open-nomad/vendor/honnef.co/go/tools/internal/sharedcheck/lint.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

72 lines
1.9 KiB
Go

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
}