mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-15 08:23:34 +01:00
7d7fbf890e
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/203 Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/38
3361 lines
88 KiB
Go
3361 lines
88 KiB
Go
// Package staticcheck contains a linter for Go source code.
|
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package staticcheck // import "honnef.co/go/tools/staticcheck"
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import (
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"fmt"
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"go/ast"
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"go/constant"
|
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"go/token"
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"go/types"
|
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htmltemplate "html/template"
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"net/http"
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"reflect"
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"regexp"
|
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"regexp/syntax"
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"sort"
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"strconv"
|
||
"strings"
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texttemplate "text/template"
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"unicode"
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|
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. "honnef.co/go/tools/arg"
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"honnef.co/go/tools/deprecated"
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"honnef.co/go/tools/facts"
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"honnef.co/go/tools/functions"
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"honnef.co/go/tools/internal/passes/buildssa"
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"honnef.co/go/tools/internal/sharedcheck"
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"honnef.co/go/tools/lint"
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. "honnef.co/go/tools/lint/lintdsl"
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"honnef.co/go/tools/printf"
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||
"honnef.co/go/tools/ssa"
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||
"honnef.co/go/tools/ssautil"
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||
"honnef.co/go/tools/staticcheck/vrp"
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|
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"golang.org/x/tools/go/analysis"
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"golang.org/x/tools/go/analysis/passes/inspect"
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"golang.org/x/tools/go/ast/astutil"
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"golang.org/x/tools/go/ast/inspector"
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"golang.org/x/tools/go/types/typeutil"
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)
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func validRegexp(call *Call) {
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arg := call.Args[0]
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||
err := ValidateRegexp(arg.Value)
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||
if err != nil {
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arg.Invalid(err.Error())
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||
}
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||
}
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||
|
||
type runeSlice []rune
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||
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||
func (rs runeSlice) Len() int { return len(rs) }
|
||
func (rs runeSlice) Less(i int, j int) bool { return rs[i] < rs[j] }
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func (rs runeSlice) Swap(i int, j int) { rs[i], rs[j] = rs[j], rs[i] }
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||
|
||
func utf8Cutset(call *Call) {
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arg := call.Args[1]
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if InvalidUTF8(arg.Value) {
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arg.Invalid(MsgInvalidUTF8)
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}
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}
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||
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||
func uniqueCutset(call *Call) {
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arg := call.Args[1]
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if !UniqueStringCutset(arg.Value) {
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arg.Invalid(MsgNonUniqueCutset)
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||
}
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||
}
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func unmarshalPointer(name string, arg int) CallCheck {
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||
return func(call *Call) {
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if !Pointer(call.Args[arg].Value) {
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call.Args[arg].Invalid(fmt.Sprintf("%s expects to unmarshal into a pointer, but the provided value is not a pointer", name))
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}
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}
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||
}
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||
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func pointlessIntMath(call *Call) {
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if ConvertedFromInt(call.Args[0].Value) {
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call.Invalid(fmt.Sprintf("calling %s on a converted integer is pointless", CallName(call.Instr.Common())))
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}
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}
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||
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||
func checkValidHostPort(arg int) CallCheck {
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||
return func(call *Call) {
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||
if !ValidHostPort(call.Args[arg].Value) {
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call.Args[arg].Invalid(MsgInvalidHostPort)
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||
}
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||
}
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||
}
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||
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||
var (
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checkRegexpRules = map[string]CallCheck{
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||
"regexp.MustCompile": validRegexp,
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"regexp.Compile": validRegexp,
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"regexp.Match": validRegexp,
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"regexp.MatchReader": validRegexp,
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||
"regexp.MatchString": validRegexp,
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||
}
|
||
|
||
checkTimeParseRules = map[string]CallCheck{
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||
"time.Parse": func(call *Call) {
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||
arg := call.Args[Arg("time.Parse.layout")]
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||
err := ValidateTimeLayout(arg.Value)
|
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if err != nil {
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arg.Invalid(err.Error())
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}
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},
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||
}
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||
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checkEncodingBinaryRules = map[string]CallCheck{
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||
"encoding/binary.Write": func(call *Call) {
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||
arg := call.Args[Arg("encoding/binary.Write.data")]
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if !CanBinaryMarshal(call.Pass, arg.Value) {
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arg.Invalid(fmt.Sprintf("value of type %s cannot be used with binary.Write", arg.Value.Value.Type()))
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}
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},
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}
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checkURLsRules = map[string]CallCheck{
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||
"net/url.Parse": func(call *Call) {
|
||
arg := call.Args[Arg("net/url.Parse.rawurl")]
|
||
err := ValidateURL(arg.Value)
|
||
if err != nil {
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arg.Invalid(err.Error())
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||
}
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},
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||
}
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||
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checkSyncPoolValueRules = map[string]CallCheck{
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"(*sync.Pool).Put": func(call *Call) {
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||
arg := call.Args[Arg("(*sync.Pool).Put.x")]
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||
typ := arg.Value.Value.Type()
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if !IsPointerLike(typ) {
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arg.Invalid("argument should be pointer-like to avoid allocations")
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}
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},
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||
}
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||
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checkRegexpFindAllRules = map[string]CallCheck{
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"(*regexp.Regexp).FindAll": RepeatZeroTimes("a FindAll method", 1),
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||
"(*regexp.Regexp).FindAllIndex": RepeatZeroTimes("a FindAll method", 1),
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||
"(*regexp.Regexp).FindAllString": RepeatZeroTimes("a FindAll method", 1),
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||
"(*regexp.Regexp).FindAllStringIndex": RepeatZeroTimes("a FindAll method", 1),
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||
"(*regexp.Regexp).FindAllStringSubmatch": RepeatZeroTimes("a FindAll method", 1),
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||
"(*regexp.Regexp).FindAllStringSubmatchIndex": RepeatZeroTimes("a FindAll method", 1),
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"(*regexp.Regexp).FindAllSubmatch": RepeatZeroTimes("a FindAll method", 1),
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"(*regexp.Regexp).FindAllSubmatchIndex": RepeatZeroTimes("a FindAll method", 1),
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}
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checkUTF8CutsetRules = map[string]CallCheck{
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||
"strings.IndexAny": utf8Cutset,
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"strings.LastIndexAny": utf8Cutset,
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"strings.ContainsAny": utf8Cutset,
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"strings.Trim": utf8Cutset,
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"strings.TrimLeft": utf8Cutset,
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"strings.TrimRight": utf8Cutset,
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}
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checkUniqueCutsetRules = map[string]CallCheck{
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"strings.Trim": uniqueCutset,
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"strings.TrimLeft": uniqueCutset,
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"strings.TrimRight": uniqueCutset,
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}
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checkUnmarshalPointerRules = map[string]CallCheck{
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"encoding/xml.Unmarshal": unmarshalPointer("xml.Unmarshal", 1),
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"(*encoding/xml.Decoder).Decode": unmarshalPointer("Decode", 0),
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"(*encoding/xml.Decoder).DecodeElement": unmarshalPointer("DecodeElement", 0),
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"encoding/json.Unmarshal": unmarshalPointer("json.Unmarshal", 1),
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"(*encoding/json.Decoder).Decode": unmarshalPointer("Decode", 0),
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}
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checkUnbufferedSignalChanRules = map[string]CallCheck{
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"os/signal.Notify": func(call *Call) {
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arg := call.Args[Arg("os/signal.Notify.c")]
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if UnbufferedChannel(arg.Value) {
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arg.Invalid("the channel used with signal.Notify should be buffered")
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}
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},
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}
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checkMathIntRules = map[string]CallCheck{
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"math.Ceil": pointlessIntMath,
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"math.Floor": pointlessIntMath,
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"math.IsNaN": pointlessIntMath,
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"math.Trunc": pointlessIntMath,
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"math.IsInf": pointlessIntMath,
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}
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checkStringsReplaceZeroRules = map[string]CallCheck{
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"strings.Replace": RepeatZeroTimes("strings.Replace", 3),
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"bytes.Replace": RepeatZeroTimes("bytes.Replace", 3),
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}
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||
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checkListenAddressRules = map[string]CallCheck{
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"net/http.ListenAndServe": checkValidHostPort(0),
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"net/http.ListenAndServeTLS": checkValidHostPort(0),
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}
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checkBytesEqualIPRules = map[string]CallCheck{
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"bytes.Equal": func(call *Call) {
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if ConvertedFrom(call.Args[Arg("bytes.Equal.a")].Value, "net.IP") &&
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ConvertedFrom(call.Args[Arg("bytes.Equal.b")].Value, "net.IP") {
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call.Invalid("use net.IP.Equal to compare net.IPs, not bytes.Equal")
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}
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},
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}
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checkRegexpMatchLoopRules = map[string]CallCheck{
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"regexp.Match": loopedRegexp("regexp.Match"),
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"regexp.MatchReader": loopedRegexp("regexp.MatchReader"),
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"regexp.MatchString": loopedRegexp("regexp.MatchString"),
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}
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||
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checkNoopMarshal = map[string]CallCheck{
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// TODO(dh): should we really flag XML? Even an empty struct
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// produces a non-zero amount of data, namely its type name.
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// Let's see if we encounter any false positives.
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//
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// Also, should we flag gob?
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"encoding/json.Marshal": checkNoopMarshalImpl(Arg("json.Marshal.v"), "MarshalJSON", "MarshalText"),
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"encoding/xml.Marshal": checkNoopMarshalImpl(Arg("xml.Marshal.v"), "MarshalXML", "MarshalText"),
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||
"(*encoding/json.Encoder).Encode": checkNoopMarshalImpl(Arg("(*encoding/json.Encoder).Encode.v"), "MarshalJSON", "MarshalText"),
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||
"(*encoding/xml.Encoder).Encode": checkNoopMarshalImpl(Arg("(*encoding/xml.Encoder).Encode.v"), "MarshalXML", "MarshalText"),
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||
|
||
"encoding/json.Unmarshal": checkNoopMarshalImpl(Arg("json.Unmarshal.v"), "UnmarshalJSON", "UnmarshalText"),
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||
"encoding/xml.Unmarshal": checkNoopMarshalImpl(Arg("xml.Unmarshal.v"), "UnmarshalXML", "UnmarshalText"),
|
||
"(*encoding/json.Decoder).Decode": checkNoopMarshalImpl(Arg("(*encoding/json.Decoder).Decode.v"), "UnmarshalJSON", "UnmarshalText"),
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||
"(*encoding/xml.Decoder).Decode": checkNoopMarshalImpl(Arg("(*encoding/xml.Decoder).Decode.v"), "UnmarshalXML", "UnmarshalText"),
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}
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||
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checkUnsupportedMarshal = map[string]CallCheck{
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||
"encoding/json.Marshal": checkUnsupportedMarshalImpl(Arg("json.Marshal.v"), "json", "MarshalJSON", "MarshalText"),
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||
"encoding/xml.Marshal": checkUnsupportedMarshalImpl(Arg("xml.Marshal.v"), "xml", "MarshalXML", "MarshalText"),
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||
"(*encoding/json.Encoder).Encode": checkUnsupportedMarshalImpl(Arg("(*encoding/json.Encoder).Encode.v"), "json", "MarshalJSON", "MarshalText"),
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||
"(*encoding/xml.Encoder).Encode": checkUnsupportedMarshalImpl(Arg("(*encoding/xml.Encoder).Encode.v"), "xml", "MarshalXML", "MarshalText"),
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||
}
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||
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checkAtomicAlignment = map[string]CallCheck{
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||
"sync/atomic.AddInt64": checkAtomicAlignmentImpl,
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||
"sync/atomic.AddUint64": checkAtomicAlignmentImpl,
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||
"sync/atomic.CompareAndSwapInt64": checkAtomicAlignmentImpl,
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||
"sync/atomic.CompareAndSwapUint64": checkAtomicAlignmentImpl,
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||
"sync/atomic.LoadInt64": checkAtomicAlignmentImpl,
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||
"sync/atomic.LoadUint64": checkAtomicAlignmentImpl,
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||
"sync/atomic.StoreInt64": checkAtomicAlignmentImpl,
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||
"sync/atomic.StoreUint64": checkAtomicAlignmentImpl,
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||
"sync/atomic.SwapInt64": checkAtomicAlignmentImpl,
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||
"sync/atomic.SwapUint64": checkAtomicAlignmentImpl,
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||
}
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||
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||
// TODO(dh): detect printf wrappers
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checkPrintfRules = map[string]CallCheck{
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"fmt.Errorf": func(call *Call) { checkPrintfCall(call, 0, 1) },
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"fmt.Printf": func(call *Call) { checkPrintfCall(call, 0, 1) },
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"fmt.Sprintf": func(call *Call) { checkPrintfCall(call, 0, 1) },
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"fmt.Fprintf": func(call *Call) { checkPrintfCall(call, 1, 2) },
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}
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)
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func checkPrintfCall(call *Call, fIdx, vIdx int) {
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f := call.Args[fIdx]
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var args []ssa.Value
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switch v := call.Args[vIdx].Value.Value.(type) {
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||
case *ssa.Slice:
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||
var ok bool
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||
args, ok = ssautil.Vararg(v)
|
||
if !ok {
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||
// We don't know what the actual arguments to the function are
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return
|
||
}
|
||
case *ssa.Const:
|
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// nil, i.e. no arguments
|
||
default:
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||
// We don't know what the actual arguments to the function are
|
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return
|
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}
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checkPrintfCallImpl(call, f.Value.Value, args)
|
||
}
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||
|
||
type verbFlag int
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||
|
||
const (
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||
isInt verbFlag = 1 << iota
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||
isBool
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||
isFP
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||
isString
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||
isPointer
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||
isPseudoPointer
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||
isSlice
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||
isAny
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||
noRecurse
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||
)
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||
|
||
var verbs = [...]verbFlag{
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||
'b': isPseudoPointer | isInt | isFP,
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||
'c': isInt,
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'd': isPseudoPointer | isInt,
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||
'e': isFP,
|
||
'E': isFP,
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||
'f': isFP,
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||
'F': isFP,
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||
'g': isFP,
|
||
'G': isFP,
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||
'o': isPseudoPointer | isInt,
|
||
'p': isSlice | isPointer | noRecurse,
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||
'q': isInt | isString,
|
||
's': isString,
|
||
't': isBool,
|
||
'T': isAny,
|
||
'U': isInt,
|
||
'v': isAny,
|
||
'X': isPseudoPointer | isInt | isString,
|
||
'x': isPseudoPointer | isInt | isString,
|
||
}
|
||
|
||
func checkPrintfCallImpl(call *Call, f ssa.Value, args []ssa.Value) {
|
||
var msCache *typeutil.MethodSetCache
|
||
if f.Parent() != nil {
|
||
msCache = &f.Parent().Prog.MethodSets
|
||
}
|
||
|
||
elem := func(T types.Type, verb rune) ([]types.Type, bool) {
|
||
if verbs[verb]&noRecurse != 0 {
|
||
return []types.Type{T}, false
|
||
}
|
||
switch T := T.(type) {
|
||
case *types.Slice:
|
||
if verbs[verb]&isSlice != 0 {
|
||
return []types.Type{T}, false
|
||
}
|
||
if verbs[verb]&isString != 0 && IsType(T.Elem().Underlying(), "byte") {
|
||
return []types.Type{T}, false
|
||
}
|
||
return []types.Type{T.Elem()}, true
|
||
case *types.Map:
|
||
key := T.Key()
|
||
val := T.Elem()
|
||
return []types.Type{key, val}, true
|
||
case *types.Struct:
|
||
out := make([]types.Type, 0, T.NumFields())
|
||
for i := 0; i < T.NumFields(); i++ {
|
||
out = append(out, T.Field(i).Type())
|
||
}
|
||
return out, true
|
||
case *types.Array:
|
||
return []types.Type{T.Elem()}, true
|
||
default:
|
||
return []types.Type{T}, false
|
||
}
|
||
}
|
||
isInfo := func(T types.Type, info types.BasicInfo) bool {
|
||
basic, ok := T.Underlying().(*types.Basic)
|
||
return ok && basic.Info()&info != 0
|
||
}
|
||
|
||
isStringer := func(T types.Type, ms *types.MethodSet) bool {
|
||
sel := ms.Lookup(nil, "String")
|
||
if sel == nil {
|
||
return false
|
||
}
|
||
fn, ok := sel.Obj().(*types.Func)
|
||
if !ok {
|
||
// should be unreachable
|
||
return false
|
||
}
|
||
sig := fn.Type().(*types.Signature)
|
||
if sig.Params().Len() != 0 {
|
||
return false
|
||
}
|
||
if sig.Results().Len() != 1 {
|
||
return false
|
||
}
|
||
if !IsType(sig.Results().At(0).Type(), "string") {
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
isError := func(T types.Type, ms *types.MethodSet) bool {
|
||
sel := ms.Lookup(nil, "Error")
|
||
if sel == nil {
|
||
return false
|
||
}
|
||
fn, ok := sel.Obj().(*types.Func)
|
||
if !ok {
|
||
// should be unreachable
|
||
return false
|
||
}
|
||
sig := fn.Type().(*types.Signature)
|
||
if sig.Params().Len() != 0 {
|
||
return false
|
||
}
|
||
if sig.Results().Len() != 1 {
|
||
return false
|
||
}
|
||
if !IsType(sig.Results().At(0).Type(), "string") {
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
|
||
isFormatter := func(T types.Type, ms *types.MethodSet) bool {
|
||
sel := ms.Lookup(nil, "Format")
|
||
if sel == nil {
|
||
return false
|
||
}
|
||
fn, ok := sel.Obj().(*types.Func)
|
||
if !ok {
|
||
// should be unreachable
|
||
return false
|
||
}
|
||
sig := fn.Type().(*types.Signature)
|
||
if sig.Params().Len() != 2 {
|
||
return false
|
||
}
|
||
// TODO(dh): check the types of the arguments for more
|
||
// precision
|
||
if sig.Results().Len() != 0 {
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
|
||
seen := map[types.Type]bool{}
|
||
var checkType func(verb rune, T types.Type, top bool) bool
|
||
checkType = func(verb rune, T types.Type, top bool) bool {
|
||
if top {
|
||
for k := range seen {
|
||
delete(seen, k)
|
||
}
|
||
}
|
||
if seen[T] {
|
||
return true
|
||
}
|
||
seen[T] = true
|
||
if int(verb) >= len(verbs) {
|
||
// Unknown verb
|
||
return true
|
||
}
|
||
|
||
flags := verbs[verb]
|
||
if flags == 0 {
|
||
// Unknown verb
|
||
return true
|
||
}
|
||
|
||
ms := msCache.MethodSet(T)
|
||
if isFormatter(T, ms) {
|
||
// the value is responsible for formatting itself
|
||
return true
|
||
}
|
||
|
||
if flags&isString != 0 && (isStringer(T, ms) || isError(T, ms)) {
|
||
// Check for stringer early because we're about to dereference
|
||
return true
|
||
}
|
||
|
||
T = T.Underlying()
|
||
if flags&(isPointer|isPseudoPointer) == 0 && top {
|
||
T = Dereference(T)
|
||
}
|
||
if flags&isPseudoPointer != 0 && top {
|
||
t := Dereference(T)
|
||
if _, ok := t.Underlying().(*types.Struct); ok {
|
||
T = t
|
||
}
|
||
}
|
||
|
||
if _, ok := T.(*types.Interface); ok {
|
||
// We don't know what's in the interface
|
||
return true
|
||
}
|
||
|
||
var info types.BasicInfo
|
||
if flags&isInt != 0 {
|
||
info |= types.IsInteger
|
||
}
|
||
if flags&isBool != 0 {
|
||
info |= types.IsBoolean
|
||
}
|
||
if flags&isFP != 0 {
|
||
info |= types.IsFloat | types.IsComplex
|
||
}
|
||
if flags&isString != 0 {
|
||
info |= types.IsString
|
||
}
|
||
|
||
if info != 0 && isInfo(T, info) {
|
||
return true
|
||
}
|
||
|
||
if flags&isString != 0 && (IsType(T, "[]byte") || isStringer(T, ms) || isError(T, ms)) {
|
||
return true
|
||
}
|
||
|
||
if flags&isPointer != 0 && IsPointerLike(T) {
|
||
return true
|
||
}
|
||
if flags&isPseudoPointer != 0 {
|
||
switch U := T.Underlying().(type) {
|
||
case *types.Pointer:
|
||
if !top {
|
||
return true
|
||
}
|
||
|
||
if _, ok := U.Elem().Underlying().(*types.Struct); !ok {
|
||
return true
|
||
}
|
||
case *types.Chan, *types.Signature:
|
||
return true
|
||
}
|
||
}
|
||
|
||
if flags&isSlice != 0 {
|
||
if _, ok := T.(*types.Slice); ok {
|
||
return true
|
||
}
|
||
}
|
||
|
||
if flags&isAny != 0 {
|
||
return true
|
||
}
|
||
|
||
elems, ok := elem(T.Underlying(), verb)
|
||
if !ok {
|
||
return false
|
||
}
|
||
for _, elem := range elems {
|
||
if !checkType(verb, elem, false) {
|
||
return false
|
||
}
|
||
}
|
||
|
||
return true
|
||
}
|
||
|
||
k, ok := f.(*ssa.Const)
|
||
if !ok {
|
||
return
|
||
}
|
||
actions, err := printf.Parse(constant.StringVal(k.Value))
|
||
if err != nil {
|
||
call.Invalid("couldn't parse format string")
|
||
return
|
||
}
|
||
|
||
ptr := 1
|
||
hasExplicit := false
|
||
|
||
checkStar := func(verb printf.Verb, star printf.Argument) bool {
|
||
if star, ok := star.(printf.Star); ok {
|
||
idx := 0
|
||
if star.Index == -1 {
|
||
idx = ptr
|
||
ptr++
|
||
} else {
|
||
hasExplicit = true
|
||
idx = star.Index
|
||
ptr = star.Index + 1
|
||
}
|
||
if idx == 0 {
|
||
call.Invalid(fmt.Sprintf("Printf format %s reads invalid arg 0; indices are 1-based", verb.Raw))
|
||
return false
|
||
}
|
||
if idx > len(args) {
|
||
call.Invalid(
|
||
fmt.Sprintf("Printf format %s reads arg #%d, but call has only %d args",
|
||
verb.Raw, idx, len(args)))
|
||
return false
|
||
}
|
||
if arg, ok := args[idx-1].(*ssa.MakeInterface); ok {
|
||
if !isInfo(arg.X.Type(), types.IsInteger) {
|
||
call.Invalid(fmt.Sprintf("Printf format %s reads non-int arg #%d as argument of *", verb.Raw, idx))
|
||
}
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
|
||
// We only report one problem per format string. Making a
|
||
// mistake with an index tends to invalidate all future
|
||
// implicit indices.
|
||
for _, action := range actions {
|
||
verb, ok := action.(printf.Verb)
|
||
if !ok {
|
||
continue
|
||
}
|
||
|
||
if !checkStar(verb, verb.Width) || !checkStar(verb, verb.Precision) {
|
||
return
|
||
}
|
||
|
||
off := ptr
|
||
if verb.Value != -1 {
|
||
hasExplicit = true
|
||
off = verb.Value
|
||
}
|
||
if off > len(args) {
|
||
call.Invalid(
|
||
fmt.Sprintf("Printf format %s reads arg #%d, but call has only %d args",
|
||
verb.Raw, off, len(args)))
|
||
return
|
||
} else if verb.Value == 0 && verb.Letter != '%' {
|
||
call.Invalid(fmt.Sprintf("Printf format %s reads invalid arg 0; indices are 1-based", verb.Raw))
|
||
return
|
||
} else if off != 0 {
|
||
arg, ok := args[off-1].(*ssa.MakeInterface)
|
||
if ok {
|
||
if !checkType(verb.Letter, arg.X.Type(), true) {
|
||
call.Invalid(fmt.Sprintf("Printf format %s has arg #%d of wrong type %s",
|
||
verb.Raw, ptr, args[ptr-1].(*ssa.MakeInterface).X.Type()))
|
||
return
|
||
}
|
||
}
|
||
}
|
||
|
||
switch verb.Value {
|
||
case -1:
|
||
// Consume next argument
|
||
ptr++
|
||
case 0:
|
||
// Don't consume any arguments
|
||
default:
|
||
ptr = verb.Value + 1
|
||
}
|
||
}
|
||
|
||
if !hasExplicit && ptr <= len(args) {
|
||
call.Invalid(fmt.Sprintf("Printf call needs %d args but has %d args", ptr-1, len(args)))
|
||
}
|
||
}
|
||
|
||
func checkAtomicAlignmentImpl(call *Call) {
|
||
sizes := call.Pass.TypesSizes
|
||
if sizes.Sizeof(types.Typ[types.Uintptr]) != 4 {
|
||
// Not running on a 32-bit platform
|
||
return
|
||
}
|
||
v, ok := call.Args[0].Value.Value.(*ssa.FieldAddr)
|
||
if !ok {
|
||
// TODO(dh): also check indexing into arrays and slices
|
||
return
|
||
}
|
||
T := v.X.Type().Underlying().(*types.Pointer).Elem().Underlying().(*types.Struct)
|
||
fields := make([]*types.Var, 0, T.NumFields())
|
||
for i := 0; i < T.NumFields() && i <= v.Field; i++ {
|
||
fields = append(fields, T.Field(i))
|
||
}
|
||
|
||
off := sizes.Offsetsof(fields)[v.Field]
|
||
if off%8 != 0 {
|
||
msg := fmt.Sprintf("address of non 64-bit aligned field %s passed to %s",
|
||
T.Field(v.Field).Name(),
|
||
CallName(call.Instr.Common()))
|
||
call.Invalid(msg)
|
||
}
|
||
}
|
||
|
||
func checkNoopMarshalImpl(argN int, meths ...string) CallCheck {
|
||
return func(call *Call) {
|
||
if IsGenerated(call.Pass, call.Instr.Pos()) {
|
||
return
|
||
}
|
||
arg := call.Args[argN]
|
||
T := arg.Value.Value.Type()
|
||
Ts, ok := Dereference(T).Underlying().(*types.Struct)
|
||
if !ok {
|
||
return
|
||
}
|
||
if Ts.NumFields() == 0 {
|
||
return
|
||
}
|
||
fields := FlattenFields(Ts)
|
||
for _, field := range fields {
|
||
if field.Var.Exported() {
|
||
return
|
||
}
|
||
}
|
||
// OPT(dh): we could use a method set cache here
|
||
ms := call.Instr.Parent().Prog.MethodSets.MethodSet(T)
|
||
// TODO(dh): we're not checking the signature, which can cause false negatives.
|
||
// This isn't a huge problem, however, since vet complains about incorrect signatures.
|
||
for _, meth := range meths {
|
||
if ms.Lookup(nil, meth) != nil {
|
||
return
|
||
}
|
||
}
|
||
arg.Invalid("struct doesn't have any exported fields, nor custom marshaling")
|
||
}
|
||
}
|
||
|
||
func checkUnsupportedMarshalImpl(argN int, tag string, meths ...string) CallCheck {
|
||
// TODO(dh): flag slices and maps of unsupported types
|
||
return func(call *Call) {
|
||
msCache := &call.Instr.Parent().Prog.MethodSets
|
||
|
||
arg := call.Args[argN]
|
||
T := arg.Value.Value.Type()
|
||
Ts, ok := Dereference(T).Underlying().(*types.Struct)
|
||
if !ok {
|
||
return
|
||
}
|
||
ms := msCache.MethodSet(T)
|
||
// TODO(dh): we're not checking the signature, which can cause false negatives.
|
||
// This isn't a huge problem, however, since vet complains about incorrect signatures.
|
||
for _, meth := range meths {
|
||
if ms.Lookup(nil, meth) != nil {
|
||
return
|
||
}
|
||
}
|
||
fields := FlattenFields(Ts)
|
||
for _, field := range fields {
|
||
if !(field.Var.Exported()) {
|
||
continue
|
||
}
|
||
if reflect.StructTag(field.Tag).Get(tag) == "-" {
|
||
continue
|
||
}
|
||
ms := msCache.MethodSet(field.Var.Type())
|
||
// TODO(dh): we're not checking the signature, which can cause false negatives.
|
||
// This isn't a huge problem, however, since vet complains about incorrect signatures.
|
||
for _, meth := range meths {
|
||
if ms.Lookup(nil, meth) != nil {
|
||
return
|
||
}
|
||
}
|
||
switch field.Var.Type().Underlying().(type) {
|
||
case *types.Chan, *types.Signature:
|
||
arg.Invalid(fmt.Sprintf("trying to marshal chan or func value, field %s", fieldPath(T, field.Path)))
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
func fieldPath(start types.Type, indices []int) string {
|
||
p := start.String()
|
||
for _, idx := range indices {
|
||
field := Dereference(start).Underlying().(*types.Struct).Field(idx)
|
||
start = field.Type()
|
||
p += "." + field.Name()
|
||
}
|
||
return p
|
||
}
|
||
|
||
func isInLoop(b *ssa.BasicBlock) bool {
|
||
sets := functions.FindLoops(b.Parent())
|
||
for _, set := range sets {
|
||
if set.Has(b) {
|
||
return true
|
||
}
|
||
}
|
||
return false
|
||
}
|
||
|
||
func CheckUntrappableSignal(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
if !IsCallToAnyAST(pass, call,
|
||
"os/signal.Ignore", "os/signal.Notify", "os/signal.Reset") {
|
||
return
|
||
}
|
||
for _, arg := range call.Args {
|
||
if conv, ok := arg.(*ast.CallExpr); ok && isName(pass, conv.Fun, "os.Signal") {
|
||
arg = conv.Args[0]
|
||
}
|
||
|
||
if isName(pass, arg, "os.Kill") || isName(pass, arg, "syscall.SIGKILL") {
|
||
ReportNodef(pass, arg, "%s cannot be trapped (did you mean syscall.SIGTERM?)", Render(pass, arg))
|
||
}
|
||
if isName(pass, arg, "syscall.SIGSTOP") {
|
||
ReportNodef(pass, arg, "%s signal cannot be trapped", Render(pass, arg))
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckTemplate(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
var kind string
|
||
if IsCallToAST(pass, call, "(*text/template.Template).Parse") {
|
||
kind = "text"
|
||
} else if IsCallToAST(pass, call, "(*html/template.Template).Parse") {
|
||
kind = "html"
|
||
} else {
|
||
return
|
||
}
|
||
sel := call.Fun.(*ast.SelectorExpr)
|
||
if !IsCallToAST(pass, sel.X, "text/template.New") &&
|
||
!IsCallToAST(pass, sel.X, "html/template.New") {
|
||
// TODO(dh): this is a cheap workaround for templates with
|
||
// different delims. A better solution with less false
|
||
// negatives would use data flow analysis to see where the
|
||
// template comes from and where it has been
|
||
return
|
||
}
|
||
s, ok := ExprToString(pass, call.Args[Arg("(*text/template.Template).Parse.text")])
|
||
if !ok {
|
||
return
|
||
}
|
||
var err error
|
||
switch kind {
|
||
case "text":
|
||
_, err = texttemplate.New("").Parse(s)
|
||
case "html":
|
||
_, err = htmltemplate.New("").Parse(s)
|
||
}
|
||
if err != nil {
|
||
// TODO(dominikh): whitelist other parse errors, if any
|
||
if strings.Contains(err.Error(), "unexpected") {
|
||
ReportNodef(pass, call.Args[Arg("(*text/template.Template).Parse.text")], "%s", err)
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckTimeSleepConstant(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
if !IsCallToAST(pass, call, "time.Sleep") {
|
||
return
|
||
}
|
||
lit, ok := call.Args[Arg("time.Sleep.d")].(*ast.BasicLit)
|
||
if !ok {
|
||
return
|
||
}
|
||
n, err := strconv.Atoi(lit.Value)
|
||
if err != nil {
|
||
return
|
||
}
|
||
if n == 0 || n > 120 {
|
||
// time.Sleep(0) is a seldom used pattern in concurrency
|
||
// tests. >120 might be intentional. 120 was chosen
|
||
// because the user could've meant 2 minutes.
|
||
return
|
||
}
|
||
recommendation := "time.Sleep(time.Nanosecond)"
|
||
if n != 1 {
|
||
recommendation = fmt.Sprintf("time.Sleep(%d * time.Nanosecond)", n)
|
||
}
|
||
ReportNodef(pass, call.Args[Arg("time.Sleep.d")],
|
||
"sleeping for %d nanoseconds is probably a bug. Be explicit if it isn't: %s", n, recommendation)
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckWaitgroupAdd(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
g := node.(*ast.GoStmt)
|
||
fun, ok := g.Call.Fun.(*ast.FuncLit)
|
||
if !ok {
|
||
return
|
||
}
|
||
if len(fun.Body.List) == 0 {
|
||
return
|
||
}
|
||
stmt, ok := fun.Body.List[0].(*ast.ExprStmt)
|
||
if !ok {
|
||
return
|
||
}
|
||
if IsCallToAST(pass, stmt.X, "(*sync.WaitGroup).Add") {
|
||
ReportNodef(pass, stmt, "should call %s before starting the goroutine to avoid a race",
|
||
Render(pass, stmt))
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.GoStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckInfiniteEmptyLoop(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
loop := node.(*ast.ForStmt)
|
||
if len(loop.Body.List) != 0 || loop.Post != nil {
|
||
return
|
||
}
|
||
|
||
if loop.Init != nil {
|
||
// TODO(dh): this isn't strictly necessary, it just makes
|
||
// the check easier.
|
||
return
|
||
}
|
||
// An empty loop is bad news in two cases: 1) The loop has no
|
||
// condition. In that case, it's just a loop that spins
|
||
// forever and as fast as it can, keeping a core busy. 2) The
|
||
// loop condition only consists of variable or field reads and
|
||
// operators on those. The only way those could change their
|
||
// value is with unsynchronised access, which constitutes a
|
||
// data race.
|
||
//
|
||
// If the condition contains any function calls, its behaviour
|
||
// is dynamic and the loop might terminate. Similarly for
|
||
// channel receives.
|
||
|
||
if loop.Cond != nil {
|
||
if hasSideEffects(loop.Cond) {
|
||
return
|
||
}
|
||
if ident, ok := loop.Cond.(*ast.Ident); ok {
|
||
if k, ok := pass.TypesInfo.ObjectOf(ident).(*types.Const); ok {
|
||
if !constant.BoolVal(k.Val()) {
|
||
// don't flag `for false {}` loops. They're a debug aid.
|
||
return
|
||
}
|
||
}
|
||
}
|
||
ReportNodef(pass, loop, "loop condition never changes or has a race condition")
|
||
}
|
||
ReportNodef(pass, loop, "this loop will spin, using 100%% CPU")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.ForStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckDeferInInfiniteLoop(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
mightExit := false
|
||
var defers []ast.Stmt
|
||
loop := node.(*ast.ForStmt)
|
||
if loop.Cond != nil {
|
||
return
|
||
}
|
||
fn2 := func(node ast.Node) bool {
|
||
switch stmt := node.(type) {
|
||
case *ast.ReturnStmt:
|
||
mightExit = true
|
||
return false
|
||
case *ast.BranchStmt:
|
||
// TODO(dominikh): if this sees a break in a switch or
|
||
// select, it doesn't check if it breaks the loop or
|
||
// just the select/switch. This causes some false
|
||
// negatives.
|
||
if stmt.Tok == token.BREAK {
|
||
mightExit = true
|
||
return false
|
||
}
|
||
case *ast.DeferStmt:
|
||
defers = append(defers, stmt)
|
||
case *ast.FuncLit:
|
||
// Don't look into function bodies
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
ast.Inspect(loop.Body, fn2)
|
||
if mightExit {
|
||
return
|
||
}
|
||
for _, stmt := range defers {
|
||
ReportNodef(pass, stmt, "defers in this infinite loop will never run")
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.ForStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckDubiousDeferInChannelRangeLoop(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
loop := node.(*ast.RangeStmt)
|
||
typ := pass.TypesInfo.TypeOf(loop.X)
|
||
_, ok := typ.Underlying().(*types.Chan)
|
||
if !ok {
|
||
return
|
||
}
|
||
fn2 := func(node ast.Node) bool {
|
||
switch stmt := node.(type) {
|
||
case *ast.DeferStmt:
|
||
ReportNodef(pass, stmt, "defers in this range loop won't run unless the channel gets closed")
|
||
case *ast.FuncLit:
|
||
// Don't look into function bodies
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
ast.Inspect(loop.Body, fn2)
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.RangeStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckTestMainExit(pass *analysis.Pass) (interface{}, error) {
|
||
var (
|
||
fnmain ast.Node
|
||
callsExit bool
|
||
callsRun bool
|
||
arg types.Object
|
||
)
|
||
fn := func(node ast.Node, push bool) bool {
|
||
if !push {
|
||
if fnmain != nil && node == fnmain {
|
||
if !callsExit && callsRun {
|
||
ReportNodef(pass, fnmain, "TestMain should call os.Exit to set exit code")
|
||
}
|
||
fnmain = nil
|
||
callsExit = false
|
||
callsRun = false
|
||
arg = nil
|
||
}
|
||
return true
|
||
}
|
||
|
||
switch node := node.(type) {
|
||
case *ast.FuncDecl:
|
||
if fnmain != nil {
|
||
return true
|
||
}
|
||
if !isTestMain(pass, node) {
|
||
return false
|
||
}
|
||
fnmain = node
|
||
arg = pass.TypesInfo.ObjectOf(node.Type.Params.List[0].Names[0])
|
||
return true
|
||
case *ast.CallExpr:
|
||
if IsCallToAST(pass, node, "os.Exit") {
|
||
callsExit = true
|
||
return false
|
||
}
|
||
sel, ok := node.Fun.(*ast.SelectorExpr)
|
||
if !ok {
|
||
return true
|
||
}
|
||
ident, ok := sel.X.(*ast.Ident)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if arg != pass.TypesInfo.ObjectOf(ident) {
|
||
return true
|
||
}
|
||
if sel.Sel.Name == "Run" {
|
||
callsRun = true
|
||
return false
|
||
}
|
||
return true
|
||
default:
|
||
// unreachable
|
||
return true
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Nodes([]ast.Node{(*ast.FuncDecl)(nil), (*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func isTestMain(pass *analysis.Pass, decl *ast.FuncDecl) bool {
|
||
if decl.Name.Name != "TestMain" {
|
||
return false
|
||
}
|
||
if len(decl.Type.Params.List) != 1 {
|
||
return false
|
||
}
|
||
arg := decl.Type.Params.List[0]
|
||
if len(arg.Names) != 1 {
|
||
return false
|
||
}
|
||
return IsOfType(pass, arg.Type, "*testing.M")
|
||
}
|
||
|
||
func CheckExec(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
if !IsCallToAST(pass, call, "os/exec.Command") {
|
||
return
|
||
}
|
||
val, ok := ExprToString(pass, call.Args[Arg("os/exec.Command.name")])
|
||
if !ok {
|
||
return
|
||
}
|
||
if !strings.Contains(val, " ") || strings.Contains(val, `\`) || strings.Contains(val, "/") {
|
||
return
|
||
}
|
||
ReportNodef(pass, call.Args[Arg("os/exec.Command.name")],
|
||
"first argument to exec.Command looks like a shell command, but a program name or path are expected")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckLoopEmptyDefault(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
loop := node.(*ast.ForStmt)
|
||
if len(loop.Body.List) != 1 || loop.Cond != nil || loop.Init != nil {
|
||
return
|
||
}
|
||
sel, ok := loop.Body.List[0].(*ast.SelectStmt)
|
||
if !ok {
|
||
return
|
||
}
|
||
for _, c := range sel.Body.List {
|
||
if comm, ok := c.(*ast.CommClause); ok && comm.Comm == nil && len(comm.Body) == 0 {
|
||
ReportNodef(pass, comm, "should not have an empty default case in a for+select loop. The loop will spin.")
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.ForStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckLhsRhsIdentical(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
op := node.(*ast.BinaryExpr)
|
||
switch op.Op {
|
||
case token.EQL, token.NEQ:
|
||
if basic, ok := pass.TypesInfo.TypeOf(op.X).Underlying().(*types.Basic); ok {
|
||
if kind := basic.Kind(); kind == types.Float32 || kind == types.Float64 {
|
||
// f == f and f != f might be used to check for NaN
|
||
return
|
||
}
|
||
}
|
||
case token.SUB, token.QUO, token.AND, token.REM, token.OR, token.XOR, token.AND_NOT,
|
||
token.LAND, token.LOR, token.LSS, token.GTR, token.LEQ, token.GEQ:
|
||
default:
|
||
// For some ops, such as + and *, it can make sense to
|
||
// have identical operands
|
||
return
|
||
}
|
||
|
||
if Render(pass, op.X) != Render(pass, op.Y) {
|
||
return
|
||
}
|
||
l1, ok1 := op.X.(*ast.BasicLit)
|
||
l2, ok2 := op.Y.(*ast.BasicLit)
|
||
if ok1 && ok2 && l1.Kind == token.INT && l2.Kind == l1.Kind && l1.Value == "0" && l2.Value == l1.Value && IsGenerated(pass, l1.Pos()) {
|
||
// cgo generates the following function call:
|
||
// _cgoCheckPointer(_cgoBase0, 0 == 0) – it uses 0 == 0
|
||
// instead of true in case the user shadowed the
|
||
// identifier. Ideally we'd restrict this exception to
|
||
// calls of _cgoCheckPointer, but it's not worth the
|
||
// hassle of keeping track of the stack. <lit> <op> <lit>
|
||
// are very rare to begin with, and we're mostly checking
|
||
// for them to catch typos such as 1 == 1 where the user
|
||
// meant to type i == 1. The odds of a false negative for
|
||
// 0 == 0 are slim.
|
||
return
|
||
}
|
||
ReportNodef(pass, op, "identical expressions on the left and right side of the '%s' operator", op.Op)
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.BinaryExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckScopedBreak(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
var body *ast.BlockStmt
|
||
switch node := node.(type) {
|
||
case *ast.ForStmt:
|
||
body = node.Body
|
||
case *ast.RangeStmt:
|
||
body = node.Body
|
||
default:
|
||
panic(fmt.Sprintf("unreachable: %T", node))
|
||
}
|
||
for _, stmt := range body.List {
|
||
var blocks [][]ast.Stmt
|
||
switch stmt := stmt.(type) {
|
||
case *ast.SwitchStmt:
|
||
for _, c := range stmt.Body.List {
|
||
blocks = append(blocks, c.(*ast.CaseClause).Body)
|
||
}
|
||
case *ast.SelectStmt:
|
||
for _, c := range stmt.Body.List {
|
||
blocks = append(blocks, c.(*ast.CommClause).Body)
|
||
}
|
||
default:
|
||
continue
|
||
}
|
||
|
||
for _, body := range blocks {
|
||
if len(body) == 0 {
|
||
continue
|
||
}
|
||
lasts := []ast.Stmt{body[len(body)-1]}
|
||
// TODO(dh): unfold all levels of nested block
|
||
// statements, not just a single level if statement
|
||
if ifs, ok := lasts[0].(*ast.IfStmt); ok {
|
||
if len(ifs.Body.List) == 0 {
|
||
continue
|
||
}
|
||
lasts[0] = ifs.Body.List[len(ifs.Body.List)-1]
|
||
|
||
if block, ok := ifs.Else.(*ast.BlockStmt); ok {
|
||
if len(block.List) != 0 {
|
||
lasts = append(lasts, block.List[len(block.List)-1])
|
||
}
|
||
}
|
||
}
|
||
for _, last := range lasts {
|
||
branch, ok := last.(*ast.BranchStmt)
|
||
if !ok || branch.Tok != token.BREAK || branch.Label != nil {
|
||
continue
|
||
}
|
||
ReportNodef(pass, branch, "ineffective break statement. Did you mean to break out of the outer loop?")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.ForStmt)(nil), (*ast.RangeStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckUnsafePrintf(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
var arg int
|
||
if IsCallToAnyAST(pass, call, "fmt.Printf", "fmt.Sprintf", "log.Printf") {
|
||
arg = Arg("fmt.Printf.format")
|
||
} else if IsCallToAnyAST(pass, call, "fmt.Fprintf") {
|
||
arg = Arg("fmt.Fprintf.format")
|
||
} else {
|
||
return
|
||
}
|
||
if len(call.Args) != arg+1 {
|
||
return
|
||
}
|
||
switch call.Args[arg].(type) {
|
||
case *ast.CallExpr, *ast.Ident:
|
||
default:
|
||
return
|
||
}
|
||
ReportNodef(pass, call.Args[arg],
|
||
"printf-style function with dynamic format string and no further arguments should use print-style function instead")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckEarlyDefer(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
block := node.(*ast.BlockStmt)
|
||
if len(block.List) < 2 {
|
||
return
|
||
}
|
||
for i, stmt := range block.List {
|
||
if i == len(block.List)-1 {
|
||
break
|
||
}
|
||
assign, ok := stmt.(*ast.AssignStmt)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if len(assign.Rhs) != 1 {
|
||
continue
|
||
}
|
||
if len(assign.Lhs) < 2 {
|
||
continue
|
||
}
|
||
if lhs, ok := assign.Lhs[len(assign.Lhs)-1].(*ast.Ident); ok && lhs.Name == "_" {
|
||
continue
|
||
}
|
||
call, ok := assign.Rhs[0].(*ast.CallExpr)
|
||
if !ok {
|
||
continue
|
||
}
|
||
sig, ok := pass.TypesInfo.TypeOf(call.Fun).(*types.Signature)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if sig.Results().Len() < 2 {
|
||
continue
|
||
}
|
||
last := sig.Results().At(sig.Results().Len() - 1)
|
||
// FIXME(dh): check that it's error from universe, not
|
||
// another type of the same name
|
||
if last.Type().String() != "error" {
|
||
continue
|
||
}
|
||
lhs, ok := assign.Lhs[0].(*ast.Ident)
|
||
if !ok {
|
||
continue
|
||
}
|
||
def, ok := block.List[i+1].(*ast.DeferStmt)
|
||
if !ok {
|
||
continue
|
||
}
|
||
sel, ok := def.Call.Fun.(*ast.SelectorExpr)
|
||
if !ok {
|
||
continue
|
||
}
|
||
ident, ok := selectorX(sel).(*ast.Ident)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if ident.Obj != lhs.Obj {
|
||
continue
|
||
}
|
||
if sel.Sel.Name != "Close" {
|
||
continue
|
||
}
|
||
ReportNodef(pass, def, "should check returned error before deferring %s", Render(pass, def.Call))
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.BlockStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func selectorX(sel *ast.SelectorExpr) ast.Node {
|
||
switch x := sel.X.(type) {
|
||
case *ast.SelectorExpr:
|
||
return selectorX(x)
|
||
default:
|
||
return x
|
||
}
|
||
}
|
||
|
||
func CheckEmptyCriticalSection(pass *analysis.Pass) (interface{}, error) {
|
||
// Initially it might seem like this check would be easier to
|
||
// implement in SSA. After all, we're only checking for two
|
||
// consecutive method calls. In reality, however, there may be any
|
||
// number of other instructions between the lock and unlock, while
|
||
// still constituting an empty critical section. For example,
|
||
// given `m.x().Lock(); m.x().Unlock()`, there will be a call to
|
||
// x(). In the AST-based approach, this has a tiny potential for a
|
||
// false positive (the second call to x might be doing work that
|
||
// is protected by the mutex). In an SSA-based approach, however,
|
||
// it would miss a lot of real bugs.
|
||
|
||
mutexParams := func(s ast.Stmt) (x ast.Expr, funcName string, ok bool) {
|
||
expr, ok := s.(*ast.ExprStmt)
|
||
if !ok {
|
||
return nil, "", false
|
||
}
|
||
call, ok := expr.X.(*ast.CallExpr)
|
||
if !ok {
|
||
return nil, "", false
|
||
}
|
||
sel, ok := call.Fun.(*ast.SelectorExpr)
|
||
if !ok {
|
||
return nil, "", false
|
||
}
|
||
|
||
fn, ok := pass.TypesInfo.ObjectOf(sel.Sel).(*types.Func)
|
||
if !ok {
|
||
return nil, "", false
|
||
}
|
||
sig := fn.Type().(*types.Signature)
|
||
if sig.Params().Len() != 0 || sig.Results().Len() != 0 {
|
||
return nil, "", false
|
||
}
|
||
|
||
return sel.X, fn.Name(), true
|
||
}
|
||
|
||
fn := func(node ast.Node) {
|
||
block := node.(*ast.BlockStmt)
|
||
if len(block.List) < 2 {
|
||
return
|
||
}
|
||
for i := range block.List[:len(block.List)-1] {
|
||
sel1, method1, ok1 := mutexParams(block.List[i])
|
||
sel2, method2, ok2 := mutexParams(block.List[i+1])
|
||
|
||
if !ok1 || !ok2 || Render(pass, sel1) != Render(pass, sel2) {
|
||
continue
|
||
}
|
||
if (method1 == "Lock" && method2 == "Unlock") ||
|
||
(method1 == "RLock" && method2 == "RUnlock") {
|
||
ReportNodef(pass, block.List[i+1], "empty critical section")
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.BlockStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
// cgo produces code like fn(&*_Cvar_kSomeCallbacks) which we don't
|
||
// want to flag.
|
||
var cgoIdent = regexp.MustCompile(`^_C(func|var)_.+$`)
|
||
|
||
func CheckIneffectiveCopy(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
if unary, ok := node.(*ast.UnaryExpr); ok {
|
||
if star, ok := unary.X.(*ast.StarExpr); ok && unary.Op == token.AND {
|
||
ident, ok := star.X.(*ast.Ident)
|
||
if !ok || !cgoIdent.MatchString(ident.Name) {
|
||
ReportNodef(pass, unary, "&*x will be simplified to x. It will not copy x.")
|
||
}
|
||
}
|
||
}
|
||
|
||
if star, ok := node.(*ast.StarExpr); ok {
|
||
if unary, ok := star.X.(*ast.UnaryExpr); ok && unary.Op == token.AND {
|
||
ReportNodef(pass, star, "*&x will be simplified to x. It will not copy x.")
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.UnaryExpr)(nil), (*ast.StarExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckDiffSizeComparison(pass *analysis.Pass) (interface{}, error) {
|
||
ranges := pass.ResultOf[valueRangesAnalyzer].(map[*ssa.Function]vrp.Ranges)
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, b := range ssafn.Blocks {
|
||
for _, ins := range b.Instrs {
|
||
binop, ok := ins.(*ssa.BinOp)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if binop.Op != token.EQL && binop.Op != token.NEQ {
|
||
continue
|
||
}
|
||
_, ok1 := binop.X.(*ssa.Slice)
|
||
_, ok2 := binop.Y.(*ssa.Slice)
|
||
if !ok1 && !ok2 {
|
||
continue
|
||
}
|
||
r := ranges[ssafn]
|
||
r1, ok1 := r.Get(binop.X).(vrp.StringInterval)
|
||
r2, ok2 := r.Get(binop.Y).(vrp.StringInterval)
|
||
if !ok1 || !ok2 {
|
||
continue
|
||
}
|
||
if r1.Length.Intersection(r2.Length).Empty() {
|
||
pass.Reportf(binop.Pos(), "comparing strings of different sizes for equality will always return false")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckCanonicalHeaderKey(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node, push bool) bool {
|
||
if !push {
|
||
return false
|
||
}
|
||
assign, ok := node.(*ast.AssignStmt)
|
||
if ok {
|
||
// TODO(dh): This risks missing some Header reads, for
|
||
// example in `h1["foo"] = h2["foo"]` – these edge
|
||
// cases are probably rare enough to ignore for now.
|
||
for _, expr := range assign.Lhs {
|
||
op, ok := expr.(*ast.IndexExpr)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if IsOfType(pass, op.X, "net/http.Header") {
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
op, ok := node.(*ast.IndexExpr)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if !IsOfType(pass, op.X, "net/http.Header") {
|
||
return true
|
||
}
|
||
s, ok := ExprToString(pass, op.Index)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if s == http.CanonicalHeaderKey(s) {
|
||
return true
|
||
}
|
||
ReportNodef(pass, op, "keys in http.Header are canonicalized, %q is not canonical; fix the constant or use http.CanonicalHeaderKey", s)
|
||
return true
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Nodes([]ast.Node{(*ast.AssignStmt)(nil), (*ast.IndexExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckBenchmarkN(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
assign := node.(*ast.AssignStmt)
|
||
if len(assign.Lhs) != 1 || len(assign.Rhs) != 1 {
|
||
return
|
||
}
|
||
sel, ok := assign.Lhs[0].(*ast.SelectorExpr)
|
||
if !ok {
|
||
return
|
||
}
|
||
if sel.Sel.Name != "N" {
|
||
return
|
||
}
|
||
if !IsOfType(pass, sel.X, "*testing.B") {
|
||
return
|
||
}
|
||
ReportNodef(pass, assign, "should not assign to %s", Render(pass, sel))
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.AssignStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckUnreadVariableValues(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
if IsExample(ssafn) {
|
||
continue
|
||
}
|
||
node := ssafn.Syntax()
|
||
if node == nil {
|
||
continue
|
||
}
|
||
if gen, ok := Generator(pass, node.Pos()); ok && gen == facts.Goyacc {
|
||
// Don't flag unused values in code generated by goyacc.
|
||
// There may be hundreds of those due to the way the state
|
||
// machine is constructed.
|
||
continue
|
||
}
|
||
|
||
switchTags := map[ssa.Value]struct{}{}
|
||
ast.Inspect(node, func(node ast.Node) bool {
|
||
s, ok := node.(*ast.SwitchStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
v, _ := ssafn.ValueForExpr(s.Tag)
|
||
switchTags[v] = struct{}{}
|
||
return true
|
||
})
|
||
|
||
hasUse := func(v ssa.Value) bool {
|
||
if _, ok := switchTags[v]; ok {
|
||
return true
|
||
}
|
||
refs := v.Referrers()
|
||
if refs == nil {
|
||
// TODO investigate why refs can be nil
|
||
return true
|
||
}
|
||
return len(FilterDebug(*refs)) > 0
|
||
}
|
||
|
||
ast.Inspect(node, func(node ast.Node) bool {
|
||
assign, ok := node.(*ast.AssignStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if len(assign.Lhs) > 1 && len(assign.Rhs) == 1 {
|
||
// Either a function call with multiple return values,
|
||
// or a comma-ok assignment
|
||
|
||
val, _ := ssafn.ValueForExpr(assign.Rhs[0])
|
||
if val == nil {
|
||
return true
|
||
}
|
||
refs := val.Referrers()
|
||
if refs == nil {
|
||
return true
|
||
}
|
||
for _, ref := range *refs {
|
||
ex, ok := ref.(*ssa.Extract)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if !hasUse(ex) {
|
||
lhs := assign.Lhs[ex.Index]
|
||
if ident, ok := lhs.(*ast.Ident); !ok || ok && ident.Name == "_" {
|
||
continue
|
||
}
|
||
ReportNodef(pass, lhs, "this value of %s is never used", lhs)
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
for i, lhs := range assign.Lhs {
|
||
rhs := assign.Rhs[i]
|
||
if ident, ok := lhs.(*ast.Ident); !ok || ok && ident.Name == "_" {
|
||
continue
|
||
}
|
||
val, _ := ssafn.ValueForExpr(rhs)
|
||
if val == nil {
|
||
continue
|
||
}
|
||
|
||
if !hasUse(val) {
|
||
ReportNodef(pass, lhs, "this value of %s is never used", lhs)
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckPredeterminedBooleanExprs(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
ssabinop, ok := ins.(*ssa.BinOp)
|
||
if !ok {
|
||
continue
|
||
}
|
||
switch ssabinop.Op {
|
||
case token.GTR, token.LSS, token.EQL, token.NEQ, token.LEQ, token.GEQ:
|
||
default:
|
||
continue
|
||
}
|
||
|
||
xs, ok1 := consts(ssabinop.X, nil, nil)
|
||
ys, ok2 := consts(ssabinop.Y, nil, nil)
|
||
if !ok1 || !ok2 || len(xs) == 0 || len(ys) == 0 {
|
||
continue
|
||
}
|
||
|
||
trues := 0
|
||
for _, x := range xs {
|
||
for _, y := range ys {
|
||
if x.Value == nil {
|
||
if y.Value == nil {
|
||
trues++
|
||
}
|
||
continue
|
||
}
|
||
if constant.Compare(x.Value, ssabinop.Op, y.Value) {
|
||
trues++
|
||
}
|
||
}
|
||
}
|
||
b := trues != 0
|
||
if trues == 0 || trues == len(xs)*len(ys) {
|
||
pass.Reportf(ssabinop.Pos(), "binary expression is always %t for all possible values (%s %s %s)",
|
||
b, xs, ssabinop.Op, ys)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckNilMaps(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
mu, ok := ins.(*ssa.MapUpdate)
|
||
if !ok {
|
||
continue
|
||
}
|
||
c, ok := mu.Map.(*ssa.Const)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if c.Value != nil {
|
||
continue
|
||
}
|
||
pass.Reportf(mu.Pos(), "assignment to nil map")
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckExtremeComparison(pass *analysis.Pass) (interface{}, error) {
|
||
isobj := func(expr ast.Expr, name string) bool {
|
||
sel, ok := expr.(*ast.SelectorExpr)
|
||
if !ok {
|
||
return false
|
||
}
|
||
return IsObject(pass.TypesInfo.ObjectOf(sel.Sel), name)
|
||
}
|
||
|
||
fn := func(node ast.Node) {
|
||
expr := node.(*ast.BinaryExpr)
|
||
tx := pass.TypesInfo.TypeOf(expr.X)
|
||
basic, ok := tx.Underlying().(*types.Basic)
|
||
if !ok {
|
||
return
|
||
}
|
||
|
||
var max string
|
||
var min string
|
||
|
||
switch basic.Kind() {
|
||
case types.Uint8:
|
||
max = "math.MaxUint8"
|
||
case types.Uint16:
|
||
max = "math.MaxUint16"
|
||
case types.Uint32:
|
||
max = "math.MaxUint32"
|
||
case types.Uint64:
|
||
max = "math.MaxUint64"
|
||
case types.Uint:
|
||
max = "math.MaxUint64"
|
||
|
||
case types.Int8:
|
||
min = "math.MinInt8"
|
||
max = "math.MaxInt8"
|
||
case types.Int16:
|
||
min = "math.MinInt16"
|
||
max = "math.MaxInt16"
|
||
case types.Int32:
|
||
min = "math.MinInt32"
|
||
max = "math.MaxInt32"
|
||
case types.Int64:
|
||
min = "math.MinInt64"
|
||
max = "math.MaxInt64"
|
||
case types.Int:
|
||
min = "math.MinInt64"
|
||
max = "math.MaxInt64"
|
||
}
|
||
|
||
if (expr.Op == token.GTR || expr.Op == token.GEQ) && isobj(expr.Y, max) ||
|
||
(expr.Op == token.LSS || expr.Op == token.LEQ) && isobj(expr.X, max) {
|
||
ReportNodef(pass, expr, "no value of type %s is greater than %s", basic, max)
|
||
}
|
||
if expr.Op == token.LEQ && isobj(expr.Y, max) ||
|
||
expr.Op == token.GEQ && isobj(expr.X, max) {
|
||
ReportNodef(pass, expr, "every value of type %s is <= %s", basic, max)
|
||
}
|
||
|
||
if (basic.Info() & types.IsUnsigned) != 0 {
|
||
if (expr.Op == token.LSS || expr.Op == token.LEQ) && IsIntLiteral(expr.Y, "0") ||
|
||
(expr.Op == token.GTR || expr.Op == token.GEQ) && IsIntLiteral(expr.X, "0") {
|
||
ReportNodef(pass, expr, "no value of type %s is less than 0", basic)
|
||
}
|
||
if expr.Op == token.GEQ && IsIntLiteral(expr.Y, "0") ||
|
||
expr.Op == token.LEQ && IsIntLiteral(expr.X, "0") {
|
||
ReportNodef(pass, expr, "every value of type %s is >= 0", basic)
|
||
}
|
||
} else {
|
||
if (expr.Op == token.LSS || expr.Op == token.LEQ) && isobj(expr.Y, min) ||
|
||
(expr.Op == token.GTR || expr.Op == token.GEQ) && isobj(expr.X, min) {
|
||
ReportNodef(pass, expr, "no value of type %s is less than %s", basic, min)
|
||
}
|
||
if expr.Op == token.GEQ && isobj(expr.Y, min) ||
|
||
expr.Op == token.LEQ && isobj(expr.X, min) {
|
||
ReportNodef(pass, expr, "every value of type %s is >= %s", basic, min)
|
||
}
|
||
}
|
||
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.BinaryExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func consts(val ssa.Value, out []*ssa.Const, visitedPhis map[string]bool) ([]*ssa.Const, bool) {
|
||
if visitedPhis == nil {
|
||
visitedPhis = map[string]bool{}
|
||
}
|
||
var ok bool
|
||
switch val := val.(type) {
|
||
case *ssa.Phi:
|
||
if visitedPhis[val.Name()] {
|
||
break
|
||
}
|
||
visitedPhis[val.Name()] = true
|
||
vals := val.Operands(nil)
|
||
for _, phival := range vals {
|
||
out, ok = consts(*phival, out, visitedPhis)
|
||
if !ok {
|
||
return nil, false
|
||
}
|
||
}
|
||
case *ssa.Const:
|
||
out = append(out, val)
|
||
case *ssa.Convert:
|
||
out, ok = consts(val.X, out, visitedPhis)
|
||
if !ok {
|
||
return nil, false
|
||
}
|
||
default:
|
||
return nil, false
|
||
}
|
||
if len(out) < 2 {
|
||
return out, true
|
||
}
|
||
uniq := []*ssa.Const{out[0]}
|
||
for _, val := range out[1:] {
|
||
if val.Value == uniq[len(uniq)-1].Value {
|
||
continue
|
||
}
|
||
uniq = append(uniq, val)
|
||
}
|
||
return uniq, true
|
||
}
|
||
|
||
func CheckLoopCondition(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
fn := func(node ast.Node) bool {
|
||
loop, ok := node.(*ast.ForStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if loop.Init == nil || loop.Cond == nil || loop.Post == nil {
|
||
return true
|
||
}
|
||
init, ok := loop.Init.(*ast.AssignStmt)
|
||
if !ok || len(init.Lhs) != 1 || len(init.Rhs) != 1 {
|
||
return true
|
||
}
|
||
cond, ok := loop.Cond.(*ast.BinaryExpr)
|
||
if !ok {
|
||
return true
|
||
}
|
||
x, ok := cond.X.(*ast.Ident)
|
||
if !ok {
|
||
return true
|
||
}
|
||
lhs, ok := init.Lhs[0].(*ast.Ident)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if x.Obj != lhs.Obj {
|
||
return true
|
||
}
|
||
if _, ok := loop.Post.(*ast.IncDecStmt); !ok {
|
||
return true
|
||
}
|
||
|
||
v, isAddr := ssafn.ValueForExpr(cond.X)
|
||
if v == nil || isAddr {
|
||
return true
|
||
}
|
||
switch v := v.(type) {
|
||
case *ssa.Phi:
|
||
ops := v.Operands(nil)
|
||
if len(ops) != 2 {
|
||
return true
|
||
}
|
||
_, ok := (*ops[0]).(*ssa.Const)
|
||
if !ok {
|
||
return true
|
||
}
|
||
sigma, ok := (*ops[1]).(*ssa.Sigma)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if sigma.X != v {
|
||
return true
|
||
}
|
||
case *ssa.UnOp:
|
||
return true
|
||
}
|
||
ReportNodef(pass, cond, "variable in loop condition never changes")
|
||
|
||
return true
|
||
}
|
||
Inspect(ssafn.Syntax(), fn)
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckArgOverwritten(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
fn := func(node ast.Node) bool {
|
||
var typ *ast.FuncType
|
||
var body *ast.BlockStmt
|
||
switch fn := node.(type) {
|
||
case *ast.FuncDecl:
|
||
typ = fn.Type
|
||
body = fn.Body
|
||
case *ast.FuncLit:
|
||
typ = fn.Type
|
||
body = fn.Body
|
||
}
|
||
if body == nil {
|
||
return true
|
||
}
|
||
if len(typ.Params.List) == 0 {
|
||
return true
|
||
}
|
||
for _, field := range typ.Params.List {
|
||
for _, arg := range field.Names {
|
||
obj := pass.TypesInfo.ObjectOf(arg)
|
||
var ssaobj *ssa.Parameter
|
||
for _, param := range ssafn.Params {
|
||
if param.Object() == obj {
|
||
ssaobj = param
|
||
break
|
||
}
|
||
}
|
||
if ssaobj == nil {
|
||
continue
|
||
}
|
||
refs := ssaobj.Referrers()
|
||
if refs == nil {
|
||
continue
|
||
}
|
||
if len(FilterDebug(*refs)) != 0 {
|
||
continue
|
||
}
|
||
|
||
assigned := false
|
||
ast.Inspect(body, func(node ast.Node) bool {
|
||
assign, ok := node.(*ast.AssignStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
for _, lhs := range assign.Lhs {
|
||
ident, ok := lhs.(*ast.Ident)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if pass.TypesInfo.ObjectOf(ident) == obj {
|
||
assigned = true
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
if assigned {
|
||
ReportNodef(pass, arg, "argument %s is overwritten before first use", arg)
|
||
}
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
Inspect(ssafn.Syntax(), fn)
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckIneffectiveLoop(pass *analysis.Pass) (interface{}, error) {
|
||
// This check detects some, but not all unconditional loop exits.
|
||
// We give up in the following cases:
|
||
//
|
||
// - a goto anywhere in the loop. The goto might skip over our
|
||
// return, and we don't check that it doesn't.
|
||
//
|
||
// - any nested, unlabelled continue, even if it is in another
|
||
// loop or closure.
|
||
fn := func(node ast.Node) {
|
||
var body *ast.BlockStmt
|
||
switch fn := node.(type) {
|
||
case *ast.FuncDecl:
|
||
body = fn.Body
|
||
case *ast.FuncLit:
|
||
body = fn.Body
|
||
default:
|
||
panic(fmt.Sprintf("unreachable: %T", node))
|
||
}
|
||
if body == nil {
|
||
return
|
||
}
|
||
labels := map[*ast.Object]ast.Stmt{}
|
||
ast.Inspect(body, func(node ast.Node) bool {
|
||
label, ok := node.(*ast.LabeledStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
labels[label.Label.Obj] = label.Stmt
|
||
return true
|
||
})
|
||
|
||
ast.Inspect(body, func(node ast.Node) bool {
|
||
var loop ast.Node
|
||
var body *ast.BlockStmt
|
||
switch node := node.(type) {
|
||
case *ast.ForStmt:
|
||
body = node.Body
|
||
loop = node
|
||
case *ast.RangeStmt:
|
||
typ := pass.TypesInfo.TypeOf(node.X)
|
||
if _, ok := typ.Underlying().(*types.Map); ok {
|
||
// looping once over a map is a valid pattern for
|
||
// getting an arbitrary element.
|
||
return true
|
||
}
|
||
body = node.Body
|
||
loop = node
|
||
default:
|
||
return true
|
||
}
|
||
if len(body.List) < 2 {
|
||
// avoid flagging the somewhat common pattern of using
|
||
// a range loop to get the first element in a slice,
|
||
// or the first rune in a string.
|
||
return true
|
||
}
|
||
var unconditionalExit ast.Node
|
||
hasBranching := false
|
||
for _, stmt := range body.List {
|
||
switch stmt := stmt.(type) {
|
||
case *ast.BranchStmt:
|
||
switch stmt.Tok {
|
||
case token.BREAK:
|
||
if stmt.Label == nil || labels[stmt.Label.Obj] == loop {
|
||
unconditionalExit = stmt
|
||
}
|
||
case token.CONTINUE:
|
||
if stmt.Label == nil || labels[stmt.Label.Obj] == loop {
|
||
unconditionalExit = nil
|
||
return false
|
||
}
|
||
}
|
||
case *ast.ReturnStmt:
|
||
unconditionalExit = stmt
|
||
case *ast.IfStmt, *ast.ForStmt, *ast.RangeStmt, *ast.SwitchStmt, *ast.SelectStmt:
|
||
hasBranching = true
|
||
}
|
||
}
|
||
if unconditionalExit == nil || !hasBranching {
|
||
return false
|
||
}
|
||
ast.Inspect(body, func(node ast.Node) bool {
|
||
if branch, ok := node.(*ast.BranchStmt); ok {
|
||
|
||
switch branch.Tok {
|
||
case token.GOTO:
|
||
unconditionalExit = nil
|
||
return false
|
||
case token.CONTINUE:
|
||
if branch.Label != nil && labels[branch.Label.Obj] != loop {
|
||
return true
|
||
}
|
||
unconditionalExit = nil
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
if unconditionalExit != nil {
|
||
ReportNodef(pass, unconditionalExit, "the surrounding loop is unconditionally terminated")
|
||
}
|
||
return true
|
||
})
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.FuncDecl)(nil), (*ast.FuncLit)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckNilContext(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
if len(call.Args) == 0 {
|
||
return
|
||
}
|
||
if typ, ok := pass.TypesInfo.TypeOf(call.Args[0]).(*types.Basic); !ok || typ.Kind() != types.UntypedNil {
|
||
return
|
||
}
|
||
sig, ok := pass.TypesInfo.TypeOf(call.Fun).(*types.Signature)
|
||
if !ok {
|
||
return
|
||
}
|
||
if sig.Params().Len() == 0 {
|
||
return
|
||
}
|
||
if !IsType(sig.Params().At(0).Type(), "context.Context") {
|
||
return
|
||
}
|
||
ReportNodef(pass, call.Args[0],
|
||
"do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckSeeker(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
sel, ok := call.Fun.(*ast.SelectorExpr)
|
||
if !ok {
|
||
return
|
||
}
|
||
if sel.Sel.Name != "Seek" {
|
||
return
|
||
}
|
||
if len(call.Args) != 2 {
|
||
return
|
||
}
|
||
arg0, ok := call.Args[Arg("(io.Seeker).Seek.offset")].(*ast.SelectorExpr)
|
||
if !ok {
|
||
return
|
||
}
|
||
switch arg0.Sel.Name {
|
||
case "SeekStart", "SeekCurrent", "SeekEnd":
|
||
default:
|
||
return
|
||
}
|
||
pkg, ok := arg0.X.(*ast.Ident)
|
||
if !ok {
|
||
return
|
||
}
|
||
if pkg.Name != "io" {
|
||
return
|
||
}
|
||
ReportNodef(pass, call, "the first argument of io.Seeker is the offset, but an io.Seek* constant is being used instead")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckIneffectiveAppend(pass *analysis.Pass) (interface{}, error) {
|
||
isAppend := func(ins ssa.Value) bool {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
return false
|
||
}
|
||
if call.Call.IsInvoke() {
|
||
return false
|
||
}
|
||
if builtin, ok := call.Call.Value.(*ssa.Builtin); !ok || builtin.Name() != "append" {
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
val, ok := ins.(ssa.Value)
|
||
if !ok || !isAppend(val) {
|
||
continue
|
||
}
|
||
|
||
isUsed := false
|
||
visited := map[ssa.Instruction]bool{}
|
||
var walkRefs func(refs []ssa.Instruction)
|
||
walkRefs = func(refs []ssa.Instruction) {
|
||
loop:
|
||
for _, ref := range refs {
|
||
if visited[ref] {
|
||
continue
|
||
}
|
||
visited[ref] = true
|
||
if _, ok := ref.(*ssa.DebugRef); ok {
|
||
continue
|
||
}
|
||
switch ref := ref.(type) {
|
||
case *ssa.Phi:
|
||
walkRefs(*ref.Referrers())
|
||
case *ssa.Sigma:
|
||
walkRefs(*ref.Referrers())
|
||
case ssa.Value:
|
||
if !isAppend(ref) {
|
||
isUsed = true
|
||
} else {
|
||
walkRefs(*ref.Referrers())
|
||
}
|
||
case ssa.Instruction:
|
||
isUsed = true
|
||
break loop
|
||
}
|
||
}
|
||
}
|
||
refs := val.Referrers()
|
||
if refs == nil {
|
||
continue
|
||
}
|
||
walkRefs(*refs)
|
||
if !isUsed {
|
||
pass.Reportf(ins.Pos(), "this result of append is never used, except maybe in other appends")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckConcurrentTesting(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
gostmt, ok := ins.(*ssa.Go)
|
||
if !ok {
|
||
continue
|
||
}
|
||
var fn *ssa.Function
|
||
switch val := gostmt.Call.Value.(type) {
|
||
case *ssa.Function:
|
||
fn = val
|
||
case *ssa.MakeClosure:
|
||
fn = val.Fn.(*ssa.Function)
|
||
default:
|
||
continue
|
||
}
|
||
if fn.Blocks == nil {
|
||
continue
|
||
}
|
||
for _, block := range fn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if call.Call.IsInvoke() {
|
||
continue
|
||
}
|
||
callee := call.Call.StaticCallee()
|
||
if callee == nil {
|
||
continue
|
||
}
|
||
recv := callee.Signature.Recv()
|
||
if recv == nil {
|
||
continue
|
||
}
|
||
if !IsType(recv.Type(), "*testing.common") {
|
||
continue
|
||
}
|
||
fn, ok := call.Call.StaticCallee().Object().(*types.Func)
|
||
if !ok {
|
||
continue
|
||
}
|
||
name := fn.Name()
|
||
switch name {
|
||
case "FailNow", "Fatal", "Fatalf", "SkipNow", "Skip", "Skipf":
|
||
default:
|
||
continue
|
||
}
|
||
pass.Reportf(gostmt.Pos(), "the goroutine calls T.%s, which must be called in the same goroutine as the test", name)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func eachCall(ssafn *ssa.Function, fn func(caller *ssa.Function, site ssa.CallInstruction, callee *ssa.Function)) {
|
||
for _, b := range ssafn.Blocks {
|
||
for _, instr := range b.Instrs {
|
||
if site, ok := instr.(ssa.CallInstruction); ok {
|
||
if g := site.Common().StaticCallee(); g != nil {
|
||
fn(ssafn, site, g)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
func CheckCyclicFinalizer(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(caller *ssa.Function, site ssa.CallInstruction, callee *ssa.Function) {
|
||
if callee.RelString(nil) != "runtime.SetFinalizer" {
|
||
return
|
||
}
|
||
arg0 := site.Common().Args[Arg("runtime.SetFinalizer.obj")]
|
||
if iface, ok := arg0.(*ssa.MakeInterface); ok {
|
||
arg0 = iface.X
|
||
}
|
||
unop, ok := arg0.(*ssa.UnOp)
|
||
if !ok {
|
||
return
|
||
}
|
||
v, ok := unop.X.(*ssa.Alloc)
|
||
if !ok {
|
||
return
|
||
}
|
||
arg1 := site.Common().Args[Arg("runtime.SetFinalizer.finalizer")]
|
||
if iface, ok := arg1.(*ssa.MakeInterface); ok {
|
||
arg1 = iface.X
|
||
}
|
||
mc, ok := arg1.(*ssa.MakeClosure)
|
||
if !ok {
|
||
return
|
||
}
|
||
for _, b := range mc.Bindings {
|
||
if b == v {
|
||
pos := lint.DisplayPosition(pass.Fset, mc.Fn.Pos())
|
||
pass.Reportf(site.Pos(), "the finalizer closes over the object, preventing the finalizer from ever running (at %s)", pos)
|
||
}
|
||
}
|
||
}
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
eachCall(ssafn, fn)
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
/*
|
||
func CheckSliceOutOfBounds(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
ia, ok := ins.(*ssa.IndexAddr)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if _, ok := ia.X.Type().Underlying().(*types.Slice); !ok {
|
||
continue
|
||
}
|
||
sr, ok1 := c.funcDescs.Get(ssafn).Ranges[ia.X].(vrp.SliceInterval)
|
||
idxr, ok2 := c.funcDescs.Get(ssafn).Ranges[ia.Index].(vrp.IntInterval)
|
||
if !ok1 || !ok2 || !sr.IsKnown() || !idxr.IsKnown() || sr.Length.Empty() || idxr.Empty() {
|
||
continue
|
||
}
|
||
if idxr.Lower.Cmp(sr.Length.Upper) >= 0 {
|
||
ReportNodef(pass, ia, "index out of bounds")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
*/
|
||
|
||
func CheckDeferLock(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
instrs := FilterDebug(block.Instrs)
|
||
if len(instrs) < 2 {
|
||
continue
|
||
}
|
||
for i, ins := range instrs[:len(instrs)-1] {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if !IsCallTo(call.Common(), "(*sync.Mutex).Lock") && !IsCallTo(call.Common(), "(*sync.RWMutex).RLock") {
|
||
continue
|
||
}
|
||
nins, ok := instrs[i+1].(*ssa.Defer)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if !IsCallTo(&nins.Call, "(*sync.Mutex).Lock") && !IsCallTo(&nins.Call, "(*sync.RWMutex).RLock") {
|
||
continue
|
||
}
|
||
if call.Common().Args[0] != nins.Call.Args[0] {
|
||
continue
|
||
}
|
||
name := shortCallName(call.Common())
|
||
alt := ""
|
||
switch name {
|
||
case "Lock":
|
||
alt = "Unlock"
|
||
case "RLock":
|
||
alt = "RUnlock"
|
||
}
|
||
pass.Reportf(nins.Pos(), "deferring %s right after having locked already; did you mean to defer %s?", name, alt)
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckNaNComparison(pass *analysis.Pass) (interface{}, error) {
|
||
isNaN := func(v ssa.Value) bool {
|
||
call, ok := v.(*ssa.Call)
|
||
if !ok {
|
||
return false
|
||
}
|
||
return IsCallTo(call.Common(), "math.NaN")
|
||
}
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
ins, ok := ins.(*ssa.BinOp)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if isNaN(ins.X) || isNaN(ins.Y) {
|
||
pass.Reportf(ins.Pos(), "no value is equal to NaN, not even NaN itself")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckInfiniteRecursion(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
eachCall(ssafn, func(caller *ssa.Function, site ssa.CallInstruction, callee *ssa.Function) {
|
||
if callee != ssafn {
|
||
return
|
||
}
|
||
if _, ok := site.(*ssa.Go); ok {
|
||
// Recursively spawning goroutines doesn't consume
|
||
// stack space infinitely, so don't flag it.
|
||
return
|
||
}
|
||
|
||
block := site.Block()
|
||
canReturn := false
|
||
for _, b := range ssafn.Blocks {
|
||
if block.Dominates(b) {
|
||
continue
|
||
}
|
||
if len(b.Instrs) == 0 {
|
||
continue
|
||
}
|
||
if _, ok := b.Instrs[len(b.Instrs)-1].(*ssa.Return); ok {
|
||
canReturn = true
|
||
break
|
||
}
|
||
}
|
||
if canReturn {
|
||
return
|
||
}
|
||
pass.Reportf(site.Pos(), "infinite recursive call")
|
||
})
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func objectName(obj types.Object) string {
|
||
if obj == nil {
|
||
return "<nil>"
|
||
}
|
||
var name string
|
||
if obj.Pkg() != nil && obj.Pkg().Scope().Lookup(obj.Name()) == obj {
|
||
s := obj.Pkg().Path()
|
||
if s != "" {
|
||
name += s + "."
|
||
}
|
||
}
|
||
name += obj.Name()
|
||
return name
|
||
}
|
||
|
||
func isName(pass *analysis.Pass, expr ast.Expr, name string) bool {
|
||
var obj types.Object
|
||
switch expr := expr.(type) {
|
||
case *ast.Ident:
|
||
obj = pass.TypesInfo.ObjectOf(expr)
|
||
case *ast.SelectorExpr:
|
||
obj = pass.TypesInfo.ObjectOf(expr.Sel)
|
||
}
|
||
return objectName(obj) == name
|
||
}
|
||
|
||
func CheckLeakyTimeTick(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
if IsInMain(pass, ssafn) || IsInTest(pass, ssafn) {
|
||
continue
|
||
}
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok || !IsCallTo(call.Common(), "time.Tick") {
|
||
continue
|
||
}
|
||
if !functions.Terminates(call.Parent()) {
|
||
continue
|
||
}
|
||
pass.Reportf(call.Pos(), "using time.Tick leaks the underlying ticker, consider using it only in endless functions, tests and the main package, and use time.NewTicker here")
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckDoubleNegation(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
unary1 := node.(*ast.UnaryExpr)
|
||
unary2, ok := unary1.X.(*ast.UnaryExpr)
|
||
if !ok {
|
||
return
|
||
}
|
||
if unary1.Op != token.NOT || unary2.Op != token.NOT {
|
||
return
|
||
}
|
||
ReportNodef(pass, unary1, "negating a boolean twice has no effect; is this a typo?")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.UnaryExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func hasSideEffects(node ast.Node) bool {
|
||
dynamic := false
|
||
ast.Inspect(node, func(node ast.Node) bool {
|
||
switch node := node.(type) {
|
||
case *ast.CallExpr:
|
||
dynamic = true
|
||
return false
|
||
case *ast.UnaryExpr:
|
||
if node.Op == token.ARROW {
|
||
dynamic = true
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
return dynamic
|
||
}
|
||
|
||
func CheckRepeatedIfElse(pass *analysis.Pass) (interface{}, error) {
|
||
seen := map[ast.Node]bool{}
|
||
|
||
var collectConds func(ifstmt *ast.IfStmt, inits []ast.Stmt, conds []ast.Expr) ([]ast.Stmt, []ast.Expr)
|
||
collectConds = func(ifstmt *ast.IfStmt, inits []ast.Stmt, conds []ast.Expr) ([]ast.Stmt, []ast.Expr) {
|
||
seen[ifstmt] = true
|
||
if ifstmt.Init != nil {
|
||
inits = append(inits, ifstmt.Init)
|
||
}
|
||
conds = append(conds, ifstmt.Cond)
|
||
if elsestmt, ok := ifstmt.Else.(*ast.IfStmt); ok {
|
||
return collectConds(elsestmt, inits, conds)
|
||
}
|
||
return inits, conds
|
||
}
|
||
fn := func(node ast.Node) {
|
||
ifstmt := node.(*ast.IfStmt)
|
||
if seen[ifstmt] {
|
||
return
|
||
}
|
||
inits, conds := collectConds(ifstmt, nil, nil)
|
||
if len(inits) > 0 {
|
||
return
|
||
}
|
||
for _, cond := range conds {
|
||
if hasSideEffects(cond) {
|
||
return
|
||
}
|
||
}
|
||
counts := map[string]int{}
|
||
for _, cond := range conds {
|
||
s := Render(pass, cond)
|
||
counts[s]++
|
||
if counts[s] == 2 {
|
||
ReportNodef(pass, cond, "this condition occurs multiple times in this if/else if chain")
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.IfStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckSillyBitwiseOps(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
ins, ok := ins.(*ssa.BinOp)
|
||
if !ok {
|
||
continue
|
||
}
|
||
|
||
if c, ok := ins.Y.(*ssa.Const); !ok || c.Value == nil || c.Value.Kind() != constant.Int || c.Uint64() != 0 {
|
||
continue
|
||
}
|
||
switch ins.Op {
|
||
case token.AND, token.OR, token.XOR:
|
||
default:
|
||
// we do not flag shifts because too often, x<<0 is part
|
||
// of a pattern, x<<0, x<<8, x<<16, ...
|
||
continue
|
||
}
|
||
path, _ := astutil.PathEnclosingInterval(File(pass, ins), ins.Pos(), ins.Pos())
|
||
if len(path) == 0 {
|
||
continue
|
||
}
|
||
if node, ok := path[0].(*ast.BinaryExpr); !ok || !IsZero(node.Y) {
|
||
continue
|
||
}
|
||
|
||
switch ins.Op {
|
||
case token.AND:
|
||
pass.Reportf(ins.Pos(), "x & 0 always equals 0")
|
||
case token.OR, token.XOR:
|
||
pass.Reportf(ins.Pos(), "x %s 0 always equals x", ins.Op)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckNonOctalFileMode(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
call := node.(*ast.CallExpr)
|
||
sig, ok := pass.TypesInfo.TypeOf(call.Fun).(*types.Signature)
|
||
if !ok {
|
||
return
|
||
}
|
||
n := sig.Params().Len()
|
||
var args []int
|
||
for i := 0; i < n; i++ {
|
||
typ := sig.Params().At(i).Type()
|
||
if IsType(typ, "os.FileMode") {
|
||
args = append(args, i)
|
||
}
|
||
}
|
||
for _, i := range args {
|
||
lit, ok := call.Args[i].(*ast.BasicLit)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if len(lit.Value) == 3 &&
|
||
lit.Value[0] != '0' &&
|
||
lit.Value[0] >= '0' && lit.Value[0] <= '7' &&
|
||
lit.Value[1] >= '0' && lit.Value[1] <= '7' &&
|
||
lit.Value[2] >= '0' && lit.Value[2] <= '7' {
|
||
|
||
v, err := strconv.ParseInt(lit.Value, 10, 64)
|
||
if err != nil {
|
||
continue
|
||
}
|
||
ReportNodef(pass, call.Args[i], "file mode '%s' evaluates to %#o; did you mean '0%s'?", lit.Value, v, lit.Value)
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckPureFunctions(pass *analysis.Pass) (interface{}, error) {
|
||
pure := pass.ResultOf[facts.Purity].(facts.PurityResult)
|
||
|
||
fnLoop:
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
if IsInTest(pass, ssafn) {
|
||
params := ssafn.Signature.Params()
|
||
for i := 0; i < params.Len(); i++ {
|
||
param := params.At(i)
|
||
if IsType(param.Type(), "*testing.B") {
|
||
// Ignore discarded pure functions in code related
|
||
// to benchmarks. Instead of matching BenchmarkFoo
|
||
// functions, we match any function accepting a
|
||
// *testing.B. Benchmarks sometimes call generic
|
||
// functions for doing the actual work, and
|
||
// checking for the parameter is a lot easier and
|
||
// faster than analyzing call trees.
|
||
continue fnLoop
|
||
}
|
||
}
|
||
}
|
||
|
||
for _, b := range ssafn.Blocks {
|
||
for _, ins := range b.Instrs {
|
||
ins, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
continue
|
||
}
|
||
refs := ins.Referrers()
|
||
if refs == nil || len(FilterDebug(*refs)) > 0 {
|
||
continue
|
||
}
|
||
callee := ins.Common().StaticCallee()
|
||
if callee == nil {
|
||
continue
|
||
}
|
||
if callee.Object() == nil {
|
||
// TODO(dh): support anonymous functions
|
||
continue
|
||
}
|
||
if _, ok := pure[callee.Object().(*types.Func)]; ok {
|
||
pass.Reportf(ins.Pos(), "%s is a pure function but its return value is ignored", callee.Name())
|
||
continue
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckDeprecated(pass *analysis.Pass) (interface{}, error) {
|
||
deprs := pass.ResultOf[facts.Deprecated].(facts.DeprecatedResult)
|
||
|
||
// Selectors can appear outside of function literals, e.g. when
|
||
// declaring package level variables.
|
||
|
||
var tfn types.Object
|
||
stack := 0
|
||
fn := func(node ast.Node, push bool) bool {
|
||
if !push {
|
||
stack--
|
||
return false
|
||
}
|
||
stack++
|
||
if stack == 1 {
|
||
tfn = nil
|
||
}
|
||
if fn, ok := node.(*ast.FuncDecl); ok {
|
||
tfn = pass.TypesInfo.ObjectOf(fn.Name)
|
||
}
|
||
sel, ok := node.(*ast.SelectorExpr)
|
||
if !ok {
|
||
return true
|
||
}
|
||
|
||
obj := pass.TypesInfo.ObjectOf(sel.Sel)
|
||
if obj.Pkg() == nil {
|
||
return true
|
||
}
|
||
if pass.Pkg == obj.Pkg() || obj.Pkg().Path()+"_test" == pass.Pkg.Path() {
|
||
// Don't flag stuff in our own package
|
||
return true
|
||
}
|
||
if depr, ok := deprs.Objects[obj]; ok {
|
||
// Look for the first available alternative, not the first
|
||
// version something was deprecated in. If a function was
|
||
// deprecated in Go 1.6, an alternative has been available
|
||
// already in 1.0, and we're targeting 1.2, it still
|
||
// makes sense to use the alternative from 1.0, to be
|
||
// future-proof.
|
||
minVersion := deprecated.Stdlib[SelectorName(pass, sel)].AlternativeAvailableSince
|
||
if !IsGoVersion(pass, minVersion) {
|
||
return true
|
||
}
|
||
|
||
if tfn != nil {
|
||
if _, ok := deprs.Objects[tfn]; ok {
|
||
// functions that are deprecated may use deprecated
|
||
// symbols
|
||
return true
|
||
}
|
||
}
|
||
ReportNodef(pass, sel, "%s is deprecated: %s", Render(pass, sel), depr.Msg)
|
||
return true
|
||
}
|
||
return true
|
||
}
|
||
|
||
imps := map[string]*types.Package{}
|
||
for _, imp := range pass.Pkg.Imports() {
|
||
imps[imp.Path()] = imp
|
||
}
|
||
fn2 := func(node ast.Node) {
|
||
spec := node.(*ast.ImportSpec)
|
||
p := spec.Path.Value
|
||
path := p[1 : len(p)-1]
|
||
imp := imps[path]
|
||
if depr, ok := deprs.Packages[imp]; ok {
|
||
ReportNodef(pass, spec, "Package %s is deprecated: %s", path, depr.Msg)
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Nodes(nil, fn)
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.ImportSpec)(nil)}, fn2)
|
||
return nil, nil
|
||
}
|
||
|
||
func callChecker(rules map[string]CallCheck) func(pass *analysis.Pass) (interface{}, error) {
|
||
return func(pass *analysis.Pass) (interface{}, error) {
|
||
return checkCalls(pass, rules)
|
||
}
|
||
}
|
||
|
||
func checkCalls(pass *analysis.Pass, rules map[string]CallCheck) (interface{}, error) {
|
||
ranges := pass.ResultOf[valueRangesAnalyzer].(map[*ssa.Function]vrp.Ranges)
|
||
fn := func(caller *ssa.Function, site ssa.CallInstruction, callee *ssa.Function) {
|
||
obj, ok := callee.Object().(*types.Func)
|
||
if !ok {
|
||
return
|
||
}
|
||
|
||
r, ok := rules[lint.FuncName(obj)]
|
||
if !ok {
|
||
return
|
||
}
|
||
var args []*Argument
|
||
ssaargs := site.Common().Args
|
||
if callee.Signature.Recv() != nil {
|
||
ssaargs = ssaargs[1:]
|
||
}
|
||
for _, arg := range ssaargs {
|
||
if iarg, ok := arg.(*ssa.MakeInterface); ok {
|
||
arg = iarg.X
|
||
}
|
||
vr := ranges[site.Parent()][arg]
|
||
args = append(args, &Argument{Value: Value{arg, vr}})
|
||
}
|
||
call := &Call{
|
||
Pass: pass,
|
||
Instr: site,
|
||
Args: args,
|
||
Parent: site.Parent(),
|
||
}
|
||
r(call)
|
||
for idx, arg := range call.Args {
|
||
_ = idx
|
||
for _, e := range arg.invalids {
|
||
// path, _ := astutil.PathEnclosingInterval(f.File, edge.Site.Pos(), edge.Site.Pos())
|
||
// if len(path) < 2 {
|
||
// continue
|
||
// }
|
||
// astcall, ok := path[0].(*ast.CallExpr)
|
||
// if !ok {
|
||
// continue
|
||
// }
|
||
// pass.Reportf(astcall.Args[idx], "%s", e)
|
||
|
||
pass.Reportf(site.Pos(), "%s", e)
|
||
}
|
||
}
|
||
for _, e := range call.invalids {
|
||
pass.Reportf(call.Instr.Common().Pos(), "%s", e)
|
||
}
|
||
}
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
eachCall(ssafn, fn)
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func shortCallName(call *ssa.CallCommon) string {
|
||
if call.IsInvoke() {
|
||
return ""
|
||
}
|
||
switch v := call.Value.(type) {
|
||
case *ssa.Function:
|
||
fn, ok := v.Object().(*types.Func)
|
||
if !ok {
|
||
return ""
|
||
}
|
||
return fn.Name()
|
||
case *ssa.Builtin:
|
||
return v.Name()
|
||
}
|
||
return ""
|
||
}
|
||
|
||
func CheckWriterBufferModified(pass *analysis.Pass) (interface{}, error) {
|
||
// TODO(dh): this might be a good candidate for taint analysis.
|
||
// Taint the argument as MUST_NOT_MODIFY, then propagate that
|
||
// through functions like bytes.Split
|
||
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
sig := ssafn.Signature
|
||
if ssafn.Name() != "Write" || sig.Recv() == nil || sig.Params().Len() != 1 || sig.Results().Len() != 2 {
|
||
continue
|
||
}
|
||
tArg, ok := sig.Params().At(0).Type().(*types.Slice)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if basic, ok := tArg.Elem().(*types.Basic); !ok || basic.Kind() != types.Byte {
|
||
continue
|
||
}
|
||
if basic, ok := sig.Results().At(0).Type().(*types.Basic); !ok || basic.Kind() != types.Int {
|
||
continue
|
||
}
|
||
if named, ok := sig.Results().At(1).Type().(*types.Named); !ok || !IsType(named, "error") {
|
||
continue
|
||
}
|
||
|
||
for _, block := range ssafn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
switch ins := ins.(type) {
|
||
case *ssa.Store:
|
||
addr, ok := ins.Addr.(*ssa.IndexAddr)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if addr.X != ssafn.Params[1] {
|
||
continue
|
||
}
|
||
pass.Reportf(ins.Pos(), "io.Writer.Write must not modify the provided buffer, not even temporarily")
|
||
case *ssa.Call:
|
||
if !IsCallTo(ins.Common(), "append") {
|
||
continue
|
||
}
|
||
if ins.Common().Args[0] != ssafn.Params[1] {
|
||
continue
|
||
}
|
||
pass.Reportf(ins.Pos(), "io.Writer.Write must not modify the provided buffer, not even temporarily")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func loopedRegexp(name string) CallCheck {
|
||
return func(call *Call) {
|
||
if len(extractConsts(call.Args[0].Value.Value)) == 0 {
|
||
return
|
||
}
|
||
if !isInLoop(call.Instr.Block()) {
|
||
return
|
||
}
|
||
call.Invalid(fmt.Sprintf("calling %s in a loop has poor performance, consider using regexp.Compile", name))
|
||
}
|
||
}
|
||
|
||
func CheckEmptyBranch(pass *analysis.Pass) (interface{}, error) {
|
||
for _, ssafn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
if ssafn.Syntax() == nil {
|
||
continue
|
||
}
|
||
if IsExample(ssafn) {
|
||
continue
|
||
}
|
||
fn := func(node ast.Node) bool {
|
||
ifstmt, ok := node.(*ast.IfStmt)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if ifstmt.Else != nil {
|
||
b, ok := ifstmt.Else.(*ast.BlockStmt)
|
||
if !ok || len(b.List) != 0 {
|
||
return true
|
||
}
|
||
ReportfFG(pass, ifstmt.Else.Pos(), "empty branch")
|
||
}
|
||
if len(ifstmt.Body.List) != 0 {
|
||
return true
|
||
}
|
||
ReportfFG(pass, ifstmt.Pos(), "empty branch")
|
||
return true
|
||
}
|
||
Inspect(ssafn.Syntax(), fn)
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckMapBytesKey(pass *analysis.Pass) (interface{}, error) {
|
||
for _, fn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, b := range fn.Blocks {
|
||
insLoop:
|
||
for _, ins := range b.Instrs {
|
||
// find []byte -> string conversions
|
||
conv, ok := ins.(*ssa.Convert)
|
||
if !ok || conv.Type() != types.Universe.Lookup("string").Type() {
|
||
continue
|
||
}
|
||
if s, ok := conv.X.Type().(*types.Slice); !ok || s.Elem() != types.Universe.Lookup("byte").Type() {
|
||
continue
|
||
}
|
||
refs := conv.Referrers()
|
||
// need at least two (DebugRef) references: the
|
||
// conversion and the *ast.Ident
|
||
if refs == nil || len(*refs) < 2 {
|
||
continue
|
||
}
|
||
ident := false
|
||
// skip first reference, that's the conversion itself
|
||
for _, ref := range (*refs)[1:] {
|
||
switch ref := ref.(type) {
|
||
case *ssa.DebugRef:
|
||
if _, ok := ref.Expr.(*ast.Ident); !ok {
|
||
// the string seems to be used somewhere
|
||
// unexpected; the default branch should
|
||
// catch this already, but be safe
|
||
continue insLoop
|
||
} else {
|
||
ident = true
|
||
}
|
||
case *ssa.Lookup:
|
||
default:
|
||
// the string is used somewhere else than a
|
||
// map lookup
|
||
continue insLoop
|
||
}
|
||
}
|
||
|
||
// the result of the conversion wasn't assigned to an
|
||
// identifier
|
||
if !ident {
|
||
continue
|
||
}
|
||
pass.Reportf(conv.Pos(), "m[string(key)] would be more efficient than k := string(key); m[k]")
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckRangeStringRunes(pass *analysis.Pass) (interface{}, error) {
|
||
return sharedcheck.CheckRangeStringRunes(pass)
|
||
}
|
||
|
||
func CheckSelfAssignment(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
assign := node.(*ast.AssignStmt)
|
||
if assign.Tok != token.ASSIGN || len(assign.Lhs) != len(assign.Rhs) {
|
||
return
|
||
}
|
||
for i, stmt := range assign.Lhs {
|
||
rlh := Render(pass, stmt)
|
||
rrh := Render(pass, assign.Rhs[i])
|
||
if rlh == rrh {
|
||
ReportfFG(pass, assign.Pos(), "self-assignment of %s to %s", rrh, rlh)
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.AssignStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func buildTagsIdentical(s1, s2 []string) bool {
|
||
if len(s1) != len(s2) {
|
||
return false
|
||
}
|
||
s1s := make([]string, len(s1))
|
||
copy(s1s, s1)
|
||
sort.Strings(s1s)
|
||
s2s := make([]string, len(s2))
|
||
copy(s2s, s2)
|
||
sort.Strings(s2s)
|
||
for i, s := range s1s {
|
||
if s != s2s[i] {
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
|
||
func CheckDuplicateBuildConstraints(pass *analysis.Pass) (interface{}, error) {
|
||
for _, f := range pass.Files {
|
||
constraints := buildTags(f)
|
||
for i, constraint1 := range constraints {
|
||
for j, constraint2 := range constraints {
|
||
if i >= j {
|
||
continue
|
||
}
|
||
if buildTagsIdentical(constraint1, constraint2) {
|
||
ReportfFG(pass, f.Pos(), "identical build constraints %q and %q",
|
||
strings.Join(constraint1, " "),
|
||
strings.Join(constraint2, " "))
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckSillyRegexp(pass *analysis.Pass) (interface{}, error) {
|
||
// We could use the rule checking engine for this, but the
|
||
// arguments aren't really invalid.
|
||
for _, fn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, b := range fn.Blocks {
|
||
for _, ins := range b.Instrs {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
continue
|
||
}
|
||
switch CallName(call.Common()) {
|
||
case "regexp.MustCompile", "regexp.Compile", "regexp.Match", "regexp.MatchReader", "regexp.MatchString":
|
||
default:
|
||
continue
|
||
}
|
||
c, ok := call.Common().Args[0].(*ssa.Const)
|
||
if !ok {
|
||
continue
|
||
}
|
||
s := constant.StringVal(c.Value)
|
||
re, err := syntax.Parse(s, 0)
|
||
if err != nil {
|
||
continue
|
||
}
|
||
if re.Op != syntax.OpLiteral && re.Op != syntax.OpEmptyMatch {
|
||
continue
|
||
}
|
||
pass.Reportf(call.Pos(), "regular expression does not contain any meta characters")
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckMissingEnumTypesInDeclaration(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
decl := node.(*ast.GenDecl)
|
||
if !decl.Lparen.IsValid() {
|
||
return
|
||
}
|
||
if decl.Tok != token.CONST {
|
||
return
|
||
}
|
||
|
||
groups := GroupSpecs(pass.Fset, decl.Specs)
|
||
groupLoop:
|
||
for _, group := range groups {
|
||
if len(group) < 2 {
|
||
continue
|
||
}
|
||
if group[0].(*ast.ValueSpec).Type == nil {
|
||
// first constant doesn't have a type
|
||
continue groupLoop
|
||
}
|
||
for i, spec := range group {
|
||
spec := spec.(*ast.ValueSpec)
|
||
if len(spec.Names) != 1 || len(spec.Values) != 1 {
|
||
continue groupLoop
|
||
}
|
||
switch v := spec.Values[0].(type) {
|
||
case *ast.BasicLit:
|
||
case *ast.UnaryExpr:
|
||
if _, ok := v.X.(*ast.BasicLit); !ok {
|
||
continue groupLoop
|
||
}
|
||
default:
|
||
// if it's not a literal it might be typed, such as
|
||
// time.Microsecond = 1000 * Nanosecond
|
||
continue groupLoop
|
||
}
|
||
if i == 0 {
|
||
continue
|
||
}
|
||
if spec.Type != nil {
|
||
continue groupLoop
|
||
}
|
||
}
|
||
ReportNodef(pass, group[0], "only the first constant in this group has an explicit type")
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.GenDecl)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckTimerResetReturnValue(pass *analysis.Pass) (interface{}, error) {
|
||
for _, fn := range pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs {
|
||
for _, block := range fn.Blocks {
|
||
for _, ins := range block.Instrs {
|
||
call, ok := ins.(*ssa.Call)
|
||
if !ok {
|
||
continue
|
||
}
|
||
if !IsCallTo(call.Common(), "(*time.Timer).Reset") {
|
||
continue
|
||
}
|
||
refs := call.Referrers()
|
||
if refs == nil {
|
||
continue
|
||
}
|
||
for _, ref := range FilterDebug(*refs) {
|
||
ifstmt, ok := ref.(*ssa.If)
|
||
if !ok {
|
||
continue
|
||
}
|
||
|
||
found := false
|
||
for _, succ := range ifstmt.Block().Succs {
|
||
if len(succ.Preds) != 1 {
|
||
// Merge point, not a branch in the
|
||
// syntactical sense.
|
||
|
||
// FIXME(dh): this is broken for if
|
||
// statements a la "if x || y"
|
||
continue
|
||
}
|
||
ssautil.Walk(succ, func(b *ssa.BasicBlock) bool {
|
||
if !succ.Dominates(b) {
|
||
// We've reached the end of the branch
|
||
return false
|
||
}
|
||
for _, ins := range b.Instrs {
|
||
// TODO(dh): we should check that
|
||
// we're receiving from the channel of
|
||
// a time.Timer to further reduce
|
||
// false positives. Not a key
|
||
// priority, considering the rarity of
|
||
// Reset and the tiny likeliness of a
|
||
// false positive
|
||
if ins, ok := ins.(*ssa.UnOp); ok && ins.Op == token.ARROW && IsType(ins.X.Type(), "<-chan time.Time") {
|
||
found = true
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
}
|
||
|
||
if found {
|
||
pass.Reportf(call.Pos(), "it is not possible to use Reset's return value correctly, as there is a race condition between draining the channel and the new timer expiring")
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckToLowerToUpperComparison(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
binExpr := node.(*ast.BinaryExpr)
|
||
|
||
var negative bool
|
||
switch binExpr.Op {
|
||
case token.EQL:
|
||
negative = false
|
||
case token.NEQ:
|
||
negative = true
|
||
default:
|
||
return
|
||
}
|
||
|
||
const (
|
||
lo = "strings.ToLower"
|
||
up = "strings.ToUpper"
|
||
)
|
||
|
||
var call string
|
||
if IsCallToAST(pass, binExpr.X, lo) && IsCallToAST(pass, binExpr.Y, lo) {
|
||
call = lo
|
||
} else if IsCallToAST(pass, binExpr.X, up) && IsCallToAST(pass, binExpr.Y, up) {
|
||
call = up
|
||
} else {
|
||
return
|
||
}
|
||
|
||
bang := ""
|
||
if negative {
|
||
bang = "!"
|
||
}
|
||
|
||
ReportNodef(pass, binExpr, "should use %sstrings.EqualFold(a, b) instead of %s(a) %s %s(b)", bang, call, binExpr.Op, call)
|
||
}
|
||
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.BinaryExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckUnreachableTypeCases(pass *analysis.Pass) (interface{}, error) {
|
||
// Check if T subsumes V in a type switch. T subsumes V if T is an interface and T's method set is a subset of V's method set.
|
||
subsumes := func(T, V types.Type) bool {
|
||
tIface, ok := T.Underlying().(*types.Interface)
|
||
if !ok {
|
||
return false
|
||
}
|
||
|
||
return types.Implements(V, tIface)
|
||
}
|
||
|
||
subsumesAny := func(Ts, Vs []types.Type) (types.Type, types.Type, bool) {
|
||
for _, T := range Ts {
|
||
for _, V := range Vs {
|
||
if subsumes(T, V) {
|
||
return T, V, true
|
||
}
|
||
}
|
||
}
|
||
|
||
return nil, nil, false
|
||
}
|
||
|
||
fn := func(node ast.Node) {
|
||
tsStmt := node.(*ast.TypeSwitchStmt)
|
||
|
||
type ccAndTypes struct {
|
||
cc *ast.CaseClause
|
||
types []types.Type
|
||
}
|
||
|
||
// All asserted types in the order of case clauses.
|
||
ccs := make([]ccAndTypes, 0, len(tsStmt.Body.List))
|
||
for _, stmt := range tsStmt.Body.List {
|
||
cc, _ := stmt.(*ast.CaseClause)
|
||
|
||
// Exclude the 'default' case.
|
||
if len(cc.List) == 0 {
|
||
continue
|
||
}
|
||
|
||
Ts := make([]types.Type, len(cc.List))
|
||
for i, expr := range cc.List {
|
||
Ts[i] = pass.TypesInfo.TypeOf(expr)
|
||
}
|
||
|
||
ccs = append(ccs, ccAndTypes{cc: cc, types: Ts})
|
||
}
|
||
|
||
if len(ccs) <= 1 {
|
||
// Zero or one case clauses, nothing to check.
|
||
return
|
||
}
|
||
|
||
// Check if case clauses following cc have types that are subsumed by cc.
|
||
for i, cc := range ccs[:len(ccs)-1] {
|
||
for _, next := range ccs[i+1:] {
|
||
if T, V, yes := subsumesAny(cc.types, next.types); yes {
|
||
ReportNodef(pass, next.cc, "unreachable case clause: %s will always match before %s", T.String(), V.String())
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.TypeSwitchStmt)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckSingleArgAppend(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
if !IsCallToAST(pass, node, "append") {
|
||
return
|
||
}
|
||
call := node.(*ast.CallExpr)
|
||
if len(call.Args) != 1 {
|
||
return
|
||
}
|
||
ReportfFG(pass, call.Pos(), "x = append(y) is equivalent to x = y")
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.CallExpr)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func CheckStructTags(pass *analysis.Pass) (interface{}, error) {
|
||
fn := func(node ast.Node) {
|
||
for _, field := range node.(*ast.StructType).Fields.List {
|
||
if field.Tag == nil {
|
||
continue
|
||
}
|
||
tags, err := parseStructTag(field.Tag.Value[1 : len(field.Tag.Value)-1])
|
||
if err != nil {
|
||
ReportNodef(pass, field.Tag, "unparseable struct tag: %s", err)
|
||
continue
|
||
}
|
||
for k, v := range tags {
|
||
if len(v) > 1 {
|
||
ReportNodef(pass, field.Tag, "duplicate struct tag %q", k)
|
||
continue
|
||
}
|
||
|
||
switch k {
|
||
case "json":
|
||
checkJSONTag(pass, field, v[0])
|
||
case "xml":
|
||
checkXMLTag(pass, field, v[0])
|
||
}
|
||
}
|
||
}
|
||
}
|
||
pass.ResultOf[inspect.Analyzer].(*inspector.Inspector).Preorder([]ast.Node{(*ast.StructType)(nil)}, fn)
|
||
return nil, nil
|
||
}
|
||
|
||
func checkJSONTag(pass *analysis.Pass, field *ast.Field, tag string) {
|
||
//lint:ignore SA9003 TODO(dh): should we flag empty tags?
|
||
if len(tag) == 0 {
|
||
}
|
||
fields := strings.Split(tag, ",")
|
||
for _, r := range fields[0] {
|
||
if !unicode.IsLetter(r) && !unicode.IsDigit(r) && !strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", r) {
|
||
ReportNodef(pass, field.Tag, "invalid JSON field name %q", fields[0])
|
||
}
|
||
}
|
||
var co, cs, ci int
|
||
for _, s := range fields[1:] {
|
||
switch s {
|
||
case "omitempty":
|
||
co++
|
||
case "":
|
||
// allow stuff like "-,"
|
||
case "string":
|
||
cs++
|
||
// only for string, floating point, integer and bool
|
||
T := Dereference(pass.TypesInfo.TypeOf(field.Type).Underlying()).Underlying()
|
||
basic, ok := T.(*types.Basic)
|
||
if !ok || (basic.Info()&(types.IsBoolean|types.IsInteger|types.IsFloat|types.IsString)) == 0 {
|
||
ReportNodef(pass, field.Tag, "the JSON string option only applies to fields of type string, floating point, integer or bool, or pointers to those")
|
||
}
|
||
case "inline":
|
||
ci++
|
||
default:
|
||
ReportNodef(pass, field.Tag, "unknown JSON option %q", s)
|
||
}
|
||
}
|
||
if co > 1 {
|
||
ReportNodef(pass, field.Tag, `duplicate JSON option "omitempty"`)
|
||
}
|
||
if cs > 1 {
|
||
ReportNodef(pass, field.Tag, `duplicate JSON option "string"`)
|
||
}
|
||
if ci > 1 {
|
||
ReportNodef(pass, field.Tag, `duplicate JSON option "inline"`)
|
||
}
|
||
}
|
||
|
||
func checkXMLTag(pass *analysis.Pass, field *ast.Field, tag string) {
|
||
//lint:ignore SA9003 TODO(dh): should we flag empty tags?
|
||
if len(tag) == 0 {
|
||
}
|
||
fields := strings.Split(tag, ",")
|
||
counts := map[string]int{}
|
||
var exclusives []string
|
||
for _, s := range fields[1:] {
|
||
switch s {
|
||
case "attr", "chardata", "cdata", "innerxml", "comment":
|
||
counts[s]++
|
||
if counts[s] == 1 {
|
||
exclusives = append(exclusives, s)
|
||
}
|
||
case "omitempty", "any":
|
||
counts[s]++
|
||
case "":
|
||
default:
|
||
ReportNodef(pass, field.Tag, "unknown XML option %q", s)
|
||
}
|
||
}
|
||
for k, v := range counts {
|
||
if v > 1 {
|
||
ReportNodef(pass, field.Tag, "duplicate XML option %q", k)
|
||
}
|
||
}
|
||
if len(exclusives) > 1 {
|
||
ReportNodef(pass, field.Tag, "XML options %s are mutually exclusive", strings.Join(exclusives, " and "))
|
||
}
|
||
}
|