[Openmp-commits] [openmp] [libomp] Fix hwloc include for non-standard paths (PR #184087)

[Michael Kruse via Openmp-commits]

================
@@ -189,6 +189,14 @@ else()
   set(LIBOMP_LINKER_LANGUAGE CXX)
 endif()
 if(${LIBOMP_USE_HWLOC})
+  target_include_directories(obj.omp
+                             PUBLIC
+			     "$<BUILD_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
+			     "$<INSTALL_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
+  )
+  # omp itself uses obj.omp and thus doesn't need to include hwloc headers
+  # itself. However, we want to propagate the include to consumers of omp (e.g.
+  # libompd).
----------------
Meinersbur wrote:

I see. It doesn't require special mentioning that something does not not needed, by rather why it is repeated.

```
if(${LIBOMP_USE_HWLOC})
  # Since we are using an object, the PRIVATE and INTERFACE options are split (instead of using PUBLIC): obj.omp for compiling itself, omp for propagating the options to other libraries that depend on it, e.g. libompd.
  target_include_directories(obj.omp
                             PRIVATE
			     "$<BUILD_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
			     "$<INSTALL_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
  )
  target_include_directories(omp
                             INTERFACE
			     "$<BUILD_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
			     "$<INSTALL_INTERFACE:${LIBOMP_HWLOC_INCLUDE_DIR}>"
  )
```

Consider [experimenting with](https://cmake.org/cmake/help/latest/command/target_link_libraries.html#linking-object-libraries)
```cmake
target_link_libraries(omp PUBLIC obj.omp)
```
such that a single `PUBLIC` on `obj.omp` would suffice, which gets transitively propoageted to omp's dependees.

https://github.com/llvm/llvm-project/pull/184087