Boost iostream uses `find_package` in quiet mode and then again uses
`find_package` with required. This second call triggers a
`add_library cannot create imported target "LibLZMA::LibLZMA"
because another target with the same name already exists.`
This can simply be fixed by skipping the alias part on secondary
`find_package` runs.
(cherry picked from commit d04eb78ab3)
This is combined from the following commits in the master branch:
443dfebced6b117d3b1f5e34774c31
Thanks to Iouri Kharon for the bug report, the original patch,
and testing.
The command line tools cannot be built with MSVC for now but
they can be built with MinGW-w64.
Thanks to Iouri Kharon for the bug report and the original patch.
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
The previous commit split liblzma.map into liblzma_linux.map and
liblzma_generic.map. This commit updates the CMake build for those.
common_w32res.rc dependency was listed under Linux/FreeBSD while
obviously it belongs to Windows when building a DLL.
These are a minor thing especially since the xz build has
some real problems still like lack of large file support
on 32-bit systems but I'll commit this since the code exists.
Thanks to Jia Tan.
The naming conflict with FindLibLZMA module gets worse.
Not avoiding it in the first place was stupid.
Normally find_package(LibLZMA) will use the module and
find_package(liblzma 5.2.5 REQUIRED CONFIG) will use the config
file even with a case insensitive file system. However, if
CMAKE_FIND_PACKAGE_PREFER_CONFIG is TRUE and the file system
is case insensitive, find_package(LibLZMA) will find our liblzma
config file instead of using FindLibLZMA module.
One big problem with this is that FindLibLZMA uses
LibLZMA::LibLZMA and we use liblzma::liblzma as the target
name. With target names CMake happens to be case sensitive.
To workaround this, this commit adds
add_library(LibLZMA::LibLZMA ALIAS liblzma::liblzma)
to the config file. Then both spellings work.
To make the behavior consistent between case sensitive and
insensitive file systems, the config and related files are
renamed from liblzmaConfig.cmake to liblzma-config.cmake style.
With this style CMake looks for lowercase version of the package
name so find_package(LiBLzmA 5.2.5 REQUIRED CONFIG) will work
to find our config file.
There are other differences between our config file and
FindLibLZMA so it's still possible that things break for
reasons other than the spelling of the target name. Hopefully
those situations aren't too common.
When the config file is available, it should always give as good or
better results as FindLibLZMA so this commit doesn't affect the
recommendation to use find_package(liblzma 5.2.5 REQUIRED CONFIG)
which explicitly avoids FindLibLZMA.
Thanks to Markus Rickert.
The syntax "if(DEFINED CACHE{FOO})" requires CMake 3.14.
In some other places the code treats the cache variables
like normal variables already (${FOO} or if(FOO) is used,
not ${CACHE{FOO}).
Thanks to ygrek for reporting the bug on IRC.
This version matches CMake files in the master branch (commit
265daa873c) except that this omits
two source files that aren't in v5.2 and in the beginning of
CMakeLists.txt the first paragraph in the comment is slightly
different to point out possible issues in building shared liblzma.
Benjamin Buch
Lasse Collin
Jia Tan
huangqinjin