AVR Freaks

I created a C project for the SAMD10 MCU and have an issue that i did not have before with the same code.

I have to add that i uninstalled my previous version of ATMEL studio and installed the latest version  ( 7.0.2397 ).

my problem is that i get a warning about implicit declaration when i use the delay function in the "asdf.c" file , but i don't get the warning when i use the delay function in the main.c file.

The "implicit declaration of function '_delay_ms' [-Wimplicit-function-declaration]"  warning takes me to the "asdf.c" file , not the delay function in the "main.c" file.

How do i properly use the delay function in other files thna the "main.c" file ?

Here are the contents 4 files...

main.c

#define F_CPU 8000000UL

#include "sam.h"
#include "delay.h"
#include "asdf.h"

int main(void)
{
    /* Initialize the SAM system */
    SystemInit();

    /* Replace with your application code */
    while (1)
    {
		_delay_ms(11);
    }
}

asdf.h

void asdf_func(int asdf_var);

asdf.c

void asdf_func(int asdf_var)
{
	asdf_var+1;
	_delay_ms(11);
}

delay.h

#ifndef DELAY_H_HEADER
#define DELAY_H_HEADER

#define RAMFUNC __attribute__ ((section(".ramfunc")))
#define OPTIMIZE_HIGH __attribute__((optimize("Os")))

#define cpu_ms_2_cy(ms, f_cpu)  (((uint64_t)(ms) * (f_cpu) + (uint64_t)(7e3-1ul)) / (uint64_t)7e3)
#define cpu_us_2_cy(us, f_cpu)  (((uint64_t)(us) * (f_cpu) + (uint64_t)(7e6-1ul)) / (uint64_t)7e6)
#define delay_cycles            portable_delay_cycles
#define cpu_delay_s(delay)      delay_cycles(cpu_ms_2_cy(1000 * delay, F_CPU))
#define cpu_delay_ms(delay)     delay_cycles(cpu_ms_2_cy(delay, F_CPU))
#define cpu_delay_us(delay)     delay_cycles(cpu_us_2_cy(delay, F_CPU))
#define _delay_us	cpu_delay_us
#define _delay_ms	cpu_delay_ms
#define _delay_s	cpu_delay_s

// Delay loop is put to SRAM so that FWS will not affect delay time
OPTIMIZE_HIGH
RAMFUNC
void portable_delay_cycles(uint32_t n)
{
	__asm (
	"loop: DMB	\n"
	#ifdef __ICCARM__
	"SUBS r0, r0, #1 \n"
	#else
	"SUB r0, r0, #1 \n"
	#endif
	"CMP r0, #0  \n"
	"BNE loop         "
	);
}