(CommandList
  children: [
    (C {(set)} {(-e)})
    (If
      arms: [
        (if_arm
          cond: [
            (Sentence
              child: 
                (C {(Lit_Other "[")} {(-z)} 
                  {
                    (DQ 
                      (BracedVarSub
                        token: <VSub_Name CLANG_TIDY>
                        suffix_op: 
                          (StringUnary
                            op_id: VTest_ColonEquals
                            arg_word: 
                              {
                                (CommandSubPart
                                  command_list: (CommandList children:[(C {(which)} {(clang-tidy)})])
                                  left_token: <Left_CommandSub "$(">
                                  spids: [18 22]
                                )
                              }
                          )
                        spids: [15 23]
                      )
                    )
                  } {(Lit_Other "]")}
                )
              terminator: <Op_Semi ";">
            )
          ]
          action: [
            (SimpleCommand
              words: [{(echo)} {(DQ ("Unable to find clang-tidy"))}]
              redirects: [(Redir op_id:Redir_GreatAnd fd:1 arg_word:{(2)} spids:[38])]
            )
            (C {(exit)} {(1)})
          ]
          spids: [-1 29]
        )
      ]
      spids: [-1 46]
    )
    (C 
      {
        (CommandSubPart
          command_list: 
            (CommandList
              children: [
                (C {(dirname)} 
                  {
                    (DQ 
                      (BracedVarSub
                        token: <VSub_Name BASH_SOURCE>
                        bracket_op: (ArrayIndex expr:(ArithWord w:{(Lit_Digits 0)}))
                        spids: [53 58]
                      )
                    )
                  }
                )
              ]
            )
          left_token: <Left_CommandSub "$(">
          spids: [49 60]
        ) (/../cpp/generate_compilation_database.sh)
      }
    )
    (C {(DQ ($ VSub_Name "$CLANG_TIDY"))} {(-p)} 
      {
        (DQ 
          (CommandSubPart
            command_list: (CommandList children:[(C {(bazel)} {(info)} {(execution_root)})])
            left_token: <Left_CommandSub "$(">
            spids: [71 77]
          )
        )
      } {(DQ ($ VSub_At "$@"))}
    )
  ]
)