func()

in tools/go-agent/instrument/runtime/instrument.go [41:95]

• 53 lines of code
• 12 McCabe index (conditional complexity)

func (r *Instrument) FilterAndEdit(path string, curFile *dst.File, cursor *dstutil.Cursor, allFiles []*dst.File) bool {
	switch n := cursor.Node().(type) {
	case *dst.TypeSpec:
		if n.Name != nil && n.Name.Name != "g" {
			return false
		}
		st, ok := n.Type.(*dst.StructType)
		if !ok {
			return false
		}
		for _, f := range st.Fields.List {
			if len(f.Names) > 0 && f.Names[0].Name == "goid" {
				r.goIDType = f.Type.(*dst.Ident).Name
			}
		}
		// append the tls field
		st.Fields.List = append(st.Fields.List, &dst.Field{
			Names: []*dst.Ident{dst.NewIdent(consts.TLSFieldName)},
			Type:  dst.NewIdent("interface{}")})
		tools.LogWithStructEnhance("runtime", "g", consts.TLSFieldName, "tls field")
		return true
	case *dst.FuncDecl:
		if n.Name.Name != "newproc1" {
			return false
		}
		if len(n.Type.Results.List) != 1 {
			return false
		}
		if len(n.Type.Params.List) != 3 {
			return false
		}
		parameters := tools.EnhanceParameterNames(n.Type.Params, tools.FieldListTypeParam)
		results := tools.EnhanceParameterNames(n.Type.Results, tools.FieldListTypeResult)

		tools.InsertStmtsBeforeBody(n.Body, `defer func() {
	{{(index .Results 0).Name}}.{{.TLSField}} = goroutineChange({{(index .Parameters 1).Name}}.{{.TLSField}})
}()
`, struct {
			Parameters        []*tools.ParameterInfo
			Results           []*tools.ParameterInfo
			TLSField          string
			OperatorField     string
			SnapshotInterface string
		}{
			Parameters:        parameters,
			Results:           results,
			TLSField:          consts.TLSFieldName,
			OperatorField:     consts.GlobalTracerFieldName,
			SnapshotInterface: consts.GlobalTracerSnapshotInterface,
		})
		tools.LogWithMethodEnhance("runtime", "", "newproc1", "support cross goroutine context propagating")
		return true
	}
	return false
}