[pf3gnuchains/gcc-fork.git] / gcc / ada / exp_aggr.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                             E X P _ A G G R                              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with Atree;    use Atree;
with Checks;   use Checks;
with Debug;    use Debug;
with Einfo;    use Einfo;
with Elists;   use Elists;
with Errout;   use Errout;
with Expander; use Expander;
with Exp_Util; use Exp_Util;
with Exp_Ch3;  use Exp_Ch3;
with Exp_Ch6;  use Exp_Ch6;
with Exp_Ch7;  use Exp_Ch7;
with Exp_Ch9;  use Exp_Ch9;
with Exp_Disp; use Exp_Disp;
with Exp_Tss;  use Exp_Tss;
with Fname;    use Fname;
with Freeze;   use Freeze;
with Itypes;   use Itypes;
with Lib;      use Lib;
with Namet;    use Namet;
with Nmake;    use Nmake;
with Nlists;   use Nlists;
with Opt;      use Opt;
with Restrict; use Restrict;
with Rident;   use Rident;
with Rtsfind;  use Rtsfind;
with Ttypes;   use Ttypes;
with Sem;      use Sem;
with Sem_Aggr; use Sem_Aggr;
with Sem_Aux;  use Sem_Aux;
with Sem_Ch3;  use Sem_Ch3;
with Sem_Eval; use Sem_Eval;
with Sem_Res;  use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo;    use Sinfo;
with Snames;   use Snames;
with Stand;    use Stand;
with Targparm; use Targparm;
with Tbuild;   use Tbuild;
with Uintp;    use Uintp;

package body Exp_Aggr is

   type Case_Bounds is record
     Choice_Lo   : Node_Id;
     Choice_Hi   : Node_Id;
     Choice_Node : Node_Id;
   end record;

   type Case_Table_Type is array (Nat range <>) of Case_Bounds;
   --  Table type used by Check_Case_Choices procedure

   function Has_Default_Init_Comps (N : Node_Id) return Boolean;
   --  N is an aggregate (record or array). Checks the presence of default
   --  initialization (<>) in any component (Ada 2005: AI-287).

   function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
   --  Returns true if N is an aggregate used to initialize the components
   --  of an statically allocated dispatch table.

   function Must_Slide
     (Obj_Type : Entity_Id;
      Typ      : Entity_Id) return Boolean;
   --  A static array aggregate in an object declaration can in most cases be
   --  expanded in place. The one exception is when the aggregate is given
   --  with component associations that specify different bounds from those of
   --  the type definition in the object declaration. In this pathological
   --  case the aggregate must slide, and we must introduce an intermediate
   --  temporary to hold it.
   --
   --  The same holds in an assignment to one-dimensional array of arrays,
   --  when a component may be given with bounds that differ from those of the
   --  component type.

   procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
   --  Sort the Case Table using the Lower Bound of each Choice as the key.
   --  A simple insertion sort is used since the number of choices in a case
   --  statement of variant part will usually be small and probably in near
   --  sorted order.

   ------------------------------------------------------
   -- Local subprograms for Record Aggregate Expansion --
   ------------------------------------------------------

   function Build_Record_Aggr_Code
     (N   : Node_Id;
      Typ : Entity_Id;
      Lhs : Node_Id) return List_Id;
   --  N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
   --  aggregate. Target is an expression containing the location on which the
   --  component by component assignments will take place. Returns the list of
   --  assignments plus all other adjustments needed for tagged and controlled
   --  types.

   procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
   --  N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
   --  aggregate (which can only be a record type, this procedure is only used
   --  for record types). Transform the given aggregate into a sequence of
   --  assignments performed component by component.

   procedure Expand_Record_Aggregate
     (N           : Node_Id;
      Orig_Tag    : Node_Id := Empty;
      Parent_Expr : Node_Id := Empty);
   --  This is the top level procedure for record aggregate expansion.
   --  Expansion for record aggregates needs expand aggregates for tagged
   --  record types. Specifically Expand_Record_Aggregate adds the Tag
   --  field in front of the Component_Association list that was created
   --  during resolution by Resolve_Record_Aggregate.
   --
   --    N is the record aggregate node.
   --    Orig_Tag is the value of the Tag that has to be provided for this
   --      specific aggregate. It carries the tag corresponding to the type
   --      of the outermost aggregate during the recursive expansion
   --    Parent_Expr is the ancestor part of the original extension
   --      aggregate

   function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
   --  Return true if one of the component is of a discriminated type with
   --  defaults. An aggregate for a type with mutable components must be
   --  expanded into individual assignments.

   procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
   --  If the type of the aggregate is a type extension with renamed discrimi-
   --  nants, we must initialize the hidden discriminants of the parent.
   --  Otherwise, the target object must not be initialized. The discriminants
   --  are initialized by calling the initialization procedure for the type.
   --  This is incorrect if the initialization of other components has any
   --  side effects. We restrict this call to the case where the parent type
   --  has a variant part, because this is the only case where the hidden
   --  discriminants are accessed, namely when calling discriminant checking
   --  functions of the parent type, and when applying a stream attribute to
   --  an object of the derived type.

   -----------------------------------------------------
   -- Local Subprograms for Array Aggregate Expansion --
   -----------------------------------------------------

   function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
   --  Very large static aggregates present problems to the back-end, and are
   --  transformed into assignments and loops. This function verifies that the
   --  total number of components of an aggregate is acceptable for rewriting
   --  into a purely positional static form. Aggr_Size_OK must be called before
   --  calling Flatten.
   --
   --  This function also detects and warns about one-component aggregates that
   --  appear in a non-static context. Even if the component value is static,
   --  such an aggregate must be expanded into an assignment.

   function Backend_Processing_Possible (N : Node_Id) return Boolean;
   --  This function checks if array aggregate N can be processed directly
   --  by the backend. If this is the case True is returned.

   function Build_Array_Aggr_Code
     (N           : Node_Id;
      Ctype       : Entity_Id;
      Index       : Node_Id;
      Into        : Node_Id;
      Scalar_Comp : Boolean;
      Indexes     : List_Id := No_List) return List_Id;
   --  This recursive routine returns a list of statements containing the
   --  loops and assignments that are needed for the expansion of the array
   --  aggregate N.
   --
   --    N is the (sub-)aggregate node to be expanded into code. This node has
   --    been fully analyzed, and its Etype is properly set.
   --
   --    Index is the index node corresponding to the array sub-aggregate N
   --
   --    Into is the target expression into which we are copying the aggregate.
   --    Note that this node may not have been analyzed yet, and so the Etype
   --    field may not be set.
   --
   --    Scalar_Comp is True if the component type of the aggregate is scalar
   --
   --    Indexes is the current list of expressions used to index the object we
   --    are writing into.

   procedure Convert_Array_Aggr_In_Allocator
     (Decl   : Node_Id;
      Aggr   : Node_Id;
      Target : Node_Id);
   --  If the aggregate appears within an allocator and can be expanded in
   --  place, this routine generates the individual assignments to components
   --  of the designated object. This is an optimization over the general
   --  case, where a temporary is first created on the stack and then used to
   --  construct the allocated object on the heap.

   procedure Convert_To_Positional
     (N                    : Node_Id;
      Max_Others_Replicate : Nat     := 5;
      Handle_Bit_Packed    : Boolean := False);
   --  If possible, convert named notation to positional notation. This
   --  conversion is possible only in some static cases. If the conversion is
   --  possible, then N is rewritten with the analyzed converted aggregate.
   --  The parameter Max_Others_Replicate controls the maximum number of
   --  values corresponding to an others choice that will be converted to
   --  positional notation (the default of 5 is the normal limit, and reflects
   --  the fact that normally the loop is better than a lot of separate
   --  assignments). Note that this limit gets overridden in any case if
   --  either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
   --  set. The parameter Handle_Bit_Packed is usually set False (since we do
   --  not expect the back end to handle bit packed arrays, so the normal case
   --  of conversion is pointless), but in the special case of a call from
   --  Packed_Array_Aggregate_Handled, we set this parameter to True, since
   --  these are cases we handle in there.

   --  It would seem worthwhile to have a higher default value for Max_Others_
   --  replicate, but aggregates in the compiler make this impossible: the
   --  compiler bootstrap fails if Max_Others_Replicate is greater than 25.
   --  This is unexpected ???

   procedure Expand_Array_Aggregate (N : Node_Id);
   --  This is the top-level routine to perform array aggregate expansion.
   --  N is the N_Aggregate node to be expanded.

   function Late_Expansion
     (N      : Node_Id;
      Typ    : Entity_Id;
      Target : Node_Id) return List_Id;
   --  This routine implements top-down expansion of nested aggregates. In
   --  doing so, it avoids the generation of temporaries at each level. N is a
   --  nested (record or array) aggregate that has been marked with Expansion_
   --  Delayed. Typ is the expected type of the aggregate. Target is a
   --  (duplicable) expression that will hold the result of the aggregate
   --  expansion.

   function Make_OK_Assignment_Statement
     (Sloc       : Source_Ptr;
      Name       : Node_Id;
      Expression : Node_Id) return Node_Id;
   --  This is like Make_Assignment_Statement, except that Assignment_OK
   --  is set in the left operand. All assignments built by this unit
   --  use this routine. This is needed to deal with assignments to
   --  initialized constants that are done in place.

   function Number_Of_Choices (N : Node_Id) return Nat;
   --  Returns the number of discrete choices (not including the others choice
   --  if present) contained in (sub-)aggregate N.

   function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
   --  Given an array aggregate, this function handles the case of a packed
   --  array aggregate with all constant values, where the aggregate can be
   --  evaluated at compile time. If this is possible, then N is rewritten
   --  to be its proper compile time value with all the components properly
   --  assembled. The expression is analyzed and resolved and True is
   --  returned. If this transformation is not possible, N is unchanged
   --  and False is returned

   function Safe_Slice_Assignment (N : Node_Id) return Boolean;
   --  If a slice assignment has an aggregate with a single others_choice,
   --  the assignment can be done in place even if bounds are not static,
   --  by converting it into a loop over the discrete range of the slice.

   ------------------
   -- Aggr_Size_OK --
   ------------------

   function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
      Lo   : Node_Id;
      Hi   : Node_Id;
      Indx : Node_Id;
      Siz  : Int;
      Lov  : Uint;
      Hiv  : Uint;

      --  The following constant determines the maximum size of an array
      --  aggregate produced by converting named to positional notation (e.g.
      --  from others clauses). This avoids running away with attempts to
      --  convert huge aggregates, which hit memory limits in the backend.

      --  The normal limit is 5000, but we increase this limit to 2**24 (about
      --  16 million) if Restrictions (No_Elaboration_Code) or Restrictions
      --  (No_Implicit_Loops) is specified, since in either case, we are at
      --  risk of declaring the program illegal because of this limit.

      Max_Aggr_Size : constant Nat :=
                        5000 + (2 ** 24 - 5000) *
                          Boolean'Pos
                            (Restriction_Active (No_Elaboration_Code)
                              or else
                             Restriction_Active (No_Implicit_Loops));

      function Component_Count (T : Entity_Id) return Int;
      --  The limit is applied to the total number of components that the
      --  aggregate will have, which is the number of static expressions
      --  that will appear in the flattened array. This requires a recursive
      --  computation of the number of scalar components of the structure.

      ---------------------
      -- Component_Count --
      ---------------------

      function Component_Count (T : Entity_Id) return Int is
         Res  : Int := 0;
         Comp : Entity_Id;

      begin
         if Is_Scalar_Type (T) then
            return 1;

         elsif Is_Record_Type (T) then
            Comp := First_Component (T);
            while Present (Comp) loop
               Res := Res + Component_Count (Etype (Comp));
               Next_Component (Comp);
            end loop;

            return Res;

         elsif Is_Array_Type (T) then
            declare
               Lo : constant Node_Id :=
                      Type_Low_Bound (Etype (First_Index (T)));
               Hi : constant Node_Id :=
                      Type_High_Bound (Etype (First_Index (T)));

               Siz  : constant Int := Component_Count (Component_Type (T));

            begin
               if not Compile_Time_Known_Value (Lo)
                 or else not Compile_Time_Known_Value (Hi)
               then
                  return 0;
               else
                  return
                    Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1);
               end if;
            end;

         else
            --  Can only be a null for an access type

            return 1;
         end if;
      end Component_Count;

   --  Start of processing for Aggr_Size_OK

   begin
      Siz  := Component_Count (Component_Type (Typ));

      Indx := First_Index (Typ);
      while Present (Indx) loop
         Lo  := Type_Low_Bound (Etype (Indx));
         Hi  := Type_High_Bound (Etype (Indx));

         --  Bounds need to be known at compile time

         if not Compile_Time_Known_Value (Lo)
           or else not Compile_Time_Known_Value (Hi)
         then
            return False;
         end if;

         Lov := Expr_Value (Lo);
         Hiv := Expr_Value (Hi);

         --  A flat array is always safe

         if Hiv < Lov then
            return True;
         end if;

         --  One-component aggregates are suspicious, and if the context type
         --  is an object declaration with non-static bounds it will trip gcc;
         --  such an aggregate must be expanded into a single assignment.

         if Hiv = Lov
           and then Nkind (Parent (N)) = N_Object_Declaration
         then
            declare
               Index_Type : constant Entity_Id :=
                              Etype
                                (First_Index
                                   (Etype (Defining_Identifier (Parent (N)))));
               Indx       : Node_Id;

            begin
               if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
                  or else not Compile_Time_Known_Value
                                (Type_High_Bound (Index_Type))
               then
                  if Present (Component_Associations (N)) then
                     Indx :=
                       First (Choices (First (Component_Associations (N))));
                     if Is_Entity_Name (Indx)
                       and then not Is_Type (Entity (Indx))
                     then
                        Error_Msg_N
                          ("single component aggregate in non-static context?",
                            Indx);
                        Error_Msg_N ("\maybe subtype name was meant?", Indx);
                     end if;
                  end if;

                  return False;
               end if;
            end;
         end if;

         declare
            Rng : constant Uint := Hiv - Lov + 1;

         begin
            --  Check if size is too large

            if not UI_Is_In_Int_Range (Rng) then
               return False;
            end if;

            Siz := Siz * UI_To_Int (Rng);
         end;

         if Siz <= 0
           or else Siz > Max_Aggr_Size
         then
            return False;
         end if;

         --  Bounds must be in integer range, for later array construction

         if not UI_Is_In_Int_Range (Lov)
             or else
            not UI_Is_In_Int_Range (Hiv)
         then
            return False;
         end if;

         Next_Index (Indx);
      end loop;

      return True;
   end Aggr_Size_OK;

   ---------------------------------
   -- Backend_Processing_Possible --
   ---------------------------------

   --  Backend processing by Gigi/gcc is possible only if all the following
   --  conditions are met:

   --    1. N is fully positional

   --    2. N is not a bit-packed array aggregate;

   --    3. The size of N's array type must be known at compile time. Note
   --       that this implies that the component size is also known

   --    4. The array type of N does not follow the Fortran layout convention
   --       or if it does it must be 1 dimensional.

   --    5. The array component type may not be tagged (which could necessitate
   --       reassignment of proper tags).

   --    6. The array component type must not have unaligned bit components

   --    7. None of the components of the aggregate may be bit unaligned
   --       components.

   --    8. There cannot be delayed components, since we do not know enough
   --       at this stage to know if back end processing is possible.

   --    9. There cannot be any discriminated record components, since the
   --       back end cannot handle this complex case.

   --   10. No controlled actions need to be generated for components

   --   11. For a VM back end, the array should have no aliased components

   function Backend_Processing_Possible (N : Node_Id) return Boolean is
      Typ : constant Entity_Id := Etype (N);
      --  Typ is the correct constrained array subtype of the aggregate

      function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
      --  This routine checks components of aggregate N, enforcing checks
      --  1, 7, 8, and 9. In the multi-dimensional case, these checks are
      --  performed on subaggregates. The Index value is the current index
      --  being checked in the multi-dimensional case.

      ---------------------
      -- Component_Check --
      ---------------------

      function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
         Expr : Node_Id;

      begin
         --  Checks 1: (no component associations)

         if Present (Component_Associations (N)) then
            return False;
         end if;

         --  Checks on components

         --  Recurse to check subaggregates, which may appear in qualified
         --  expressions. If delayed, the front-end will have to expand.
         --  If the component is a discriminated record, treat as non-static,
         --  as the back-end cannot handle this properly.

         Expr := First (Expressions (N));
         while Present (Expr) loop

            --  Checks 8: (no delayed components)

            if Is_Delayed_Aggregate (Expr) then
               return False;
            end if;

            --  Checks 9: (no discriminated records)

            if Present (Etype (Expr))
              and then Is_Record_Type (Etype (Expr))
              and then Has_Discriminants (Etype (Expr))
            then
               return False;
            end if;

            --  Checks 7. Component must not be bit aligned component

            if Possible_Bit_Aligned_Component (Expr) then
               return False;
            end if;

            --  Recursion to following indexes for multiple dimension case

            if Present (Next_Index (Index))
               and then not Component_Check (Expr, Next_Index (Index))
            then
               return False;
            end if;

            --  All checks for that component finished, on to next

            Next (Expr);
         end loop;

         return True;
      end Component_Check;

   --  Start of processing for Backend_Processing_Possible

   begin
      --  Checks 2 (array not bit packed) and 10 (no controlled actions)

      if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
         return False;
      end if;

      --  If component is limited, aggregate must be expanded because each
      --  component assignment must be built in place.

      if Is_Immutably_Limited_Type (Component_Type (Typ)) then
         return False;
      end if;

      --  Checks 4 (array must not be multi-dimensional Fortran case)

      if Convention (Typ) = Convention_Fortran
        and then Number_Dimensions (Typ) > 1
      then
         return False;
      end if;

      --  Checks 3 (size of array must be known at compile time)

      if not Size_Known_At_Compile_Time (Typ) then
         return False;
      end if;

      --  Checks on components

      if not Component_Check (N, First_Index (Typ)) then
         return False;
      end if;

      --  Checks 5 (if the component type is tagged, then we may need to do
      --    tag adjustments. Perhaps this should be refined to check for any
      --    component associations that actually need tag adjustment, similar
      --    to the test in Component_Not_OK_For_Backend for record aggregates
      --    with tagged components, but not clear whether it's worthwhile ???;
      --    in the case of the JVM, object tags are handled implicitly)

      if Is_Tagged_Type (Component_Type (Typ))
        and then Tagged_Type_Expansion
      then
         return False;
      end if;

      --  Checks 6 (component type must not have bit aligned components)

      if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
         return False;
      end if;

      --  Checks 11: Array aggregates with aliased components are currently
      --  not well supported by the VM backend; disable temporarily this
      --  backend processing until it is definitely supported.

      if VM_Target /= No_VM
        and then Has_Aliased_Components (Base_Type (Typ))
      then
         return False;
      end if;

      --  Backend processing is possible

      Set_Size_Known_At_Compile_Time (Etype (N), True);
      return True;
   end Backend_Processing_Possible;

   ---------------------------
   -- Build_Array_Aggr_Code --
   ---------------------------

   --  The code that we generate from a one dimensional aggregate is

   --  1. If the sub-aggregate contains discrete choices we

   --     (a) Sort the discrete choices

   --     (b) Otherwise for each discrete choice that specifies a range we
   --         emit a loop. If a range specifies a maximum of three values, or
   --         we are dealing with an expression we emit a sequence of
   --         assignments instead of a loop.

   --     (c) Generate the remaining loops to cover the others choice if any

   --  2. If the aggregate contains positional elements we

   --     (a) translate the positional elements in a series of assignments

   --     (b) Generate a final loop to cover the others choice if any.
   --         Note that this final loop has to be a while loop since the case

   --             L : Integer := Integer'Last;
   --             H : Integer := Integer'Last;
   --             A : array (L .. H) := (1, others =>0);

   --         cannot be handled by a for loop. Thus for the following

   --             array (L .. H) := (.. positional elements.., others =>E);

   --         we always generate something like:

   --             J : Index_Type := Index_Of_Last_Positional_Element;
   --             while J < H loop
   --                J := Index_Base'Succ (J)
   --                Tmp (J) := E;
   --             end loop;

   function Build_Array_Aggr_Code
     (N           : Node_Id;
      Ctype       : Entity_Id;
      Index       : Node_Id;
      Into        : Node_Id;
      Scalar_Comp : Boolean;
      Indexes     : List_Id := No_List) return List_Id
   is
      Loc          : constant Source_Ptr := Sloc (N);
      Index_Base   : constant Entity_Id  := Base_Type (Etype (Index));
      Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
      Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);

      function Add (Val : Int; To : Node_Id) return Node_Id;
      --  Returns an expression where Val is added to expression To, unless
      --  To+Val is provably out of To's base type range. To must be an
      --  already analyzed expression.

      function Empty_Range (L, H : Node_Id) return Boolean;
      --  Returns True if the range defined by L .. H is certainly empty

      function Equal (L, H : Node_Id) return Boolean;
      --  Returns True if L = H for sure

      function Index_Base_Name return Node_Id;
      --  Returns a new reference to the index type name

      function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id;
      --  Ind must be a side-effect free expression. If the input aggregate
      --  N to Build_Loop contains no sub-aggregates, then this function
      --  returns the assignment statement:
      --
      --     Into (Indexes, Ind) := Expr;
      --
      --  Otherwise we call Build_Code recursively
      --
      --  Ada 2005 (AI-287): In case of default initialized component, Expr
      --  is empty and we generate a call to the corresponding IP subprogram.

      function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
      --  Nodes L and H must be side-effect free expressions.
      --  If the input aggregate N to Build_Loop contains no sub-aggregates,
      --  This routine returns the for loop statement
      --
      --     for J in Index_Base'(L) .. Index_Base'(H) loop
      --        Into (Indexes, J) := Expr;
      --     end loop;
      --
      --  Otherwise we call Build_Code recursively.
      --  As an optimization if the loop covers 3 or less scalar elements we
      --  generate a sequence of assignments.

      function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
      --  Nodes L and H must be side-effect free expressions.
      --  If the input aggregate N to Build_Loop contains no sub-aggregates,
      --  This routine returns the while loop statement
      --
      --     J : Index_Base := L;
      --     while J < H loop
      --        J := Index_Base'Succ (J);
      --        Into (Indexes, J) := Expr;
      --     end loop;
      --
      --  Otherwise we call Build_Code recursively

      function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
      function Local_Expr_Value               (E : Node_Id) return Uint;
      --  These two Local routines are used to replace the corresponding ones
      --  in sem_eval because while processing the bounds of an aggregate with
      --  discrete choices whose index type is an enumeration, we build static
      --  expressions not recognized by Compile_Time_Known_Value as such since
      --  they have not yet been analyzed and resolved. All the expressions in
      --  question are things like Index_Base_Name'Val (Const) which we can
      --  easily recognize as being constant.

      ---------
      -- Add --
      ---------

      function Add (Val : Int; To : Node_Id) return Node_Id is
         Expr_Pos : Node_Id;
         Expr     : Node_Id;
         To_Pos   : Node_Id;
         U_To     : Uint;
         U_Val    : constant Uint := UI_From_Int (Val);

      begin
         --  Note: do not try to optimize the case of Val = 0, because
         --  we need to build a new node with the proper Sloc value anyway.

         --  First test if we can do constant folding

         if Local_Compile_Time_Known_Value (To) then
            U_To := Local_Expr_Value (To) + Val;

            --  Determine if our constant is outside the range of the index.
            --  If so return an Empty node. This empty node will be caught
            --  by Empty_Range below.

            if Compile_Time_Known_Value (Index_Base_L)
              and then U_To < Expr_Value (Index_Base_L)
            then
               return Empty;

            elsif Compile_Time_Known_Value (Index_Base_H)
              and then U_To > Expr_Value (Index_Base_H)
            then
               return Empty;
            end if;

            Expr_Pos := Make_Integer_Literal (Loc, U_To);
            Set_Is_Static_Expression (Expr_Pos);

            if not Is_Enumeration_Type (Index_Base) then
               Expr := Expr_Pos;

            --  If we are dealing with enumeration return
            --     Index_Base'Val (Expr_Pos)

            else
               Expr :=
                 Make_Attribute_Reference
                   (Loc,
                    Prefix         => Index_Base_Name,
                    Attribute_Name => Name_Val,
                    Expressions    => New_List (Expr_Pos));
            end if;

            return Expr;
         end if;

         --  If we are here no constant folding possible

         if not Is_Enumeration_Type (Index_Base) then
            Expr :=
              Make_Op_Add (Loc,
                           Left_Opnd  => Duplicate_Subexpr (To),
                           Right_Opnd => Make_Integer_Literal (Loc, U_Val));

         --  If we are dealing with enumeration return
         --    Index_Base'Val (Index_Base'Pos (To) + Val)

         else
            To_Pos :=
              Make_Attribute_Reference
                (Loc,
                 Prefix         => Index_Base_Name,
                 Attribute_Name => Name_Pos,
                 Expressions    => New_List (Duplicate_Subexpr (To)));

            Expr_Pos :=
              Make_Op_Add (Loc,
                           Left_Opnd  => To_Pos,
                           Right_Opnd => Make_Integer_Literal (Loc, U_Val));

            Expr :=
              Make_Attribute_Reference
                (Loc,
                 Prefix         => Index_Base_Name,
                 Attribute_Name => Name_Val,
                 Expressions    => New_List (Expr_Pos));
         end if;

         return Expr;
      end Add;

      -----------------
      -- Empty_Range --
      -----------------

      function Empty_Range (L, H : Node_Id) return Boolean is
         Is_Empty : Boolean := False;
         Low      : Node_Id;
         High     : Node_Id;

      begin
         --  First check if L or H were already detected as overflowing the
         --  index base range type by function Add above. If this is so Add
         --  returns the empty node.

         if No (L) or else No (H) then
            return True;
         end if;

         for J in 1 .. 3 loop
            case J is

               --  L > H    range is empty

               when 1 =>
                  Low  := L;
                  High := H;

               --  B_L > H  range must be empty

               when 2 =>
                  Low  := Index_Base_L;
                  High := H;

               --  L > B_H  range must be empty

               when 3 =>
                  Low  := L;
                  High := Index_Base_H;
            end case;

            if Local_Compile_Time_Known_Value (Low)
              and then Local_Compile_Time_Known_Value (High)
            then
               Is_Empty :=
                 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
            end if;

            exit when Is_Empty;
         end loop;

         return Is_Empty;
      end Empty_Range;

      -----------
      -- Equal --
      -----------

      function Equal (L, H : Node_Id) return Boolean is
      begin
         if L = H then
            return True;

         elsif Local_Compile_Time_Known_Value (L)
           and then Local_Compile_Time_Known_Value (H)
         then
            return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
         end if;

         return False;
      end Equal;

      ----------------
      -- Gen_Assign --
      ----------------

      function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is
         L : constant List_Id := New_List;
         A : Node_Id;

         New_Indexes  : List_Id;
         Indexed_Comp : Node_Id;
         Expr_Q       : Node_Id;
         Comp_Type    : Entity_Id := Empty;

         function Add_Loop_Actions (Lis : List_Id) return List_Id;
         --  Collect insert_actions generated in the construction of a
         --  loop, and prepend them to the sequence of assignments to
         --  complete the eventual body of the loop.

         ----------------------
         -- Add_Loop_Actions --
         ----------------------

         function Add_Loop_Actions (Lis : List_Id) return List_Id is
            Res : List_Id;

         begin
            --  Ada 2005 (AI-287): Do nothing else in case of default
            --  initialized component.

            if No (Expr) then
               return Lis;

            elsif Nkind (Parent (Expr)) = N_Component_Association
              and then Present (Loop_Actions (Parent (Expr)))
            then
               Append_List (Lis, Loop_Actions (Parent (Expr)));
               Res := Loop_Actions (Parent (Expr));
               Set_Loop_Actions (Parent (Expr), No_List);
               return Res;

            else
               return Lis;
            end if;
         end Add_Loop_Actions;

      --  Start of processing for Gen_Assign

      begin
         if No (Indexes) then
            New_Indexes := New_List;
         else
            New_Indexes := New_Copy_List_Tree (Indexes);
         end if;

         Append_To (New_Indexes, Ind);

         if Present (Next_Index (Index)) then
            return
              Add_Loop_Actions (
                Build_Array_Aggr_Code
                  (N           => Expr,
                   Ctype       => Ctype,
                   Index       => Next_Index (Index),
                   Into        => Into,
                   Scalar_Comp => Scalar_Comp,
                   Indexes     => New_Indexes));
         end if;

         --  If we get here then we are at a bottom-level (sub-)aggregate

         Indexed_Comp :=
           Checks_Off
             (Make_Indexed_Component (Loc,
                Prefix      => New_Copy_Tree (Into),
                Expressions => New_Indexes));

         Set_Assignment_OK (Indexed_Comp);

         --  Ada 2005 (AI-287): In case of default initialized component, Expr
         --  is not present (and therefore we also initialize Expr_Q to empty).

         if No (Expr) then
            Expr_Q := Empty;
         elsif Nkind (Expr) = N_Qualified_Expression then
            Expr_Q := Expression (Expr);
         else
            Expr_Q := Expr;
         end if;

         if Present (Etype (N))
           and then Etype (N) /= Any_Composite
         then
            Comp_Type := Component_Type (Etype (N));
            pragma Assert (Comp_Type = Ctype); --  AI-287

         elsif Present (Next (First (New_Indexes))) then

            --  Ada 2005 (AI-287): Do nothing in case of default initialized
            --  component because we have received the component type in
            --  the formal parameter Ctype.

            --  ??? Some assert pragmas have been added to check if this new
            --      formal can be used to replace this code in all cases.

            if Present (Expr) then

               --  This is a multidimensional array. Recover the component
               --  type from the outermost aggregate, because subaggregates
               --  do not have an assigned type.

               declare
                  P : Node_Id;

               begin
                  P := Parent (Expr);
                  while Present (P) loop
                     if Nkind (P) = N_Aggregate
                       and then Present (Etype (P))
                     then
                        Comp_Type := Component_Type (Etype (P));
                        exit;

                     else
                        P := Parent (P);
                     end if;
                  end loop;

                  pragma Assert (Comp_Type = Ctype); --  AI-287
               end;
            end if;
         end if;

         --  Ada 2005 (AI-287): We only analyze the expression in case of non-
         --  default initialized components (otherwise Expr_Q is not present).

         if Present (Expr_Q)
           and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
         then
            --  At this stage the Expression may not have been analyzed yet
            --  because the array aggregate code has not been updated to use
            --  the Expansion_Delayed flag and avoid analysis altogether to
            --  solve the same problem (see Resolve_Aggr_Expr). So let us do
            --  the analysis of non-array aggregates now in order to get the
            --  value of Expansion_Delayed flag for the inner aggregate ???

            if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then
               Analyze_And_Resolve (Expr_Q, Comp_Type);
            end if;

            if Is_Delayed_Aggregate (Expr_Q) then

               --  This is either a subaggregate of a multidimensional array,
               --  or a component of an array type whose component type is
               --  also an array. In the latter case, the expression may have
               --  component associations that provide different bounds from
               --  those of the component type, and sliding must occur. Instead
               --  of decomposing the current aggregate assignment, force the
               --  re-analysis of the assignment, so that a temporary will be
               --  generated in the usual fashion, and sliding will take place.

               if Nkind (Parent (N)) = N_Assignment_Statement
                 and then Is_Array_Type (Comp_Type)
                 and then Present (Component_Associations (Expr_Q))
                 and then Must_Slide (Comp_Type, Etype (Expr_Q))
               then
                  Set_Expansion_Delayed (Expr_Q, False);
                  Set_Analyzed (Expr_Q, False);

               else
                  return
                    Add_Loop_Actions (
                      Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
               end if;
            end if;
         end if;

         --  Ada 2005 (AI-287): In case of default initialized component, call
         --  the initialization subprogram associated with the component type.
         --  If the component type is an access type, add an explicit null
         --  assignment, because for the back-end there is an initialization
         --  present for the whole aggregate, and no default initialization
         --  will take place.

         --  In addition, if the component type is controlled, we must call
         --  its Initialize procedure explicitly, because there is no explicit
         --  object creation that will invoke it otherwise.

         if No (Expr) then
            if Present (Base_Init_Proc (Base_Type (Ctype)))
              or else Has_Task (Base_Type (Ctype))
            then
               Append_List_To (L,
                 Build_Initialization_Call (Loc,
                   Id_Ref            => Indexed_Comp,
                   Typ               => Ctype,
                   With_Default_Init => True));

            elsif Is_Access_Type (Ctype) then
               Append_To (L,
                  Make_Assignment_Statement (Loc,
                     Name => Indexed_Comp,
                     Expression => Make_Null (Loc)));
            end if;

            if Needs_Finalization (Ctype) then
               Append_To (L,
                 Make_Init_Call (
                   Obj_Ref => New_Copy_Tree (Indexed_Comp),
                   Typ     => Ctype));
            end if;

         else
            --  Now generate the assignment with no associated controlled
            --  actions since the target of the assignment may not have been
            --  initialized, it is not possible to Finalize it as expected by
            --  normal controlled assignment. The rest of the controlled
            --  actions are done manually with the proper finalization list
            --  coming from the context.

            A :=
              Make_OK_Assignment_Statement (Loc,
                Name       => Indexed_Comp,
                Expression => New_Copy_Tree (Expr));

            if Present (Comp_Type) and then Needs_Finalization (Comp_Type) then
               Set_No_Ctrl_Actions (A);

               --  If this is an aggregate for an array of arrays, each
               --  sub-aggregate will be expanded as well, and even with
               --  No_Ctrl_Actions the assignments of inner components will
               --  require attachment in their assignments to temporaries.
               --  These temporaries must be finalized for each subaggregate,
               --  to prevent multiple attachments of the same temporary
               --  location to same finalization chain (and consequently
               --  circular lists). To ensure that finalization takes place
               --  for each subaggregate we wrap the assignment in a block.

               if Is_Array_Type (Comp_Type)
                 and then Nkind (Expr) = N_Aggregate
               then
                  A :=
                    Make_Block_Statement (Loc,
                      Handled_Statement_Sequence =>
                        Make_Handled_Sequence_Of_Statements (Loc,
                           Statements => New_List (A)));
               end if;
            end if;

            Append_To (L, A);

            --  Adjust the tag if tagged (because of possible view
            --  conversions), unless compiling for a VM where
            --  tags are implicit.

            if Present (Comp_Type)
              and then Is_Tagged_Type (Comp_Type)
              and then Tagged_Type_Expansion
            then
               declare
                  Full_Typ : constant Entity_Id := Underlying_Type (Comp_Type);

               begin
                  A :=
                    Make_OK_Assignment_Statement (Loc,
                      Name =>
                        Make_Selected_Component (Loc,
                          Prefix =>  New_Copy_Tree (Indexed_Comp),
                          Selector_Name =>
                            New_Reference_To
                              (First_Tag_Component (Full_Typ), Loc)),

                      Expression =>
                        Unchecked_Convert_To (RTE (RE_Tag),
                          New_Reference_To
                            (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
                             Loc)));

                  Append_To (L, A);
               end;
            end if;

            --  Adjust and attach the component to the proper final list, which
            --  can be the controller of the outer record object or the final
            --  list associated with the scope.

            --  If the component is itself an array of controlled types, whose
            --  value is given by a sub-aggregate, then the attach calls have
            --  been generated when individual subcomponent are assigned, and
            --  must not be done again to prevent malformed finalization chains
            --  (see comments above, concerning the creation of a block to hold
            --  inner finalization actions).

            if Present (Comp_Type)
              and then Needs_Finalization (Comp_Type)
              and then not Is_Limited_Type (Comp_Type)
              and then not
                (Is_Array_Type (Comp_Type)
                   and then Is_Controlled (Component_Type (Comp_Type))
                   and then Nkind (Expr) = N_Aggregate)
            then
               Append_To (L,
                 Make_Adjust_Call (
                   Obj_Ref => New_Copy_Tree (Indexed_Comp),
                   Typ     => Comp_Type));
            end if;
         end if;

         return Add_Loop_Actions (L);
      end Gen_Assign;

      --------------
      -- Gen_Loop --
      --------------

      function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
         L_J : Node_Id;

         L_L : Node_Id;
         --  Index_Base'(L)

         L_H : Node_Id;
         --  Index_Base'(H)

         L_Range : Node_Id;
         --  Index_Base'(L) .. Index_Base'(H)

         L_Iteration_Scheme : Node_Id;
         --  L_J in Index_Base'(L) .. Index_Base'(H)

         L_Body : List_Id;
         --  The statements to execute in the loop

         S : constant List_Id := New_List;
         --  List of statements

         Tcopy : Node_Id;
         --  Copy of expression tree, used for checking purposes

      begin
         --  If loop bounds define an empty range return the null statement

         if Empty_Range (L, H) then
            Append_To (S, Make_Null_Statement (Loc));

            --  Ada 2005 (AI-287): Nothing else need to be done in case of
            --  default initialized component.

            if No (Expr) then
               null;

            else
               --  The expression must be type-checked even though no component
               --  of the aggregate will have this value. This is done only for
               --  actual components of the array, not for subaggregates. Do
               --  the check on a copy, because the expression may be shared
               --  among several choices, some of which might be non-null.

               if Present (Etype (N))
                 and then Is_Array_Type (Etype (N))
                 and then No (Next_Index (Index))
               then
                  Expander_Mode_Save_And_Set (False);
                  Tcopy := New_Copy_Tree (Expr);
                  Set_Parent (Tcopy, N);
                  Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
                  Expander_Mode_Restore;
               end if;
            end if;

            return S;

         --  If loop bounds are the same then generate an assignment

         elsif Equal (L, H) then
            return Gen_Assign (New_Copy_Tree (L), Expr);

         --  If H - L <= 2 then generate a sequence of assignments when we are
         --  processing the bottom most aggregate and it contains scalar
         --  components.

         elsif No (Next_Index (Index))
           and then Scalar_Comp
           and then Local_Compile_Time_Known_Value (L)
           and then Local_Compile_Time_Known_Value (H)
           and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
         then

            Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
            Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));

            if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
               Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
            end if;

            return S;
         end if;

         --  Otherwise construct the loop, starting with the loop index L_J

         L_J := Make_Temporary (Loc, 'J', L);

         --  Construct "L .. H" in Index_Base. We use a qualified expression
         --  for the bound to convert to the index base, but we don't need
         --  to do that if we already have the base type at hand.

         if Etype (L) = Index_Base then
            L_L := L;
         else
            L_L :=
              Make_Qualified_Expression (Loc,
                Subtype_Mark => Index_Base_Name,
                Expression   => L);
         end if;

         if Etype (H) = Index_Base then
            L_H := H;
         else
            L_H :=
              Make_Qualified_Expression (Loc,
                Subtype_Mark => Index_Base_Name,
                Expression   => H);
         end if;

         L_Range :=
           Make_Range (Loc,
             Low_Bound => L_L,
             High_Bound => L_H);

         --  Construct "for L_J in Index_Base range L .. H"

         L_Iteration_Scheme :=
           Make_Iteration_Scheme
             (Loc,
              Loop_Parameter_Specification =>
                Make_Loop_Parameter_Specification
                  (Loc,
                   Defining_Identifier         => L_J,
                   Discrete_Subtype_Definition => L_Range));

         --  Construct the statements to execute in the loop body

         L_Body := Gen_Assign (New_Reference_To (L_J, Loc), Expr);

         --  Construct the final loop

         Append_To (S, Make_Implicit_Loop_Statement
                         (Node             => N,
                          Identifier       => Empty,
                          Iteration_Scheme => L_Iteration_Scheme,
                          Statements       => L_Body));

         --  A small optimization: if the aggregate is initialized with a box
         --  and the component type has no initialization procedure, remove the
         --  useless empty loop.

         if Nkind (First (S)) = N_Loop_Statement
           and then Is_Empty_List (Statements (First (S)))
         then
            return New_List (Make_Null_Statement (Loc));
         else
            return S;
         end if;
      end Gen_Loop;

      ---------------
      -- Gen_While --
      ---------------

      --  The code built is

      --     W_J : Index_Base := L;
      --     while W_J < H loop
      --        W_J := Index_Base'Succ (W);
      --        L_Body;
      --     end loop;

      function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
         W_J : Node_Id;

         W_Decl : Node_Id;
         --  W_J : Base_Type := L;

         W_Iteration_Scheme : Node_Id;
         --  while W_J < H

         W_Index_Succ : Node_Id;
         --  Index_Base'Succ (J)

         W_Increment : Node_Id;
         --  W_J := Index_Base'Succ (W)

         W_Body : constant List_Id := New_List;
         --  The statements to execute in the loop

         S : constant List_Id := New_List;
         --  list of statement

      begin
         --  If loop bounds define an empty range or are equal return null

         if Empty_Range (L, H) or else Equal (L, H) then
            Append_To (S, Make_Null_Statement (Loc));
            return S;
         end if;

         --  Build the decl of W_J

         W_J    := Make_Temporary (Loc, 'J', L);
         W_Decl :=
           Make_Object_Declaration
             (Loc,
              Defining_Identifier => W_J,
              Object_Definition   => Index_Base_Name,
              Expression          => L);

         --  Theoretically we should do a New_Copy_Tree (L) here, but we know
         --  that in this particular case L is a fresh Expr generated by
         --  Add which we are the only ones to use.

         Append_To (S, W_Decl);

         --  Construct " while W_J < H"

         W_Iteration_Scheme :=
           Make_Iteration_Scheme
             (Loc,
              Condition => Make_Op_Lt
                             (Loc,
                              Left_Opnd  => New_Reference_To (W_J, Loc),
                              Right_Opnd => New_Copy_Tree (H)));

         --  Construct the statements to execute in the loop body

         W_Index_Succ :=
           Make_Attribute_Reference
             (Loc,
              Prefix         => Index_Base_Name,
              Attribute_Name => Name_Succ,
              Expressions    => New_List (New_Reference_To (W_J, Loc)));

         W_Increment  :=
           Make_OK_Assignment_Statement
             (Loc,
              Name       => New_Reference_To (W_J, Loc),
              Expression => W_Index_Succ);

         Append_To (W_Body, W_Increment);
         Append_List_To (W_Body,
           Gen_Assign (New_Reference_To (W_J, Loc), Expr));

         --  Construct the final loop

         Append_To (S, Make_Implicit_Loop_Statement
                         (Node             => N,
                          Identifier       => Empty,
                          Iteration_Scheme => W_Iteration_Scheme,
                          Statements       => W_Body));

         return S;
      end Gen_While;

      ---------------------
      -- Index_Base_Name --
      ---------------------

      function Index_Base_Name return Node_Id is
      begin
         return New_Reference_To (Index_Base, Sloc (N));
      end Index_Base_Name;

      ------------------------------------
      -- Local_Compile_Time_Known_Value --
      ------------------------------------

      function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
      begin
         return Compile_Time_Known_Value (E)
           or else
             (Nkind (E) = N_Attribute_Reference
               and then Attribute_Name (E) = Name_Val
               and then Compile_Time_Known_Value (First (Expressions (E))));
      end Local_Compile_Time_Known_Value;

      ----------------------
      -- Local_Expr_Value --
      ----------------------

      function Local_Expr_Value (E : Node_Id) return Uint is
      begin
         if Compile_Time_Known_Value (E) then
            return Expr_Value (E);
         else
            return Expr_Value (First (Expressions (E)));
         end if;
      end Local_Expr_Value;

      --  Build_Array_Aggr_Code Variables

      Assoc  : Node_Id;
      Choice : Node_Id;
      Expr   : Node_Id;
      Typ    : Entity_Id;

      Others_Expr        : Node_Id := Empty;
      Others_Box_Present : Boolean := False;

      Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
      Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
      --  The aggregate bounds of this specific sub-aggregate. Note that if
      --  the code generated by Build_Array_Aggr_Code is executed then these
      --  bounds are OK. Otherwise a Constraint_Error would have been raised.

      Aggr_Low  : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
      Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
      --  After Duplicate_Subexpr these are side-effect free

      Low        : Node_Id;
      High       : Node_Id;

      Nb_Choices : Nat := 0;
      Table      : Case_Table_Type (1 .. Number_Of_Choices (N));
      --  Used to sort all the different choice values

      Nb_Elements : Int;
      --  Number of elements in the positional aggregate

      New_Code : constant List_Id := New_List;

   --  Start of processing for Build_Array_Aggr_Code

   begin
      --  First before we start, a special case. if we have a bit packed
      --  array represented as a modular type, then clear the value to
      --  zero first, to ensure that unused bits are properly cleared.

      Typ := Etype (N);

      if Present (Typ)
        and then Is_Bit_Packed_Array (Typ)
        and then Is_Modular_Integer_Type (Packed_Array_Type (Typ))
      then
         Append_To (New_Code,
           Make_Assignment_Statement (Loc,
             Name => New_Copy_Tree (Into),
             Expression =>
               Unchecked_Convert_To (Typ,
                 Make_Integer_Literal (Loc, Uint_0))));
      end if;

      --  If the component type contains tasks, we need to build a Master
      --  entity in the current scope, because it will be needed if build-
      --  in-place functions are called in the expanded code.

      if Nkind (Parent (N)) = N_Object_Declaration
        and then Has_Task (Typ)
      then
         Build_Master_Entity (Defining_Identifier (Parent (N)));
      end if;

      --  STEP 1: Process component associations

      --  For those associations that may generate a loop, initialize
      --  Loop_Actions to collect inserted actions that may be crated.

      --  Skip this if no component associations

      if No (Expressions (N)) then

         --  STEP 1 (a): Sort the discrete choices

         Assoc := First (Component_Associations (N));
         while Present (Assoc) loop
            Choice := First (Choices (Assoc));
            while Present (Choice) loop
               if Nkind (Choice) = N_Others_Choice then
                  Set_Loop_Actions (Assoc, New_List);

                  if Box_Present (Assoc) then
                     Others_Box_Present := True;
                  else
                     Others_Expr := Expression (Assoc);
                  end if;
                  exit;
               end if;

               Get_Index_Bounds (Choice, Low, High);

               if Low /= High then
                  Set_Loop_Actions (Assoc, New_List);
               end if;

               Nb_Choices := Nb_Choices + 1;
               if Box_Present (Assoc) then
                  Table (Nb_Choices) := (Choice_Lo   => Low,
                                         Choice_Hi   => High,
                                         Choice_Node => Empty);
               else
                  Table (Nb_Choices) := (Choice_Lo   => Low,
                                         Choice_Hi   => High,
                                         Choice_Node => Expression (Assoc));
               end if;
               Next (Choice);
            end loop;

            Next (Assoc);
         end loop;

         --  If there is more than one set of choices these must be static
         --  and we can therefore sort them. Remember that Nb_Choices does not
         --  account for an others choice.

         if Nb_Choices > 1 then
            Sort_Case_Table (Table);
         end if;

         --  STEP 1 (b):  take care of the whole set of discrete choices

         for J in 1 .. Nb_Choices loop
            Low  := Table (J).Choice_Lo;
            High := Table (J).Choice_Hi;
            Expr := Table (J).Choice_Node;
            Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
         end loop;

         --  STEP 1 (c): generate the remaining loops to cover others choice
         --  We don't need to generate loops over empty gaps, but if there is
         --  a single empty range we must analyze the expression for semantics

         if Present (Others_Expr) or else Others_Box_Present then
            declare
               First : Boolean := True;

            begin
               for J in 0 .. Nb_Choices loop
                  if J = 0 then
                     Low := Aggr_Low;
                  else
                     Low := Add (1, To => Table (J).Choice_Hi);
                  end if;

                  if J = Nb_Choices then
                     High := Aggr_High;
                  else
                     High := Add (-1, To => Table (J + 1).Choice_Lo);
                  end if;

                  --  If this is an expansion within an init proc, make
                  --  sure that discriminant references are replaced by
                  --  the corresponding discriminal.

                  if Inside_Init_Proc then
                     if Is_Entity_Name (Low)
                       and then Ekind (Entity (Low)) = E_Discriminant
                     then
                        Set_Entity (Low, Discriminal (Entity (Low)));
                     end if;

                     if Is_Entity_Name (High)
                       and then Ekind (Entity (High)) = E_Discriminant
                     then
                        Set_Entity (High, Discriminal (Entity (High)));
                     end if;
                  end if;

                  if First
                    or else not Empty_Range (Low, High)
                  then
                     First := False;
                     Append_List
                       (Gen_Loop (Low, High, Others_Expr), To => New_Code);
                  end if;
               end loop;
            end;
         end if;

      --  STEP 2: Process positional components

      else
         --  STEP 2 (a): Generate the assignments for each positional element
         --  Note that here we have to use Aggr_L rather than Aggr_Low because
         --  Aggr_L is analyzed and Add wants an analyzed expression.

         Expr        := First (Expressions (N));
         Nb_Elements := -1;
         while Present (Expr) loop
            Nb_Elements := Nb_Elements + 1;
            Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
                         To => New_Code);
            Next (Expr);
         end loop;

         --  STEP 2 (b): Generate final loop if an others choice is present
         --  Here Nb_Elements gives the offset of the last positional element.

         if Present (Component_Associations (N)) then
            Assoc := Last (Component_Associations (N));

            --  Ada 2005 (AI-287)

            if Box_Present (Assoc) then
               Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
                                       Aggr_High,
                                       Empty),
                            To => New_Code);
            else
               Expr  := Expression (Assoc);

               Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
                                       Aggr_High,
                                       Expr), --  AI-287
                            To => New_Code);
            end if;
         end if;
      end if;

      return New_Code;
   end Build_Array_Aggr_Code;

   ----------------------------
   -- Build_Record_Aggr_Code --
   ----------------------------

   function Build_Record_Aggr_Code
     (N   : Node_Id;
      Typ : Entity_Id;
      Lhs : Node_Id) return List_Id
   is
      Loc     : constant Source_Ptr := Sloc (N);
      L       : constant List_Id    := New_List;
      N_Typ   : constant Entity_Id  := Etype (N);

      Comp      : Node_Id;
      Instr     : Node_Id;
      Ref       : Node_Id;
      Target    : Entity_Id;
      Comp_Type : Entity_Id;
      Selector  : Entity_Id;
      Comp_Expr : Node_Id;
      Expr_Q    : Node_Id;

      --  If this is an internal aggregate, the External_Final_List is an
      --  expression for the controller record of the enclosing type.

      --  If the current aggregate has several controlled components, this
      --  expression will appear in several calls to attach to the finali-
      --  zation list, and it must not be shared.

      Ancestor_Is_Expression   : Boolean := False;
      Ancestor_Is_Subtype_Mark : Boolean := False;

      Init_Typ : Entity_Id := Empty;

      Finalization_Done : Boolean := False;
      --  True if Generate_Finalization_Actions has already been called; calls
      --  after the first do nothing.

      function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
      --  Returns the value that the given discriminant of an ancestor type
      --  should receive (in the absence of a conflict with the value provided
      --  by an ancestor part of an extension aggregate).

      procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
      --  Check that each of the discriminant values defined by the ancestor
      --  part of an extension aggregate match the corresponding values
      --  provided by either an association of the aggregate or by the
      --  constraint imposed by a parent type (RM95-4.3.2(8)).

      function Compatible_Int_Bounds
        (Agg_Bounds : Node_Id;
         Typ_Bounds : Node_Id) return Boolean;
      --  Return true if Agg_Bounds are equal or within Typ_Bounds. It is
      --  assumed that both bounds are integer ranges.

      procedure Generate_Finalization_Actions;
      --  Deal with the various controlled type data structure initializations
      --  (but only if it hasn't been done already).

      function Get_Constraint_Association (T : Entity_Id) return Node_Id;
      --  Returns the first discriminant association in the constraint
      --  associated with T, if any, otherwise returns Empty.

      procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
      --  If Typ is derived, and constrains discriminants of the parent type,
      --  these discriminants are not components of the aggregate, and must be
      --  initialized. The assignments are appended to List.

      function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
      --  Check whether Bounds is a range node and its lower and higher bounds
      --  are integers literals.

      ---------------------------------
      -- Ancestor_Discriminant_Value --
      ---------------------------------

      function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
         Assoc        : Node_Id;
         Assoc_Elmt   : Elmt_Id;
         Aggr_Comp    : Entity_Id;
         Corresp_Disc : Entity_Id;
         Current_Typ  : Entity_Id := Base_Type (Typ);
         Parent_Typ   : Entity_Id;
         Parent_Disc  : Entity_Id;
         Save_Assoc   : Node_Id := Empty;

      begin
         --  First check any discriminant associations to see if any of them
         --  provide a value for the discriminant.

         if Present (Discriminant_Specifications (Parent (Current_Typ))) then
            Assoc := First (Component_Associations (N));
            while Present (Assoc) loop
               Aggr_Comp := Entity (First (Choices (Assoc)));

               if Ekind (Aggr_Comp) = E_Discriminant then
                  Save_Assoc := Expression (Assoc);

                  Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
                  while Present (Corresp_Disc) loop

                     --  If found a corresponding discriminant then return the
                     --  value given in the aggregate. (Note: this is not
                     --  correct in the presence of side effects. ???)

                     if Disc = Corresp_Disc then
                        return Duplicate_Subexpr (Expression (Assoc));
                     end if;

                     Corresp_Disc :=
                       Corresponding_Discriminant (Corresp_Disc);
                  end loop;
               end if;

               Next (Assoc);
            end loop;
         end if;

         --  No match found in aggregate, so chain up parent types to find
         --  a constraint that defines the value of the discriminant.

         Parent_Typ := Etype (Current_Typ);
         while Current_Typ /= Parent_Typ loop
            if Has_Discriminants (Parent_Typ)
              and then not Has_Unknown_Discriminants (Parent_Typ)
            then
               Parent_Disc := First_Discriminant (Parent_Typ);

               --  We either get the association from the subtype indication
               --  of the type definition itself, or from the discriminant
               --  constraint associated with the type entity (which is
               --  preferable, but it's not always present ???)

               if Is_Empty_Elmt_List (
                 Discriminant_Constraint (Current_Typ))
               then
                  Assoc := Get_Constraint_Association (Current_Typ);
                  Assoc_Elmt := No_Elmt;
               else
                  Assoc_Elmt :=
                    First_Elmt (Discriminant_Constraint (Current_Typ));
                  Assoc := Node (Assoc_Elmt);
               end if;

               --  Traverse the discriminants of the parent type looking
               --  for one that corresponds.

               while Present (Parent_Disc) and then Present (Assoc) loop
                  Corresp_Disc := Parent_Disc;
                  while Present (Corresp_Disc)
                    and then Disc /= Corresp_Disc
                  loop
                     Corresp_Disc :=
                       Corresponding_Discriminant (Corresp_Disc);
                  end loop;

                  if Disc = Corresp_Disc then
                     if Nkind (Assoc) = N_Discriminant_Association then
                        Assoc := Expression (Assoc);
                     end if;

                     --  If the located association directly denotes a
                     --  discriminant, then use the value of a saved
                     --  association of the aggregate. This is a kludge to
                     --  handle certain cases involving multiple discriminants
                     --  mapped to a single discriminant of a descendant. It's
                     --  not clear how to locate the appropriate discriminant
                     --  value for such cases. ???

                     if Is_Entity_Name (Assoc)
                       and then Ekind (Entity (Assoc)) = E_Discriminant
                     then
                        Assoc := Save_Assoc;
                     end if;

                     return Duplicate_Subexpr (Assoc);
                  end if;

                  Next_Discriminant (Parent_Disc);

                  if No (Assoc_Elmt) then
                     Next (Assoc);
                  else
                     Next_Elmt (Assoc_Elmt);
                     if Present (Assoc_Elmt) then
                        Assoc := Node (Assoc_Elmt);
                     else
                        Assoc := Empty;
                     end if;
                  end if;
               end loop;
            end if;

            Current_Typ := Parent_Typ;
            Parent_Typ := Etype (Current_Typ);
         end loop;

         --  In some cases there's no ancestor value to locate (such as
         --  when an ancestor part given by an expression defines the
         --  discriminant value).

         return Empty;
      end Ancestor_Discriminant_Value;

      ----------------------------------
      -- Check_Ancestor_Discriminants --
      ----------------------------------

      procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
         Discr      : Entity_Id;
         Disc_Value : Node_Id;
         Cond       : Node_Id;

      begin
         Discr := First_Discriminant (Base_Type (Anc_Typ));
         while Present (Discr) loop
            Disc_Value := Ancestor_Discriminant_Value (Discr);

            if Present (Disc_Value) then
               Cond := Make_Op_Ne (Loc,
                 Left_Opnd =>
                   Make_Selected_Component (Loc,
                     Prefix        => New_Copy_Tree (Target),
                     Selector_Name => New_Occurrence_Of (Discr, Loc)),
                 Right_Opnd => Disc_Value);

               Append_To (L,
                 Make_Raise_Constraint_Error (Loc,
                   Condition => Cond,
                   Reason    => CE_Discriminant_Check_Failed));
            end if;

            Next_Discriminant (Discr);
         end loop;
      end Check_Ancestor_Discriminants;

      ---------------------------
      -- Compatible_Int_Bounds --
      ---------------------------

      function Compatible_Int_Bounds
        (Agg_Bounds : Node_Id;
         Typ_Bounds : Node_Id) return Boolean
      is
         Agg_Lo : constant Uint := Intval (Low_Bound  (Agg_Bounds));
         Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
         Typ_Lo : constant Uint := Intval (Low_Bound  (Typ_Bounds));
         Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
      begin
         return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
      end Compatible_Int_Bounds;

      --------------------------------
      -- Get_Constraint_Association --
      --------------------------------

      function Get_Constraint_Association (T : Entity_Id) return Node_Id is
         Indic : Node_Id;
         Typ   : Entity_Id;

      begin
         Typ := T;

         --  Handle private types in instances

         if In_Instance
           and then Is_Private_Type (Typ)
           and then Present (Full_View (Typ))
         then
            Typ := Full_View (Typ);
         end if;

         Indic := Subtype_Indication (Type_Definition (Parent (Typ)));

         --  ??? Also need to cover case of a type mark denoting a subtype
         --  with constraint.

         if Nkind (Indic) = N_Subtype_Indication
           and then Present (Constraint (Indic))
         then
            return First (Constraints (Constraint (Indic)));
         end if;

         return Empty;
      end Get_Constraint_Association;

      -------------------------------
      -- Init_Hidden_Discriminants --
      -------------------------------

      procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
         Btype       : Entity_Id;
         Parent_Type : Entity_Id;
         Disc        : Entity_Id;
         Discr_Val   : Elmt_Id;

      begin
         Btype := Base_Type (Typ);
         while Is_Derived_Type (Btype)
           and then Present (Stored_Constraint (Btype))
         loop
            Parent_Type := Etype (Btype);

            Disc := First_Discriminant (Parent_Type);
            Discr_Val := First_Elmt (Stored_Constraint (Base_Type (Typ)));
            while Present (Discr_Val) loop

               --  Only those discriminants of the parent that are not
               --  renamed by discriminants of the derived type need to
               --  be added explicitly.

               if not Is_Entity_Name (Node (Discr_Val))
                 or else Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
               then
                  Comp_Expr :=
                    Make_Selected_Component (Loc,
                      Prefix        => New_Copy_Tree (Target),
                      Selector_Name => New_Occurrence_Of (Disc, Loc));

                  Instr :=
                    Make_OK_Assignment_Statement (Loc,
                      Name       => Comp_Expr,
                      Expression => New_Copy_Tree (Node (Discr_Val)));

                  Set_No_Ctrl_Actions (Instr);
                  Append_To (List, Instr);
               end if;

               Next_Discriminant (Disc);
               Next_Elmt (Discr_Val);
            end loop;

            Btype := Base_Type (Parent_Type);
         end loop;
      end Init_Hidden_Discriminants;

      -------------------------
      -- Is_Int_Range_Bounds --
      -------------------------

      function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
      begin
         return Nkind (Bounds) = N_Range
           and then Nkind (Low_Bound  (Bounds)) = N_Integer_Literal
           and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
      end Is_Int_Range_Bounds;

      -----------------------------------
      -- Generate_Finalization_Actions --
      -----------------------------------

      procedure Generate_Finalization_Actions is
      begin
         --  Do the work only the first time this is called

         if Finalization_Done then
            return;
         end if;

         Finalization_Done := True;

         --  Determine the external finalization list. It is either the
         --  finalization list of the outer-scope or the one coming from
         --  an outer aggregate. When the target is not a temporary, the
         --  proper scope is the scope of the target rather than the
         --  potentially transient current scope.

         if Is_Controlled (Typ)
           and then Ancestor_Is_Subtype_Mark
         then
            Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
            Set_Assignment_OK (Ref);

            Append_To (L,
              Make_Procedure_Call_Statement (Loc,
                Name =>
                  New_Reference_To
                    (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
                Parameter_Associations => New_List (New_Copy_Tree (Ref))));
         end if;
      end Generate_Finalization_Actions;

      function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
      --  If default expression of a component mentions a discriminant of the
      --  type, it must be rewritten as the discriminant of the target object.

      function Replace_Type (Expr : Node_Id) return Traverse_Result;
      --  If the aggregate contains a self-reference, traverse each expression
      --  to replace a possible self-reference with a reference to the proper
      --  component of the target of the assignment.

      --------------------------
      -- Rewrite_Discriminant --
      --------------------------

      function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
      begin
         if Is_Entity_Name (Expr)
           and then Present (Entity (Expr))
           and then Ekind (Entity (Expr)) = E_In_Parameter
           and then Present (Discriminal_Link (Entity (Expr)))
           and then Scope (Discriminal_Link (Entity (Expr)))
                      = Base_Type (Etype (N))
         then
            Rewrite (Expr,
              Make_Selected_Component (Loc,
                Prefix        => New_Copy_Tree (Lhs),
                Selector_Name => Make_Identifier (Loc, Chars (Expr))));
         end if;
         return OK;
      end Rewrite_Discriminant;

      ------------------
      -- Replace_Type --
      ------------------

      function Replace_Type (Expr : Node_Id) return Traverse_Result is
      begin
         --  Note regarding the Root_Type test below: Aggregate components for
         --  self-referential types include attribute references to the current
         --  instance, of the form: Typ'access, etc.. These references are
         --  rewritten as references to the target of the aggregate: the
         --  left-hand side of an assignment, the entity in a declaration,
         --  or a temporary. Without this test, we would improperly extended
         --  this rewriting to attribute references whose prefix was not the
         --  type of the aggregate.

         if Nkind (Expr) = N_Attribute_Reference
           and then Is_Entity_Name (Prefix (Expr))
           and then Is_Type (Entity (Prefix (Expr)))
           and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
         then
            if Is_Entity_Name (Lhs) then
               Rewrite (Prefix (Expr),
                 New_Occurrence_Of (Entity (Lhs), Loc));

            elsif Nkind (Lhs) = N_Selected_Component then
               Rewrite (Expr,
                 Make_Attribute_Reference (Loc,
                   Attribute_Name => Name_Unrestricted_Access,
                   Prefix         => New_Copy_Tree (Lhs)));
               Set_Analyzed (Parent (Expr), False);

            else
               Rewrite (Expr,
                 Make_Attribute_Reference (Loc,
                   Attribute_Name => Name_Unrestricted_Access,
                   Prefix         => New_Copy_Tree (Lhs)));
               Set_Analyzed (Parent (Expr), False);
            end if;
         end if;

         return OK;
      end Replace_Type;

      procedure Replace_Self_Reference is
        new Traverse_Proc (Replace_Type);

      procedure Replace_Discriminants is
        new Traverse_Proc (Rewrite_Discriminant);

   --  Start of processing for Build_Record_Aggr_Code

   begin
      if Has_Self_Reference (N) then
         Replace_Self_Reference (N);
      end if;

      --  If the target of the aggregate is class-wide, we must convert it
      --  to the actual type of the aggregate, so that the proper components
      --  are visible. We know already that the types are compatible.

      if Present (Etype (Lhs))
        and then Is_Class_Wide_Type (Etype (Lhs))
      then
         Target := Unchecked_Convert_To (Typ, Lhs);
      else
         Target := Lhs;
      end if;

      --  Deal with the ancestor part of extension aggregates or with the
      --  discriminants of the root type.

      if Nkind (N) = N_Extension_Aggregate then
         declare
            Ancestor : constant Node_Id := Ancestor_Part (N);
            Assign   : List_Id;

         begin
            --  If the ancestor part is a subtype mark "T", we generate

            --     init-proc (T (tmp));  if T is constrained and
            --     init-proc (S (tmp));  where S applies an appropriate
            --                           constraint if T is unconstrained

            if Is_Entity_Name (Ancestor)
              and then Is_Type (Entity (Ancestor))
            then
               Ancestor_Is_Subtype_Mark := True;

               if Is_Constrained (Entity (Ancestor)) then
                  Init_Typ := Entity (Ancestor);

               --  For an ancestor part given by an unconstrained type mark,
               --  create a subtype constrained by appropriate corresponding
               --  discriminant values coming from either associations of the
               --  aggregate or a constraint on a parent type. The subtype will
               --  be used to generate the correct default value for the
               --  ancestor part.

               elsif Has_Discriminants (Entity (Ancestor)) then
                  declare
                     Anc_Typ    : constant Entity_Id := Entity (Ancestor);
                     Anc_Constr : constant List_Id   := New_List;
                     Discrim    : Entity_Id;
                     Disc_Value : Node_Id;
                     New_Indic  : Node_Id;
                     Subt_Decl  : Node_Id;

                  begin
                     Discrim := First_Discriminant (Anc_Typ);
                     while Present (Discrim) loop
                        Disc_Value := Ancestor_Discriminant_Value (Discrim);
                        Append_To (Anc_Constr, Disc_Value);
                        Next_Discriminant (Discrim);
                     end loop;

                     New_Indic :=
                       Make_Subtype_Indication (Loc,
                         Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
                         Constraint   =>
                           Make_Index_Or_Discriminant_Constraint (Loc,
                             Constraints => Anc_Constr));

                     Init_Typ := Create_Itype (Ekind (Anc_Typ), N);

                     Subt_Decl :=
                       Make_Subtype_Declaration (Loc,
                         Defining_Identifier => Init_Typ,
                         Subtype_Indication  => New_Indic);

                     --  Itypes must be analyzed with checks off Declaration
                     --  must have a parent for proper handling of subsidiary
                     --  actions.

                     Set_Parent (Subt_Decl, N);
                     Analyze (Subt_Decl, Suppress => All_Checks);
                  end;
               end if;

               Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
               Set_Assignment_OK (Ref);

               if not Is_Interface (Init_Typ) then
                  Append_List_To (L,
                    Build_Initialization_Call (Loc,
                      Id_Ref            => Ref,
                      Typ               => Init_Typ,
                      In_Init_Proc      => Within_Init_Proc,
                      With_Default_Init => Has_Default_Init_Comps (N)
                                             or else
                                           Has_Task (Base_Type (Init_Typ))));

                  if Is_Constrained (Entity (Ancestor))
                    and then Has_Discriminants (Entity (Ancestor))
                  then
                     Check_Ancestor_Discriminants (Entity (Ancestor));
                  end if;
               end if;

            --  Handle calls to C++ constructors

            elsif Is_CPP_Constructor_Call (Ancestor) then
               Init_Typ := Etype (Ancestor);
               Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
               Set_Assignment_OK (Ref);

               Append_List_To (L,
                 Build_Initialization_Call (Loc,
                   Id_Ref            => Ref,
                   Typ               => Init_Typ,
                   In_Init_Proc      => Within_Init_Proc,
                   With_Default_Init => Has_Default_Init_Comps (N),
                   Constructor_Ref   => Ancestor));

            --  Ada 2005 (AI-287): If the ancestor part is an aggregate of
            --  limited type, a recursive call expands the ancestor. Note that
            --  in the limited case, the ancestor part must be either a
            --  function call (possibly qualified, or wrapped in an unchecked
            --  conversion) or aggregate (definitely qualified).
            --  The ancestor part can also be a function call (that may be
            --  transformed into an explicit dereference) or a qualification
            --  of one such.

            elsif Is_Limited_Type (Etype (Ancestor))
              and then Nkind_In (Unqualify (Ancestor), N_Aggregate,
                                                    N_Extension_Aggregate)
            then
               Ancestor_Is_Expression := True;

               --  Set up  finalization data for enclosing record, because
               --  controlled subcomponents of the ancestor part will be
               --  attached to it.

               Generate_Finalization_Actions;

               Append_List_To (L,
                  Build_Record_Aggr_Code
                    (N   => Unqualify (Ancestor),
                     Typ => Etype (Unqualify (Ancestor)),
                     Lhs => Target));

            --  If the ancestor part is an expression "E", we generate

            --     T (tmp) := E;

            --  In Ada 2005, this includes the case of a (possibly qualified)
            --  limited function call. The assignment will turn into a
            --  build-in-place function call (for further details, see
            --  Make_Build_In_Place_Call_In_Assignment).

            else
               Ancestor_Is_Expression := True;
               Init_Typ := Etype (Ancestor);

               --  If the ancestor part is an aggregate, force its full
               --  expansion, which was delayed.

               if Nkind_In (Unqualify (Ancestor), N_Aggregate,
                                               N_Extension_Aggregate)
               then
                  Set_Analyzed (Ancestor, False);
                  Set_Analyzed (Expression (Ancestor), False);
               end if;

               Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
               Set_Assignment_OK (Ref);

               --  Make the assignment without usual controlled actions since
               --  we only want the post adjust but not the pre finalize here
               --  Add manual adjust when necessary.

               Assign := New_List (
                 Make_OK_Assignment_Statement (Loc,
                   Name       => Ref,
                   Expression => Ancestor));
               Set_No_Ctrl_Actions (First (Assign));

               --  Assign the tag now to make sure that the dispatching call in
               --  the subsequent deep_adjust works properly (unless VM_Target,
               --  where tags are implicit).

               if Tagged_Type_Expansion then
                  Instr :=
                    Make_OK_Assignment_Statement (Loc,
                      Name =>
                        Make_Selected_Component (Loc,
                          Prefix => New_Copy_Tree (Target),
                          Selector_Name =>
                            New_Reference_To
                              (First_Tag_Component (Base_Type (Typ)), Loc)),

                      Expression =>
                        Unchecked_Convert_To (RTE (RE_Tag),
                          New_Reference_To
                            (Node (First_Elmt
                               (Access_Disp_Table (Base_Type (Typ)))),
                             Loc)));

                  Set_Assignment_OK (Name (Instr));
                  Append_To (Assign, Instr);

                  --  Ada 2005 (AI-251): If tagged type has progenitors we must
                  --  also initialize tags of the secondary dispatch tables.

                  if Has_Interfaces (Base_Type (Typ)) then
                     Init_Secondary_Tags
                       (Typ        => Base_Type (Typ),
                        Target     => Target,
                        Stmts_List => Assign);
                  end if;
               end if;

               --  Call Adjust manually

               if Needs_Finalization (Etype (Ancestor))
                 and then not Is_Limited_Type (Etype (Ancestor))
               then
                  Append_To (Assign,
                    Make_Adjust_Call (
                      Obj_Ref => New_Copy_Tree (Ref),
                      Typ     => Etype (Ancestor)));
               end if;

               Append_To (L,
                 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));

               if Has_Discriminants (Init_Typ) then
                  Check_Ancestor_Discriminants (Init_Typ);
               end if;
            end if;
         end;

         --  Generate assignments of hidden assignments. If the base type is an
         --  unchecked union, the discriminants are unknown to the back-end and
         --  absent from a value of the type, so assignments for them are not
         --  emitted.

         if Has_Discriminants (Typ)
           and then not Is_Unchecked_Union (Base_Type (Typ))
         then
            Init_Hidden_Discriminants (Typ, L);
         end if;

      --  Normal case (not an extension aggregate)

      else
         --  Generate the discriminant expressions, component by component.
         --  If the base type is an unchecked union, the discriminants are
         --  unknown to the back-end and absent from a value of the type, so
         --  assignments for them are not emitted.

         if Has_Discriminants (Typ)
           and then not Is_Unchecked_Union (Base_Type (Typ))
         then
            Init_Hidden_Discriminants (Typ, L);

            --  Generate discriminant init values for the visible discriminants

            declare
               Discriminant : Entity_Id;
               Discriminant_Value : Node_Id;

            begin
               Discriminant := First_Stored_Discriminant (Typ);
               while Present (Discriminant) loop
                  Comp_Expr :=
                    Make_Selected_Component (Loc,
                      Prefix        => New_Copy_Tree (Target),
                      Selector_Name => New_Occurrence_Of (Discriminant, Loc));

                  Discriminant_Value :=
                    Get_Discriminant_Value (
                      Discriminant,
                      N_Typ,
                      Discriminant_Constraint (N_Typ));

                  Instr :=
                    Make_OK_Assignment_Statement (Loc,
                      Name       => Comp_Expr,
                      Expression => New_Copy_Tree (Discriminant_Value));

                  Set_No_Ctrl_Actions (Instr);
                  Append_To (L, Instr);

                  Next_Stored_Discriminant (Discriminant);
               end loop;
            end;
         end if;
      end if;

      --  For CPP types we generate an implicit call to the C++ default
      --  constructor to ensure the proper initialization of the _Tag
      --  component.

      if Is_CPP_Class (Root_Type (Typ))
        and then CPP_Num_Prims (Typ) > 0
      then
         Invoke_Constructor : declare
            CPP_Parent : constant Entity_Id :=
                           Enclosing_CPP_Parent (Typ);

            procedure Invoke_IC_Proc (T : Entity_Id);
            --  Recursive routine used to climb to parents. Required because
            --  parents must be initialized before descendants to ensure
            --  propagation of inherited C++ slots.

            --------------------
            -- Invoke_IC_Proc --
            --------------------

            procedure Invoke_IC_Proc (T : Entity_Id) is
            begin
               --  Avoid generating extra calls. Initialization required
               --  only for types defined from the level of derivation of
               --  type of the constructor and the type of the aggregate.

               if T = CPP_Parent then
                  return;
               end if;

               Invoke_IC_Proc (Etype (T));

               --  Generate call to the IC routine

               if Present (CPP_Init_Proc (T)) then
                  Append_To (L,
                    Make_Procedure_Call_Statement (Loc,
                      New_Reference_To (CPP_Init_Proc (T), Loc)));
               end if;
            end Invoke_IC_Proc;

         --  Start of processing for Invoke_Constructor

         begin
            --  Implicit invocation of the C++ constructor

            if Nkind (N) = N_Aggregate then
               Append_To (L,
                 Make_Procedure_Call_Statement (Loc,
                   Name =>
                     New_Reference_To
                       (Base_Init_Proc (CPP_Parent), Loc),
                   Parameter_Associations => New_List (
                     Unchecked_Convert_To (CPP_Parent,
                       New_Copy_Tree (Lhs)))));
            end if;

            Invoke_IC_Proc (Typ);
         end Invoke_Constructor;
      end if;

      --  Generate the assignments, component by component

      --    tmp.comp1 := Expr1_From_Aggr;
      --    tmp.comp2 := Expr2_From_Aggr;
      --    ....

      Comp := First (Component_Associations (N));
      while Present (Comp) loop
         Selector := Entity (First (Choices (Comp)));

         --  C++ constructors

         if Is_CPP_Constructor_Call (Expression (Comp)) then
            Append_List_To (L,
              Build_Initialization_Call (Loc,
                Id_Ref            => Make_Selected_Component (Loc,
                                       Prefix        => New_Copy_Tree (Target),
                                       Selector_Name =>
                                         New_Occurrence_Of (Selector, Loc)),
                Typ               => Etype (Selector),
                Enclos_Type       => Typ,
                With_Default_Init => True,
                Constructor_Ref   => Expression (Comp)));

         --  Ada 2005 (AI-287): For each default-initialized component generate
         --  a call to the corresponding IP subprogram if available.

         elsif Box_Present (Comp)
           and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
         then
            if Ekind (Selector) /= E_Discriminant then
               Generate_Finalization_Actions;
            end if;

            --  Ada 2005 (AI-287): If the component type has tasks then
            --  generate the activation chain and master entities (except
            --  in case of an allocator because in that case these entities
            --  are generated by Build_Task_Allocate_Block_With_Init_Stmts).

            declare
               Ctype            : constant Entity_Id := Etype (Selector);
               Inside_Allocator : Boolean            := False;
               P                : Node_Id            := Parent (N);

            begin
               if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
                  while Present (P) loop
                     if Nkind (P) = N_Allocator then
                        Inside_Allocator := True;
                        exit;
                     end if;

                     P := Parent (P);
                  end loop;

                  if not Inside_Init_Proc and not Inside_Allocator then
                     Build_Activation_Chain_Entity (N);
                  end if;
               end if;
            end;

            Append_List_To (L,
              Build_Initialization_Call (Loc,
                Id_Ref            => Make_Selected_Component (Loc,
                                       Prefix        => New_Copy_Tree (Target),
                                       Selector_Name =>
                                         New_Occurrence_Of (Selector, Loc)),
                Typ               => Etype (Selector),
                Enclos_Type       => Typ,
                With_Default_Init => True));

         --  Prepare for component assignment

         elsif Ekind (Selector) /= E_Discriminant
           or else Nkind (N) = N_Extension_Aggregate
         then
            --  All the discriminants have now been assigned

            --  This is now a good moment to initialize and attach all the
            --  controllers. Their position may depend on the discriminants.

            if Ekind (Selector) /= E_Discriminant then
               Generate_Finalization_Actions;
            end if;

            Comp_Type := Underlying_Type (Etype (Selector));
            Comp_Expr :=
              Make_Selected_Component (Loc,
                Prefix        => New_Copy_Tree (Target),
                Selector_Name => New_Occurrence_Of (Selector, Loc));

            if Nkind (Expression (Comp)) = N_Qualified_Expression then
               Expr_Q := Expression (Expression (Comp));
            else
               Expr_Q := Expression (Comp);
            end if;

            --  Now either create the assignment or generate the code for the
            --  inner aggregate top-down.

            if Is_Delayed_Aggregate (Expr_Q) then

               --  We have the following case of aggregate nesting inside
               --  an object declaration:

               --    type Arr_Typ is array (Integer range <>) of ...;

               --    type Rec_Typ (...) is record
               --       Obj_Arr_Typ : Arr_Typ (A .. B);
               --    end record;

               --    Obj_Rec_Typ : Rec_Typ := (...,
               --      Obj_Arr_Typ => (X => (...), Y => (...)));

               --  The length of the ranges of the aggregate and Obj_Add_Typ
               --  are equal (B - A = Y - X), but they do not coincide (X /=
               --  A and B /= Y). This case requires array sliding which is
               --  performed in the following manner:

               --    subtype Arr_Sub is Arr_Typ (X .. Y);
               --    Temp : Arr_Sub;
               --    Temp (X) := (...);
               --    ...
               --    Temp (Y) := (...);
               --    Obj_Rec_Typ.Obj_Arr_Typ := Temp;

               if Ekind (Comp_Type) = E_Array_Subtype
                 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
                 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
                 and then not
                   Compatible_Int_Bounds
                     (Agg_Bounds => Aggregate_Bounds (Expr_Q),
                      Typ_Bounds => First_Index (Comp_Type))
               then
                  --  Create the array subtype with bounds equal to those of
                  --  the corresponding aggregate.

                  declare
                     SubE : constant Entity_Id := Make_Temporary (Loc, 'T');

                     SubD : constant Node_Id :=
                              Make_Subtype_Declaration (Loc,
                                Defining_Identifier => SubE,
                                Subtype_Indication  =>
                                  Make_Subtype_Indication (Loc,
                                    Subtype_Mark =>
                                      New_Reference_To
                                        (Etype (Comp_Type), Loc),
                                    Constraint =>
                                      Make_Index_Or_Discriminant_Constraint
                                        (Loc,
                                         Constraints => New_List (
                                          New_Copy_Tree
                                            (Aggregate_Bounds (Expr_Q))))));

                     --  Create a temporary array of the above subtype which
                     --  will be used to capture the aggregate assignments.

                     TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);

                     TmpD : constant Node_Id :=
                              Make_Object_Declaration (Loc,
                                Defining_Identifier => TmpE,
                                Object_Definition   =>
                                  New_Reference_To (SubE, Loc));

                  begin
                     Set_No_Initialization (TmpD);
                     Append_To (L, SubD);
                     Append_To (L, TmpD);

                     --  Expand aggregate into assignments to the temp array

                     Append_List_To (L,
                       Late_Expansion (Expr_Q, Comp_Type,
                         New_Reference_To (TmpE, Loc)));

                     --  Slide

                     Append_To (L,
                       Make_Assignment_Statement (Loc,
                         Name       => New_Copy_Tree (Comp_Expr),
                         Expression => New_Reference_To (TmpE, Loc)));
                  end;

               --  Normal case (sliding not required)

               else
                  Append_List_To (L,
                    Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
               end if;

            --  Expr_Q is not delayed aggregate

            else
               if Has_Discriminants (Typ) then
                  Replace_Discriminants (Expr_Q);
               end if;

               Instr :=
                 Make_OK_Assignment_Statement (Loc,
                   Name       => Comp_Expr,
                   Expression => Expr_Q);

               Set_No_Ctrl_Actions (Instr);
               Append_To (L, Instr);

               --  Adjust the tag if tagged (because of possible view
               --  conversions), unless compiling for a VM where tags are
               --  implicit.

               --    tmp.comp._tag := comp_typ'tag;

               if Is_Tagged_Type (Comp_Type)
                 and then Tagged_Type_Expansion
               then
                  Instr :=
                    Make_OK_Assignment_Statement (Loc,
                      Name =>
                        Make_Selected_Component (Loc,
                          Prefix =>  New_Copy_Tree (Comp_Expr),
                          Selector_Name =>
                            New_Reference_To
                              (First_Tag_Component (Comp_Type), Loc)),

                      Expression =>
                        Unchecked_Convert_To (RTE (RE_Tag),
                          New_Reference_To
                            (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
                             Loc)));

                  Append_To (L, Instr);
               end if;

               --  Generate:
               --    Adjust (tmp.comp);

               if Needs_Finalization (Comp_Type)
                 and then not Is_Limited_Type (Comp_Type)
               then
                  Append_To (L,
                    Make_Adjust_Call (
                      Obj_Ref => New_Copy_Tree (Comp_Expr),
                      Typ     => Comp_Type));
               end if;
            end if;

         --  ???

         elsif Ekind (Selector) = E_Discriminant
           and then Nkind (N) /= N_Extension_Aggregate
           and then Nkind (Parent (N)) = N_Component_Association
           and then Is_Constrained (Typ)
         then
            --  We must check that the discriminant value imposed by the
            --  context is the same as the value given in the subaggregate,
            --  because after the expansion into assignments there is no
            --  record on which to perform a regular discriminant check.

            declare
               D_Val : Elmt_Id;
               Disc  : Entity_Id;

            begin
               D_Val := First_Elmt (Discriminant_Constraint (Typ));
               Disc  := First_Discriminant (Typ);
               while Chars (Disc) /= Chars (Selector) loop
                  Next_Discriminant (Disc);
                  Next_Elmt (D_Val);
               end loop;

               pragma Assert (Present (D_Val));

               --  This check cannot performed for components that are
               --  constrained by a current instance, because this is not a
               --  value that can be compared with the actual constraint.

               if Nkind (Node (D_Val)) /= N_Attribute_Reference
                 or else not Is_Entity_Name (Prefix (Node (D_Val)))
                 or else not Is_Type (Entity (Prefix (Node (D_Val))))
               then
                  Append_To (L,
                  Make_Raise_Constraint_Error (Loc,
                    Condition =>
                      Make_Op_Ne (Loc,
                        Left_Opnd => New_Copy_Tree (Node (D_Val)),
                        Right_Opnd => Expression (Comp)),
                      Reason => CE_Discriminant_Check_Failed));

               else
                  --  Find self-reference in previous discriminant assignment,
                  --  and replace with proper expression.

                  declare
                     Ass : Node_Id;

                  begin
                     Ass := First (L);
                     while Present (Ass) loop
                        if Nkind (Ass) = N_Assignment_Statement
                          and then Nkind (Name (Ass)) = N_Selected_Component
                          and then Chars (Selector_Name (Name (Ass))) =
                             Chars (Disc)
                        then
                           Set_Expression
                             (Ass, New_Copy_Tree (Expression (Comp)));
                           exit;
                        end if;
                        Next (Ass);
                     end loop;
                  end;
               end if;
            end;
         end if;

         Next (Comp);
      end loop;

      --  If the type is tagged, the tag needs to be initialized (unless
      --  compiling for the Java VM where tags are implicit). It is done
      --  late in the initialization process because in some cases, we call
      --  the init proc of an ancestor which will not leave out the right tag

      if Ancestor_Is_Expression then
         null;

      --  For CPP types we generated a call to the C++ default constructor
      --  before the components have been initialized to ensure the proper
      --  initialization of the _Tag component (see above).

      elsif Is_CPP_Class (Typ) then
         null;

      elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
         Instr :=
           Make_OK_Assignment_Statement (Loc,
             Name =>
               Make_Selected_Component (Loc,
                 Prefix => New_Copy_Tree (Target),
                 Selector_Name =>
                   New_Reference_To
                     (First_Tag_Component (Base_Type (Typ)), Loc)),

             Expression =>
               Unchecked_Convert_To (RTE (RE_Tag),
                 New_Reference_To
                   (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
                    Loc)));

         Append_To (L, Instr);

         --  Ada 2005 (AI-251): If the tagged type has been derived from
         --  abstract interfaces we must also initialize the tags of the
         --  secondary dispatch tables.

         if Has_Interfaces (Base_Type (Typ)) then
            Init_Secondary_Tags
              (Typ        => Base_Type (Typ),
               Target     => Target,
               Stmts_List => L);
         end if;
      end if;

      --  If the controllers have not been initialized yet (by lack of non-
      --  discriminant components), let's do it now.

      Generate_Finalization_Actions;

      return L;
   end Build_Record_Aggr_Code;

   -------------------------------
   -- Convert_Aggr_In_Allocator --
   -------------------------------

   procedure Convert_Aggr_In_Allocator
     (Alloc :  Node_Id;
      Decl  :  Node_Id;
      Aggr  :  Node_Id)
   is
      Loc  : constant Source_Ptr := Sloc (Aggr);
      Typ  : constant Entity_Id  := Etype (Aggr);
      Temp : constant Entity_Id  := Defining_Identifier (Decl);

      Occ  : constant Node_Id :=
               Unchecked_Convert_To (Typ,
                 Make_Explicit_Dereference (Loc,
                   New_Reference_To (Temp, Loc)));

   begin
      if Is_Array_Type (Typ) then
         Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);

      elsif Has_Default_Init_Comps (Aggr) then
         declare
            L          : constant List_Id := New_List;
            Init_Stmts : List_Id;

         begin
            Init_Stmts := Late_Expansion (Aggr, Typ, Occ);

            if Has_Task (Typ) then
               Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
               Insert_Actions (Alloc, L);
            else
               Insert_Actions (Alloc, Init_Stmts);
            end if;
         end;

      else
         Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
      end if;
   end Convert_Aggr_In_Allocator;

   --------------------------------
   -- Convert_Aggr_In_Assignment --
   --------------------------------

   procedure Convert_Aggr_In_Assignment (N : Node_Id) is
      Aggr : Node_Id            := Expression (N);
      Typ  : constant Entity_Id := Etype (Aggr);
      Occ  : constant Node_Id   := New_Copy_Tree (Name (N));

   begin
      if Nkind (Aggr) = N_Qualified_Expression then
         Aggr := Expression (Aggr);
      end if;

      Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
   end Convert_Aggr_In_Assignment;

   ---------------------------------
   -- Convert_Aggr_In_Object_Decl --
   ---------------------------------

   procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
      Obj  : constant Entity_Id  := Defining_Identifier (N);
      Aggr : Node_Id             := Expression (N);
      Loc  : constant Source_Ptr := Sloc (Aggr);
      Typ  : constant Entity_Id  := Etype (Aggr);
      Occ  : constant Node_Id    := New_Occurrence_Of (Obj, Loc);

      function Discriminants_Ok return Boolean;
      --  If the object type is constrained, the discriminants in the
      --  aggregate must be checked against the discriminants of the subtype.
      --  This cannot be done using Apply_Discriminant_Checks because after
      --  expansion there is no aggregate left to check.

      ----------------------
      -- Discriminants_Ok --
      ----------------------

      function Discriminants_Ok return Boolean is
         Cond  : Node_Id := Empty;
         Check : Node_Id;
         D     : Entity_Id;
         Disc1 : Elmt_Id;
         Disc2 : Elmt_Id;
         Val1  : Node_Id;
         Val2  : Node_Id;

      begin
         D := First_Discriminant (Typ);
         Disc1 := First_Elmt (Discriminant_Constraint (Typ));
         Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
         while Present (Disc1) and then Present (Disc2) loop
            Val1 := Node (Disc1);
            Val2 := Node (Disc2);

            if not Is_OK_Static_Expression (Val1)
              or else not Is_OK_Static_Expression (Val2)
            then
               Check := Make_Op_Ne (Loc,
                 Left_Opnd  => Duplicate_Subexpr (Val1),
                 Right_Opnd => Duplicate_Subexpr (Val2));

               if No (Cond) then
                  Cond := Check;

               else
                  Cond := Make_Or_Else (Loc,
                    Left_Opnd => Cond,
                    Right_Opnd => Check);
               end if;

            elsif Expr_Value (Val1) /= Expr_Value (Val2) then
               Apply_Compile_Time_Constraint_Error (Aggr,
                 Msg    => "incorrect value for discriminant&?",
                 Reason => CE_Discriminant_Check_Failed,
                 Ent    => D);
               return False;
            end if;

            Next_Discriminant (D);
            Next_Elmt (Disc1);
            Next_Elmt (Disc2);
         end loop;

         --  If any discriminant constraint is non-static, emit a check

         if Present (Cond) then
            Insert_Action (N,
              Make_Raise_Constraint_Error (Loc,
                Condition => Cond,
                Reason => CE_Discriminant_Check_Failed));
         end if;

         return True;
      end Discriminants_Ok;

   --  Start of processing for Convert_Aggr_In_Object_Decl

   begin
      Set_Assignment_OK (Occ);

      if Nkind (Aggr) = N_Qualified_Expression then
         Aggr := Expression (Aggr);
      end if;

      if Has_Discriminants (Typ)
        and then Typ /= Etype (Obj)
        and then Is_Constrained (Etype (Obj))
        and then not Discriminants_Ok
      then
         return;
      end if;

      --  If the context is an extended return statement, it has its own
      --  finalization machinery (i.e. works like a transient scope) and
      --  we do not want to create an additional one, because objects on
      --  the finalization list of the return must be moved to the caller's
      --  finalization list to complete the return.

      --  However, if the aggregate is limited, it is built in place, and the
      --  controlled components are not assigned to intermediate temporaries
      --  so there is no need for a transient scope in this case either.

      if Requires_Transient_Scope (Typ)
        and then Ekind (Current_Scope) /= E_Return_Statement
        and then not Is_Limited_Type (Typ)
      then
         Establish_Transient_Scope
           (Aggr,
            Sec_Stack =>
              Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
      end if;

      Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
      Set_No_Initialization (N);
      Initialize_Discriminants (N, Typ);
   end Convert_Aggr_In_Object_Decl;

   -------------------------------------
   -- Convert_Array_Aggr_In_Allocator --
   -------------------------------------

   procedure Convert_Array_Aggr_In_Allocator
     (Decl   : Node_Id;
      Aggr   : Node_Id;
      Target : Node_Id)
   is
      Aggr_Code : List_Id;
      Typ       : constant Entity_Id := Etype (Aggr);
      Ctyp      : constant Entity_Id := Component_Type (Typ);

   begin
      --  The target is an explicit dereference of the allocated object.
      --  Generate component assignments to it, as for an aggregate that
      --  appears on the right-hand side of an assignment statement.

      Aggr_Code :=
        Build_Array_Aggr_Code (Aggr,
          Ctype       => Ctyp,
          Index       => First_Index (Typ),
          Into        => Target,
          Scalar_Comp => Is_Scalar_Type (Ctyp));

      Insert_Actions_After (Decl, Aggr_Code);
   end Convert_Array_Aggr_In_Allocator;

   ----------------------------
   -- Convert_To_Assignments --
   ----------------------------

   procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
      Loc  : constant Source_Ptr := Sloc (N);
      T    : Entity_Id;
      Temp : Entity_Id;

      Instr       : Node_Id;
      Target_Expr : Node_Id;
      Parent_Kind : Node_Kind;
      Unc_Decl    : Boolean := False;
      Parent_Node : Node_Id;

   begin
      pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
      pragma Assert (Is_Record_Type (Typ));

      Parent_Node := Parent (N);
      Parent_Kind := Nkind (Parent_Node);

      if Parent_Kind = N_Qualified_Expression then

         --  Check if we are in a unconstrained declaration because in this
         --  case the current delayed expansion mechanism doesn't work when
         --  the declared object size depend on the initializing expr.

         begin
            Parent_Node := Parent (Parent_Node);
            Parent_Kind := Nkind (Parent_Node);

            if Parent_Kind = N_Object_Declaration then
               Unc_Decl :=
                 not Is_Entity_Name (Object_Definition (Parent_Node))
                   or else Has_Discriminants
                             (Entity (Object_Definition (Parent_Node)))
                   or else Is_Class_Wide_Type
                             (Entity (Object_Definition (Parent_Node)));
            end if;
         end;
      end if;

      --  Just set the Delay flag in the cases where the transformation will be
      --  done top down from above.

      if False

         --  Internal aggregate (transformed when expanding the parent)

         or else Parent_Kind = N_Aggregate
         or else Parent_Kind = N_Extension_Aggregate
         or else Parent_Kind = N_Component_Association

         --  Allocator (see Convert_Aggr_In_Allocator)

         or else Parent_Kind = N_Allocator

         --  Object declaration (see Convert_Aggr_In_Object_Decl)

         or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)

         --  Safe assignment (see Convert_Aggr_Assignments). So far only the
         --  assignments in init procs are taken into account.

         or else (Parent_Kind = N_Assignment_Statement
                   and then Inside_Init_Proc)

         --  (Ada 2005) An inherently limited type in a return statement,
         --  which will be handled in a build-in-place fashion, and may be
         --  rewritten as an extended return and have its own finalization
         --  machinery. In the case of a simple return, the aggregate needs
         --  to be delayed until the scope for the return statement has been
         --  created, so that any finalization chain will be associated with
         --  that scope. For extended returns, we delay expansion to avoid the
         --  creation of an unwanted transient scope that could result in
         --  premature finalization of the return object (which is built in
         --  in place within the caller's scope).

         or else
           (Is_Immutably_Limited_Type (Typ)
             and then
               (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
                 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
      then
         Set_Expansion_Delayed (N);
         return;
      end if;

      if Requires_Transient_Scope (Typ) then
         Establish_Transient_Scope
           (N, Sec_Stack =>
                 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
      end if;

      --  If the aggregate is non-limited, create a temporary. If it is limited
      --  and the context is an assignment, this is a subaggregate for an
      --  enclosing aggregate being expanded. It must be built in place, so use
      --  the target of the current assignment.

      if Is_Limited_Type (Typ)
        and then Nkind (Parent (N)) = N_Assignment_Statement
      then
         Target_Expr := New_Copy_Tree (Name (Parent (N)));
         Insert_Actions (Parent (N),
           Build_Record_Aggr_Code (N, Typ, Target_Expr));
         Rewrite (Parent (N), Make_Null_Statement (Loc));

      else
         Temp := Make_Temporary (Loc, 'A', N);

         --  If the type inherits unknown discriminants, use the view with
         --  known discriminants if available.

         if Has_Unknown_Discriminants (Typ)
            and then Present (Underlying_Record_View (Typ))
         then
            T := Underlying_Record_View (Typ);
         else
            T := Typ;
         end if;

         Instr :=
           Make_Object_Declaration (Loc,
             Defining_Identifier => Temp,
             Object_Definition   => New_Occurrence_Of (T, Loc));

         Set_No_Initialization (Instr);
         Insert_Action (N, Instr);
         Initialize_Discriminants (Instr, T);
         Target_Expr := New_Occurrence_Of (Temp, Loc);
         Insert_Actions (N, Build_Record_Aggr_Code (N, T, Target_Expr));
         Rewrite (N, New_Occurrence_Of (Temp, Loc));
         Analyze_And_Resolve (N, T);
      end if;
   end Convert_To_Assignments;

   ---------------------------
   -- Convert_To_Positional --
   ---------------------------

   procedure Convert_To_Positional
     (N                    : Node_Id;
      Max_Others_Replicate : Nat     := 5;
      Handle_Bit_Packed    : Boolean := False)
   is
      Typ : constant Entity_Id := Etype (N);

      Static_Components : Boolean := True;

      procedure Check_Static_Components;
      --  Check whether all components of the aggregate are compile-time known
      --  values, and can be passed as is to the back-end without further
      --  expansion.

      function Flatten
        (N   : Node_Id;
         Ix  : Node_Id;
         Ixb : Node_Id) return Boolean;
      --  Convert the aggregate into a purely positional form if possible. On
      --  entry the bounds of all dimensions are known to be static, and the
      --  total number of components is safe enough to expand.

      function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
      --  Return True iff the array N is flat (which is not trivial in the case
      --  of multidimensional aggregates).

      -----------------------------
      -- Check_Static_Components --
      -----------------------------

      procedure Check_Static_Components is
         Expr : Node_Id;

      begin
         Static_Components := True;

         if Nkind (N) = N_String_Literal then
            null;

         elsif Present (Expressions (N)) then
            Expr := First (Expressions (N));
            while Present (Expr) loop
               if Nkind (Expr) /= N_Aggregate
                 or else not Compile_Time_Known_Aggregate (Expr)
                 or else Expansion_Delayed (Expr)
               then
                  Static_Components := False;
                  exit;
               end if;

               Next (Expr);
            end loop;
         end if;

         if Nkind (N) = N_Aggregate
           and then  Present (Component_Associations (N))
         then
            Expr := First (Component_Associations (N));
            while Present (Expr) loop
               if Nkind_In (Expression (Expr), N_Integer_Literal,
                                               N_Real_Literal)
               then
                  null;

               elsif Is_Entity_Name (Expression (Expr))
                 and then Present (Entity (Expression (Expr)))
                 and then Ekind (Entity (Expression (Expr))) =
                   E_Enumeration_Literal
               then
                  null;

               elsif Nkind (Expression (Expr)) /= N_Aggregate
                 or else not Compile_Time_Known_Aggregate (Expression (Expr))
                 or else Expansion_Delayed (Expression (Expr))
               then
                  Static_Components := False;
                  exit;
               end if;

               Next (Expr);
            end loop;
         end if;
      end Check_Static_Components;

      -------------
      -- Flatten --
      -------------

      function Flatten
        (N   : Node_Id;
         Ix  : Node_Id;
         Ixb : Node_Id) return Boolean
      is
         Loc : constant Source_Ptr := Sloc (N);
         Blo : constant Node_Id    := Type_Low_Bound (Etype (Ixb));
         Lo  : constant Node_Id    := Type_Low_Bound (Etype (Ix));
         Hi  : constant Node_Id    := Type_High_Bound (Etype (Ix));
         Lov : Uint;
         Hiv : Uint;

         Others_Present : Boolean := False;

      begin
         if Nkind (Original_Node (N)) = N_String_Literal then
            return True;
         end if;

         if not Compile_Time_Known_Value (Lo)
           or else not Compile_Time_Known_Value (Hi)
         then
            return False;
         end if;

         Lov := Expr_Value (Lo);
         Hiv := Expr_Value (Hi);

         --  Check if there is an others choice

         if Present (Component_Associations (N)) then
            declare
               Assoc   : Node_Id;
               Choice  : Node_Id;

            begin
               Assoc := First (Component_Associations (N));
               while Present (Assoc) loop

                  --  If this is a box association, flattening is in general
                  --  not possible because at this point we cannot tell if the
                  --  default is static or even exists.

                  if Box_Present (Assoc) then
                     return False;
                  end if;

                  Choice := First (Choices (Assoc));

                  while Present (Choice) loop
                     if Nkind (Choice) = N_Others_Choice then
                        Others_Present := True;
                     end if;

                     Next (Choice);
                  end loop;

                  Next (Assoc);
               end loop;
            end;
         end if;

         --  If the low bound is not known at compile time and others is not
         --  present we can proceed since the bounds can be obtained from the
         --  aggregate.

         --  Note: This case is required in VM platforms since their backends
         --  normalize array indexes in the range 0 .. N-1. Hence, if we do
         --  not flat an array whose bounds cannot be obtained from the type
         --  of the index the backend has no way to properly generate the code.
         --  See ACATS c460010 for an example.

         if Hiv < Lov
           or else (not Compile_Time_Known_Value (Blo)
                     and then Others_Present)
         then
            return False;
         end if;

         --  Determine if set of alternatives is suitable for conversion and
         --  build an array containing the values in sequence.

         declare
            Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
                     of Node_Id := (others => Empty);
            --  The values in the aggregate sorted appropriately

            Vlist : List_Id;
            --  Same data as Vals in list form

            Rep_Count : Nat;
            --  Used to validate Max_Others_Replicate limit

            Elmt         : Node_Id;
            Num          : Int := UI_To_Int (Lov);
            Choice_Index : Int;
            Choice       : Node_Id;
            Lo, Hi       : Node_Id;

         begin
            if Present (Expressions (N)) then
               Elmt := First (Expressions (N));
               while Present (Elmt) loop
                  if Nkind (Elmt) = N_Aggregate
                    and then Present (Next_Index (Ix))
                    and then
                      not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
                  then
                     return False;
                  end if;

                  Vals (Num) := Relocate_Node (Elmt);
                  Num := Num + 1;

                  Next (Elmt);
               end loop;
            end if;

            if No (Component_Associations (N)) then
               return True;
            end if;

            Elmt := First (Component_Associations (N));

            if Nkind (Expression (Elmt)) = N_Aggregate then
               if Present (Next_Index (Ix))
                 and then
                   not Flatten
                        (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
               then
                  return False;
               end if;
            end if;

            Component_Loop : while Present (Elmt) loop
               Choice := First (Choices (Elmt));
               Choice_Loop : while Present (Choice) loop

                  --  If we have an others choice, fill in the missing elements
                  --  subject to the limit established by Max_Others_Replicate.

                  if Nkind (Choice) = N_Others_Choice then
                     Rep_Count := 0;

                     for J in Vals'Range loop
                        if No (Vals (J)) then
                           Vals (J) := New_Copy_Tree (Expression (Elmt));
                           Rep_Count := Rep_Count + 1;

                           --  Check for maximum others replication. Note that
                           --  we skip this test if either of the restrictions
                           --  No_Elaboration_Code or No_Implicit_Loops is
                           --  active, if this is a preelaborable unit or a
                           --  predefined unit. This ensures that predefined
                           --  units get the same level of constant folding in
                           --  Ada 95 and Ada 2005, where their categorization
                           --  has changed.

                           declare
                              P : constant Entity_Id :=
                                    Cunit_Entity (Current_Sem_Unit);

                           begin
                              --  Check if duplication OK and if so continue
                              --  processing.

                              if Restriction_Active (No_Elaboration_Code)
                                or else Restriction_Active (No_Implicit_Loops)
                                or else Is_Preelaborated (P)
                                or else (Ekind (P) = E_Package_Body
                                          and then
                                            Is_Preelaborated (Spec_Entity (P)))
                                or else
                                  Is_Predefined_File_Name
                                    (Unit_File_Name (Get_Source_Unit (P)))
                              then
                                 null;

                              --  If duplication not OK, then we return False
                              --  if the replication count is too high

                              elsif Rep_Count > Max_Others_Replicate then
                                 return False;

                              --  Continue on if duplication not OK, but the
                              --  replication count is not excessive.

                              else
                                 null;
                              end if;
                           end;
                        end if;
                     end loop;

                     exit Component_Loop;

                  --  Case of a subtype mark, identifier or expanded name

                  elsif Is_Entity_Name (Choice)
                    and then Is_Type (Entity (Choice))
                  then
                     Lo := Type_Low_Bound  (Etype (Choice));
                     Hi := Type_High_Bound (Etype (Choice));

                  --  Case of subtype indication

                  elsif Nkind (Choice) = N_Subtype_Indication then
                     Lo := Low_Bound  (Range_Expression (Constraint (Choice)));
                     Hi := High_Bound (Range_Expression (Constraint (Choice)));

                  --  Case of a range

                  elsif Nkind (Choice) = N_Range then
                     Lo := Low_Bound (Choice);
                     Hi := High_Bound (Choice);

                  --  Normal subexpression case

                  else pragma Assert (Nkind (Choice) in N_Subexpr);
                     if not Compile_Time_Known_Value (Choice) then
                        return False;

                     else
                        Choice_Index := UI_To_Int (Expr_Value (Choice));
                        if Choice_Index in Vals'Range then
                           Vals (Choice_Index) :=
                             New_Copy_Tree (Expression (Elmt));
                           goto Continue;

                        else
                           --  Choice is statically out-of-range, will be
                           --  rewritten to raise Constraint_Error.

                           return False;
                        end if;
                     end if;
                  end if;

                  --  Range cases merge with Lo,Hi set

                  if not Compile_Time_Known_Value (Lo)
                       or else
                     not Compile_Time_Known_Value (Hi)
                  then
                     return False;
                  else
                     for J in UI_To_Int (Expr_Value (Lo)) ..
                              UI_To_Int (Expr_Value (Hi))
                     loop
                        Vals (J) := New_Copy_Tree (Expression (Elmt));
                     end loop;
                  end if;

               <<Continue>>
                  Next (Choice);
               end loop Choice_Loop;

               Next (Elmt);
            end loop Component_Loop;

            --  If we get here the conversion is possible

            Vlist := New_List;
            for J in Vals'Range loop
               Append (Vals (J), Vlist);
            end loop;

            Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
            Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
            return True;
         end;
      end Flatten;

      -------------
      -- Is_Flat --
      -------------

      function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
         Elmt : Node_Id;

      begin
         if Dims = 0 then
            return True;

         elsif Nkind (N) = N_Aggregate then
            if Present (Component_Associations (N)) then
               return False;

            else
               Elmt := First (Expressions (N));
               while Present (Elmt) loop
                  if not Is_Flat (Elmt, Dims - 1) then
                     return False;
                  end if;

                  Next (Elmt);
               end loop;

               return True;
            end if;
         else
            return True;
         end if;
      end Is_Flat;

   --  Start of processing for Convert_To_Positional