===================================================================
@@ -10088,10 +10088,21 @@
if Typ = Any_Type then
return;
- elsif not Ekind_In (Typ, E_Private_Type,
+ -- An invariant must apply to a private type, or appear in the
+ -- private part of a package spec and apply to a completion.
+
+ elsif Ekind_In (Typ, E_Private_Type,
E_Record_Type_With_Private,
E_Limited_Private_Type)
then
+ null;
+
+ elsif In_Private_Part (Current_Scope)
+ and then Has_Private_Declaration (Typ)
+ then
+ null;
+
+ else
Error_Pragma_Arg
("pragma% only allowed for private type", Arg1);
end if;
===================================================================
@@ -1289,11 +1289,22 @@
when Aspect_Invariant |
Aspect_Type_Invariant =>
- -- Check placement legality
+ -- Check placement legality: An invariant must apply to a
+ -- private type, or appear in the private part of a spec.
+ -- Analysis of the pragma will verify that in the private
+ -- part it applies to a completion.
- if not Nkind_In (N, N_Private_Type_Declaration,
+ if Nkind_In (N, N_Private_Type_Declaration,
N_Private_Extension_Declaration)
then
+ null;
+
+ elsif Nkind (N) = N_Full_Type_Declaration
+ and then In_Private_Part (Current_Scope)
+ then
+ null;
+
+ else
Error_Msg_N
("invariant aspect must apply to a private type", N);
end if;
The final version of the Ada 2012 RM specifies that a type invariant can be given in the private part of a package, on the completion of a private type declaration. The following must compile quietly: package Inv is type List is private; private type Length_T is new Integer; type Array_T is array (Length_T range <>) of Integer; type Array_Ptr_T is access Array_T; type List is record Length : Length_T; Item : Array_Ptr_T; end record with Type_Invariant => List.Item'First = 1 and List.Item'Last = List.Length; end Inv; Tested on x86_64-pc-linux-gnu, committed on trunk 2011-09-06 Ed Schonberg <schonberg@adacore.com> * sem_prag.adb (Analyze_Pragma, case Type_Invariant): A type invariant is allowed on a full type declaration if it is the completion of a private declarations. * sem_ch13.adb (Analyze_Aspect_Specifications): An invariant aspect is allowed on a full type declaration in the private part of a package.