tools/syz-linter: suggest any instead of interface{}

Any is the preferred over interface{} now in Go.

Author: dvyukov

tools/syz-linter/linter.go

@@ -77,6 +77,8 @@ func run(p *analysis.Pass) (any, error) {
 				pass.checkIfStmt(n)
 			case *ast.AssignStmt:
 				pass.checkAssignStmt(n)
+			case *ast.InterfaceType:
+				pass.checkInterfaceType(n)
 			}
 			return true
 		})
@@ -406,3 +408,9 @@ func (pass *Pass) checkAssignStmt(n *ast.AssignStmt) {
 	}
 	pass.report(n, "Don't duplicate loop variables. They are per-iter (not per-loop) since go122.")
 }
+
+func (pass *Pass) checkInterfaceType(n *ast.InterfaceType) {
+	if len(n.Methods.List) == 0 {
+		pass.report(n, "Use any instead of interface{}")
+	}
+}

tools/syz-linter/testdata/src/lintertest/lintertest.go

@@ -144,3 +144,11 @@ func loopvar() {
 		_, _ = i, v
 	}
 }
+
+func anyInterface() interface{} {	// want "Use any instead of interface{}"
+	var v interface{}		// want "Use any instead of interface{}"
+	func(interface{}) {} (v)	// want "Use any instead of interface{}"
+	var y any
+	func(any) {} (y)
+	return v
+}