 100644
--- a/gcc/ada/sem_res.adb
+++ b/gcc/ada/sem_res.adb
@@ -3868,7 +3868,13 @@ package body Sem_Res is
                when N_Identifier | N_Expanded_Name =>
                   Id := Entity (N);
 
+                  --  Identifiers of components and discriminants are not names
+                  --  in the sense of Ada RM 4.1. They can only occur as a
+                  --  selector_name in selected_component or as a choice in
+                  --  component_association.
+
                   if Is_Object (Id)
+                    and then Ekind (Id) not in E_Component | E_Discriminant
                     and then Is_Effectively_Volatile_For_Reading (Id)
                     and then
                       not Is_OK_Volatile_Context (Context       => Parent (N),