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How to use checkVarlens method of compiler Package

Best Syzkaller code snippet using compiler.checkVarlens

check.go

Source:check.go

...21	comp.checkUsed()22	comp.checkRecursion()23	comp.checkLenTargets()24	comp.checkConstructors()25	comp.checkVarlens()26}27func (comp *compiler) checkNames() {28	calls := make(map[string]*ast.Call)29	for _, decl := range comp.desc.Nodes {30		switch decl.(type) {31		case *ast.Resource, *ast.Struct:32			pos, typ, name := decl.Info()33			if reservedName[name] {34				comp.error(pos, "%v uses reserved name %v", typ, name)35				continue36			}37			if builtinTypes[name] != nil {38				comp.error(pos, "%v name %v conflicts with builtin type", typ, name)39				continue40			}41			if prev := comp.resources[name]; prev != nil {42				comp.error(pos, "type %v redeclared, previously declared as resource at %v",43					name, prev.Pos)44				continue45			}46			if prev := comp.structs[name]; prev != nil {47				_, typ, _ := prev.Info()48				comp.error(pos, "type %v redeclared, previously declared as %v at %v",49					name, typ, prev.Pos)50				continue51			}52			if res, ok := decl.(*ast.Resource); ok {53				comp.resources[name] = res54			} else if str, ok := decl.(*ast.Struct); ok {55				comp.structs[name] = str56			}57		case *ast.IntFlags:58			n := decl.(*ast.IntFlags)59			name := n.Name.Name60			if reservedName[name] {61				comp.error(n.Pos, "flags uses reserved name %v", name)62				continue63			}64			if prev := comp.intFlags[name]; prev != nil {65				comp.error(n.Pos, "flags %v redeclared, previously declared at %v",66					name, prev.Pos)67				continue68			}69			comp.intFlags[name] = n70		case *ast.StrFlags:71			n := decl.(*ast.StrFlags)72			name := n.Name.Name73			if reservedName[name] {74				comp.error(n.Pos, "string flags uses reserved name %v", name)75				continue76			}77			if prev := comp.strFlags[name]; prev != nil {78				comp.error(n.Pos, "string flags %v redeclared, previously declared at %v",79					name, prev.Pos)80				continue81			}82			comp.strFlags[name] = n83		case *ast.Call:84			c := decl.(*ast.Call)85			name := c.Name.Name86			if prev := calls[name]; prev != nil {87				comp.error(c.Pos, "syscall %v redeclared, previously declared at %v",88					name, prev.Pos)89			}90			calls[name] = c91		}92	}93}94func (comp *compiler) checkFields() {95	const maxArgs = 9 // executor does not support more96	for _, decl := range comp.desc.Nodes {97		switch n := decl.(type) {98		case *ast.Struct:99			_, typ, name := n.Info()100			fields := make(map[string]bool)101			for _, f := range n.Fields {102				fn := f.Name.Name103				if fn == "parent" {104					comp.error(f.Pos, "reserved field name %v in %v %v", fn, typ, name)105				}106				if fields[fn] {107					comp.error(f.Pos, "duplicate field %v in %v %v", fn, typ, name)108				}109				fields[fn] = true110			}111			if !n.IsUnion && len(n.Fields) < 1 {112				comp.error(n.Pos, "struct %v has no fields, need at least 1 field", name)113			}114			if n.IsUnion && len(n.Fields) < 2 {115				comp.error(n.Pos, "union %v has only %v field, need at least 2 fields",116					name, len(n.Fields))117			}118		case *ast.Call:119			name := n.Name.Name120			args := make(map[string]bool)121			for _, a := range n.Args {122				an := a.Name.Name123				if an == "parent" {124					comp.error(a.Pos, "reserved argument name %v in syscall %v",125						an, name)126				}127				if args[an] {128					comp.error(a.Pos, "duplicate argument %v in syscall %v",129						an, name)130				}131				args[an] = true132			}133			if len(n.Args) > maxArgs {134				comp.error(n.Pos, "syscall %v has %v arguments, allowed maximum is %v",135					name, len(n.Args), maxArgs)136			}137		}138	}139}140func (comp *compiler) checkTypes() {141	for _, decl := range comp.desc.Nodes {142		switch n := decl.(type) {143		case *ast.Resource:144			comp.checkType(n.Base, false, false, false, true)145		case *ast.Struct:146			for _, f := range n.Fields {147				comp.checkType(f.Type, false, false, !n.IsUnion, false)148			}149			comp.checkStruct(n)150		case *ast.Call:151			for _, a := range n.Args {152				comp.checkType(a.Type, true, false, false, false)153			}154			if n.Ret != nil {155				comp.checkType(n.Ret, true, true, false, false)156			}157		}158	}159}160func (comp *compiler) checkLenTargets() {161	for _, decl := range comp.desc.Nodes {162		switch n := decl.(type) {163		case *ast.Call:164			for _, arg := range n.Args {165				comp.checkLenType(arg.Type, arg.Name.Name, n.Args, nil, make(map[string]bool), true)166			}167		}168	}169}170func (comp *compiler) checkLenType(t *ast.Type, name string, fields []*ast.Field,171	parents []*ast.Struct, checked map[string]bool, isArg bool) {172	desc := comp.getTypeDesc(t)173	if desc == typeStruct {174		s := comp.structs[t.Ident]175		// Prune recursion, can happen even on correct tree via opt pointers.176		if checked[s.Name.Name] {177			return178		}179		checked[s.Name.Name] = true180		parents = append(parents, s)181		for _, fld := range s.Fields {182			comp.checkLenType(fld.Type, fld.Name.Name, s.Fields, parents, checked, false)183		}184		return185	}186	_, args, _ := comp.getArgsBase(t, "", prog.DirIn, isArg)187	for i, arg := range args {188		argDesc := desc.Args[i]189		if argDesc.Type == typeArgLenTarget {190			comp.checkLenTarget(t, name, arg.Ident, fields, parents)191		} else if argDesc.Type == typeArgType {192			comp.checkLenType(arg, name, fields, parents, checked, false)193		}194	}195}196func (comp *compiler) checkLenTarget(t *ast.Type, name, target string, fields []*ast.Field, parents []*ast.Struct) {197	if target == name {198		comp.error(t.Pos, "%v target %v refer to itself", t.Ident, target)199		return200	}201	if target == "parent" {202		if len(parents) == 0 {203			comp.error(t.Pos, "%v target %v does not exist", t.Ident, target)204		}205		return206	}207	for _, fld := range fields {208		if target != fld.Name.Name {209			continue210		}211		if fld.Type == t {212			comp.error(t.Pos, "%v target %v refer to itself", t.Ident, target)213		}214		return215	}216	for _, parent := range parents {217		if target == parent.Name.Name {218			return219		}220	}221	comp.error(t.Pos, "%v target %v does not exist", t.Ident, target)222}223func (comp *compiler) checkUsed() {224	for _, decl := range comp.desc.Nodes {225		switch n := decl.(type) {226		case *ast.Call:227			if n.NR == ^uint64(0) {228				break229			}230			for _, arg := range n.Args {231				comp.checkUsedType(arg.Type, true)232			}233			if n.Ret != nil {234				comp.checkUsedType(n.Ret, true)235			}236		}237	}238}239func (comp *compiler) checkUsedType(t *ast.Type, isArg bool) {240	if comp.used[t.Ident] {241		return242	}243	desc := comp.getTypeDesc(t)244	if desc == typeResource {245		r := comp.resources[t.Ident]246		for r != nil && !comp.used[r.Name.Name] {247			comp.used[r.Name.Name] = true248			r = comp.resources[r.Base.Ident]249		}250		return251	}252	if desc == typeStruct {253		comp.used[t.Ident] = true254		s := comp.structs[t.Ident]255		for _, fld := range s.Fields {256			comp.checkUsedType(fld.Type, false)257		}258		return259	}260	_, args, _ := comp.getArgsBase(t, "", prog.DirIn, isArg)261	for i, arg := range args {262		if desc.Args[i].Type == typeArgType {263			comp.checkUsedType(arg, false)264		}265	}266}267type structDir struct {268	Struct string269	Dir    prog.Dir270}271func (comp *compiler) checkConstructors() {272	ctors := make(map[string]bool) // resources for which we have ctors273	checked := make(map[structDir]bool)274	for _, decl := range comp.desc.Nodes {275		switch n := decl.(type) {276		case *ast.Call:277			for _, arg := range n.Args {278				comp.checkTypeCtors(arg.Type, prog.DirIn, true, ctors, checked)279			}280			if n.Ret != nil {281				comp.checkTypeCtors(n.Ret, prog.DirOut, true, ctors, checked)282			}283		}284	}285	for _, decl := range comp.desc.Nodes {286		switch n := decl.(type) {287		case *ast.Resource:288			name := n.Name.Name289			if !ctors[name] && comp.used[name] {290				comp.error(n.Pos, "resource %v can't be created"+291					" (never mentioned as a syscall return value or output argument/field)",292					name)293			}294		}295	}296}297func (comp *compiler) checkTypeCtors(t *ast.Type, dir prog.Dir, isArg bool,298	ctors map[string]bool, checked map[structDir]bool) {299	desc := comp.getTypeDesc(t)300	if desc == typeResource {301		// TODO(dvyukov): consider changing this to "dir == prog.DirOut".302		// We have few questionable cases where resources can be created303		// only by inout struct fields. These structs should be split304		// into two different structs: one is in and second is out.305		// But that will require attaching dir to individual fields.306		if dir != prog.DirIn {307			r := comp.resources[t.Ident]308			for r != nil && !ctors[r.Name.Name] {309				ctors[r.Name.Name] = true310				r = comp.resources[r.Base.Ident]311			}312		}313		return314	}315	if desc == typeStruct {316		s := comp.structs[t.Ident]317		name := s.Name.Name318		key := structDir{name, dir}319		if checked[key] {320			return321		}322		checked[key] = true323		for _, fld := range s.Fields {324			comp.checkTypeCtors(fld.Type, dir, false, ctors, checked)325		}326		return327	}328	if desc == typePtr {329		dir = genDir(t.Args[0])330	}331	_, args, _ := comp.getArgsBase(t, "", dir, isArg)332	for i, arg := range args {333		if desc.Args[i].Type == typeArgType {334			comp.checkTypeCtors(arg, dir, false, ctors, checked)335		}336	}337}338func (comp *compiler) checkRecursion() {339	checked := make(map[string]bool)340	for _, decl := range comp.desc.Nodes {341		switch n := decl.(type) {342		case *ast.Resource:343			comp.checkResourceRecursion(n)344		case *ast.Struct:345			var path []pathElem346			comp.checkStructRecursion(checked, n, path)347		}348	}349}350func (comp *compiler) checkResourceRecursion(n *ast.Resource) {351	var seen []string352	for n != nil {353		if arrayContains(seen, n.Name.Name) {354			chain := ""355			for _, r := range seen {356				chain += r + "->"357			}358			chain += n.Name.Name359			comp.error(n.Pos, "recursive resource %v", chain)360			return361		}362		seen = append(seen, n.Name.Name)363		n = comp.resources[n.Base.Ident]364	}365}366type pathElem struct {367	Pos    ast.Pos368	Struct string369	Field  string370}371func (comp *compiler) checkStructRecursion(checked map[string]bool, n *ast.Struct, path []pathElem) {372	name := n.Name.Name373	if checked[name] {374		return375	}376	for i, elem := range path {377		if elem.Struct != name {378			continue379		}380		path = path[i:]381		str := ""382		for _, elem := range path {383			str += fmt.Sprintf("%v.%v -> ", elem.Struct, elem.Field)384		}385		str += name386		comp.error(path[0].Pos, "recursive declaration: %v (mark some pointers as opt)", str)387		checked[name] = true388		return389	}390	for _, f := range n.Fields {391		path = append(path, pathElem{392			Pos:    f.Pos,393			Struct: name,394			Field:  f.Name.Name,395		})396		comp.recurseField(checked, f.Type, path)397		path = path[:len(path)-1]398	}399	checked[name] = true400}401func (comp *compiler) recurseField(checked map[string]bool, t *ast.Type, path []pathElem) {402	desc := comp.getTypeDesc(t)403	if desc == typeStruct {404		comp.checkStructRecursion(checked, comp.structs[t.Ident], path)405		return406	}407	_, args, base := comp.getArgsBase(t, "", prog.DirIn, false)408	if desc == typePtr && base.IsOptional {409		return // optional pointers prune recursion410	}411	for i, arg := range args {412		if desc.Args[i].Type == typeArgType {413			comp.recurseField(checked, arg, path)414		}415	}416}417func (comp *compiler) checkStruct(n *ast.Struct) {418	if n.IsUnion {419		comp.parseUnionAttrs(n)420	} else {421		comp.parseStructAttrs(n)422	}423}424func (comp *compiler) checkType(t *ast.Type, isArg, isRet, isStruct, isResourceBase bool) {425	if unexpected, _, ok := checkTypeKind(t, kindIdent); !ok {426		comp.error(t.Pos, "unexpected %v, expect type", unexpected)427		return428	}429	desc := comp.getTypeDesc(t)430	if desc == nil {431		comp.error(t.Pos, "unknown type %v", t.Ident)432		return433	}434	if t.HasColon {435		if !desc.AllowColon {436			comp.error(t.Pos2, "unexpected ':'")437			return438		}439		if !isStruct {440			comp.error(t.Pos2, "unexpected ':', only struct fields can be bitfields")441			return442		}443	}444	if isRet && (!desc.CanBeArg || desc.CantBeRet) {445		comp.error(t.Pos, "%v can't be syscall return", t.Ident)446		return447	}448	if isArg && !desc.CanBeArg {449		comp.error(t.Pos, "%v can't be syscall argument", t.Ident)450		return451	}452	if isResourceBase && !desc.ResourceBase {453		comp.error(t.Pos, "%v can't be resource base (int types can)", t.Ident)454		return455	}456	args, opt := removeOpt(t)457	if opt && (desc.CantBeOpt || isResourceBase) {458		what := "resource base"459		if desc.CantBeOpt {460			what = t.Ident461		}462		pos := t.Args[len(t.Args)-1].Pos463		comp.error(pos, "%v can't be marked as opt", what)464		return465	}466	addArgs := 0467	needBase := !isArg && desc.NeedBase468	if needBase {469		addArgs++ // last arg must be base type, e.g. const[0, int32]470	}471	if len(args) > len(desc.Args)+addArgs || len(args) < len(desc.Args)-desc.OptArgs+addArgs {472		comp.error(t.Pos, "wrong number of arguments for type %v, expect %v",473			t.Ident, expectedTypeArgs(desc, needBase))474		return475	}476	if needBase {477		base := args[len(args)-1]478		args = args[:len(args)-1]479		comp.checkTypeArg(t, base, typeArgBase)480	}481	err0 := comp.errors482	for i, arg := range args {483		if desc.Args[i].Type == typeArgType {484			comp.checkType(arg, false, isRet, false, false)485		} else {486			comp.checkTypeArg(t, arg, desc.Args[i])487		}488	}489	if err0 != comp.errors {490		return491	}492	if desc.Check != nil {493		_, args, base := comp.getArgsBase(t, "", prog.DirIn, isArg)494		desc.Check(comp, t, args, base)495	}496}497func (comp *compiler) checkTypeArg(t, arg *ast.Type, argDesc namedArg) {498	desc := argDesc.Type499	if len(desc.Names) != 0 {500		if unexpected, _, ok := checkTypeKind(arg, kindIdent); !ok {501			comp.error(arg.Pos, "unexpected %v for %v argument of %v type, expect %+v",502				unexpected, argDesc.Name, t.Ident, desc.Names)503			return504		}505		if !arrayContains(desc.Names, arg.Ident) {506			comp.error(arg.Pos, "unexpected value %v for %v argument of %v type, expect %+v",507				arg.Ident, argDesc.Name, t.Ident, desc.Names)508			return509		}510	} else {511		if unexpected, expect, ok := checkTypeKind(arg, desc.Kind); !ok {512			comp.error(arg.Pos, "unexpected %v for %v argument of %v type, expect %v",513				unexpected, argDesc.Name, t.Ident, expect)514			return515		}516	}517	if !desc.AllowColon && arg.HasColon {518		comp.error(arg.Pos2, "unexpected ':'")519		return520	}521	if desc.Check != nil {522		desc.Check(comp, arg)523	}524}525func expectedTypeArgs(desc *typeDesc, needBase bool) string {526	expect := ""527	for i, arg := range desc.Args {528		if expect != "" {529			expect += ", "530		}531		opt := i >= len(desc.Args)-desc.OptArgs532		if opt {533			expect += "["534		}535		expect += arg.Name536		if opt {537			expect += "]"538		}539	}540	if needBase {541		if expect != "" {542			expect += ", "543		}544		expect += typeArgBase.Name545	}546	if !desc.CantBeOpt {547		if expect != "" {548			expect += ", "549		}550		expect += "[opt]"551	}552	if expect == "" {553		expect = "no arguments"554	}555	return expect556}557func checkTypeKind(t *ast.Type, kind int) (unexpected string, expect string, ok bool) {558	switch {559	case kind == kindAny:560		ok = true561	case t.String != "":562		ok = kind == kindString563		if !ok {564			unexpected = fmt.Sprintf("string %q", t.String)565		}566	case t.Ident != "":567		ok = kind == kindIdent568		if !ok {569			unexpected = fmt.Sprintf("identifier %v", t.Ident)570		}571	default:572		ok = kind == kindInt573		if !ok {574			unexpected = fmt.Sprintf("int %v", t.Value)575		}576	}577	if !ok {578		switch kind {579		case kindString:580			expect = "string"581		case kindIdent:582			expect = "identifier"583		case kindInt:584			expect = "int"585		}586	}587	return588}589func (comp *compiler) checkVarlens() {590	for _, decl := range comp.desc.Nodes {591		switch n := decl.(type) {592		case *ast.Struct:593			comp.checkVarlen(n)594		}595	}596}597func (comp *compiler) isVarlen(t *ast.Type) bool {598	desc, args, base := comp.getArgsBase(t, "", prog.DirIn, false)599	return desc.Varlen != nil && desc.Varlen(comp, t, args, base)600}601func (comp *compiler) checkVarlen(n *ast.Struct) {602	// Non-varlen unions can't have varlen fields.603	// Non-packed structs can't have varlen fields in the middle....

checkVarlens

Using AI Code Generation

1import (2func main() {3	compiler := compiler.NewCompiler()4	compiler.CheckVarlens()5	fmt.Println("CheckVarlens method executed successfully")6}

checkVarlens

Using AI Code Generation

1import (2func main() {3 c := compiler.NewCompiler()4 c.CheckVarlens()5 fmt.Println("Done")6}

checkVarlens

Using AI Code Generation

1import (2func main() {3	compilerObj := compiler.New()4	pretty.Println(compilerObj.CheckVarlens([]string{"abc", "de", "fgh"}))5	fmt.Println(compilerObj.CheckVarlens([]string{"abc", "", "fgh"}))6}

checkVarlens

Using AI Code Generation

1import (2func main() {3 compiler := new(Compiler.Compiler)4 compiler.CheckVarlens()5 fmt.Println("Done")6}

checkVarlens

Using AI Code Generation

1import (2func main() {3	comp := compiler.NewCompiler()4	vars := []string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"}5	varlens := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}6	comp.CheckVarlens(vars, varlens)7	fmt.Println("Length of the variable list: ", len(comp.Varlist))8	fmt.Println("Length of the variable length list: ", len(comp.Varlens))9}

checkVarlens

Using AI Code Generation

1import "fmt"2import "mycompiler"3func main() {4  var k []int = []int{1,2,3,4}5  var l []int = []int{1,2,3,4,5}6  var m [5]int = [5]int{1,2,3,4,5}7  var n [5]int = [5]int{1,2,3,4,5}8  var o map[int]string = map[int]string{1:"one",2:"two"}9  var p map[int]string = map[int]string{1:"one",2:"two",3:"three"}10  var q chan int = make(chan int)11  var r chan int = make(chan int)12  var s func() int = func() int {return 10}13  var t func() int = func() int {return 10}14  var u interface{} = 1015  var v interface{} = 1016  var w interface{} = "hello"17  var x interface{} = "hello"18  var y interface{} = 10.219  var z interface{} = 10.220  var x1 []int = []int{1,2,3,4}21  var y1 []int = []int{1,2,3,4,5}22  var z1 []int = []int{1,2,3,4}23  var x2 [5]int = [5]int{1,2,3,4,5}24  var y2 [5]int = [5]int{1,2,3,4,5}25  var z2 [5]int = [5]int{1,2,3,4,5}26  var x3 map[int]string = map[int]string{1:"one",2:"two"}27  var y3 map[int]string = map[int]string{1:"one",2:"two",3:"three"}

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