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