-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2005, 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- --
-- 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. --
+-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
+-- Boston, MA 02110-1301, 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, --
package body Interfaces.C.Strings is
+ -- Note that the type chars_ptr has a pragma No_Strict_Aliasing in the
+ -- spec, to prevent any assumptions about aliasing for values of this type,
+ -- since arbitrary addresses can be converted, and it is quite likely that
+ -- this type will in fact be used for aliasing values of other types.
+
function To_chars_ptr is
new Unchecked_Conversion (Address, chars_ptr);
-- New_Char_Array --
--------------------
- function New_Char_Array (Chars : in char_array) return chars_ptr is
+ function New_Char_Array (Chars : char_array) return chars_ptr is
Index : size_t;
Pointer : chars_ptr;
Index := Position_Of_Nul (Into => Chars);
Pointer := Memory_Alloc ((Index - Chars'First + 1));
- -- If nul is present, transfer string up to and including it.
+ -- If nul is present, transfer string up to and including nul
if Index <= Chars'Last then
Update (Item => Pointer,
-- New_String --
----------------
- function New_String (Str : in String) return chars_ptr is
+ function New_String (Str : String) return chars_ptr is
begin
return New_Char_Array (To_C (Str));
end New_String;
-- Strlen --
------------
- function Strlen (Item : in chars_ptr) return size_t is
+ function Strlen (Item : chars_ptr) return size_t is
Item_Index : size_t := 0;
begin
------------------
function To_Chars_Ptr
- (Item : in char_array_access;
- Nul_Check : in Boolean := False)
- return chars_ptr
+ (Item : char_array_access;
+ Nul_Check : Boolean := False) return chars_ptr
is
begin
if Item = null then
raise Terminator_Error;
else
return To_chars_ptr (Item (Item'First)'Address);
-
end if;
end To_Chars_Ptr;
------------
procedure Update
- (Item : in chars_ptr;
- Offset : in size_t;
- Chars : in char_array;
+ (Item : chars_ptr;
+ Offset : size_t;
+ Chars : char_array;
Check : Boolean := True)
is
Index : chars_ptr := Item + Offset;
end Update;
procedure Update
- (Item : in chars_ptr;
- Offset : in size_t;
- Str : in String;
- Check : in Boolean := True)
+ (Item : chars_ptr;
+ Offset : size_t;
+ Str : String;
+ Check : Boolean := True)
is
begin
- Update (Item, Offset, To_C (Str), Check);
+ -- Note: in RM 95, the Append_Nul => False parameter is omitted. But
+ -- this has the unintended consequence of truncating the string after
+ -- an update. As discussed in Ada 2005 AI-242, this was unintended,
+ -- and should be corrected. Since this is a clear error, it seems
+ -- appropriate to apply the correction in Ada 95 mode as well.
+
+ Update (Item, Offset, To_C (Str, Append_Nul => False), Check);
end Update;
-----------
-- Value --
-----------
- function Value (Item : in chars_ptr) return char_array is
+ function Value (Item : chars_ptr) return char_array is
Result : char_array (0 .. Strlen (Item));
begin
end Value;
function Value
- (Item : in chars_ptr;
- Length : in size_t)
- return char_array
+ (Item : chars_ptr;
+ Length : size_t) return char_array
is
begin
if Item = Null_Ptr then
end;
end Value;
- function Value (Item : in chars_ptr) return String is
+ function Value (Item : chars_ptr) return String is
begin
return To_Ada (Value (Item));
end Value;
- -- As per AI-00177, this is equivalent to
- -- To_Ada (Value (Item, Length) & nul);
-
- function Value (Item : in chars_ptr; Length : in size_t) return String is
+ function Value (Item : chars_ptr; Length : size_t) return String is
Result : char_array (0 .. Length);
begin
+ -- As per AI-00177, this is equivalent to:
+
+ -- To_Ada (Value (Item, Length) & nul);
+
if Item = Null_Ptr then
raise Dereference_Error;
end if;