[Ada] Redundant finalization of controlled function result

[Arnaud Charlet <charlet at adacore dot com>]

This patch removes obsolete code related to array initialization. When an array
is initialized by an aggregate, the compiler may generate a loop to initialize
all elements. If the aggregate contains controlled function calls, the loop
statements are wrapped in a block for finalization purposes. The block already
handles proper finalization of transient objects so it no longer needs the
specialized processing performed in Process_Transient_Objects.

------------
-- Source --
------------

--  types.ads

with Ada.Finalization; use Ada.Finalization;

package Types is
   type Ctrl is new Controlled with record
      Id : Natural;
   end record;

   procedure Adjust (Obj : in out Ctrl);
   procedure Finalize (Obj : in out Ctrl);
   procedure Initialize (Obj : in out Ctrl);
end Types;

--  types.adb

with Ada.Text_IO; use Ada.Text_IO;

package body Types is
   Id_Gen : Natural := 0;

   procedure Adjust (Obj : in out Ctrl) is
      New_Id : constant Natural := Obj.Id * 100;
   begin
      Put_Line ("   adj" & Obj.Id'Img & " ->" & New_Id'Img);
      Obj.Id := New_Id;
   end Adjust;

   procedure Finalize (Obj : in out Ctrl) is
   begin
      Put_Line ("   fin" & Obj.Id'Img);
   end Finalize;

   procedure Initialize (Obj : in out Ctrl) is
   begin
      Id_Gen := Id_Gen + 1;
      Obj.Id := Id_Gen;
      Put_Line ("   ini" & Obj.Id'Img);
   end Initialize;
end Types;

--  main.adb

with Types; use Types;

procedure Main is
   function Create return Ctrl is
   begin
      return Obj : Ctrl;
   end Create;

   Container : array (1 .. 2) of Ctrl := (others => Create);
begin
   null;
end Main;

----------------------------
-- Compilation and output --
----------------------------

$ gnatmake -q -gnat05 main.adb
$ ./main
   ini 1
   adj 1 -> 100
   fin 1
   adj 100 -> 10000
   fin 100
   ini 2
   adj 2 -> 200
   fin 2
   adj 200 -> 20000
   fin 200
   fin 20000
   fin 10000

Tested on x86_64-pc-linux-gnu, committed on trunk

2012-08-06  Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_ch7.adb (Process_Transient_Objects): Remove obsolete loop
	processing related to array initialization. The expansion of
	loops already contains a mechanism to detect controlled objects
	generated by expansion and introduce a block around the loop
	statements for finalization purposes.

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