===================================================================
@@ -4616,22 +4616,20 @@
-- If the prefix is of an access type that is not access-to-constant,
-- then this construct is a variable reference, which means it is to
- -- be considered to have side effects if Variable_Ref is set True
- -- Exception is an access to an entity that is a constant or an
- -- in-parameter which does not come from source, and is the result
- -- of a previous removal of side-effects.
+ -- be considered to have side effects if Variable_Ref is set True.
elsif Is_Access_Type (Etype (Prefix (N)))
and then not Is_Access_Constant (Etype (Prefix (N)))
and then Variable_Ref
then
- if not Is_Entity_Name (Prefix (N)) then
- return False;
- else
- return Ekind (Entity (Prefix (N))) = E_Constant
- or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
- end if;
+ -- Exception is a prefix that is the result of a previous removal
+ -- of side-effects.
+ return Is_Entity_Name (Prefix (N))
+ and then not Comes_From_Source (Prefix (N))
+ and then Ekind (Entity (Prefix (N))) = E_Constant
+ and then Is_Internal_Name (Chars (Entity (Prefix (N))));
+
-- If the prefix is an explicit dereference then this construct is a
-- variable reference, which means it is to be considered to have
-- side effects if Variable_Ref is True.
@@ -4945,11 +4943,25 @@
-- Start of processing for Remove_Side_Effects
begin
- -- If we are side effect free already or expansion is disabled,
- -- there is nothing to do.
+ -- Handle cases in which there is nothing to do
- if Side_Effect_Free (Exp) or else not Expander_Active then
+ if not Expander_Active then
return;
+
+ -- Cannot generate temporaries if the invocation to remove side effects
+ -- was issued too early and the type of the expression is not resolved
+ -- (this happens because routines Duplicate_Subexpr_XX implicitly invoke
+ -- Remove_Side_Effects).
+
+ elsif No (Exp_Type)
+ or else Ekind (Exp_Type) = E_Access_Attribute_Type
+ then
+ return;
+
+ -- No action needed for side-effect free expressions
+
+ elsif Side_Effect_Free (Exp) then
+ return;
end if;
-- All this must not have any checks
===================================================================
@@ -8631,8 +8631,8 @@
-- Ensure that side effects in the bounds are properly handled
- Remove_Side_Effects (Low_Bound (Drange), Variable_Ref => True);
- Remove_Side_Effects (High_Bound (Drange), Variable_Ref => True);
+ Force_Evaluation (Low_Bound (Drange));
+ Force_Evaluation (High_Bound (Drange));
-- Do not apply the range check to nodes associated with the
-- frontend expansion of the dispatch table. We first check
This patch improves the removal of side effects in in-mode parameters whose type is an access type. Required because the compiler was considering side-effect free an in-mode parameter whose type is an access type. This improvement is visible compiling the following test with switch -gnatD: procedure cutdown is type root is tagged record Msg : String (1 .. 123); end record; type ext is new root with record Len : natural; end record; type root_ref is access all Root'Class; function F (X : Root_Ref) return String is Result : String := X.Msg (1 .. Ext (X.all).Len); -- [Test] begin return Result; end F; begin null; end; The previous expansion of line [Test] included: [constraint_error when cutdown__ext!(x.all).len >= 1 and then (integer(cutdown__ext!(x.all). len) > 123) "range check failed"] [subtype cutdown__f__T184b is integer range 1 .. cutdown__ext!(x.all).len] ... and the nex expansion is as follows: R184b : constant natural := cutdown__ext!(x.all).len; [constraint_error when R184b >= 1 and then (integer(R184b) > 123) "range check failed"] [subtype cutdown__f__T185b is integer range 1 .. R184b] Tested on x86_64-pc-linux-gnu, committed on trunk 2011-08-02 Javier Miranda <miranda@adacore.com> * exp_util.adb (Safe_Prefixed_Reference): Do not consider safe an in-mode parameter whose type is an access type since it can be used to modify its designated object. Enforce code that handles as safe an access type that is not access-to-constant but it is the result of a previous removal of side-effects. (Remove_Side_Effects): Minor code reorganization of cases which require no action. Done to incorporate documentation on new cases uncovered working in this ticket: no action needed if this routine was invoked too early and the nodes are not yet decorated. * sem_res.adb (Resolve_Slice): Minor code cleanup replacling two calls to routine Remove_Side_Effects by calls to Force_Evaluation since they were issued with actuals that are implicitly provided by Force_Evaluation.