gcc makefile error: "No rule to make target ..."

Question

I'm trying to use GCC (linux) with a makefile to compile my project.

I get the following error which is can't seem to decipher in this context:
"No rule to make target vertex.cpp', needed by vertex.o'. Stop."

This is the makefile:

a.out: vertex.o edge.o elist.o main.o vlist.o enode.o vnode.o
    g++ vertex.o edge.o elist.o main.o vlist.o enode.o vnode.o

main.o: main.cpp main.h
    g++ -c main.cpp

vertex.o: vertex.cpp vertex.h
    g++ -c vertex.cpp

edge.o: edge.cpp edge.h
    g++ -c num.cpp

vlist.o: vlist.cpp vlist.h
    g++ -c vlist.cpp

elist.o: elist.cpp elist.h
    g++ -c elist.cpp

vnode.o: vnode.cpp vnode.h
    g++ -c vnode.cpp

enode.o: enode.cpp enode.h
    g++ -c node.cpp

Answer 1

That's usually because you don't have a file called vertex.cpp available to make. Check that:

• that file exists.
• you're in the right directory when you make.

Other than that, I've not much else to suggest. Perhaps you could give us a directory listing of that directory.

Answer 2

Is that it exactly? Remember that Makefile syntax is whitespace aware and requires tabs to indent commands under actions.

Answer 3

The more common reason for this message to be printed is because you forgot to include the directory in which the source file resides. As a result, gcc "thinks" this file does not exist.

You can add the directory using the -I argument to gcc.