simple arduino code without using avr headers in avr-libc - c

Question

I have this simple code
That I am trying to compile for arduino microcontroller and without using avr headers. I just defined all macros in my source program file
but my gcc-avr says
led.c:15:8: error: lvalue required as left operand of assignment
DDRB |= 0B100000; // PORTB5 1010
^
Now I can expect this error on some cpu that io area is not virtual memory space of this process but I am running my code on mocrocontroller that must have execution bit. how to get rid of this message and compile it and able to run on arduino
But the gcc-avr throws error that
#define F_CPU 16000000
#define BLINK_DELAY_MS 5000
#include <util/delay.h>
#define __SFR_OFFSET 0x20
#define _SFR_IO8(io_addr) ((io_addr) + __SFR_OFFSET)
#define DDRB _SFR_IO8(0x04)
#define PORTB _SFR_IO8(0x05)
int main (void)
{
// Arduino digital pin 13 (pin 5 of PORTB) for output
DDRB |= 0B100000; // PORTB5 1010
while(1) {
// turn LED on
PORTB |= 0B100000; // PORTB5
// _delay_ms(BLINK_DELAY_MS);
int x=0;
while(x<25)
{
x++;
}
x=0;
// turn LED off
PORTB &= ~ 0B100000; // PORTB5
//hello
while(x<25)
{
x++;
}
//_delay_ms(BLINK_DELAY_MS);
}
}

Answer 1

The problems are the macros, you are defining the register as an integer, not as an address to an integer.
DDRB expands to 0x04 + 0x20 so you end up with code like (0x04 + 0x20) |= 0B100000;. You should be able to fix this with a cast and then de-reference:
#define _SFR_IO8(io_addr) ( *(volatile uint8_t*) ((io_addr) + __SFR_OFFSET) )
For details see How to access a hardware register from firmware?
Please also note that macros starting with double underscore __ are reserved for the compiler, so we should never use that or we might end up with naming collisions.