Only add CppCheck target if this is the main project

Author: Omegastick

CMakeLists.txt

@@ -9,31 +9,33 @@ project(CppRl
 set(CMAKE_CXX_STANDARD 17)
 
 # Cppcheck
-list(APPEND CPPCHECK_ARGS
-    --enable=warning
-    --std=c++14
-    --force
-    --verbose
-    --quiet
-    --inline-suppr
-    --error-exitcode=1
-    --language=c++
-    --config-exclude=${CMAKE_CURRENT_LIST_DIR}/src/third_party
-    --config-exclude=${CMAKE_CURRENT_LIST_DIR}/lib
-    -i${CMAKE_CURRENT_LIST_DIR}/example/lib
-    --suppressions-list=${CMAKE_CURRENT_LIST_DIR}/CppCheckSuppressions.txt 
-    -I ${CMAKE_CURRENT_LIST_DIR}/src 
-    -I ${CMAKE_CURRENT_LIST_DIR}/include 
-    -I ${CMAKE_CURRENT_LIST_DIR}/example 
-    ${CMAKE_CURRENT_LIST_DIR}/src
-    ${CMAKE_CURRENT_LIST_DIR}/example
-)
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    list(APPEND CPPCHECK_ARGS
+        --enable=warning
+        --std=c++14
+        --force
+        --verbose
+        --quiet
+        --inline-suppr
+        --error-exitcode=1
+        --language=c++
+        --config-exclude=${CMAKE_CURRENT_LIST_DIR}/src/third_party
+        --config-exclude=${CMAKE_CURRENT_LIST_DIR}/lib
+        -i${CMAKE_CURRENT_LIST_DIR}/example/lib
+        --suppressions-list=${CMAKE_CURRENT_LIST_DIR}/CppCheckSuppressions.txt 
+        -I ${CMAKE_CURRENT_LIST_DIR}/src 
+        -I ${CMAKE_CURRENT_LIST_DIR}/include 
+        -I ${CMAKE_CURRENT_LIST_DIR}/example 
+        ${CMAKE_CURRENT_LIST_DIR}/src
+        ${CMAKE_CURRENT_LIST_DIR}/example
+    )
 
-add_custom_target(
-    check
-    COMMAND cppcheck ${CPPCHECK_ARGS}
-    COMMENT "Running Cppcheck"
-)
+    add_custom_target(
+        check
+        COMMAND cppcheck ${CPPCHECK_ARGS}
+        COMMENT "Running Cppcheck"
+    )
+endif(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 
 # Dependencies
 ## PyTorch