From: Eric Botcazou <ebotca...@adacore.com>
This is the clause about inferable discriminants in unchecked unions.
gcc/ada/
* sem_util.adb (Has_Inferable_Discriminants): In the case of a
component with a per-object constraint, also return true if the
enclosing object is not of an unchecked union type.
In the default case, remove a useless call to Base_Type.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/sem_util.adb | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index d9ea00e53cb..736751f5fae 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -12272,33 +12272,26 @@ package body Sem_Util is
begin
-- For selected components, the subtype of the selector must be a
-- constrained Unchecked_Union. If the component is subject to a
- -- per-object constraint, then the enclosing object must have inferable
- -- discriminants.
+ -- per-object constraint, then the enclosing object must either be
+ -- a regular discriminated type or must have inferable discriminants.
if Nkind (N) = N_Selected_Component then
- if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
-
- -- A small hack. If we have a per-object constrained selected
- -- component of a formal parameter, return True since we do not
- -- know the actual parameter association yet.
-
- if Prefix_Is_Formal_Parameter (N) then
- return True;
-
- -- Otherwise, check the enclosing object and the selector
-
- else
- return Has_Inferable_Discriminants (Prefix (N))
- and then Has_Inferable_Discriminants (Selector_Name (N));
- end if;
-
-- The call to Has_Inferable_Discriminants will determine whether
-- the selector has a constrained Unchecked_Union nominal type.
- else
- return Has_Inferable_Discriminants (Selector_Name (N));
+ if not Has_Inferable_Discriminants (Selector_Name (N)) then
+ return False;
end if;
+ -- A small hack. If we have a per-object constrained selected
+ -- component of a formal parameter, return True since we do not
+ -- know the actual parameter association yet.
+
+ return not Has_Per_Object_Constraint (Entity (Selector_Name (N)))
+ or else not Is_Unchecked_Union (Etype (Prefix (N)))
+ or else Has_Inferable_Discriminants (Prefix (N))
+ or else Prefix_Is_Formal_Parameter (N);
+
-- A qualified expression has inferable discriminants if its subtype
-- mark is a constrained Unchecked_Union subtype.
@@ -12310,7 +12303,7 @@ package body Sem_Util is
-- Unchecked_Union nominal subtype.
else
- return Is_Unchecked_Union (Base_Type (Etype (N)))
+ return Is_Unchecked_Union (Etype (N))
and then Is_Constrained (Etype (N));
end if;
end Has_Inferable_Discriminants;
--
2.40.0
