Undefined reference or unresolved external symbol

stackoverflow What is an undefined reference/unresolved external symbol error and how do I fix it?

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stackoverflow c++ undefined symbol when compiling

TODO

https://stackoverflow.com/questions/14557657/linker-error-c-undefined-reference

https://stackoverflow.com/questions/143530/linker-woes-undefined-reference

https://blog.csdn.net/huangbo1221/article/details/53438598

https://latedev.wordpress.com/2014/04/22/common-c-error-messages-2-unresolved-reference/

https://visualgdb.com/tutorials/linux/libraries/diagnosing/

https://www.linuxquestions.org/questions/programming-9/shared-library-error-undefined-reference-215785/

https://stackoverflow.com/questions/12748837/c-shared-library-undefined-reference-to-fooclasssayhello

draft

undefined symbol: _ZN9CppCelery11PredictTask4NAMEE (./libfsc_quote_predict.so)

VPATH = .:../core:../core/celery

PREFIX := ..

INC = -I. -I.. -I../hundsun -I../third_party
SRCS := $(wildcard *.cpp)
SRCS += $(wildcard ../core/*.cpp)
SRCS += $(wildcard ../core/celery/*.cpp)
OBJS := $(patsubst %.cpp,%.o,$(SRCS))
TARGET := libfsc_quote_predict.so
LIBS = -lalgo_public -lh5api -lhiredis -lcurl

include ../make/master.mk

VPATH = .:../core:../core/celery

PREFIX := ..

INC = -I. -I.. -I../hundsun -I../third_party
SRCS := $(wildcard *.cpp)
SRCS += $(wildcard ../core/*.cpp)

OBJS := $(patsubst %.cpp,%.o,$(SRCS))
TARGET := libfsc_quote_predict.so
LIBS = -lalgo_public -lh5api -lhiredis -lcurl

include ../make/master.mk

使用上述第二个makefile进行编译，生成的so就会有标题中描述的undefined symbol错误。显然编译过程是没有错误的。通过查看代码，我猜测应该是文件../core/celery/tasks.cpp没有被编译到so中，从而导致了上述undefined symbol的错误。