73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
package sa1023
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import (
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"go/types"
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"honnef.co/go/tools/analysis/lint"
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"honnef.co/go/tools/analysis/report"
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"honnef.co/go/tools/go/ir"
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"honnef.co/go/tools/go/ir/irutil"
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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: "SA1023",
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Run: run,
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Requires: []*analysis.Analyzer{buildir.Analyzer},
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},
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Doc: &lint.RawDocumentation{
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Title: `Modifying the buffer in an \'io.Writer\' implementation`,
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Text: `\'Write\' must not modify the slice data, even temporarily.`,
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Since: "2017.1",
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Severity: lint.SeverityError,
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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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func run(pass *analysis.Pass) (any, error) {
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// TODO(dh): this might be a good candidate for taint analysis.
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// Taint the argument as MUST_NOT_MODIFY, then propagate that
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// through functions like bytes.Split
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for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
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sig := fn.Signature
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if fn.Name() != "Write" || sig.Recv() == nil {
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continue
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}
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if !types.Identical(sig, knowledge.Signatures["(io.Writer).Write"]) {
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continue
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}
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for _, block := range fn.Blocks {
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for _, ins := range block.Instrs {
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switch ins := ins.(type) {
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case *ir.Store:
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addr, ok := ins.Addr.(*ir.IndexAddr)
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if !ok {
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continue
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}
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if addr.X != fn.Params[1] {
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continue
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}
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report.Report(pass, ins, "io.Writer.Write must not modify the provided buffer, not even temporarily")
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case *ir.Call:
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if !irutil.IsCallTo(ins.Common(), "append") {
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continue
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}
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if ins.Common().Args[0] != fn.Params[1] {
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continue
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}
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report.Report(pass, ins, "io.Writer.Write must not modify the provided buffer, not even temporarily")
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}
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}
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}
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}
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return nil, nil
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}
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