119 lines
2.8 KiB
Go
119 lines
2.8 KiB
Go
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package s1021
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import (
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"go/ast"
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"go/token"
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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/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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"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: "S1021",
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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: `Merge variable declaration and assignment`,
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Before: `
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var x uint
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x = 1`,
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After: `var x uint = 1`,
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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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func run(pass *analysis.Pass) (any, error) {
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hasMultipleAssignments := func(root ast.Node, ident *ast.Ident) bool {
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num := 0
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ast.Inspect(root, func(node ast.Node) bool {
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if num >= 2 {
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return false
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}
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assign, ok := node.(*ast.AssignStmt)
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if !ok {
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return true
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}
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for _, lhs := range assign.Lhs {
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if oident, ok := lhs.(*ast.Ident); ok {
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if pass.TypesInfo.ObjectOf(oident) == pass.TypesInfo.ObjectOf(ident) {
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num++
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}
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}
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}
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return true
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})
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return num >= 2
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}
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fn := func(node ast.Node) {
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block := node.(*ast.BlockStmt)
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if len(block.List) < 2 {
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return
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}
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for i, stmt := range block.List[:len(block.List)-1] {
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_ = i
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decl, ok := stmt.(*ast.DeclStmt)
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if !ok {
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continue
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}
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gdecl, ok := decl.Decl.(*ast.GenDecl)
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if !ok || gdecl.Tok != token.VAR || len(gdecl.Specs) != 1 {
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continue
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}
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vspec, ok := gdecl.Specs[0].(*ast.ValueSpec)
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if !ok || len(vspec.Names) != 1 || len(vspec.Values) != 0 {
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continue
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}
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assign, ok := block.List[i+1].(*ast.AssignStmt)
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if !ok || assign.Tok != token.ASSIGN {
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continue
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}
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if len(assign.Lhs) != 1 || len(assign.Rhs) != 1 {
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continue
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}
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ident, ok := assign.Lhs[0].(*ast.Ident)
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if !ok {
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continue
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}
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if pass.TypesInfo.ObjectOf(vspec.Names[0]) != pass.TypesInfo.ObjectOf(ident) {
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continue
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}
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if code.RefersTo(pass, assign.Rhs[0], pass.TypesInfo.ObjectOf(ident)) {
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continue
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}
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if hasMultipleAssignments(block, ident) {
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continue
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}
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r := &ast.GenDecl{
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Specs: []ast.Spec{
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&ast.ValueSpec{
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Names: vspec.Names,
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Values: []ast.Expr{assign.Rhs[0]},
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Type: vspec.Type,
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},
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},
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Tok: gdecl.Tok,
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}
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report.Report(pass, decl, "should merge variable declaration with assignment on next line",
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report.FilterGenerated(),
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report.Fixes(edit.Fix("Merge declaration with assignment", edit.ReplaceWithNode(pass.Fset, edit.Range{decl.Pos(), assign.End()}, r))))
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}
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}
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code.Preorder(pass, fn, (*ast.BlockStmt)(nil))
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return nil, nil
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}
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