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use crate::utils::{get_trait_def_id, paths, span_lint};
use rustc_hir::*;
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<'a, 'tcx> LateLintPass<'a, 'tcx> for SerdeAPI {
fn check_item(&mut self, cx: &LateContext<'a, '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`",
);
}
}
}
}
}
}
}
|
