basic make file

cyb0rg777 · 09-28-2005, 09:59 PM

I have 6 source files. Right now they are included as .h files.My make file looks like this.

Code:

all: mygame

mygame:mygame.o  
	g++ -g `sdl-config --libs` mygame.o -o mygame -lSDL_image -lSDL_mixer

mygame.o:mygame.cpp
	g++ -g -c `sdl-config --cflags` mygame.cpp

This works fine until I edit one of my .h files then I have to resave my main file to recompile.This is what I want to do.

Code:

all: mygame

mygame:mygame.o  scroll.o character.o utilities.o sprites.o
	g++ -g `sdl-config --libs` mygame.o  scroll.o character.o utilities.o sprites.o -o mygame -lSDL_image -lSDL_mixer

mygame.o:mygame.cpp
	g++ -g -c `sdl-config --cflags` mygame.cpp
scroll.o:scroll.cpp
	g++ -g -c `sdl-config --cflags` scroll.cpp
character.o:character.cpp
	g++ -g -c `sdl-config --cflags` character.cpp
utilities.o:utilities.cpp
	g++ -g -c `sdl-config --cflags` utilities.cpp
sprites.o:sprites.cpp
	g++ -g -c `sdl-config --cflags` sprites.cpp

But when I run this I get unresolved reference.Either I'm doing something wrong or I'm missing the point .What good is linking .cpp files if you can't access the functions and data types?
Please dumb it down for me.

CroMagnon · 09-29-2005, 12:38 AM

Quote:

This works fine until I edit one of my .h files then I have to resave my main file to recompile.

What you should do is make your .h files part of the dependency list...

Code:

all: mygame

mygame:mygame.o  
g++ -g `sdl-config --libs` mygame.o -o mygame -lSDL_image -lSDL_mixer

mygame.o:mygame.cpp includefile1.h includefile2.h
g++ -g -c `sdl-config --cflags` mygame.cpp

As for your problem separating out the pieces, do any of your modules depend on any of your other modules? Be sure to include them in the dependency list if they do, because if (for example) character.o depends on sprite.o, trying to make character.o will fail if sprite.o is not yet built. Beyond that, I don't do enough C++ to help you without more info about the program and the errors you're getting.

bigearsbilly · 09-29-2005, 02:48 AM

you can use makedepend to build the dependency list for you.
also did you know make has default actions for .c and .cpp files?
no need to expressly define them.

have a look at this - it's a make file I concocted for compiling and linking several C
files into a single target. Simple and effective.

It searches and creates a new dependency file each time. So you never have to touch
it even if you create new source files. Simply change *.c to *.cpp, add the link libraries and it would
work. (I think, maybe

)

Code:

TARGET=dummy_name
# ---------------------------------
# Standard makefile template
# just specify the target name above
# and the make file should sort it
# all out (hopefully)
# ---------------------------------

INCLUDEFILE = include.mk

# compiler  options
# ============
# CFLAGS = -g -Wall


# this should appear above the 'include' directive below
# calls for the target and then the cleanup
# =========================================
all: ${TARGET} cleanup 


-include ${INCLUDEFILE}

# ${INCLUDEFILE} should not exist when it's included.
# As it does not exist it is treated as a target.
# Therefore it is created anew each time,
# by the appropriate rule, below
# Which finds .c and .h files and calls makedepend for them
# =========================================================

${INCLUDEFILE}:
 @echo "### creating ${INCLUDEFILE}"
 @echo "### creating ${INCLUDEFILE}" > ${INCLUDEFILE}
 -@ echo  *.c|xargs echo SRCFILES = >> ${INCLUDEFILE}
 -@ echo  *.h|xargs echo HFILES = >> ${INCLUDEFILE}
 @  makedepend  -f${INCLUDEFILE} *.c


# (SRCFILES defined in INCLUDEFILE)
# =================================
OBJFILES = ${SRCFILES:.c=.o}


# this is the working target
# ==========================

${TARGET}: ${OBJFILES} 
 ${CC} -o $@ ${OBJFILES}

help: print_help cleanup

print_help:
 echo  OBJFILES = ${OBJFILES}
 echo  SRCFILES = ${SRCFILES}
 cat ${INCLUDEFILE}
 

clean:cleanup
 -@ rm -f  *.o 

# we need to delete the INCLUDEFILE otherwise
# new source and header files won't be picked up
# next time
# =========
cleanup:
 @echo "### deleting ${INCLUDEFILE}"
 -@ rm -f  ${INCLUDEFILE}

cyb0rg777 · 09-29-2005, 06:46 AM

All of my modules depend on one another.sprite.o depends on character.o for example.I guess what I'm missing is when to use .h and when to use modules.I will use CroMagnons option for now and save bigearsbillys example for later .Thanks to you both.