This was used to detect the presence of version 3.8.0 which introduced the "su"
config option[^1]. It was releases in 2011, so I'd say it's time that we can
just assume that it's supported.
Additionally, this has a bit of a security impact as it defaults to not using
the "su" option, which means that logrotate will do more than necessary as
root. This happened with our packages as these were built without logrotate
being installed, which caused the version detection to fail. Just assuming the
new version here instead of adding it as a non-obvious build dependency should
be the more robust fix.
[^1]: https://github.com/logrotate/logrotate/blob/r3-8-0/CHANGES#L6-L8
CMake 3.4 introduced a new policy [^1] which prevents from automatically
adding the compiler flags needed for exporting the symbols of the
executables and libraries without the `ENABLE_EXPORTS` property. So, by
defining this variable, CMake will restore the previous behaviour by
automatically adding the `ENABLE_EXPORTS` properties to all targets.
[1]: https://cmake.org/cmake/help/latest/policy/CMP0065.html
CMake version `< 3.5` is no longer supported, so the new CMake minimum
policy version is set to `3.8` to support C++17 unconditionally. After
checking all the policies that might affect Icinga 2 in any way, CMake
`3.17` is used as a max supported CMake policy. Anything above that may
work but we didn't explicitly verify the policies introduced with CMake
3.18 and later and may or may not affect Icinga 2.
`override` indicates an override of a virtual method and refuses to compile in case of a signature mismatch across the inheritence hierarchy.
This is especially useful when signatures change not to forget anything. Hence, we shall always use `override` whereever applicable.
to stick to CMake pre-v3.29 behavior. CMake v3.29 introduces CPACK_WIX_INSTALL_SCOPE. Its default conflicts with the ALLUSERS property in our icinga-installer/icinga2.wixpatch.cmake.
Unfortunately, the symbol resolution of boost::stacktrace is broken on
FreeBSD, therefore fall back to using backtrace_symbols() to print the
stack trace saved by Boost.
Additionally, -D_GNU_SOURCE is required on FreeBSD for the
_Unwind_Backtrace function used by boost::stacktrace.
Older versions of MSVC fail to rethrow an unhandled C++ exception (using
`throw;`) in the termination handler (`std::set_terminate`), however
Icinga relies on this behavior in its crash handler
(`Application::ExceptionHandler`).
On case-insensitive file systems (i.e. macOS), the VERSION file collides with the Boost-provided version file on #include <version>.
Work around by re-naming VERSION to ICINGA2_VERSION.
When statically compiling icinga2 with a local boost the order of the boost libraries matters.
Correcting the order fixes the following linker issue:
```
make[5]: Entering directory `.../icinga2/icinga2-2.11.3/build'
[ 98%] Linking CXX executable ../Bin/RELEASE/icinga2
.../boost_1_72_0/lib/libboost_coroutine.a(coroutine_context.o): In function `boost::coroutines::detail::coroutine_context::coroutine_context(void (*)(boost::context::detail::transfer_t), boost::coroutines::detail::preallocated const&)':
coroutine_context.cpp:(.text+0x59): undefined reference to `make_fcontext'
.../boost_1_72_0/lib/libboost_coroutine.a(coroutine_context.o): In function `boost::coroutines::detail::coroutine_context::jump(boost::coroutines::detail::coroutine_context&, void*)':
coroutine_context.cpp:(.text+0xe8): undefined reference to `jump_fcontext'
collect2: error: ld returned 1 exit status
make[5]: *** [Bin/RELEASE/icinga2] Error 1
```
Signed-off-by: Sven Nierlein <sven@nierlein.de>
