There is no specific reason for this other than blocking
the most ancient versions. These are still old:
Autoconf 2.69 (2012)
Automake 1.12 (2012)
gettext 0.19.6 (2015)
Libtool 2.4 (2010)
This bumps the version requirement from 0.19 (from 2014) to
0.19.6 (2015).
Using only the old AM_GNU_GETTEXT_VERSION results in old
gettext infrastructure being placed in the package. By using
both macros we get the latest gettext files while the other
programs in the Autotools family can still see the old macro.
I don't know if the problem is in gnulib's gl_POSIX_SHELL macro
or if xzgrep does something that isn't in POSIX. The workaround
adds a special case for Solaris: if /usr/xpg4/bin/sh exists and
gl_cv_posix_shell wasn't overriden on the configure command line,
use that shell for xzgrep and other scripts. That shell is known
to work and exists on most Solaris systems.
This adds a configure option --enable-path-for-scripts=PREFIX
which defaults to empty except on Solaris it is /usr/xpg4/bin
to make POSIX grep and others available. The Solaris case had
been documented in INSTALL with a manual fix but it's better
to do this automatically since it is needed on most Solaris
systems anyway.
Thanks to Daniel Richard G.
This is the sane thing to do. The conflict with OpenSSL
on some OSes and especially that the OS-provided versions
can be significantly slower makes it clear that it was
a mistake to have the external SHA-256 support enabled by
default.
Those who want it can now pass --enable-external-sha256 to
configure. INSTALL was updated with notes about OSes where
this can be a bad idea.
The SHA-256 detection code in configure.ac had some bugs that
could lead to a build failure in some situations. These were
fixed, although it doesn't matter that much now that the
external SHA-256 is disabled by default.
MINIX >= 3.2.0 uses NetBSD's libc and thus has SHA256_Init
in libc instead of libutil. Support for the libutil version
was removed.
On FreeBSD 10 and older, SHA256_Init from libmd conflicts
with libcrypto from OpenSSL. The OpenSSL version has
different sizeof(SHA256_CTX) and it can cause weird
problems if wrong SHA256_Init gets used.
Looking at the source, MINIX 3 seems to have a similar issue but
I'm not sure. To be safe, I disabled SHA256_Init on MINIX 3 too.
NetBSD has SHA256_Init in libc and they had a similar problem,
but they already fixed it in 2009.
Thanks to Jim Wilcoxson for the bug report that helped
in finding the problem.
The patch is quite long but it's mostly about adding new #ifdefs
to omit code when encoders or decoders have been disabled.
This adds two new #defines to config.h: HAVE_ENCODERS and
HAVE_DECODERS.
Now it gives an error if LZMA1 encoder/decoder is missing
when LZMA2 encoder/decoder was requested. Even better would
be LZMA2 implicitly enabling LZMA1 but it would need more code.
This reverts commit 7a11c4a8e5.
It is a problem when libc has pipe2() but the kernel is too
old to have pipe2() and thus pipe2() fails. In xz it's pointless
to have a fallback for non-functioning pipe2(); it's better to
avoid pipe2() completely.
Thanks to Michael Fox for the bug report.
The sandboxing is used conditionally as described in main.c.
This isn't optimal but it was much easier to implement than
a full sandboxing solution and it still covers the most common
use cases where xz is writing to standard output. This should
have practically no effect on performance even with small files
as fork() isn't needed.
C and locale libraries can open files as needed. This has been
fine in the past, but it's a problem with things like Capsicum.
io_sandbox_enter() tries to ensure that various locale-related
files have been loaded before cap_enter() is called, but it's
possible that there are other similar problems which haven't
been seen yet.
Currently Capsicum is available on FreeBSD 10 and later
and there is a port to Linux too.
Thanks to Loganaden Velvindron for help.
Clang and nowadays also GCC accept any -Wfoobar option
but then may give a warning that an unknown warning option
was specified. To avoid adding unsupported warning options,
the options are now tested with -Werror.
Thanks to Charles Diza.
This commit just adds the function. Its uses will be in
separate commits.
This hasn't been tested much yet and it's perhaps a bit early
to commit it but if there are bugs they should get found quite
quickly.
Thanks to Jun I Jin from Intel for help and for pointing out
that string comparison needs to be optimized in liblzma.
Now liblzma only uses "mythread" functions and types
which are defined in mythread.h matching the desired
threading method.
Before Windows Vista, there is no direct equivalent to
pthread condition variables. Since this package doesn't
use pthread_cond_broadcast(), pre-Vista threading can
still be kept quite simple. The pre-Vista code doesn't
use anything that wasn't already available in Windows 95,
so the binaries should run even on Windows 95 if someone
happens to care.
Previously it was done in configure, but doing that goes
against the Autoconf manual. Autoconf requires that it is
possible to override e.g. prefix after running configure
and that doesn't work correctly if liblzma.pc is created
by configure.
A potential downside of this change is that now e.g.
libdir in liblzma.pc is a standalone string instead of
being defined via ${prefix}, so if one overrides prefix
when running pkg-config the libdir won't get the new value.
I don't know if this matters in practice.
Thanks to Vincent Torri.
It should actually still work with Automake 1.10 if
the serial-tests option is removed. Automake 1.13 started
using parallel tests by default and the option to get
the old behavior isn't supported before 1.12.
At least for now, parallel tests don't improve anything
in XZ Utils but they hide the progress output from
test_compress.sh.
Variable-length arrays are mandatory in C99 but optional in C11.
The code doesn't currently use any VLAs and it shouldn't in the
future either to stay compatible with C11 without requiring any
optional C11 features.
The scripts are now made executable in the build tree.
This way the scripts can be run like programs in
test_scripts.sh. Previously test_scripts.sh always
used sh but it's not correct if @POSIX_SHELL@ is set
to something else by configure.
Thanks to Jonathan Nieder for the patch.
Symbol versioning is enabled by default on GNU/Linux,
other GNU-based systems, and FreeBSD.
I'm not sure how stable this is, so it may need
backward-incompatible changes before the next release.
The idea is that alpha and beta symbols are considered
unstable and require recompiling the applications that
use those symbols. Once a symbol is stable, it may get
extended with new features in ways that don't break
compatibility with older ABI & API.
The mydist target runs validate_map.sh which should
catch some probable problems in liblzma.map. Otherwise
I would forget to update the map file for new releases.
If the operating system libc or other base libraries
provide SHA-256, use that instead of our own copy.
Note that this doesn't use OpenSSL or libgcrypt or
such libraries to avoid creating dependencies to
other packages.
This supports at least FreeBSD, NetBSD, OpenBSD, Solaris,
MINIX, and Darwin. They all provide similar but not
identical SHA-256 APIs; everyone is a little different.
Thanks to Wim Lewis for the original patch, improvements,
and testing.
Use gettimeofday() if clock_gettime() isn't available
(e.g. Darwin).
The test for availability of pthread_condattr_setclock()
and CLOCK_MONOTONIC was incorrect. Instead of fixing the
#ifdefs, use an Autoconf test. That way if there exists a
system that supports them but doesn't specify the matching
POSIX #defines, the features will still get detected.
Don't try to use pthread_sigmask() on OpenVMS. It doesn't
have that function.
Guard mythread.h against being #included multiple times.
This is the simplest method to do threading, which splits
the uncompressed data into blocks and compresses them
independently from each other. There's room for improvement
especially to reduce the memory usage, but nevertheless,
this is a good start.
This adds:
- mythread_sync() macro to create synchronized blocks
- mythread_cond structure and related functions
and macros for condition variables with timed
waiting using a relative timeout
- mythread_create() to create a thread with all
signals blocked
Some of these wouldn't need to be inline functions,
but I'll keep them this way for now for simplicity.
For timed waiting on a condition variable, librt is
now required on some systems to use clock_gettime().
configure.ac was updated to handle this.
