%ifndef ZSTRING_INC
%define ZSTRING_INC
%ifndef SYS_INC
%include "sys.inc"
%endif
%ifndef ALLOC_INC
%include "alloc.inc"
%endif

%macro make_zstring 2-*
%1:	db	%2
	%rep %0-2
	db %3
	%rotate 1
	%endrep
	db 0
%endm

	section .text
length_zstring:
	;; rax = zstring address
	push	rbp
	mov	rbp,	rsp
	;;
	mov	rdx,	rax
	xor	rax,	rax
.loop:	
	mov	cl,	byte [rdx]
	cmp	cl,	0
	je	.exit
	inc	rax
	inc	rdx
	jmp	.loop
.exit:
	;;
	mov	rsp,	rbp
	pop	rbp
	ret

print_zstring:
	;; rax = zstring address
	push	rbp
	mov	rbp,	rsp
	;;
	push	rax
	mov	rsi,	rax
	call	length_zstring
	mov	rdx,	rax
	mov	rax,	SYS_WRITE
	mov	rdi,	1
	syscall
	;; 
	mov	rsp,	rbp
	pop	rbp
	ret

%endif