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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ A G G R --
-- --
-- B o d y --
-- --
-- $Revision$
-- --
-- Copyright (C) 1992-2001 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Expander; use Expander;
with Exp_Util; use Exp_Util;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch7; use Exp_Ch7;
with Freeze; use Freeze;
with Hostparm; use Hostparm;
with Itypes; use Itypes;
with Nmake; use Nmake;
with Nlists; use Nlists;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
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 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
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 --
------------------------------------------------------
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
procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
-- N is an N_Aggregate of a N_Extension_Aggregate. Typ is the type of
-- the aggregate. Transform the given aggregate into a sequence of
-- assignments component per component.
function Build_Record_Aggr_Code
(N : Node_Id;
Typ : Entity_Id;
Target : Node_Id;
Flist : Node_Id := Empty;
Obj : Entity_Id := Empty)
return List_Id;
-- N is an N_Aggregate or a 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. Flist is an
-- expression representing the finalization list on which to
-- attach the controlled components if any. Obj is present in the
-- object declaration and dynamic allocation cases, it contains
-- an entity that allows to know if the value being created needs to be
-- attached to the final list in case of pragma finalize_Storage_Only.
-----------------------------------------------------
-- Local subprograms for array aggregate expansion --
-----------------------------------------------------
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 Backend_Processing_Possible (N : Node_Id) return Boolean;
-- This function checks if array aggregate N can be processed directly
-- by Gigi. If this is the case True is returned.
function Build_Array_Aggr_Code
(N : Node_Id;
Index : Node_Id;
Into : Node_Id;
Scalar_Comp : Boolean;
Indices : List_Id := No_List;
Flist : Node_Id := Empty)
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.
--
-- Index is the index node corresponding to the array sub-aggregate N.
--
-- Into is the target expression into which we are copying the aggregate.
--
-- Scalar_Comp is True if the component type of the aggregate is scalar.
--
-- Indices is the current list of expressions used to index the
-- object we are writing into.
--
-- Flist is an expression representing the finalization list on which
-- to attach the controlled components if any.
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 Late_Expansion
(N : Node_Id;
Typ : Entity_Id;
Target : Node_Id;
Flist : Node_Id := Empty;
Obj : Entity_Id := Empty)
return List_Id;
-- N is a nested (record or array) aggregate that has been marked
-- with 'Delay_Expansion'. Typ is the expected type of the
-- aggregate and Target is a (duplicable) expression that will
-- hold the result of the aggregate expansion. Flist is the
-- finalization list to be used to attach controlled
-- components. 'Obj' when non empty, carries the original object
-- being initialized in order to know if it needs to be attached
-- to the previous parameter which may not be the case when
-- Finalize_Storage_Only is set. Basically this procedure is used
-- to implement top-down expansions of nested aggregates. This is
-- necessary for avoiding temporaries at each level as well as for
-- propagating the right internal finalization list.
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 Safe_Slice_Assignment
(N : Node_Id;
Typ : Entity_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.
---------------------------------
-- 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 is tagged, which may necessitate
-- reassignment of proper tags.
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 Static_Check (N : Node_Id; Index : Node_Id) return Boolean;
-- Recursively checks that N is fully positional, returns true if so.
------------------
-- Static_Check --
------------------
function Static_Check (N : Node_Id; Index : Node_Id) return Boolean is
Expr : Node_Id;
begin
-- Check for component associations
if Present (Component_Associations (N)) then
return False;
end if;
-- Recurse to check subaggregates, which may appear in qualified
-- expressions. If delayed, the front-end will have to expand.
Expr := First (Expressions (N));
while Present (Expr) loop
if Is_Delayed_Aggregate (Expr) then
return False;
end if;
if Present (Next_Index (Index))
and then not Static_Check (Expr, Next_Index (Index))
then
return False;
end if;
Next (Expr);
end loop;
return True;
end Static_Check;
-- Start of processing for Backend_Processing_Possible
begin
-- Checks 2 (array must not be bit packed)
if Is_Bit_Packed_Array (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 1 (aggregate must be fully positional)
if not Static_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, along the lines of the test that's
-- done in Has_Delayed_Nested_Aggregate_Or_Tagged_Comps
-- 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 not Java_VM then
return False;
end if;
-- Backend processing is possible
Set_Compile_Time_Known_Aggregate (N, True);
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:
-- I : Index_Type := Index_Of_Last_Positional_Element;
-- while I < H loop
-- I := Index_Base'Succ (I)
-- Tmp (I) := E;
-- end loop;
function Build_Array_Aggr_Code
(N : Node_Id;
Index : Node_Id;
Into : Node_Id;
Scalar_Comp : Boolean;
Indices : List_Id := No_List;
Flist : Node_Id := Empty)
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,
-- This routine returns the assignment statement
--
-- Into (Indices, Ind) := Expr;
--
-- Otherwise we call Build_Code recursively.
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 (Indices, 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
--
-- I : Index_Base := L;
-- while I < H loop
-- I := Index_Base'Succ (I);
-- Into (Indices, I) := 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 : 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 : List_Id := New_List;
F : Entity_Id;
A : Node_Id;
New_Indices : 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
if 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 (Indices) then
New_Indices := New_List;
else
New_Indices := New_Copy_List_Tree (Indices);
end if;
Append_To (New_Indices, Ind);
if Present (Flist) then
F := New_Copy_Tree (Flist);
elsif Present (Etype (N)) and then Controlled_Type (Etype (N)) then
if Is_Entity_Name (Into)
and then Present (Scope (Entity (Into)))
then
F := Find_Final_List (Scope (Entity (Into)));
else
F := Find_Final_List (Current_Scope);
end if;
else
F := 0;
end if;
if Present (Next_Index (Index)) then
return
Add_Loop_Actions (
Build_Array_Aggr_Code
(Expr, Next_Index (Index),
Into, Scalar_Comp, New_Indices, F));
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_Indices));
Set_Assignment_OK (Indexed_Comp);
if 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));
elsif Present (Next (First (New_Indices))) 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 := Parent (Expr);
begin
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;
end;
end if;
if (Nkind (Expr_Q) = N_Aggregate
or else Nkind (Expr_Q) = 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's 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
return
Add_Loop_Actions (
Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp, F));
end if;
end if;
-- 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 Controlled_Type (Comp_Type) then
Set_No_Ctrl_Actions (A);
end if;
Append_To (L, A);
-- Adjust the tag if tagged (because of possible view
-- conversions), unless compiling for the Java VM
-- where tags are implicit.
if Present (Comp_Type)
and then Is_Tagged_Type (Comp_Type)
and then not Java_VM
then
A :=
Make_OK_Assignment_Statement (Loc,
Name =>
Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Indexed_Comp),
Selector_Name =>
New_Reference_To (Tag_Component (Comp_Type), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (
Access_Disp_Table (Comp_Type), Loc)));
Append_To (L, A);
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 Present (Comp_Type) and then Controlled_Type (Comp_Type) then
Append_List_To (L,
Make_Adjust_Call (
Ref => New_Copy_Tree (Indexed_Comp),
Typ => Comp_Type,
Flist_Ref => F,
With_Attach => Make_Integer_Literal (Loc, 1)));
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_I : Node_Id;
L_Range : Node_Id;
-- Index_Base'(L) .. Index_Base'(H)
L_Iteration_Scheme : Node_Id;
-- L_I in Index_Base'(L) .. Index_Base'(H)
L_Body : List_Id;
-- The statements to execute in the loop
S : List_Id := New_List;
-- list of statement
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));
-- 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;
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_I
L_I := Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
-- Construct "L .. H"
L_Range :=
Make_Range
(Loc,
Low_Bound => Make_Qualified_Expression
(Loc,
Subtype_Mark => Index_Base_Name,
Expression => L),
High_Bound => Make_Qualified_Expression
(Loc,
Subtype_Mark => Index_Base_Name,
Expression => H));
-- Construct "for L_I in Index_Base range L .. H"
L_Iteration_Scheme :=
Make_Iteration_Scheme
(Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification
(Loc,
Defining_Identifier => L_I,
Discrete_Subtype_Definition => L_Range));
-- Construct the statements to execute in the loop body
L_Body := Gen_Assign (New_Reference_To (L_I, 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));
return S;
end Gen_Loop;
---------------
-- Gen_While --
---------------
-- The code built is
-- W_I : Index_Base := L;
-- while W_I < H loop
-- W_I := Index_Base'Succ (W);
-- L_Body;
-- end loop;
function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
W_I : Node_Id;
W_Decl : Node_Id;
-- W_I : Base_Type := L;
W_Iteration_Scheme : Node_Id;
-- while W_I < H
W_Index_Succ : Node_Id;
-- Index_Base'Succ (I)
W_Increment : Node_Id;
-- W_I := Index_Base'Succ (W)
W_Body : List_Id := New_List;
-- The statements to execute in the loop
S : 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_I
W_I := Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
W_Decl :=
Make_Object_Declaration
(Loc,
Defining_Identifier => W_I,
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_I < H"
W_Iteration_Scheme :=
Make_Iteration_Scheme
(Loc,
Condition => Make_Op_Lt
(Loc,
Left_Opnd => New_Reference_To (W_I, 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_I, Loc)));
W_Increment :=
Make_OK_Assignment_Statement
(Loc,
Name => New_Reference_To (W_I, Loc),
Expression => W_Index_Succ);
Append_To (W_Body, W_Increment);
Append_List_To (W_Body,
Gen_Assign (New_Reference_To (W_I, 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;
Others_Expr : Node_Id := Empty;
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 (Aggr_L);
Aggr_High : constant Node_Id := Duplicate_Subexpr (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 : List_Id := New_List;
-- Start of processing for Build_Array_Aggr_Code
begin
-- STEP 1: Process 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
Others_Expr := Expression (Assoc);
exit;
end if;
Get_Index_Bounds (Choice, Low, High);
Nb_Choices := Nb_Choices + 1;
Table (Nb_Choices) := (Choice_Lo => Low,
Choice_Hi => High,
Choice_Node => Expression (Assoc));
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) 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));
Expr := Expression (Assoc);
Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
Aggr_High,
Expr),
To => New_Code);
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;
Target : Node_Id;
Flist : Node_Id := Empty;
Obj : Entity_Id := Empty)
return List_Id
is
Loc : constant Source_Ptr := Sloc (N);
L : constant List_Id := New_List;
Start_L : constant List_Id := New_List;
N_Typ : constant Entity_Id := Etype (N);
Comp : Node_Id;
Instr : Node_Id;
Ref : Node_Id;
F : Node_Id;
Comp_Type : Entity_Id;
Selector : Entity_Id;
Comp_Expr : Node_Id;
Comp_Kind : Node_Kind;
Expr_Q : Node_Id;
Internal_Final_List : 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.
External_Final_List : Node_Id;
Ancestor_Is_Expression : Boolean := False;
Ancestor_Is_Subtype_Mark : Boolean := False;
Init_Typ : Entity_Id := Empty;
Attach : Node_Id;
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.
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 Init_Controller
(Target : Node_Id;
Typ : Entity_Id;
F : Node_Id;
Attach : Node_Id;
Init_Pr : Boolean)
return List_Id;
-- returns the list of statements necessary to initialize the internal
-- controller of the (possible) ancestor typ into target and attach
-- it to finalization list F. Init_Pr conditions the call to the
-- init_proc since it may already be done due to ancestor initialization
---------------------------------
-- 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) 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 := First_Discriminant (Base_Type (Anc_Typ));
Disc_Value : Node_Id;
Cond : Node_Id;
begin
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));
end if;
Next_Discriminant (Discr);
end loop;
end Check_Ancestor_Discriminants;
--------------------------------
-- Get_Constraint_Association --
--------------------------------
function Get_Constraint_Association (T : Entity_Id) return Node_Id is
Typ_Def : constant Node_Id := Type_Definition (Parent (T));
Indic : constant Node_Id := Subtype_Indication (Typ_Def);
begin
-- ??? 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_controller --
---------------------
function Init_Controller
(Target : Node_Id;
Typ : Entity_Id;
F : Node_Id;
Attach : Node_Id;
Init_Pr : Boolean)
return List_Id
is
Ref : Node_Id;
L : List_Id := New_List;
begin
-- _init_proc (target._controller);
-- initialize (target._controller);
-- Attach_to_Final_List (target._controller, F);
Ref := Make_Selected_Component (Loc,
Prefix => Convert_To (Typ, New_Copy_Tree (Target)),
Selector_Name => Make_Identifier (Loc, Name_uController));
Set_Assignment_OK (Ref);
if Init_Pr then
Append_List_To (L,
Build_Initialization_Call (Loc,
Id_Ref => Ref,
Typ => RTE (RE_Record_Controller),
In_Init_Proc => Within_Init_Proc));
end if;
Append_To (L,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (Find_Prim_Op (RTE (RE_Record_Controller),
Name_Initialize), Loc),
Parameter_Associations => New_List (New_Copy_Tree (Ref))));
Append_To (L,
Make_Attach_Call (
Obj_Ref => New_Copy_Tree (Ref),
Flist_Ref => F,
With_Attach => Attach));
return L;
end Init_Controller;
-- Start of processing for Build_Record_Aggr_Code
begin
-- Deal with the ancestor part of extension aggregates
-- or with the discriminants of the root type
if Nkind (N) = N_Extension_Aggregate then
declare
A : constant Node_Id := Ancestor_Part (N);
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 (A) and then Is_Type (Entity (A)) then
Ancestor_Is_Subtype_Mark := True;
if Is_Constrained (Entity (A)) then
Init_Typ := Entity (A);
-- 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 (A)) then
declare
Anc_Typ : Entity_Id := Entity (A);
Discrim : Entity_Id := First_Discriminant (Anc_Typ);
Anc_Constr : List_Id := New_List;
Disc_Value : Node_Id;
New_Indic : Node_Id;
Subt_Decl : Node_Id;
begin
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
Analyze (Subt_Decl, Suppress => All_Checks);
end;
end if;
Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
Set_Assignment_OK (Ref);
Append_List_To (Start_L,
Build_Initialization_Call (Loc,
Id_Ref => Ref,
Typ => Init_Typ,
In_Init_Proc => Within_Init_Proc));
if Is_Constrained (Entity (A))
and then Has_Discriminants (Entity (A))
then
Check_Ancestor_Discriminants (Entity (A));
end if;
-- If the ancestor part is an expression "E", we generate
-- T(tmp) := E;
else
Ancestor_Is_Expression := True;
Init_Typ := Etype (A);
-- Assign the tag before doing the assignment to make sure
-- that the dispatching call in the subsequent deep_adjust
-- works properly (unless Java_VM, where tags are implicit).
if not Java_VM then
Instr :=
Make_OK_Assignment_Statement (Loc,
Name =>
Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Target),
Selector_Name => New_Reference_To (
Tag_Component (Base_Type (Typ)), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (
Access_Disp_Table (Base_Type (Typ)), Loc)));
Set_Assignment_OK (Name (Instr));
Append_To (L, Instr);
end if;
-- If the ancestor part is an aggregate, force its full
-- expansion, which was delayed.
if Nkind (A) = N_Qualified_Expression
and then (Nkind (Expression (A)) = N_Aggregate
or else
Nkind (Expression (A)) = N_Extension_Aggregate)
then
Set_Analyzed (A, False);
Set_Analyzed (Expression (A), False);
end if;
Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
Set_Assignment_OK (Ref);
Append_To (L,
Make_Unsuppress_Block (Loc,
Name_Discriminant_Check,
New_List (
Make_OK_Assignment_Statement (Loc,
Name => Ref,
Expression => A))));
if Has_Discriminants (Init_Typ) then
Check_Ancestor_Discriminants (Init_Typ);
end if;
end if;
end;
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
-- ??? The discriminants of the object not inherited in the type
-- of the object should be initialized here
null;
-- Generate discriminant init values
declare
Discriminant : Entity_Id;
Discriminant_Value : Node_Id;
begin
Discriminant := First_Girder_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_Girder_Discriminant (Discriminant);
end loop;
end;
end if;
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)));
if Ekind (Selector) /= E_Discriminant
or else Nkind (N) = N_Extension_Aggregate
then
Comp_Type := Etype (Selector);
Comp_Kind := Nkind (Expression (Comp));
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;
-- The controller is the one of the parent type defining
-- the component (in case of inherited components).
if Controlled_Type (Comp_Type) then
Internal_Final_List :=
Make_Selected_Component (Loc,
Prefix => Convert_To (
Scope (Original_Record_Component (Selector)),
New_Copy_Tree (Target)),
Selector_Name =>
Make_Identifier (Loc, Name_uController));
Internal_Final_List :=
Make_Selected_Component (Loc,
Prefix => Internal_Final_List,
Selector_Name => Make_Identifier (Loc, Name_F));
-- The internal final list can be part of a constant object
Set_Assignment_OK (Internal_Final_List);
else
Internal_Final_List := Empty;
end if;
if Is_Delayed_Aggregate (Expr_Q) then
Append_List_To (L,
Late_Expansion (Expr_Q, Comp_Type, Comp_Expr,
Internal_Final_List));
else
Instr :=
Make_OK_Assignment_Statement (Loc,
Name => Comp_Expr,
Expression => Expression (Comp));
Set_No_Ctrl_Actions (Instr);
Append_To (L, Instr);
-- Adjust the tag if tagged (because of possible view
-- conversions), unless compiling for the Java VM
-- where tags are implicit.
-- tmp.comp._tag := comp_typ'tag;
if Is_Tagged_Type (Comp_Type) and then not Java_VM then
Instr :=
Make_OK_Assignment_Statement (Loc,
Name =>
Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Comp_Expr),
Selector_Name =>
New_Reference_To (Tag_Component (Comp_Type), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (
Access_Disp_Table (Comp_Type), Loc)));
Append_To (L, Instr);
end if;
-- Adjust and Attach the component to the proper controller
-- Adjust (tmp.comp);
-- Attach_To_Final_List (tmp.comp,
-- comp_typ (tmp)._record_controller.f)
if Controlled_Type (Comp_Type) then
Append_List_To (L,
Make_Adjust_Call (
Ref => New_Copy_Tree (Comp_Expr),
Typ => Comp_Type,
Flist_Ref => Internal_Final_List,
With_Attach => Make_Integer_Literal (Loc, 1)));
end if;
end if;
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;
elsif Is_Tagged_Type (Typ) and then not Java_VM then
Instr :=
Make_OK_Assignment_Statement (Loc,
Name =>
Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Target),
Selector_Name =>
New_Reference_To (Tag_Component (Base_Type (Typ)), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (Access_Disp_Table (Base_Type (Typ)), Loc)));
Append_To (L, Instr);
end if;
-- Now deal with the various controlled type data structure
-- initializations
if Present (Obj)
and then Finalize_Storage_Only (Typ)
and then (Is_Library_Level_Entity (Obj)
or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
= Standard_True)
then
Attach := Make_Integer_Literal (Loc, 0);
elsif Nkind (Parent (N)) = N_Qualified_Expression
and then Nkind (Parent (Parent (N))) = N_Allocator
then
Attach := Make_Integer_Literal (Loc, 2);
else
Attach := Make_Integer_Literal (Loc, 1);
end if;
-- 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 Controlled_Type (Typ) then
if Present (Flist) then
External_Final_List := New_Copy_Tree (Flist);
elsif Is_Entity_Name (Target)
and then Present (Scope (Entity (Target)))
then
External_Final_List := Find_Final_List (Scope (Entity (Target)));
else
External_Final_List := Find_Final_List (Current_Scope);
end if;
else
External_Final_List := Empty;
end if;
-- initialize and attach the outer object in the is_controlled
-- case
if Is_Controlled (Typ) then
if 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;
-- ??? when the ancestor part is an expression, the global
-- object is already attached at the wrong level. It should
-- be detached and re-attached. We have a design problem here.
if Ancestor_Is_Expression
and then Has_Controlled_Component (Init_Typ)
then
null;
elsif Has_Controlled_Component (Typ) then
F := Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Target),
Selector_Name => Make_Identifier (Loc, Name_uController));
F := Make_Selected_Component (Loc,
Prefix => F,
Selector_Name => Make_Identifier (Loc, Name_F));
Ref := New_Copy_Tree (Target);
Set_Assignment_OK (Ref);
Append_To (L,
Make_Attach_Call (
Obj_Ref => Ref,
Flist_Ref => F,
With_Attach => Make_Integer_Literal (Loc, 1)));
else -- is_Controlled (Typ) and not Has_Controlled_Component (Typ)
Ref := New_Copy_Tree (Target);
Set_Assignment_OK (Ref);
Append_To (Start_L,
Make_Attach_Call (
Obj_Ref => Ref,
Flist_Ref => New_Copy_Tree (External_Final_List),
With_Attach => Attach));
end if;
end if;
-- in the Has_Controlled component case, all the intermediate
-- controllers must be initialized
if Has_Controlled_Component (Typ) then
declare
Inner_Typ : Entity_Id;
Outer_Typ : Entity_Id;
At_Root : Boolean;
begin
Outer_Typ := Base_Type (Typ);
-- find outer type with a controller
while Outer_Typ /= Init_Typ
and then not Has_New_Controlled_Component (Outer_Typ)
loop
Outer_Typ := Etype (Outer_Typ);
end loop;
-- attach it to the outer record controller to the
-- external final list
if Outer_Typ = Init_Typ then
Append_List_To (Start_L,
Init_Controller (
Target => Target,
Typ => Outer_Typ,
F => External_Final_List,
Attach => Attach,
Init_Pr => Ancestor_Is_Expression));
At_Root := True;
Inner_Typ := Init_Typ;
else
Append_List_To (Start_L,
Init_Controller (
Target => Target,
Typ => Outer_Typ,
F => External_Final_List,
Attach => Attach,
Init_Pr => True));
Inner_Typ := Etype (Outer_Typ);
At_Root :=
not Is_Tagged_Type (Typ) or else Inner_Typ = Outer_Typ;
end if;
-- Initialize the internal controllers for tagged types with
-- more than one controller.
while not At_Root and then Inner_Typ /= Init_Typ loop
if Has_New_Controlled_Component (Inner_Typ) then
F :=
Make_Selected_Component (Loc,
Prefix => Convert_To (Outer_Typ, New_Copy_Tree (Target)),
Selector_Name =>
Make_Identifier (Loc, Name_uController));
F := Make_Selected_Component (Loc,
Prefix => F,
Selector_Name => Make_Identifier (Loc, Name_F));
Append_List_To (Start_L,
Init_Controller (
Target => Target,
Typ => Inner_Typ,
F => F,
Attach => Make_Integer_Literal (Loc, 1),
Init_Pr => True));
Outer_Typ := Inner_Typ;
end if;
-- Stop at the root
At_Root := Inner_Typ = Etype (Inner_Typ);
Inner_Typ := Etype (Inner_Typ);
end loop;
-- if not done yet attach the controller of the ancestor part
if Outer_Typ /= Init_Typ
and then Inner_Typ = Init_Typ
and then Has_Controlled_Component (Init_Typ)
then
F :=
Make_Selected_Component (Loc,
Prefix => Convert_To (Outer_Typ, New_Copy_Tree (Target)),
Selector_Name => Make_Identifier (Loc, Name_uController));
F := Make_Selected_Component (Loc,
Prefix => F,
Selector_Name => Make_Identifier (Loc, Name_F));
Attach := Make_Integer_Literal (Loc, 1);
Append_List_To (Start_L,
Init_Controller (
Target => Target,
Typ => Init_Typ,
F => F,
Attach => Attach,
Init_Pr => Ancestor_Is_Expression));
end if;
end;
end if;
Append_List_To (Start_L, L);
return Start_L;
end Build_Record_Aggr_Code;
-------------------------------
-- Convert_Aggr_In_Allocator --
-------------------------------
procedure Convert_Aggr_In_Allocator (Decl, 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)));
Access_Type : constant Entity_Id := Etype (Temp);
begin
Insert_Actions_After (Decl,
Late_Expansion (Aggr, Typ, Occ,
Find_Final_List (Access_Type),
Associated_Final_Chain (Base_Type (Access_Type))));
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,
Find_Final_List (Typ, New_Copy_Tree (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);
begin
Set_Assignment_OK (Occ);
if Nkind (Aggr) = N_Qualified_Expression then
Aggr := Expression (Aggr);
end if;
Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ, Obj => Obj));
Set_No_Initialization (N);
end Convert_Aggr_In_Object_Decl;
----------------------------
-- Convert_To_Assignments --
----------------------------
procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Temp : Entity_Id;
Instr : Node_Id;
Target_Expr : Node_Id;
Parent_Kind : Node_Kind;
Unc_Decl : Boolean := False;
Parent_Node : Node_Id;
begin
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 following cases where the
-- transformation will be done top down from above
-- - internal aggregate (transformed when expanding the parent)
-- - allocators (see Convert_Aggr_In_Allocator)
-- - object decl (see Convert_Aggr_In_Object_Decl)
-- - safe assignments (see Convert_Aggr_Assignments)
-- so far only the assignments in the init_procs are taken
-- into account
if Parent_Kind = N_Aggregate
or else Parent_Kind = N_Extension_Aggregate
or else Parent_Kind = N_Component_Association
or else Parent_Kind = N_Allocator
or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
or else (Parent_Kind = N_Assignment_Statement
and then Inside_Init_Proc)
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;
-- Create the temporary
Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Instr :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Occurrence_Of (Typ, Loc));
Set_No_Initialization (Instr);
Insert_Action (N, Instr);
Target_Expr := New_Occurrence_Of (Temp, Loc);
Insert_Actions (N, Build_Record_Aggr_Code (N, Typ, Target_Expr));
Rewrite (N, New_Occurrence_Of (Temp, Loc));
Analyze_And_Resolve (N, Typ);
end Convert_To_Assignments;
----------------------------
-- Expand_Array_Aggregate --
----------------------------
-- Array aggregate expansion proceeds as follows:
-- 1. If requested we generate code to perform all the array aggregate
-- bound checks, specifically
-- (a) Check that the index range defined by aggregate bounds is
-- compatible with corresponding index subtype.
-- (b) If an others choice is present check that no aggregate
-- index is outside the bounds of the index constraint.
-- (c) For multidimensional arrays make sure that all subaggregates
-- corresponding to the same dimension have the same bounds.
-- 2. Check if the aggregate can be statically processed. If this is the
-- case pass it as is to Gigi. Note that a necessary condition for
-- static processing is that the aggregate be fully positional.
-- 3. If in place aggregate expansion is possible (i.e. no need to create
-- a temporary) then mark the aggregate as such and return. Otherwise
-- create a new temporary and generate the appropriate initialization
-- code.
procedure Expand_Array_Aggregate (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Ctyp : constant Entity_Id := Component_Type (Typ);
-- Typ is the correct constrained array subtype of the aggregate and
-- Ctyp is the corresponding component type.
Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
-- Number of aggregate index dimensions.
Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
-- Low and High bounds of the constraint for each aggregate index.
Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
-- The type of each index.
Maybe_In_Place_OK : Boolean;
-- If the type is neither controlled nor packed and the aggregate
-- is the expression in an assignment, assignment in place may be
-- possible, provided other conditions are met on the LHS.
Others_Present : array (1 .. Aggr_Dimension) of Boolean
:= (others => False);
-- If Others_Present (I) is True, then there is an others choice
-- in one of the sub-aggregates of N at dimension I.
procedure Build_Constrained_Type (Positional : Boolean);
-- If the subtype is not static or unconstrained, build a constrained
-- type using the computable sizes of the aggregate and its sub-
-- aggregates.
procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
-- Checks that the bounds of Aggr_Bounds are within the bounds defined
-- by Index_Bounds.
procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
-- Checks that in a multi-dimensional array aggregate all subaggregates
-- corresponding to the same dimension have the same bounds.
-- Sub_Aggr is an array sub-aggregate. Dim is the dimension
-- corresponding to the sub-aggregate.
procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
-- Computes the values of array Others_Present. Sub_Aggr is the
-- array sub-aggregate we start the computation from. Dim is the
-- dimension corresponding to the sub-aggregate.
procedure Convert_To_Positional (N : Node_Id);
-- 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.
function Has_Address_Clause (D : Node_Id) return Boolean;
-- If the aggregate is the expression in an object declaration, it
-- cannot be expanded in place. This function does a lookahead in the
-- current declarative part to find an address clause for the object
-- being declared.
function In_Place_Assign_OK return Boolean;
-- Simple predicate to determine whether an aggregate assignment can
-- be done in place, because none of the new values can depend on the
-- components of the target of the assignment.
procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
-- Checks that if an others choice is present in any sub-aggregate no
-- aggregate index is outside the bounds of the index constraint.
-- Sub_Aggr is an array sub-aggregate. Dim is the dimension
-- corresponding to the sub-aggregate.
----------------------------
-- Build_Constrained_Type --
----------------------------
procedure Build_Constrained_Type (Positional : Boolean) is
Loc : constant Source_Ptr := Sloc (N);
Agg_Type : Entity_Id;
Comp : Node_Id;
Decl : Node_Id;
Typ : constant Entity_Id := Etype (N);
Indices : List_Id := New_List;
Num : Int;
Sub_Agg : Node_Id;
begin
Agg_Type :=
Make_Defining_Identifier (
Loc, New_Internal_Name ('A'));
-- If the aggregate is purely positional, all its subaggregates
-- have the same size. We collect the dimensions from the first
-- subaggregate at each level.
if Positional then
Sub_Agg := N;
for D in 1 .. Number_Dimensions (Typ) loop
Comp := First (Expressions (Sub_Agg));
Sub_Agg := Comp;
Num := 0;
while Present (Comp) loop
Num := Num + 1;
Next (Comp);
end loop;
Append (
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound =>
Make_Integer_Literal (Loc, Num)),
Indices);
end loop;
else
-- We know the aggregate type is unconstrained and the
-- aggregate is not processable by the back end, therefore
-- not necessarily positional. Retrieve the bounds of each
-- dimension as computed earlier.
for D in 1 .. Number_Dimensions (Typ) loop
Append (
Make_Range (Loc,
Low_Bound => Aggr_Low (D),
High_Bound => Aggr_High (D)),
Indices);
end loop;
end if;
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Agg_Type,
Type_Definition =>
Make_Constrained_Array_Definition (Loc,
Discrete_Subtype_Definitions => Indices,
Subtype_Indication =>
New_Occurrence_Of (Component_Type (Typ), Loc)));
Insert_Action (N, Decl);
Analyze (Decl);
Set_Etype (N, Agg_Type);
Set_Is_Itype (Agg_Type);
Freeze_Itype (Agg_Type, N);
end Build_Constrained_Type;
------------------
-- Check_Bounds --
------------------
procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
Aggr_Lo : Node_Id;
Aggr_Hi : Node_Id;
Ind_Lo : Node_Id;
Ind_Hi : Node_Id;
Cond : Node_Id := Empty;
begin
Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
-- Generate the following test:
--
-- [constraint_error when
-- Aggr_Lo <= Aggr_Hi and then
-- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
--
-- As an optimization try to see if some tests are trivially vacuos
-- because we are comparing an expression against itself.
if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
Cond := Empty;
elsif Aggr_Hi = Ind_Hi then
Cond :=
Make_Op_Lt (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Lo),
Right_Opnd => Duplicate_Subexpr (Ind_Lo));
elsif Aggr_Lo = Ind_Lo then
Cond :=
Make_Op_Gt (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
Right_Opnd => Duplicate_Subexpr (Ind_Hi));
else
Cond :=
Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Lt (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Lo),
Right_Opnd => Duplicate_Subexpr (Ind_Lo)),
Right_Opnd =>
Make_Op_Gt (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
end if;
if Present (Cond) then
Cond :=
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Le (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Lo),
Right_Opnd => Duplicate_Subexpr (Aggr_Hi)),
Right_Opnd => Cond);
Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
Insert_Action (N,
Make_Raise_Constraint_Error (Loc, Condition => Cond));
end if;
end Check_Bounds;
----------------------------
-- Check_Same_Aggr_Bounds --
----------------------------
procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
-- The bounds of this specific sub-aggregate.
Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
Aggr_Hi : constant Node_Id := Aggr_High (Dim);
-- The bounds of the aggregate for this dimension
Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
-- The index type for this dimension.
Cond : Node_Id := Empty;
Assoc : Node_Id;
Expr : Node_Id;
begin
-- If index checks are on generate the test
--
-- [constraint_error when
-- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
--
-- As an optimization try to see if some tests are trivially vacuos
-- because we are comparing an expression against itself. Also for
-- the first dimension the test is trivially vacuous because there
-- is just one aggregate for dimension 1.
if Index_Checks_Suppressed (Ind_Typ) then
Cond := Empty;
elsif Dim = 1
or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
then
Cond := Empty;
elsif Aggr_Hi = Sub_Hi then
Cond :=
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Lo),
Right_Opnd => Duplicate_Subexpr (Sub_Lo));
elsif Aggr_Lo = Sub_Lo then
Cond :=
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
Right_Opnd => Duplicate_Subexpr (Sub_Hi));
else
Cond :=
Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Lo),
Right_Opnd => Duplicate_Subexpr (Sub_Lo)),
Right_Opnd =>
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
end if;
if Present (Cond) then
Insert_Action (N,
Make_Raise_Constraint_Error (Loc, Condition => Cond));
end if;
-- Now look inside the sub-aggregate to see if there is more work
if Dim < Aggr_Dimension then
-- Process positional components
if Present (Expressions (Sub_Aggr)) then
Expr := First (Expressions (Sub_Aggr));
while Present (Expr) loop
Check_Same_Aggr_Bounds (Expr, Dim + 1);
Next (Expr);
end loop;
end if;
-- Process component associations
if Present (Component_Associations (Sub_Aggr)) then
Assoc := First (Component_Associations (Sub_Aggr));
while Present (Assoc) loop
Expr := Expression (Assoc);
Check_Same_Aggr_Bounds (Expr, Dim + 1);
Next (Assoc);
end loop;
end if;
end if;
end Check_Same_Aggr_Bounds;
----------------------------
-- Compute_Others_Present --
----------------------------
procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
Assoc : Node_Id;
Expr : Node_Id;
begin
if Present (Component_Associations (Sub_Aggr)) then
Assoc := Last (Component_Associations (Sub_Aggr));
if Nkind (First (Choices (Assoc))) = N_Others_Choice then
Others_Present (Dim) := True;
end if;
end if;
-- Now look inside the sub-aggregate to see if there is more work
if Dim < Aggr_Dimension then
-- Process positional components
if Present (Expressions (Sub_Aggr)) then
Expr := First (Expressions (Sub_Aggr));
while Present (Expr) loop
Compute_Others_Present (Expr, Dim + 1);
Next (Expr);
end loop;
end if;
-- Process component associations
if Present (Component_Associations (Sub_Aggr)) then
Assoc := First (Component_Associations (Sub_Aggr));
while Present (Assoc) loop
Expr := Expression (Assoc);
Compute_Others_Present (Expr, Dim + 1);
Next (Assoc);
end loop;
end if;
end if;
end Compute_Others_Present;
---------------------------
-- Convert_To_Positional --
---------------------------
procedure Convert_To_Positional (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
Ndim : constant Pos := Number_Dimensions (Typ);
Xtyp : constant Entity_Id := Etype (First_Index (Typ));
Blo : constant Node_Id :=
Type_Low_Bound (Etype (First_Index (Base_Type (Typ))));
Lo : constant Node_Id := Type_Low_Bound (Xtyp);
Hi : constant Node_Id := Type_High_Bound (Xtyp);
Lov : Uint;
Hiv : Uint;
Max_Aggr_Size : constant := 500;
-- Maximum size of aggregate produced by converting positional to
-- named notation. This avoids running away with attempts to
-- convert huge aggregates.
Max_Others_Replicate : constant := 5;
-- This constant defines the maximum expansion of an others clause
-- into a list of values. This applies when converting a named
-- aggregate to positional form for processing by the back end.
-- If a given others clause generates more than five values, the
-- aggregate is retained as named, since the loop is more compact.
-- However, this constant is completely overridden if restriction
-- No_Elaboration_Code is active, since in this case, the loop
-- would not be allowed anyway. Similarly No_Implicit_Loops causes
-- this parameter to be ignored.
begin
-- For now, we only handle the one dimensional case and aggregates
-- that are not part of a component_association
if Ndim > 1 or else Nkind (Parent (N)) = N_Aggregate
or else Nkind (Parent (N)) = N_Component_Association
then
return;
end if;
-- If already positional, nothing to do!
if No (Component_Associations (N)) then
return;
end if;
-- 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;
end if;
-- Do not attempt to convert bit packed arrays, since they cannot
-- be handled by the backend in any case.
if Is_Bit_Packed_Array (Typ) then
return;
end if;
-- Do not convert to positional if controlled components are
-- involved since these require special processing
if Has_Controlled_Component (Typ) then
return;
end if;
-- Get bounds and check reasonable size (positive, not too large)
-- Also only handle bounds starting at the base type low bound for
-- now since the compiler isn't able to handle different low bounds
-- yet
Lov := Expr_Value (Lo);
Hiv := Expr_Value (Hi);
if Hiv < Lov
or else (Hiv - Lov > Max_Aggr_Size)
or else not Compile_Time_Known_Value (Blo)
or else (Lov /= Expr_Value (Blo))
then
return;
end if;
-- Bounds must be in integer range (for array Vals below)
if not UI_Is_In_Int_Range (Lov)
or else
not UI_Is_In_Int_Range (Hiv)
then
return;
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 : Node_Id;
Lo, Hi : Node_Id;
begin
if Present (Expressions (N)) then
Elmt := First (Expressions (N));
while Present (Elmt) loop
Vals (Num) := Relocate_Node (Elmt);
Num := Num + 1;
Next (Elmt);
end loop;
end if;
Elmt := First (Component_Associations (N));
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;
if Rep_Count > Max_Others_Replicate
and then not Restrictions (No_Elaboration_Code)
and then not Restrictions (No_Implicit_Loops)
then
return;
end if;
end if;
end loop;
exit Component_Loop;
-- Case of a subtype mark
elsif (Nkind (Choice) = N_Identifier
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;
else
Vals (UI_To_Int (Expr_Value (Choice))) :=
New_Copy_Tree (Expression (Elmt));
goto Continue;
end if;
end if;
-- Range cases merge with Lo,Hi said
if not Compile_Time_Known_Value (Lo)
or else
not Compile_Time_Known_Value (Hi)
then
return;
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));
Analyze_And_Resolve (N, Typ);
end;
end Convert_To_Positional;
-------------------------
-- Has_Address_Clause --
-------------------------
function Has_Address_Clause (D : Node_Id) return Boolean is
Id : Entity_Id := Defining_Identifier (D);
Decl : Node_Id := Next (D);
begin
while Present (Decl) loop
if Nkind (Decl) = N_At_Clause
and then Chars (Identifier (Decl)) = Chars (Id)
then
return True;
elsif Nkind (Decl) = N_Attribute_Definition_Clause
and then Chars (Decl) = Name_Address
and then Chars (Name (Decl)) = Chars (Id)
then
return True;
end if;
Next (Decl);
end loop;
return False;
end Has_Address_Clause;
------------------------
-- In_Place_Assign_OK --
------------------------
function In_Place_Assign_OK return Boolean is
Aggr_In : Node_Id;
Aggr_Lo : Node_Id;
Aggr_Hi : Node_Id;
Obj_In : Node_Id;
Obj_Lo : Node_Id;
Obj_Hi : Node_Id;
function Safe_Aggregate (Aggr : Node_Id) return Boolean;
-- Check recursively that each component of a (sub)aggregate does
-- not depend on the variable being assigned to.
function Safe_Component (Expr : Node_Id) return Boolean;
-- Verify that an expression cannot depend on the variable being
-- assigned to. Room for improvement here (but less than before).
--------------------
-- Safe_Aggregate --
--------------------
function Safe_Aggregate (Aggr : Node_Id) return Boolean is
Expr : Node_Id;
begin
if Present (Expressions (Aggr)) then
Expr := First (Expressions (Aggr));
while Present (Expr) loop
if Nkind (Expr) = N_Aggregate then
if not Safe_Aggregate (Expr) then
return False;
end if;
elsif not Safe_Component (Expr) then
return False;
end if;
Next (Expr);
end loop;
end if;
if Present (Component_Associations (Aggr)) then
Expr := First (Component_Associations (Aggr));
while Present (Expr) loop
if Nkind (Expression (Expr)) = N_Aggregate then
if not Safe_Aggregate (Expression (Expr)) then
return False;
end if;
elsif not Safe_Component (Expression (Expr)) then
return False;
end if;
Next (Expr);
end loop;
end if;
return True;
end Safe_Aggregate;
--------------------
-- Safe_Component --
--------------------
function Safe_Component (Expr : Node_Id) return Boolean is
Comp : Node_Id := Expr;
function Check_Component (Comp : Node_Id) return Boolean;
-- Do the recursive traversal, after copy.
function Check_Component (Comp : Node_Id) return Boolean is
begin
if Is_Overloaded (Comp) then
return False;
end if;
return Compile_Time_Known_Value (Comp)
or else (Is_Entity_Name (Comp)
and then Present (Entity (Comp))
and then No (Renamed_Object (Entity (Comp))))
or else (Nkind (Comp) = N_Attribute_Reference
and then Check_Component (Prefix (Comp)))
or else (Nkind (Comp) in N_Binary_Op
and then Check_Component (Left_Opnd (Comp))
and then Check_Component (Right_Opnd (Comp)))
or else (Nkind (Comp) in N_Unary_Op
and then Check_Component (Right_Opnd (Comp)))
or else (Nkind (Comp) = N_Selected_Component
and then Check_Component (Prefix (Comp)));
end Check_Component;
-- Start of processing for Safe_Component
begin
-- If the component appears in an association that may
-- correspond to more than one element, it is not analyzed
-- before the expansion into assignments, to avoid side effects.
-- We analyze, but do not resolve the copy, to obtain sufficient
-- entity information for the checks that follow. If component is
-- overloaded we assume an unsafe function call.
if not Analyzed (Comp) then
if Is_Overloaded (Expr) then
return False;
end if;
Comp := New_Copy_Tree (Expr);
Analyze (Comp);
end if;
return Check_Component (Comp);
end Safe_Component;
-- Start of processing for In_Place_Assign_OK
begin
if Present (Component_Associations (N)) then
-- On assignment, sliding can take place, so we cannot do the
-- assignment in place unless the bounds of the aggregate are
-- statically equal to those of the target.
-- If the aggregate is given by an others choice, the bounds
-- are derived from the left-hand side, and the assignment is
-- safe if the expression is.
if No (Expressions (N))
and then Nkind
(First (Choices (First (Component_Associations (N)))))
= N_Others_Choice
then
return
Safe_Component
(Expression (First (Component_Associations (N))));
end if;
Aggr_In := First_Index (Etype (N));
Obj_In := First_Index (Etype (Name (Parent (N))));
while Present (Aggr_In) loop
Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
if not Compile_Time_Known_Value (Aggr_Lo)
or else not Compile_Time_Known_Value (Aggr_Hi)
or else not Compile_Time_Known_Value (Obj_Lo)
or else not Compile_Time_Known_Value (Obj_Hi)
or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
then
return False;
end if;
Next_Index (Aggr_In);
Next_Index (Obj_In);
end loop;
end if;
-- Now check the component values themselves.
return Safe_Aggregate (N);
end In_Place_Assign_OK;
------------------
-- Others_Check --
------------------
procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
Aggr_Hi : constant Node_Id := Aggr_High (Dim);
-- The bounds of the aggregate for this dimension.
Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
-- The index type for this dimension.
Need_To_Check : Boolean := False;
Choices_Lo : Node_Id := Empty;
Choices_Hi : Node_Id := Empty;
-- The lowest and highest discrete choices for a named sub-aggregate
Nb_Choices : Int := -1;
-- The number of discrete non-others choices in this sub-aggregate
Nb_Elements : Uint := Uint_0;
-- The number of elements in a positional aggregate
Cond : Node_Id := Empty;
Assoc : Node_Id;
Choice : Node_Id;
Expr : Node_Id;
begin
-- Check if we have an others choice. If we do make sure that this
-- sub-aggregate contains at least one element in addition to the
-- others choice.
if Range_Checks_Suppressed (Ind_Typ) then
Need_To_Check := False;
elsif Present (Expressions (Sub_Aggr))
and then Present (Component_Associations (Sub_Aggr))
then
Need_To_Check := True;
elsif Present (Component_Associations (Sub_Aggr)) then
Assoc := Last (Component_Associations (Sub_Aggr));
if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
Need_To_Check := False;
else
-- Count the number of discrete choices. Start with -1
-- because the others choice does not count.
Nb_Choices := -1;
Assoc := First (Component_Associations (Sub_Aggr));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
while Present (Choice) loop
Nb_Choices := Nb_Choices + 1;
Next (Choice);
end loop;
Next (Assoc);
end loop;
-- If there is only an others choice nothing to do
Need_To_Check := (Nb_Choices > 0);
end if;
else
Need_To_Check := False;
end if;
-- If we are dealing with a positional sub-aggregate with an
-- others choice, compute the number or positional elements.
if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
Expr := First (Expressions (Sub_Aggr));
Nb_Elements := Uint_0;
while Present (Expr) loop
Nb_Elements := Nb_Elements + 1;
Next (Expr);
end loop;
-- If the aggregate contains discrete choices and an others choice
-- compute the smallest and largest discrete choice values.
elsif Need_To_Check then
Compute_Choices_Lo_And_Choices_Hi : declare
Table : Case_Table_Type (1 .. Nb_Choices);
-- Used to sort all the different choice values
I : Pos := 1;
Low : Node_Id;
High : Node_Id;
begin
Assoc := First (Component_Associations (Sub_Aggr));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
while Present (Choice) loop
if Nkind (Choice) = N_Others_Choice then
exit;
end if;
Get_Index_Bounds (Choice, Low, High);
Table (I).Choice_Lo := Low;
Table (I).Choice_Hi := High;
I := I + 1;
Next (Choice);
end loop;
Next (Assoc);
end loop;
-- Sort the discrete choices
Sort_Case_Table (Table);
Choices_Lo := Table (1).Choice_Lo;
Choices_Hi := Table (Nb_Choices).Choice_Hi;
end Compute_Choices_Lo_And_Choices_Hi;
end if;
-- If no others choice in this sub-aggregate, or the aggregate
-- comprises only an others choice, nothing to do.
if not Need_To_Check then
Cond := Empty;
-- If we are dealing with an aggregate containing an others
-- choice and positional components, we generate the following test:
--
-- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
-- Ind_Typ'Pos (Aggr_Hi)
-- then
-- raise Constraint_Error;
-- end if;
elsif Nb_Elements > Uint_0 then
Cond :=
Make_Op_Gt (Loc,
Left_Opnd =>
Make_Op_Add (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ind_Typ, Loc),
Attribute_Name => Name_Pos,
Expressions =>
New_List (Duplicate_Subexpr (Aggr_Lo))),
Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ind_Typ, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (Duplicate_Subexpr (Aggr_Hi))));
-- If we are dealing with an aggregate containing an others
-- choice and discrete choices we generate the following test:
--
-- [constraint_error when
-- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
else
Cond :=
Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Lt (Loc,
Left_Opnd => Duplicate_Subexpr (Choices_Lo),
Right_Opnd => Duplicate_Subexpr (Aggr_Lo)),
Right_Opnd =>
Make_Op_Gt (Loc,
Left_Opnd => Duplicate_Subexpr (Choices_Hi),
Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
end if;
if Present (Cond) then
Insert_Action (N,
Make_Raise_Constraint_Error (Loc, Condition => Cond));
end if;
-- Now look inside the sub-aggregate to see if there is more work
if Dim < Aggr_Dimension then
-- Process positional components
if Present (Expressions (Sub_Aggr)) then
Expr := First (Expressions (Sub_Aggr));
while Present (Expr) loop
Others_Check (Expr, Dim + 1);
Next (Expr);
end loop;
end if;
-- Process component associations
if Present (Component_Associations (Sub_Aggr)) then
Assoc := First (Component_Associations (Sub_Aggr));
while Present (Assoc) loop
Expr := Expression (Assoc);
Others_Check (Expr, Dim + 1);
Next (Assoc);
end loop;
end if;
end if;
end Others_Check;
-- Remaining Expand_Array_Aggregate variables
Tmp : Entity_Id;
-- Holds the temporary aggregate value.
Tmp_Decl : Node_Id;
-- Holds the declaration of Tmp.
Aggr_Code : List_Id;
Parent_Node : Node_Id;
Parent_Kind : Node_Kind;
-- Start of processing for Expand_Array_Aggregate
begin
-- Do not touch the special aggregates of attributes used for Asm calls
if Is_RTE (Ctyp, RE_Asm_Input_Operand)
or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
then
return;
end if;
-- If during semantic analysis it has been determined that aggregate N
-- will raise Constraint_Error at run-time, then the aggregate node
-- has been replaced with an N_Raise_Constraint_Error node and we
-- should never get here.
pragma Assert (not Raises_Constraint_Error (N));
-- STEP 1: Check (a)
Index_Compatibility_Check : declare
Aggr_Index_Range : Node_Id := First_Index (Typ);
-- The current aggregate index range
Index_Constraint : Node_Id := First_Index (Etype (Typ));
-- The corresponding index constraint against which we have to
-- check the above aggregate index range.
begin
Compute_Others_Present (N, 1);
for J in 1 .. Aggr_Dimension loop
-- There is no need to emit a check if an others choice is
-- present for this array aggregate dimension since in this
-- case one of N's sub-aggregates has taken its bounds from the
-- context and these bounds must have been checked already. In
-- addition all sub-aggregates corresponding to the same
-- dimension must all have the same bounds (checked in (c) below).
if not Range_Checks_Suppressed (Etype (Index_Constraint))
and then not Others_Present (J)
then
-- We don't use Checks.Apply_Range_Check here because it
-- emits a spurious check. Namely it checks that the range
-- defined by the aggregate bounds is non empty. But we know
-- this already if we get here.
Check_Bounds (Aggr_Index_Range, Index_Constraint);
end if;
-- Save the low and high bounds of the aggregate index as well
-- as the index type for later use in checks (b) and (c) below.
Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
Aggr_High (J) := High_Bound (Aggr_Index_Range);
Aggr_Index_Typ (J) := Etype (Index_Constraint);
Next_Index (Aggr_Index_Range);
Next_Index (Index_Constraint);
end loop;
end Index_Compatibility_Check;
-- STEP 1: Check (b)
Others_Check (N, 1);
-- STEP 1: Check (c)
if Aggr_Dimension > 1 then
Check_Same_Aggr_Bounds (N, 1);
end if;
-- STEP 2.
-- First try to convert to positional form. If the result is not
-- an aggregate any more, then we are done with the analysis (it
-- it could be a string literal or an identifier for a temporary
-- variable following this call). If result is an analyzed aggregate
-- the transformation was also successful and we are done as well.
Convert_To_Positional (N);
if Nkind (N) /= N_Aggregate then
return;
elsif Analyzed (N)
and then N /= Original_Node (N)
then
return;
end if;
if Backend_Processing_Possible (N) then
-- If the aggregate is static but the constraints are not, build
-- a static subtype for the aggregate, so that Gigi can place it
-- in static memory. Perform an unchecked_conversion to the non-
-- static type imposed by the context.
declare
Itype : constant Entity_Id := Etype (N);
Index : Node_Id;
Needs_Type : Boolean := False;
begin
Index := First_Index (Itype);
while Present (Index) loop
if not Is_Static_Subtype (Etype (Index)) then
Needs_Type := True;
exit;
else
Next_Index (Index);
end if;
end loop;
if Needs_Type then
Build_Constrained_Type (Positional => True);
Rewrite (N, Unchecked_Convert_To (Itype, N));
Analyze (N);
end if;
end;
return;
end if;
-- Delay expansion for nested aggregates it will be taken care of
-- when the parent aggregate is expanded
Parent_Node := Parent (N);
Parent_Kind := Nkind (Parent_Node);
if Parent_Kind = N_Qualified_Expression then
Parent_Node := Parent (Parent_Node);
Parent_Kind := Nkind (Parent_Node);
end if;
if Parent_Kind = N_Aggregate
or else Parent_Kind = N_Extension_Aggregate
or else Parent_Kind = N_Component_Association
or else (Parent_Kind = N_Object_Declaration
and then Controlled_Type (Typ))
or else (Parent_Kind = N_Assignment_Statement
and then Inside_Init_Proc)
then
Set_Expansion_Delayed (N);
return;
end if;
-- STEP 3.
-- Look if in place aggregate expansion is possible
-- For object declarations we build the aggregate in place, unless
-- the array is bit-packed or the component is controlled.
-- For assignments we do the assignment in place if all the component
-- associations have compile-time known values. For other cases we
-- create a temporary. The analysis for safety of on-line assignment
-- is delicate, i.e. we don't know how to do it fully yet ???
if Requires_Transient_Scope (Typ) then
Establish_Transient_Scope
(N, Sec_Stack => Has_Controlled_Component (Typ));
end if;
Maybe_In_Place_OK :=
Comes_From_Source (N)
and then Nkind (Parent (N)) = N_Assignment_Statement
and then not Is_Bit_Packed_Array (Typ)
and then not Has_Controlled_Component (Typ)
and then In_Place_Assign_OK;
if Comes_From_Source (Parent (N))
and then Nkind (Parent (N)) = N_Object_Declaration
and then N = Expression (Parent (N))
and then not Is_Bit_Packed_Array (Typ)
and then not Has_Controlled_Component (Typ)
and then not Has_Address_Clause (Parent (N))
then
Tmp := Defining_Identifier (Parent (N));
Set_No_Initialization (Parent (N));
Set_Expression (Parent (N), Empty);
-- Set the type of the entity, for use in the analysis of the
-- subsequent indexed assignments. If the nominal type is not
-- constrained, build a subtype from the known bounds of the
-- aggregate. If the declaration has a subtype mark, use it,
-- otherwise use the itype of the aggregate.
if not Is_Constrained (Typ) then
Build_Constrained_Type (Positional => False);
elsif Is_Entity_Name (Object_Definition (Parent (N)))
and then Is_Constrained (Entity (Object_Definition (Parent (N))))
then
Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
else
Set_Size_Known_At_Compile_Time (Typ, False);
Set_Etype (Tmp, Typ);
end if;
elsif Maybe_In_Place_OK
and then Is_Entity_Name (Name (Parent (N)))
then
Tmp := Entity (Name (Parent (N)));
if Etype (Tmp) /= Etype (N) then
Apply_Length_Check (N, Etype (Tmp));
end if;
elsif Maybe_In_Place_OK
and then Nkind (Name (Parent (N))) = N_Slice
and then Safe_Slice_Assignment (N, Typ)
then
-- Safe_Slice_Assignment rewrites assignment as a loop.
return;
else
Tmp := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Tmp_Decl :=
Make_Object_Declaration
(Loc,
Defining_Identifier => Tmp,
Object_Definition => New_Occurrence_Of (Typ, Loc));
Set_No_Initialization (Tmp_Decl, True);
-- If we are within a loop, the temporary will be pushed on the
-- stack at each iteration. If the aggregate is the expression for
-- an allocator, it will be immediately copied to the heap and can
-- be reclaimed at once. We create a transient scope around the
-- aggregate for this purpose.
if Ekind (Current_Scope) = E_Loop
and then Nkind (Parent (Parent (N))) = N_Allocator
then
Establish_Transient_Scope (N, False);
end if;
Insert_Action (N, Tmp_Decl);
end if;
-- Construct and insert the aggregate code. We can safely suppress
-- index checks because this code is guaranteed not to raise CE
-- on index checks. However we should *not* suppress all checks.
Aggr_Code :=
Build_Array_Aggr_Code (N,
Index => First_Index (Typ),
Into => New_Reference_To (Tmp, Loc),
Scalar_Comp => Is_Scalar_Type (Ctyp));
if Comes_From_Source (Tmp) then
Insert_Actions_After (Parent (N), Aggr_Code);
else
Insert_Actions (N, Aggr_Code);
end if;
if Nkind (Parent (N)) = N_Assignment_Statement
and then Is_Entity_Name (Name (Parent (N)))
and then Tmp = Entity (Name (Parent (N)))
then
Rewrite (Parent (N), Make_Null_Statement (Loc));
Analyze (N);
elsif Nkind (Parent (N)) /= N_Object_Declaration
or else Tmp /= Defining_Identifier (Parent (N))
then
Rewrite (N, New_Occurrence_Of (Tmp, Loc));
Analyze_And_Resolve (N, Typ);
end if;
end Expand_Array_Aggregate;
------------------------
-- Expand_N_Aggregate --
------------------------
procedure Expand_N_Aggregate (N : Node_Id) is
begin
if Is_Record_Type (Etype (N)) then
Expand_Record_Aggregate (N);
else
Expand_Array_Aggregate (N);
end if;
end Expand_N_Aggregate;
----------------------------------
-- Expand_N_Extension_Aggregate --
----------------------------------
-- If the ancestor part is an expression, add a component association for
-- the parent field. If the type of the ancestor part is not the direct
-- parent of the expected type, build recursively the needed ancestors.
-- If the ancestor part is a subtype_mark, replace aggregate with a decla-
-- ration for a temporary of the expected type, followed by individual
-- assignments to the given components.
procedure Expand_N_Extension_Aggregate (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
A : constant Node_Id := Ancestor_Part (N);
Typ : constant Entity_Id := Etype (N);
begin
-- If the ancestor is a subtype mark, an init_proc must be called
-- on the resulting object which thus has to be materialized in
-- the front-end
if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
Convert_To_Assignments (N, Typ);
-- The extension aggregate is transformed into a record aggregate
-- of the following form (c1 and c2 are inherited components)
-- (Exp with c3 => a, c4 => b)
-- ==> (c1 => Exp.c1, c2 => Exp.c2, c1 => a, c2 => b)
else
Set_Etype (N, Typ);
-- No tag is needed in the case of Java_VM
if Java_VM then
Expand_Record_Aggregate (N,
Parent_Expr => A);
else
Expand_Record_Aggregate (N,
Orig_Tag => New_Occurrence_Of (Access_Disp_Table (Typ), Loc),
Parent_Expr => A);
end if;
end if;
end Expand_N_Extension_Aggregate;
-----------------------------
-- Expand_Record_Aggregate --
-----------------------------
procedure Expand_Record_Aggregate
(N : Node_Id;
Orig_Tag : Node_Id := Empty;
Parent_Expr : Node_Id := Empty)
is
Loc : constant Source_Ptr := Sloc (N);
Comps : constant List_Id := Component_Associations (N);
Typ : constant Entity_Id := Etype (N);
Base_Typ : constant Entity_Id := Base_Type (Typ);
function Has_Delayed_Nested_Aggregate_Or_Tagged_Comps return Boolean;
-- Checks the presence of a nested aggregate which needs Late_Expansion
-- or the presence of tagged components which may need tag adjustment.
--------------------------------------------------
-- Has_Delayed_Nested_Aggregate_Or_Tagged_Comps --
--------------------------------------------------
function Has_Delayed_Nested_Aggregate_Or_Tagged_Comps return Boolean is
C : Node_Id;
Expr_Q : Node_Id;
begin
if No (Comps) then
return False;
end if;
C := First (Comps);
while Present (C) loop
if Nkind (Expression (C)) = N_Qualified_Expression then
Expr_Q := Expression (Expression (C));
else
Expr_Q := Expression (C);
end if;
-- Return true if the aggregate has any associations for
-- tagged components that may require tag adjustment.
-- These are cases where the source expression may have
-- a tag that could differ from the component tag (e.g.,
-- can occur for type conversions and formal parameters).
-- (Tag adjustment is not needed if Java_VM because object
-- tags are implicit in the JVM.)
if Is_Tagged_Type (Etype (Expr_Q))
and then (Nkind (Expr_Q) = N_Type_Conversion
or else (Is_Entity_Name (Expr_Q)
and then Ekind (Entity (Expr_Q)) in Formal_Kind))
and then not Java_VM
then
return True;
end if;
if Is_Delayed_Aggregate (Expr_Q) then
return True;
end if;
Next (C);
end loop;
return False;
end Has_Delayed_Nested_Aggregate_Or_Tagged_Comps;
-- Remaining Expand_Record_Aggregate variables
Tag_Value : Node_Id;
Comp : Entity_Id;
New_Comp : Node_Id;
-- Start of processing for Expand_Record_Aggregate
begin
-- Gigi doesn't handle properly temporaries of variable size
-- so we generate it in the front-end
if not Size_Known_At_Compile_Time (Typ) then
Convert_To_Assignments (N, Typ);
-- Temporaries for controlled aggregates need to be attached to a
-- final chain in order to be properly finalized, so it has to
-- be created in the front-end
elsif Is_Controlled (Typ)
or else Has_Controlled_Component (Base_Type (Typ))
then
Convert_To_Assignments (N, Typ);
elsif Has_Delayed_Nested_Aggregate_Or_Tagged_Comps then
Convert_To_Assignments (N, Typ);
-- If an ancestor is private, some components are not inherited and
-- we cannot expand into a record aggregate
elsif Has_Private_Ancestor (Typ) then
Convert_To_Assignments (N, Typ);
-- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
-- is not able to handle the aggregate for Late_Request.
elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
Convert_To_Assignments (N, Typ);
-- In all other cases we generate a proper aggregate that
-- can be handled by gigi.
else
if not Has_Discriminants (Typ) then
-- This bizarre if/elsif is to avoid a compiler crash ???
null;
elsif Is_Derived_Type (Typ) then
-- Non-girder discriminants are replaced with girder discriminants
declare
First_Comp : Node_Id;
Discriminant : Entity_Id;
begin
-- Remove all the discriminants
First_Comp := First (Component_Associations (N));
while Present (First_Comp) loop
Comp := First_Comp;
Next (First_Comp);
if Ekind (Entity (First (Choices (Comp)))) =
E_Discriminant
then
Remove (Comp);
end if;
end loop;
-- Insert girder discriminant associations
-- in the correct order
First_Comp := Empty;
Discriminant := First_Girder_Discriminant (Typ);
while Present (Discriminant) loop
New_Comp :=
Make_Component_Association (Loc,
Choices =>
New_List (New_Occurrence_Of (Discriminant, Loc)),
Expression =>
New_Copy_Tree (
Get_Discriminant_Value (
Discriminant,
Typ,
Discriminant_Constraint (Typ))));
if No (First_Comp) then
Prepend_To (Component_Associations (N), New_Comp);
else
Insert_After (First_Comp, New_Comp);
end if;
First_Comp := New_Comp;
Next_Girder_Discriminant (Discriminant);
end loop;
end;
end if;
if Is_Tagged_Type (Typ) then
-- The tagged case, _parent and _tag component must be created.
-- Reset null_present unconditionally. tagged records always have
-- at least one field (the tag or the parent)
Set_Null_Record_Present (N, False);
-- When the current aggregate comes from the expansion of an
-- extension aggregate, the parent expr is replaced by an
-- aggregate formed by selected components of this expr
if Present (Parent_Expr)
and then Is_Empty_List (Comps)
then
Comp := First_Entity (Typ);
while Present (Comp) loop
-- Skip all entities that aren't discriminants or components
if Ekind (Comp) /= E_Discriminant
and then Ekind (Comp) /= E_Component
then
null;
-- Skip all expander-generated components
elsif
not Comes_From_Source (Original_Record_Component (Comp))
then
null;
else
New_Comp :=
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Typ,
Duplicate_Subexpr (Parent_Expr, True)),
Selector_Name => New_Occurrence_Of (Comp, Loc));
Append_To (Comps,
Make_Component_Association (Loc,
Choices =>
New_List (New_Occurrence_Of (Comp, Loc)),
Expression =>
New_Comp));
Analyze_And_Resolve (New_Comp, Etype (Comp));
end if;
Next_Entity (Comp);
end loop;
end if;
-- Compute the value for the Tag now, if the type is a root it
-- will be included in the aggregate right away, otherwise it will
-- be propagated to the parent aggregate
if Present (Orig_Tag) then
Tag_Value := Orig_Tag;
elsif Java_VM then
Tag_Value := Empty;
else
Tag_Value := New_Occurrence_Of (Access_Disp_Table (Typ), Loc);
end if;
-- For a derived type, an aggregate for the parent is formed with
-- all the inherited components.
if Is_Derived_Type (Typ) then
declare
First_Comp : Node_Id;
Parent_Comps : List_Id;
Parent_Aggr : Node_Id;
Parent_Name : Node_Id;
begin
-- Remove the inherited component association from the
-- aggregate and store them in the parent aggregate
First_Comp := First (Component_Associations (N));
Parent_Comps := New_List;
while Present (First_Comp)
and then Scope (Original_Record_Component (
Entity (First (Choices (First_Comp))))) /= Base_Typ
loop
Comp := First_Comp;
Next (First_Comp);
Remove (Comp);
Append (Comp, Parent_Comps);
end loop;
Parent_Aggr := Make_Aggregate (Loc,
Component_Associations => Parent_Comps);
Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
-- Find the _parent component
Comp := First_Component (Typ);
while Chars (Comp) /= Name_uParent loop
Comp := Next_Component (Comp);
end loop;
Parent_Name := New_Occurrence_Of (Comp, Loc);
-- Insert the parent aggregate
Prepend_To (Component_Associations (N),
Make_Component_Association (Loc,
Choices => New_List (Parent_Name),
Expression => Parent_Aggr));
-- Expand recursively the parent propagating the right Tag
Expand_Record_Aggregate (
Parent_Aggr, Tag_Value, Parent_Expr);
end;
-- For a root type, the tag component is added (unless compiling
-- for the Java VM, where tags are implicit).
elsif not Java_VM then
declare
Tag_Name : constant Node_Id :=
New_Occurrence_Of (Tag_Component (Typ), Loc);
Typ_Tag : constant Entity_Id := RTE (RE_Tag);
Conv_Node : constant Node_Id :=
Unchecked_Convert_To (Typ_Tag, Tag_Value);
begin
Set_Etype (Conv_Node, Typ_Tag);
Prepend_To (Component_Associations (N),
Make_Component_Association (Loc,
Choices => New_List (Tag_Name),
Expression => Conv_Node));
end;
end if;
end if;
end if;
end Expand_Record_Aggregate;
--------------------------
-- Is_Delayed_Aggregate --
--------------------------
function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
Node : Node_Id := N;
Kind : Node_Kind := Nkind (Node);
begin
if Kind = N_Qualified_Expression then
Node := Expression (Node);
Kind := Nkind (Node);
end if;
if Kind /= N_Aggregate and then Kind /= N_Extension_Aggregate then
return False;
else
return Expansion_Delayed (Node);
end if;
end Is_Delayed_Aggregate;
--------------------
-- Late_Expansion --
--------------------
function Late_Expansion
(N : Node_Id;
Typ : Entity_Id;
Target : Node_Id;
Flist : Node_Id := Empty;
Obj : Entity_Id := Empty)
return List_Id is
begin
if Is_Record_Type (Etype (N)) then
return Build_Record_Aggr_Code (N, Typ, Target, Flist, Obj);
else
return
Build_Array_Aggr_Code
(N,
First_Index (Typ),
Target,
Is_Scalar_Type (Component_Type (Typ)),
No_List,
Flist);
end if;
end Late_Expansion;
----------------------------------
-- Make_OK_Assignment_Statement --
----------------------------------
function Make_OK_Assignment_Statement
(Sloc : Source_Ptr;
Name : Node_Id;
Expression : Node_Id)
return Node_Id
is
begin
Set_Assignment_OK (Name);
return Make_Assignment_Statement (Sloc, Name, Expression);
end Make_OK_Assignment_Statement;
-----------------------
-- Number_Of_Choices --
-----------------------
function Number_Of_Choices (N : Node_Id) return Nat is
Assoc : Node_Id;
Choice : Node_Id;
Nb_Choices : Nat := 0;
begin
if Present (Expressions (N)) then
return 0;
end if;
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
while Present (Choice) loop
if Nkind (Choice) /= N_Others_Choice then
Nb_Choices := Nb_Choices + 1;
end if;
Next (Choice);
end loop;
Next (Assoc);
end loop;
return Nb_Choices;
end Number_Of_Choices;
---------------------------
-- Safe_Slice_Assignment --
---------------------------
function Safe_Slice_Assignment
(N : Node_Id;
Typ : Entity_Id)
return Boolean
is
Loc : constant Source_Ptr := Sloc (Parent (N));
Pref : constant Node_Id := Prefix (Name (Parent (N)));
Range_Node : constant Node_Id := Discrete_Range (Name (Parent (N)));
Expr : Node_Id;
L_I : Entity_Id;
L_Iter : Node_Id;
L_Body : Node_Id;
Stat : Node_Id;
begin
-- Generate: For J in Range loop Pref (I) := Expr; end loop;
if Comes_From_Source (N)
and then No (Expressions (N))
and then Nkind (First (Choices (First (Component_Associations (N)))))
= N_Others_Choice
then
Expr :=
Expression (First (Component_Associations (N)));
L_I := Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
L_Iter :=
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification
(Loc,
Defining_Identifier => L_I,
Discrete_Subtype_Definition => Relocate_Node (Range_Node)));
L_Body :=
Make_Assignment_Statement (Loc,
Name =>
Make_Indexed_Component (Loc,
Prefix => Relocate_Node (Pref),
Expressions => New_List (New_Occurrence_Of (L_I, Loc))),
Expression => Relocate_Node (Expr));
-- Construct the final loop
Stat :=
Make_Implicit_Loop_Statement
(Node => Parent (N),
Identifier => Empty,
Iteration_Scheme => L_Iter,
Statements => New_List (L_Body));
Rewrite (Parent (N), Stat);
Analyze (Parent (N));
return True;
else
return False;
end if;
end Safe_Slice_Assignment;
---------------------
-- Sort_Case_Table --
---------------------
procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
L : Int := Case_Table'First;
U : Int := Case_Table'Last;
K : Int;
J : Int;
T : Case_Bounds;
begin
K := L;
while K /= U loop
T := Case_Table (K + 1);
J := K + 1;
while J /= L
and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
Expr_Value (T.Choice_Lo)
loop
Case_Table (J) := Case_Table (J - 1);
J := J - 1;
end loop;
Case_Table (J) := T;
K := K + 1;
end loop;
end Sort_Case_Table;
end Exp_Aggr;