This costs us about 1000 fewer syscalls, which makes "adb shell strace date"
a lot more readable (which is the reason I've been meaning to fix this for a
long time now), but also actually saves a measurable amount of time.
Longer-term we should try to keep the tzdata mmap(2)ed in like libcore
does.
Change-Id: I1dd9c81968a13d3a6a55ba17f8a7d5c1f38cd103
libc/tzcode/localtime.c: In function 'differ_by_repeat':
libc/tzcode/localtime.c:338:2: error: comparison is always false due to limited range of data type [-Werror=type-limits]
Change-Id: Ic84be6391a66e9d50ed98f41d865387c77a60ffa
localtime.c and strftime.c are still quite different from upstream because of
our extensions, but the other files continue to be identical, and the two
exceptions should be otherwise identical.
From the tzcode2013e release notes:
Changes affecting Godthab time stamps after 2037 if version mismatch
Allow POSIX-like TZ strings where the transition time's hour can
range from -167 through 167, instead of the POSIX-required 0
through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
new Fiji rules. This is a more-compact way to represent
far-future time stamps for America/Godthab, America/Santiago,
Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
this change. (Derived from a suggestion by Arthur David Olson.)
Allow POSIX-like TZ strings where daylight saving time is in
effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
Argentina Summer Time all year. This supports a more-compact way
to represent the 2013d data for America/Argentina/San_Luis.
Because of the change for San Luis noted above this change does not
affect the current data. (Thanks to Andrew Main (Zefram) for
suggestions that improved this change.)
Where these two TZ changes take effect, there is a minor extension
to the tz file format in that it allows new values for the
embedded TZ-format string, and the tz file format version number
has therefore been increased from 2 to 3 as a precaution.
Version-2-based client code should continue to work as before for
all time stamps before 2038. Existing version-2-based client code
(tzcode, GNU/Linux, Solaris) has been tested on version-3-format
files, and typically works in practice even for time stamps after
2037; the only known exception is America/Godthab.
Changes affecting API
Support for floating-point time_t has been removed.
It was always dicey, and POSIX no longer requires it.
(Thanks to Eric Blake for suggesting to the POSIX committee to
remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
Heninger, Arthur David Olson, and Alois Treindl, for reporting
bugs and elucidating some of the corners of the old floating-point
implementation.)
The signatures of 'offtime', 'timeoff', and 'gtime' have been
changed back to the old practice of using 'long' to represent UT
offsets. This had been inadvertently and mistakenly changed to
'int_fast32_t'. (Thanks to Christos Zoulos.)
The code avoids undefined behavior on integer overflow in some
more places, including gmtime, localtime, mktime and zdump.
Changes affecting code internals
Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
Changes affecting documentation and commentary
Documentation and commentary is more careful to distinguish UT in
general from UTC in particular. (Thanks to Steve Allen.)
From the tzcode2013f release notes:
Changes affecting API
The types of the global variables 'timezone' and 'altzone' (if present)
have been changed back to 'long'. This is required for 'timezone'
by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
These variables were originally 'long' in the tz code, but were
mistakenly changed to 'time_t' in 1987; nobody reported the
incompatibility until now. The difference matters on x32, where
'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
Change-Id: I14937c42a391ddb865e4d89f0783961bcc6baa21
Well, kinda... localtime.c still contains a bunch of Android-specific
hacks, as does strftime.c. But the other files are now exactly the same
as upstream.
This catches up with several years of bug fixes, and fixes most of the
compiler warnings that were in this code. (Just two remain.)
Bug: 1744909
Change-Id: I2ddfecb6fd408c847397c17afb0fff859e27feef
In the old code, the index was a file to itself, so it made sense to
read until you hit the end of the file. In the new code, the index is
followed by hundreds of KiB of data, so we need to just search the
index.
Bug: 8368791
Change-Id: Icf5f8b5516cf3a93679fa849c9f6cd1cb100e0f1
Normally, the C library implicitly caches your timezone by virtue
of the fact that the prehistoric API assumes a single timezone for
the entire process.
The unfortunate mktime_tz and localtime_tz extensions work around
this, but represent timezones as strings to their callers, so code
that makes heavy use of these needs a cache to be able to perform
acceptably until it can hopefully one day be rewritten to use
java.util.Calendar or icu4c.
Bug: 8270865
Change-Id: I92e3964e86dc33ceac925f819cc5e26ff4203f50
Also add missing declarations to misc. functions.
Fix clearerr() implementation (previous was broken).
Handle feature test macros like _POSIX_C_SOURCE properly.
Change-Id: Icdc973a6b9d550a166fc2545f727ea837fe800c4
The problem is that time_t is signed, and the original code relied on the
fact that (X + c < X) in case of overflow for c >= 0. Unfortunately, this
condition is only guaranteed by the standard for unsigned arithmetic, and
the gcc 4.4.0 optimizer did completely remove the corresponding test from
the code. This resulted in a missing boundary check, and an infinite loop.
The problem is solved by testing explicitely for TIME_T_MIN and TIME_T_MAX
in the loop that uses this.
Also fix increment_overflow and long_increment_overflow which were buggy
for exactly the same reasons.
Note: a similar fix is needed for system/core/libcutils
