50 lines
1.3 KiB
Go
50 lines
1.3 KiB
Go
package sa5004
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import (
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"go/ast"
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"honnef.co/go/tools/analysis/code"
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"honnef.co/go/tools/analysis/edit"
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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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)
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var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
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Analyzer: &analysis.Analyzer{
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Name: "SA5004",
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Run: run,
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Requires: code.RequiredAnalyzers,
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},
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Doc: &lint.RawDocumentation{
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Title: `\"for { select { ...\" with an empty default branch spins`,
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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 query = pattern.MustParse(`(ForStmt nil nil nil (SelectStmt body))`)
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func run(pass *analysis.Pass) (any, error) {
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for _, m := range code.Matches(pass, query) {
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for _, c := range m.State["body"].([]ast.Stmt) {
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// FIXME this leaves behind an empty line, and possibly
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// comments in the default branch. We can't easily fix
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// either.
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if comm, ok := c.(*ast.CommClause); ok && comm.Comm == nil && len(comm.Body) == 0 {
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report.Report(pass, comm,
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"should not have an empty default case in a for+select loop; the loop will spin",
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report.Fixes(edit.Fix("Remove empty default branch", edit.Delete(comm))))
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// there can only be one default case
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break
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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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