/// ```rust
/// # use core::iter::repeat;
/// # let len = 4;
+ ///
+ /// // Bad
/// let mut vec1 = Vec::with_capacity(len);
/// vec1.resize(len, 0);
///
/// let mut vec2 = Vec::with_capacity(len);
- /// vec2.extend(repeat(0).take(len))
+ /// vec2.extend(repeat(0).take(len));
+ ///
+ /// // Good
+ /// let mut vec1 = vec![0; len];
+ /// let mut vec2 = vec![0; len];
/// ```
pub SLOW_VECTOR_INITIALIZATION,
perf,
Resize(&'tcx Expr<'tcx>),
}
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SlowVectorInit {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for SlowVectorInit {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
// Matches initialization on reassignements. For example: `vec = Vec::with_capacity(100)`
if_chain! {
if let ExprKind::Assign(ref left, ref right, _) = expr.kind;
}
}
- fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt<'_>) {
+ fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'_>) {
// Matches statements which initializes vectors. For example: `let mut vec = Vec::with_capacity(10)`
if_chain! {
if let StmtKind::Local(ref local) = stmt.kind;
}
/// Search initialization for the given vector
- fn search_initialization<'tcx>(cx: &LateContext<'_, 'tcx>, vec_alloc: VecAllocation<'tcx>, parent_node: HirId) {
+ fn search_initialization<'tcx>(cx: &LateContext<'tcx>, vec_alloc: VecAllocation<'tcx>, parent_node: HirId) {
let enclosing_body = get_enclosing_block(cx, parent_node);
if enclosing_body.is_none() {
}
fn lint_initialization<'tcx>(
- cx: &LateContext<'_, 'tcx>,
+ cx: &LateContext<'tcx>,
initialization: &InitializationType<'tcx>,
vec_alloc: &VecAllocation<'_>,
) {
}
fn emit_lint<'tcx>(
- cx: &LateContext<'_, 'tcx>,
+ cx: &LateContext<'tcx>,
slow_fill: &Expr<'_>,
vec_alloc: &VecAllocation<'_>,
msg: &str,
/// `VectorInitializationVisitor` searches for unsafe or slow vector initializations for the given
/// vector.
struct VectorInitializationVisitor<'a, 'tcx> {
- cx: &'a LateContext<'a, 'tcx>,
+ cx: &'a LateContext<'tcx>,
/// Contains the information.
vec_alloc: VecAllocation<'tcx>,
fn search_slow_extend_filling(&mut self, expr: &'tcx Expr<'_>) {
if_chain! {
if self.initialization_found;
- if let ExprKind::MethodCall(ref path, _, ref args) = expr.kind;
+ if let ExprKind::MethodCall(ref path, _, ref args, _) = expr.kind;
if let ExprKind::Path(ref qpath_subj) = args[0].kind;
if match_qpath(&qpath_subj, &[&*self.vec_alloc.variable_name.as_str()]);
if path.ident.name == sym!(extend);
fn search_slow_resize_filling(&mut self, expr: &'tcx Expr<'_>) {
if_chain! {
if self.initialization_found;
- if let ExprKind::MethodCall(ref path, _, ref args) = expr.kind;
+ if let ExprKind::MethodCall(ref path, _, ref args, _) = expr.kind;
if let ExprKind::Path(ref qpath_subj) = args[0].kind;
if match_qpath(&qpath_subj, &[&*self.vec_alloc.variable_name.as_str()]);
if path.ident.name == sym!(resize);
/// Returns `true` if give expression is `repeat(0).take(...)`
fn is_repeat_take(&self, expr: &Expr<'_>) -> bool {
if_chain! {
- if let ExprKind::MethodCall(ref take_path, _, ref take_args) = expr.kind;
+ if let ExprKind::MethodCall(ref take_path, _, ref take_args, _) = expr.kind;
if take_path.ident.name == sym!(take);
// Check that take is applied to `repeat(0)`