src

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

sa4029.go (2430B)

      1 package sa4029
      2 
      3 import (
      4 	"fmt"
      5 	"go/ast"
      6 	"go/types"
      7 
      8 	"honnef.co/go/tools/analysis/code"
      9 	"honnef.co/go/tools/analysis/edit"
     10 	"honnef.co/go/tools/analysis/lint"
     11 	"honnef.co/go/tools/analysis/report"
     12 	"honnef.co/go/tools/pattern"
     13 
     14 	"golang.org/x/tools/go/analysis"
     15 )
     16 
     17 var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
     18 	Analyzer: &analysis.Analyzer{
     19 		Name:     "SA4029",
     20 		Run:      run,
     21 		Requires: code.RequiredAnalyzers,
     22 	},
     23 	Doc: &lint.RawDocumentation{
     24 		Title: "Ineffective attempt at sorting slice",
     25 		Text: `
     26 \'sort.Float64Slice\', \'sort.IntSlice\', and \'sort.StringSlice\' are
     27 types, not functions. Doing \'x = sort.StringSlice(x)\' does nothing,
     28 especially not sort any values. The correct usage is
     29 \'sort.Sort(sort.StringSlice(x))\' or \'sort.StringSlice(x).Sort()\',
     30 but there are more convenient helpers, namely \'sort.Float64s\',
     31 \'sort.Ints\', and \'sort.Strings\'.
     32 `,
     33 		Since:    "2022.1",
     34 		Severity: lint.SeverityWarning,
     35 		MergeIf:  lint.MergeIfAny,
     36 	},
     37 })
     38 
     39 var Analyzer = SCAnalyzer.Analyzer
     40 
     41 var ineffectiveSortQ = pattern.MustParse(`(AssignStmt target@(Ident _) "=" (CallExpr typ@(Symbol (Or "sort.Float64Slice" "sort.IntSlice" "sort.StringSlice")) [target]))`)
     42 
     43 func run(pass *analysis.Pass) (any, error) {
     44 	for node, m := range code.Matches(pass, ineffectiveSortQ) {
     45 		_, ok := types.Unalias(pass.TypesInfo.TypeOf(m.State["target"].(ast.Expr))).(*types.Slice)
     46 		if !ok {
     47 			// Avoid flagging 'x = sort.StringSlice(x)' where TypeOf(x) == sort.StringSlice
     48 			continue
     49 		}
     50 
     51 		var alternative string
     52 		typeName := types.TypeString(types.Unalias(m.State["typ"].(*types.TypeName).Type()), nil)
     53 		switch typeName {
     54 		case "sort.Float64Slice":
     55 			alternative = "Float64s"
     56 		case "sort.IntSlice":
     57 			alternative = "Ints"
     58 		case "sort.StringSlice":
     59 			alternative = "Strings"
     60 		default:
     61 			panic(fmt.Sprintf("unreachable: %q", typeName))
     62 		}
     63 
     64 		r := &ast.CallExpr{
     65 			Fun: &ast.SelectorExpr{
     66 				X:   &ast.Ident{Name: "sort"},
     67 				Sel: &ast.Ident{Name: alternative},
     68 			},
     69 			Args: []ast.Expr{m.State["target"].(ast.Expr)},
     70 		}
     71 
     72 		report.Report(pass, node,
     73 			fmt.Sprintf("%s is a type, not a function, and %s doesn't sort your values; consider using sort.%s instead",
     74 				typeName,
     75 				report.Render(pass, node.(*ast.AssignStmt).Rhs[0]),
     76 				alternative),
     77 			report.Fixes(edit.Fix(fmt.Sprintf("Replace with call to sort.%s", alternative), edit.ReplaceWithNode(pass.Fset, node, r))))
     78 	}
     79 	return nil, nil
     80 }