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Diffstat (limited to 'gcc/ada/libgnat/s-valuef.ads')
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diff --git a/gcc/ada/libgnat/s-valuef.ads b/gcc/ada/libgnat/s-valuef.ads new file mode 100644 index 0000000..fac8c23 --- /dev/null +++ b/gcc/ada/libgnat/s-valuef.ads @@ -0,0 +1,94 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S Y S T E M . V A L U E _ F -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2020, 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 the routines for supporting the Value attribute for +-- ordinary fixed point types, and also for conversion operations required in +-- Text_IO.Fixed_IO for such types. + +generic + + type Int is range <>; + + type Uns is mod <>; + + with procedure Scaled_Divide + (X, Y, Z : Int; + Q, R : out Int; + Round : Boolean); + +package System.Value_F is + pragma Preelaborate; + + function Scan_Fixed + (Str : String; + Ptr : not null access Integer; + Max : Integer; + Num : Int; + Den : Int) return Int; + -- This function scans the string starting at Str (Ptr.all) for a valid + -- real literal according to the syntax described in (RM 3.5(43)). The + -- substring scanned extends no further than Str (Max). There are three + -- cases for the return: + -- + -- If a valid real literal is found after scanning past any initial spaces, + -- then Ptr.all is updated past the last character of the literal (but + -- trailing spaces are not scanned out). The value returned is the value + -- Int'Integer_Value (decimal-literal-value), using the given Num/Den to + -- determine this value. + -- + -- If no valid real literal 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: if Str is null, 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. + + function Value_Fixed + (Str : String; + Num : Int; + Den : Int) return Int; + -- Used in computing X'Value (Str) where X is an ordinary fixed-point type. + -- 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 of Int (not + -- the range of the fixed-point type, which must be done by the caller). + -- Otherwise the value returned is the value Int'Integer_Value + -- (decimal-literal-value), using Small Num/Den to determine this value. + +end System.Value_F; |