1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . C A L E N D A R --
9 -- Copyright (C) 1992-2009, 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 3, 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- This is the Alpha/VMS version
34 with Ada.Unchecked_Conversion;
36 with System.Aux_DEC; use System.Aux_DEC;
37 with System.OS_Primitives; use System.OS_Primitives;
39 package body Ada.Calendar is
41 --------------------------
42 -- Implementation Notes --
43 --------------------------
45 -- Variables of type Ada.Calendar.Time have suffix _S or _M to denote
46 -- units of seconds or milis.
48 -- Because time is measured in different units and from different origins
49 -- on various targets, a system independent model is incorporated into
50 -- Ada.Calendar. The idea behind the design is to encapsulate all target
51 -- dependent machinery in a single package, thus providing a uniform
52 -- interface to all existing and any potential children.
54 -- package Ada.Calendar
55 -- procedure Split (5 parameters) -------+
56 -- | Call from local routine
58 -- package Formatting_Operations |
59 -- procedure Split (11 parameters) <--+
60 -- end Formatting_Operations |
63 -- package Ada.Calendar.Formatting | Call from child routine
64 -- procedure Split (9 or 10 parameters) -+
65 -- end Ada.Calendar.Formatting
67 -- The behaviour of the interfacing routines is controlled via various
68 -- flags. All new Ada 2005 types from children of Ada.Calendar are
69 -- emulated by a similar type. For instance, type Day_Number is replaced
70 -- by Integer in various routines. One ramification of this model is that
71 -- the caller site must perform validity checks on returned results.
72 -- The end result of this model is the lack of target specific files per
73 -- child of Ada.Calendar (a-calfor, a-calfor-vms, a-calfor-vxwors, etc).
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 procedure Check_Within_Time_Bounds (T : OS_Time);
80 -- Ensure that a time representation value falls withing the bounds of Ada
81 -- time. Leap seconds support is taken into account.
83 procedure Cumulative_Leap_Seconds
84 (Start_Date : OS_Time;
86 Elapsed_Leaps : out Natural;
87 Next_Leap_Sec : out OS_Time);
88 -- Elapsed_Leaps is the sum of the leap seconds that have occurred on or
89 -- after Start_Date and before (strictly before) End_Date. Next_Leap_Sec
90 -- represents the next leap second occurrence on or after End_Date. If
91 -- there are no leaps seconds after End_Date, End_Of_Time is returned.
92 -- End_Of_Time can be used as End_Date to count all the leap seconds that
93 -- have occurred on or after Start_Date.
95 -- Note: Any sub seconds of Start_Date and End_Date are discarded before
96 -- the calculations are done. For instance: if 113 seconds is a leap
97 -- second (it isn't) and 113.5 is input as an End_Date, the leap second
98 -- at 113 will not be counted in Leaps_Between, but it will be returned
99 -- as Next_Leap_Sec. Thus, if the caller wants to know if the End_Date is
100 -- a leap second, the comparison should be:
102 -- End_Date >= Next_Leap_Sec;
104 -- After_Last_Leap is designed so that this comparison works without
105 -- having to first check if Next_Leap_Sec is a valid leap second.
107 function To_Duration (T : Time) return Duration;
108 function To_Relative_Time (D : Duration) return Time;
109 -- It is important to note that duration's fractional part denotes nano
110 -- seconds while the units of Time are 100 nanoseconds. If a regular
111 -- Unchecked_Conversion was employed, the resulting values would be off
114 --------------------------
115 -- Leap seconds control --
116 --------------------------
119 pragma Import (C, Flag, "__gl_leap_seconds_support");
120 -- This imported value is used to determine whether the compilation had
121 -- binder flag "-y" present which enables leap seconds. A value of zero
122 -- signifies no leap seconds support while a value of one enables the
125 Leap_Support : constant Boolean := Flag = 1;
126 -- The above flag controls the usage of leap seconds in all Ada.Calendar
129 Leap_Seconds_Count : constant Natural := 24;
131 ---------------------
132 -- Local Constants --
133 ---------------------
135 -- The range of Ada time expressed as milis since the VMS Epoch
137 Ada_Low : constant OS_Time := (10 * 366 + 32 * 365 + 45) * Milis_In_Day;
138 Ada_High : constant OS_Time := (131 * 366 + 410 * 365 + 45) * Milis_In_Day;
140 -- Even though the upper bound of time is 2399-12-31 23:59:59.9999999
141 -- UTC, it must be increased to include all leap seconds.
143 Ada_High_And_Leaps : constant OS_Time :=
144 Ada_High + OS_Time (Leap_Seconds_Count) * Mili;
146 -- Two constants used in the calculations of elapsed leap seconds.
147 -- End_Of_Time is later than Ada_High in time zone -28. Start_Of_Time
148 -- is earlier than Ada_Low in time zone +28.
150 End_Of_Time : constant OS_Time := Ada_High + OS_Time (3) * Milis_In_Day;
151 Start_Of_Time : constant OS_Time := Ada_Low - OS_Time (3) * Milis_In_Day;
153 -- The following table contains the hard time values of all existing leap
154 -- seconds. The values are produced by the utility program xleaps.adb.
156 Leap_Second_Times : constant array (1 .. Leap_Seconds_Count) of OS_Time :=
186 function "+" (Left : Time; Right : Duration) return Time is
187 pragma Unsuppress (Overflow_Check);
189 return Left + To_Relative_Time (Right);
191 when Constraint_Error =>
195 function "+" (Left : Duration; Right : Time) return Time is
196 pragma Unsuppress (Overflow_Check);
200 when Constraint_Error =>
208 function "-" (Left : Time; Right : Duration) return Time is
209 pragma Unsuppress (Overflow_Check);
211 return Left - To_Relative_Time (Right);
213 when Constraint_Error =>
217 function "-" (Left : Time; Right : Time) return Duration is
218 pragma Unsuppress (Overflow_Check);
220 -- The bound of type Duration expressed as time
222 Dur_High : constant OS_Time :=
223 OS_Time (To_Relative_Time (Duration'Last));
224 Dur_Low : constant OS_Time :=
225 OS_Time (To_Relative_Time (Duration'First));
230 Res_M := OS_Time (Left) - OS_Time (Right);
232 -- Due to the extended range of Ada time, "-" is capable of producing
233 -- results which may exceed the range of Duration. In order to prevent
234 -- the generation of bogus values by the Unchecked_Conversion, we apply
235 -- the following check.
238 or else Res_M >= Dur_High
242 -- Normal case, result fits
245 return To_Duration (Time (Res_M));
249 when Constraint_Error =>
257 function "<" (Left, Right : Time) return Boolean is
259 return OS_Time (Left) < OS_Time (Right);
266 function "<=" (Left, Right : Time) return Boolean is
268 return OS_Time (Left) <= OS_Time (Right);
275 function ">" (Left, Right : Time) return Boolean is
277 return OS_Time (Left) > OS_Time (Right);
284 function ">=" (Left, Right : Time) return Boolean is
286 return OS_Time (Left) >= OS_Time (Right);
289 ------------------------------
290 -- Check_Within_Time_Bounds --
291 ------------------------------
293 procedure Check_Within_Time_Bounds (T : OS_Time) is
296 if T < Ada_Low or else T > Ada_High_And_Leaps then
300 if T < Ada_Low or else T > Ada_High then
304 end Check_Within_Time_Bounds;
310 function Clock return Time is
311 Elapsed_Leaps : Natural;
312 Next_Leap_M : OS_Time;
313 Res_M : constant OS_Time := OS_Clock;
316 -- Note that on other targets a soft-link is used to get a different
317 -- clock depending whether tasking is used or not. On VMS this isn't
318 -- needed since all clock calls end up using SYS$GETTIM, so call the
319 -- OS_Primitives version for efficiency.
321 -- If the target supports leap seconds, determine the number of leap
322 -- seconds elapsed until this moment.
325 Cumulative_Leap_Seconds
326 (Start_Of_Time, Res_M, Elapsed_Leaps, Next_Leap_M);
328 -- The system clock may fall exactly on a leap second
330 if Res_M >= Next_Leap_M then
331 Elapsed_Leaps := Elapsed_Leaps + 1;
334 -- The target does not support leap seconds
340 return Time (Res_M + OS_Time (Elapsed_Leaps) * Mili);
343 -----------------------------
344 -- Cumulative_Leap_Seconds --
345 -----------------------------
347 procedure Cumulative_Leap_Seconds
348 (Start_Date : OS_Time;
350 Elapsed_Leaps : out Natural;
351 Next_Leap_Sec : out OS_Time)
353 End_Index : Positive;
354 End_T : OS_Time := End_Date;
355 Start_Index : Positive;
356 Start_T : OS_Time := Start_Date;
359 pragma Assert (Leap_Support and then End_Date >= Start_Date);
361 Next_Leap_Sec := End_Of_Time;
363 -- Make sure that the end date does not exceed the upper bound
366 if End_Date > Ada_High then
370 -- Remove the sub seconds from both dates
372 Start_T := Start_T - (Start_T mod Mili);
373 End_T := End_T - (End_T mod Mili);
375 -- Some trivial cases:
376 -- Leap 1 . . . Leap N
377 -- ---+========+------+############+-------+========+-----
378 -- Start_T End_T Start_T End_T
380 if End_T < Leap_Second_Times (1) then
382 Next_Leap_Sec := Leap_Second_Times (1);
385 elsif Start_T > Leap_Second_Times (Leap_Seconds_Count) then
387 Next_Leap_Sec := End_Of_Time;
391 -- Perform the calculations only if the start date is within the leap
392 -- second occurrences table.
394 if Start_T <= Leap_Second_Times (Leap_Seconds_Count) then
397 -- +----+----+-- . . . --+-------+---+
398 -- | T1 | T2 | | N - 1 | N |
399 -- +----+----+-- . . . --+-------+---+
401 -- | Start_Index | End_Index
402 -- +-------------------+
405 -- The idea behind the algorithm is to iterate and find two closest
406 -- dates which are after Start_T and End_T. Their corresponding
407 -- index difference denotes the number of leap seconds elapsed.
411 exit when Leap_Second_Times (Start_Index) >= Start_T;
412 Start_Index := Start_Index + 1;
415 End_Index := Start_Index;
417 exit when End_Index > Leap_Seconds_Count
418 or else Leap_Second_Times (End_Index) >= End_T;
419 End_Index := End_Index + 1;
422 if End_Index <= Leap_Seconds_Count then
423 Next_Leap_Sec := Leap_Second_Times (End_Index);
426 Elapsed_Leaps := End_Index - Start_Index;
431 end Cumulative_Leap_Seconds;
437 function Day (Date : Time) return Day_Number is
442 pragma Unreferenced (Y, M, S);
444 Split (Date, Y, M, D, S);
452 function Is_Leap (Year : Year_Number) return Boolean is
454 -- Leap centennial years
456 if Year mod 400 = 0 then
459 -- Non-leap centennial years
461 elsif Year mod 100 = 0 then
467 return Year mod 4 = 0;
475 function Month (Date : Time) return Month_Number is
480 pragma Unreferenced (Y, D, S);
482 Split (Date, Y, M, D, S);
490 function Seconds (Date : Time) return Day_Duration is
495 pragma Unreferenced (Y, M, D);
497 Split (Date, Y, M, D, S);
507 Year : out Year_Number;
508 Month : out Month_Number;
509 Day : out Day_Number;
510 Seconds : out Day_Duration)
519 -- Use UTC as the local time zone on VMS, the status of flag Is_Ada_05
520 -- is irrelevant in this case.
522 Formatting_Operations.Split
539 or else not Month'Valid
540 or else not Day'Valid
541 or else not Seconds'Valid
553 Month : Month_Number;
555 Seconds : Day_Duration := 0.0) return Time
557 -- The values in the following constants are irrelevant, they are just
558 -- placeholders; the choice of constructing a Day_Duration value is
559 -- controlled by the Use_Day_Secs flag.
561 H : constant Integer := 1;
562 M : constant Integer := 1;
563 Se : constant Integer := 1;
564 Ss : constant Duration := 0.1;
568 or else not Month'Valid
569 or else not Day'Valid
570 or else not Seconds'Valid
575 -- Use UTC as the local time zone on VMS, the status of flag Is_Ada_05
576 -- is irrelevant in this case.
579 Formatting_Operations.Time_Of
589 Use_Day_Secs => True,
598 function To_Duration (T : Time) return Duration is
599 function Time_To_Duration is
600 new Ada.Unchecked_Conversion (Time, Duration);
602 return Time_To_Duration (T * 100);
605 ----------------------
606 -- To_Relative_Time --
607 ----------------------
609 function To_Relative_Time (D : Duration) return Time is
610 function Duration_To_Time is
611 new Ada.Unchecked_Conversion (Duration, Time);
613 return Duration_To_Time (D / 100.0);
614 end To_Relative_Time;
620 function Year (Date : Time) return Year_Number is
625 pragma Unreferenced (M, D, S);
627 Split (Date, Y, M, D, S);
631 -- The following packages assume that Time is a Long_Integer, the units
632 -- are 100 nanoseconds and the starting point in the VMS Epoch.
634 ---------------------------
635 -- Arithmetic_Operations --
636 ---------------------------
638 package body Arithmetic_Operations is
644 function Add (Date : Time; Days : Long_Integer) return Time is
645 pragma Unsuppress (Overflow_Check);
646 Date_M : constant OS_Time := OS_Time (Date);
648 return Time (Date_M + OS_Time (Days) * Milis_In_Day);
650 when Constraint_Error =>
661 Days : out Long_Integer;
662 Seconds : out Duration;
663 Leap_Seconds : out Integer)
668 Elapsed_Leaps : Natural;
670 Negate : Boolean := False;
672 Sub_Seconds : Duration;
675 -- This classification is necessary in order to avoid a Time_Error
676 -- being raised by the arithmetic operators in Ada.Calendar.
678 if Left >= Right then
679 Later := OS_Time (Left);
680 Earlier := OS_Time (Right);
682 Later := OS_Time (Right);
683 Earlier := OS_Time (Left);
687 -- If the target supports leap seconds, process them
690 Cumulative_Leap_Seconds
691 (Earlier, Later, Elapsed_Leaps, Next_Leap);
693 if Later >= Next_Leap then
694 Elapsed_Leaps := Elapsed_Leaps + 1;
697 -- The target does not support leap seconds
703 Diff_M := Later - Earlier - OS_Time (Elapsed_Leaps) * Mili;
705 -- Sub second processing
707 Sub_Seconds := Duration (Diff_M mod Mili) / Mili_F;
709 -- Convert to seconds. Note that his action eliminates the sub
710 -- seconds automatically.
712 Diff_S := Diff_M / Mili;
714 Days := Long_Integer (Diff_S / Secs_In_Day);
715 Seconds := Duration (Diff_S mod Secs_In_Day) + Sub_Seconds;
716 Leap_Seconds := Integer (Elapsed_Leaps);
722 if Leap_Seconds /= 0 then
723 Leap_Seconds := -Leap_Seconds;
732 function Subtract (Date : Time; Days : Long_Integer) return Time is
733 pragma Unsuppress (Overflow_Check);
734 Date_M : constant OS_Time := OS_Time (Date);
736 return Time (Date_M - OS_Time (Days) * Milis_In_Day);
738 when Constraint_Error =>
741 end Arithmetic_Operations;
743 ---------------------------
744 -- Conversion_Operations --
745 ---------------------------
747 package body Conversion_Operations is
749 Epoch_Offset : constant OS_Time := 35067168000000000;
750 -- The difference between 1970-1-1 UTC and 1858-11-17 UTC expressed in
757 function To_Ada_Time (Unix_Time : Long_Integer) return Time is
758 pragma Unsuppress (Overflow_Check);
759 Unix_Rep : constant OS_Time := OS_Time (Unix_Time) * Mili;
761 return Time (Unix_Rep + Epoch_Offset);
763 when Constraint_Error =>
778 tm_isdst : Integer) return Time
780 pragma Unsuppress (Overflow_Check);
782 Year_Shift : constant Integer := 1900;
783 Month_Shift : constant Integer := 1;
786 Month : Month_Number;
795 Year := Year_Number (Year_Shift + tm_year);
796 Month := Month_Number (Month_Shift + tm_mon);
797 Day := Day_Number (tm_day);
799 -- Step 1: Validity checks of input values
802 or else not Month'Valid
803 or else not Day'Valid
804 or else tm_hour not in 0 .. 24
805 or else tm_min not in 0 .. 59
806 or else tm_sec not in 0 .. 60
807 or else tm_isdst not in -1 .. 1
812 -- Step 2: Potential leap second
822 -- Step 3: Calculate the time value
826 (Formatting_Operations.Time_Of
830 Day_Secs => 0.0, -- Time is given in h:m:s
834 Sub_Sec => 0.0, -- No precise sub second given
836 Use_Day_Secs => False, -- Time is given in h:m:s
837 Is_Ada_05 => True, -- Force usage of explicit time zone
838 Time_Zone => 0)); -- Place the value in UTC
839 -- Step 4: Daylight Savings Time
842 Result := Result + OS_Time (3_600) * Mili;
845 return Time (Result);
847 when Constraint_Error =>
856 (tv_sec : Long_Integer;
857 tv_nsec : Long_Integer) return Duration
859 pragma Unsuppress (Overflow_Check);
861 return Duration (tv_sec) + Duration (tv_nsec) / Mili_F;
864 ------------------------
865 -- To_Struct_Timespec --
866 ------------------------
868 procedure To_Struct_Timespec
870 tv_sec : out Long_Integer;
871 tv_nsec : out Long_Integer)
873 pragma Unsuppress (Overflow_Check);
875 Nano_Secs : Duration;
878 -- Seconds extraction, avoid potential rounding errors
881 tv_sec := Long_Integer (Secs);
883 -- 100 Nanoseconds extraction
885 Nano_Secs := D - Duration (tv_sec);
886 tv_nsec := Long_Integer (Nano_Secs * Mili);
887 end To_Struct_Timespec;
893 procedure To_Struct_Tm
895 tm_year : out Integer;
896 tm_mon : out Integer;
897 tm_day : out Integer;
898 tm_hour : out Integer;
899 tm_min : out Integer;
900 tm_sec : out Integer)
902 pragma Unsuppress (Overflow_Check);
904 Month : Month_Number;
906 Day_Secs : Day_Duration;
911 -- Step 1: Split the input time
913 Formatting_Operations.Split
914 (T, Year, Month, tm_day, Day_Secs,
915 tm_hour, tm_min, Second, Sub_Sec, Leap_Sec, True, 0);
917 -- Step 2: Correct the year and month
919 tm_year := Year - 1900;
922 -- Step 3: Handle leap second occurrences
924 tm_sec := (if Leap_Sec then 60 else Second);
931 function To_Unix_Time (Ada_Time : Time) return Long_Integer is
932 pragma Unsuppress (Overflow_Check);
933 Ada_OS_Time : constant OS_Time := OS_Time (Ada_Time);
935 return Long_Integer ((Ada_OS_Time - Epoch_Offset) / Mili);
937 when Constraint_Error =>
940 end Conversion_Operations;
942 ---------------------------
943 -- Formatting_Operations --
944 ---------------------------
946 package body Formatting_Operations is
952 function Day_Of_Week (Date : Time) return Integer is
958 Day_Count : Long_Integer;
959 Midday_Date_S : Time;
962 Split (Date, Y, M, D, S);
964 -- Build a time value in the middle of the same day and convert the
965 -- time value to seconds.
967 Midday_Date_S := Time_Of (Y, M, D, 43_200.0) / Mili;
969 -- Count the number of days since the start of VMS time. 1858-11-17
972 Day_Count := Long_Integer (Midday_Date_S / Secs_In_Day) + 2;
974 return Integer (Day_Count mod 7);
983 Year : out Year_Number;
984 Month : out Month_Number;
985 Day : out Day_Number;
986 Day_Secs : out Day_Duration;
988 Minute : out Integer;
989 Second : out Integer;
990 Sub_Sec : out Duration;
991 Leap_Sec : out Boolean;
993 Time_Zone : Long_Integer)
995 -- The flag Is_Ada_05 is present for interfacing purposes
997 pragma Unreferenced (Is_Ada_05);
1000 (Status : out Unsigned_Longword;
1001 Timbuf : out Unsigned_Word_Array;
1004 pragma Interface (External, Numtim);
1006 pragma Import_Valued_Procedure
1007 (Numtim, "SYS$NUMTIM",
1008 (Unsigned_Longword, Unsigned_Word_Array, Time),
1009 (Value, Reference, Reference));
1011 Status : Unsigned_Longword;
1012 Timbuf : Unsigned_Word_Array (1 .. 7);
1014 Ada_Min_Year : constant := 1901;
1015 Ada_Max_Year : constant := 2399;
1018 Elapsed_Leaps : Natural;
1019 Next_Leap_M : OS_Time;
1022 Date_M := OS_Time (Date);
1024 -- Step 1: Leap seconds processing
1026 if Leap_Support then
1027 Cumulative_Leap_Seconds
1028 (Start_Of_Time, Date_M, Elapsed_Leaps, Next_Leap_M);
1030 Leap_Sec := Date_M >= Next_Leap_M;
1033 Elapsed_Leaps := Elapsed_Leaps + 1;
1036 -- The target does not support leap seconds
1043 Date_M := Date_M - OS_Time (Elapsed_Leaps) * Mili;
1045 -- Step 2: Time zone processing
1047 if Time_Zone /= 0 then
1048 Date_M := Date_M + OS_Time (Time_Zone) * 60 * Mili;
1051 -- After the leap seconds and time zone have been accounted for,
1052 -- the date should be within the bounds of Ada time.
1055 or else Date_M > Ada_High
1060 -- Step 3: Sub second processing
1062 Sub_Sec := Duration (Date_M mod Mili) / Mili_F;
1064 -- Drop the sub seconds
1066 Date_M := Date_M - (Date_M mod Mili);
1068 -- Step 4: VMS system call
1070 Numtim (Status, Timbuf, Time (Date_M));
1072 if Status mod 2 /= 1
1073 or else Timbuf (1) not in Ada_Min_Year .. Ada_Max_Year
1078 -- Step 5: Time components processing
1080 Year := Year_Number (Timbuf (1));
1081 Month := Month_Number (Timbuf (2));
1082 Day := Day_Number (Timbuf (3));
1083 Hour := Integer (Timbuf (4));
1084 Minute := Integer (Timbuf (5));
1085 Second := Integer (Timbuf (6));
1087 Day_Secs := Day_Duration (Hour * 3_600) +
1088 Day_Duration (Minute * 60) +
1089 Day_Duration (Second) +
1098 (Year : Year_Number;
1099 Month : Month_Number;
1101 Day_Secs : Day_Duration;
1106 Leap_Sec : Boolean := False;
1107 Use_Day_Secs : Boolean := False;
1108 Is_Ada_05 : Boolean := False;
1109 Time_Zone : Long_Integer := 0) return Time
1111 procedure Cvt_Vectim
1112 (Status : out Unsigned_Longword;
1113 Input_Time : Unsigned_Word_Array;
1114 Resultant_Time : out Time);
1116 pragma Interface (External, Cvt_Vectim);
1118 pragma Import_Valued_Procedure
1119 (Cvt_Vectim, "LIB$CVT_VECTIM",
1120 (Unsigned_Longword, Unsigned_Word_Array, Time),
1121 (Value, Reference, Reference));
1123 Status : Unsigned_Longword;
1124 Timbuf : Unsigned_Word_Array (1 .. 7);
1126 Y : Year_Number := Year;
1127 Mo : Month_Number := Month;
1128 D : Day_Number := Day;
1129 H : Integer := Hour;
1130 Mi : Integer := Minute;
1131 Se : Integer := Second;
1132 Su : Duration := Sub_Sec;
1134 Elapsed_Leaps : Natural;
1135 Int_Day_Secs : Integer;
1136 Next_Leap_M : OS_Time;
1139 Rounded_Res_M : OS_Time;
1142 -- No validity checks are performed on the input values since it is
1143 -- assumed that the called has already performed them.
1145 -- Step 1: Hour, minute, second and sub second processing
1147 if Use_Day_Secs then
1149 -- A day seconds value of 86_400 designates a new day
1151 if Day_Secs = 86_400.0 then
1153 Adj_Year : Year_Number := Year;
1154 Adj_Month : Month_Number := Month;
1155 Adj_Day : Day_Number := Day;
1158 if Day < Days_In_Month (Month)
1160 and then Is_Leap (Year))
1164 -- The day adjustment moves the date to a new month
1170 Adj_Month := Month + 1;
1172 -- The month adjustment moves the date to a new year
1176 Adj_Year := Year + 1;
1189 -- Normal case (not exactly one day)
1192 -- Sub second extraction
1196 then Integer (Day_Secs - 0.5)
1197 else Integer (Day_Secs));
1199 H := Int_Day_Secs / 3_600;
1200 Mi := (Int_Day_Secs / 60) mod 60;
1201 Se := Int_Day_Secs mod 60;
1202 Su := Day_Secs - Duration (Int_Day_Secs);
1206 -- Step 2: System call to VMS
1208 Timbuf (1) := Unsigned_Word (Y);
1209 Timbuf (2) := Unsigned_Word (Mo);
1210 Timbuf (3) := Unsigned_Word (D);
1211 Timbuf (4) := Unsigned_Word (H);
1212 Timbuf (5) := Unsigned_Word (Mi);
1213 Timbuf (6) := Unsigned_Word (Se);
1216 Cvt_Vectim (Status, Timbuf, Res);
1218 if Status mod 2 /= 1 then
1222 -- Step 3: Sub second adjustment
1224 Res_M := OS_Time (Res) + OS_Time (Su * Mili_F);
1226 -- Step 4: Bounds check
1228 Check_Within_Time_Bounds (Res_M);
1230 -- Step 5: Time zone processing
1232 if Time_Zone /= 0 then
1233 Res_M := Res_M - OS_Time (Time_Zone) * 60 * Mili;
1236 -- Step 6: Leap seconds processing
1238 if Leap_Support then
1239 Cumulative_Leap_Seconds
1240 (Start_Of_Time, Res_M, Elapsed_Leaps, Next_Leap_M);
1242 Res_M := Res_M + OS_Time (Elapsed_Leaps) * Mili;
1244 -- An Ada 2005 caller requesting an explicit leap second or an
1245 -- Ada 95 caller accounting for an invisible leap second.
1248 or else Res_M >= Next_Leap_M
1250 Res_M := Res_M + OS_Time (1) * Mili;
1253 -- Leap second validity check
1255 Rounded_Res_M := Res_M - (Res_M mod Mili);
1259 and then Rounded_Res_M /= Next_Leap_M
1265 return Time (Res_M);
1267 end Formatting_Operations;
1269 ---------------------------
1270 -- Time_Zones_Operations --
1271 ---------------------------
1273 package body Time_Zones_Operations is
1275 ---------------------
1276 -- UTC_Time_Offset --
1277 ---------------------
1279 function UTC_Time_Offset (Date : Time) return Long_Integer is
1280 -- Formal parameter Date is here for interfacing, but is never
1283 pragma Unreferenced (Date);
1285 function get_gmtoff return Long_Integer;
1286 pragma Import (C, get_gmtoff, "get_gmtoff");
1289 -- VMS is not capable of determining the time zone in some past or
1290 -- future point in time denoted by Date, thus the current time zone
1294 end UTC_Time_Offset;
1295 end Time_Zones_Operations;