If the cache variable TUKLIB_FAST_UNALIGNED_ACCESS is already set,
the autodetection result isn't needed because the option() command
does nothing when the cache variable is already set.
This is largely white space change to indent the if...endif block.
CMake >= 4.1 sets CMAKE_<LANG>_COMPILER_ARCHITECTURE_ID on many
platforms. The list of possible values are documented. Use this
variable when available. On older CMake versions CMAKE_SYSTEM_PROCESSOR
is still used, thus the regexes have to include values like ^amd64 still.
With old CMake versions, checking CMAKE_C_COMPILER_ARCHITECTURE_ID
is somewhat useful with MSVC because CMAKE_SYSTEM_PROCESSOR might
not match the target architecture.
On ARM64, support for fast unaligned memory access was autodetected by
checking if __ARM_FEATURE_UNALIGNED is defined. However, at least GCC
versions up to 15.2.0 define the macro even when -mstrict-align has
been specified. Thus, autodetection with GCC doesn't work correctly,
and binaries built using -mstrict-align can be much slower than they
need to be, unless the user also passes --disable-unaligned-access
to configure or -DTUKLIB_FAST_UNALIGNED_ACCESS=OFF to cmake.
See the GCC bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111555
Workaround the issue by using heuristics with GCC on ARM64.
With Clang, the detection using __ARM_FEATURE_UNALIGNED works.
It also works with GCC on 32-bit ARM.
Fixes: e5f13a66567b ("tuklib_integer: Autodetect support for unaligned access on ARM.")
There are no strings to translate in that file now, but it's good to
list it anyway in case translatable strings are added in the future.
Fixes: 374868d81d47 ("xz: Move sandboxing code to sandbox.c and improve Landlock sandbox.")
This was already the case in practice because I had forgotten to list
src/xz/sandbox.c in po/POTFILES.in. However, it seems better to never
translate this particular error message. It should almost never occur
and if it does, an untranslated message is should make it easier to
find bug reports about it.
This still relies on CMAKE_SYSTEM_PROCESSOR. CMake 4.1 added more
CMAKE_<LANG>_COMPILER_ARCHITECTURE_ID values to detect the arch in
a more defined manner, but 4.1 is too new to require for now.
Thanks-to: Li Chenggang <lichenggang@deepin.org>
Closes: https://github.com/tukaani-project/xz/pull/186
According to [1] sections 7.4, 8.1, and 8.2, desktop and server
processors support fast unaligned access, but embedded systems likely
don't.
It's important that TUKLIB_FAST_UNALIGNED_ACCESS isn't defined when
-mstrict-align is in use because it will result in slower binaries
even if running on a processor that supports fast unaligned access.
It's because compilers will translate multibyte memcpy() to multiple
byte-by-byte instructions instead of wider loads and stores. The
compression times from [2] show this well:
Unaligned access CFLAGS Compression time
enabled -O2 -mno-strict-align 66.1 s
disabled -O2 -mno-strict-align 79.5 s
disabled -O2 -mstrict-align 79.9 s
enabled -O2 -mstrict-align 129.1 s
There currently (GCC 15.2) is no preprocessor macro on LoongArch
to detect if -mstrict-align or -mno-strict-align is in effect (the
default is -mno-strict-align). Use heuristics to detect which of the
flags is in effect.
[1] https://github.com/loongson/la-softdev-convention/blob/v0.2/la-softdev-convention.adoc
[2] https://github.com/tukaani-project/xz/pull/186#issuecomment-3494570304
Thanks-to: Li Chenggang <lichenggang@deepin.org>
Thanks-to: Xi Ruoyao
See: https://github.com/tukaani-project/xz/pull/186
lzma_lzma_decoder_memusage() returns UINT64_MAX if lc/lp/pb aren't
valid. alone_decoder.c and lzip_decoder.c didn't check the return
value because in both it is known that lc/lp/pb are valid. Make them
call the _nocheck() variant instead which skips the validation (it
already existed for LZMA2's internal use).
Fixes: Coverity CID 464658
Fixes: Coverity CID 897069
The partial_update_mode enumeration had three states, _DISABLED,
_START, and _ENABLED. Main thread changed it from _DISABLED to _START
while holding a mutex. Once set to _START, worker thread changed it
to _ENABLED without a mutex. Later main thread read it without a mutex,
so it could see either _START or _ENABLED. However, it made no
difference because the main thread checked for != _DISABLED, so
it didn't matter if it saw _START or _ENABLED.
Nevertheless, such things must not be done. It's clear it was a mistake
because there were two comments that directly contradicted each
other about how the variable was accessed.
Split the enumeration into two booleans:
- partial_update_enabled: A worker thread locks the mutex to read
this variable and the main thread locks the mutex to change the
value. Because only the main thread modifies the variable, the
main thread can read the value without locking the mutex.
This variable replaces the _DISABLED -> _START transition.
- partial_update_started is for worker thread's internal use and thus
needs no mutex. This replaces the _START -> _ENABLED transition.
Fixes: Coverity CID 456025
Fixes: bd93b776c1bd ("liblzma: Fix a deadlock in threaded decoder.")
In short, sort the names with this command (-k1,1 isn't needed because
the lines with names start with " -"):
LC_ALL=en_US.UTF-8 sort -k2,2 -k3,3 -k4,4 -k5,5
When THANKS was created, I wrote the names as "First Last" and attempted
to keep them sorted by last name / surname / family name. This works
with many names in THANKS, but it becomes complicated with names that
don't fit that pattern. For example, names that are written as
"Last First" can be manually sorted by family name, but only if one
knows which part of the name is the family name.[*] And of course,
the concept of first/last name doesn't apply to all names.
[*] xz had a co-maintainer who could help me with such names,
but fortunately he isn't working on the project anymore.
Adding the names in chronological order could have worked too, although
if something is contributed by multiple people, one would still have to
decide how to sort the names within the batch. Another downside would
be that if THANKS is updated in more than one work-in-progress branch,
merge conflicts would occur more often.
Don't attempt to sort by last name. Let's be happy that people tend to
provide names that can be expressed in a reasonable number of printable
Unicode characters. In practice, people have been even nicer: if the
native language doesn't use a Latin script alphabet, people often provide
a transliterated name (only or in addition to the original spelling),
which is very much appreciated by those who don't know the native script.
Treat the names as opaque strings or space-separated strings for sorting
purposes. This means that most names will now be sorted by first name.
There still are many choices how to sort:
(1) LC_ALL=en_US.UTF-8 sort
The project is in English, so this may sound like a logical choice.
However, spaces have a lower weight than letters, which results in
this order:
- A Ba
- Ab C
- A Bc
- A Bd
(2) LC_ALL=en_US.UTF-8 sort -k2,2
This first sorts by the first word and then by the rest of the
string. It's -k2,2 instead of -k1,1 to skip the leading dash.
- A Ba
- A Bc
- A Bd
- Ab C
I like this more than (1). One could add -k3,3 -k4,4 -k5,5 ... too.
With current THANKS it makes no difference but it might some day.
NOTE: The ordering in en_US.UTF-8 can differ between libc versions
and operating systems. Luckily it's not a big deal in THANKS.
(3) LC_ALL=en_US.UTF-8 sort -f -k2,2
Passing -f (--ignore-case) to sort affects sorting of single-byte
characters but not multibyte characters (GNU coreutils 9.9):
No -f With -f LC_ALL=C
Aa A.A A.A
A.A Aa Aa
Ää Ää Ä.Ä
Ä.Ä Ä.Ä Ää
In GNU coreutils, the THANKS file is sorted using "sort -f -k1,1".
There is also a basic check that the en_US.UTF-8 locale is
behaving as expected.
(4) LC_ALL=C sort
This sorts by byte order which in UTF-8 is the same as Unicode
code point order. With the strings in (1) and (2), this produces
the same result as in (2). The difference in (3) can be seen above.
The results differ from en_US.UTF-8 when a name component starts
with a lower case ASCII letter (like "von" or "de"). Worse, any
non-ASCII characters sort after ASCII chars. These properties might
look weird in English language text, although it's good to remember
that en_US.UTF-8 sorting can appear weird too if one's native
language isn't English.
The choice between (2) and (4) was difficult but I went with (2).
;-)
To make a non-threaded liblzma-only build work with WASI SDK, <signal.h>
and mythread_sigmask() were omitted from mythread.h in the commit
81db3b889830. This broke non-threaded full build with Emscripten because
src/xz/signals.c needs mythread_sigmask() (liblzma-only build was fine).
If __wasm__ is defined, omit <signal.h> and mythread_sigmask() in
non-threaded builds only when __EMSCRIPTEN__ isn't defined.
Reported-by: Marcus Tillmanns
Thanks-to: ChanTsune
Fixes: https://github.com/tukaani-project/xz/issues/161
Fixes: 81db3b889830 ("mythread.h: Disable signal functions in builds targeting Wasm + WASI.")
getauxval() can be available even if HWCAP_CRC32 isn't #defined, so
both have to be checked. HWCAP_CRC32 was added in glibc 2.24 (2016).
Fixes: https://github.com/tukaani-project/xz/issues/190
