* 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
Add vector version mem* and str* functions and only build them when the
vector extension is enabled.
The original implementation comes from
https://github.com/sifive/sifive-libc, which we agree to contribute to
the Android Open Source Project.
Test: mma
Change-Id: I11b671a5bc571d7c783a657f272f282df7d16c29
Signed-off-by: Yun Hsiang <yun.hsiang@sifive.com>
Now <utmpx.h> isn't any more useful on Android than <utmp.h> is, but it
is POSIX, and -- importantly -- we can implement it with just a header
file, so code can use it on every existing API level.
macOS does indeed only have the <utmpx.h> functions (although it does
still have the <utmp.h> header!), so potentially portable code might
want <utmpx.h> on Android. (glibc/musl both have both headers.)
Bug: https://github.com/landley/toybox/pull/213
Test: treehugger
Change-Id: Iaa88167708182009a63e2e1a15f11186b251ed02
The next NDK to take these headers only supports API 21 and later, so
clean up some of the trivial cruft.
Test: treehugger
Change-Id: Ib735a776d244cc82858f2ed629dd63a54dbaf650
We still have local differences, but this minimizes (and documents) them.
Bug: http://b/167569813
Test: treehugger
Change-Id: Ib90e6ccc5ec1224e7ee89224a51b87fc48c9931f
This one's a bit simpler, because there is only one upstream memset()
implementation.
Test: treehugger
Change-Id: I2536d0eb72adaacfa6a0e40d2bd29fc833988c16
Outsource this to them, and choose the best of the two options available
based on the hardware we're running on.
Test: treehugger
Change-Id: I2fa7555c971b64a6decca132210e901ffa248efa
Pull the portable C string functions from FreeBSD, and do fairly literal
translations of our existing .S files for the bionic-specific stuff.
Test: treehugger
Change-Id: Id42e5b8a51ed73155be020d74edd7011a2103574
In particular, it contains all the riscv64 definitions we need, and lets
us clear up a lot of our existing ELF headers.
The other two BSDs seem to have errors and/or gaps in their riscv64
constants.
Test: treehugger
Change-Id: I92e48ef56c52c271ff6ed341b82169aa91f11d98
Musl doesn't provide the resolv b64_* functions, but adb uses them.
Export them from bionic.
Bug: 190084016
Test: m USE_HOST_MUSL=true host-native
Change-Id: I37837e6179a15754d4cbd89e67649df9dea9d9f1
This is purely a port: it does not add or change any functionality
(other than renaming the library).
Bug: 182498247
Test: Use library.
Change-Id: I4cb8f1c22ca4ca5a398116952fb9957d283d235b
Auto-generate NOTICE files for all the directories, and for each one
individually rather than mixing libc and libm together.
Test: N/A
Change-Id: I7e251194a8805c4ca78fcc5675c3321bcd5abf0a
Use a note in executables to specify
(none|sync|async) heap tagging level. To be extended with (heap x stack x
globals) in the future. A missing note disables all tagging.
Bug: b/135772972
Test: bionic-unit-tests (in a future change)
Change-Id: Iab145a922c7abe24cdce17323f9e0c1063cc1321
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
This benchmarks mapping property prefixes to property contexts with
two algorithms: the 'Legacy' method used before Android P and the
'Trie' used afterwards (the code in this directory).
It uses input mappings from both Oreo and the latest in AOSP ('S').
Note that there is nearly a 10x increase in the number of mappings in
S as there was in Oreo, which was predicted when the trie was
designed.
Results on cuttlefish:
-----------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------
LegacyLookupOreo 683576 ns 673538 ns 1060
LegacyLookupS 5683109 ns 5596982 ns 124
TrieLookupOreo 299851 ns 295696 ns 2378
TrieLookupS 584831 ns 576801 ns 1204
The results show that the legacy look up uses 8.3x more CPU time to
handle the number of mappings added through S, whereas the Trie lookup
uses less than 2x more CPU time, showing that the trie scales better
with added mappings.
Test: run this benchmark
Change-Id: I35c3aa4429f049e327a891f9cbe1901d8855d7ba
Now we're being marked down for our poor coverage, we may as well remove
more broken cruft. Despite the amount of effort that seems to have gone
into pututline(), it wasn't working with the other utmp.h functions (in
particular, utmpname()), and wasn't declared in the header file!
Test: treehugger
Change-Id: I1a583984189c751168c11c01431433f96f8c548b
Similar to the musl strstr. This patch also increases test coverage for
memmem, again similar to the strstr tests.
Test: treehugger
Change-Id: I7f4a2ab93a610cb692994d06d2512976e657ae9f
Simplify:
- Use a single memory-mapped region to hold the table of destructors.
Double its capacity each time it is expanded.
- Add a recompaction pass at the end of __cxa_finalize that shifts
entries forward and uses madvise to clean pages.
Bug: http://b/148055738
Test: bionic-unit-tests
Change-Id: Ieb9da2b88640a8a5277d217b43826b5b7e246781
Use O_PATH like musl to let the kernel do the hard work, rather than the
traditional BSD manual scheme.
Also add the most obvious missing tests from reading the man page, plus
a non-obvious test for deleted files.
Bug: http://b/131435126
Test: treehugger
Change-Id: Ie8a8986fea55f045952a81afee377ce8288a49d5
The libstdc++ directory has no copyright headers, so it was a no-op
anyway.
The interesting part will be switching libc and libm over to genrules...
Test: N/A
Change-Id: Iec92562af40c451fdcb4a7468984878ec5dba2ce
For ELF TLS "local-exec" accesses, the static linker assumes that an
executable's TLS segment is located at a statically-known offset from the
thread pointer (i.e. "variant 1" for ARM and "variant 2" for x86).
Because these layouts are incompatible, Bionic generally needs to allocate
its TLS slots differently between different architectures.
To allow per-architecture TLS slots:
- Replace the TLS_SLOT_xxx enumerators with macros. New ARM slots are
generally negative, while new x86 slots are generally positive.
- Define a bionic_tcb struct that provides two things:
- a void* raw_slots_storage[BIONIC_TLS_SLOTS] field
- an inline accessor function: void*& tls_slot(size_t tpindex);
For ELF TLS, it's necessary to allocate a temporary TCB (i.e. TLS slots),
because the runtime linker doesn't know how large the static TLS area is
until after it has loaded all of the initial solibs.
To accommodate Golang, it's necessary to allocate the pthread keys at a
fixed, small, positive offset from the thread pointer.
This CL moves the pthread keys into bionic_tls, then allocates a single
mapping per thread that looks like so:
- stack guard
- stack [omitted for main thread and with pthread_attr_setstack]
- static TLS:
- bionic_tcb [exec TLS will either precede or succeed the TCB]
- bionic_tls [prefixed by the pthread keys]
- [solib TLS segments will be placed here]
- guard page
As before, if the new mapping includes a stack, the pthread_internal_t
is allocated on it.
At startup, Bionic allocates a temporary bionic_tcb object on the stack,
then allocates a temporary bionic_tls object using mmap. This mmap is
delayed because the linker can't currently call async_safe_fatal() before
relocating itself.
Later, Bionic allocates a stack-less thread mapping for the main thread,
and copies slots from the temporary TCB to the new TCB.
(See *::copy_from_bootstrap methods.)
Bug: http://b/78026329
Test: bionic unit tests
Test: verify that a Golang app still works
Test: verify that a Golang app crashes if bionic_{tls,tcb} are swapped
Merged-In: I6543063752f4ec8ef6dc9c7f2a06ce2a18fc5af3
Change-Id: I6543063752f4ec8ef6dc9c7f2a06ce2a18fc5af3
(cherry picked from commit 1e660b70da)
The only 2019 android copyright is coming from a test file, which is
not included in our normal notice.
Test: Can upload.
Change-Id: Ie22332f927b99c28eb71c1daf5615adfef8c5d11
By default, Clang uses this arm32 function to read the thread pointer,
either for ELF TLS or via __builtin_thread_pointer(). It's probably better
to inline the cp15 access using -mtp=cp15, but that's not the default yet.
See https://reviews.llvm.org/D34878?id=114573.
Bug: http://b/78026329
Test: bionic unit tests
Change-Id: I93b8926075f0b2cea8df9ef518d54f2820a8ff5b
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
This reverts commit 253a830631 and moves
us forward to a revision that contains fixes for the problem with the
previous attempt.
This also makes sincos(3)/sincosf(3)/sincosl(3) available to `_BSD_SOURCE`
as well as `_GNU_SOURCE`.
The new FreeBSD libm code requires the FreeBSD `__CONCAT` macro, and all
our existing callers are FreeBSD too, so update that.
There's also an assumption that <complex.h> drags in <math.h> which isn't
true for us, so work around that with `-include` in the makefile. This
then causes clang to recognize a bug -- returning from a void function --
in our fake (LP32) sincosl(3), so fix that too.
Bug: http://b/111710419
Change-Id: I84703ad844f8afde6ec6b11604ab3c096ccb62c3
Test: ran tests
This includes an ld128 powl, plus the clog* and cpow* families.
Also teach the NOTICE generator to strip SPDX-License-Identifier lines.
Bug: N/A
Test: ran tests
Change-Id: Ic8289d1253666a19468a4088884cf7540f1ec66d
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
