rust-clippy/clippy_lints/src/serde_api.rs
Konrad Borowski 3f62fc3a7e Remove crate:: prefixes from crate paths
This is somewhat misleading, as those are actually external crates,
and don't need a crate:: prefix.
2018-12-29 16:05:49 +01:00

68 lines
2.5 KiB
Rust

// 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use crate::utils::{get_trait_def_id, paths, span_lint};
use rustc::hir::*;
use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
use rustc::{declare_tool_lint, lint_array};
/// **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`",
);
}
}
}
}
}
}
}