remove SeQuant's FindTBB (very very legacy at this point) and adapt u…

…ses to the most recent FindTBB in VG cmake kit

CMakeLists.txt

@@ -107,10 +107,13 @@ find_package(Threads REQUIRED)
 # PSTL (used by g++-9 and clang++-8 in c++17 mode) needs TBB
 if ((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU" AND
         ${CMAKE_CXX_COMPILER_VERSION} VERSION_GREATER 9) OR
-(${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang" AND
+    (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang" AND
         ${CMAKE_CXX_COMPILER_VERSION} VERSION_GREATER 8))
     if (ENABLE_TBB)  # but user must enable the search for TBB since this is an additional source of build entropy
         find_package(TBB REQUIRED)
+        # TBB::tbb by default is not GLOBAL, so to allow users of LINALG_LIBRARIES to safely use it we need to make it global
+        # more discussion here: https://gitlab.kitware.com/cmake/cmake/-/issues/17256
+        set_target_properties(TBB::tbb PROPERTIES IMPORTED_GLOBAL TRUE)
     endif (ENABLE_TBB)
 endif ()
 # check of <execution> header is usable

cmake/modules/CheckCXXFeatures.cmake

@@ -8,16 +8,15 @@ macro(check_cxx_execution_header _prefix)
   # compilation checks
   ##############################################
   set(_prereq_list "_STANDALONE")
-  if (TBB_FOUND)
+  if (TARGET TBB::tbb)
     list(APPEND _prereq_list _WITH_TBB)
-  endif (TBB_FOUND)
+  endif ()
 
   foreach (_prereq ${_prereq_list})
     cmake_push_check_state()
 
     if (_prereq STREQUAL _WITH_TBB)
-      list(APPEND CMAKE_REQUIRED_LIBRARIES ${TBB_LIBRARIES})
-      list(APPEND CMAKE_REQUIRED_INCLUDES ${TBB_INCLUDE_DIRS})
+      list(APPEND CMAKE_REQUIRED_LIBRARIES TBB::tbb)
     endif ()
 
     CHECK_CXX_SOURCE_COMPILES(