1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . C A L E N D A R --
9 -- Copyright (C) 1997-2002 Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- This is the Windows NT/95 version.
36 with System.OS_Primitives;
39 with System.OS_Interface;
41 package body Ada.Calendar is
43 use System.OS_Interface;
45 ------------------------------
46 -- Use of Pragma Unsuppress --
47 ------------------------------
49 -- This implementation of Calendar takes advantage of the permission in
50 -- Ada 95 of using arithmetic overflow checks to check for out of bounds
51 -- time values. This means that we must catch the constraint error that
52 -- results from arithmetic overflow, so we use pragma Unsuppress to make
53 -- sure that overflow is enabled, using software overflow checking if
54 -- necessary. That way, compiling Calendar with options to suppress this
55 -- checking will not affect its correctness.
57 ------------------------
58 -- Local Declarations --
59 ------------------------
61 Ada_Year_Min : constant := 1901;
62 Ada_Year_Max : constant := 2099;
64 -- Win32 time constants
66 epoch_1970 : constant := 16#19D_B1DE_D53E_8000#; -- win32 UTC epoch
67 system_time_ns : constant := 100; -- 100 ns per tick
68 Sec_Unit : constant := 10#1#E9;
74 function "+" (Left : Time; Right : Duration) return Time is
75 pragma Unsuppress (Overflow_Check);
77 return (Left + Time (Right));
80 when Constraint_Error =>
84 function "+" (Left : Duration; Right : Time) return Time is
85 pragma Unsuppress (Overflow_Check);
87 return (Time (Left) + Right);
90 when Constraint_Error =>
98 function "-" (Left : Time; Right : Duration) return Time is
99 pragma Unsuppress (Overflow_Check);
101 return Left - Time (Right);
104 when Constraint_Error =>
108 function "-" (Left : Time; Right : Time) return Duration is
109 pragma Unsuppress (Overflow_Check);
111 return Duration (Left) - Duration (Right);
114 when Constraint_Error =>
122 function "<" (Left, Right : Time) return Boolean is
124 return Duration (Left) < Duration (Right);
131 function "<=" (Left, Right : Time) return Boolean is
133 return Duration (Left) <= Duration (Right);
140 function ">" (Left, Right : Time) return Boolean is
142 return Duration (Left) > Duration (Right);
149 function ">=" (Left, Right : Time) return Boolean is
151 return Duration (Left) >= Duration (Right);
158 -- The Ada.Calendar.Clock function gets the time from the soft links
159 -- interface which will call the appropriate function depending wether
160 -- tasking is involved or not.
162 function Clock return Time is
164 return Time (System.OS_Primitives.Clock);
171 function Day (Date : Time) return Day_Number is
178 Split (Date, DY, DM, DD, DS);
186 function Month (Date : Time) return Month_Number is
193 Split (Date, DY, DM, DD, DS);
201 function Seconds (Date : Time) return Day_Duration is
208 Split (Date, DY, DM, DD, DS);
218 Year : out Year_Number;
219 Month : out Month_Number;
220 Day : out Day_Number;
221 Seconds : out Day_Duration)
224 Date_Int : aliased Long_Long_Integer;
225 Date_Loc : aliased Long_Long_Integer;
226 Timbuf : aliased SYSTEMTIME;
227 Int_Date : Long_Long_Integer;
228 Sub_Seconds : Duration;
231 -- We take the sub-seconds (decimal part) of Date and this is added
232 -- to compute the Seconds. This way we keep the precision of the
233 -- high-precision clock that was lost with the Win32 API calls
238 -- this is a Date before Epoch (January 1st, 1970)
240 Sub_Seconds := Duration (Date) -
241 Duration (Long_Long_Integer (Date + Duration'(0.5)));
243 Int_Date := Long_Long_Integer (Date - Sub_Seconds);
245 -- For Date = -86400.1 we are 2 days before Epoch at 0.1 seconds
246 -- from day 1 before Epoch. It means that it is 23h 59m 59.9s.
247 -- here we adjust for that.
249 if Sub_Seconds < 0.0 then
250 Int_Date := Int_Date - 1;
251 Sub_Seconds := 1.0 + Sub_Seconds;
256 -- this is a Date after Epoch (January 1st, 1970)
258 Sub_Seconds := Duration (Date) -
259 Duration (Long_Long_Integer (Date - Duration'(0.5)));
261 Int_Date := Long_Long_Integer (Date - Sub_Seconds);
265 -- Date_Int is the number of seconds from Epoch.
267 Date_Int := Long_Long_Integer
268 (Int_Date * Sec_Unit / system_time_ns) + epoch_1970;
270 if not FileTimeToLocalFileTime (Date_Int'Access, Date_Loc'Access) then
274 if not FileTimeToSystemTime (Date_Loc'Access, Timbuf'Access) then
278 if Timbuf.wYear not in Ada_Year_Min .. Ada_Year_Max then
283 Duration (Timbuf.wHour) * 3_600.0 +
284 Duration (Timbuf.wMinute) * 60.0 +
285 Duration (Timbuf.wSecond) +
288 Day := Integer (Timbuf.wDay);
289 Month := Integer (Timbuf.wMonth);
290 Year := Integer (Timbuf.wYear);
299 Month : Month_Number;
301 Seconds : Day_Duration := 0.0)
305 Timbuf : aliased SYSTEMTIME;
306 Now : aliased Long_Long_Integer;
307 Loc : aliased Long_Long_Integer;
310 Add_One_Day : Boolean := False;
314 -- The following checks are redundant with respect to the constraint
315 -- error checks that should normally be made on parameters, but we
316 -- decide to raise Constraint_Error in any case if bad values come
317 -- in (as a result of checks being off in the caller, or for other
318 -- erroneous or bounded error cases).
321 or else not Month 'Valid
322 or else not Day 'Valid
323 or else not Seconds'Valid
325 raise Constraint_Error;
328 if Seconds = 0.0 then
331 Int_Secs := Integer (Seconds - 0.5);
334 -- Timbuf.wMillisec is to keep the msec. We can't use that because the
335 -- high-resolution clock has a precision of 1 Microsecond.
336 -- Anyway the sub-seconds part is not needed to compute the number
337 -- of seconds in UTC.
339 if Int_Secs = 86_400 then
346 Timbuf.wMilliseconds := 0;
347 Timbuf.wSecond := WORD (Secs mod 60);
348 Timbuf.wMinute := WORD ((Secs / 60) mod 60);
349 Timbuf.wHour := WORD (Secs / 3600);
350 Timbuf.wDay := WORD (Day);
351 Timbuf.wMonth := WORD (Month);
352 Timbuf.wYear := WORD (Year);
354 if not SystemTimeToFileTime (Timbuf'Access, Loc'Access) then
358 if not LocalFileTimeToFileTime (Loc'Access, Now'Access) then
362 -- Here we have the UTC now translate UTC to Epoch time (UNIX style
363 -- time based on 1 january 1970) and add there the sub-seconds part.
366 Sub_Sec : constant Duration := Seconds - Duration (Int_Secs);
368 Date := Time ((Now - epoch_1970) * system_time_ns / Sec_Unit) +
373 Date := Date + Duration (86400.0);
383 function Year (Date : Time) return Year_Number is
390 Split (Date, DY, DM, DD, DS);