func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)

	nodeFilter := []ast.Node{
		(*ast.BinaryExpr)(nil),
	}
	seen := make(map[*ast.BinaryExpr]bool)
	inspect.Preorder(nodeFilter, func(n ast.Node) {
		e := n.(*ast.BinaryExpr)
		if seen[e] {
			// Already processed as a subexpression of an earlier node.
			return
		}

		var op boolOp
		switch e.Op {

}

func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)

	nodeFilter := []ast.Node{
		(*ast.BinaryExpr)(nil),
	}
	inspect.Preorder(nodeFilter, func(n ast.Node) {
		e := n.(*ast.BinaryExpr)

		// Only want == or != comparisons.
		if e.Op != token.EQL && e.Op != token.NEQ {
			return
		}

		// Only want comparisons with a nil identifier on one side.

// between expressions of interface and non-interface type, and
// returns an expression that yields the *runtime._type value
// representing the non-interface type.
func CompareRType(pos src.XPos, n *ir.BinaryExpr) ir.Node {
	assertOp2(n, ir.OEQ, ir.ONE)
	base.AssertfAt(n.X.Type().IsInterface() != n.Y.Type().IsInterface(), n.Pos(), "expect mixed interface and non-interface, have %L and %L", n.X, n.Y)
	if hasRType(n, n.RType, "RType") {

        // Given: `x = expression`
        // Expected type of `expression` is type of `x`
        val assignmentExpression =
            expression.unwrapQualified<KtBinaryExpression> { binaryExpr, expr -> binaryExpr.right == expr && binaryExpr.operationToken == KtTokens.EQ }
                ?: return null
        val variableExpression = assignmentExpression.left as? KtNameReferenceExpression ?: return null

		ir.OUNSAFEADD:
		n := n.(*ir.BinaryExpr)
		n.X = walkExpr(n.X, init)
		n.Y = walkExpr(n.Y, init)
		return n

	case ir.OUNSAFESLICE:
		n := n.(*ir.BinaryExpr)
		return walkUnsafeSlice(n, init)

	case ir.OUNSAFESTRING:
		n := n.(*ir.BinaryExpr)
		return walkUnsafeString(n, init)

	case ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:

		return &ast.ReturnStmt{
			Results: []ast.Expr{&ast.BinaryExpr{
				Op: token.ADD,
				X:  &ast.Ident{Name: "DW_ABRV_PUTVAR_START"},
				Y:  &ast.BasicLit{Kind: token.INT, Value: strconv.Itoa(abbrevs[abbrev])}}}}
	}
	if pvacfg.attr != "" {
		return pvacfgvisitnode(pvacfg.then, tag, append(path, pvacfg), abbrevs)
	} else if pvacfg.cond != nil {

		updateDead(pass.TypesInfo, dead, n)
	})

	nodeFilter = []ast.Node{
		(*ast.AssignStmt)(nil),
		(*ast.BinaryExpr)(nil),
	}
	inspect.Preorder(nodeFilter, func(node ast.Node) {
		if dead[node] {
			// Skip shift checks on unreachable nodes.
			return
		}

		switch node := node.(type) {
		case *ast.BinaryExpr:
			if node.Op == token.SHL || node.Op == token.SHR {
				checkLongShift(pass, node, node.X, node.Y)
			}

	n.SetOp(ir.ORECOVERFP)
	n.SetType(types.Types[types.TINTER])
	n.Args = []ir.Node{Expr(fp)}
	return n
}

// tcUnsafeAdd typechecks an OUNSAFEADD node.
func tcUnsafeAdd(n *ir.BinaryExpr) *ir.BinaryExpr {
	n.X = AssignConv(Expr(n.X), types.Types[types.TUNSAFEPTR], "argument to unsafe.Add")
	n.Y = DefaultLit(Expr(n.Y), types.Types[types.TINT])
	if n.X.Type() == nil || n.Y.Type() == nil {
		n.SetType(nil)

//	    <----B----->
//
// the ast.BinaryExpr(+) node is considered to enclose interval B
// even though its [Pos()..End()) is actually only interval A.
// This behaviour makes user interfaces more tolerant of imperfect
// input.
//
// This function treats tokens as nodes, though they are not included
// in the result. e.g. PathEnclosingInterval("+") returns the
// enclosing ast.BinaryExpr("x + y").
//

	// a valid arithmetic expression
	src := "a + b"
	x, err := ParseExpr(src)
	if err != nil {
		t.Errorf("ParseExpr(%q): %v", src, err)
	}
	// sanity check
	if _, ok := x.(*ast.BinaryExpr); !ok {
		t.Errorf("ParseExpr(%q): got %T, want *ast.BinaryExpr", src, x)
	}

	// a valid type expression
	src = "struct{x *int}"
	x, err = ParseExpr(src)
	if err != nil {
		t.Errorf("ParseExpr(%q): %v", src, err)
	}