Question

I am beginner when it comes to writing makefiles but I am having this linking issue with my program. Basically I am getting the above error when I try to build it on a remote machine.
Here is my makefile:

SRCS = gt_cfs.c gt_kthread.c gt_matrix.c gt_pq.c gt_signal.c gt_spinlock.c \
    gt_uthread.c red_black_tree.c stack.c misc.c

HDRS = gt_bitops.h gt_cfs.h gt_include.h gt_kthread.h gt_pq.h gt_signal.h \
    gt_tailq.h gt_uthread.h red_black_tree.h stack.h misc.h

OBJS = gt_cfs.o gt_kthread.o gt_matrix.o gt_pq.o gt_signal.o gt_spinlock.o \
    gt_uthread.o red_black_tree.o stack.o misc.o

CC = gcc

CFLAGS = -Wall -pedantic -lrt -lm

PROGRAM = cfs_gtthreads

.PHONY: clean

all: $(PROGRAM)

$(PROGRAM):     $(OBJS)
    $(CC) $(CFLAGS) $(OBJS) -o $(PROGRAM)

gt_include.h:   gt_bitops.h gt_cfs.h gt_kthread.h gt_pq.h \
            gt_signal.h gt_tailq.h gt_uthread.h

gt_cfs.o:   gt_cfs.c 

gt_kthread.o:   gt_kthread.c 

gt_matrix.o:    gt_matrix.c 

gt_pq.o:    gt_pq.c

gt_signal.o:    gt_signal.c

gt_spinlock.o:  gt_spinlock.c 

gt_uthread.o:   gt_uthread.c 

red_black_tree.o:   red_black_tree.c

stack.o:        stack.c

clean:          
rm -f *.o *~ $(PROGRAM)

Now this code WORKS on my laptop but I have to run my program on a remote machine through SSH. Anyway on that machine is where I get this error, so I am confused as to why it can’t link the two libraries: math and time (-lm and -lrt). The gcc versions are different, mine is 4.5.2 and the cluster machine is 4.1.2. I am also running mine on Ubuntu and the cluster machine is Red-Hat. I don’t know what differences would cause this error since those are standard libraries. Any help is appreciated.

Thanks in advance.

Answer 1

Try using a LDFLAGS variable with -lrt -lm and put $(LDFLAGS) after the $(OBJS).