use rustc::hir::*;
use rustc::lint::*;
+use rustc::{declare_lint, lint_array};
+use if_chain::if_chain;
use rustc::ty::{self, Ty};
-use rustc::ty::subst::Substs;
-use rustc_const_eval::ConstContext;
use syntax::codemap::Span;
-use utils::{higher, is_copy, snippet, span_lint_and_sugg};
+use crate::utils::{higher, is_copy, snippet, span_lint_and_sugg};
+use crate::consts::constant;
/// **What it does:** Checks for usage of `&vec![..]` when using `&[..]` would
/// be possible.
/// ```rust,ignore
/// foo(&vec![1, 2])
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub USELESS_VEC,
- Warn,
+ perf,
"useless `vec!`"
}
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
// search for `&vec![_]` expressions where the adjusted type is `&[_]`
if_chain! {
- if let ty::TyRef(_, ref ty) = cx.tables.expr_ty_adjusted(expr).sty;
- if let ty::TySlice(..) = ty.ty.sty;
- if let ExprAddrOf(_, ref addressee) = expr.node;
+ if let ty::TyRef(_, ty, _) = cx.tables.expr_ty_adjusted(expr).sty;
+ if let ty::TySlice(..) = ty.sty;
+ if let ExprKind::AddrOf(_, ref addressee) = expr.node;
if let Some(vec_args) = higher::vec_macro(cx, addressee);
then {
check_vec_macro(cx, &vec_args, expr.span);
fn check_vec_macro<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, vec_args: &higher::VecArgs<'tcx>, span: Span) {
let snippet = match *vec_args {
higher::VecArgs::Repeat(elem, len) => {
- let parent_item = cx.tcx.hir.get_parent(len.id);
- let parent_def_id = cx.tcx.hir.local_def_id(parent_item);
- let substs = Substs::identity_for_item(cx.tcx, parent_def_id);
- if ConstContext::new(cx.tcx, cx.param_env.and(substs), cx.tables)
- .eval(len)
- .is_ok()
- {
+ if constant(cx, cx.tables, len).is_some() {
format!("&[{}; {}]", snippet(cx, elem.span, "elem"), snippet(cx, len.span, "len"))
} else {
return;