CMake build doesn't disable the Windows autolink feature

[jtytgat]

When using the CMake build for the process component of Boost on Windows, the autolink feature is still active (using process v2 API), resulting in a link error:

LINK : fatal error LNK1104: cannot open file 'boost_process-vc143-mt-gd-x64-1_89.lib'

Using boost 1.89 release but I believe the problem is still present currently, i.e. autolink is active for CMake builds.

When comparing the CMakeLists.txt of Boost process with e.g. filesystem or url we don't have a BOOST_<COMPONENT>_NO_LIB define in Boost process:

url:
--8<--
function(boost_url_setup_properties target)
target_compile_features(${target} PUBLIC cxx_constexpr)
target_compile_definitions(${target} PUBLIC BOOST_URL_NO_LIB=1)
--8<--

filesystem:
--8<--
target_compile_definitions(boost_filesystem
PUBLIC
# NOTE:
# We deactivate autolinking, because cmake based builds don't need it
# and we don't implement name mangling for the library file anyway.
# Ususally the parent CMakeLists.txt file should already have globally defined BOOST_ALL_NO_LIB
BOOST_FILESYSTEM_NO_LIB
$&lt;$&lt;STREQUAL:$<TARGET_PROPERTY:boost_filesystem,TYPE>,SHARED_LIBRARY>:BOOST_FILESYSTEM_DYN_LINK=1>
$&lt;$&lt;STREQUAL:$<TARGET_PROPERTY:boost_filesystem,TYPE>,STATIC_LIBRARY>:BOOST_FILESYSTEM_STATIC_LINK=1>
PRIVATE
BOOST_FILESYSTEM_SOURCE
)
--8<--

Changing in process' CMakeLists.txt from...

--8<--
target_compile_definitions(boost_process
PRIVATE BOOST_PROCESS_SOURCE=1
)
--8<--
to...
--8<--
target_compile_definitions(boost_process
PUBLIC BOOST_PROCESS_NO_LIB
PRIVATE BOOST_PROCESS_SOURCE=1
)
--8<--

...solves the problem as it disables the autolink features.

[klemens-morgenstern]

Can you submit a PR?