update revive lint to latest commit (#12921)

* update revive lint to latest commit

* make fmt

* change import

vendor/github.com/mgechev/revive/formatter/friendly.go

@@ -10,11 +10,6 @@ import (
 	"github.com/olekukonko/tablewriter"
 )
 
-var (
-	errorEmoji   = color.RedString("✘")
-	warningEmoji = color.YellowString("⚠")
-)
-
 var newLines = map[rune]bool{
 	0x000A: true,
 	0x000B: true,
@@ -25,6 +20,14 @@ var newLines = map[rune]bool{
 	0x2029: true,
 }
 
+func getErrorEmoji() string {
+	return color.RedString("✘")
+}
+
+func getWarningEmoji() string {
+	return color.YellowString("⚠")
+}
+
 // Friendly is an implementation of the Formatter interface
 // which formats the errors to JSON.
 type Friendly struct {
@@ -68,9 +71,9 @@ func (f *Friendly) printFriendlyFailure(failure lint.Failure, severity lint.Seve
 }
 
 func (f *Friendly) printHeaderRow(failure lint.Failure, severity lint.Severity) {
-	emoji := warningEmoji
+	emoji := getWarningEmoji()
 	if severity == lint.SeverityError {
-		emoji = errorEmoji
+		emoji = getErrorEmoji()
 	}
 	fmt.Print(f.table([][]string{{emoji, "https://revive.run/r#" + failure.RuleName, color.GreenString(failure.Failure)}}))
 }
@@ -85,9 +88,9 @@ type statEntry struct {
 }
 
 func (f *Friendly) printSummary(errors, warnings int) {
-	emoji := warningEmoji
+	emoji := getWarningEmoji()
 	if errors > 0 {
-		emoji = errorEmoji
+		emoji = getErrorEmoji()
 	}
 	problemsLabel := "problems"
 	if errors+warnings == 1 {

vendor/github.com/mgechev/revive/rule/cognitive-complexity.go

@@ -52,7 +52,7 @@ type cognitiveComplexityLinter struct {
 func (w cognitiveComplexityLinter) lint() {
 	f := w.file
 	for _, decl := range f.AST.Decls {
-		if fn, ok := decl.(*ast.FuncDecl); ok {
+		if fn, ok := decl.(*ast.FuncDecl); ok && fn.Body != nil {
 			v := cognitiveComplexityVisitor{}
 			c := v.subTreeComplexity(fn.Body)
 			if c > w.maxComplexity {
@@ -109,7 +109,7 @@ func (v *cognitiveComplexityVisitor) Visit(n ast.Node) ast.Visitor {
 		return nil // skip visiting binexp sub-tree (already visited by binExpComplexity)
 	case *ast.BranchStmt:
 		if n.Label != nil {
-			v.complexity += 1
+			v.complexity++
 		}
 	}
 	// TODO handle (at least) direct recursion

vendor/github.com/mgechev/revive/rule/defer.go

@@ -0,0 +1,137 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// DeferRule lints unused params in functions.
+type DeferRule struct{}
+
+// Apply applies the rule to given file.
+func (r *DeferRule) Apply(file *lint.File, arguments lint.Arguments) []lint.Failure {
+	allow := r.allowFromArgs(arguments)
+
+	var failures []lint.Failure
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintDeferRule{onFailure: onFailure, allow: allow}
+
+	ast.Walk(w, file.AST)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (r *DeferRule) Name() string {
+	return "defer"
+}
+
+func (r *DeferRule) allowFromArgs(args lint.Arguments) map[string]bool {
+	if len(args) < 1 {
+		allow := map[string]bool{
+			"loop":        true,
+			"call-chain":  true,
+			"method-call": true,
+			"return":      true,
+			"recover":     true,
+		}
+
+		return allow
+	}
+
+	aa, ok := args[0].([]interface{})
+	if !ok {
+		panic(fmt.Sprintf("Invalid argument '%v' for 'defer' rule. Expecting []string, got %T", args[0], args[0]))
+	}
+
+	allow := make(map[string]bool, len(aa))
+	for _, subcase := range aa {
+		sc, ok := subcase.(string)
+		if !ok {
+			panic(fmt.Sprintf("Invalid argument '%v' for 'defer' rule. Expecting string, got %T", subcase, subcase))
+		}
+		allow[sc] = true
+	}
+
+	return allow
+}
+
+type lintDeferRule struct {
+	onFailure  func(lint.Failure)
+	inALoop    bool
+	inADefer   bool
+	inAFuncLit bool
+	allow      map[string]bool
+}
+
+func (w lintDeferRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.ForStmt:
+		w.visitSubtree(n.Body, w.inADefer, true, w.inAFuncLit)
+		return nil
+	case *ast.RangeStmt:
+		w.visitSubtree(n.Body, w.inADefer, true, w.inAFuncLit)
+		return nil
+	case *ast.FuncLit:
+		w.visitSubtree(n.Body, w.inADefer, false, true)
+		return nil
+	case *ast.ReturnStmt:
+		if len(n.Results) != 0 && w.inADefer && w.inAFuncLit {
+			w.newFailure("return in a defer function has no effect", n, 1.0, "logic", "return")
+		}
+	case *ast.CallExpr:
+		if isIdent(n.Fun, "recover") && !w.inADefer {
+			// confidence is not 1 because recover can be in a function that is deferred elsewhere
+			w.newFailure("recover must be called inside a deferred function", n, 0.8, "logic", "recover")
+		}
+	case *ast.DeferStmt:
+		w.visitSubtree(n.Call.Fun, true, false, false)
+
+		if w.inALoop {
+			w.newFailure("prefer not to defer inside loops", n, 1.0, "bad practice", "loop")
+		}
+
+		switch fn := n.Call.Fun.(type) {
+		case *ast.CallExpr:
+			w.newFailure("prefer not to defer chains of function calls", fn, 1.0, "bad practice", "call-chain")
+		case *ast.SelectorExpr:
+			if id, ok := fn.X.(*ast.Ident); ok {
+				isMethodCall := id != nil && id.Obj != nil && id.Obj.Kind == ast.Typ
+				if isMethodCall {
+					w.newFailure("be careful when deferring calls to methods without pointer receiver", fn, 0.8, "bad practice", "method-call")
+				}
+			}
+		}
+		return nil
+	}
+
+	return w
+}
+
+func (w lintDeferRule) visitSubtree(n ast.Node, inADefer, inALoop, inAFuncLit bool) {
+	nw := &lintDeferRule{
+		onFailure:  w.onFailure,
+		inADefer:   inADefer,
+		inALoop:    inALoop,
+		inAFuncLit: inAFuncLit,
+		allow:      w.allow}
+	ast.Walk(nw, n)
+}
+
+func (w lintDeferRule) newFailure(msg string, node ast.Node, confidence float64, cat string, subcase string) {
+	if !w.allow[subcase] {
+		return
+	}
+
+	w.onFailure(lint.Failure{
+		Confidence: confidence,
+		Node:       node,
+		Category:   cat,
+		Failure:    msg,
+	})
+}

vendor/github.com/mgechev/revive/rule/early-return.go

@@ -0,0 +1,78 @@
+package rule
+
+import (
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// EarlyReturnRule lints given else constructs.
+type EarlyReturnRule struct{}
+
+// Apply applies the rule to given file.
+func (r *EarlyReturnRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintEarlyReturnRule{onFailure: onFailure}
+	ast.Walk(w, file.AST)
+	return failures
+}
+
+// Name returns the rule name.
+func (r *EarlyReturnRule) Name() string {
+	return "early-return"
+}
+
+type lintEarlyReturnRule struct {
+	onFailure func(lint.Failure)
+}
+
+func (w lintEarlyReturnRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.IfStmt:
+		if n.Else == nil {
+			// no else branch
+			return w
+		}
+
+		elseBlock, ok := n.Else.(*ast.BlockStmt)
+		if !ok {
+			// is if-else-if
+			return w
+		}
+
+		lenElseBlock := len(elseBlock.List)
+		if lenElseBlock < 1 {
+			// empty else block, continue (there is another rule that warns on empty blocks)
+			return w
+		}
+
+		lenThenBlock := len(n.Body.List)
+		if lenThenBlock < 1 {
+			// then block is empty thus the stmt can be simplified
+			w.onFailure(lint.Failure{
+				Confidence: 1,
+				Node:       n,
+				Failure:    "if c { } else {... return} can be simplified to if !c { ... return }",
+			})
+
+			return w
+		}
+
+		_, lastThenStmtIsReturn := n.Body.List[lenThenBlock-1].(*ast.ReturnStmt)
+		_, lastElseStmtIsReturn := elseBlock.List[lenElseBlock-1].(*ast.ReturnStmt)
+		if lastElseStmtIsReturn && !lastThenStmtIsReturn {
+			w.onFailure(lint.Failure{
+				Confidence: 1,
+				Node:       n,
+				Failure:    "if c {...} else {... return } can be simplified to if !c { ... return } ...",
+			})
+		}
+	}
+
+	return w
+}

vendor/github.com/mgechev/revive/rule/empty-block.go

@@ -17,7 +17,7 @@ func (r *EmptyBlockRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure
 		failures = append(failures, failure)
 	}
 
-	w := lintEmptyBlock{make([]*ast.BlockStmt, 0), onFailure}
+	w := lintEmptyBlock{make(map[*ast.BlockStmt]bool, 0), onFailure}
 	ast.Walk(w, file.AST)
 	return failures
 }
@@ -28,49 +28,38 @@ func (r *EmptyBlockRule) Name() string {
 }
 
 type lintEmptyBlock struct {
-	ignore    []*ast.BlockStmt
+	ignore    map[*ast.BlockStmt]bool
 	onFailure func(lint.Failure)
 }
 
 func (w lintEmptyBlock) Visit(node ast.Node) ast.Visitor {
-	fd, ok := node.(*ast.FuncDecl)
-	if ok {
-		w.ignore = append(w.ignore, fd.Body)
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		w.ignore[n.Body] = true
 		return w
-	}
-
-	fl, ok := node.(*ast.FuncLit)
-	if ok {
-		w.ignore = append(w.ignore, fl.Body)
+	case *ast.FuncLit:
+		w.ignore[n.Body] = true
 		return w
-	}
-
-	block, ok := node.(*ast.BlockStmt)
-	if !ok {
-		return w
-	}
-
-	if mustIgnore(block, w.ignore) {
-		return w
-	}
-
-	if len(block.List) == 0 {
-		w.onFailure(lint.Failure{
-			Confidence: 1,
-			Node:       block,
-			Category:   "logic",
-			Failure:    "this block is empty, you can remove it",
-		})
+	case *ast.RangeStmt:
+		if len(n.Body.List) == 0 {
+			w.onFailure(lint.Failure{
+				Confidence: 0.9,
+				Node:       n,
+				Category:   "logic",
+				Failure:    "this block is empty, you can remove it",
+			})
+			return nil // skip visiting the range subtree (it will produce a duplicated failure)
+		}
+	case *ast.BlockStmt:
+		if !w.ignore[n] && len(n.List) == 0 {
+			w.onFailure(lint.Failure{
+				Confidence: 1,
+				Node:       n,
+				Category:   "logic",
+				Failure:    "this block is empty, you can remove it",
+			})
+		}
 	}
 
 	return w
 }
-
-func mustIgnore(block *ast.BlockStmt, blackList []*ast.BlockStmt) bool {
-	for _, b := range blackList {
-		if b == block {
-			return true
-		}
-	}
-	return false
-}

vendor/github.com/mgechev/revive/rule/identical-branches.go

@@ -0,0 +1,82 @@
+package rule
+
+import (
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// IdenticalBranchesRule warns on constant logical expressions.
+type IdenticalBranchesRule struct{}
+
+// Apply applies the rule to given file.
+func (r *IdenticalBranchesRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	astFile := file.AST
+	w := &lintIdenticalBranches{astFile, onFailure}
+	ast.Walk(w, astFile)
+	return failures
+}
+
+// Name returns the rule name.
+func (r *IdenticalBranchesRule) Name() string {
+	return "identical-branches"
+}
+
+type lintIdenticalBranches struct {
+	file      *ast.File
+	onFailure func(lint.Failure)
+}
+
+func (w *lintIdenticalBranches) Visit(node ast.Node) ast.Visitor {
+	n, ok := node.(*ast.IfStmt)
+	if !ok {
+		return w
+	}
+
+	if n.Else == nil {
+		return w
+	}
+	branches := []*ast.BlockStmt{n.Body}
+
+	elseBranch, ok := n.Else.(*ast.BlockStmt)
+	if !ok { // if-else-if construction
+		return w
+	}
+	branches = append(branches, elseBranch)
+
+	if w.identicalBranches(branches) {
+		w.newFailure(n, "both branches of the if are identical")
+	}
+
+	return w
+}
+
+func (w *lintIdenticalBranches) identicalBranches(branches []*ast.BlockStmt) bool {
+	if len(branches) < 2 {
+		return false
+	}
+
+	ref := gofmt(branches[0])
+	for i := 1; i < len(branches); i++ {
+		if gofmt(branches[i]) != ref {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (w lintIdenticalBranches) newFailure(node ast.Node, msg string) {
+	w.onFailure(lint.Failure{
+		Confidence: 1,
+		Node:       node,
+		Category:   "logic",
+		Failure:    msg,
+	})
+}

vendor/github.com/mgechev/revive/rule/unconditional-recursion.go

@@ -0,0 +1,183 @@
+package rule
+
+import (
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// UnconditionalRecursionRule lints given else constructs.
+type UnconditionalRecursionRule struct{}
+
+// Apply applies the rule to given file.
+func (r *UnconditionalRecursionRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintUnconditionalRecursionRule{onFailure: onFailure}
+	ast.Walk(w, file.AST)
+	return failures
+}
+
+// Name returns the rule name.
+func (r *UnconditionalRecursionRule) Name() string {
+	return "unconditional-recursion"
+}
+
+type funcDesc struct {
+	reciverID *ast.Ident
+	id        *ast.Ident
+}
+
+func (fd *funcDesc) equal(other *funcDesc) bool {
+	receiversAreEqual := (fd.reciverID == nil && other.reciverID == nil) || fd.reciverID != nil && other.reciverID != nil && fd.reciverID.Name == other.reciverID.Name
+	idsAreEqual := (fd.id == nil && other.id == nil) || fd.id.Name == other.id.Name
+
+	return receiversAreEqual && idsAreEqual
+}
+
+type funcStatus struct {
+	funcDesc            *funcDesc
+	seenConditionalExit bool
+}
+
+type lintUnconditionalRecursionRule struct {
+	onFailure   func(lint.Failure)
+	currentFunc *funcStatus
+}
+
+// Visit will traverse the file AST.
+// The rule is based in the following algorithm: inside each function body we search for calls to the function itself.
+// We do not search inside conditional control structures (if, for, switch, ...) because any recursive call inside them is conditioned
+// We do search inside conditional control structures are statements that will take the control out of the function (return, exit, panic)
+// If we find conditional control exits, it means the function is NOT unconditionally-recursive
+// If we find a recursive call before finding any conditional exit, a failure is generated
+// In resume: if we found a recursive call control-dependant from the entry point of the function then we raise a failure.
+func (w lintUnconditionalRecursionRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		var rec *ast.Ident
+		switch {
+		case n.Recv == nil || n.Recv.NumFields() < 1 || len(n.Recv.List[0].Names) < 1:
+			rec = nil
+		default:
+			rec = n.Recv.List[0].Names[0]
+		}
+
+		w.currentFunc = &funcStatus{&funcDesc{rec, n.Name}, false}
+	case *ast.CallExpr:
+		var funcID *ast.Ident
+		var selector *ast.Ident
+		switch c := n.Fun.(type) {
+		case *ast.Ident:
+			selector = nil
+			funcID = c
+		case *ast.SelectorExpr:
+			var ok bool
+			selector, ok = c.X.(*ast.Ident)
+			if !ok { // a.b....Foo()
+				return nil
+			}
+			funcID = c.Sel
+		default:
+			return w
+		}
+
+		if w.currentFunc != nil && // not in a func body
+			!w.currentFunc.seenConditionalExit && // there is a conditional exit in the function
+			w.currentFunc.funcDesc.equal(&funcDesc{selector, funcID}) {
+			w.onFailure(lint.Failure{
+				Category:   "logic",
+				Confidence: 1,
+				Node:       n,
+				Failure:    "unconditional recursive call",
+			})
+		}
+	case *ast.IfStmt:
+		w.updateFuncStatus(n.Body)
+		w.updateFuncStatus(n.Else)
+		return nil
+	case *ast.SelectStmt:
+		w.updateFuncStatus(n.Body)
+		return nil
+	case *ast.RangeStmt:
+		w.updateFuncStatus(n.Body)
+		return nil
+	case *ast.TypeSwitchStmt:
+		w.updateFuncStatus(n.Body)
+		return nil
+	case *ast.SwitchStmt:
+		w.updateFuncStatus(n.Body)
+		return nil
+	case *ast.GoStmt:
+		for _, a := range n.Call.Args {
+			ast.Walk(w, a) // check if arguments have a recursive call
+		}
+		return nil // recursive async call is not an issue
+	case *ast.ForStmt:
+		if n.Cond != nil {
+			return nil
+		}
+		// unconditional loop
+		return w
+	}
+
+	return w
+}
+
+func (w *lintUnconditionalRecursionRule) updateFuncStatus(node ast.Node) {
+	if node == nil || w.currentFunc == nil || w.currentFunc.seenConditionalExit {
+		return
+	}
+
+	w.currentFunc.seenConditionalExit = w.hasControlExit(node)
+}
+
+var exitFunctions = map[string]map[string]bool{
+	"os":      map[string]bool{"Exit": true},
+	"syscall": map[string]bool{"Exit": true},
+	"log": map[string]bool{
+		"Fatal":   true,
+		"Fatalf":  true,
+		"Fatalln": true,
+		"Panic":   true,
+		"Panicf":  true,
+		"Panicln": true,
+	},
+}
+
+func (w *lintUnconditionalRecursionRule) hasControlExit(node ast.Node) bool {
+	// isExit returns true if the given node makes control exit the function
+	isExit := func(node ast.Node) bool {
+		switch n := node.(type) {
+		case *ast.ReturnStmt:
+			return true
+		case *ast.CallExpr:
+			if isIdent(n.Fun, "panic") {
+				return true
+			}
+			se, ok := n.Fun.(*ast.SelectorExpr)
+			if !ok {
+				return false
+			}
+
+			id, ok := se.X.(*ast.Ident)
+			if !ok {
+				return false
+			}
+
+			fn := se.Sel.Name
+			pkg := id.Name
+			if exitFunctions[pkg] != nil && exitFunctions[pkg][fn] { // it's a call to an exit function
+				return true
+			}
+		}
+
+		return false
+	}
+
+	return len(pick(node, isExit, nil)) != 0
+}

vendor/github.com/mgechev/revive/rule/unexported-naming.go

@@ -0,0 +1,115 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// UnexportedNamingRule lints wrongly named unexported symbols.
+type UnexportedNamingRule struct{}
+
+// Apply applies the rule to given file.
+func (r *UnexportedNamingRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	ba := &unexportablenamingLinter{onFailure}
+	ast.Walk(ba, file.AST)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (r *UnexportedNamingRule) Name() string {
+	return "unexported-naming"
+}
+
+type unexportablenamingLinter struct {
+	onFailure func(lint.Failure)
+}
+
+func (unl unexportablenamingLinter) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		unl.lintFunction(n.Type, n.Body)
+		return nil
+	case *ast.FuncLit:
+		unl.lintFunction(n.Type, n.Body)
+
+		return nil
+	case *ast.AssignStmt:
+		if n.Tok != token.DEFINE {
+			return nil
+		}
+
+		ids := []*ast.Ident{}
+		for _, e := range n.Lhs {
+			id, ok := e.(*ast.Ident)
+			if !ok {
+				continue
+			}
+			ids = append(ids, id)
+		}
+
+		unl.lintIDs(ids)
+
+	case *ast.DeclStmt:
+		gd, ok := n.Decl.(*ast.GenDecl)
+		if !ok {
+			return nil
+		}
+
+		if len(gd.Specs) < 1 {
+			return nil
+		}
+
+		vs, ok := gd.Specs[0].(*ast.ValueSpec)
+		if !ok {
+			return nil
+		}
+
+		unl.lintIDs(vs.Names)
+	}
+
+	return unl
+}
+
+func (unl unexportablenamingLinter) lintFunction(ft *ast.FuncType, body *ast.BlockStmt) {
+	unl.lintFields(ft.Params)
+	unl.lintFields(ft.Results)
+
+	if body != nil {
+		ast.Walk(unl, body)
+	}
+}
+
+func (unl unexportablenamingLinter) lintFields(fields *ast.FieldList) {
+	if fields == nil {
+		return
+	}
+
+	ids := []*ast.Ident{}
+	for _, field := range fields.List {
+		ids = append(ids, field.Names...)
+	}
+
+	unl.lintIDs(ids)
+}
+
+func (unl unexportablenamingLinter) lintIDs(ids []*ast.Ident) {
+	for _, id := range ids {
+		if id.IsExported() {
+			unl.onFailure(lint.Failure{
+				Node:       id,
+				Confidence: 1,
+				Category:   "naming",
+				Failure:    fmt.Sprintf("the symbol %s is local, its name should start with a lowercase letter", id.String()),
+			})
+		}
+	}
+}

vendor/github.com/mgechev/revive/rule/unused-receiver.go

@@ -11,7 +11,7 @@ import (
 type UnusedReceiverRule struct{}
 
 // Apply applies the rule to given file.
-func (_ *UnusedReceiverRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+func (*UnusedReceiverRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
 	var failures []lint.Failure
 
 	onFailure := func(failure lint.Failure) {
@@ -26,7 +26,7 @@ func (_ *UnusedReceiverRule) Apply(file *lint.File, _ lint.Arguments) []lint.Fai
 }
 
 // Name returns the rule name.
-func (_ *UnusedReceiverRule) Name() string {
+func (*UnusedReceiverRule) Name() string {
 	return "unused-receiver"
 }
 

vendor/github.com/mgechev/revive/rule/utils.go

@@ -182,8 +182,8 @@ func isExprABooleanLit(n ast.Node) (lexeme string, ok bool) {
 	return oper.Name, (oper.Name == trueName || oper.Name == falseName)
 }
 
-// gofmt returns a string representation of the expression.
-func gofmt(x ast.Expr) string {
+// gofmt returns a string representation of an AST subtree.
+func gofmt(x interface{}) string {
 	buf := bytes.Buffer{}
 	fs := token.NewFileSet()
 	printer.Fprint(&buf, fs, x)