72 lines
2.3 KiB
Go
72 lines
2.3 KiB
Go
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package s1019
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import (
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"fmt"
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"go/ast"
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"go/types"
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"path/filepath"
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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/go/types/typeutil"
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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: "S1019",
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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: `Simplify \"make\" call by omitting redundant arguments`,
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Text: `The \"make\" function has default values for the length and capacity
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arguments. For channels, the length defaults to zero, and for slices,
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the capacity defaults to the length.`,
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Since: "2017.1",
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// MergeIfAll because the type might be different under different build tags.
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// You shouldn't write code like that…
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MergeIf: lint.MergeIfAll,
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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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checkMakeLenCapQ1 = pattern.MustParse(`(CallExpr (Builtin "make") [typ size@(IntegerLiteral "0")])`)
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checkMakeLenCapQ2 = pattern.MustParse(`(CallExpr (Builtin "make") [typ size size])`)
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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 pass.Pkg.Path() == "runtime_test" && filepath.Base(pass.Fset.Position(node.Pos()).Filename) == "map_test.go" {
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// special case of runtime tests testing map creation
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return
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}
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if m, ok := code.Match(pass, checkMakeLenCapQ1, node); ok {
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T := m.State["typ"].(ast.Expr)
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size := m.State["size"].(ast.Node)
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if _, ok := typeutil.CoreType(pass.TypesInfo.TypeOf(T)).Underlying().(*types.Chan); ok {
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report.Report(pass, size, fmt.Sprintf("should use make(%s) instead", report.Render(pass, T)), report.FilterGenerated())
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}
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} else if m, ok := code.Match(pass, checkMakeLenCapQ2, node); ok {
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// TODO(dh): don't consider sizes identical if they're
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// dynamic. for example: make(T, <-ch, <-ch).
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T := m.State["typ"].(ast.Expr)
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size := m.State["size"].(ast.Node)
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report.Report(pass, size,
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fmt.Sprintf("should use make(%s, %s) instead", report.Render(pass, T), report.Render(pass, size)),
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report.FilterGenerated())
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}
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}
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code.Preorder(pass, fn, (*ast.CallExpr)(nil))
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return nil, nil
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}
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