Question

I am trying to write a makefile for a small scale application I wrote in C under Linux. Currently all my source files .c are in the top level directory and all header files in
an include directory. Here is the makefile I used for this.

IDIR =include
CC=gcc
CFLAGS=-I$(IDIR)


ODIR=obj

_OBJ = main.o kernel.o user_app.o myargs.o ofp_msgs.o pkt_ip.o pkt_ether.o pkt_tcp.o pkt_udp.o pkt_icmp.o 
OBJ = $(patsubst %,$(ODIR)/%,$(_OBJ))

#DEPS = ofp_msgs.h




$(ODIR)/%.o: %.c 
    $(CC) -c -o $@ $< $(CFLAGS)            
all: jam

jam: $(OBJ)
    gcc -o $@ $^ $(CFLAGS)  -lpthread

.PHONY: clean

clean:
    rm -f $(ODIR)/*.o *~ jam 

It works fine but what I want is that for example I make a sub directory called "Packet" and all my packet parsing files i-e "pkt_ip.c, pkt_tcp.c etc" should be in that directory where as their header files should still be in the top level directory i-t "toplevel/include". I did a bit of search and the most common way was to use recursive make. Then I see a lots of pages complaining about recursive make. Can anyone please help me in this as how to do this right ?
Thanks

Answer 1

there are several ways to do this but you can certainly use VPATH:=Packet to tell make to look for source files inside the ‘Packet’ directory. see make manual