1 files changed, 30 insertions, 23 deletions
diff --git a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
index 8e04f97492..54cecf812d 100644
--- a/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step9/MathFunctions/CMakeLists.txt
@@ -1,34 +1,41 @@
-# first we add the executable that generates the table
-add_executable(MakeTable MakeTable.cxx)
-
-# add the command to generate the source code
-add_custom_command(
-  OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-  DEPENDS MakeTable
-  )
-
-# add the main library
-add_library(MathFunctions
-            mysqrt.cxx
-            ${CMAKE_CURRENT_BINARY_DIR}/Table.h
-            )
+add_library(MathFunctions MathFunctions.cxx)
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
-# state that we depend on Tutorial_BINARY_DIR but consumers don't, as the
-# TutorialConfig.h include is an implementation detail
-# state that we depend on our binary dir to find Table.h
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          PRIVATE   ${CMAKE_CURRENT_BINARY_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
-# link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # generate Table.h
+  include(MakeTable.cmake)
+
+  # library that just does sqrt
+  add_library(SqrtLibrary STATIC
+              mysqrt.cxx
+              ${CMAKE_CURRENT_BINARY_DIR}/Table.h
+              )
+
+  # state that we depend on our binary dir to find Table.h
+  target_include_directories(SqrtLibrary PRIVATE
+                             ${CMAKE_CURRENT_BINARY_DIR}
+                             )
+
+  target_link_libraries(SqrtLibrary PUBLIC tutorial_compiler_flags)
+  target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
+endif()
+
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
+if(TARGET SqrtLibrary)
+  list(APPEND installable_libs SqrtLibrary)
+endif()
 install(TARGETS ${installable_libs} DESTINATION lib)
 # install include headers
 install(FILES MathFunctions.h DESTINATION include)