Thrust Usage Update, main branch (2024.12.02.) #790
Conversation
Instead of setting up a single traccc::Thrust target that would take care of everything related to Thrust, the code rather sets up traccc::Thrust in a way that allows very little access in traccc::core to Thrust. Instead, traccc::cuda and traccc::sycl (and also traccc_test_cuda) privately link against Thrust in specific ways. So that the appropriate "device headers" would get included everywhere.
krasznaa
added
build
|
| thrust_create_target( traccc::cuda_thrust | ||
| HOST CPP | ||
| DEVICE CUDA ) | ||
| target_link_libraries( traccc_cuda | ||
| PRIVATE traccc::cuda_thrust ) |
There was a problem hiding this comment.
Out of curiosity, if you link a target against multiple of these Thrust libraries, what happens? Does it give an error at configuration time or does it cause include ambiguities? 🤔
There was a problem hiding this comment.
I'm desperately trying to find it in the code, but don't remember all the details anymore. 😦
I think the issue comes from the specific Thrust targets setting some custom target properties on themselves. See:
If I remember correctly what I saw was that in case a target ends up being linked against let's say both Thrust::CPP::Device and Thrust::CUDA::Device, then CMake freaks out during the build system generation stage. Stating that the value of THRUST_INTERFACE_DEVICE couldn't be determined for the user's target. Or something like that.
But definitely, already during the CMake configuration one gets an error if trying to link against multiple "host" or "device" libraries at the same time. This is why traccc::Thrust is set up in this hacky way now. That I really can't use thrust_create_target(...) to make a target that would be appropriate for traccc::core. 😦
Changed how Thrust would be used in the build.
Instead of setting up a single
traccc::Thrusttarget that would take care of everything related to Thrust, the code rather sets uptraccc::Thrustin a way that allows very little access intraccc::coreto Thrust.Instead,
traccc::cudaandtraccc::sycl(and alsotraccc_test_cuda) privately link against Thrust in specific ways. So that the appropriate "device headers" would get included everywhere.Note that this shall not only help the SYCL developments (the commit comes directly from #773...), but the HIP ones as well. (Pinging @flg and @StewMH.)