+++ /dev/null
-package sharedcheck
-
-import (
- "go/ast"
- "go/types"
-
- "golang.org/x/tools/go/analysis"
- "honnef.co/go/tools/code"
- "honnef.co/go/tools/internal/passes/buildir"
- "honnef.co/go/tools/ir"
- . "honnef.co/go/tools/lint/lintdsl"
-)
-
-func CheckRangeStringRunes(pass *analysis.Pass) (interface{}, error) {
- for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
- cb := func(node ast.Node) bool {
- rng, ok := node.(*ast.RangeStmt)
- if !ok || !code.IsBlank(rng.Key) {
- return true
- }
-
- v, _ := fn.ValueForExpr(rng.X)
-
- // Check that we're converting from string to []rune
- val, _ := v.(*ir.Convert)
- if val == nil {
- return true
- }
- Tsrc, ok := val.X.Type().(*types.Basic)
- if !ok || Tsrc.Kind() != types.String {
- return true
- }
- Tdst, ok := val.Type().(*types.Slice)
- if !ok {
- return true
- }
- TdstElem, ok := Tdst.Elem().(*types.Basic)
- if !ok || TdstElem.Kind() != types.Int32 {
- return true
- }
-
- // Check that the result of the conversion is only used to
- // range over
- refs := val.Referrers()
- if refs == nil {
- return true
- }
-
- // Expect two refs: one for obtaining the length of the slice,
- // one for accessing the elements
- if len(code.FilterDebug(*refs)) != 2 {
- // TODO(dh): right now, we check that only one place
- // refers to our slice. This will miss cases such as
- // ranging over the slice twice. Ideally, we'd ensure that
- // the slice is only used for ranging over (without
- // accessing the key), but that is harder to do because in
- // IR form, ranging over a slice looks like an ordinary
- // loop with index increments and slice accesses. We'd
- // have to look at the associated AST node to check that
- // it's a range statement.
- return true
- }
-
- pass.Reportf(rng.Pos(), "should range over string, not []rune(string)")
-
- return true
- }
- Inspect(fn.Source(), cb)
- }
- return nil, nil
-}