1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . C A L E N D A R --
10 -- Copyright (C) 1997-2001 Free Software Foundation, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNAT was originally developed by the GNAT team at New York University. --
31 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
33 ------------------------------------------------------------------------------
35 -- This is the Windows NT/95 version.
37 with System.OS_Primitives;
40 with System.OS_Interface;
42 package body Ada.Calendar is
44 use System.OS_Interface;
46 ------------------------------
47 -- Use of Pragma Unsuppress --
48 ------------------------------
50 -- This implementation of Calendar takes advantage of the permission in
51 -- Ada 95 of using arithmetic overflow checks to check for out of bounds
52 -- time values. This means that we must catch the constraint error that
53 -- results from arithmetic overflow, so we use pragma Unsuppress to make
54 -- sure that overflow is enabled, using software overflow checking if
55 -- necessary. That way, compiling Calendar with options to suppress this
56 -- checking will not affect its correctness.
58 ------------------------
59 -- Local Declarations --
60 ------------------------
62 Ada_Year_Min : constant := 1901;
63 Ada_Year_Max : constant := 2099;
65 -- Win32 time constants
67 epoch_1970 : constant := 16#19D_B1DE_D53E_8000#; -- win32 UTC epoch
68 system_time_ns : constant := 100; -- 100 ns per tick
69 Sec_Unit : constant := 10#1#E9;
75 function "+" (Left : Time; Right : Duration) return Time is
76 pragma Unsuppress (Overflow_Check);
78 return (Left + Time (Right));
81 when Constraint_Error =>
85 function "+" (Left : Duration; Right : Time) return Time is
86 pragma Unsuppress (Overflow_Check);
88 return (Time (Left) + Right);
91 when Constraint_Error =>
99 function "-" (Left : Time; Right : Duration) return Time is
100 pragma Unsuppress (Overflow_Check);
102 return Left - Time (Right);
105 when Constraint_Error =>
109 function "-" (Left : Time; Right : Time) return Duration is
110 pragma Unsuppress (Overflow_Check);
112 return Duration (Left) - Duration (Right);
115 when Constraint_Error =>
123 function "<" (Left, Right : Time) return Boolean is
125 return Duration (Left) < Duration (Right);
132 function "<=" (Left, Right : Time) return Boolean is
134 return Duration (Left) <= Duration (Right);
141 function ">" (Left, Right : Time) return Boolean is
143 return Duration (Left) > Duration (Right);
150 function ">=" (Left, Right : Time) return Boolean is
152 return Duration (Left) >= Duration (Right);
159 -- The Ada.Calendar.Clock function gets the time from the soft links
160 -- interface which will call the appropriate function depending wether
161 -- tasking is involved or not.
163 function Clock return Time is
165 return Time (System.OS_Primitives.Clock);
172 function Day (Date : Time) return Day_Number is
179 Split (Date, DY, DM, DD, DS);
187 function Month (Date : Time) return Month_Number is
194 Split (Date, DY, DM, DD, DS);
202 function Seconds (Date : Time) return Day_Duration is
209 Split (Date, DY, DM, DD, DS);
219 Year : out Year_Number;
220 Month : out Month_Number;
221 Day : out Day_Number;
222 Seconds : out Day_Duration)
225 Date_Int : aliased Long_Long_Integer;
226 Date_Loc : aliased Long_Long_Integer;
227 Timbuf : aliased SYSTEMTIME;
228 Int_Date : Long_Long_Integer;
229 Sub_Seconds : Duration;
232 -- We take the sub-seconds (decimal part) of Date and this is added
233 -- to compute the Seconds. This way we keep the precision of the
234 -- high-precision clock that was lost with the Win32 API calls
239 -- this is a Date before Epoch (January 1st, 1970)
241 Sub_Seconds := Duration (Date) -
242 Duration (Long_Long_Integer (Date + Duration'(0.5)));
244 Int_Date := Long_Long_Integer (Date - Sub_Seconds);
246 -- For Date = -86400.1 we are 2 days before Epoch at 0.1 seconds
247 -- from day 1 before Epoch. It means that it is 23h 59m 59.9s.
248 -- here we adjust for that.
250 if Sub_Seconds < 0.0 then
251 Int_Date := Int_Date - 1;
252 Sub_Seconds := 1.0 + Sub_Seconds;
257 -- this is a Date after Epoch (January 1st, 1970)
259 Sub_Seconds := Duration (Date) -
260 Duration (Long_Long_Integer (Date - Duration'(0.5)));
262 Int_Date := Long_Long_Integer (Date - Sub_Seconds);
266 -- Date_Int is the number of seconds from Epoch.
268 Date_Int := Long_Long_Integer
269 (Int_Date * Sec_Unit / system_time_ns) + epoch_1970;
271 if not FileTimeToLocalFileTime (Date_Int'Access, Date_Loc'Access) then
275 if not FileTimeToSystemTime (Date_Loc'Access, Timbuf'Access) then
279 if Timbuf.wYear not in Ada_Year_Min .. Ada_Year_Max then
284 Duration (Timbuf.wHour) * 3_600.0 +
285 Duration (Timbuf.wMinute) * 60.0 +
286 Duration (Timbuf.wSecond) +
289 Day := Integer (Timbuf.wDay);
290 Month := Integer (Timbuf.wMonth);
291 Year := Integer (Timbuf.wYear);
300 Month : Month_Number;
302 Seconds : Day_Duration := 0.0)
306 Timbuf : aliased SYSTEMTIME;
307 Now : aliased Long_Long_Integer;
308 Loc : aliased Long_Long_Integer;
311 Add_One_Day : Boolean := False;
315 -- The following checks are redundant with respect to the constraint
316 -- error checks that should normally be made on parameters, but we
317 -- decide to raise Constraint_Error in any case if bad values come
318 -- in (as a result of checks being off in the caller, or for other
319 -- erroneous or bounded error cases).
322 or else not Month 'Valid
323 or else not Day 'Valid
324 or else not Seconds'Valid
326 raise Constraint_Error;
329 if Seconds = 0.0 then
332 Int_Secs := Integer (Seconds - 0.5);
335 -- Timbuf.wMillisec is to keep the msec. We can't use that because the
336 -- high-resolution clock has a precision of 1 Microsecond.
337 -- Anyway the sub-seconds part is not needed to compute the number
338 -- of seconds in UTC.
340 if Int_Secs = 86_400 then
347 Timbuf.wMilliseconds := 0;
348 Timbuf.wSecond := WORD (Secs mod 60);
349 Timbuf.wMinute := WORD ((Secs / 60) mod 60);
350 Timbuf.wHour := WORD (Secs / 3600);
351 Timbuf.wDay := WORD (Day);
352 Timbuf.wMonth := WORD (Month);
353 Timbuf.wYear := WORD (Year);
355 if not SystemTimeToFileTime (Timbuf'Access, Loc'Access) then
359 if not LocalFileTimeToFileTime (Loc'Access, Now'Access) then
363 -- Here we have the UTC now translate UTC to Epoch time (UNIX style
364 -- time based on 1 january 1970) and add there the sub-seconds part.
367 Sub_Sec : Duration := Seconds - Duration (Int_Secs);
369 Date := Time ((Now - epoch_1970) * system_time_ns / Sec_Unit) +
374 Date := Date + Duration (86400.0);
384 function Year (Date : Time) return Year_Number is
391 Split (Date, DY, DM, DD, DS);