func()

in assembler.go [174:203]

• 23 lines of code
• 5 McCabe index (conditional complexity)

func (p *Program) resolveLabel(jump JumpIf, label Label) (uint8, error) {
	dest := p.labels[label]
	skipN := p.computeSkipN(jump, label)

	for skipN < 0 {
		dest = dest[1:]
		if len(dest) == 0 {
			return 0, fmt.Errorf("backward jumps are not supported")
		}
		p.labels[label] = dest
		skipN = p.computeSkipN(jump, label)
	}

	// BPF does not support long conditional jumps.
	if skipN > math.MaxUint8 {
		insertAfter := findInsertAfter(p.jumps, jump)

		// If the jump destination is a return instruction, copy it and add an early return,
		// if not, insert a long jump.
		jumpDest := p.instructions[dest[0]]
		if _, ok := jumpDest.(bpf.RetConstant); !ok {
			jumpDest = bpf.Jump{Skip: uint32(skipN - int(insertAfter.index))}
		}

		insertIndex := p.insertAfter(insertAfter.index, jumpDest)
		p.labels[label] = append([]Index{insertIndex}, dest...)
		skipN = p.computeSkipN(jump, label)
	}
	return uint8(skipN), nil
}