===================================================================
@@ -3409,7 +3409,46 @@
Generate_Reference (Orig_A, A, 'm');
elsif not Is_Overloaded (A) then
- Generate_Reference (Orig_A, A);
+ if Ekind (F) /= E_Out_Parameter then
+ Generate_Reference (Orig_A, A);
+
+ -- RM 6.4.1(12): For an out parameter that is passed by
+ -- copy, the formal parameter object is created, and:
+
+ -- * For an access type, the formal parameter is initialized
+ -- from the value of the actual, without checking that the
+ -- value satisfies any constraint, any predicate, or any
+ -- exclusion of the null value.
+
+ -- * For a scalar type that has the Default_Value aspect
+ -- specified, the formal parameter is initialized from the
+ -- value of the actual, without checking that the value
+ -- satisfies any constraint or any predicate;
+
+ -- * For a composite type with discriminants or that has
+ -- implicit initial values for any subcomponents, the
+ -- behavior is as for an in out parameter passed by copy.
+
+ -- Hence for these cases we generate the read reference now
+ -- (the write reference will be generated later by
+ -- Note_Possible_Modification).
+
+ elsif Is_By_Copy_Type (Etype (F))
+ and then
+ (Is_Access_Type (Etype (F))
+ or else
+ (Is_Scalar_Type (Etype (F))
+ and then
+ Present (Default_Aspect_Value (Etype (F))))
+ or else
+ (Is_Composite_Type (Etype (F))
+ and then
+ (Has_Discriminants (Etype (F))
+ or else
+ Is_Partially_Initialized_Type (Etype (F)))))
+ then
+ Generate_Reference (Orig_A, A);
+ end if;
end if;
end if;
end if;
The frontend was unconditionally generating a read reference for OUT parameters. After this patch the compiler generates the read reference only for those cases specified by RM 6.4.1(12). package Pkg is procedure Write (I : out Integer); procedure Update (I : in out Integer); end Pkg; package body Pkg is procedure Write (I : out Integer) is pragma Unreferenced (I); begin null; end Write; procedure Update (I : in out Integer) is pragma Unreferenced (I); begin null; end Update; end Pkg; with Pkg; procedure TEST is J : Integer := 0; begin Pkg.Write(J); -- out Pkg.Update(J); -- in out end; Command: gcc -c test.adb grep -i ^3i2 test.ali Output: 3i2 J{integer} 5m13 6m14 6r14 Tested on x86_64-pc-linux-gnu, committed on trunk 2013-02-06 Javier Miranda <miranda@adacore.com> * sem_res.adb (Resolve_Actuals): Generate a read reference for out-mode parameters in the cases specified by RM 6.4.1(12).