// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. use crate::rustc::hir::*; use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; use crate::rustc::{declare_tool_lint, lint_array}; use crate::utils::{get_trait_def_id, paths, span_lint}; /// **What it does:** Checks for mis-uses of the serde API. /// /// **Why is this bad?** Serde is very finnicky about how its API should be /// used, but the type system can't be used to enforce it (yet?). /// /// **Known problems:** None. /// /// **Example:** Implementing `Visitor::visit_string` but not /// `Visitor::visit_str`. declare_clippy_lint! { pub SERDE_API_MISUSE, correctness, "various things that will negatively affect your serde experience" } #[derive(Copy, Clone)] pub struct Serde; impl LintPass for Serde { fn get_lints(&self) -> LintArray { lint_array!(SERDE_API_MISUSE) } } impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Serde { fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) { if let ItemKind::Impl(_, _, _, _, Some(ref trait_ref), _, ref items) = item.node { let did = trait_ref.path.def.def_id(); if let Some(visit_did) = get_trait_def_id(cx, &paths::SERDE_DE_VISITOR) { if did == visit_did { let mut seen_str = None; let mut seen_string = None; for item in items { match &*item.ident.as_str() { "visit_str" => seen_str = Some(item.span), "visit_string" => seen_string = Some(item.span), _ => {}, } } if let Some(span) = seen_string { if seen_str.is_none() { span_lint( cx, SERDE_API_MISUSE, span, "you should not implement `visit_string` without also implementing `visit_str`", ); } } } } } } }