LED blink for Nucleo STM32F103

blink.c

#include "stm32f10x.h"

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wmissing-declarations"
#pragma GCC diagnostic ignored "-Wreturn-type"

int
main(int argc, char* argv[])
{
  volatile int i = 0;
	volatile int flag = 0;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	GPIO_InitTypeDef pin_PA5;
	pin_PA5.GPIO_Pin = GPIO_Pin_5;
	pin_PA5.GPIO_Mode = GPIO_Mode_Out_PP;
	pin_PA5.GPIO_Speed = GPIO_Speed_50MHz;

	GPIO_Init(GPIOA, &pin_PA5);

  while (1){
    i = i+1;
    if(i < 1000000){
      continue;
    }
	  i = 0;
	  if(flag == 0){
		  GPIO_SetBits(GPIOA, GPIO_Pin_5);
		  flag = 1;
	  }else{
		  GPIO_ResetBits(GPIOA, GPIO_Pin_5);
		  flag = 0;
	  }
  }
}

#pragma GCC diagnostic pop