Thread: undefined reference to

I keep getting compile error:

../../thread/thread.c:318: undefined reference to `pid_alloc`
../../thread/thread.c:350: undefined reference to `pi_get`

thread.c looks like:

Code:

....
#include <pid.h>
....
line 318:   assert(pid_alloc(tid));
...
line 350:   struct pidinfo *wait_t = pi_get(tid)
...

pid.h:

Code:

struct pidinfo *pi_get(pid_t pid);
...
int pid_alloc(pid_t *retval)
...

pid.c:

Code:

...
struct pidinfo *
pi_get(pid_t pid)
{
...
}
...
int
pid_alloc(pid_t *reval)
{
...
}
...

I can't understand why I'm getting this error when pid.h and pid.c seem to be fine

found it

this line is wrong

Code:

#include <pid.h>

but w/o <pid.h> none of the functions defined in it will work.

Originally Posted by yxunomei

when you refer to an external library of your own, you have to use .... (fill in the blanks)

i think u can change this sentence to like "when u refer to an external library of your own which is located in the current directory, you have to use ..."

because even thought if u have your own .h file and when u place it in include directory u will refer that header file using <>

ssharish2005

ah yes, i forgot to include that possibility

Code:

#include <thatPossibility.h>

whoa now dat's a new knowledge for me...

thank's sir!

Thanks for the feedback guys.

From what I understand you have to use different syntax when referencing headers files that are not in the "include" directory.

However, I have pid.h along with all my other header files that are "included" in thread.c inside the include folder... therefore all includes are of the form "#include <filename.h>"

Could there be a problem within my pid.c that causes this?

try this

Code:

#include "pid.h"

notice the double quotes

if that doesn't work, try dwk's suggestion