The bug is only a problem in applications that do not properly terminate
the filters[] array with LZMA_VLI_UNKNOWN or have more than
LZMA_FILTERS_MAX filters. This bug does not affect xz.
Added a few sentences to the description for lzma_block_encoder() and
lzma_block_decoder() to highlight that the Block Header must be coded
before calling these functions.
Standardizing each function to always specify params and return values.
Output pointer parameters are also marked with doxygen style [out] to
make it clear. Any note sections were also moved above the parameter and
return sections for consistency.
The flag description for LZMA_STR_NO_VALIDATION was previously confusing
about the treatment for filters than cannot be used with .xz format
(lzma1) without using LZMA_STR_ALL_FILTERS. Now, it is clear that
LZMA_STR_NO_VALIDATION is not a super set of LZMA_STR_ALL_FILTERS.
The previous documentation for lzma_str_to_filters() was technically
correct, but misleading. lzma_str_to_filters() returns NULL on success,
which is in practice always defined to 0. This is the same value as
LZMA_OK, but lzma_str_to_filters() does not return lzma_ret so we should
be more clear.
tuklib_physmem depends on GetProcAddress() for both MSVC and MinGW-w64
to retrieve a function address. The proper way to do this is to cast the
return value to the type of function pointer retrieved. Unfortunately,
this causes a cast-function-type warning, so the best solution is to
simply ignore the warning.
Calling coder_set_compression_settings() in list mode with verbose mode
on caused the filter chain and memory requirements to print. This was
unnecessary since the command results in an error and not consistent
with other formats like lzma and alone.
It doesn't warn on a 64-bit system because truncating
a ptrdiff_t (signed long) to uint32_t is diagnosed under
-Wconversion by GCC and -Wshorten-64-to-32 by Clang.
This is similar to 2ce4f36f17.
The actual initialization of the variables is done inside
mythread_sync() macro. Clang doesn't seem to see that
the initialization code inside the macro is always executed.
On some platforms src/xz/suffix.c may need <strings.h> for
strcasecmp() but suffix.c includes the header when it needs it.
Unless there is an old system that otherwise supports enough C99
to build XZ Utils but doesn't have C89/C90-compatible <string.h>,
there should be no need to include <strings.h> in sysdefs.h.
SUSv2 and POSIX.1‐2017 declare only a few functions in <strings.h>.
Of these, strcasecmp() is used on some platforms in suffix.c.
Nothing else in the project needs <strings.h> (at least if
building on a modern system).
sysdefs.h currently includes <strings.h> if HAVE_STRINGS_H is
defined and suffix.c relied on this.
Note that dos/config.h doesn't #define HAVE_STRINGS_H even though
DJGPP does have strings.h. It isn't needed with DJGPP as strcasecmp()
is also in <string.h> in DJGPP.
clang and gcc differ in how they handle -Wformat-nonliteral. gcc will
allow a non-literal format string as long as the function takes its
format arguments as a va_list.
This affects only 32-bit x86 builds. x86-64 is OK as is.
I still cannot easily test this myself. The reporter has tested
this and it passes the tests included in the CMake build and
performance is good: raw CRC64 is 2-3 times faster than the
C version of the slice-by-four method. (Note that liblzma doesn't
include a MSVC-compatible version of the 32-bit x86 assembly code
for the slice-by-four method.)
Thanks to Iouri Kharon for figuring out a fix, testing, and
benchmarking.
This reverts commit 36edc65ab4.
It was reported that it wasn't a good enough fix and MSVC
still produced (different kind of) bad code when building
for 32-bit x86 if optimizations are enabled.
Thanks to Iouri Kharon.
It quite probably was never needed, that is, any system where memory.h
was required likely couldn't compile XZ Utils for other reasons anyway.
XZ Utils 5.2.6 and later source packages were generated using
Autoconf 2.71 which no longer defines HAVE_MEMORY_H. So the code
being removed is no longer used anyway.
I haven't tested with MSVC myself and there doesn't seem to be
information about the problem online, so I'm relying on the bug report.
Thanks to Iouri Kharon for the bug report and the patch.
common/index.h is needed by liblzma internally and tests. common.h will
include and define many things that are not needed by the tests.
Also, this prevents include order problems because both common.h and
lzma.h define LZMA_API. On most platforms it results only in a warning
but on Windows it would break the build as the definition in common.h
must be used only for building liblzma itself.
HAVE_DECL_PROGRAM_INVOCATION_NAME is renamed to
HAVE_PROGRAM_INVOCATION_NAME. Previously,
HAVE_DECL_PROGRAM_INVOCATION_NAME was always set when
building with autotools. CMake would only set this when it was 1, and the
dos/config.h did not define it. The new macro definition is consistent
across build systems.
Previously, <sys/time.h> was always included, even if mythread only used
clock_gettime. <time.h> is still needed even if clock_gettime is not used
though because struct timespec is needed for mythread_condtime.
Previously, if threading was enabled HAVE_DECL_CLOCK_MONOTONIC would always
be set to 0 or 1. However, this macro was needed in xz so if xz was not
built with threading and HAVE_DECL_CLOCK_MONOTONIC was not defined but
HAVE_CLOCK_GETTIME was, it caused a warning during build. Now,
HAVE_DECL_CLOCK_MONOTONIC has been renamed to HAVE_CLOCK_MONOTONIC and
will only be set if it is 1.
Using return_if_error on lzma_lzma_lclppb_encode was improper because
return_if_error is expecting an lzma_ret value, but
lzma_lzma_lclppb_encode returns a boolean. This could result in
lzma_microlzma_encoder, which would be misleading for applications.
The code that parses --memlimit options and --block-list modified
the argv[] when parsing the option string from optarg. This was
visible in "ps auxf" and such and could be confusing. I didn't
understand it back in the day when I wrote that code. Now a copy
is allocated when modifiable strings are needed.
The API docs gave an impression that such checks are done
but they actually weren't done. In practice it made little
difference since the calling code has a bug if these are NULL.
Thanks to Jia Tan for the original patch that checked for
block->filters == NULL.
If someone sets up Clang to define __GNUC__ to 10 or greater
then symvers broke. __has_attribute is supported by such GCC
and Clang versions that don't support __symver__ so this should
be much better and simpler way to detect if __symver__ is
actually supported.
Thanks to Tomasz Gajc for the bug report.
It has some complicated downsides and its usefulness is more limited
than I originally thought. So this change is bad for certain very
specific situations but a generic solution that works for other
filters (and is otherwise better too) is planned anyway. And this
way 7-Zip can use the same compatible filter for the .7z format.
This is still marked as experimental with a new temporary Filter ID.
lzma_str_to_filters() uses static error messages which makes
them not very precise. It tells the position in the string
where an error occurred though which helps quite a bit if
applications take advantage of it. Dynamic error messages can
be added later with a new flag if it seems important enough.
Some file formats need support for LZMA1 streams that don't use
the end of payload marker (EOPM) alias end of stream (EOS) marker.
So far liblzma API has supported decompressing such streams via
lzma_alone_decoder() when .lzma header specifies a known
uncompressed size. Encoding support hasn't been available in the API.
Instead of adding a new LZMA1-only API for this purpose, this commit
adds a new filter ID for use with raw encoder and decoder. The main
benefit of this approach is that then also filter chains are possible,
for example, if someone wants to implement support for .7z files that
use the x86 BCJ filter with LZMA1 (not BCJ2 as that isn't supported
in liblzma).
That is, if the specified nice_len is smaller than the minimum
of the match finder, silently use the match finder's minimum value
instead of reporting an error. The old behavior is annoying to users
and it complicates xz options handling too.
It not only makes no sense to put symbol versions into a static library
but it can also cause breakage.
By default Libtool #defines PIC if building a shared library and
doesn't define it for static libraries. This is documented in the
Libtool manual. It can be overriden using --with-pic or --without-pic.
configure.ac detects if --with-pic or --without-pic is used and then
gives an error if neither --disable-shared nor --disable-static was
used at the same time. Thus, in normal situations it works to build
both shared and static library at the same time on GNU/Linux,
only --with-pic or --without-pic requires that only one type of
library is built.
Thanks to John Paul Adrian Glaubitz from Debian for reporting
the problem that occurred on ia64:
https://www.mail-archive.com/xz-devel@tukaani.org/msg00610.html
lzma_filters_free() sets the options to NULL and ids to
LZMA_VLI_UNKNOWN so there is no need to do it by caller;
the filter arrays will always be left in a safe state.
Also use memcpy() instead of a loop to copy a filter chain
when it is known to be safe to copy LZMA_FILTERS_MAX + 1
(even if the elements past the terminator might be uninitialized).
This time it can happen when lzma_stream_encoder_mt() is used
to reinitialize an existing multi-threaded Stream encoder
and one of 1-4 tiny allocations in lzma_filters_copy() fail.
It's very similar to the previous bug
10430fbf38, happening with
an array of lzma_filter structures whose old options are freed
but the replacement never arrives due to a memory allocation
failure in lzma_filters_copy().
The documentation mentions that lzma_block_encoder() supports
LZMA_SYNC_FLUSH but it was never added to supported_actions[]
in the internal structure. Because of this, LZMA_SYNC_FLUSH could
not be used with the Block encoder unless it was the next coder
after something like stream_encoder() or stream_encoder_mt().
The bug was in the single-threaded .xz Stream encoder
in the code that is used for both re-initialization and for
lzma_filters_update(). To trigger it, an application had
to either re-initialize an existing encoder instance with
lzma_stream_encoder() or use lzma_filters_update(), and
then one of the 1-4 tiny allocations in lzma_filters_copy()
(called from stream_encoder_update()) must fail. An error
was correctly reported but the encoder state was corrupted.
This is related to the recent fix in
f8ee61e74e which is good but
it wasn't enough to fix the main problem in stream_encoder.c.
The encoder doesn't support dictionary sizes larger than 1536 MiB.
This is validated, for example, when calculating the memory usage
via lzma_raw_encoder_memusage(). It is also enforced by the LZ
part of the encoder initialization. However, LZMA encoder with
LZMA_MODE_NORMAL did an unsafe calculation with dict_size before
such validation and that results in an infinite loop if dict_size
was 2 << 30 or greater.
This reverts commit 177bdc922c
and also does equivalent change to arm64.c.
Now that ARM64 filter will use lzma_options_bcj, this change
is not needed anymore.
It also works on E2K as it supports these intrinsics.
On x86-64 runtime detection is used so the code keeps working on
older processors too. A CLMUL-only build can be done by using
-msse4.1 -mpclmul in CFLAGS and this will reduce the library
size since the generic implementation and its 8 KiB lookup table
will be omitted.
On 32-bit x86 this isn't used by default for now because by default
on 32-bit x86 the separate assembly file crc64_x86.S is used.
If --disable-assembler is used then this new CLMUL code is used
the same way as on 64-bit x86. However, a CLMUL-only build
(-msse4.1 -mpclmul) won't omit the 8 KiB lookup table on
32-bit x86 due to a currently-missing check for disabled
assembler usage.
The configure.ac check should be such that the code won't be
built if something in the toolchain doesn't support it but
--disable-clmul-crc option can be used to unconditionally
disable this feature.
CLMUL speeds up decompression of files that have compressed very
well (assuming CRC64 is used as a check type). It is know that
the CLMUL code is significantly slower than the generic code for
tiny inputs (especially 1-8 bytes but up to 16 bytes). If that
is a real-world problem then there is already a commented-out
variant that uses the generic version for small inputs.
Thanks to Ilya Kurdyukov for the original patch which was
derived from a white paper from Intel [1] (published in 2009)
and public domain code from [2] (released in 2016).
[1] https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
[2] https://github.com/rawrunprotected/crc
This uses it for CRC table initializations when using --disable-small.
It avoids mythread_once() overhead. It also means that then
--disable-small --disable-threads is thread-safe if this attribute
is supported.
__SSE2__ is the correct macro for SSE2 support with GCC, Clang,
and ICC. __SSE2_MATH__ means doing floating point math with SSE2
instead of 387. Often the latter macro is defined if the first
one is but it was still a bug.
In practice this means making the scripts work when
the input files have an unsupported check type which
isn't a problem in practice unless support for
some check types has been disabled at build time.
Modern 32-bit ARM in big endian mode use little endian for
instruction encoding still, so the filters work on such
executables too. It's likely less confusing for users this way.
The --arm64 option hasn't been implemented yet (there is
--experimental-arm64 but it's different). The --arm64 option
is added now anyway because this is the likely result and the
strings need to be ready for translators.
Thanks to Jia Tan.
Jia Tan
Lasse Collin