github.com/amarpal/go-tools@v0.0.0-20240422043104-40142f59f616/staticcheck/sa1010/sa1010.go (about)

     1  package sa1010
     2  
     3  import (
     4  	"fmt"
     5  	"go/constant"
     6  
     7  	"github.com/amarpal/go-tools/analysis/callcheck"
     8  	"github.com/amarpal/go-tools/analysis/lint"
     9  	"github.com/amarpal/go-tools/go/ir"
    10  	"github.com/amarpal/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:     "SA1010",
    18  		Requires: []*analysis.Analyzer{buildir.Analyzer},
    19  		Run:      callcheck.Analyzer(checkRegexpFindAllRules),
    20  	},
    21  	Doc: &lint.Documentation{
    22  		Title: `\'(*regexp.Regexp).FindAll\' called with \'n == 0\', which will always return zero results`,
    23  		Text: `If \'n >= 0\', the function returns at most \'n\' matches/submatches. To
    24  return all results, specify a negative number.`,
    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 checkRegexpFindAllRules = map[string]callcheck.Check{
    34  	"(*regexp.Regexp).FindAll":                    RepeatZeroTimes("a FindAll method", 1),
    35  	"(*regexp.Regexp).FindAllIndex":               RepeatZeroTimes("a FindAll method", 1),
    36  	"(*regexp.Regexp).FindAllString":              RepeatZeroTimes("a FindAll method", 1),
    37  	"(*regexp.Regexp).FindAllStringIndex":         RepeatZeroTimes("a FindAll method", 1),
    38  	"(*regexp.Regexp).FindAllStringSubmatch":      RepeatZeroTimes("a FindAll method", 1),
    39  	"(*regexp.Regexp).FindAllStringSubmatchIndex": RepeatZeroTimes("a FindAll method", 1),
    40  	"(*regexp.Regexp).FindAllSubmatch":            RepeatZeroTimes("a FindAll method", 1),
    41  	"(*regexp.Regexp).FindAllSubmatchIndex":       RepeatZeroTimes("a FindAll method", 1),
    42  }
    43  
    44  func RepeatZeroTimes(name string, arg int) callcheck.Check {
    45  	return func(call *callcheck.Call) {
    46  		arg := call.Args[arg]
    47  		if k, ok := arg.Value.Value.(*ir.Const); ok && k.Value.Kind() == constant.Int {
    48  			if v, ok := constant.Int64Val(k.Value); ok && v == 0 {
    49  				arg.Invalid(fmt.Sprintf("calling %s with n == 0 will return no results, did you mean -1?", name))
    50  			}
    51  		}
    52  	}
    53  }