87aae77943
Fix #324, relates #314 1. Update gocritic to the latest version 2. Use proper gocritic checkers repo, old repo was archived 3. Get enabled by default gocritic checks in sync with go-critic: don't enable performance, experimental and opinionated checks by default 4. Support of `enabled-tags` options for gocritic 5. Enable almost all gocritic checks for the project 6. Make rich debugging for gocritic 7. Meticulously validate gocritic checks config
128 lines
2.9 KiB
Go
128 lines
2.9 KiB
Go
package checkers
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import (
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"go/ast"
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"go/types"
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"github.com/go-critic/go-critic/checkers/internal/lintutil"
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"github.com/go-lintpack/lintpack"
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"github.com/go-lintpack/lintpack/astwalk"
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"github.com/go-toolsmith/astp"
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)
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func init() {
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var info lintpack.CheckerInfo
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info.Name = "underef"
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info.Tags = []string{"style"}
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info.Params = lintpack.CheckerParams{
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"skipRecvDeref": {
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Value: true,
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Usage: "whether to skip (*x).method() calls where x is a pointer receiver",
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},
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}
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info.Summary = "Detects dereference expressions that can be omitted"
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info.Before = `
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(*k).field = 5
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v := (*a)[5] // only if a is array`
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info.After = `
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k.field = 5
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v := a[5]`
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collection.AddChecker(&info, func(ctx *lintpack.CheckerContext) lintpack.FileWalker {
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c := &underefChecker{ctx: ctx}
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c.skipRecvDeref = info.Params.Bool("skipRecvDeref")
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return astwalk.WalkerForExpr(c)
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})
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}
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type underefChecker struct {
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astwalk.WalkHandler
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ctx *lintpack.CheckerContext
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skipRecvDeref bool
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}
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func (c *underefChecker) VisitExpr(expr ast.Expr) {
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switch n := expr.(type) {
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case *ast.SelectorExpr:
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expr := lintutil.AsParenExpr(n.X)
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if c.skipRecvDeref && c.isPtrRecvMethodCall(n.Sel) {
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return
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}
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if expr, ok := expr.X.(*ast.StarExpr); ok {
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if c.checkStarExpr(expr) {
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c.warnSelect(n)
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}
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}
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case *ast.IndexExpr:
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expr := lintutil.AsParenExpr(n.X)
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if expr, ok := expr.X.(*ast.StarExpr); ok {
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if !c.checkStarExpr(expr) {
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return
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}
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if c.checkArray(expr) {
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c.warnArray(n)
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}
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}
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}
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}
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func (c *underefChecker) isPtrRecvMethodCall(fn *ast.Ident) bool {
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typ, ok := c.ctx.TypesInfo.TypeOf(fn).(*types.Signature)
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if ok && typ != nil && typ.Recv() != nil {
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_, ok := typ.Recv().Type().(*types.Pointer)
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return ok
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}
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return false
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}
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func (c *underefChecker) underef(x *ast.ParenExpr) ast.Expr {
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// If there is only 1 deref, can remove parenthesis,
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// otherwise can remove StarExpr only.
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dereferenced := x.X.(*ast.StarExpr).X
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if astp.IsStarExpr(dereferenced) {
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return &ast.ParenExpr{X: dereferenced}
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}
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return dereferenced
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}
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func (c *underefChecker) warnSelect(expr *ast.SelectorExpr) {
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// TODO: add () to function output.
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c.ctx.Warn(expr, "could simplify %s to %s.%s",
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expr,
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c.underef(expr.X.(*ast.ParenExpr)),
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expr.Sel.Name)
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}
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func (c *underefChecker) warnArray(expr *ast.IndexExpr) {
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c.ctx.Warn(expr, "could simplify %s to %s[%s]",
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expr,
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c.underef(expr.X.(*ast.ParenExpr)),
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expr.Index)
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}
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// checkStarExpr checks if ast.StarExpr could be simplified.
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func (c *underefChecker) checkStarExpr(expr *ast.StarExpr) bool {
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typ, ok := c.ctx.TypesInfo.TypeOf(expr.X).Underlying().(*types.Pointer)
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if !ok {
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return false
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}
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switch typ.Elem().Underlying().(type) {
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case *types.Pointer, *types.Interface:
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return false
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default:
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return true
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}
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}
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func (c *underefChecker) checkArray(expr *ast.StarExpr) bool {
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typ, ok := c.ctx.TypesInfo.TypeOf(expr.X).(*types.Pointer)
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if !ok {
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return false
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}
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_, ok = typ.Elem().(*types.Array)
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return ok
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}
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