https://gcc.gnu.org/g:8f5a2b59a8ed558080c41a335d44194843553c99
commit r16-1935-g8f5a2b59a8ed558080c41a335d44194843553c99
Author: Gary Dismukes <dismu...@adacore.com>
Date: Tue Jun 3 01:01:12 2025 +0000
ada: Enforce visibility of unit used as a parent instance of a child
instance
In cases involving instantiation of a generic child unit, the visibility
of the parent unit was mishandled, allowing the parent to be referenced
in another compilation unit that has visibility of the child instance
but no with_clause for the parent of the instance.
gcc/ada/ChangeLog:
* sem_ch12.adb (Install_Spec): Remove "not Is_Generic_Instance
(Par)"
in test for setting Instance_Parent_Unit. Revise comment to no
longer
say "noninstance", plus remove "???".
(Remove_Parent): Restructure if_statement to allow for both "elsif"
parts to be executed (by changing them to be separate if_statements
within an "else" part).
Diff:
---
gcc/ada/sem_ch12.adb | 74 ++++++++++++++++++++++++++--------------------------
1 file changed, 37 insertions(+), 37 deletions(-)
diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb
index 7ebf145d783e..e80aea5fe762 100644
--- a/gcc/ada/sem_ch12.adb
+++ b/gcc/ada/sem_ch12.adb
@@ -11131,13 +11131,9 @@ package body Sem_Ch12 is
begin
-- If this parent of the child instance is a top-level unit,
-- then record the unit and its visibility for later resetting in
- -- Remove_Parent. We exclude units that are generic instances, as we
- -- only want to record this information for the ultimate top-level
- -- noninstance parent (is that always correct???).
+ -- Remove_Parent.
- if Scope (Par) = Standard_Standard
- and then not Is_Generic_Instance (Par)
- then
+ if Scope (Par) = Standard_Standard then
Parent_Unit_Visible := Is_Immediately_Visible (Par);
Instance_Parent_Unit := Par;
end if;
@@ -16338,39 +16334,43 @@ package body Sem_Ch12 is
Install_Private_Declarations (P);
end if;
- -- If the ultimate parent is a top-level unit recorded in
- -- Instance_Parent_Unit, then reset its visibility to what it was
- -- before instantiation. (It's not clear what the purpose is of
- -- testing whether Scope (P) is In_Open_Scopes, but that test was
- -- present before the ultimate parent test was added.???)
-
- elsif not In_Open_Scopes (Scope (P))
- or else (P = Instance_Parent_Unit
- and then not Parent_Unit_Visible)
- then
- Set_Is_Immediately_Visible (P, False);
+ else
+ -- If the ultimate parent is a top-level unit recorded in
+ -- Instance_Parent_Unit, then reset its visibility to what
+ -- it was before instantiation. (It's not clear what the
+ -- purpose is of testing whether Scope (P) is In_Open_Scopes,
+ -- but that test was present before the ultimate parent test
+ -- was added.???)
+
+ if not In_Open_Scopes (Scope (P))
+ or else (P = Instance_Parent_Unit
+ and then not Parent_Unit_Visible)
+ then
+ Set_Is_Immediately_Visible (P, False);
+ end if;
- -- If the current scope is itself an instantiation of a generic
- -- nested within P, and we are in the private part of body of this
- -- instantiation, restore the full views of P, that were removed
- -- in End_Package_Scope above. This obscure case can occur when a
- -- subunit of a generic contains an instance of a child unit of
- -- its generic parent unit.
+ -- If the current scope is itself an instantiation of a generic
+ -- nested within P, and we are in the private part of body of
+ -- the instantiation, restore the full views of P, which were
+ -- removed in End_Package_Scope above. This obscure case can
+ -- occur when a subunit of a generic contains an instance of
+ -- a child unit of its generic parent unit.
- elsif S = Current_Scope and then Is_Generic_Instance (S)
- and then (In_Package_Body (S) or else In_Private_Part (S))
- then
- declare
- Par : constant Entity_Id :=
- Generic_Parent (Package_Specification (S));
- begin
- if Present (Par)
- and then P = Scope (Par)
- then
- Set_In_Private_Part (P);
- Install_Private_Declarations (P);
- end if;
- end;
+ if S = Current_Scope and then Is_Generic_Instance (S)
+ and then (In_Package_Body (S) or else In_Private_Part (S))
+ then
+ declare
+ Par : constant Entity_Id :=
+ Generic_Parent (Package_Specification (S));
+ begin
+ if Present (Par)
+ and then P = Scope (Par)
+ then
+ Set_In_Private_Part (P);
+ Install_Private_Declarations (P);
+ end if;
+ end;
+ end if;
end if;
end loop;
