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[significant_drop_tightening] Ignore inexpensive statements

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This commit is contained in:
Caio 2023-02-16 18:34:33 -03:00
parent dfe23dc236
commit 747f81ecd0
4 changed files with 38 additions and 8 deletions
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24
clippy_lints/src/significant_drop_tightening.rs
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@ -61,6 +61,18 @@ pub struct SignificantDropTightening<'tcx> {
}
impl<'tcx> SignificantDropTightening<'tcx> {
/// Searches for at least one statement that could slow down the release of a significant drop.
fn at_least_one_stmt_is_expensive(stmts: &[hir::Stmt<'_>]) -> bool {
for stmt in stmts {
match stmt.kind {
hir::StmtKind::Local(local) if let Some(expr) = local.init
&& let hir::ExprKind::Path(_) = expr.kind => {},
_ => return true
};
}
false
}
/// Verifies if the expression is of type `drop(some_lock_path)` to assert that the temporary
/// is already being dropped before the end of its scope.
fn has_drop(expr: &'tcx hir::Expr<'_>, init_bind_ident: Ident) -> bool {
@ -198,13 +210,15 @@ impl<'tcx> LateLintPass<'tcx> for SignificantDropTightening<'tcx> {
}
self.modify_sdap_if_sig_drop_exists(cx, expr, idx, &mut sdap, stmt, |_| {});
},
_ => continue
_ => {}
};
}
if sdap.number_of_stmts > 1 && {
let last_stmts_idx = block.stmts.len().wrapping_sub(1);
sdap.last_use_stmt_idx != last_stmts_idx
} {
let stmts_after_last_use = sdap
.last_use_stmt_idx
.checked_add(1)
.and_then(|idx| block.stmts.get(idx..))
.unwrap_or_default();
if sdap.number_of_stmts > 1 && Self::at_least_one_stmt_is_expensive(stmts_after_last_use) {
span_lint_and_then(
cx,
SIGNIFICANT_DROP_TIGHTENING,