use crate::utils::sugg::Sugg;
use crate::utils::{
- differing_macro_contexts, match_type, paths, snippet, span_lint_and_then, walk_ptrs_ty, SpanlessEq,
+ differing_macro_contexts, is_type_diagnostic_item, match_type, paths, snippet, span_lint_and_then, walk_ptrs_ty,
+ SpanlessEq,
};
use if_chain::if_chain;
use matches::matches;
use rustc::hir::*;
use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
use rustc::ty;
-use rustc::{declare_tool_lint, lint_array};
+use rustc::{declare_lint_pass, declare_tool_lint};
use rustc_errors::Applicability;
+use syntax_pos::Symbol;
declare_clippy_lint! {
/// **What it does:** Checks for manual swapping.
///
/// **Example:**
/// ```rust
+ /// let mut a = 42;
+ /// let mut b = 1337;
+ ///
/// let t = b;
/// b = a;
/// a = t;
/// ```
/// Use std::mem::swap():
/// ```rust
+ /// let mut a = 1;
+ /// let mut b = 2;
/// std::mem::swap(&mut a, &mut b);
/// ```
pub MANUAL_SWAP,
/// a = b;
/// b = a;
/// ```
+ /// Could be written as:
+ /// ```rust
+ /// # let mut a = 1;
+ /// # let mut b = 2;
+ /// std::mem::swap(&mut a, &mut b);
+ /// ```
pub ALMOST_SWAPPED,
correctness,
"`foo = bar; bar = foo` sequence"
}
-#[derive(Copy, Clone)]
-pub struct Swap;
-
-impl LintPass for Swap {
- fn get_lints(&self) -> LintArray {
- lint_array![MANUAL_SWAP, ALMOST_SWAPPED]
- }
-
- fn name(&self) -> &'static str {
- "Swap"
- }
-}
+declare_lint_pass!(Swap => [MANUAL_SWAP, ALMOST_SWAPPED]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Swap {
fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx Block) {
if matches!(ty.sty, ty::Slice(_)) ||
matches!(ty.sty, ty::Array(_, _)) ||
- match_type(cx, ty, &paths::VEC) ||
+ is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")) ||
match_type(cx, ty, &paths::VEC_DEQUE) {
return Some((lhs1, idx1, idx2));
}
None
}
+ if let ExprKind::Field(ref lhs1, _) = lhs1.node {
+ if let ExprKind::Field(ref lhs2, _) = lhs2.node {
+ if lhs1.hir_id.owner_def_id() == lhs2.hir_id.owner_def_id() {
+ return;
+ }
+ }
+ }
+
let (replace, what, sugg) = if let Some((slice, idx1, idx2)) = check_for_slice(cx, lhs1, lhs2) {
if let Some(slice) = Sugg::hir_opt(cx, slice) {
(false,