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diff --git a/gcc/ada/libgnat/a-stuten.ads b/gcc/ada/libgnat/a-stuten.ads new file mode 100644 index 00000000000..fba30dfee8a --- /dev/null +++ b/gcc/ada/libgnat/a-stuten.ads @@ -0,0 +1,144 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- A D A . S T R I N G S . U T F _ E N C O D I N G -- +-- -- +-- S p e c -- +-- -- +-- This specification is derived from the Ada Reference Manual for use with -- +-- GNAT. The copyright notice above, and the license provisions that follow -- +-- apply solely to the contents of the part following the private keyword. -- +-- -- +-- 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This is one of the Ada 2012 package defined in AI05-0137-1. It is a parent +-- package that contains declarations used in the child packages for handling +-- UTF encoded strings. Note: this package is consistent with Ada 95, and may +-- be used in Ada 95 or Ada 2005 mode. + +with Interfaces; +with Unchecked_Conversion; + +package Ada.Strings.UTF_Encoding is + pragma Pure (UTF_Encoding); + + subtype UTF_String is String; + -- Used to represent a string of 8-bit values containing a sequence of + -- values encoded in one of three ways (UTF-8, UTF-16BE, or UTF-16LE). + -- Typically used in connection with a Scheme parameter indicating which + -- of the encodings applies. This is not strictly a String value in the + -- sense defined in the Ada RM, but in practice type String accommodates + -- all possible 256 codes, and can be used to hold any sequence of 8-bit + -- codes. We use String directly rather than create a new type so that + -- all existing facilities for manipulating type String (e.g. the child + -- packages of Ada.Strings) are available for manipulation of UTF_Strings. + + type Encoding_Scheme is (UTF_8, UTF_16BE, UTF_16LE); + -- Used to specify which of three possible encodings apply to a UTF_String + + subtype UTF_8_String is String; + -- Similar to UTF_String but specifically represents a UTF-8 encoded string + + subtype UTF_16_Wide_String is Wide_String; + -- This is similar to UTF_8_String but is used to represent a Wide_String + -- value which is a sequence of 16-bit values encoded using UTF-16. Again + -- this is not strictly a Wide_String in the sense of the Ada RM, but the + -- type Wide_String can be used to represent a sequence of arbitrary 16-bit + -- values, and it is more convenient to use Wide_String than a new type. + + Encoding_Error : exception; + -- This exception is raised in the following situations: + -- a) A UTF encoded string contains an invalid encoding sequence + -- b) A UTF-16BE or UTF-16LE input string has an odd length + -- c) An incorrect character value is present in the Input string + -- d) The result for a Wide_Character output exceeds 16#FFFF# + -- The exception message has the index value where the error occurred. + + -- The BOM (BYTE_ORDER_MARK) values defined here are used at the start of + -- a string to indicate the encoding. The convention in this package is + -- that on input a correct BOM is ignored and an incorrect BOM causes an + -- Encoding_Error exception. On output, the output string may or may not + -- include a BOM depending on the setting of Output_BOM. + + BOM_8 : constant UTF_8_String := + Character'Val (16#EF#) & + Character'Val (16#BB#) & + Character'Val (16#BF#); + + BOM_16BE : constant UTF_String := + Character'Val (16#FE#) & + Character'Val (16#FF#); + + BOM_16LE : constant UTF_String := + Character'Val (16#FF#) & + Character'Val (16#FE#); + + BOM_16 : constant UTF_16_Wide_String := + (1 => Wide_Character'Val (16#FEFF#)); + + function Encoding + (Item : UTF_String; + Default : Encoding_Scheme := UTF_8) return Encoding_Scheme; + -- This function inspects a UTF_String value to determine whether it + -- starts with a BOM for UTF-8, UTF-16BE, or UTF_16LE. If so, the result + -- is the scheme corresponding to the BOM. If no valid BOM is present + -- then the result is the specified Default value. + +private + function To_Unsigned_8 is new + Unchecked_Conversion (Character, Interfaces.Unsigned_8); + + function To_Unsigned_16 is new + Unchecked_Conversion (Wide_Character, Interfaces.Unsigned_16); + + function To_Unsigned_32 is new + Unchecked_Conversion (Wide_Wide_Character, Interfaces.Unsigned_32); + + subtype UTF_XE_Encoding is Encoding_Scheme range UTF_16BE .. UTF_16LE; + -- Subtype containing only UTF_16BE and UTF_16LE entries + + -- Utility routines for converting between UTF-16 and UTF-16LE/BE + + function From_UTF_16 + (Item : UTF_16_Wide_String; + Output_Scheme : UTF_XE_Encoding; + Output_BOM : Boolean := False) return UTF_String; + -- The input string Item is encoded in UTF-16. The output is encoded using + -- Output_Scheme (which is either UTF-16LE or UTF-16BE). There are no error + -- cases. The output starts with BOM_16BE/LE if Output_BOM is True. + + function To_UTF_16 + (Item : UTF_String; + Input_Scheme : UTF_XE_Encoding; + Output_BOM : Boolean := False) return UTF_16_Wide_String; + -- The input string Item is encoded using Input_Scheme which is either + -- UTF-16LE or UTF-16BE. The output is the corresponding UTF_16 wide + -- string. Encoding error is raised if the length of the input is odd. + -- The output starts with BOM_16 if Output_BOM is True. + + procedure Raise_Encoding_Error (Index : Natural); + pragma No_Return (Raise_Encoding_Error); + -- Raise Encoding_Error exception for bad encoding in input item. The + -- parameter Index is the index of the location in Item for the error. + +end Ada.Strings.UTF_Encoding; |