src

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git clone git://code.dwrz.net/src
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sa1018.go (1384B)

      1 package sa1018
      2 
      3 import (
      4 	"fmt"
      5 	"go/constant"
      6 
      7 	"honnef.co/go/tools/analysis/callcheck"
      8 	"honnef.co/go/tools/analysis/lint"
      9 	"honnef.co/go/tools/go/ir"
     10 	"honnef.co/go/tools/internal/passes/buildir"
     11 
     12 	"golang.org/x/tools/go/analysis"
     13 )
     14 
     15 var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
     16 	Analyzer: &analysis.Analyzer{
     17 		Name:     "SA1018",
     18 		Requires: []*analysis.Analyzer{buildir.Analyzer},
     19 		Run:      callcheck.Analyzer(rules),
     20 	},
     21 	Doc: &lint.RawDocumentation{
     22 		Title: `\'strings.Replace\' called with \'n == 0\', which does nothing`,
     23 		Text: `With \'n == 0\', zero instances will be replaced. To replace all
     24 instances, use a negative number, or use \'strings.ReplaceAll\'.`,
     25 		Since:    "2017.1",
     26 		Severity: lint.SeverityWarning,
     27 		MergeIf:  lint.MergeIfAny, // MergeIfAny if we only flag literals, not named constants
     28 	},
     29 })
     30 
     31 var Analyzer = SCAnalyzer.Analyzer
     32 
     33 var rules = map[string]callcheck.Check{
     34 	"strings.Replace": check("strings.Replace", 3),
     35 	"bytes.Replace":   check("bytes.Replace", 3),
     36 }
     37 
     38 func check(name string, arg int) callcheck.Check {
     39 	return func(call *callcheck.Call) {
     40 		arg := call.Args[arg]
     41 		if k, ok := arg.Value.Value.(*ir.Const); ok && k.Value.Kind() == constant.Int {
     42 			if v, ok := constant.Int64Val(k.Value); ok && v == 0 {
     43 				arg.Invalid(fmt.Sprintf("calling %s with n == 0 will return no results, did you mean -1?", name))
     44 			}
     45 		}
     46 	}
     47 }