gcc/ada/a-calcon.ads

   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, 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 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  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.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package provides various routines for conversion between Ada and Unix
  35 --  time models - Time, Duration, struct tm and struct timespec.
  36
  37 with Interfaces.C;
  38
  39 package Ada.Calendar.Conversions is
  40
  41    function To_Ada_Time (Unix_Time : Interfaces.C.long) return Time;
  42    --  Convert a time value represented as number of seconds since the Unix
  43    --  Epoch to a time value relative to an Ada implementation-defined Epoch.
  44    --  The units of the result are 100 nanoseconds on VMS and nanoseconds on
  45    --  all other targets. Raises Time_Error if the result cannot fit into a
  46    --  Time value.
  47
  48    function To_Ada_Time
  49      (tm_year  : Interfaces.C.int;
  50       tm_mon   : Interfaces.C.int;
  51       tm_day   : Interfaces.C.int;
  52       tm_hour  : Interfaces.C.int;
  53       tm_min   : Interfaces.C.int;
  54       tm_sec   : Interfaces.C.int;
  55       tm_isdst : Interfaces.C.int) return Time;
  56    --  Convert a time value expressed in Unix-like fields of struct tm into
  57    --  a Time value relative to the Ada Epoch. The ranges of the formals are
  58    --  as follows:
  59
  60    --     tm_year   --  years since 1900
  61    --     tm_mon    --  months since January [0 .. 11]
  62    --     tm_day    --  day of the month [1 .. 31]
  63    --     tm_hour   --  hours since midnight [0 .. 24]
  64    --     tm_min    --  minutes after the hour [0 .. 59]
  65    --     tm_sec    --  seconds after the minute [0 .. 60]
  66    --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
  67
  68    --  The returned value is in UTC and may or may not contain leap seconds
  69    --  depending on whether binder flag "-y" was used. Raises Time_Error if
  70    --  the input values are out of the defined ranges or if tm_sec equals 60
  71    --  and the instance in time is not a leap second occurrence.
  72
  73    function To_Duration
  74      (tv_sec  : Interfaces.C.long;
  75       tv_nsec : Interfaces.C.long) return Duration;
  76    --  Convert an elapsed time value expressed in Unix-like fields of struct
  77    --  timespec into a Duration value. The expected ranges are:
  78
  79    --     tv_sec   -  seconds
  80    --     tv_nsec  -  nanoseconds
  81
  82    procedure To_Struct_Timespec
  83      (D       : Duration;
  84       tv_sec  : out Interfaces.C.long;
  85       tv_nsec : out Interfaces.C.long);
  86    --  Convert a Duration value into the constituents of struct timespec.
  87    --  Formal tv_sec denotes seconds and tv_nsecs denotes nanoseconds.
  88
  89    procedure To_Struct_Tm
  90      (T       : Time;
  91       tm_year : out Interfaces.C.int;
  92       tm_mon  : out Interfaces.C.int;
  93       tm_day  : out Interfaces.C.int;
  94       tm_hour : out Interfaces.C.int;
  95       tm_min  : out Interfaces.C.int;
  96       tm_sec  : out Interfaces.C.int);
  97    --  Convert a Time value set in the Ada Epoch into the constituents of
  98    --  struct tm. The ranges of the out formals are as follows:
  99
 100    --     tm_year   --  years since 1900
 101    --     tm_mon    --  months since January [0 .. 11]
 102    --     tm_day    --  day of the month [1 .. 31]
 103    --     tm_hour   --  hours since midnight [0 .. 24]
 104    --     tm_min    --  minutes after the hour [0 .. 59]
 105    --     tm_sec    --  seconds after the minute [0 .. 60]
 106    --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
 107
 108    --  The input date is considered to be in UTC
 109
 110    function To_Unix_Time (Ada_Time : Time) return Interfaces.C.long;
 111    --  Convert a time value represented as number of time units since the Ada
 112    --  implementation-defined Epoch to a value relative to the Unix Epoch. The
 113    --  units of the result are seconds. Raises Time_Error if the result cannot
 114    --  fit into a Time value.
 115
 116 end Ada.Calendar.Conversions;