1 files changed, 111 insertions, 0 deletions
diff --git a/vendor/github.com/mgechev/revive/rule/range-val-in-closure.go b/vendor/github.com/mgechev/revive/rule/range-val-in-closure.go
new file mode 100644
index 0000000000..857787be38
--- /dev/null
+++ b/vendor/github.com/mgechev/revive/rule/range-val-in-closure.go
@@ -0,0 +1,111 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// RangeValInClosureRule lints given else constructs.
+type RangeValInClosureRule struct{}
+
+// Apply applies the rule to given file.
+func (r *RangeValInClosureRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	walker := rangeValInClosure{
+		onFailure: func(failure lint.Failure) {
+			failures = append(failures, failure)
+		},
+	}
+
+	ast.Walk(walker, file.AST)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (r *RangeValInClosureRule) Name() string {
+	return "range-val-in-closure"
+}
+
+type rangeValInClosure struct {
+	onFailure func(lint.Failure)
+}
+
+func (w rangeValInClosure) Visit(node ast.Node) ast.Visitor {
+
+	// Find the variables updated by the loop statement.
+	var vars []*ast.Ident
+	addVar := func(expr ast.Expr) {
+		if id, ok := expr.(*ast.Ident); ok {
+			vars = append(vars, id)
+		}
+	}
+	var body *ast.BlockStmt
+	switch n := node.(type) {
+	case *ast.RangeStmt:
+		body = n.Body
+		addVar(n.Key)
+		addVar(n.Value)
+	case *ast.ForStmt:
+		body = n.Body
+		switch post := n.Post.(type) {
+		case *ast.AssignStmt:
+			// e.g. for p = head; p != nil; p = p.next
+			for _, lhs := range post.Lhs {
+				addVar(lhs)
+			}
+		case *ast.IncDecStmt:
+			// e.g. for i := 0; i < n; i++
+			addVar(post.X)
+		}
+	}
+	if vars == nil {
+		return w
+	}
+
+	// Inspect a go or defer statement
+	// if it's the last one in the loop body.
+	// (We give up if there are following statements,
+	// because it's hard to prove go isn't followed by wait,
+	// or defer by return.)
+	if len(body.List) == 0 {
+		return w
+	}
+	var last *ast.CallExpr
+	switch s := body.List[len(body.List)-1].(type) {
+	case *ast.GoStmt:
+		last = s.Call
+	case *ast.DeferStmt:
+		last = s.Call
+	default:
+		return w
+	}
+	lit, ok := last.Fun.(*ast.FuncLit)
+	if !ok {
+		return w
+	}
+	if lit.Type == nil {
+		// Not referring to a variable (e.g. struct field name)
+		return w
+	}
+	ast.Inspect(lit.Body, func(n ast.Node) bool {
+		id, ok := n.(*ast.Ident)
+		if !ok || id.Obj == nil {
+			return true
+		}
+		for _, v := range vars {
+			if v.Obj == id.Obj {
+				w.onFailure(lint.Failure{
+					Confidence: 1,
+					Failure:    fmt.Sprintf("loop variable %v captured by func literal", id.Name),
+					Node:       n,
+				})
+			}
+		}
+		return true
+	})
+	return w
+}