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private.h
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1 /* Private header for tzdb code. */
2 
3 #ifndef PRIVATE_H
4 
5 #define PRIVATE_H
6 
7 /*
8  * This file is in the public domain, so clarified as of
9  * 1996-06-05 by Arthur David Olson.
10  *
11  * IDENTIFICATION
12  * src/timezone/private.h
13  */
14 
15 /*
16  * This header is for use ONLY with the time conversion code.
17  * There is no guarantee that it will remain unchanged,
18  * or that it will remain at all.
19  * Do NOT copy it to any system include directory.
20  * Thank you!
21  */
22 
23 #include <limits.h> /* for CHAR_BIT et al. */
24 #include <sys/wait.h> /* for WIFEXITED and WEXITSTATUS */
25 #include <unistd.h> /* for F_OK and R_OK */
26 
27 #include "pgtime.h"
28 
29 /* This string was in the Factory zone through version 2016f. */
30 #define GRANDPARENTED "Local time zone must be set--see zic manual page"
31 
32 /*
33  * IANA has a bunch of HAVE_FOO #defines here, but in PG we want pretty
34  * much all of that to be done by PG's configure script.
35  */
36 
37 #ifndef ENOTSUP
38 #define ENOTSUP EINVAL
39 #endif
40 #ifndef EOVERFLOW
41 #define EOVERFLOW EINVAL
42 #endif
43 
44 /* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
45 #define is_digit(c) ((unsigned)(c) - '0' <= 9)
46 
47 /* PG doesn't currently rely on <inttypes.h>, so work around strtoimax() */
48 #undef strtoimax
49 #ifdef HAVE_STRTOLL
50 #define strtoimax strtoll
51 #else
52 #define strtoimax strtol
53 #endif
54 
55 
56 /*
57  * Finally, some convenience items.
58  */
59 
60 #define TYPE_BIT(type) (sizeof (type) * CHAR_BIT)
61 #define TYPE_SIGNED(type) (((type) -1) < 0)
62 #define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
63 
64 /*
65  * Max and min values of the integer type T, of which only the bottom
66  * B bits are used, and where the highest-order used bit is considered
67  * to be a sign bit if T is signed.
68  */
69 #define MAXVAL(t, b) \
70  ((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t))) \
71  - 1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
72 #define MINVAL(t, b) \
73  ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
74 
75 /* The extreme time values, assuming no padding. */
76 #define TIME_T_MIN MINVAL(pg_time_t, TYPE_BIT(pg_time_t))
77 #define TIME_T_MAX MAXVAL(pg_time_t, TYPE_BIT(pg_time_t))
78 
79 /*
80  * 302 / 1000 is log10(2.0) rounded up.
81  * Subtract one for the sign bit if the type is signed;
82  * add one for integer division truncation;
83  * add one more for a minus sign if the type is signed.
84  */
85 #define INT_STRLEN_MAXIMUM(type) \
86  ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
87  1 + TYPE_SIGNED(type))
88 
89 /*
90  * INITIALIZE(x)
91  */
92 #define INITIALIZE(x) ((x) = 0)
93 
94 #undef _
95 #define _(msgid) (msgid)
96 
97 /* Handy macros that are independent of tzfile implementation. */
98 
99 #define YEARSPERREPEAT 400 /* years before a Gregorian repeat */
100 
101 #define SECSPERMIN 60
102 #define MINSPERHOUR 60
103 #define HOURSPERDAY 24
104 #define DAYSPERWEEK 7
105 #define DAYSPERNYEAR 365
106 #define DAYSPERLYEAR 366
107 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
108 #define SECSPERDAY ((int32) SECSPERHOUR * HOURSPERDAY)
109 #define MONSPERYEAR 12
110 
111 #define TM_SUNDAY 0
112 #define TM_MONDAY 1
113 #define TM_TUESDAY 2
114 #define TM_WEDNESDAY 3
115 #define TM_THURSDAY 4
116 #define TM_FRIDAY 5
117 #define TM_SATURDAY 6
118 
119 #define TM_JANUARY 0
120 #define TM_FEBRUARY 1
121 #define TM_MARCH 2
122 #define TM_APRIL 3
123 #define TM_MAY 4
124 #define TM_JUNE 5
125 #define TM_JULY 6
126 #define TM_AUGUST 7
127 #define TM_SEPTEMBER 8
128 #define TM_OCTOBER 9
129 #define TM_NOVEMBER 10
130 #define TM_DECEMBER 11
131 
132 #define TM_YEAR_BASE 1900
133 
134 #define EPOCH_YEAR 1970
135 #define EPOCH_WDAY TM_THURSDAY
136 
137 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
138 
139 /*
140  * Since everything in isleap is modulo 400 (or a factor of 400), we know that
141  * isleap(y) == isleap(y % 400)
142  * and so
143  * isleap(a + b) == isleap((a + b) % 400)
144  * or
145  * isleap(a + b) == isleap(a % 400 + b % 400)
146  * This is true even if % means modulo rather than Fortran remainder
147  * (which is allowed by C89 but not by C99 or later).
148  * We use this to avoid addition overflow problems.
149  */
150 
151 #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
152 
153 
154 /*
155  * The Gregorian year averages 365.2425 days, which is 31556952 seconds.
156  */
157 
158 #define AVGSECSPERYEAR 31556952L
159 #define SECSPERREPEAT \
160  ((int64) YEARSPERREPEAT * (int64) AVGSECSPERYEAR)
161 #define SECSPERREPEAT_BITS 34 /* ceil(log2(SECSPERREPEAT)) */
162 
163 #endif /* !defined PRIVATE_H */