# ADR-0008 - Use NullAway for null checking

## Date

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading

	BEQ	1(PC)
	BEQ	2(PC)
	TBZ	$1, R1, 2(PC)
	TBNZ	$2, R2, 2(PC)
	JMP	foo(SB)
	CALL	foo(SB)

// ADR
	ADR	next, R11     // ADR R11 // 2b000010
next:
	NOP
	ADR -2(PC), R10    // 0a000010
	ADR 2(PC), R16     // 10000010
	ADR -26(PC), R1    // 01000010
	ADR 12(PC), R2     // 02000010
	ADRP -2(PC), R10   // 0a000090
	ADRP 2(PC), R16    // 10000090
	ADRP -26(PC), R1   // 01000090

* Use American English spelling in code, comments, and documentation (e.g., "color" not "colour", "initialize" not "initialise"). See [ADR-0009](architecture/standards/0009-use-american-english.md) for details.

		}
		p.errorf("wrong number of arguments to %s instruction", op)
		return
	case 1:
		target = &a[0]
	case 2:
		// Special 2-operand jumps.
		if p.arch.Family == sys.ARM64 && arch.IsARM64ADR(op) {
			// ADR label, R. Label is in From.
			target = &a[0]
			prog.To = a[1]
			targetAddr = &prog.From
		} else {
			target = &a[1]
			prog.From = a[0]
		}
	case 3:
		if p.arch.Family == sys.PPC64 {