1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . C A L E N D A R --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
22 -- As a special exception under Section 7 of GPL version 3, you are granted --
23 -- additional permissions described in the GCC Runtime Library Exception, --
24 -- version 3.1, as published by the Free Software Foundation. --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
34 ------------------------------------------------------------------------------
36 -- This is the OpenVMS version
38 with System
.OS_Primitives
;
40 package Ada
.Calendar
is
44 -- Declarations representing limits of allowed local time values. Note that
45 -- these do NOT constrain the possible stored values of time which may well
46 -- permit a larger range of times (this is explicitly allowed in Ada 95).
48 subtype Year_Number
is Integer range 1901 .. 2399;
49 subtype Month_Number
is Integer range 1 .. 12;
50 subtype Day_Number
is Integer range 1 .. 31;
52 subtype Day_Duration
is Duration range 0.0 .. 86_400
.0
;
53 -- Note that a value of 86_400.0 is the start of the next day
55 function Clock
return Time
;
56 -- The returned time value is the number of nanoseconds since the start
57 -- of Ada time (1901-01-01 00:00:00.0 UTC). If leap seconds are enabled,
58 -- the result will contain all elapsed leap seconds since the start of
59 -- Ada time until now.
61 function Year
(Date
: Time
) return Year_Number
;
62 function Month
(Date
: Time
) return Month_Number
;
63 function Day
(Date
: Time
) return Day_Number
;
64 function Seconds
(Date
: Time
) return Day_Duration
;
68 Year
: out Year_Number
;
69 Month
: out Month_Number
;
71 Seconds
: out Day_Duration
);
72 -- Break down a time value into its date components set in the current
73 -- time zone. If Split is called on a time value created using Ada 2005
74 -- Time_Of in some arbitrary time zone, the input value will always be
75 -- interpreted as relative to the local time zone.
81 Seconds
: Day_Duration
:= 0.0) return Time
;
82 -- GNAT Note: Normally when procedure Split is called on a Time value
83 -- result of a call to function Time_Of, the out parameters of procedure
84 -- Split are identical to the in parameters of function Time_Of. However,
85 -- when a non-existent time of day is specified, the values for Seconds
86 -- may or may not be different. This may happen when Daylight Saving Time
87 -- (DST) is in effect, on the day when switching to DST, if Seconds
88 -- specifies a time of day in the hour that does not exist. For example,
91 -- Time_Of (Year => 1998, Month => 4, Day => 5, Seconds => 10740.0)
93 -- will return a Time value T. If Split is called on T, the resulting
94 -- Seconds may be 14340.0 (3:59:00) instead of 10740.0 (2:59:00 being
95 -- a time that not exist).
97 function "+" (Left
: Time
; Right
: Duration) return Time
;
98 function "+" (Left
: Duration; Right
: Time
) return Time
;
99 function "-" (Left
: Time
; Right
: Duration) return Time
;
100 function "-" (Left
: Time
; Right
: Time
) return Duration;
101 -- The first three functions will raise Time_Error if the resulting time
102 -- value is less than the start of Ada time in UTC or greater than the
103 -- end of Ada time in UTC. The last function will raise Time_Error if the
104 -- resulting difference cannot fit into a duration value.
106 function "<" (Left
, Right
: Time
) return Boolean;
107 function "<=" (Left
, Right
: Time
) return Boolean;
108 function ">" (Left
, Right
: Time
) return Boolean;
109 function ">=" (Left
, Right
: Time
) return Boolean;
111 Time_Error
: exception;
114 pragma Inline
(Clock
);
116 pragma Inline
(Year
);
117 pragma Inline
(Month
);
124 pragma Inline
("<=");
126 pragma Inline
(">=");
128 -- Although the units are 100 nanoseconds, for the purpose of better
129 -- readability, this unit will be called "mili".
131 Mili
: constant := 10_000_000
;
132 Mili_F
: constant := 10_000_000
.0
;
133 Milis_In_Day
: constant := 864_000_000_000
;
134 Secs_In_Day
: constant := 86_400
;
136 -- Time is represented as the number of 100-nanosecond (ns) units from the
137 -- system base date and time 1858-11-17 0.0 (the Smithsonian base date and
138 -- time for the astronomic calendar).
140 -- The time value stored is typically a UTC value, as provided in standard
141 -- Unix environments. If this is the case then Split and Time_Of perform
142 -- required conversions to and from local times.
144 -- Notwithstanding this definition, Time is not quite the same as OS_Time.
145 -- Relative Time is positive, whereas relative OS_Time is negative,
146 -- but this declaration makes for easier conversion.
148 type Time
is new System
.OS_Primitives
.OS_Time
;
150 Days_In_Month
: constant array (Month_Number
) of Day_Number
:=
151 (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
152 -- Days in month for non-leap year, leap year case is adjusted in code
154 Invalid_Time_Zone_Offset
: Long_Integer;
155 pragma Import
(C
, Invalid_Time_Zone_Offset
, "__gnat_invalid_tzoff");
157 function Is_Leap
(Year
: Year_Number
) return Boolean;
158 -- Determine whether a given year is leap
160 ----------------------------------------------------------
161 -- Target-Independent Interface to Children of Calendar --
162 ----------------------------------------------------------
164 -- The following packages provide a target-independent interface to the
165 -- children of Calendar - Arithmetic, Conversions, Delays, Formatting and
168 -- NOTE: Delays does not need a target independent interface because
169 -- VMS already has a target specific file for that package.
171 ---------------------------
172 -- Arithmetic_Operations --
173 ---------------------------
175 package Arithmetic_Operations
is
177 function Add
(Date
: Time
; Days
: Long_Integer) return Time
;
178 -- Add a certain number of days to a time value
183 Days
: out Long_Integer;
184 Seconds
: out Duration;
185 Leap_Seconds
: out Integer);
186 -- Calculate the difference between two time values in terms of days,
187 -- seconds and leap seconds elapsed. The leap seconds are not included
188 -- in the seconds returned. If Left is greater than Right, the returned
189 -- values are positive, negative otherwise.
191 function Subtract
(Date
: Time
; Days
: Long_Integer) return Time
;
192 -- Subtract a certain number of days from a time value
194 end Arithmetic_Operations
;
196 ---------------------------
197 -- Conversion_Operations --
198 ---------------------------
200 package Conversion_Operations
is
202 function To_Ada_Time
(Unix_Time
: Long_Integer) return Time
;
203 -- Unix to Ada Epoch conversion
212 tm_isdst
: Integer) return Time
;
213 -- Struct tm to Ada Epoch conversion
216 (tv_sec
: Long_Integer;
217 tv_nsec
: Long_Integer) return Duration;
218 -- Struct timespec to Duration conversion
220 procedure To_Struct_Timespec
222 tv_sec
: out Long_Integer;
223 tv_nsec
: out Long_Integer);
224 -- Duration to struct timespec conversion
226 procedure To_Struct_Tm
228 tm_year
: out Integer;
229 tm_mon
: out Integer;
230 tm_day
: out Integer;
231 tm_hour
: out Integer;
232 tm_min
: out Integer;
233 tm_sec
: out Integer);
234 -- Time to struct tm conversion
236 function To_Unix_Time
(Ada_Time
: Time
) return Long_Integer;
237 -- Ada to Unix Epoch conversion
239 end Conversion_Operations
;
241 ---------------------------
242 -- Formatting_Operations --
243 ---------------------------
245 package Formatting_Operations
is
247 function Day_Of_Week
(Date
: Time
) return Integer;
248 -- Determine which day of week Date falls on. The returned values are
249 -- within the range of 0 .. 6 (Monday .. Sunday).
253 Year
: out Year_Number
;
254 Month
: out Month_Number
;
255 Day
: out Day_Number
;
256 Day_Secs
: out Day_Duration
;
258 Minute
: out Integer;
259 Second
: out Integer;
260 Sub_Sec
: out Duration;
261 Leap_Sec
: out Boolean;
263 Is_Historic
: Boolean;
264 Time_Zone
: Long_Integer);
265 pragma Export
(Ada
, Split
, "__gnat_split");
266 -- Split a time value into its components. If flag Is_Historic is set,
267 -- this routine would try to use to the best of the OS's abilities the
268 -- time zone offset that was or will be in effect on Date. Set Use_TZ
269 -- to use the local time zone (the value in Time_Zone is ignored) when
270 -- splitting a time value.
274 Month
: Month_Number
;
276 Day_Secs
: Day_Duration
;
282 Use_Day_Secs
: Boolean;
284 Is_Historic
: Boolean;
285 Time_Zone
: Long_Integer) return Time
;
286 pragma Export
(Ada
, Time_Of
, "__gnat_time_of");
287 -- Given all the components of a date, return the corresponding time
288 -- value. Set Use_Day_Secs to use the value in Day_Secs, otherwise the
289 -- day duration will be calculated from Hour, Minute, Second and Sub_
290 -- Sec. If flag Is_Historic is set, this routine would try to use to the
291 -- best of the OS's abilities the time zone offset that was or will be
292 -- in effect on the input date. Set Use_TZ to use the local time zone
293 -- (the value in formal Time_Zone is ignored) when building a time value
294 -- and to verify the validity of a requested leap second.
296 end Formatting_Operations
;
298 ---------------------------
299 -- Time_Zones_Operations --
300 ---------------------------
302 package Time_Zones_Operations
is
304 function UTC_Time_Offset
(Date
: Time
) return Long_Integer;
305 -- Return (in seconds) the difference between the local time zone and
306 -- UTC time at a specific historic date.
308 end Time_Zones_Operations
;