Resolve "Add option to compile out LTTng entirely"

tracetools/CMakeLists.txt

@@ -25,7 +25,11 @@ if(NOT TRACETOOLS_DISABLED)
   endif()
 endif()
 
-include_directories(include)
+# store configuration variables for runtime use
+configure_file(include/${PROJECT_NAME}/config.h.in include/${PROJECT_NAME}/config.h)
+
+# add both source and output include, to capture config.h
+include_directories(include ${PROJECT_BINARY_DIR}/include)
 
 # Status checking tool
 add_executable(status
@@ -66,6 +70,10 @@ install(
   DIRECTORY include/
   DESTINATION include
 )
+install(
+  FILES ${PROJECT_BINARY_DIR}/include/${PROJECT_NAME}/config.h
+  DESTINATION include/${PROJECT_NAME}
+)
 install(
   TARGETS ${PROJECT_NAME}
   EXPORT ${PROJECT_NAME}_export