-// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use crate::utils::{match_def_path, opt_def_id, paths, snippet, span_lint_and_then, walk_ptrs_ty_depth};
+use crate::utils::{match_def_path, paths, snippet, span_lint_and_then, walk_ptrs_ty_depth};
use if_chain::if_chain;
-use rustc::hir::{Expr, ExprKind};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
use rustc_errors::Applicability;
+use rustc_hir::{BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
use std::iter;
-/// **What it does:** Checks for calls of `mem::discriminant()` on a non-enum type.
-///
-/// **Why is this bad?** The value of `mem::discriminant()` on non-enum types
-/// is unspecified.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// mem::discriminant(&"hello");
-/// mem::discriminant(&&Some(2));
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for calls of `mem::discriminant()` on a non-enum type.
+ ///
+ /// **Why is this bad?** The value of `mem::discriminant()` on non-enum types
+ /// is unspecified.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// use std::mem;
+ ///
+ /// mem::discriminant(&"hello");
+ /// mem::discriminant(&&Some(2));
+ /// ```
pub MEM_DISCRIMINANT_NON_ENUM,
correctness,
- "calling mem::descriminant on non-enum type"
+ "calling `mem::descriminant` on non-enum type"
}
-pub struct MemDiscriminant;
-
-impl LintPass for MemDiscriminant {
- fn get_lints(&self) -> LintArray {
- lint_array![MEM_DISCRIMINANT_NON_ENUM]
- }
-}
+declare_lint_pass!(MemDiscriminant => [MEM_DISCRIMINANT_NON_ENUM]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MemDiscriminant {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+impl<'tcx> LateLintPass<'tcx> for MemDiscriminant {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
- if let ExprKind::Call(ref func, ref func_args) = expr.node;
+ if let ExprKind::Call(ref func, ref func_args) = expr.kind;
// is `mem::discriminant`
- if let ExprKind::Path(ref func_qpath) = func.node;
- if let Some(def_id) = opt_def_id(cx.tables.qpath_def(func_qpath, func.hir_id));
- if match_def_path(cx.tcx, def_id, &paths::MEM_DISCRIMINANT);
+ if let ExprKind::Path(ref func_qpath) = func.kind;
+ if let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::MEM_DISCRIMINANT);
// type is non-enum
- let ty_param = cx.tables.node_substs(func.hir_id).type_at(0);
+ let ty_param = cx.typeck_results().node_substs(func.hir_id).type_at(0);
if !ty_param.is_enum();
then {
MEM_DISCRIMINANT_NON_ENUM,
expr.span,
&format!("calling `mem::discriminant` on non-enum type `{}`", ty_param),
- |db| {
+ |diag| {
// if this is a reference to an enum, suggest dereferencing
let (base_ty, ptr_depth) = walk_ptrs_ty_depth(ty_param);
if ptr_depth >= 1 && base_ty.is_enum() {
let mut derefs_needed = ptr_depth;
let mut cur_expr = param;
while derefs_needed > 0 {
- if let ExprKind::AddrOf(_, ref inner_expr) = cur_expr.node {
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref inner_expr) = cur_expr.kind {
derefs_needed -= 1;
cur_expr = inner_expr;
} else {
}
let derefs: String = iter::repeat('*').take(derefs_needed).collect();
- db.span_suggestion_with_applicability(
+ diag.span_suggestion(
param.span,
"try dereferencing",
format!("{}{}", derefs, snippet(cx, cur_expr.span, "<param>")),