+use if_chain::if_chain;
use rustc::hir::*;
use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_lint, lint_array};
-use if_chain::if_chain;
-use rustc::ty::TyKind;
+use rustc::ty;
+use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_errors::Applicability;
-use crate::utils::{any_parent_is_automatically_derived, match_def_path, opt_def_id, paths, span_lint_and_sugg};
+use crate::utils::{any_parent_is_automatically_derived, match_def_path, paths, span_lint_and_sugg};
-
-/// **What it does:** Checks for literal calls to `Default::default()`.
-///
-/// **Why is this bad?** It's more clear to the reader to use the name of the type whose default is
-/// being gotten than the generic `Default`.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// // Bad
-/// let s: String = Default::default();
-///
-/// // Good
-/// let s = String::default();
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for literal calls to `Default::default()`.
+ ///
+ /// **Why is this bad?** It's more clear to the reader to use the name of the type whose default is
+ /// being gotten than the generic `Default`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Bad
+ /// let s: String = Default::default();
+ ///
+ /// // Good
+ /// let s = String::default();
+ /// ```
pub DEFAULT_TRAIT_ACCESS,
pedantic,
"checks for literal calls to Default::default()"
}
-#[derive(Copy, Clone)]
-pub struct DefaultTraitAccess;
-
-impl LintPass for DefaultTraitAccess {
- fn get_lints(&self) -> LintArray {
- lint_array!(DEFAULT_TRAIT_ACCESS)
- }
-}
+declare_lint_pass!(DefaultTraitAccess => [DEFAULT_TRAIT_ACCESS]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DefaultTraitAccess {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
if_chain! {
if let ExprKind::Call(ref path, ..) = expr.node;
- if !any_parent_is_automatically_derived(cx.tcx, expr.id);
+ if !any_parent_is_automatically_derived(cx.tcx, expr.hir_id);
if let ExprKind::Path(ref qpath) = path.node;
- if let Some(def_id) = opt_def_id(cx.tables.qpath_def(qpath, path.hir_id));
- if match_def_path(cx.tcx, def_id, &paths::DEFAULT_TRAIT_METHOD);
+ if let Some(def_id) = cx.tables.qpath_res(qpath, path.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::DEFAULT_TRAIT_METHOD);
then {
match qpath {
QPath::Resolved(..) => {
+ if_chain! {
+ // Detect and ignore <Foo as Default>::default() because these calls do
+ // explicitly name the type.
+ if let ExprKind::Call(ref method, ref _args) = expr.node;
+ if let ExprKind::Path(ref p) = method.node;
+ if let QPath::Resolved(Some(_ty), _path) = p;
+ then {
+ return;
+ }
+ }
+
// TODO: Work out a way to put "whatever the imported way of referencing
// this type in this file" rather than a fully-qualified type.
let expr_ty = cx.tables.expr_ty(expr);
- if let TyKind::Adt(..) = expr_ty.sty {
+ if let ty::Adt(..) = expr_ty.sty {
let replacement = format!("{}::default()", expr_ty);
span_lint_and_sugg(
cx,
expr.span,
&format!("Calling {} is more clear than this expression", replacement),
"try",
- replacement);
+ replacement,
+ Applicability::Unspecified, // First resolve the TODO above
+ );
}
},
QPath::TypeRelative(..) => {},
}
}
- }
+ }
}
}