Makefile Help

ETC Homework & Coursework Questions
1

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!

  1. The problem statement, all variables and given/known data:
    I have been trying to make the program swap but i have been getting errors with the makefile such as
driver.o: In function `main':
driver.c:(.text+0x34): undefined reference to `swap'
driver.c:(.text+0x48): undefined reference to `swap'
driver.c:(.text+0x5c): undefined reference to `swap'
collect2: ld returned 1 exit status
make: *** [swapbig] Error 1

i dont know why the driver has a swap when i declare the function as a swap_big function. and the makefile error is a spacing error but i used my previous makefiles for reference and it is ok, i dont know what i did wrong.
2. Relevant commands, code, scripts, algorithms:
swapbig.c

#include "swapbig.h"

void swap_big(float *a, float *b)
{

   float temp;

        if ( temp <= *a )
        {temp = *a;
         *a = *b;
        *b = temp;
        }
printf(" %x, contents %f\n", a, *a);
printf(" %x, contents %f\n", b, *b);
}

swapbig.h
#include <stdio.h>

/* Given two pointer values (floats) and swap the values in cell pointed
 * return the swap value, the first has to be less than or equal to the second*/

void swap_big(float *a, float *b);

driver.c

#include "swapbig.h"
//#define DEBUG

int main()
{

        #ifdef DEBUG
        printf("Initial values:\t a = %f, b = %f, c = %f\n",a, b, c);
        #endif

        swap_big(&a, &b);

        #ifdef DEBUG
        printf("First swap:\t a = %f, b = %f, c = %f\n",a, b, c);
        #endif

        swap_big(&b, &c);

        #ifdef DEBUG
        printf("Second swap:\t a = %f, b = %f, c = %f\n",a, b, c);
        #endif

        swap_big(&a, &b);

        #ifdef DEBUG
        printf("Third swap:\t a = %f, b = %f, c = %f\n",a, b, c);
        #endif

}
  1. The attempts at a solution (include all code and scripts):
    makefile
# target to make all programs for Lab 12
 all: swap swapbig reorder

# Problem 1 - swap programs
#complete the dependency and action lines for your filenames
swap: swaptest.o swap.o
        cc swaptest.o swap.o -o swap

swaptest.o: swap.h

swap.o: swap.h

# Problem 2 - swapbig programs
swapbig:swapbig.o
        cc driver.o swapbig.o -o swapbig

driver.o: swapbig.h

swapbig.o: swapbig.h

# Problem 3 - reorder programs
reorder: reorder.o
        cc driver1.o  reorder.o -o reorder

driver1.o: reorder.h

reorder.o: reorder.h

# source file dependencies
# add target lines showing dependencies for your .o files


# utility targets

clean:
        rm -f *.o

real_clean: clean
        rm -f swap swapbig reorder
  1. Complete Name of School (University), City (State), Country, Name of Professor, and Course Number (Link to Course):
    University of Hawaii at Manoa, Honolulu(HI), Oahu(Hawaii), Tep Dobry, ee160 EE 160: Lab 12

Note: Without school/professor/course information, you will be banned if you post here! You must complete the entire template (not just parts of it).

2

That's weird that it'd be complaining about no 'swap', driver.c definitely doesn't use it from what I can tell. Maybe that's leftover junk from a previous build, try cleaning out your .o files. See if there's any leftover after you run 'make clean', maybe your makefile isn't deleting them all.

1 Like