src

Go monorepo.
git clone git://code.dwrz.net/src
Log | Files | Refs

sa1023.go (1913B)

      1 package sa1023
      2 
      3 import (
      4 	"go/types"
      5 
      6 	"honnef.co/go/tools/analysis/lint"
      7 	"honnef.co/go/tools/analysis/report"
      8 	"honnef.co/go/tools/go/ir"
      9 	"honnef.co/go/tools/go/ir/irutil"
     10 	"honnef.co/go/tools/internal/passes/buildir"
     11 	"honnef.co/go/tools/knowledge"
     12 
     13 	"golang.org/x/tools/go/analysis"
     14 )
     15 
     16 var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
     17 	Analyzer: &analysis.Analyzer{
     18 		Name:     "SA1023",
     19 		Run:      run,
     20 		Requires: []*analysis.Analyzer{buildir.Analyzer},
     21 	},
     22 	Doc: &lint.RawDocumentation{
     23 		Title:    `Modifying the buffer in an \'io.Writer\' implementation`,
     24 		Text:     `\'Write\' must not modify the slice data, even temporarily.`,
     25 		Since:    "2017.1",
     26 		Severity: lint.SeverityError,
     27 		MergeIf:  lint.MergeIfAny,
     28 	},
     29 })
     30 
     31 var Analyzer = SCAnalyzer.Analyzer
     32 
     33 func run(pass *analysis.Pass) (any, error) {
     34 	// TODO(dh): this might be a good candidate for taint analysis.
     35 	// Taint the argument as MUST_NOT_MODIFY, then propagate that
     36 	// through functions like bytes.Split
     37 
     38 	for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
     39 		sig := fn.Signature
     40 		if fn.Name() != "Write" || sig.Recv() == nil {
     41 			continue
     42 		}
     43 		if !types.Identical(sig, knowledge.Signatures["(io.Writer).Write"]) {
     44 			continue
     45 		}
     46 
     47 		for _, block := range fn.Blocks {
     48 			for _, ins := range block.Instrs {
     49 				switch ins := ins.(type) {
     50 				case *ir.Store:
     51 					addr, ok := ins.Addr.(*ir.IndexAddr)
     52 					if !ok {
     53 						continue
     54 					}
     55 					if addr.X != fn.Params[1] {
     56 						continue
     57 					}
     58 					report.Report(pass, ins, "io.Writer.Write must not modify the provided buffer, not even temporarily")
     59 				case *ir.Call:
     60 					if !irutil.IsCallTo(ins.Common(), "append") {
     61 						continue
     62 					}
     63 					if ins.Common().Args[0] != fn.Params[1] {
     64 						continue
     65 					}
     66 					report.Report(pass, ins, "io.Writer.Write must not modify the provided buffer, not even temporarily")
     67 				}
     68 			}
     69 		}
     70 	}
     71 	return nil, nil
     72 }