g ++如何使用make？

Question

I have this makefile

CC = g++
CFLAGS = -std=c++14 -Wall -Wpedantic -g
PROG = a
OBJS = other.o main.o
SRCS = other.cpp main.cpp

a: $(OBJS)
    $(CC) $(CFLAGS) -o $(PROG) $(OBJS)

.cpp.o:
    $(CC) $(CFLAGS) -c $*.cpp

clean:
    $(RM) -f $(OBJS) $(PROG)

depend:
    makedepend -- $(CFLAGS) -- $(SRCS)

My other.cpp is

int f( ) noexcept // example function
{
    return 2;
}

My main.cpp is

int main( int, char** )
{
    f( );
    return 0;
}

So, obviously, When I run make depend , it only adds a line that says #DO NOT DELETE . However, upon compilation, when i run just make , i get this error for main.cpp: 'f' was not declared in this scope . I think I'm missing something big here. Can anyone explain why this doesn't compile and what I should do?

Answer 1

This has nothing to do with your Makefile.

The compiler's error message is self-explanatory. Functions must be declared before they are used, in C++.

Add a proper declaration:

int f() noexcept;

To your main.cpp .