Function defined but not used in C

Question

I have following code:

static __inline__ LIST list_List(POINTER P)
{
  return list_Cons(P,list_Nil());
 }

After compilation I got following warning:

inlining is unlikely but function size may grow

I removed the inline and changed into the following :

static  LIST list_List(POINTER P)
{
  return list_Cons(P,list_Nil());
 }

Now I get the following warning:

list_List is defined but not used.

I didn't used to get above warning "function is defined but not used" before removing the inline. I got the warning only after I remove the inline. Actually the function is used .When i comment the above function, i am getting following error:

 list.o: In function `list_NReverse':
 list.c:(.text+0x148b): undefined reference to `list_List'
 list.o: In function `list_CopyWithElement':
 list.c:(.text+0x14ef): undefined reference to `list_List'
 list.c:(.text+0x150f): undefined reference to `list_List'
 list.o: In function `list_Copy':
 list.c:(.text+0x1549): undefined reference to `list_List'
 list.c:(.text+0x1569): undefined reference to `list_List'
 term.o:term.c:(.text+0x29e9): more undefined references to `list_List' follow
 collect2: ld returned 1 exit status
 make: *** [SPASS] Error 1

Can anybody please suggest me how can remove that warning.

Answer 1

"static" means that the function can only be used within the scope of the current compilation unit (source file, basically, unless you're doing weird things with #include).

Thus, the compiler is warning you that you have declared a function that cannot be used outside the current source file, but which is not (currently) used within that source file either.