Expansion of attributes Input/Output for unchecked unions didn't work,
because it looked for a No_Elist where the AST has an empty list. Now we
look for a default value of a first discriminant (because the default
values must be given either for all or for none of the discrminants).
Also, it was wrong to insert an N_Raise_Program_Error as an action and
leave the original N_Attribute_Reference node, because Gigi doesn't know
how to expand input or output attribute references. Now we rewrite the
attribute reference just like a neighbouring code which raises
Program_Error with a reason of PE_Stream_Operation_Not_Allowed.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_attr.adb (Expand_N_Attribute_Reference): Fix expansion of
attributes Input and Output for unchecked unions.
* sem_case.ads: Fix typo "disriminant" and refill comment.diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -4237,12 +4237,13 @@ package body Exp_Attr is
-- type if the type lacks default discriminant values.
if Is_Unchecked_Union (Base_Type (U_Type))
- and then No (Discriminant_Constraint (U_Type))
+ and then
+ No (Discriminant_Default_Value (First_Discriminant (U_Type)))
then
- Insert_Action (N,
+ Rewrite (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
-
+ Set_Etype (N, B_Type);
return;
end if;
@@ -5332,12 +5333,13 @@ package body Exp_Attr is
-- values.
if Is_Unchecked_Union (Base_Type (U_Type))
- and then No (Discriminant_Constraint (U_Type))
+ and then
+ No (Discriminant_Default_Value (First_Discriminant (U_Type)))
then
- Insert_Action (N,
+ Rewrite (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
-
+ Set_Etype (N, Standard_Void_Type);
return;
end if;
diff --git a/gcc/ada/sem_case.ads b/gcc/ada/sem_case.ads
--- a/gcc/ada/sem_case.ads
+++ b/gcc/ada/sem_case.ads
@@ -44,8 +44,8 @@
-- till the freeze point in this case.
-- 3. Set the Others_Discrete_Choices list for an others choice. This is
--- used in various ways, e.g. to construct the disriminant checking function
--- for the case of a variant with an others choice.
+-- used in various ways, e.g. to construct the discriminant checking
+-- function for the case of a variant with an others choice.
-- 4. In the case of static predicates, we need to expand out choices that
-- correspond to the predicate for the back end. This expansion destroys
