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author | Paul Eggert <eggert@cs.ucla.edu> | 2005-03-09 19:23:05 +0000 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2005-03-09 19:23:05 +0000 |
commit | 5fd82cbf0d0b696dcb961b3b99a44699ae1d654b (patch) | |
tree | 8cde482286c04356315a95f1cca16b4faa3df72b /lib | |
parent | 064157578c80e06e830fa100862ff075cd0c7365 (diff) | |
download | coreutils-5fd82cbf0d0b696dcb961b3b99a44699ae1d654b.tar.xz |
(TYPE_IS_INTEGER, TYPE_TWOS_COMPLEMENT): New macros,
for consistency with intprops.h.
(time_t_is_integer, twos_complement_arithmetic): Use them.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/mktime.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/lib/mktime.c b/lib/mktime.c index 16f5b9a5a..9a92cb008 100644 --- a/lib/mktime.c +++ b/lib/mktime.c @@ -1,5 +1,6 @@ /* Convert a `struct tm' to a time_t value. - Copyright (C) 1993-1999, 2002, 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 1993-1999, 2002, 2003, 2004, 2005 Free Software Foundation, + Inc. This file is part of the GNU C Library. Contributed by Paul Eggert (eggert@twinsun.com). @@ -60,10 +61,25 @@ ? (a) >> (b) \ : (a) / (1 << (b)) - ((a) % (1 << (b)) < 0)) -/* The extra casts work around common compiler bugs. */ +/* The extra casts in the following macros work around compiler bugs, + e.g., in Cray C 5.0.3.0. */ + +/* True if the arithmetic type T is an integer type. bool counts as + an integer. */ +#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) + +/* True if negative values of the integer type T use twos complement + representation. */ +#define TYPE_TWOS_COMPLEMENT(t) ((t) - (t) 1 == (t) ((t) ~ (t) 1 + (t) 1)) + +/* True if the arithmetic type T is signed. */ #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) -/* The outer cast is needed to work around a bug in Cray C 5.0.3.0. - It is necessary at least when t == time_t. */ + +/* The maximum and minimum values for the integer type T. These + macros have undefined behavior if T is signed and has padding bits + (i.e., bits that do not contribute to the value), or if T uses + signed-magnitude representation. If this is a problem for you, + please let us know how to fix it for your host. */ #define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \ ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) #define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t))) @@ -79,8 +95,8 @@ /* Verify a requirement at compile-time (unlike assert, which is runtime). */ #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; } -verify (time_t_is_integer, (time_t) 0.5 == 0); -verify (twos_complement_arithmetic, -1 == ~1 + 1); +verify (time_t_is_integer, TYPE_IS_INTEGER (time_t)); +verify (twos_complement_arithmetic, TYPE_TWOS_COMPLEMENT (int)); /* The code also assumes that signed integer overflow silently wraps around, but this assumption can't be stated without causing a diagnostic on some hosts. */ |