fix: make nvtx3 bundling conditional on rmm absorption

Author: vyasr

cpp/CMakeLists.txt

@@ -1099,6 +1099,20 @@ foreach(_dep IN LISTS _absorbed_deps)
   set(_${_dep}_link ${_dep}::${_dep})
 endforeach()
 if(BUILD_SHARED_LIBS)
+  # When rmm is a static library being absorbed via whole-archive, strip nvtx3 from its public
+  # interface. We bundle nvtx3 headers directly into cudf's install tree, so consumers get them from
+  # cudf's include path without needing the nvtx3 target or find_dependency(nvtx3).
+  get_target_property(_rmm_type rmm::rmm TYPE)
+  if(_rmm_type STREQUAL "STATIC_LIBRARY")
+    get_target_property(_rmm_real rmm::rmm ALIASED_TARGET)
+    if(_rmm_real)
+      get_target_property(_rmm_libs ${_rmm_real} INTERFACE_LINK_LIBRARIES)
+      if(_rmm_libs)
+        list(REMOVE_ITEM _rmm_libs nvtx3::nvtx3-cpp)
+        set_property(TARGET ${_rmm_real} PROPERTY INTERFACE_LINK_LIBRARIES ${_rmm_libs})
+      endif()
+    endif()
+  endif()
   foreach(_dep IN LISTS _absorbed_deps)
     get_target_property(_target_type ${_dep}::${_dep} TYPE)
     if(NOT _target_type STREQUAL "STATIC_LIBRARY")

cpp/cmake/thirdparty/get_nvtx.cmake

@@ -9,12 +9,15 @@
 function(find_and_configure_nvtx)
   include(${rapids-cmake-dir}/cpm/nvtx3.cmake)
 
-  # nvtx3 headers are bundled directly into cudf's install tree, so we only need the build-side
-  # export set for configure-time target resolution. No INSTALL_EXPORT_SET — consumers get headers
-  # from cudf's include directory without needing find_dependency(nvtx3).
-  rapids_cpm_nvtx3(BUILD_EXPORT_SET cudf-exports ${CUDF_EXCLUDE_DEPS_FROM_ALL_FLAG})
+  # nvtx3 is private for cudf, but it is a public dependency of rmm. When rmm is absorbed into
+  # libcudf via whole-archive, rmm's public transitive deps (including nvtx3-cpp) are promoted into
+  # cudf's public interface. CMake's export validation requires that nvtx3-cpp be in an export set.
+  rapids_cpm_nvtx3(
+    BUILD_EXPORT_SET cudf-exports INSTALL_EXPORT_SET cudf-exports
+                                                     ${CUDF_EXCLUDE_DEPS_FROM_ALL_FLAG}
+  )
 
-  # Propagate source dir to parent scope for header installation.
+  # Propagate source dir to parent scope (needed for header installation in standalone builds)
   set(nvtx3_SOURCE_DIR
       "${nvtx3_SOURCE_DIR}"
       PARENT_SCOPE

cpp/cmake/thirdparty/get_rmm.cmake

@@ -21,17 +21,6 @@ function(find_and_configure_rmm BUILD_SHARED EXCLUDE_FROM_ALL)
     list(APPEND _rmm_args INSTALL_EXPORT_SET cudf-exports)
   endif()
   rapids_cpm_rmm(${_rmm_args} ${_exclude_flag} CPM_ARGS OPTIONS "BUILD_SHARED_LIBS ${BUILD_SHARED}")
-  # Remove nvtx3 from rmm's public interface. Since rmm is absorbed into libcudf via whole-archive
-  # and we bundle nvtx3 headers directly, consumers don't need the nvtx3 target. This prevents the
-  # absorption loop from promoting nvtx3 into cudf's installed interface.
-  get_target_property(_rmm_real_target rmm::rmm ALIASED_TARGET)
-  if(_rmm_real_target)
-    get_target_property(_rmm_iface_libs ${_rmm_real_target} INTERFACE_LINK_LIBRARIES)
-    if(_rmm_iface_libs)
-      list(REMOVE_ITEM _rmm_iface_libs nvtx3::nvtx3-cpp)
-      set_property(TARGET ${_rmm_real_target} PROPERTY INTERFACE_LINK_LIBRARIES ${_rmm_iface_libs})
-    endif()
-  endif()
 
   # If rmm was found as a pre-existing shared library (e.g. conda), we need find_dependency(rmm) in
   # the installed config even when EXCLUDE_FROM_ALL is set. EXCLUDE_FROM_ALL controls whether CPM-