Add in-tree oneTBB build

CMakeLists.txt

@@ -71,6 +71,25 @@ hint_flag(CXX_EXTRA_LINKER_FLAGS "
 # Honor user's CXX_EXTRA_LINK_FLAGS
 set(CXX_EXTRA_LINK_FLAGS ${CXX_EXTRA_FLAGS} ${CXX_EXTRA_LINK_FLAGS})
 
+option(USE_TBB "Enable oneTBB library for *supported* models. Enabling this on models that
+                don't explicitly link against TBB is a no-op, see description of your selected
+                model on how this is used." OFF)
+
+if (USE_TBB)
+    include(FetchContent)
+    FetchContent_Declare(
+            TBB
+            GIT_REPOSITORY https://github.com/oneapi-src/oneTBB.git
+            GIT_TAG faaf43c4ab22cb4b4267d65d5e218fa58800eea8
+    )
+    # Not using FetchContent_MakeAvailable because we need EXCLUDE_FROM_ALL
+    FetchContent_GetProperties(TBB)
+    if (NOT TBB_POPULATED)
+        FetchContent_Populate(TBB)
+        add_subdirectory(${tbb_SOURCE_DIR} ${tbb_BINARY_DIR} EXCLUDE_FROM_ALL)
+    endif ()
+endif ()
+
 # include our macros
 include(cmake/register_models.cmake)
 

src/std-data/model.cmake

@@ -23,6 +23,10 @@ register_flag_optional(NVHPC_OFFLOAD
            ccall - Compile for all supported compute capabilities"
         "")
 
+register_flag_optional(USE_TBB
+        "No-op if ONE_TBB_DIR is set. Link against an in-tree oneTBB via FetchContent_Declare, see top level CMakeLists.txt for details."
+        "OFF")
+
 macro(setup)
     set(CMAKE_CXX_STANDARD 17)
 
@@ -35,5 +39,7 @@ macro(setup)
     if(USE_VECTOR)
         register_definitions(USE_VECTOR)
     endif()
-
+    if (USE_TBB)
+        register_link_library(TBB::tbb)
+    endif ()
 endmacro()

src/std-indices/model.cmake

@@ -23,6 +23,11 @@ register_flag_optional(NVHPC_OFFLOAD
            ccall - Compile for all supported compute capabilities"
         "")
 
+register_flag_optional(USE_TBB
+        "Link against an in-tree oneTBB via FetchContent_Declare, see top level CMakeLists.txt for details."
+        "OFF")
+
+
 macro(setup)
     set(CMAKE_CXX_STANDARD 17)
 
@@ -35,5 +40,7 @@ macro(setup)
     if(USE_VECTOR)
         register_definitions(USE_VECTOR)
     endif()
-
+    if (USE_TBB)
+        register_link_library(TBB::tbb)
+    endif ()
 endmacro()

src/std-ranges/model.cmake

@@ -7,6 +7,10 @@ register_flag_optional(USE_VECTOR
         "Whether to use std::vector<T> for storage or use aligned_alloc. C++ vectors are *zero* initialised where as aligned_alloc is uninitialised before first use."
         "OFF")
 
+register_flag_optional(USE_TBB
+        "No-op if ONE_TBB_DIR is set. Link against an in-tree oneTBB via FetchContent_Declare, see top level CMakeLists.txt for details."
+        "OFF")
+
 macro(setup)
 
     # TODO this needs to eventually be removed when CMake adds proper C++20 support or at least update the flag used here
@@ -20,4 +24,7 @@ macro(setup)
     if(USE_VECTOR)
         register_definitions(USE_VECTOR)
     endif()
+    if (USE_TBB)
+        register_link_library(TBB::tbb)
+    endif ()
 endmacro()

src/tbb/model.cmake

@@ -19,15 +19,20 @@ register_flag_optional(USE_VECTOR
         "Whether to use std::vector<T> for storage or use aligned_alloc. C++ vectors are *zero* initialised where as aligned_alloc is uninitialised before first use."
         "OFF")
 
+register_flag_optional(USE_TBB
+        "No-op if ONE_TBB_DIR is set. Link against an in-tree oneTBB via FetchContent_Declare, see top level CMakeLists.txt for details."
+        "OFF")
+
 macro(setup)
     if(ONE_TBB_DIR)
         set(TBB_ROOT "${ONE_TBB_DIR}") # see https://github.com/Kitware/VTK/blob/0a31a9a3c1531ae238ac96a372fec4be42282863/CMake/FindTBB.cmake#L34
         # docs on Intel's website refers to TBB_DIR which is not correct
+        find_package(TBB REQUIRED)
     endif()
 
+    # No need to handle USE_TBB as both ONE_TBB_DIR and USE_TBB will create the TBB::tbb target
 
     # see https://github.com/oneapi-src/oneTBB/blob/master/cmake/README.md#tbbconfig---integration-of-binary-packages
-    find_package(TBB REQUIRED)
     register_link_library(TBB::tbb)
     register_definitions(PARTITIONER_${PARTITIONER})
     if(USE_VECTOR)