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.
Using CMake to build liblzma should work on a few other OSes
but building the command line tools is still subtly broken.
It is known that shared library versioning may differ between
CMake and Libtool builds on some OSes, most notably Darwin.
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.
