QtCreator above 4.8 version is utilizing a so called "compilation database" which placed in the compile_commands.json and contains generated information.
@@ -41,3 +41,6 @@ target_wrapper.*
# QtCreator CMake
CMakeLists.txt.user*
+
+# QtCreator 4.8< compilation database
+compile_commands.json
Miklós Márton