Richard Wai
Managing Director
T. 416.316.9806
> -----Original Message-----
> From: Eric Botcazou <ebotca...@adacore.com>
> Sent: March 3, 2020 3:50 PM
> To: Richard Wai <rich...@annexi-strayline.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: Re: [PATCH] Ada: gcc-interface: fixed assertion for aliased
entities
>
> > Discovered this error when attempting to allocate from a
> > Root_Storage_Pool_With_Subpools derived type. If the type is derived
> > in the current compilation unit, and Allocate is not overridden on
> > derivation (as is typically the case with
> > Root_Storage_Pool_With_Subpools), the entity for Allocate for the
> > derived type is then an alias to
> > System.Storage_Pools.Subpools.Allocate. When the allocator is built,
> > gnat_to_gnu_entity is called with definition == false for the derived
> > storage pool's allocate operation. An assertion is gnat_to_gnu_entity
> > fails in this case, since it is not a definition, and Is_Public is
> > false. If the storage pool type was instead derived in a different
> compilation unit, this assertion is not triggered since the aliased entity
has
> the Public property.
>
> We need a testcase here, we cannot relax assertions without testcases.
>
I'll have to look into this.. Any pointers? This assertion is not a language
rule assertion.
> > This patch adds an extra check in the assertion (decl.c:
> > gnat_to_gnu_entity) that the entity has the Aliased property. Also
> > included a comment that describes the special case as per the
description
> above.
>
> I don't really understand the new condition, did you forget to test
Is_Public?
>
As you see, the assertion being modified already tests for "Is_Public". So
the issue is precisely that this assertion wrongly fails for cases where the
entity is not Public. The specific case we ran into is where you have a
derived Root_Storage_Pool_With_Subpools type where Allocate (resp.
Deallocate) is inherited. If that derived type is anywhere except a package
specification, The N_Defining_Identifier for allocate for the derived
subpool will both be an alias to System.Storage_Pools.Subpools.Allocate, and
will NOT be Public. It will then cause this assertion to fail upon building
of the allocator or deallocator.
> --
> Eric Botcazou
Richard
