This has been solved
I am trying to use exp() from math.h in C, but it is failing to compile
whenever I pass a variable as the argument. The following code works just fine
#include <math.h>
#include <stdio.h>
int main() {
printf("exp(x) = %f\n", exp(12));
return 0;
}
While this code fails to compile
#include <math.h>
#include <stdio.h>
int main() {
double x = 12.0;
double result;
result = exp(x);
printf("exp(x) = %f\n", result);
return 0;
}
I am compiling with this
gcc -g -std=c99 -fsanitize=address -Wall -Wextra -o main dummy.c
and am getting the following compilation error (the warning is kept for completeness)
dummy.c: In function ‘main’:
dummy.c:6:9: warning: variable ‘result’ set but not used [-Wunused-but-set-variable]
double result;
^~~~~~
/usr/bin/ld: /tmp/ccyFoBpl.o: undefined reference to symbol 'exp@@GLIBC_2.2.5'
//lib/x86_64-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Edit:
I've tried adding the -lm flag as suggested in the comments, and I get a different error now.
/tmp/ccpBvvBq.o: In function `main':
/home/velcro/Documents/Undergrad/Math/DiffEq_292/lab2/dummy.c:8: undefined reference to `exp'
collect2: error: ld returned 1 exit status
Edit 2:
I needed to add the -lm to the end of compilation command. Now everything works. For anyone else interested see the linked question in the comments. My final compilation command is
gcc -g -std=c99 -fsanitize=address -Wall -Wextra -o main dummy.c -lm
