72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
package s1000
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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/facts/generated"
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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: "S1000",
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Run: run,
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Requires: []*analysis.Analyzer{inspect.Analyzer, generated.Analyzer},
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},
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Doc: &lint.RawDocumentation{
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Title: `Use plain channel send or receive instead of single-case select`,
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Text: `Select statements with a single case can be replaced with a simple
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send or receive.`,
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Before: `
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select {
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case x := <-ch:
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fmt.Println(x)
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}`,
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After: `
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x := <-ch
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fmt.Println(x)
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`,
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Since: "2017.1",
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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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checkSingleCaseSelectQ1 = pattern.MustParse(`
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(ForStmt
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nil nil nil
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select@(SelectStmt
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(CommClause
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(Or
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(UnaryExpr "<-" _)
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(AssignStmt _ _ (UnaryExpr "<-" _)))
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_)))`)
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checkSingleCaseSelectQ2 = pattern.MustParse(`(SelectStmt (CommClause _ _))`)
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)
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func run(pass *analysis.Pass) (any, error) {
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seen := map[ast.Node]struct{}{}
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fn := func(node ast.Node) {
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if m, ok := code.Match(pass, checkSingleCaseSelectQ1, node); ok {
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seen[m.State["select"].(ast.Node)] = struct{}{}
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report.Report(pass, node, "should use for range instead of for { select {} }", report.FilterGenerated())
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} else if _, ok := code.Match(pass, checkSingleCaseSelectQ2, node); ok {
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if _, ok := seen[node]; !ok {
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report.Report(pass, node, "should use a simple channel send/receive instead of select with a single case",
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report.ShortRange(),
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report.FilterGenerated())
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}
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}
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}
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code.Preorder(pass, fn, (*ast.ForStmt)(nil), (*ast.SelectStmt)(nil))
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return nil, nil
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}
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