Undefined reference error in a makefile while creating static library - c

Question

I have 4 .c files hello.c,here.c,bye.c and main.c.
One header file mylib.h
The contents are as follows
hello.c
#include<stdio.h>
void hello()
{
printf("Hello!\n");
}
here.c
#include<stdio.h>
void here()
{
printf("I am here \n");
}
bye.c
#include<stdio.h>
void bye()
{
printf("Bye,Bye");
}
main.c
#include<stdio.h>
#include "mylib.h"
int main()
{
hello();
here();
bye();
return 1;
}
mylib.h
#ifndef _mylib_
#define _mylib_
void hello();
void here();
void bye();
#endif
The makefile for creating a static lib is :
Makefile
all: myapp
#Macros
#Which Compiler
CC = gcc
#Where to install
INSTDIR = /usr/local/bin
#Where are include files kept
INCLUDE = .
#Options for developement
CFLAGS = -g -Wall -ansi
#Options for release
#CFLAGS = -O -Wall -ansi
#Local Libraries
MYLIB = mylib.a
myapp: main.o $(MYLIB)
$(CC) -o myapp main.o $(MYLIB)
$(MYLIB): hello.o here.o bye.o
ar rcs $# $^
main.o: main.c mylib.h
hello.o: hello.c
here.o: here.c
bye.o: bye.c
clean:
-rm main.o hello.o here.o bye.o $(MYLIB)
install: myapp
#if [ -d $(INSTDIR) ]; \
then \
cp myapp $(INSTDIR);\
chmod a+x $(INSTDIR)/myapp;\
chmod og-w $(INSTDIR)/myapp;\
echo "Installed in $(INSTDIR)";\
else \
echo "Sorry, $(INSTDIR) does not exist";\
fi
Problem: When I execute the command
make -f Makefile all
I get the error:
gcc -o myapp main.o mylib.a
main.o: In function `main':
/home/usr/molly/main.c:7: undefined reference to `hello()'
/home/usr/molly/main.c:8: undefined reference to `here()'
/home/usr/molly/main.c:9: undefined reference to `bye()'
main.o:(.eh_frame+0x12): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status
make: *** [myapp] Error 1
Questions : How do I resolve this? Why is there an undefined reference

Answer 1

This actually works for me. Try rm mylib.a and then make

Answer 2

This works for me with the caveot that you are not specifying an 'all' target:
xxxx#xxxx-desktop:~/Desktop$ make -f Makefile
cc -g -Wall -ansi -c -o main.o main.c
cc -g -Wall -ansi -c -o hello.o hello.c
cc -g -Wall -ansi -c -o here.o here.c
cc -g -Wall -ansi -c -o bye.o bye.c
ar rcs mylib.a hello.o here.o bye.o
cc -o myapp main.o mylib.a
xxxx#xxxx-desktop:~/Desktop$ ./myapp
Hello!
I am here
Bye,Byexxxx#xxxx-desktop:~/Desktop$