130 lines
6.6 KiB
Ada
130 lines
6.6 KiB
Ada
|
------------------------------------------------------------------------------
|
||
|
|
-- --
|
||
|
|
-- GNAT COMPILER COMPONENTS --
|
||
|
|
-- --
|
||
|
|
-- S Y S T E M . V A L _ L L U --
|
||
|
|
-- --
|
||
|
|
-- S p e c --
|
||
|
|
-- --
|
||
|
|
-- Copyright (C) 1992-2015, 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 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 package contains routines for scanning modular Long_Long_Unsigned
|
||
|
|
-- values for use in Text_IO.Modular_IO, and the Value attribute.
|
||
|
|
|
||
|
|
with System.Unsigned_Types;
|
||
|
|
|
||
|
|
package System.Val_LLU is
|
||
|
|
pragma Pure;
|
||
|
|
|
||
|
|
function Scan_Raw_Long_Long_Unsigned
|
||
|
|
(Str : String;
|
||
|
|
Ptr : not null access Integer;
|
||
|
|
Max : Integer) return System.Unsigned_Types.Long_Long_Unsigned;
|
||
|
|
-- This function scans the string starting at Str (Ptr.all) for a valid
|
||
|
|
-- integer according to the syntax described in (RM 3.5(43)). The substring
|
||
|
|
-- scanned extends no further than Str (Max). Note: this does not scan
|
||
|
|
-- leading or trailing blanks, nor leading sign.
|
||
|
|
--
|
||
|
|
-- There are three cases for the return:
|
||
|
|
--
|
||
|
|
-- If a valid integer is found, then Ptr.all is updated past the last
|
||
|
|
-- character of the integer.
|
||
|
|
--
|
||
|
|
-- If no valid integer is found, then Ptr.all points either to an initial
|
||
|
|
-- non-digit character, or to Max + 1 if the field is all spaces and the
|
||
|
|
-- exception Constraint_Error is raised.
|
||
|
|
--
|
||
|
|
-- If a syntactically valid integer is scanned, but the value is out of
|
||
|
|
-- range, or, in the based case, the base value is out of range or there
|
||
|
|
-- is an out of range digit, then Ptr.all points past the integer, and
|
||
|
|
-- Constraint_Error is raised.
|
||
|
|
--
|
||
|
|
-- Note: these rules correspond to the requirements for leaving the pointer
|
||
|
|
-- positioned in Text_IO.Get. Note that the rules as stated in the RM would
|
||
|
|
-- seem to imply that for a case like:
|
||
|
|
--
|
||
|
|
-- 8#12345670009#
|
||
|
|
--
|
||
|
|
-- the pointer should be left at the first # having scanned out the longest
|
||
|
|
-- valid integer literal (8), but in fact in this case the pointer points
|
||
|
|
-- past the final # and Constraint_Error is raised. This is the behavior
|
||
|
|
-- expected for Text_IO and enforced by the ACATS tests.
|
||
|
|
--
|
||
|
|
-- If a based literal is malformed in that a character other than a valid
|
||
|
|
-- hexadecimal digit is encountered during scanning out the digits after
|
||
|
|
-- the # (this includes the case of using the wrong terminator, : instead
|
||
|
|
-- of # or vice versa) there are two cases. If all the digits before the
|
||
|
|
-- non-digit are in range of the base, as in
|
||
|
|
--
|
||
|
|
-- 8#100x00#
|
||
|
|
-- 8#100:
|
||
|
|
--
|
||
|
|
-- then in this case, the "base" value before the initial # is returned as
|
||
|
|
-- the result, and the pointer points to the initial # character on return.
|
||
|
|
--
|
||
|
|
-- If an out of range digit has been detected before the invalid character,
|
||
|
|
-- as in:
|
||
|
|
--
|
||
|
|
-- 8#900x00#
|
||
|
|
-- 8#900:
|
||
|
|
--
|
||
|
|
-- then the pointer is also left at the initial # character, but constraint
|
||
|
|
-- error is raised reflecting the encounter of an out of range digit.
|
||
|
|
--
|
||
|
|
-- Finally if we have an unterminated fixed-point constant where the final
|
||
|
|
-- # or : character is missing, Constraint_Error is raised and the pointer
|
||
|
|
-- is left pointing past the last digit, as in:
|
||
|
|
--
|
||
|
|
-- 8#22
|
||
|
|
--
|
||
|
|
-- This string results in a Constraint_Error with the pointer pointing
|
||
|
|
-- past the second 2.
|
||
|
|
--
|
||
|
|
-- Note: if Str is empty, i.e. if Max is less than Ptr, then this is a
|
||
|
|
-- special case of an all-blank string, and Ptr is unchanged, and hence
|
||
|
|
-- is greater than Max as required in this case.
|
||
|
|
--
|
||
|
|
-- Note: this routine should not be called with Str'Last = Positive'Last.
|
||
|
|
-- If this occurs Program_Error is raised with a message noting that this
|
||
|
|
-- case is not supported. Most such cases are eliminated by the caller.
|
||
|
|
|
||
|
|
function Scan_Long_Long_Unsigned
|
||
|
|
(Str : String;
|
||
|
|
Ptr : not null access Integer;
|
||
|
|
Max : Integer) return System.Unsigned_Types.Long_Long_Unsigned;
|
||
|
|
-- Same as Scan_Raw_Long_Long_Unsigned, except scans optional leading
|
||
|
|
-- blanks, and an optional leading plus sign.
|
||
|
|
--
|
||
|
|
-- Note: if a minus sign is present, Constraint_Error will be raised.
|
||
|
|
-- Note: trailing blanks are not scanned.
|
||
|
|
|
||
|
|
function Value_Long_Long_Unsigned
|
||
|
|
(Str : String) return System.Unsigned_Types.Long_Long_Unsigned;
|
||
|
|
-- Used in computing X'Value (Str) where X is a modular integer type whose
|
||
|
|
-- modulus exceeds the range of System.Unsigned_Types.Unsigned. Str is the
|
||
|
|
-- string argument of the attribute. Constraint_Error is raised if the
|
||
|
|
-- string is malformed, or if the value is out of range.
|
||
|
|
|
||
|
|
end System.Val_LLU;
|