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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ S P A R K --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Exp_Ch5; use Exp_Ch5;
with Exp_Dbug; use Exp_Dbug;
with Exp_Util; use Exp_Util;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Rtsfind; use Rtsfind;
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_SPARK is
-----------------------
-- Local Subprograms --
-----------------------
procedure Expand_SPARK_Attribute_Reference (N : Node_Id);
-- Replace occurrences of System'To_Address by calls to
-- System.Storage_Elements.To_Address
procedure Expand_SPARK_N_Object_Renaming_Declaration (N : Node_Id);
-- Perform name evaluation for a renamed object
------------------
-- Expand_SPARK --
------------------
procedure Expand_SPARK (N : Node_Id) is
begin
case Nkind (N) is
-- Qualification of entity names in formal verification mode
-- is limited to the addition of a suffix for homonyms (see
-- Exp_Dbug.Qualify_Entity_Name). We used to qualify entity names
-- as full expansion does, but this was removed as this prevents the
-- verification back-end from using a short name for debugging and
-- user interaction. The verification back-end already takes care
-- of qualifying names when needed.
when N_Block_Statement
| N_Entry_Declaration
| N_Package_Body
| N_Package_Declaration
| N_Protected_Type_Declaration
| N_Subprogram_Body
| N_Task_Type_Declaration
=>
Qualify_Entity_Names (N);
when N_Expanded_Name
| N_Identifier
=>
Expand_SPARK_Potential_Renaming (N);
when N_Object_Renaming_Declaration =>
Expand_SPARK_N_Object_Renaming_Declaration (N);
-- Replace occurrences of System'To_Address by calls to
-- System.Storage_Elements.To_Address
when N_Attribute_Reference =>
Expand_SPARK_Attribute_Reference (N);
-- Loop iterations over arrays need to be expanded, to avoid getting
-- two names referring to the same object in memory (the array and
-- the iterator) in GNATprove, especially since both can be written
-- (thus possibly leading to interferences due to aliasing). No such
-- problem arises with quantified expressions over arrays, which are
-- dealt with specially in GNATprove.
when N_Loop_Statement =>
declare
Scheme : constant Node_Id := Iteration_Scheme (N);
begin
if Present (Scheme)
and then Present (Iterator_Specification (Scheme))
and then
Is_Iterator_Over_Array (Iterator_Specification (Scheme))
then
Expand_Iterator_Loop_Over_Array (N);
end if;
end;
-- In SPARK mode, no other constructs require expansion
when others =>
null;
end case;
end Expand_SPARK;
--------------------------------------
-- Expand_SPARK_Attribute_Reference --
--------------------------------------
procedure Expand_SPARK_Attribute_Reference (N : Node_Id) is
Aname : constant Name_Id := Attribute_Name (N);
Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Expr : Node_Id;
begin
if Attr_Id = Attribute_To_Address then
-- Extract and convert argument to expected type for call
Expr :=
Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (RTE (RE_Integer_Address), Loc),
Expression => Relocate_Node (First (Expressions (N))));
-- Replace attribute reference with call
Rewrite (N,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_To_Address), Loc),
Parameter_Associations => New_List (Expr)));
Analyze_And_Resolve (N, Typ);
-- For attributes which return Universal_Integer, introduce a conversion
-- to the expected type with the appropriate check flags set.
elsif Attr_Id = Attribute_Alignment
or else Attr_Id = Attribute_Bit
or else Attr_Id = Attribute_Bit_Position
or else Attr_Id = Attribute_Descriptor_Size
or else Attr_Id = Attribute_First_Bit
or else Attr_Id = Attribute_Last_Bit
or else Attr_Id = Attribute_Length
or else Attr_Id = Attribute_Max_Size_In_Storage_Elements
or else Attr_Id = Attribute_Pos
or else Attr_Id = Attribute_Position
or else Attr_Id = Attribute_Range_Length
or else Attr_Id = Attribute_Object_Size
or else Attr_Id = Attribute_Size
or else Attr_Id = Attribute_Value_Size
or else Attr_Id = Attribute_VADS_Size
or else Attr_Id = Attribute_Aft
or else Attr_Id = Attribute_Max_Alignment_For_Allocation
then
-- If the expected type is Long_Long_Integer, there will be no check
-- flag as the compiler assumes attributes always fit in this type.
-- Since in SPARK_Mode we do not take Storage_Error into account, we
-- cannot make this assumption and need to produce a check.
-- ??? It should be enough to add this check for attributes 'Length
-- and 'Range_Length when the type is as big as Long_Long_Integer.
declare
Typ : Entity_Id := Empty;
begin
if Attr_Id = Attribute_Range_Length then
Typ := Etype (Prefix (N));
elsif Attr_Id = Attribute_Length then
Typ := Etype (Prefix (N));
declare
Indx : Node_Id;
J : Int;
begin
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
end if;
if No (Expressions (N)) then
J := 1;
else
J := UI_To_Int (Expr_Value (First (Expressions (N))));
end if;
Indx := First_Index (Typ);
while J > 1 loop
Next_Index (Indx);
J := J - 1;
end loop;
Typ := Etype (Indx);
end;
end if;
Apply_Universal_Integer_Attribute_Checks (N);
if Present (Typ)
and then RM_Size (Typ) = RM_Size (Standard_Long_Long_Integer)
then
Set_Do_Overflow_Check (N);
end if;
end;
end if;
end Expand_SPARK_Attribute_Reference;
------------------------------------------------
-- Expand_SPARK_N_Object_Renaming_Declaration --
------------------------------------------------
procedure Expand_SPARK_N_Object_Renaming_Declaration (N : Node_Id) is
begin
-- Unconditionally remove all side effects from the name
Evaluate_Name (Name (N));
end Expand_SPARK_N_Object_Renaming_Declaration;
-------------------------------------
-- Expand_SPARK_Potential_Renaming --
-------------------------------------
procedure Expand_SPARK_Potential_Renaming (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ren_Id : constant Entity_Id := Entity (N);
Typ : constant Entity_Id := Etype (N);
Obj_Id : Node_Id;
begin
-- Replace a reference to a renaming with the actual renamed object
if Ekind (Ren_Id) in Object_Kind then
Obj_Id := Renamed_Object (Ren_Id);
if Present (Obj_Id) then
-- The renamed object is an entity when instantiating generics
-- or inlining bodies. In this case the renaming is part of the
-- mapping "prologue" which links actuals to formals.
if Nkind (Obj_Id) in N_Entity then
Rewrite (N, New_Occurrence_Of (Obj_Id, Loc));
-- Otherwise the renamed object denotes a name
else
Rewrite (N, New_Copy_Tree (Obj_Id, New_Sloc => Loc));
Reset_Analyzed_Flags (N);
end if;
Analyze_And_Resolve (N, Typ);
end if;
end if;
end Expand_SPARK_Potential_Renaming;
end Exp_SPARK;
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