1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--              A D A . C A L E N D A R . C O N V E R S I O N S             --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 2008-2014, Free Software Foundation, Inc.         --
10--                                                                          --
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.                                     --
17--                                                                          --
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.               --
21--                                                                          --
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/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package provides various routines for conversion between Ada and Unix
33--  time models - Time, Duration, struct tm and struct timespec.
34
35with Interfaces.C;
36
37package Ada.Calendar.Conversions is
38
39   function To_Ada_Time (Unix_Time : Interfaces.C.long) return Time;
40   --  Convert a time value represented as number of seconds since the
41   --  Unix Epoch to a time value relative to an Ada implementation-defined
42   --  Epoch. The units of the result are nanoseconds on all targets. Raises
43   --  Time_Error if the result cannot fit into a Time value.
44
45   function To_Ada_Time
46     (tm_year  : Interfaces.C.int;
47      tm_mon   : Interfaces.C.int;
48      tm_day   : Interfaces.C.int;
49      tm_hour  : Interfaces.C.int;
50      tm_min   : Interfaces.C.int;
51      tm_sec   : Interfaces.C.int;
52      tm_isdst : Interfaces.C.int) return Time;
53   --  Convert a time value expressed in Unix-like fields of struct tm into
54   --  a Time value relative to the Ada Epoch. The ranges of the formals are
55   --  as follows:
56
57   --     tm_year   --  years since 1900
58   --     tm_mon    --  months since January [0 .. 11]
59   --     tm_day    --  day of the month [1 .. 31]
60   --     tm_hour   --  hours since midnight [0 .. 24]
61   --     tm_min    --  minutes after the hour [0 .. 59]
62   --     tm_sec    --  seconds after the minute [0 .. 60]
63   --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
64
65   --  The returned value is in UTC and may or may not contain leap seconds
66   --  depending on whether binder flag "-y" was used. Raises Time_Error if
67   --  the input values are out of the defined ranges or if tm_sec equals 60
68   --  and the instance in time is not a leap second occurrence.
69
70   function To_Duration
71     (tv_sec  : Interfaces.C.long;
72      tv_nsec : Interfaces.C.long) return Duration;
73   --  Convert an elapsed time value expressed in Unix-like fields of struct
74   --  timespec into a Duration value. The expected ranges are:
75
76   --     tv_sec   -  seconds
77   --     tv_nsec  -  nanoseconds
78
79   procedure To_Struct_Timespec
80     (D       : Duration;
81      tv_sec  : out Interfaces.C.long;
82      tv_nsec : out Interfaces.C.long);
83   --  Convert a Duration value into the constituents of struct timespec.
84   --  Formal tv_sec denotes seconds and tv_nsecs denotes nanoseconds.
85
86   procedure To_Struct_Tm
87     (T       : Time;
88      tm_year : out Interfaces.C.int;
89      tm_mon  : out Interfaces.C.int;
90      tm_day  : out Interfaces.C.int;
91      tm_hour : out Interfaces.C.int;
92      tm_min  : out Interfaces.C.int;
93      tm_sec  : out Interfaces.C.int);
94   --  Convert a Time value set in the Ada Epoch into the constituents of
95   --  struct tm. The ranges of the out formals are as follows:
96
97   --     tm_year   --  years since 1900
98   --     tm_mon    --  months since January [0 .. 11]
99   --     tm_day    --  day of the month [1 .. 31]
100   --     tm_hour   --  hours since midnight [0 .. 24]
101   --     tm_min    --  minutes after the hour [0 .. 59]
102   --     tm_sec    --  seconds after the minute [0 .. 60]
103   --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
104
105   --  The input date is considered to be in UTC
106
107   function To_Unix_Time (Ada_Time : Time) return Interfaces.C.long;
108   --  Convert a time value represented as number of time units since the Ada
109   --  implementation-defined Epoch to a value relative to the Unix Epoch. The
110   --  units of the result are seconds. Raises Time_Error if the result cannot
111   --  fit into a Time value.
112
113end Ada.Calendar.Conversions;
114