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Diffstat (limited to 'gcc/ada/i-cstrin.adb')
| -rw-r--r-- | gcc/ada/i-cstrin.adb | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/gcc/ada/i-cstrin.adb b/gcc/ada/i-cstrin.adb new file mode 100644 index 00000000000..4c0f166ce67 --- /dev/null +++ b/gcc/ada/i-cstrin.adb @@ -0,0 +1,329 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- I N T E R F A C E S . C . S T R I N G S -- +-- -- +-- B o d y -- +-- -- +-- $Revision: 1.21 $ +-- -- +-- Copyright (C) 1992-2000 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. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with System; use System; +with System.Address_To_Access_Conversions; + +package body Interfaces.C.Strings is + + package Char_Access is new Address_To_Access_Conversions (char); + + ----------------------- + -- Local Subprograms -- + ----------------------- + + function Peek (From : chars_ptr) return char; + pragma Inline (Peek); + -- Given a chars_ptr value, obtain referenced character + + procedure Poke (Value : char; Into : chars_ptr); + pragma Inline (Poke); + -- Given a chars_ptr, modify referenced Character value + + function "+" (Left : chars_ptr; Right : size_t) return chars_ptr; + pragma Inline ("+"); + -- Address arithmetic on chars_ptr value + + function Position_Of_Nul (Into : char_array) return size_t; + -- Returns position of the first Nul in Into or Into'Last + 1 if none + + function C_Malloc (Size : size_t) return chars_ptr; + pragma Import (C, C_Malloc, "__gnat_malloc"); + + procedure C_Free (Address : chars_ptr); + pragma Import (C, C_Free, "__gnat_free"); + + --------- + -- "+" -- + --------- + + function "+" (Left : chars_ptr; Right : size_t) return chars_ptr is + begin + return Left + chars_ptr (Right); + end "+"; + + ---------- + -- Free -- + ---------- + + procedure Free (Item : in out chars_ptr) is + begin + if Item = Null_Ptr then + return; + end if; + + C_Free (Item); + Item := Null_Ptr; + end Free; + + -------------------- + -- New_Char_Array -- + -------------------- + + function New_Char_Array (Chars : in char_array) return chars_ptr is + Index : size_t; + Pointer : chars_ptr; + + begin + -- Get index of position of null. If Index > Chars'last, + -- nul is absent and must be added explicitly. + + Index := Position_Of_Nul (Into => Chars); + Pointer := C_Malloc ((Index - Chars'First + 1)); + + -- If nul is present, transfer string up to and including it. + + if Index <= Chars'Last then + Update (Item => Pointer, + Offset => 0, + Chars => Chars (Chars'First .. Index), + Check => False); + else + -- If original string has no nul, transfer whole string and add + -- terminator explicitly. + + Update (Item => Pointer, + Offset => 0, + Chars => Chars, + Check => False); + Poke (nul, into => Pointer + size_t '(Chars'Length)); + end if; + + return Pointer; + end New_Char_Array; + + ---------------- + -- New_String -- + ---------------- + + function New_String (Str : in String) return chars_ptr is + begin + return New_Char_Array (To_C (Str)); + end New_String; + + ---------- + -- Peek -- + ---------- + + function Peek (From : chars_ptr) return char is + use Char_Access; + begin + return To_Pointer (Address (To_Address (From))).all; + end Peek; + + ---------- + -- Poke -- + ---------- + + procedure Poke (Value : char; Into : chars_ptr) is + use Char_Access; + begin + To_Pointer (Address (To_Address (Into))).all := Value; + end Poke; + + --------------------- + -- Position_Of_Nul -- + --------------------- + + function Position_Of_Nul (Into : char_array) return size_t is + begin + for J in Into'Range loop + if Into (J) = nul then + return J; + end if; + end loop; + + return Into'Last + 1; + end Position_Of_Nul; + + ------------ + -- Strlen -- + ------------ + + function Strlen (Item : in chars_ptr) return size_t is + Item_Index : size_t := 0; + + begin + if Item = Null_Ptr then + raise Dereference_Error; + end if; + + loop + if Peek (Item + Item_Index) = nul then + return Item_Index; + end if; + + Item_Index := Item_Index + 1; + end loop; + end Strlen; + + ------------------ + -- To_Chars_Ptr -- + ------------------ + + function To_Chars_Ptr + (Item : in char_array_access; + Nul_Check : in Boolean := False) + return chars_ptr + is + begin + if Item = null then + return Null_Ptr; + elsif Nul_Check + and then Position_Of_Nul (Into => Item.all) > Item'Last + then + raise Terminator_Error; + else + return To_Integer (Item (Item'First)'Address); + end if; + end To_Chars_Ptr; + + ------------ + -- Update -- + ------------ + + procedure Update + (Item : in chars_ptr; + Offset : in size_t; + Chars : in char_array; + Check : Boolean := True) + is + Index : chars_ptr := Item + Offset; + + begin + if Check and then Offset + Chars'Length > Strlen (Item) then + raise Update_Error; + end if; + + for J in Chars'Range loop + Poke (Chars (J), Into => Index); + Index := Index + size_t'(1); + end loop; + end Update; + + procedure Update + (Item : in chars_ptr; + Offset : in size_t; + Str : in String; + Check : in Boolean := True) + is + begin + Update (Item, Offset, To_C (Str), Check); + end Update; + + ----------- + -- Value -- + ----------- + + function Value (Item : in chars_ptr) return char_array is + Result : char_array (0 .. Strlen (Item)); + + begin + if Item = Null_Ptr then + raise Dereference_Error; + end if; + + -- Note that the following loop will also copy the terminating Nul + + for J in Result'Range loop + Result (J) := Peek (Item + J); + end loop; + + return Result; + end Value; + + function Value + (Item : in chars_ptr; + Length : in size_t) + return char_array + is + begin + if Item = Null_Ptr then + raise Dereference_Error; + end if; + + -- ACATS cxb3010 checks that Constraint_Error gets raised when Length + -- is 0. Seems better to check that Length is not null before declaring + -- an array with size_t bounds of 0 .. Length - 1 anyway. + + if Length = 0 then + raise Constraint_Error; + end if; + + declare + Result : char_array (0 .. Length - 1); + + begin + for J in Result'Range loop + Result (J) := Peek (Item + J); + + if Result (J) = nul then + return Result (0 .. J); + end if; + end loop; + + return Result; + end; + end Value; + + function Value (Item : in 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 + Result : char_array (0 .. Length); + + begin + if Item = Null_Ptr then + raise Dereference_Error; + end if; + + for J in 0 .. Length - 1 loop + Result (J) := Peek (Item + J); + + if Result (J) = nul then + return To_Ada (Result (0 .. J)); + end if; + end loop; + + Result (Length) := nul; + return To_Ada (Result); + end Value; + +end Interfaces.C.Strings; |