Summary:
The `GenericDeviceTy::dataDelete` method doesn't verify the
`TargetAllocTy` of the of the device pointer. Because of this, it can
use the `MemoryManager` to free the ptr. However, the
`TARGET_ALLOC_HOST` and `TARGET_ALLOC_SHARED` types are not allocated
using the `MemoryManager` in the `GenericDeviceTy::dataAlloc` method.
Since the `MemoryManager` uses the `DeviceAllocatorTy::free` operation
without specifying the type of the ptr, some plugins may use incorrect
operations to free ptrs of certain types. In particular, this bug causes
the CUDA plugin to use the `cuMemFree` operation on ptrs of type
`TARGET_ALLOC_HOST`, resulting in an unchecked error, as shown in the
output snippet of the test
`offload/test/api/omp_host_pinned_memory_alloc.c`:
```
omptarget --> Notifying about an unmapping: HstPtr=0x00007c6114200000
omptarget --> Call to llvm_omp_target_free_host for device 0 and address 0x00007c6114200000
omptarget --> Call to omp_get_num_devices returning 1
omptarget --> Call to omp_get_initial_device returning 1
PluginInterface --> MemoryManagerTy:🆓 target memory 0x00007c6114200000.
PluginInterface --> Cannot find its node. Delete it on device directly.
TARGET CUDA RTL --> Failure to free memory: Error in cuMemFree[Host]: invalid argument
omptarget --> omp_target_free deallocated device ptr
```
This patch fixes this by adding the check of the device pointer type
before calling the appropriate operation for each type.
In a nutshell, this moves our libomptarget code to populate the offload
subproject.
With this commit, users need to enable the new LLVM/Offload subproject
as a runtime in their cmake configuration.
No further changes are expected for downstream code.
Tests and other components still depend on OpenMP and have also not been
renamed. The results below are for a build in which OpenMP and Offload
are enabled runtimes. In addition to the pure `git mv`, we needed to
adjust some CMake files. Nothing is intended to change semantics.
```
ninja check-offload
```
Works with the X86 and AMDGPU offload tests
```
ninja check-openmp
```
Still works but doesn't build offload tests anymore.
```
ls install/lib
```
Shows all expected libraries, incl.
- `libomptarget.devicertl.a`
- `libomptarget-nvptx-sm_90.bc`
- `libomptarget.rtl.amdgpu.so` -> `libomptarget.rtl.amdgpu.so.18git`
- `libomptarget.so` -> `libomptarget.so.18git`
Fixes: https://github.com/llvm/llvm-project/issues/75124
---------
Co-authored-by: Saiyedul Islam <Saiyedul.Islam@amd.com>
