65 lines
1.8 KiB
Go
65 lines
1.8 KiB
Go
package sa1017
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import (
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"go/constant"
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"honnef.co/go/tools/analysis/callcheck"
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"honnef.co/go/tools/analysis/lint"
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"honnef.co/go/tools/go/ir"
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"honnef.co/go/tools/internal/passes/buildir"
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"honnef.co/go/tools/knowledge"
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"golang.org/x/tools/go/analysis"
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)
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var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
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Analyzer: &analysis.Analyzer{
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Name: "SA1017",
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Requires: []*analysis.Analyzer{buildir.Analyzer},
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Run: callcheck.Analyzer(rules),
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},
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Doc: &lint.RawDocumentation{
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Title: `Channels used with \'os/signal.Notify\' should be buffered`,
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Text: `The \'os/signal\' package uses non-blocking channel sends when delivering
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signals. If the receiving end of the channel isn't ready and the
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channel is either unbuffered or full, the signal will be dropped. To
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avoid missing signals, the channel should be buffered and of the
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appropriate size. For a channel used for notification of just one
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signal value, a buffer of size 1 is sufficient.`,
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Since: "2017.1",
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Severity: lint.SeverityWarning,
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MergeIf: lint.MergeIfAny,
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},
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})
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var Analyzer = SCAnalyzer.Analyzer
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var rules = map[string]callcheck.Check{
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"os/signal.Notify": func(call *callcheck.Call) {
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arg := call.Args[knowledge.Arg("os/signal.Notify.c")]
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if isUnbufferedChannel(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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func isUnbufferedChannel(v callcheck.Value) bool {
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// TODO(dh): this check of course misses many cases of unbuffered
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// channels, such as any in phi or sigma nodes. We'll eventually
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// replace this function.
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val := v.Value
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if ct, ok := val.(*ir.ChangeType); ok {
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val = ct.X
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}
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mk, ok := val.(*ir.MakeChan)
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if !ok {
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return false
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}
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if k, ok := mk.Size.(*ir.Const); ok && k.Value.Kind() == constant.Int {
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if v, ok := constant.Int64Val(k.Value); ok && v == 0 {
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return true
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}
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}
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return false
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}
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