53 lines
1.5 KiB
Go
53 lines
1.5 KiB
Go
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package sa4001
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import (
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"go/ast"
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"regexp"
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"honnef.co/go/tools/analysis/code"
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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/pattern"
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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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)
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var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
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Analyzer: &analysis.Analyzer{
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Name: "SA4001",
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Run: run,
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Requires: []*analysis.Analyzer{inspect.Analyzer},
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},
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Doc: &lint.RawDocumentation{
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Title: `\'&*x\' gets simplified to \'x\', it does not copy \'x\'`,
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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 (
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// cgo produces code like fn(&*_Cvar_kSomeCallbacks) which we don't
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// want to flag.
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cgoIdent = regexp.MustCompile(`^_C(func|var)_.+$`)
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checkIneffectiveCopyQ1 = pattern.MustParse(`(UnaryExpr "&" (StarExpr obj))`)
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checkIneffectiveCopyQ2 = pattern.MustParse(`(StarExpr (UnaryExpr "&" _))`)
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)
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func run(pass *analysis.Pass) (any, error) {
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fn := func(node ast.Node) {
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if m, ok := code.Match(pass, checkIneffectiveCopyQ1, node); ok {
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if ident, ok := m.State["obj"].(*ast.Ident); !ok || !cgoIdent.MatchString(ident.Name) {
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report.Report(pass, node, "&*x will be simplified to x. It will not copy x.")
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}
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} else if _, ok := code.Match(pass, checkIneffectiveCopyQ2, node); ok {
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report.Report(pass, node, "*&x will be simplified to x. It will not copy x.")
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}
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}
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code.Preorder(pass, fn, (*ast.UnaryExpr)(nil), (*ast.StarExpr)(nil))
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return nil, nil
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}
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