Merge pull request #29 from krytarowski/netbsd-support-1

Fix build on NetBSD: Use CMake macro to detect Python executable

Author: swolchok

CMakeLists.txt

@@ -57,7 +57,7 @@ TARGET_LINK_LIBRARIES(dump_json_ast graphqlparser)
 FUNCTION(GENERATE_AST_FILE FILE_TYPE FILE_RELATIVE_PATH)
   ADD_CUSTOM_COMMAND(
     OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${FILE_RELATIVE_PATH}
-    COMMAND python ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.py ${FILE_TYPE} ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.ast > ${CMAKE_CURRENT_BINARY_DIR}/${FILE_RELATIVE_PATH}
+    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.py ${FILE_TYPE} ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.ast > ${CMAKE_CURRENT_BINARY_DIR}/${FILE_RELATIVE_PATH}
     DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.ast ${CMAKE_CURRENT_SOURCE_DIR}/ast/ast.py)
 ENDFUNCTION(GENERATE_AST_FILE)