Usually you don't need to use the full path to libm, and it's only needed
sometimes depending on your compiler and toolchain. I typically use
something like the following to deal with both the implicit and explicit
scenarios:
include(CheckCSourceCompiles)
set(LIBM_TEST_SOURCE "#include\nfloat f; int main(){sqrt(f);return
0;}")
check_c_source_compiles("${LIBM_TEST_SOURCE}" HAVE_MATH)
if(HAVE_MATH)
set(LIBM_LIBRARIES)
else()
set(CMAKE_REQUIRED_LIBRARIES m)
check_c_source_compiles("${LIBM_TEST_SOURCE}" HAVE_LIBM_MATH)
unset(CMAKE_REQUIRED_LIBRARIES)
if(NOT HAVE_LIBM_MATH)
message(FATAL_ERROR "Unable to use C math library functions")
endif()
set(LIBM_LIBRARIES m)
endif()
target_link_libraries(fooTarget PRIVATE ${LIBM_LIBRARIES})
--
Chuck Atkins
Staff R&D Engineer, Scientific Computing
Kitware, Inc.
On Fri, Mar 15, 2019 at 7:46 AM frodak17 wrote:
>
>
> On Thu, Mar 14, 2019 at 8:53 PM workbe...@gmx.at wrote:
>
>> Hi everyone,
>>
>> i'm searching for a way to find the right include dir so that -lm can be
>> found, the is not find_package for this, is /usr/lib and /usr/include a
>> default because he find it without me adding any include or lib path for
>> the build.
>>
>>
>>
> It seems strange that you need to do this. In my experience 'm' is just
> the math portion of the 'c' library. Depending on which host and toolset
> you are using there can be multiple version of the 'm' library depending on
> target architecture and other options used. The linker should just use the
> correct 'm' library just as it uses the correct 'c' library. It could be
> in /usr/lib depending on how the compiler was packaged for your host.
> --
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Please keep messages on-topic and check the CMake FAQ at:
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information on each offering, please visit:
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