-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, 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 2, or (at your option) any later ver- --
+-- 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. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- 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 is the Alpha/VMS version
-with System.Aux_DEC; use System.Aux_DEC;
-
with Ada.Unchecked_Conversion;
+with System.Aux_DEC; use System.Aux_DEC;
+with System.OS_Primitives; use System.OS_Primitives;
+
package body Ada.Calendar is
--------------------------
-- Because time is measured in different units and from different origins
-- on various targets, a system independent model is incorporated into
- -- Ada.Calendar. The idea behing the design is to encapsulate all target
+ -- Ada.Calendar. The idea behind the design is to encapsulate all target
-- dependent machinery in a single package, thus providing a uniform
-- interface to all existing and any potential children.
-- Local Subprograms --
-----------------------
- procedure Check_Within_Time_Bounds (T : Time);
+ procedure Check_Within_Time_Bounds (T : OS_Time);
-- Ensure that a time representation value falls withing the bounds of Ada
-- time. Leap seconds support is taken into account.
procedure Cumulative_Leap_Seconds
- (Start_Date : Time;
- End_Date : Time;
+ (Start_Date : OS_Time;
+ End_Date : OS_Time;
Elapsed_Leaps : out Natural;
- Next_Leap_Sec : out Time);
- -- Elapsed_Leaps is the sum of the leap seconds that have occured on or
+ Next_Leap_Sec : out OS_Time);
+ -- Elapsed_Leaps is the sum of the leap seconds that have occurred on or
-- after Start_Date and before (strictly before) End_Date. Next_Leap_Sec
- -- represents the next leap second occurence on or after End_Date. If
+ -- represents the next leap second occurrence on or after End_Date. If
-- there are no leaps seconds after End_Date, End_Of_Time is returned.
-- End_Of_Time can be used as End_Date to count all the leap seconds that
- -- have occured on or after Start_Date.
+ -- have occurred on or after Start_Date.
--
-- Note: Any sub seconds of Start_Date and End_Date are discarded before
-- the calculations are done. For instance: if 113 seconds is a leap
-- Unchecked_Conversion was employed, the resulting values would be off
-- by 100.
+ --------------------------
+ -- Leap seconds control --
+ --------------------------
+
+ Flag : Integer;
+ pragma Import (C, Flag, "__gl_leap_seconds_support");
+ -- This imported value is used to determine whether the compilation had
+ -- binder flag "-y" present which enables leap seconds. A value of zero
+ -- signifies no leap seconds support while a value of one enables the
+ -- support.
+
+ Leap_Support : constant Boolean := Flag = 1;
+ -- The above flag controls the usage of leap seconds in all Ada.Calendar
+ -- routines.
+
+ Leap_Seconds_Count : constant Natural := 24;
+
---------------------
-- Local Constants --
---------------------
- -- Currently none of the GNAT targets support leap seconds. At some point
- -- it might be necessary to query a C function to determine if the target
- -- supports leap seconds, but for now this is deemed unnecessary.
-
- Leap_Support : constant Boolean := False;
- Leap_Seconds_Count : constant Natural := 23;
-
-- The range of Ada time expressed as milis since the VMS Epoch
- Ada_Low : constant Time := (10 * 366 + 32 * 365 + 45) * Milis_In_Day;
- Ada_High : constant Time := (131 * 366 + 410 * 365 + 45) * Milis_In_Day;
+ Ada_Low : constant OS_Time := (10 * 366 + 32 * 365 + 45) * Milis_In_Day;
+ Ada_High : constant OS_Time := (131 * 366 + 410 * 365 + 45) * Milis_In_Day;
-- Even though the upper bound of time is 2399-12-31 23:59:59.9999999
-- UTC, it must be increased to include all leap seconds.
- Ada_High_And_Leaps : constant Time :=
- Ada_High + Time (Leap_Seconds_Count) * Mili;
+ Ada_High_And_Leaps : constant OS_Time :=
+ Ada_High + OS_Time (Leap_Seconds_Count) * Mili;
-- Two constants used in the calculations of elapsed leap seconds.
-- End_Of_Time is later than Ada_High in time zone -28. Start_Of_Time
-- is earlier than Ada_Low in time zone +28.
- End_Of_Time : constant Time := Ada_High + Time (3) * Milis_In_Day;
- Start_Of_Time : constant Time := Ada_Low - Time (3) * Milis_In_Day;
-
- Cumulative_Days_Before_Month :
- constant array (Month_Number) of Natural :=
- (0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334);
-
- Leap_Second_Times : array (1 .. Leap_Seconds_Count) of Time;
- -- Each value represents a time value which is one second before a leap
- -- second occurence. This table is populated during the elaboration of
- -- Ada.Calendar.
+ End_Of_Time : constant OS_Time := Ada_High + OS_Time (3) * Milis_In_Day;
+ Start_Of_Time : constant OS_Time := Ada_Low - OS_Time (3) * Milis_In_Day;
+
+ -- The following table contains the hard time values of all existing leap
+ -- seconds. The values are produced by the utility program xleaps.adb.
+
+ Leap_Second_Times : constant array (1 .. Leap_Seconds_Count) of OS_Time :=
+ (35855136000000000,
+ 36014112010000000,
+ 36329472020000000,
+ 36644832030000000,
+ 36960192040000000,
+ 37276416050000000,
+ 37591776060000000,
+ 37907136070000000,
+ 38222496080000000,
+ 38695104090000000,
+ 39010464100000000,
+ 39325824110000000,
+ 39957408120000000,
+ 40747104130000000,
+ 41378688140000000,
+ 41694048150000000,
+ 42166656160000000,
+ 42482016170000000,
+ 42797376180000000,
+ 43271712190000000,
+ 43744320200000000,
+ 44218656210000000,
+ 46427904220000000,
+ 47374848230000000);
---------
-- "+" --
-- The bound of type Duration expressed as time
- Dur_High : constant Time := To_Relative_Time (Duration'Last);
- Dur_Low : constant Time := To_Relative_Time (Duration'First);
+ Dur_High : constant OS_Time :=
+ OS_Time (To_Relative_Time (Duration'Last));
+ Dur_Low : constant OS_Time :=
+ OS_Time (To_Relative_Time (Duration'First));
- Res_M : Time;
+ Res_M : OS_Time;
begin
- Res_M := Left - Right;
+ Res_M := OS_Time (Left) - OS_Time (Right);
-- Due to the extended range of Ada time, "-" is capable of producing
-- results which may exceed the range of Duration. In order to prevent
-- Normal case, result fits
else
- return To_Duration (Res_M);
+ return To_Duration (Time (Res_M));
end if;
exception
function "<" (Left, Right : Time) return Boolean is
begin
- return Long_Integer (Left) < Long_Integer (Right);
+ return OS_Time (Left) < OS_Time (Right);
end "<";
----------
function "<=" (Left, Right : Time) return Boolean is
begin
- return Long_Integer (Left) <= Long_Integer (Right);
+ return OS_Time (Left) <= OS_Time (Right);
end "<=";
---------
function ">" (Left, Right : Time) return Boolean is
begin
- return Long_Integer (Left) > Long_Integer (Right);
+ return OS_Time (Left) > OS_Time (Right);
end ">";
----------
function ">=" (Left, Right : Time) return Boolean is
begin
- return Long_Integer (Left) >= Long_Integer (Right);
+ return OS_Time (Left) >= OS_Time (Right);
end ">=";
------------------------------
-- Check_Within_Time_Bounds --
------------------------------
- procedure Check_Within_Time_Bounds (T : Time) is
+ procedure Check_Within_Time_Bounds (T : OS_Time) is
begin
if Leap_Support then
if T < Ada_Low or else T > Ada_High_And_Leaps then
function Clock return Time is
Elapsed_Leaps : Natural;
- Next_Leap_M : Time;
- Res_M : constant Time := Time (OSP.OS_Clock);
+ Next_Leap_M : OS_Time;
+ Res_M : constant OS_Time := OS_Clock;
begin
-- Note that on other targets a soft-link is used to get a different
Elapsed_Leaps := 0;
end if;
- return Res_M + Time (Elapsed_Leaps) * Mili;
+ return Time (Res_M + OS_Time (Elapsed_Leaps) * Mili);
end Clock;
-----------------------------
-----------------------------
procedure Cumulative_Leap_Seconds
- (Start_Date : Time;
- End_Date : Time;
+ (Start_Date : OS_Time;
+ End_Date : OS_Time;
Elapsed_Leaps : out Natural;
- Next_Leap_Sec : out Time)
+ Next_Leap_Sec : out OS_Time)
is
End_Index : Positive;
- End_T : Time := End_Date;
+ End_T : OS_Time := End_Date;
Start_Index : Positive;
- Start_T : Time := Start_Date;
+ Start_T : OS_Time := Start_Date;
begin
pragma Assert (Leap_Support and then End_Date >= Start_Date);
Next_Leap_Sec := End_Of_Time;
- -- Make sure that the end date does not excede the upper bound
+ -- Make sure that the end date does not exceed the upper bound
-- of Ada time.
if End_Date > Ada_High then
end if;
-- Perform the calculations only if the start date is within the leap
- -- second occurences table.
+ -- second occurrences table.
if Start_T <= Leap_Second_Times (Leap_Seconds_Count) then
M : Month_Number;
D : Day_Number;
S : Day_Duration;
+ pragma Unreferenced (Y, M, S);
begin
Split (Date, Y, M, D, S);
return D;
function Is_Leap (Year : Year_Number) return Boolean is
begin
- -- Leap centenial years
+ -- Leap centennial years
if Year mod 400 = 0 then
return True;
- -- Non-leap centenial years
+ -- Non-leap centennial years
elsif Year mod 100 = 0 then
return False;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
+ pragma Unreferenced (Y, D, S);
begin
Split (Date, Y, M, D, S);
return M;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
+ pragma Unreferenced (Y, M, D);
begin
Split (Date, Y, M, D, S);
return S;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
+ pragma Unreferenced (M, D, S);
begin
Split (Date, Y, M, D, S);
return Y;
function Add (Date : Time; Days : Long_Integer) return Time is
pragma Unsuppress (Overflow_Check);
+ Date_M : constant OS_Time := OS_Time (Date);
begin
- return Date + Time (Days) * Milis_In_Day;
+ return Time (Date_M + OS_Time (Days) * Milis_In_Day);
exception
when Constraint_Error =>
raise Time_Error;
Seconds : out Duration;
Leap_Seconds : out Integer)
is
- Mili_F : constant Duration := 10_000_000.0;
-
- Diff_M : Time;
- Diff_S : Time;
- Earlier : Time;
+ Diff_M : OS_Time;
+ Diff_S : OS_Time;
+ Earlier : OS_Time;
Elapsed_Leaps : Natural;
- Later : Time;
+ Later : OS_Time;
Negate : Boolean := False;
- Next_Leap : Time;
+ Next_Leap : OS_Time;
Sub_Seconds : Duration;
begin
-- being raised by the arithmetic operators in Ada.Calendar.
if Left >= Right then
- Later := Left;
- Earlier := Right;
+ Later := OS_Time (Left);
+ Earlier := OS_Time (Right);
else
- Later := Right;
- Earlier := Left;
+ Later := OS_Time (Right);
+ Earlier := OS_Time (Left);
Negate := True;
end if;
Elapsed_Leaps := 0;
end if;
- Diff_M := Later - Earlier - Time (Elapsed_Leaps) * Mili;
+ Diff_M := Later - Earlier - OS_Time (Elapsed_Leaps) * Mili;
-- Sub second processing
function Subtract (Date : Time; Days : Long_Integer) return Time is
pragma Unsuppress (Overflow_Check);
+ Date_M : constant OS_Time := OS_Time (Date);
begin
- return Date - Time (Days) * Milis_In_Day;
+ return Time (Date_M - OS_Time (Days) * Milis_In_Day);
exception
when Constraint_Error =>
raise Time_Error;
end Arithmetic_Operations;
---------------------------
+ -- Conversion_Operations --
+ ---------------------------
+
+ package body Conversion_Operations is
+
+ Epoch_Offset : constant OS_Time := 35067168000000000;
+ -- The difference between 1970-1-1 UTC and 1858-11-17 UTC expressed in
+ -- 100 nanoseconds.
+
+ -----------------
+ -- To_Ada_Time --
+ -----------------
+
+ function To_Ada_Time (Unix_Time : Long_Integer) return Time is
+ pragma Unsuppress (Overflow_Check);
+ Unix_Rep : constant OS_Time := OS_Time (Unix_Time) * Mili;
+ begin
+ return Time (Unix_Rep + Epoch_Offset);
+ exception
+ when Constraint_Error =>
+ raise Time_Error;
+ end To_Ada_Time;
+
+ -----------------
+ -- To_Ada_Time --
+ -----------------
+
+ function To_Ada_Time
+ (tm_year : Integer;
+ tm_mon : Integer;
+ tm_day : Integer;
+ tm_hour : Integer;
+ tm_min : Integer;
+ tm_sec : Integer;
+ tm_isdst : Integer) return Time
+ is
+ pragma Unsuppress (Overflow_Check);
+
+ Year_Shift : constant Integer := 1900;
+ Month_Shift : constant Integer := 1;
+
+ Year : Year_Number;
+ Month : Month_Number;
+ Day : Day_Number;
+ Second : Integer;
+ Leap : Boolean;
+ Result : OS_Time;
+
+ begin
+ -- Input processing
+
+ Year := Year_Number (Year_Shift + tm_year);
+ Month := Month_Number (Month_Shift + tm_mon);
+ Day := Day_Number (tm_day);
+
+ -- Step 1: Validity checks of input values
+
+ if not Year'Valid
+ or else not Month'Valid
+ or else not Day'Valid
+ or else tm_hour not in 0 .. 24
+ or else tm_min not in 0 .. 59
+ or else tm_sec not in 0 .. 60
+ or else tm_isdst not in -1 .. 1
+ then
+ raise Time_Error;
+ end if;
+
+ -- Step 2: Potential leap second
+
+ if tm_sec = 60 then
+ Leap := True;
+ Second := 59;
+ else
+ Leap := False;
+ Second := tm_sec;
+ end if;
+
+ -- Step 3: Calculate the time value
+
+ Result :=
+ OS_Time
+ (Formatting_Operations.Time_Of
+ (Year => Year,
+ Month => Month,
+ Day => Day,
+ Day_Secs => 0.0, -- Time is given in h:m:s
+ Hour => tm_hour,
+ Minute => tm_min,
+ Second => Second,
+ Sub_Sec => 0.0, -- No precise sub second given
+ Leap_Sec => Leap,
+ Use_Day_Secs => False, -- Time is given in h:m:s
+ Is_Ada_05 => True, -- Force usage of explicit time zone
+ Time_Zone => 0)); -- Place the value in UTC
+ -- Step 4: Daylight Savings Time
+
+ if tm_isdst = 1 then
+ Result := Result + OS_Time (3_600) * Mili;
+ end if;
+
+ return Time (Result);
+ exception
+ when Constraint_Error =>
+ raise Time_Error;
+ end To_Ada_Time;
+
+ -----------------
+ -- To_Duration --
+ -----------------
+
+ function To_Duration
+ (tv_sec : Long_Integer;
+ tv_nsec : Long_Integer) return Duration
+ is
+ pragma Unsuppress (Overflow_Check);
+ begin
+ return Duration (tv_sec) + Duration (tv_nsec) / Mili_F;
+ end To_Duration;
+
+ ------------------------
+ -- To_Struct_Timespec --
+ ------------------------
+
+ procedure To_Struct_Timespec
+ (D : Duration;
+ tv_sec : out Long_Integer;
+ tv_nsec : out Long_Integer)
+ is
+ pragma Unsuppress (Overflow_Check);
+ Secs : Duration;
+ Nano_Secs : Duration;
+
+ begin
+ -- Seconds extraction, avoid potential rounding errors
+
+ Secs := D - 0.5;
+ tv_sec := Long_Integer (Secs);
+
+ -- 100 Nanoseconds extraction
+
+ Nano_Secs := D - Duration (tv_sec);
+ tv_nsec := Long_Integer (Nano_Secs * Mili);
+ end To_Struct_Timespec;
+
+ ------------------
+ -- To_Struct_Tm --
+ ------------------
+
+ procedure To_Struct_Tm
+ (T : Time;
+ tm_year : out Integer;
+ tm_mon : out Integer;
+ tm_day : out Integer;
+ tm_hour : out Integer;
+ tm_min : out Integer;
+ tm_sec : out Integer)
+ is
+ pragma Unsuppress (Overflow_Check);
+ Year : Year_Number;
+ Month : Month_Number;
+ Second : Integer;
+ Day_Secs : Day_Duration;
+ Sub_Sec : Duration;
+ Leap_Sec : Boolean;
+
+ begin
+ -- Step 1: Split the input time
+
+ Formatting_Operations.Split
+ (T, Year, Month, tm_day, Day_Secs,
+ tm_hour, tm_min, Second, Sub_Sec, Leap_Sec, True, 0);
+
+ -- Step 2: Correct the year and month
+
+ tm_year := Year - 1900;
+ tm_mon := Month - 1;
+
+ -- Step 3: Handle leap second occurrences
+
+ tm_sec := (if Leap_Sec then 60 else Second);
+ end To_Struct_Tm;
+
+ ------------------
+ -- To_Unix_Time --
+ ------------------
+
+ function To_Unix_Time (Ada_Time : Time) return Long_Integer is
+ pragma Unsuppress (Overflow_Check);
+ Ada_OS_Time : constant OS_Time := OS_Time (Ada_Time);
+ begin
+ return Long_Integer ((Ada_OS_Time - Epoch_Offset) / Mili);
+ exception
+ when Constraint_Error =>
+ raise Time_Error;
+ end To_Unix_Time;
+ end Conversion_Operations;
+
+ ---------------------------
-- Formatting_Operations --
---------------------------
Ada_Min_Year : constant := 1901;
Ada_Max_Year : constant := 2399;
- Mili_F : constant Duration := 10_000_000.0;
- Date_M : Time;
+ Date_M : OS_Time;
Elapsed_Leaps : Natural;
- Next_Leap_M : Time;
+ Next_Leap_M : OS_Time;
begin
- Date_M := Date;
+ Date_M := OS_Time (Date);
-- Step 1: Leap seconds processing
if Leap_Support then
Cumulative_Leap_Seconds
- (Start_Of_Time, Date, Elapsed_Leaps, Next_Leap_M);
+ (Start_Of_Time, Date_M, Elapsed_Leaps, Next_Leap_M);
Leap_Sec := Date_M >= Next_Leap_M;
Leap_Sec := False;
end if;
- Date_M := Date_M - Time (Elapsed_Leaps) * Mili;
+ Date_M := Date_M - OS_Time (Elapsed_Leaps) * Mili;
-- Step 2: Time zone processing
if Time_Zone /= 0 then
- Date_M := Date_M + Time (Time_Zone) * 60 * Mili;
+ Date_M := Date_M + OS_Time (Time_Zone) * 60 * Mili;
end if;
-- After the leap seconds and time zone have been accounted for,
-- Step 4: VMS system call
- Numtim (Status, Timbuf, Date_M);
+ Numtim (Status, Timbuf, Time (Date_M));
if Status mod 2 /= 1
or else Timbuf (1) not in Ada_Min_Year .. Ada_Max_Year
Minute : Integer;
Second : Integer;
Sub_Sec : Duration;
- Leap_Sec : Boolean;
- Use_Day_Secs : Boolean;
- Is_Ada_05 : Boolean;
- Time_Zone : Long_Integer) return Time
+ Leap_Sec : Boolean := False;
+ Use_Day_Secs : Boolean := False;
+ Is_Ada_05 : Boolean := False;
+ Time_Zone : Long_Integer := 0) return Time
is
procedure Cvt_Vectim
(Status : out Unsigned_Longword;
Status : Unsigned_Longword;
Timbuf : Unsigned_Word_Array (1 .. 7);
- Mili_F : constant := 10_000_000.0;
-
Y : Year_Number := Year;
Mo : Month_Number := Month;
D : Day_Number := Day;
Elapsed_Leaps : Natural;
Int_Day_Secs : Integer;
- Next_Leap_M : Time;
- Res_M : Time;
- Rounded_Res_M : Time;
+ Next_Leap_M : OS_Time;
+ Res : Time;
+ Res_M : OS_Time;
+ Rounded_Res_M : OS_Time;
begin
-- No validity checks are performed on the input values since it is
else
-- Sub second extraction
- if Day_Secs > 0.0 then
- Int_Day_Secs := Integer (Day_Secs - 0.5);
- else
- Int_Day_Secs := Integer (Day_Secs);
- end if;
+ Int_Day_Secs :=
+ (if Day_Secs > 0.0
+ then Integer (Day_Secs - 0.5)
+ else Integer (Day_Secs));
H := Int_Day_Secs / 3_600;
Mi := (Int_Day_Secs / 60) mod 60;
Timbuf (6) := Unsigned_Word (Se);
Timbuf (7) := 0;
- Cvt_Vectim (Status, Timbuf, Res_M);
+ Cvt_Vectim (Status, Timbuf, Res);
if Status mod 2 /= 1 then
raise Time_Error;
-- Step 3: Sub second adjustment
- Res_M := Res_M + Time (Su * Mili_F);
+ Res_M := OS_Time (Res) + OS_Time (Su * Mili_F);
-- Step 4: Bounds check
-- Step 5: Time zone processing
if Time_Zone /= 0 then
- Res_M := Res_M - Time (Time_Zone) * 60 * Mili;
+ Res_M := Res_M - OS_Time (Time_Zone) * 60 * Mili;
end if;
-- Step 6: Leap seconds processing
Cumulative_Leap_Seconds
(Start_Of_Time, Res_M, Elapsed_Leaps, Next_Leap_M);
- Res_M := Res_M + Time (Elapsed_Leaps) * Mili;
+ Res_M := Res_M + OS_Time (Elapsed_Leaps) * Mili;
-- An Ada 2005 caller requesting an explicit leap second or an
-- Ada 95 caller accounting for an invisible leap second.
if Leap_Sec
or else Res_M >= Next_Leap_M
then
- Res_M := Res_M + Time (1) * Mili;
+ Res_M := Res_M + OS_Time (1) * Mili;
end if;
-- Leap second validity check
end if;
end if;
- return Res_M;
+ return Time (Res_M);
end Time_Of;
end Formatting_Operations;
return get_gmtoff;
end UTC_Time_Offset;
end Time_Zones_Operations;
-
--- Start of elaboration code for Ada.Calendar
-
-begin
- -- Population of the leap seconds table
-
- if Leap_Support then
- declare
- type Leap_Second_Date is record
- Year : Year_Number;
- Month : Month_Number;
- Day : Day_Number;
- end record;
-
- Leap_Second_Dates :
- constant array (1 .. Leap_Seconds_Count) of Leap_Second_Date :=
- ((1972, 6, 30), (1972, 12, 31), (1973, 12, 31), (1974, 12, 31),
- (1975, 12, 31), (1976, 12, 31), (1977, 12, 31), (1978, 12, 31),
- (1979, 12, 31), (1981, 6, 30), (1982, 6, 30), (1983, 6, 30),
- (1985, 6, 30), (1987, 12, 31), (1989, 12, 31), (1990, 12, 31),
- (1992, 6, 30), (1993, 6, 30), (1994, 6, 30), (1995, 12, 31),
- (1997, 6, 30), (1998, 12, 31), (2005, 12, 31));
-
- Ada_Min_Year : constant Year_Number := Year_Number'First;
- Days_In_Four_Years : constant := 365 * 3 + 366;
- VMS_Days : constant := 10 * 366 + 32 * 365 + 45;
-
- Days : Natural;
- Leap : Leap_Second_Date;
- Years : Natural;
-
- begin
- for Index in 1 .. Leap_Seconds_Count loop
- Leap := Leap_Second_Dates (Index);
-
- -- Calculate the number of days from the start of Ada time until
- -- the current leap second occurence. Non-leap centenial years
- -- are not accounted for in these calculations since there are
- -- no leap seconds after 2100 yet.
-
- Years := Leap.Year - Ada_Min_Year;
- Days := (Years / 4) * Days_In_Four_Years;
- Years := Years mod 4;
-
- if Years = 1 then
- Days := Days + 365;
-
- elsif Years = 2 then
- Days := Days + 365 * 2;
-
- elsif Years = 3 then
- Days := Days + 365 * 3;
- end if;
-
- Days := Days + Cumulative_Days_Before_Month (Leap.Month);
-
- if Is_Leap (Leap.Year)
- and then Leap.Month > 2
- then
- Days := Days + 1;
- end if;
-
- -- Add the number of days since the start of VMS time till the
- -- start of Ada time.
-
- Days := Days + Leap.Day + VMS_Days;
-
- -- Index - 1 previous leap seconds are added to Time (Index)
-
- Leap_Second_Times (Index) :=
- (Time (Days) * Secs_In_Day + Time (Index - 1)) * Mili;
- end loop;
- end;
- end if;
end Ada.Calendar;
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