+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- I N T E R F A C E S . C . P O I N T E R S --
--- --
--- B o d y --
--- --
--- $Revision: 1.1.16.1 $
--- --
--- 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. --
--- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-with Interfaces.C.Strings; use Interfaces.C.Strings;
-with System; use System;
-
-with Unchecked_Conversion;
-
-package body Interfaces.C.Pointers is
-
- type Addr is mod Memory_Size;
-
- function To_Pointer is new Unchecked_Conversion (Addr, Pointer);
- function To_Addr is new Unchecked_Conversion (Pointer, Addr);
- function To_Addr is new Unchecked_Conversion (ptrdiff_t, Addr);
- function To_Ptrdiff is new Unchecked_Conversion (Addr, ptrdiff_t);
-
- Elmt_Size : constant ptrdiff_t :=
- (Element_Array'Component_Size
- + Storage_Unit - 1) / Storage_Unit;
-
- subtype Index_Base is Index'Base;
-
- ---------
- -- "+" --
- ---------
-
- function "+" (Left : in Pointer; Right : in ptrdiff_t) return Pointer is
- begin
- if Left = null then
- raise Pointer_Error;
- end if;
-
- return To_Pointer (To_Addr (Left) + To_Addr (Elmt_Size * Right));
- end "+";
-
- function "+" (Left : in ptrdiff_t; Right : in Pointer) return Pointer is
- begin
- if Right = null then
- raise Pointer_Error;
- end if;
-
- return To_Pointer (To_Addr (Elmt_Size * Left) + To_Addr (Right));
- end "+";
-
- ---------
- -- "-" --
- ---------
-
- function "-" (Left : in Pointer; Right : in ptrdiff_t) return Pointer is
- begin
- if Left = null then
- raise Pointer_Error;
- end if;
-
- return To_Pointer (To_Addr (Left) - To_Addr (Right * Elmt_Size));
- end "-";
-
- function "-" (Left : in Pointer; Right : in Pointer) return ptrdiff_t is
- begin
- if Left = null or else Right = null then
- raise Pointer_Error;
- end if;
-
- return To_Ptrdiff (To_Addr (Left) - To_Addr (Right)) / Elmt_Size;
- end "-";
-
- ----------------
- -- Copy_Array --
- ----------------
-
- procedure Copy_Array
- (Source : in Pointer;
- Target : in Pointer;
- Length : in ptrdiff_t)
- is
- T : Pointer := Target;
- S : Pointer := Source;
-
- begin
- if S = null or else T = null then
- raise Dereference_Error;
-
- else
- for J in 1 .. Length loop
- T.all := S.all;
- Increment (T);
- Increment (S);
- end loop;
- end if;
- end Copy_Array;
-
- ---------------------------
- -- Copy_Terminated_Array --
- ---------------------------
-
- procedure Copy_Terminated_Array
- (Source : in Pointer;
- Target : in Pointer;
- Limit : in ptrdiff_t := ptrdiff_t'Last;
- Terminator : in Element := Default_Terminator)
- is
- S : Pointer := Source;
- T : Pointer := Target;
- L : ptrdiff_t := Limit;
-
- begin
- if S = null or else T = null then
- raise Dereference_Error;
-
- else
- while L > 0 loop
- T.all := S.all;
- exit when T.all = Terminator;
- Increment (T);
- Increment (S);
- L := L - 1;
- end loop;
- end if;
- end Copy_Terminated_Array;
-
- ---------------
- -- Decrement --
- ---------------
-
- procedure Decrement (Ref : in out Pointer) is
- begin
- Ref := Ref - 1;
- end Decrement;
-
- ---------------
- -- Increment --
- ---------------
-
- procedure Increment (Ref : in out Pointer) is
- begin
- Ref := Ref + 1;
- end Increment;
-
- -----------
- -- Value --
- -----------
-
- function Value
- (Ref : in Pointer;
- Terminator : in Element := Default_Terminator)
- return Element_Array
- is
- P : Pointer;
- L : constant Index_Base := Index'First;
- H : Index_Base;
-
- begin
- if Ref = null then
- raise Dereference_Error;
-
- else
- H := L;
- P := Ref;
-
- loop
- exit when P.all = Terminator;
- H := Index_Base'Succ (H);
- Increment (P);
- end loop;
-
- declare
- subtype A is Element_Array (L .. H);
-
- type PA is access A;
- function To_PA is new Unchecked_Conversion (Pointer, PA);
-
- begin
- return To_PA (Ref).all;
- end;
- end if;
- end Value;
-
- function Value
- (Ref : in Pointer;
- Length : in ptrdiff_t)
- return Element_Array
- is
- L : Index_Base;
- H : Index_Base;
-
- begin
- if Ref = null then
- raise Dereference_Error;
-
- -- For length zero, we need to return a null slice, but we can't make
- -- the bounds of this slice Index'First, since this could cause a
- -- Constraint_Error if Index'First = Index'Base'First.
-
- elsif Length <= 0 then
- declare
- pragma Warnings (Off); -- kill warnings since X not assigned
- X : Element_Array (Index'Succ (Index'First) .. Index'First);
- pragma Warnings (On);
-
- begin
- return X;
- end;
-
- -- Normal case (length non-zero)
-
- else
- L := Index'First;
- H := Index'Val (Index'Pos (Index'First) + Length - 1);
-
- declare
- subtype A is Element_Array (L .. H);
-
- type PA is access A;
- function To_PA is new Unchecked_Conversion (Pointer, PA);
-
- begin
- return To_PA (Ref).all;
- end;
- end if;
- end Value;
-
- --------------------
- -- Virtual_Length --
- --------------------
-
- function Virtual_Length
- (Ref : in Pointer;
- Terminator : in Element := Default_Terminator)
- return ptrdiff_t
- is
- P : Pointer;
- C : ptrdiff_t;
-
- begin
- if Ref = null then
- raise Dereference_Error;
-
- else
- C := 0;
- P := Ref;
-
- while P.all /= Terminator loop
- C := C + 1;
- Increment (P);
- end loop;
-
- return C;
- end if;
- end Virtual_Length;
-
-end Interfaces.C.Pointers;
projects / msp430-gcc.git / blobdiff