makefile target-specific changing srcs files - makefile

Question

I'm trying to write a Makefile with a rule to make the project with another main.cpp file, because I'm testing my code with different options
I have different versions of the main function, that I put inside differents files : main.cpp, main_1.cpp, main_2.cpp, ..., to test different versions of my code, and they all have the same dependencies
first I was just commenting and un-commenting the Makefile variable MAIN that define the main.cpp file, but I was hoping there is a way to choose the one I want to try with a specific rule ?
I tried something with target-specific variables but it didn't work :
# # # # # # #
# VARIABLES #
# # # # # # #
NAME = my_program
VPATH = srcs
CXX = c++
CXXFLAGS = -I ./headers
OBJS = $(SRCS:%.cpp=%.o)
MAIN = main.cpp
#MAIN = main_1.cpp
SRCS = $(MAIN) file.cpp
# # # # #
# RULES #
# # # # #
all: $(NAME)
# target-specific variables
test-1: MAIN = main_1.cpp
test-1: re
$(NAME) : $(OBJS)
$(CXX) $(OBJS) -o $(NAME)
clean:
rm -f $(OBJS)
fclean: clean
rm -f $(NAME)
re: fclean all
.PHONY : all clean fclean re
the error output for main test_1 is :
c++ -I ./headers -c -o main.o srcs/main.cpp
c++ -I ./headers -c -o file.o srcs/file.cpp
c++ main_1.o Webserv.o -o my_program
c++: error: main_1.o: No such file or directory
Makefile:21: recipe for target 'my_program' failed
make: *** [my_program] Error 1
I think, then, that target-specific is not the right tool for what I'm trying to do.
Does Make provide a way to accomplish that (modifying the list of srcs files when calling a specific rule, and having the compilation working great with the new srcs files) ?

Answer 1

I'm vaguely thinking something like this.
test-%: main_%.cpp file.cpp
Now, make test-1 will produce an executable with that name from main_1.cpp instead of main.cpp, and similarly test-2 from main_2.cpp, etc.
If you have subsequent targets which hardcode my_program which should actually depend on which version you made, this might not be suitable, or at a minimum, you'd have to refactor those to use the current output executable. Similarly, you might want to add test-[1-9] to the files to remove in the clean target (or perhaps add a realclean target to remove them too).
Tangentially, several of your make variables don't seem to serve any immediate purpose. Putting stuff in variables makes sense for things you want to be able to override at compile time, or vaguely for making a general-purpose Makefile which can be applied with only minor modifications across several projects; but in isolation, these seem like unnecessary complexities you should probably avoid for the time being.
Your immediate problem could perhaps be solved by refactoring the dependency chain, but on the whole, I'd recommend keeping it as simple as possible. make already knows how to compile common source formats; all you really need to put in the Makefile are the dependencies which are not trivially obvious and any .PHONY targets, and overrides to select e.g. a specific default action.