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Author SHA1 Message Date
Lasse Collin
076e911ba2 Build: Use only the generic symbol versioning on MicroBlaze.
On MicroBlaze, GCC 12 is broken in sense that
__has_attribute(__symver__) returns true but it still doesn't
support the __symver__ attribute even though the platform is ELF
and symbol versioning is supported if using the traditional
__asm__(".symver ...") method. Avoiding the traditional method is
good because it breaks LTO (-flto) builds with GCC.

See also: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101766

For now the only extra symbols in liblzma_linux.map are the
compatibility symbols with the patch that spread from RHEL/CentOS 7.
These require the use of __symver__ attribute or __asm__(".symver ...")
in the C code. Compatibility with the patch from CentOS 7 doesn't
seem valuable on MicroBlaze so use liblzma_generic.map on MicroBlaze
instead. It doesn't require anything special in the C code and thus
no LTO issues either.

An alternative would be to detect support for __symver__
attribute in configure.ac and CMakeLists.txt and fall back
to __asm__(".symver ...") but then LTO would be silently broken
on MicroBlaze. It sounds likely that MicroBlaze is a special
case so let's treat it as a such because that is simpler. If
a similar issue exists on some other platform too then hopefully
someone will report it and this can be reconsidered.

(This doesn't do the same fix in CMakeLists.txt. Perhaps it should
but perhaps CMake build of liblzma doesn't matter much on MicroBlaze.
The problem breaks the build so it's easy to notice and can be fixed
later.)

Thanks to Vincent Fazio for reporting the problem and proposing
a patch (in the end that solution wasn't used):
https://github.com/tukaani-project/xz/pull/32
2023-03-07 23:23:29 +08:00
Lasse Collin
718f7a60e7 Build: Omit -Wmissing-noreturn from the default warnings.
It's not that important. It can be annoying in builds that
disable many features since in those cases the tests programs
will correctly trigger this warning with Clang.
2023-02-03 21:10:47 +08:00
Lasse Collin
b16b9c0d22 Build: Make configure add more warning flags for GCC and Clang.
-Wstrict-aliasing was removed from the list since it is enabled
by -Wall already.

A normal build is clean with these on GNU/Linux x86-64 with
GCC 12.2.0 and Clang 14.0.6.
2023-02-03 21:10:19 +08:00
Lasse Collin
52bc1ee34d Build: Require that _mm_set_epi64x() is usable to enable CLMUL support.
VS2013 doesn't have _mm_set_epi64x() so this way CLMUL gets
disabled with VS2013.

Thanks to Iouri Kharon for the bug report.
2023-01-09 16:58:27 +02:00
Lasse Collin
bfba3394ae Build: Fix config.h comments. 2023-01-05 00:29:52 +08:00
Jia Tan
9e3cb514b5 Build: No longer require HAVE_DECL_CLOCK_MONOTONIC to always be set.
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.
2023-01-05 00:26:35 +08:00
Lasse Collin
764955e2d4 Change the bug report address.
It forwards to me and Jia Tan.

Also update the IRC reference in README as #tukaani was moved
to Libera Chat long ago.
2022-11-30 18:08:34 +02:00
Lasse Collin
06824396b2 Build: Don't put GNU/Linux-specific symbol versions into static liblzma.
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
2022-11-24 14:52:44 +02:00
Lasse Collin
f644473a21 liblzma: Add fast CRC64 for 32/64-bit x86 using SSSE3 + SSE4.1 + CLMUL.
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
2022-11-14 23:05:46 +02:00
Lasse Collin
ac10b1b362 Build: Omit x86_64 from --enable-assembler.
It didn't do anything. There are only 32-bit x86 assembly files
and it feels likely that new files won't be added as intrinsics
in C are more portable across toolchains and OSes.
2022-11-14 17:58:07 +02:00
Lasse Collin
eb0f1450ad liblzma: Use __attribute__((__constructor__)) if available.
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.
2022-11-14 16:00:52 +02:00
Lasse Collin
0538db038f liblzma: Add .lz (lzip) decompression support (format versions 0 and 1).
Support for format version 0 was removed from lzip 1.18 for some
reason. .lz format version 0 files are rare (and old) but some
source packages were released in this format, and some people might
have personal files in this format too. It's very little extra code
to support it along side format version 1 so this commits adds
support for both.

The Sync Flush marker extentension to the original .lz format
version 1 isn't supported. It would require changes to the
LZMA decoder itself. Such files are very rare anyway.

See the API doc for lzma_lzip_decoder() for more details about
the .lz format support.

Thanks to Michał Górny for the original patch.
2022-11-09 14:24:20 +02:00
Lasse Collin
cf118c0146 Build: Clarify comment in configure.ac about SSE2. 2022-10-31 16:26:05 +02:00
Lasse Collin
aad3c609ff Build: Remove obsolete commented-out lines from configure.ac. 2022-10-31 16:16:37 +02:00
Lasse Collin
a4b214b93a Build: Use AC_CONFIG_HEADERS instead of the ancient AC_CONFIG_HEADER.
We require Autoconf >= 2.69 and that has AC_CONFIG_HEADERS.

There is a warning about AC_PROG_CC_C99 being obsolete but
it cannot be removed because it is needed with Autoconf 2.69.
2022-10-25 23:45:03 +03:00
Lasse Collin
59c4d6e139 Build: Add configure option --disable-microlzma.
MicroLZMA was made for EROFS and used by erofs-utils.
It might be used by something else in the future but
those wanting a smaller build for specific situations
can now disable this rarely-needed feature.
2022-10-25 23:28:34 +03:00
Lasse Collin
563288ea70 xz: Add support for OpenBSD's pledge() sandbox. 2022-10-25 21:30:48 +03:00
Lasse Collin
ecb966de30 liblzma: Add experimental ARM64 BCJ filter with a temporary Filter ID.
That is, the Filter ID will be changed once the design is final.
The current version will be removed. So files created with the
tempoary Filter ID won't be supported in the future.
2022-09-19 20:23:46 +03:00
Lasse Collin
913ddc5572 liblzma: Vaccinate against an ill patch from RHEL/CentOS 7.
RHEL/CentOS 7 shipped with 5.1.2alpha, including the threaded
encoder that is behind #ifdef LZMA_UNSTABLE in the API headers.
In 5.1.2alpha these symbols are under XZ_5.1.2alpha in liblzma.map.
API/ABI compatibility tracking isn't done between development
releases so newer releases didn't have XZ_5.1.2alpha anymore.

Later RHEL/CentOS 7 updated xz to 5.2.2 but they wanted to keep
the exported symbols compatible with 5.1.2alpha. After checking
the ABI changes it turned out that >= 5.2.0 ABI is backward
compatible with the threaded encoder functions from 5.1.2alpha
(but not vice versa as fixes and extensions to these functions
were made between 5.1.2alpha and 5.2.0).

In RHEL/CentOS 7, XZ Utils 5.2.2 was patched with
xz-5.2.2-compat-libs.patch to modify liblzma.map:

  - XZ_5.1.2alpha was added with lzma_stream_encoder_mt and
    lzma_stream_encoder_mt_memusage. This matched XZ Utils 5.1.2alpha.

  - XZ_5.2 was replaced with XZ_5.2.2. It is clear that this was
    an error; the intention was to keep using XZ_5.2 (XZ_5.2.2
    has never been used in XZ Utils). So XZ_5.2.2 lists all
    symbols that were listed under XZ_5.2 before the patch.
    lzma_stream_encoder_mt and _mt_memusage are included too so
    they are listed both here and under XZ_5.1.2alpha.

The patch didn't add any __asm__(".symver ...") lines to the .c
files. Thus the resulting liblzma.so exports the threaded encoder
functions under XZ_5.1.2alpha only. Listing the two functions
also under XZ_5.2.2 in liblzma.map has no effect without
matching .symver lines.

The lack of XZ_5.2 in RHEL/CentOS 7 means that binaries linked
against unpatched XZ Utils 5.2.x won't run on RHEL/CentOS 7.
This is unfortunate but this alone isn't too bad as the problem
is contained within RHEL/CentOS 7 and doesn't affect users
of other distributions. It could also be fixed internally in
RHEL/CentOS 7.

The second problem is more serious: In XZ Utils 5.2.2 the API
headers don't have #ifdef LZMA_UNSTABLE for obvious reasons.
This is true in RHEL/CentOS 7 version too. Thus now programs
using new APIs can be compiled without an extra #define. However,
the programs end up depending on symbol version XZ_5.1.2alpha
(and possibly also XZ_5.2.2) instead of XZ_5.2 as they would
with an unpatched XZ Utils 5.2.2. This means that such binaries
won't run on other distributions shipping XZ Utils >= 5.2.0 as
they don't provide XZ_5.1.2alpha or XZ_5.2.2; they only provide
XZ_5.2 (and XZ_5.0). (This includes RHEL/CentOS 8 as the patch
luckily isn't included there anymore with XZ Utils 5.2.4.)

Binaries built by RHEL/CentOS 7 users get distributed and then
people wonder why they don't run on some other distribution.
Seems that people have found out about the patch and been copying
it to some build scripts, seemingly curing the symptoms but
actually spreading the illness further and outside RHEL/CentOS 7.

The ill patch seems to be from late 2016 (RHEL 7.3) and in 2017 it
had spread at least to EasyBuild. I heard about the events only
recently. :-(

This commit splits liblzma.map into two versions: one for
GNU/Linux and another for other OSes that can use symbol versioning
(FreeBSD, Solaris, maybe others). The Linux-specific file and the
matching additions to .c files add full compatibility with binaries
that have been built against a RHEL/CentOS-patched liblzma. Builds
for OSes other than GNU/Linux won't get the vaccine as they should
be immune to the problem (I really hope that no build script uses
the RHEL/CentOS 7 patch outside GNU/Linux).

The RHEL/CentOS compatibility symbols XZ_5.1.2alpha and XZ_5.2.2
are intentionally put *after* XZ_5.2 in liblzma_linux.map. This way
if one forgets to #define HAVE_SYMBOL_VERSIONS_LINUX when building,
the resulting liblzma.so.5 will have lzma_stream_encoder_mt@@XZ_5.2
since XZ_5.2 {...} is the first one that lists that function.
Without HAVE_SYMBOL_VERSIONS_LINUX @XZ_5.1.2alpha and @XZ_5.2.2
will be missing but that's still a minor problem compared to
only having lzma_stream_encoder_mt@@XZ_5.1.2alpha!

The "local: *;" line was moved to XZ_5.0 so that it doesn't need
to be moved around. It doesn't matter where it is put.

Having two similar liblzma_*.map files is a bit silly as it is,
at least for now, easily possible to generate the generic one
from the Linux-specific file. But that adds extra steps and
increases the risk of mistakes when supporting more than one
build system. So I rather maintain two files in parallel and let
validate_map.sh check that they are in sync when "make mydist"
is run.

This adds .symver lines for lzma_stream_encoder_mt@XZ_5.2.2 and
lzma_stream_encoder_mt_memusage@XZ_5.2.2 even though these
weren't exported by RHEL/CentOS 7 (only @@XZ_5.1.2alpha was
for these two). I added these anyway because someone might
misunderstand the RHEL/CentOS 7 patch and think that @XZ_5.2.2
(@@XZ_5.2.2) versions were exported too.

At glance one could suggest using __typeof__ to copy the function
prototypes when making aliases. However, this doesn't work trivially
because __typeof__ won't copy attributes (lzma_nothrow, lzma_pure)
and it won't change symbol visibility from hidden to default (done
by LZMA_API()). Attributes could be copied with __copy__ attribute
but that needs GCC 9 and a fallback method would be needed anyway.

This uses __symver__ attribute with GCC >= 10 and
__asm__(".symver ...") with everything else. The attribute method
is required for LTO (-flto) support with GCC. Using -flto with
GCC older than 10 is now broken on GNU/Linux and will not be fixed
(can silently result in a broken liblzma build that has dangerously
incorrect symbol versions). LTO builds with Clang seem to work
with the traditional __asm__(".symver ...") method.

Thanks to Boud Roukema for reporting the problem and discussing
the details and testing the fix.
2022-09-08 15:01:29 +03:00
Jia Tan
4d80b463a1 Build: Don't allow empty LIST in --enable-match-finders=LIST.
It's enforced only when a match finder is needed, that is,
when LZMA1 or LZMA2 encoder is enabled.
2022-07-25 18:20:01 +03:00
Lasse Collin
4773608554 Build: Enable Automake's parallel test harness.
It has been the default for quite some time already and
the old serial harness isn't discouraged. The downside is
that with parallel tests one cannot print progress info or
other diagnostics to the terminal; all output from the tests
will be in the log files only. But now that the compression
tests are separated the parallel tests will speed things up.
2022-05-23 21:31:36 +03:00
Lasse Collin
feb9c1969b Build: Bump Autoconf and Libtool version requirements.
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)
2020-02-15 15:07:11 +02:00
Lasse Collin
3d576cf921 Build: Use AM_GNU_GETTEXT_REQUIRE_VERSION and require 0.19.6.
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.
2020-02-15 15:05:35 +02:00
Lasse Collin
986d8c9b52 Build: Workaround a POSIX shell detection problem on Solaris.
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.
2020-02-05 19:33:37 +02:00
Lasse Collin
43ce4ea7c7 Scripts: Put /usr/xpg4/bin to the beginning of PATH on Solaris.
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.
2019-09-24 23:02:40 +03:00
Lasse Collin
fc77929e92 configure.ac: Fix a typo in a comment. 2019-06-25 00:16:06 +03:00
Lasse Collin
662b27c417 Update the home page URLs to HTTPS. 2017-04-19 22:17:35 +03:00
Lasse Collin
446e4318fa xz: Fix copying of timestamps on Windows.
xz used to call utime() on Windows, but its result gets lost
on close(). Using _futime() seems to work.

Thanks to Martok for reporting the bug:
http://www.mail-archive.com/xz-devel@tukaani.org/msg00261.html
2016-06-30 20:27:36 +03:00
Lasse Collin
ade31a2bfb Build: Bump GNU Gettext version requirement to 0.19.
It silences a few warnings and most people probably have
0.19 even on stable distributions.

Thanks to Christian Kujau.
2016-04-10 20:54:17 +03:00
Lasse Collin
ac398c3baf liblzma: Disable external SHA-256 by default.
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.
2016-03-13 20:21:49 +02:00
Lasse Collin
473ef0dc69 Build: Avoid SHA256_Init on FreeBSD and MINIX 3.
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.
2016-03-10 20:26:49 +02:00
Lasse Collin
c7bc20a6f3 Build: Disable xzdec, lzmadec, and lzmainfo when they cannot be built.
They all need decoder support and if that isn't available,
there's no point trying to build them.
2015-11-03 20:47:07 +02:00
Lasse Collin
5cbca1205d Build: Simplify $enable_{encoders,decoders} usage a bit. 2015-11-03 20:35:19 +02:00
Lasse Collin
cb3111e3ed xz: Make xz buildable even when encoders or decoders are disabled.
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.
2015-11-03 20:29:33 +02:00
Lasse Collin
23ed1d4148 Build: Fix configure to handle LZMA1 dependency with LZMA2.
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.
2015-11-03 17:54:48 +02:00
Lasse Collin
cbc9e39bae Build: Minor Cygwin cleanup.
Some tests used "cygwin*" and some used "cygwin". I changed
them all to use "cygwin". Shouldn't affect anything in practice.
2015-08-11 13:23:04 +03:00
Lasse Collin
bcacd8ce7a Build: Support building of MSYS2 binaries. 2015-08-11 13:21:52 +03:00
Lasse Collin
6bd0349c58 Revert "xz: Use pipe2() if available."
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.
2015-04-20 20:17:48 +03:00
Lasse Collin
1238381143 xz: Add support for sandboxing with Capsicum.
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.
2015-03-31 22:19:34 +03:00
Lasse Collin
7a11c4a8e5 xz: Use pipe2() if available. 2015-02-22 19:38:48 +02:00
Lasse Collin
7815112153 Build: POSIX shell isn't required if scripts are disabled. 2014-12-26 12:00:05 +02:00
Lasse Collin
b13a781833 Build: Replace obsolete AC_HELP_STRING with AS_HELP_STRING. 2014-11-17 18:52:21 +02:00
Lasse Collin
542cac122e Build: Fix Autoconf warnings about escaped backquotes.
Thanks to Daniel Richard G. for pointing out that it's
good to sometimes run autoreconf -fi with -Wall.
2014-11-17 18:43:19 +02:00
Lasse Collin
c923b140b2 Build: Prepare to support Automake's subdir-objects.
Due to a bug in Automake, subdir-objects won't be enabled
for now.

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17354

Thanks to Daniel Richard G. for the original patches.
2014-10-29 21:15:35 +02:00
Lasse Collin
c4911f2db3 Build: Detect supported compiler warning flags better.
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.
2014-09-25 18:38:48 +03:00
Lasse Collin
e1c8f1d01f liblzma: Add lzma_memcmplen() for fast memory comparison.
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.
2014-07-25 20:57:20 +03:00
Lasse Collin
56056571df Build: Add --disable-doc to configure. 2014-04-25 17:44:26 +03:00
Lasse Collin
6b44b4a775 Add native threading support on Windows.
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.
2013-09-17 11:52:28 +03:00
Lasse Collin
ae0ab74a88 Build: Remove a comment about Automake 1.10 from configure.ac.
The previous commit supports silent rules and that requires
Automake 1.11.
2013-09-11 14:40:35 +03:00
Lasse Collin
72975df6c8 Build: Create liblzma.pc in a src/liblzma/Makefile.am.
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.
2013-09-09 20:37:03 +03:00