Printing the argument vector on x86_64 MAC OS X (Assembly)

Print_argv.s

	// •••••••••••••••••••••
	// %bx, %bp and %r12 – %r14 (NEED TO BE PUSHED)
	// •••••••••••••••••••••
	// Argument parsing : %ri , %si , %dx , %cx , %r8 , %r9
	// •••••••••••••••••••••
.extern _puts
.text
.global print_argv
print_argv:
	// Save the return address from print_argv in %rax
	// and pop/push it throughout the procedure since the stack will be
	// continously popped throughout the procedure
	popq %rax

	POP_Stack:
		// The macho64 executable follows a format where the stack is populated
		// with several types of system information before the actual argument vector appears.
		// One can differentiate the argument vector (and the preceding argc value) from the other data by 
		// the NULL termination which appears on the stack before it
		popq %rsi
		
		// Once the null sign has been encounterd one can begin fetching the actual arguments
		cmpq $0, %rsi
		jne POP_Stack
		
		// Save the argc value which is actually available directly in %rdi from a call to _main
		// (decremented by 1 due to the popping of the executable name) in %r8
		popq %rdi
		subq $1, %rdi
		movq %rdi, %rcx		// Initialiase the counter
		popq %rdi		// POP the executable name
		

		POP_loop:
			popq %rdi	// POP the stack to aquire the next argument
			pushq %rax	// PUSH the print_argv return value
			pushq %rcx	// PUSH the iterator value
			call _puts
			
			popq %rcx	// POP the iterator value
			popq %rax	// POP the print_argv return value
			loop POP_loop

	pushq %rax		// PUSH the return value from print_argv back onto the stack
	xorq %rax, %rax		// Set the return value to zero
	ret
.end