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") {

		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)
			}

		// Base case: initial conversion from unsafe.Pointer to uintptr.
		return len(x.Args) == 1 &&
			hasBasicType(info, x.Fun, types.Uintptr) &&
			hasBasicType(info, x.Args[0], types.UnsafePointer)

	case *ast.BinaryExpr:
		// "It is valid both to add and to subtract offsets from a
		// pointer in this way. It is also valid to use &^ to round
		// pointers, usually for alignment."
		switch x.Op {

		}
		buf.WriteByte(')')

	case *ast.StarExpr:
		buf.WriteByte('*')
		WriteExpr(buf, x.X)

	case *ast.UnaryExpr:
		buf.WriteString(x.Op.String())
		WriteExpr(buf, x.X)

	case *ast.BinaryExpr:
		WriteExpr(buf, x.X)
		buf.WriteByte(' ')
		buf.WriteString(x.Op.String())
		buf.WriteByte(' ')
		WriteExpr(buf, x.Y)

	case *ast.ArrayType:
		buf.WriteByte('[')
		if x.Len != nil {

	case *ast.BadDecl:
		return 1 << nBadDecl
	case *ast.BadExpr:
		return 1 << nBadExpr
	case *ast.BadStmt:
		return 1 << nBadStmt
	case *ast.BasicLit:
		return 1 << nBasicLit
	case *ast.BinaryExpr:
		return 1 << nBinaryExpr
	case *ast.BlockStmt:
		return 1 << nBlockStmt
	case *ast.BranchStmt:
		return 1 << nBranchStmt
	case *ast.CallExpr:
		return 1 << nCallExpr
	case *ast.CaseClause:

			Walk(v, n.Type)
		}

	case *CallExpr:
		Walk(v, n.Fun)
		walkList(v, n.Args)

	case *StarExpr:
		Walk(v, n.X)

	case *UnaryExpr:
		Walk(v, n.X)

	case *BinaryExpr:
		Walk(v, n.X)
		Walk(v, n.Y)

	case *KeyValueExpr:
		Walk(v, n.Key)
		Walk(v, n.Value)

	// Types
	case *ArrayType:
		if n.Len != nil {
			Walk(v, n.Len)
		}
		Walk(v, n.Elt)

// extracting both the binary exprs (blist) and leaf types (tlist).
func flattenUnion(list []ast.Expr, x ast.Expr) (blist, tlist []ast.Expr) {
	if o, _ := x.(*ast.BinaryExpr); o != nil && o.Op == token.OR {
		blist, tlist = flattenUnion(list, o.X)
		blist = append(blist, o)
		x = o.Y
	}
	return blist, append(tlist, x)