The compiler would crash because it is failing at setting up the scope stack correctly for a generic instantiation of a sibling package within a child package instance. In this case, the parent instance isn't explicitly referenced and it must be found differently.
gcc/ada/ * sem_ch12.adb (Instantiate_Package_Body): Correctly find the parent instance to place on the scope stack. Tested on x86_64-pc-linux-gnu, committed on master. --- gcc/ada/sem_ch12.adb | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb index 1ea95845a16..0f2dd39b53c 100644 --- a/gcc/ada/sem_ch12.adb +++ b/gcc/ada/sem_ch12.adb @@ -12150,8 +12150,26 @@ package body Sem_Ch12 is end; -- If it is a child unit, make the parent instance (which is an - -- instance of the parent of the generic) visible. The parent - -- instance is the prefix of the name of the generic unit. + -- instance of the parent of the generic) visible. + + -- 1) The child unit's parent is an explicit parent instance (the + -- prefix of the name of the generic unit): + + -- package Child_Package is new Parent_Instance.Child_Unit; + + -- 2) The child unit's parent is an implicit parent instance (e.g. + -- when instantiating a sibling package): + + -- generic + -- package Parent.Second_Child is + -- ... + + -- generic + -- package Parent.First_Child is + -- package Sibling_Package is new Second_Child; + + -- 3) The child unit's parent is not an instance, so the scope is + -- simply the one of the unit. if Ekind (Scope (Gen_Unit)) = E_Generic_Package and then Nkind (Gen_Id) = N_Expanded_Name @@ -12161,6 +12179,17 @@ package body Sem_Ch12 is Install_Parent (Par_Ent, In_Body => True); Par_Installed := True; + elsif Ekind (Scope (Gen_Unit)) = E_Generic_Package + and then Ekind (Scope (Act_Decl_Id)) = E_Package + and then Is_Generic_Instance (Scope (Act_Decl_Id)) + then + Par_Ent := Entity + (Prefix (Name (Get_Unit_Instantiation_Node + (Scope (Act_Decl_Id))))); + Par_Vis := Is_Immediately_Visible (Par_Ent); + Install_Parent (Par_Ent, In_Body => True); + Par_Installed := True; + elsif Is_Child_Unit (Gen_Unit) then Par_Ent := Scope (Gen_Unit); Par_Vis := Is_Immediately_Visible (Par_Ent); -- 2.34.1