107 lines
2.4 KiB
Go
107 lines
2.4 KiB
Go
package sa4009
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import (
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"fmt"
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"go/ast"
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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/ir"
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"honnef.co/go/tools/go/ir/irutil"
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"honnef.co/go/tools/internal/passes/buildir"
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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: "SA4009",
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Run: run,
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Requires: []*analysis.Analyzer{buildir.Analyzer},
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},
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Doc: &lint.RawDocumentation{
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Title: `A function argument is overwritten before its first use`,
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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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func run(pass *analysis.Pass) (any, error) {
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for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
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cb := func(node ast.Node) bool {
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var typ *ast.FuncType
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var body *ast.BlockStmt
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switch fn := node.(type) {
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case *ast.FuncDecl:
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typ = fn.Type
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body = fn.Body
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case *ast.FuncLit:
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typ = fn.Type
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body = fn.Body
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}
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if body == nil {
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return true
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}
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if len(typ.Params.List) == 0 {
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return true
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}
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for _, field := range typ.Params.List {
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for _, arg := range field.Names {
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obj := pass.TypesInfo.ObjectOf(arg)
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var irobj *ir.Parameter
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for _, param := range fn.Params {
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if param.Object() == obj {
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irobj = param
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break
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}
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}
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if irobj == nil {
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continue
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}
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refs := irobj.Referrers()
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if refs == nil {
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continue
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}
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if len(irutil.FilterDebug(*refs)) != 0 {
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continue
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}
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var assignment ast.Node
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ast.Inspect(body, func(node ast.Node) bool {
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if assignment != nil {
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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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ident, ok := lhs.(*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(ident) == obj {
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assignment = assign
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return false
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}
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}
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return true
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})
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if assignment != nil {
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report.Report(pass, arg, fmt.Sprintf("argument %s is overwritten before first use", arg),
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report.Related(assignment, fmt.Sprintf("assignment to %s", arg)))
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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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if source := fn.Source(); source != nil {
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ast.Inspect(source, cb)
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}
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}
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return nil, nil
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}
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