===================================================================
@@ -2330,17 +2330,22 @@
end if;
-- Perform the check of 4.6(49) that prevents a null value from being
- -- passed as an actual to an access parameter. Note that the check is
- -- elided in the common cases of passing an access attribute or
+ -- passed as an actual to an access parameter. Note that the check
+ -- is elided in the common cases of passing an access attribute or
-- access parameter as an actual. Also, we currently don't enforce
-- this check for expander-generated actuals and when -gnatdj is set.
if Ada_Version >= Ada_05 then
- -- Ada 2005 (AI-231): Check null-excluding access types
+ -- Ada 2005 (AI-231): Check null-excluding access types. Note that
+ -- the intent of 6.4.1(13) is that null-exclusion checks should
+ -- not be done for 'out' parameters, even though it refers only
+ -- to constraint checks, and a null_exlusion is not a constraint.
+ -- Note that AI05-0196-1 corrects this mistake in the RM.
if Is_Access_Type (Etype (Formal))
and then Can_Never_Be_Null (Etype (Formal))
+ and then Ekind (Formal) /= E_Out_Parameter
and then Nkind (Prev) /= N_Raise_Constraint_Error
and then (Known_Null (Prev)
or else not Can_Never_Be_Null (Etype (Prev)))
@@ -2424,10 +2429,10 @@
-- since this is a left side reference. We only do this for calls
-- from the source program since we assume that compiler generated
-- calls explicitly generate any required checks. We also need it
- -- only if we are doing standard validity checks, since clearly it
- -- is not needed if validity checks are off, and in subscript
- -- validity checking mode, all indexed components are checked with
- -- a call directly from Expand_N_Indexed_Component.
+ -- only if we are doing standard validity checks, since clearly it is
+ -- not needed if validity checks are off, and in subscript validity
+ -- checking mode, all indexed components are checked with a call
+ -- directly from Expand_N_Indexed_Component.
if Comes_From_Source (N)
and then Ekind (Formal) /= E_In_Parameter
@@ -2593,11 +2598,11 @@
-- Deals with Dispatch_Call if we still have a call, before expanding
-- extra actuals since this will be done on the re-analysis of the
- -- dispatching call. Note that we do not try to shorten the actual
- -- list for a dispatching call, it would not make sense to do so.
- -- Expansion of dispatching calls is suppressed when VM_Target, because
- -- the VM back-ends directly handle the generation of dispatching
- -- calls and would have to undo any expansion to an indirect call.
+ -- dispatching call. Note that we do not try to shorten the actual list
+ -- for a dispatching call, it would not make sense to do so. Expansion
+ -- of dispatching calls is suppressed when VM_Target, because the VM
+ -- back-ends directly handle the generation of dispatching calls and
+ -- would have to undo any expansion to an indirect call.
if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
and then Present (Controlling_Argument (N))
@@ -2605,8 +2610,8 @@
if Tagged_Type_Expansion then
Expand_Dispatching_Call (N);
- -- The following return is worrisome. Is it really OK to
- -- skip all remaining processing in this procedure ???
+ -- The following return is worrisome. Is it really OK to skip all
+ -- remaining processing in this procedure ???
return;
@@ -2624,8 +2629,8 @@
-- Similarly, expand calls to RCI subprograms on which pragma
-- All_Calls_Remote applies. The rewriting will be reanalyzed
- -- later. Do this only when the call comes from source since we do
- -- not want such a rewriting to occur in expanded code.
+ -- later. Do this only when the call comes from source since we
+ -- do not want such a rewriting to occur in expanded code.
if Is_All_Remote_Call (N) then
Expand_All_Calls_Remote_Subprogram_Call (N);
@@ -2650,15 +2655,15 @@
end loop;
end if;
- -- At this point we have all the actuals, so this is the point at
- -- which the various expansion activities for actuals is carried out.
+ -- At this point we have all the actuals, so this is the point at which
+ -- the various expansion activities for actuals is carried out.
Expand_Actuals (N, Subp);
- -- If the subprogram is a renaming, or if it is inherited, replace it
- -- in the call with the name of the actual subprogram being called.
- -- If this is a dispatching call, the run-time decides what to call.
- -- The Alias attribute does not apply to entries.
+ -- If the subprogram is a renaming, or if it is inherited, replace it in
+ -- the call with the name of the actual subprogram being called. If this
+ -- is a dispatching call, the run-time decides what to call. The Alias
+ -- attribute does not apply to entries.
if Nkind (N) /= N_Entry_Call_Statement
and then No (Controlling_Argument (N))
@@ -2827,10 +2832,10 @@
if Is_Access_Protected_Subprogram_Type
(Base_Type (Etype (Prefix (Name (N)))))
then
- -- If this is a call through an access to protected operation,
- -- the prefix has the form (object'address, operation'access).
- -- Rewrite as a for other protected calls: the object is the
- -- first parameter of the list of actuals.
+ -- If this is a call through an access to protected operation, the
+ -- prefix has the form (object'address, operation'access). Rewrite
+ -- as a for other protected calls: the object is the 1st parameter
+ -- of the list of actuals.
declare
Call : Node_Id;
@@ -2905,11 +2910,11 @@
-- In the case where the intrinsic is to be processed by the back end,
-- the call to Expand_Intrinsic_Call will do nothing, which is fine,
- -- since the idea in this case is to pass the call unchanged.
- -- If the intrinsic is an inherited unchecked conversion, and the
- -- derived type is the target type of the conversion, we must retain
- -- it as the return type of the expression. Otherwise the expansion
- -- below, which uses the parent operation, will yield the wrong type.
+ -- since the idea in this case is to pass the call unchanged. If the
+ -- intrinsic is an inherited unchecked conversion, and the derived type
+ -- is the target type of the conversion, we must retain it as the return
+ -- type of the expression. Otherwise the expansion below, which uses the
+ -- parent operation, will yield the wrong type.
if Is_Intrinsic_Subprogram (Subp) then
Expand_Intrinsic_Call (N, Subp);
This patch avoids doing a null_exclusion check on 'out' parameters, which is the intent of RM-6.4.1(13). The following test should run silently. gnatmake -f -gnat05 null_excluding_formal.adb null_excluding_formal procedure Null_Excluding_Formal is type A is access all Integer; procedure P (X : out not null A) is begin X := new Integer'(123); end P; Actual : A; -- defaults to null begin P (Actual); end Null_Excluding_Formal; Tested on x86_64-pc-linux-gnu, committed on trunk 2010-09-10 Bob Duff <duff@adacore.com> * exp_ch6.adb (Expand_Call): Do not perform a null_exclusion check on 'out' parameters.