* Rationale
The question often comes up of how to use multiple time zones in C code.
If you're single-threaded, you can just use setenv() to manipulate $TZ.
toybox does this, for example. But that's not thread-safe in two
distinct ways: firstly, getenv() is not thread-safe with respect to
modifications to the environment (and between the way putenv() is
specified and the existence of environ, it's not obvious how to fully
fix that), and secondly the _caller_ needs to ensure that no other
threads are using tzset() or any function that behaves "as if" tzset()
was called (which is neither easy to determine nor easy to ensure).
This isn't a bigger problem because most of the time the right answer
is to stop pretending that libc is at all suitable for any i18n, and
switch to icu4c instead. (The NDK icu4c headers do not include ucal_*,
so this is not a realistic option for most applications.)
But what if you're somewhere in between? Like the rust chrono library,
for example? What then?
Currently their "least worst" option is to reinvent the entire wheel and
read our tzdata files. Which isn't a great solution for anyone, for
obvious maintainability reasons.
So it's probably time we broke the catch-22 here and joined NetBSD in
offering a less broken API than standard C has for the last 40 years.
Sure, any would-be caller will have to have a separate "is this
Android?" and even "is this API level >= 35?" path, but that will fix
itself sometime in the 2030s when developers can just assume "yes, it
is", whereas if we keep putting off exposing anything, this problem
never gets solved.
(No-one's bothered to try to implement the std::chrono::time_zone
functionality in libc++ yet, but they'll face a similar problem if/when
they do.)
* Implementation
The good news is that tzcode already implements these functions, so
there's relatively little here.
I've chosen not to expose `struct state` because `struct __timezone_t`
makes for clearer error messages, given that compiler diagnostics will
show the underlying type name (`struct __timezone_t*`) rather than the
typedef name (`timezone_t`) that's used in calling code.
I've moved us over to FreeBSD's wcsftime() rather than keep the OpenBSD
one building --- I've long wanted to only have one implementation here,
and FreeBSD is already doing the "convert back and forth, calling the
non-wide function in the middle" dance that I'd hoped to get round to
doing myself someday. This should mean that our strftime() and
wcsftime() behaviors can't easily diverge in future, plus macOS/iOS are
mostly FreeBSD, so any bugs will likely be interoperable with the other
major mobile operating system, so there's something nice for everyone
there!
The FreeBSD wcsftime() implementation includes a wcsftime_l()
implementation, so that's one stub we can remove. The flip side of that
is that it uses mbsrtowcs_l() and wcsrtombs_l() which we didn't
previously have. So expose those as aliases of mbsrtowcs() and
wcsrtombs().
Bug: https://github.com/chronotope/chrono/issues/499
Test: treehugger
Change-Id: Iee1b9d763ead15eef3d2c33666b3403b68940c3c
Upstream made a change similar to our %s change, so we don't need that
difference any more. (But they didn't seem interested in our GNU
extensions, even though they're sensible ones that just ensure symmetry
between strftime() and strptime().)
Bug: http://b/167569813
Test: treehugger
Change-Id: I1d86d69c87b51719f0583341fafa7802869cd37e
We still have local differences, but this minimizes (and documents) them.
Bug: http://b/167569813
Test: treehugger
Change-Id: Ib90e6ccc5ec1224e7ee89224a51b87fc48c9931f
Coming to C23 via WG14 N2630.
This one is a little interesting, because it actually changes existing
behavior. Previously "0b101" would be parsed as "0", "b", "101" by these
functions. I'm led to believe that glibc plans to actually have separate
versions of these functions for C23 and pre-C23, so callers can have the
behavior they (implicitly) specify by virtue of which -std= they compile
with. Android has never really done anything like that, and I'm pretty
sure app developers have more than enough to worry about with API levels
without having to deal with the cartesian product of API level and C
standard.
Therefore, my plan A is "if you're running on Android >= U, you get C23
behavior". My plan B in the (I think unlikely) event that that actually
causes trouble for anyone is "if you're _targeting_ Android >= U, you
get C23 behavior". I don't think we'd actually want to have two versions
of each of these functions under any circumstances --- that seems by far
the most confusing option.
Test: treehugger
Change-Id: I0bbb30315d3fabd306905ad1484361f5d8745935
Note that this is only a partial update; some other files have changes
upstream that aren't here, but they're changes that seem to require a
bit more thought, whereas these seem easy (and the base64.c and fputws.c
C2x compatibility changes were the motivation to sync right now).
Test: treehugger
Change-Id: I2f86708e25bcb9e779ecb6f9643b769cd4f83240
musl libc doesn't provide fts, but elfutils and libabigail need it.
Export bionic's fts as a staic library that can be linked into elfutils
and libabigail when compiling against musl.
fts uses recallocarray, which musl doesn't provide, so also include
recallocarray.c in libfts.a.
Requires minor tweaks to fts.c and a wrapper around fts.h to make them
compatible with musl, primarily by providing local definitions of macros
provided in bionic's sys/cdefs.h.
Bug: 190084016
Test: m libfts
Change-Id: Ifac9a59e7504c0c1f5f8a3a5bd3c19a13980b83c
They're both obsolescent in POSIX.1-2008, and you really shouldn't be
using them, but since we can't actually delete them...
This change makes them both obey $TMPDIR if set, and fall back to
/data/local/tmp otherwise. That's as good as we've managed for anything
else such as tmpfile(3).
Also add some tests.
Bug: http://b/174682340
Test: treehugger
Change-Id: Ieef99dcc2062f84b2b7cbae046787fdfe975e772
Similar to the musl strstr. This patch also increases test coverage for
memmem, again similar to the strstr tests.
Test: treehugger
Change-Id: I7f4a2ab93a610cb692994d06d2512976e657ae9f
Even with formatting off, clang still tries to rearrange the include
files or the using statements, so disable that too.
Test: Verified that the include directories are not rearranged.
Change-Id: I991a1b2bfa94a8202c5a486664658d654f1c7811
Use the .clang-format-2 found in system/core instead of this which is
not actually being used.
Also, enable clang-format running by default.
All upstream directories are marked as ignoring formatting so that
their source files are not modified.
Test: NA
Change-Id: Icee6030f373fa5f072df162f97e6f34320e3d89a
As it turns out, our "generic" arm64 implementations of certain string.h
functions are not actually generic, since they will eagerly read memory
possibly outside of the bounds of an MTE granule, which may lead to a segfault
on MTE-enabled hardware. Therefore, move the implementations into a "default"
directory and use ifuncs to select between them and a new set of "mte"
implementations, conditional on whether the hardware and kernel support MTE.
The MTE implementations are currently naive implementations written in C
but will later be replaced with a set of optimized assembly implementations.
Bug: 135772972
Change-Id: Ife37c4e0e6fd60ff20a34594cc09c541af4d1dd7
The tables in the BSD tolower/toupper are slower for ASCII than just
doing the bit twiddling.
We can't actually remove the tables on LP32, so move them into the
"cruft" we keep around for backwards compatibility (but remove them for
LP64 where they were never exposed).
I noticed that the new bit-twiddling tolower(3) was performing better
on arm64 than toupper(3). The 0xdf constant was requiring an extra MOV,
and there isn't a BIC that takes an immediate value. Since we've already
done the comparison to check that we're in the right range (where the
bit is always set), though, we can EOR 0x20 to get the same result as
the missing BIC 0x20 in just one instruction.
I've applied that same optimization to towupper(3) too.
Before:
BM_ctype_tolower_n 3.30 ns 3.30 ns 212353035
BM_ctype_tolower_y 3.31 ns 3.30 ns 211234204
BM_ctype_toupper_n 3.30 ns 3.29 ns 214161246
BM_ctype_toupper_y 3.29 ns 3.28 ns 207643473
BM_wctype_towupper_ascii_n 3.53 ns 3.53 ns 195944444
BM_wctype_towupper_ascii_y 3.48 ns 3.48 ns 199233248
After:
BM_ctype_tolower_n 2.93 ns 2.92 ns 242373703
BM_ctype_tolower_y 2.88 ns 2.87 ns 245365309
BM_ctype_toupper_n 2.93 ns 2.93 ns 243049353
BM_ctype_toupper_y 2.89 ns 2.89 ns 245072521
BM_wctype_towupper_ascii_n 3.34 ns 3.33 ns 212951912
BM_wctype_towupper_ascii_y 3.29 ns 3.29 ns 214651254
(Why do both the "y" and "n" variants speed up with the EOR
change? Because the compiler transforms the code so that we
unconditionally do the bit twiddling and then use CSEL to decide whether
or not to actually use the result.)
We also save 1028 bytes of data in the LP64 libc.so.
Test: ran the bionic benchmarks and tests
Change-Id: I7829339f8cb89a58efe539c2a01c51807413aa2d
NetBSD seems to be the least well maintained of our three BSD upstreams,
and it's already the one we use the least. Let's push a little further
in that direction...
Test: new smoke tests
Change-Id: Idfebd11794445fe14cbfa07177a7392a7b36a5e4
Originally a BSD extension, now in glibc too. We've used it internally
for a while.
(cherry-pick of e4b13f7e3ca68edfcc5faedc5e7d4e13c4e8edb9.)
Bug: http://b/112163459
Test: ran tests
Change-Id: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
Merged-In: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
We've copied & pasted these to too many places. And if we're going to
have another go at upstreaming these, that's probably yet another reason
to have the *values* in just one place. (Even if upstream wants different
names, we'll likely keep the legacy names around for a while for source
compatibility.)
Bug: http://b/111903542
Test: ran tests
Change-Id: I8ccc557453d69530e5b74f865cbe0b458c84e3ba
pclose(3) is now an alias for fclose(3). We could add a FORTIFY check
that you use pclose(3) if and only if you used popen(3), but there seems
little value to that when we can just do the right thing.
This patch also adds the missing locking to _fwalk --- we need to lock
both the global list of FILE*s and also each FILE* we touch. POSIX says
that "The popen() function shall ensure that any streams from previous
popen() calls that remain open in the parent process are closed in the
new child process", which we implement via _fwalk(fclose) in the child,
but we might want to just make *all* popen(3) file descriptors O_CLOEXEC
in all cases.
Ignore fewer errors in popen(3) failure cases.
Improve popen(3) test coverage.
Bug: http://b/72470344
Test: ran tests
Change-Id: Ic937594bf28ec88b375f7e5825b9c05f500af438
We saw crashes from pthread_exit+debuggerd on LP32
(https://issuetracker.google.com/72291624), and it seems like the
equivalent problem should exist with system(3). I fixed posix_spawn(3)
as part of that bug, so the easiest fix is probably to reuse that.
Bug: http://b/72470344
Test: ran tests
Change-Id: I05f838706f2b4a14ac3ee21292833e6c8579b0d4
Now that we have a clang that supports transparent overloads, we can
kill all of this cruft, and restore our upstream sources to their
untouched glory. Woohoo!
Bug: 12231437
Test: Built aosp_marlin; no obvious patch-related aosp_mips issues.
Change-Id: I520a19d014f12137f80e43f973dccd6711c571cd
This is also slightly faster for the no VDSO case (56ns vs 66ns).
Bug: N/A
Test: ran tests, benchmarks
Change-Id: I2b0edd06ee6942eb57c32678279278a53ca5ee9b
There are no meaningful changes here, just a minimal conversion to two
C++ templates to make further changes easier.
Bug: N/A
Test: ran tests, benchmarks
Change-Id: I958fbf17a85f19dd8f17bfb4bbb9314d220daa3b
Also simplify trivial one-liners like perror/puts/fputs, and clean up
fread/fwrite slightly.
Fix perror to match POSIX.
Add basic perror and *_unlocked tests.
Bug: N/A
Test: ran tests
Change-Id: I63f83c8e0c15c3c4096509d17421ac331b6fc23d
iOS 10 has <sys/random.h> with getentropy, glibc >= 2.25 has
<sys/random.h> with getentropy and getrandom. (glibc also pollutes
<unistd.h>, but that seems like a bad idea.)
Also, all supported devices now have kernels with the getrandom system
call.
We've had these available internally for a while, but it seems like the
time is ripe to expose them.
Bug: http://b/67014255
Test: ran tests
Change-Id: I76dde1e3a2d0bc82777eea437ac193f96964f138
(Where errno is relevant.)
Also consistently use -1 as the fd for anonymous mmaps. (It doesn't matter,
but it's more common, and potentially more intention-revealing.)
Bug: http://b/65608572
Test: ran tests
Change-Id: Ie9a207632d8242f42086ba3ca862519014c3c102
Library calls like system() and popen() invoke the shell executable
pointed to by '_PATH_BSHELL' in order to run the command passed into the
function. The _PATH_BSHELL points to /system/bin/sh by default and thus
breaks any vendor process trying to use system() / popen(), as they are
denied access to system shell by selinux.
This CL make necessary changes, so the implmentations of system() and popen()
can use the appropriate shell (e.g. /vendor/bin/sh for processes running
out of /vendor partition). Also, changes the implementation of system()
and popen().
Bug: 64832610
Test: Manual, Using a test program running from /system/bin and
/vendor/bin to ensure correct shell is being used.
Change-Id: Ie7168d69decb1ae98284446ae7db34dec930dc33
Merged-In: Ie7168d69decb1ae98284446ae7db34dec930dc33
Signed-off-by: Sandeep Patil <sspatil@google.com>
(cherry picked from commit aa3e32422c)
Almost all of our w* functions come from FreeBSD already. The one downside is
that we can't take all our w* functions from FreeBSD because FreeBSD handles
locales very differently from us.
Bug: N/A
Test: ran tests
Change-Id: I177b4332499992babd5d5afe5b3f469f8c4345a5
Upstream's killpg is diverging further from glibc behavior, so let's just fork.
Bug: N/A
Test: ran tests
Change-Id: I70a3543018bc0a5c0bbf019ac527043b90568fda
__isthreaded is annoying for ARC++ and useless for everyone. Just hard-code
the value in ndk_cruft for LP32 and be done with it.
Bug: N/A
Test: builds
Change-Id: I08f11a404bbec55ed57cb1e18b5116163c7d7d13
This library is used by a number of different libraries in the system.
Make it easy for platform libraries to use this library and create
an actual exported include file.
Change the names of the functions to reflect the new name of the library.
Run clang_format on the async_safe_log.cpp file since the formatting is
all over the place.
Bug: 31919199
Test: Compiled for angler/bullhead, and booted.
Test: Ran bionic unit tests.
Test: Ran the malloc debug tests.
Change-Id: I8071bf690c17b0ea3bc8dc5749cdd5b6ad58478a
