ada: Fix bad interaction between homogeneous finalization master and BIP protocol

Dynamically-allocated objects that require finalization are attached to a
finalization master, which is of a (limited) controlled type declared in
the System.Finalization_Masters unit. Now there are two kinds of them:
homogeneous and heterogeneous; for the former, all the objects attached
to the master share the same Finalize_Address primitive whereas, for the
latter, they may have different Finalize_Address primitives.

There is a problem in this scheme with the BIP protocol, because this
protocol forwards the finalization master from callers to callees and it
does so even if the result types are distinct, so it is possible for a
homogeneous finalization master to end up containing objects with different
Finalize_Address primitives; in that case, the object attached last wins
and sets the common Finalize_Address, which is then used to finalize other
objects with unpredictable outcome (and very loud valgrind report).

Therefore, this change gets rid of homogeneous finalization masters and
also streamlines the implementation of heterogeneous ones by storing the
Finalize_Address primitive on a per object basis in the FM_Node record.

gcc/ada/

	* einfo.ads (Pending_Access_Types): Delete.
	* exp_ch3.adb (Freeze_Type.Process_Pending_Access_Types): Likewise.
	(Freeze_Type): Do not call Process_Pending_Access_Types.
	* exp_ch7.ads (Make_Set_Finalize_Address_Call): Delete.
	* exp_ch7.adb (Build_Finalization_Master.Add_Pending_Access_Type):
	Delete.
	(Build_Finalization_Master): Do not set Finalize_Address on the
	master or call Add_Pending_Access_Type.
	(Make_Set_Finalize_Address_Call): Delete.
	* gen_il-fields.ads (Opt_Field_Enum): Remove Pending_Access_Types.
	* gen_il-gen-gen_entities.adb (Type_Kind): Likewise.
	* rtsfind.ads (RE_Id): Remove RE_Set_Finalize_Address.
	(RE_Unit_Table): Likewise.
	* sem_ch3.adb (Analyze_Full_Type_Declaration): Do not deal with
	pending access types.
	* libgnat/s-finmas.ads (Attach_Unprotected): Add Finalize_Address
	second parameter.
	(Delete_Finalize_Address_Unprotected): Delete.
	(Finalize_Address): Likewise.
	(Finalize_Address_Unprotected): Likewise.
	(Is_Homogeneous): Likewise.
	(Set_Finalize_Address): Likewise.
	(Set_Finalize_Address_Unprotected): Likewise.
	(Set_Heterogeneous_Finalize_Address_Unprotected): Likewise.
	(Set_Is_Heterogeneous): Likewise.
	(FM_Node): Add Finalize_Address component.
	(Finalization_Master): Remove Is_Homogeneous and Finalize_Address
	components.
	* libgnat/s-finmas.adb: Remove with & use clauses for System.HTable.
	(Finalize_Address_Table): Delete.
	(Attach_Unprotected): Add Finalize_Address second parameter and save
	its value in the Finalize_Address field of the node.
	(Delete_Finalize_Address_Unprotected): Delete.
	(Finalize): Call Finalize_Address saved in the nodes.
	(Finalize_Address): Delete.
	(Finalize_Address_Unprotected): Likewise.
	(Hash): Likewise.
	(Is_Homogeneous): Likewise.
	(Print_Master): Adjust.
	(Set_Finalize_Address): Delete.
	(Set_Finalize_Address_Unprotected): Likewise.
	(Set_Heterogeneous_Finalize_Address_Unprotected): Likewise.
	(Set_Is_Heterogeneous): Likewise.
	* libgnat/s-stposu.adb (Finalize_Address_Table_In_Use): Likewise.
	(Allocate_Any_Controlled): Pass Fin_Address to Attach_Unprotected
	and remove obsolete processing.
	(Deallocate_Any_Controlled): Remove obsolete processing.
	(Set_Pool_Of_Subpool): Do not call Set_Is_Heterogeneous.

1 files changed, 0 insertions, 9 deletions

diff --git a/gcc/ada/einfo.ads b/gcc/ada/einfo.ads
index 3c290ef..c45c124 100644
--- a/gcc/ada/einfo.ads
+++ b/gcc/ada/einfo.ads
@@ -4008,14 +4008,6 @@ package Einfo is
 --       has unknown discriminants. A default initialization of an object of
 --       the type does not require an invariant check (AI12-0133).
 
---    Pending_Access_Types
---       Defined in all types. Set for incomplete, private, Taft-amendment
---       types, and their corresponding full views. This list contains all
---       access types, both named and anonymous, declared between the partial
---       and the full view. The list is used by the finalization machinery to
---       ensure that the finalization masters of all pending access types are
---       fully initialized when the full view is frozen.
-
 --    Predicate_Function (synthesized)
 --       Defined in all types. Set for types for which (Has_Predicates is True)
 --       and for which a predicate procedure has been built that tests that the
@@ -4995,7 +4987,6 @@ package Einfo is
    --    Esize
    --    RM_Size
    --    Alignment
-   --    Pending_Access_Types
    --    Related_Expression
    --    Current_Use_Clause
    --    Subprograms_For_Type