| use crate::utils::{get_trait_def_id, paths, span_lint}; |
| use rustc_hir::{Item, ItemKind}; |
| use rustc_lint::{LateContext, LateLintPass}; |
| use rustc_session::{declare_lint_pass, declare_tool_lint}; |
| |
| declare_clippy_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`. |
| pub SERDE_API_MISUSE, |
| correctness, |
| "various things that will negatively affect your serde experience" |
| } |
| |
| declare_lint_pass!(SerdeAPI => [SERDE_API_MISUSE]); |
| |
| impl<'tcx> LateLintPass<'tcx> for SerdeAPI { |
| fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) { |
| if let ItemKind::Impl { |
| of_trait: Some(ref trait_ref), |
| items, |
| .. |
| } = item.kind |
| { |
| let did = trait_ref.path.res.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`", |
| ); |
| } |
| } |
| } |
| } |
| } |
| } |
| } |