A recent patch enforced an existing comment in Is_Effectively_Volatile
with an assertion. To satisfy this assertion, it also set the Ekind on
discriminants earlier. However, a subtle prevention of cascaded errors
in routine Enter_Name relies on the Ekind of discriminants being set
late.
This patch reverts change to setting Ekind for discriminants and instead
detects effective volatility of a discriminant by directly looking at
its type.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_ch3.adb (Process_Discriminants): Revert recent change to
location of Set_Ekind; detect effectively volatile discriminants
by their type only.diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -19977,7 +19977,6 @@ package body Sem_Ch3 is
end if;
Set_Etype (Defining_Identifier (Discr), Discr_Type);
- Set_Ekind (Defining_Identifier (Discr), E_Discriminant);
-- If a discriminant specification includes the assignment compound
-- delimiter followed by an expression, the expression is the default
@@ -20131,10 +20130,13 @@ package body Sem_Ch3 is
-- A discriminant cannot be effectively volatile (SPARK RM 7.1.3(4)).
-- This check is relevant only when SPARK_Mode is on as it is not a
- -- standard Ada legality rule.
+ -- standard Ada legality rule. The only way for a discriminant to be
+ -- effectively volatile is to have an effectively volatile type, so
+ -- we check this directly, because the Ekind of Discr might not be
+ -- set yet (to help preventing cascaded errors on derived types).
if SPARK_Mode = On
- and then Is_Effectively_Volatile (Defining_Identifier (Discr))
+ and then Is_Effectively_Volatile (Discr_Type)
then
Error_Msg_N ("discriminant cannot be volatile", Discr);
end if;
@@ -20176,6 +20178,7 @@ package body Sem_Ch3 is
Discr_Number := Uint_1;
while Present (Discr) loop
Id := Defining_Identifier (Discr);
+ Set_Ekind (Id, E_Discriminant);
Init_Component_Location (Id);
Init_Esize (Id);
Set_Discriminant_Number (Id, Discr_Number);
