How to solve redefinition of main in makefile - c++

Question

I am trying to compile and link three files into an executable with a makefile, but seem to have redefined main or somehow goofed the compile/link process. The project is for a class, where the objective is to implement a linear feedback shift register, but we have to use a makefile.
Where have I redefined main? How do I alter my makefile to create my executable? I notice the error points to test.o as having redefined main, but I'm not sure why or how.
Error:
g++ -c main.cpp LFSR.cpp -Wall -Werror -ansi -pedantic
g++ -c test.cpp -Wall -Werror -ansi -pedantic
g++ main.o LFSR.o test.o -o ps2a -lboost_unit_test_framework
test.o: In function `main':
test.cpp:(.text+0xa3): multiple definition of `main'
main.o:main.cpp:(.text+0x0): first defined here
collect2: error: ld returned 1 exit status
Makefile:4: recipe for target 'ps2a' failed
make: *** [ps2a] Error 1
My makefile:
all: ps2a
ps2a: main.o LFSR.o test.o
g++ main.o LFSR.o test.o -o ps2a -lboost_unit_test_framework
LFSR.o: LFSR.cpp LFSR.hpp
g++ -c LFSR.cpp -Wall -Werror -ansi -pedantic
main.o: main.cpp LFSR.hpp
g++ -c main.cpp LFSR.cpp -Wall -Werror -ansi -pedantic
test.o: test.cpp
g++ -c test.cpp -Wall -Werror -ansi -pedantic
clean:
rm *.o ps2a
main.cpp:
#include "LFSR.hpp"
int main(){
}
LFSR.hpp
#include <string>
#include <iostream>
class LFSR{
public:
LFSR(std::string, int);
int step();
int generate(int k);
private:
std::string bitString;
int tapPos;
};
LFSR.cpp:
#include "LFSR.hpp"
void makeBitStringValid(std::string& str);
LFSR::LFSR(std::string str, int t){
}
int LFSR::step(){
return 0;
}
int LFSR::generate(int k){
return 0;
}
void makeBitStringValid(std::string& str){
}
test.cpp (Note, this is given by the instructor-- I'm not entirely sure how it works yet)
#include <iostream>
#include <string>
#include "LFSR.hpp"
#define BOOST_TEST_DYN_LINK
#define BOOST_TEST_MODULE Main
#include <boost/test/unit_test.hpp>
BOOST_AUTO_TEST_CASE(fiveBitsTapAtTwo) {
LFSR l("00111", 2);
BOOST_REQUIRE(l.step() == 1);
BOOST_REQUIRE(l.step() == 1);
BOOST_REQUIRE(l.step() == 0);
BOOST_REQUIRE(l.step() == 0);
BOOST_REQUIRE(l.step() == 0);
BOOST_REQUIRE(l.step() == 1);
BOOST_REQUIRE(l.step() == 1);
BOOST_REQUIRE(l.step() == 0);
LFSR l2("00111", 2);
BOOST_REQUIRE(l2.generate(8) == 198);
}

Answer 1

Do not provide own main because The Boost Unit Test Framework already provides one in your test.cpp with the lines:
#define BOOST_TEST_DYN_LINK
#define BOOST_TEST_MODULE Main
#include <boost/test/unit_test.hpp>
Dynamic library variant of the UTF
Unlike the static library variant function main() can't reside in the
dynamic library body. Instead this variant supplies default function
main() implementation as part of the header boost/test/unit_test.hpp
to be generated as part of your test file body. The function main() is
generated only if either the BOOST_TEST_MAIN or the BOOST_TEST_MODULE
flags are defined during a test module compilation. For single-file
test module flags can be defined either in a test module's makefile or
before the header boost/test/unit_test.hpp inclusion. For a multi-file
test module flags can't be defined in makefile and have to be defined
in only one of the test files to avoid duplicate copies of the
function main().