src

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git clone git://code.dwrz.net/src
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sa6006.go (1263B)

      1 package sa6006
      2 
      3 import (
      4 	"go/ast"
      5 
      6 	"honnef.co/go/tools/analysis/code"
      7 	"honnef.co/go/tools/analysis/lint"
      8 	"honnef.co/go/tools/analysis/report"
      9 	"honnef.co/go/tools/pattern"
     10 
     11 	"golang.org/x/tools/go/analysis"
     12 )
     13 
     14 var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
     15 	Analyzer: &analysis.Analyzer{
     16 		Name:     "SA6006",
     17 		Run:      run,
     18 		Requires: code.RequiredAnalyzers,
     19 	},
     20 	Doc: &lint.RawDocumentation{
     21 		Title: `Using io.WriteString to write \'[]byte\'`,
     22 		Text: `Using io.WriteString to write a slice of bytes, as in
     23 
     24     io.WriteString(w, string(b))
     25 
     26 is both unnecessary and inefficient. Converting from \'[]byte\' to \'string\'
     27 has to allocate and copy the data, and we could simply use \'w.Write(b)\'
     28 instead.`,
     29 
     30 		Since: "2024.1",
     31 	},
     32 })
     33 
     34 var Analyzer = SCAnalyzer.Analyzer
     35 
     36 var ioWriteStringConversion = pattern.MustParse(`(CallExpr (Symbol "io.WriteString") [_ (CallExpr (Builtin "string") [arg])])`)
     37 
     38 func run(pass *analysis.Pass) (any, error) {
     39 	for node, m := range code.Matches(pass, ioWriteStringConversion) {
     40 		if !code.IsOfStringConvertibleByteSlice(pass, m.State["arg"].(ast.Expr)) {
     41 			continue
     42 		}
     43 		report.Report(pass, node, "use io.Writer.Write instead of converting from []byte to string to use io.WriteString")
     44 	}
     45 	return nil, nil
     46 }