单片机新手求助该警告怎么消除*** WARNING L1:

fe2c9019d1dc3749

• 2020-06-09

*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL    SYMBOL:  _SENDCHAR    MODULE:  main1051.obj (MAIN1051)*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL    SYMBOL:  INIT    MODULE:  main1051.obj (MAIN1051)*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL    SYMBOL:  COMBUF    MODULE:  main1051.obj (MAIN1051)*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  INIT    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0801H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0806H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 080DH*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMBUF    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 081AH*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMBUF    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0821H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0823H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0830H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMBUF    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0834H*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  _SENDCHAR    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 083BH*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL    SYMBOL:  COMPOINTER    MODULE:  main1051.obj (MAIN1051)    ADDRESS: 0843H