add check ROS_DISTRO in CMAKE

Signed-off-by: Hyungyu Kim <[email protected]>

Author: GyuH13

turtlebot3_panorama/CMakeLists.txt

@@ -16,6 +16,18 @@ if(DEFINED ENV{ROS_DISTRO})
   set(ROS_DISTRO $ENV{ROS_DISTRO})
 endif()
 
+if(NOT DEFINED ROS_DISTRO OR ROS_DISTRO STREQUAL "")
+  execute_process(
+    COMMAND printenv ROS_DISTRO
+    OUTPUT_VARIABLE ROS_DISTRO
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+endif()
+
+if(NOT DEFINED ROS_DISTRO OR ROS_DISTRO STREQUAL "")
+  message(WARNING "ROS_DISTRO is not defined.")
+endif()
+
 if(ROS_DISTRO STREQUAL "humble")
   add_definitions(-DROS2_HUMBLE)
 elseif(ROS_DISTRO STREQUAL "jazzy" OR ROS_DISTRO STREQUAL "rolling")