When verifying that a function that is an actual of a formal package matches
the corresponding function in the corresponding actual package, functions
given by attributes must be handled specially because each of them ends up
renaming a different generated body, and we must check that the attribute
references themselves match.
No short example available.
Tested on x86_64-pc-linux-gnu, committed on trunk
2015-10-20 Ed Schonberg <schonb...@adacore.com>
* sem_ch12.adb (Same_Instantiated_Function): New predicate in
Check_Formal_Package_Instance, used to verify that the formal
and the actual of an actual package match when both are functions
given as attribute references.
Index: sem_ch12.adb
===================================================================
--- sem_ch12.adb (revision 229023)
+++ sem_ch12.adb (working copy)
@@ -5759,6 +5759,11 @@
-- same entity we may have to traverse several definitions to recover
-- the ultimate entity that they refer to.
+ function Same_Instantiated_Function (E1, E2 : Entity_Id) return Boolean;
+ -- The formal and the actual must be identical, but if both are
+ -- given by attributes they end up renaming different generated bodies,
+ -- and we must verify that the attributes themselves match.
+
function Same_Instantiated_Variable (E1, E2 : Entity_Id) return Boolean;
-- Similarly, if the formal comes from a nested formal package, the
-- actual may designate the formal through multiple renamings, which
@@ -5834,6 +5839,35 @@
end Same_Instantiated_Constant;
--------------------------------
+ -- Same_Instantiated_Function --
+ --------------------------------
+
+ function Same_Instantiated_Function
+ (E1, E2 : Entity_Id) return Boolean
+ is
+ U1, U2 : Node_Id;
+ begin
+ if Alias (E1) = Alias (E2) then
+ return True;
+
+ elsif Present (Alias (E2)) then
+ U1 := Original_Node (Unit_Declaration_Node (E1));
+ U2 := Original_Node (Unit_Declaration_Node (Alias (E2)));
+
+ return Nkind (U1) = N_Subprogram_Renaming_Declaration
+ and then Nkind (Name (U1)) = N_Attribute_Reference
+
+ and then Nkind (U2) = N_Subprogram_Renaming_Declaration
+ and then Nkind (Name (U2)) = N_Attribute_Reference
+
+ and then
+ Attribute_Name (Name (U1)) = Attribute_Name (Name (U2));
+ else
+ return False;
+ end if;
+ end Same_Instantiated_Function;
+
+ --------------------------------
-- Same_Instantiated_Variable --
--------------------------------
@@ -6050,7 +6084,8 @@
else
Check_Mismatch
- (Ekind (E2) /= Ekind (E1) or else (Alias (E1)) /= Alias (E2));
+ (Ekind (E2) /= Ekind (E1)
+ or else not Same_Instantiated_Function (E1, E2));
end if;
else
