(.text+0x20): undefined reference to `main' and undefined reference to function

Question

I am having issue getting my makefile to work without errors. The first issue i have is with an undefined reference to main. I have main in my producer.c file as a function.

Answer 1

This rule

main: producer.o consumer.o AddRemove.o
   $(COMPILER) -pthread $(CCFLAGS) -o producer.o consumer.o AddRemove.o

is wrong. It says to create a file named producer.o (with -o producer.o), but you want to create a file named main. Please excuse the shouting, but ALWAYS USE $@ TO REFERENCE THE TARGET:

main: producer.o consumer.o AddRemove.o
   $(COMPILER) -pthread $(CCFLAGS) -o $@ producer.o consumer.o AddRemove.o

As Shahbaz rightly points out, the gmake professionals would also use $^ which expands to all the prerequisites in the rule. In general, if you find yourself repeating a string or name, you're doing it wrong and should use a variable, whether one of the built-ins or one you create.

main: producer.o consumer.o AddRemove.o
   $(COMPILER) -pthread $(CCFLAGS) -o $@ $^