https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124310
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ebotcazou at gcc dot gnu.org
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #2 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
I think that your program is equivalent to:
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Unchecked_Deallocation;
procedure Q is
type Rec is record
X : aliased Integer;
end record;
type Rec_Access is access all Rec;
procedure Free is new Ada.Unchecked_Deallocation (Rec, Rec_Access);
type Integer_Access is access all Integer;
O : Rec_Access := new Rec'(X => 1);
A : Integer_Access := O.X'Access;
begin
Put_Line (A.all'Image);
Free (O);
Put_Line (A.all'Image);
end;
which is perfectly legal and nevertheless has a use-after-free. That being
said, accessibility rules are arcane and their exegesis requires a significant
background. GCC's bugzilla is not the appropriate place to discuss them,
please go to https://forum.ada-lang.io instead.
