unresolved symbol pthread_create, first referenced in ./armrtk/src/task.obj - embedded

Question

I have been trying to figure this out for a few days now and cannot figure it out. I am using CCS as the IDE and I am working on windows. I am trying to create an RTOS Kernel on a MSP432 and need to use pthreads. I have been able to use pthreads in other examples but I am trying to do my own program and I get this issue when building :
unresolved symbol pthread_create, first referenced in ./armrtk/src/task.obj
I have included the file path into CCS and I cannot use a .cfg file because I am not using XDCTools. I just need help with this and I greatly appreciate it.
I also get a warning:
in pthread_create in TASK.C: #169-D argument of type "void *" is incompatible with parameter of type "void *(*)(void *)"
TASK.H
#ifndef TASK_H
#define TASK_H
#include <pthread.h>
struct task_t {
pthread_t* thread;
int threadCheck;
int state;
};
void *task1(void);
void *task2(void);
struct task_t *create_task(void* functionptr);
void delete_task(void *task);
#endif
TASK.C
#include <task.h>
#include <stdlib.h>
#include <pthread.h>
#define BLOCKED -1
#define READY 0
#define RUNNING 1
int testValue1 = 0;
int testValue2 = 0;
struct task_t *new_task;
pthread_t pntr;
struct task_t *create_task(void* functionptr) {
new_task = malloc(sizeof(struct task_t));
if(!new_task)
return NULL;
//set State of the new thread to ready
new_task->state = 0;
// check to see if pthread is created
**new_task->threadCheck = pthread_create(new_task->thread, NULL, functionptr, NULL);**
if(new_task->threadCheck!= 0){
//thread failed
return NULL;
}
return new_task;
}
void delete_task(void *task) {
if(task != NULL){
free(task);
pthread_exit(NULL);
}
}

Answer 1

The unresolved symbol error is a linker error, not a compiler error. You have failed to link the pthreads library.
With respect to the warning functionptr is a void* where pthread_create() expects a pointer-to-function with signature void fn(void*).
Your task functions have a different signature in any case: void fn(void), so in any event you will need to cast the function pointer in the call to pthread_create() (although you are loosing a useful means of passing information into a task function by omiting the void* argument).
Modify task.h:
typedef void* (*task_t)(void);
struct task_t *create_task( task_t functionptr);
The in task.cpp
new_task->threadCheck = pthread_create( new_task->thread,
NULL,
(void (*)(void *))functionptr,
NULL ) ;
The cast in the pthread_create() call alone would supress the warning, but it bad form to pass a function pointer as a generic void* since it would prevent the compiler warning you if you were to pass anything other then a function pointer of the expected form to to the create_task()`