From: Eric Botcazou <ebotca...@adacore.com>
This regression has been introduced by the rewrite of the finalization
machinery, which now requires a specific handling of constrained array
types with controlled component and an unconstrained first subtype.
gcc/ada/ChangeLog:
* exp_util.adb (Is_Expression_Of_Func_Return): New predicate.
(Is_Related_To_Func_Return): Call Is_Expression_Of_Func_Return.
(Remove_Side_Effects): Generate a temporary for a function call
that returns a constrained array type with controlled component
and an unconstrained first subtype.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/exp_util.adb | 55 +++++++++++++++++++++++++++++---------------
1 file changed, 37 insertions(+), 18 deletions(-)
diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
index 811942776f5..0606db4edae 100644
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -167,6 +167,9 @@ package body Exp_Util is
-- Force evaluation of bounds of a slice, which may be given by a range
-- or by a subtype indication with or without a constraint.
+ function Is_Expression_Of_Func_Return (N : Node_Id) return Boolean;
+ -- Return True if N is the expression of a function return
+
function Is_Uninitialized_Aggregate
(Exp : Node_Id;
T : Entity_Id) return Boolean;
@@ -8852,6 +8855,20 @@ package body Exp_Util is
and then Nkind (Name (N)) = N_Explicit_Dereference;
end Is_Expanded_Class_Wide_Interface_Object_Decl;
+ ----------------------------------
+ -- Is_Expression_Of_Func_Return --
+ ----------------------------------
+
+ function Is_Expression_Of_Func_Return (N : Node_Id) return Boolean is
+ Par : constant Node_Id := Parent (N);
+
+ begin
+ return Nkind (Par) = N_Simple_Return_Statement
+ or else (Nkind (Par) in N_Object_Declaration
+ | N_Object_Renaming_Declaration
+ and then Is_Return_Object (Defining_Entity (Par)));
+ end Is_Expression_Of_Func_Return;
+
------------------------------
-- Is_Finalizable_Transient --
------------------------------
@@ -9758,21 +9775,16 @@ package body Exp_Util is
function Is_Related_To_Func_Return (Id : Entity_Id) return Boolean is
Expr : constant Node_Id := Related_Expression (Id);
+
begin
-- In the case of a function with a class-wide result that returns
-- a call to a function with a specific result, we introduce a
-- type conversion for the return expression. We do not want that
-- type conversion to influence the result of this function.
- return
- Present (Expr)
- and then Nkind (Unqual_Conv (Expr)) = N_Explicit_Dereference
- and then (Nkind (Parent (Expr)) = N_Simple_Return_Statement
- or else
- (Nkind (Parent (Expr)) in N_Object_Declaration
- | N_Object_Renaming_Declaration
- and then
- Is_Return_Object (Defining_Entity (Parent (Expr)))));
+ return Present (Expr)
+ and then Nkind (Unqual_Conv (Expr)) = N_Explicit_Dereference
+ and then Is_Expression_Of_Func_Return (Expr);
end Is_Related_To_Func_Return;
--------------------------------
@@ -12949,18 +12961,25 @@ package body Exp_Util is
-- Otherwise we generate a reference to the expression
else
- -- Special processing for function calls that return a limited type.
- -- We need to build a declaration that will enable build-in-place
- -- expansion of the call. This is not done if the context is already
- -- an object declaration, to prevent infinite recursion.
+ -- Special processing for function calls with a result type that is
+ -- either BIP or a constrained array with controlled component and
+ -- an unconstrained first subtype, when the context is neither an
+ -- object declaration (to prevent infinite recursion) nor a function
+ -- return (to propagate the anonymous return object).
- -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
- -- to accommodate functions returning limited objects by reference.
+ -- We need to build an object declaration to trigger build-in-place
+ -- expansion of the call in the former case, and addition of bounds
+ -- to the object in the latter case.
- if Ada_Version >= Ada_2005
- and then Nkind (Exp) = N_Function_Call
- and then Is_Inherently_Limited_Type (Etype (Exp))
+ if Nkind (Exp) = N_Function_Call
+ and then (Is_Build_In_Place_Result_Type (Exp_Type)
+ or else (Is_Array_Type (Exp_Type)
+ and then Has_Controlled_Component (Exp_Type)
+ and then Is_Constrained (Exp_Type)
+ and then not
+ Is_Constrained (First_Subtype (Exp_Type))))
and then Nkind (Parent (Exp)) /= N_Object_Declaration
+ and then not Is_Expression_Of_Func_Return (Exp)
then
declare
Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp);
--
2.43.0
