diff options
Diffstat (limited to 'gcc-4.4.3/gcc/ada/g-byorma.ads')
| -rwxr-xr-x | gcc-4.4.3/gcc/ada/g-byorma.ads | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/gcc-4.4.3/gcc/ada/g-byorma.ads b/gcc-4.4.3/gcc/ada/g-byorma.ads new file mode 100755 index 000000000..6016f755b --- /dev/null +++ b/gcc-4.4.3/gcc/ada/g-byorma.ads @@ -0,0 +1,104 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- G N A T . B Y T E _ O R D E R _ M A R K -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2006-2007, AdaCore -- +-- -- +-- 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, 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, -- +-- 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. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides a procedure for reading and interpreting the BOM +-- (byte order mark) used to publish the encoding method for a string (for +-- example, a UTF-8 encoded file in windows will start with the appropriate +-- BOM sequence to signal UTF-8 encoding. + +-- There are two cases + +-- Case 1. UTF encodings for Unicode files + +-- Here the convention is to have the first character of the file be a +-- non-breaking zero width space character (16#0000_FEFF#). For the UTF +-- encodings, the representation of this character can be used to uniquely +-- determine the encoding. Furthermore, the possibility of any confusion +-- with unencoded files is minimal, since for example the UTF-8 encoding +-- of this character looks like the sequence: + +-- LC_I_Diaeresis +-- Right_Angle_Quotation +-- Fraction_One_Half + +-- which is so unlikely to occur legitimately in normal use that it can +-- safely be ignored in most cases (for example, no legitimate Ada source +-- file could start with this sequence of characters). + +-- Case 2. Specialized XML encodings + +-- The XML standard defines a number of other possible encodings and also +-- defines standardized sequences for marking these encodings. This package +-- can also optionally handle these XML defined BOM sequences. These XML +-- cases depend on the first character of the XML file being < so that the +-- encoding of this character can be recognized. + +pragma Warnings (Off); +pragma Compiler_Unit; +pragma Warnings (On); + +package GNAT.Byte_Order_Mark is + + type BOM_Kind is + (UTF8_All, -- UTF8-encoding + UTF16_LE, -- UTF16 little-endian encoding + UTF16_BE, -- UTF16 big-endian encoding + UTF32_LE, -- UTF32 little-endian encoding + UTF32_BE, -- UTF32 big-endian encoding + + -- The following cases are for XML only + + UCS4_BE, -- UCS-4, big endian machine (1234 order) + UCS4_LE, -- UCS-4, little endian machine (4321 order) + UCS4_2143, -- UCS-4, unusual byte order (2143 order) + UCS4_3412, -- UCS-4, unusual byte order (3412 order) + + -- Value returned if no BOM recognized + + Unknown); -- Unknown, assumed to be ASCII compatible + + procedure Read_BOM + (Str : String; + Len : out Natural; + BOM : out BOM_Kind; + XML_Support : Boolean := False); + -- This is the routine to read the BOM from the start of the given string + -- Str. On return BOM is set to the appropriate BOM_Kind and Len is set to + -- its length. The caller will typically skip the first Len characters in + -- the string to ignore the BOM sequence. The special XML possibilities are + -- recognized only if flag XML_Support is set to True. Note that for the + -- XML cases, Len is always set to zero on return (not to the length of the + -- relevant sequence) since in the XML cases, the sequence recognized is + -- for the first real character in the file (<) which is not to be skipped. + +end GNAT.Byte_Order_Mark; |