-// 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.
-
-
#![allow(clippy::default_hash_types)]
use crate::consts::{constant, Constant};
fn get_lints(&self) -> LintArray {
lint_array!(BOX_VEC, VEC_BOX, OPTION_OPTION, LINKEDLIST, BORROWED_BOX)
}
+
+ fn name(&self) -> &'static str {
+ "Types"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TypePass {
check_fn_decl(cx, decl);
}
- fn check_struct_field(&mut self, cx: &LateContext<'_, '_>, field: &StructField) {
+ fn check_struct_field(&mut self, cx: &LateContext<'_, '_>, field: &hir::StructField) {
check_ty(cx, &field.ty, false);
}
///
/// The parameter `is_local` distinguishes the context of the type; types from
/// local bindings should only be checked for the `BORROWED_BOX` lint.
-fn check_ty(cx: &LateContext<'_, '_>, ast_ty: &hir::Ty, is_local: bool) {
- if in_macro(ast_ty.span) {
+fn check_ty(cx: &LateContext<'_, '_>, hir_ty: &hir::Ty, is_local: bool) {
+ if in_macro(hir_ty.span) {
return;
}
- match ast_ty.node {
+ match hir_ty.node {
TyKind::Path(ref qpath) if !is_local => {
- let hir_id = cx.tcx.hir().node_to_hir_id(ast_ty.id);
+ let hir_id = cx.tcx.hir().node_to_hir_id(hir_ty.id);
let def = cx.tables.qpath_def(qpath, hir_id);
if let Some(def_id) = opt_def_id(def) {
if Some(def_id) == cx.tcx.lang_items().owned_box() {
span_help_and_lint(
cx,
BOX_VEC,
- ast_ty.span,
+ hir_ty.span,
"you seem to be trying to use `Box<Vec<T>>`. Consider using just `Vec<T>`",
"`Vec<T>` is already on the heap, `Box<Vec<T>>` makes an extra allocation.",
);
if Some(def_id) == cx.tcx.lang_items().owned_box();
// At this point, we know ty is Box<T>, now get T
if let Some(ref last) = last_path_segment(ty_qpath).args;
- if let Some(ty) = last.args.iter().find_map(|arg| match arg {
+ if let Some(boxed_ty) = last.args.iter().find_map(|arg| match arg {
GenericArg::Type(ty) => Some(ty),
GenericArg::Lifetime(_) => None,
});
- if let TyKind::Path(ref ty_qpath) = ty.node;
- let def = cx.tables.qpath_def(ty_qpath, ty.hir_id);
- if let Some(def_id) = opt_def_id(def);
- let boxed_type = cx.tcx.type_of(def_id);
- if boxed_type.is_sized(cx.tcx.at(ty.span), cx.param_env);
then {
- span_lint_and_sugg(
- cx,
- VEC_BOX,
- ast_ty.span,
- "`Vec<T>` is already on the heap, the boxing is unnecessary.",
- "try",
- format!("Vec<{}>", boxed_type),
- Applicability::MaybeIncorrect,
- );
- return; // don't recurse into the type
+ let ty_ty = hir_ty_to_ty(cx.tcx, boxed_ty);
+ if ty_ty.is_sized(cx.tcx.at(ty.span), cx.param_env) {
+ span_lint_and_sugg(
+ cx,
+ VEC_BOX,
+ hir_ty.span,
+ "`Vec<T>` is already on the heap, the boxing is unnecessary.",
+ "try",
+ format!("Vec<{}>", ty_ty),
+ Applicability::MachineApplicable,
+ );
+ return; // don't recurse into the type
+ }
}
}
} else if match_def_path(cx.tcx, def_id, &paths::OPTION) {
span_lint(
cx,
OPTION_OPTION,
- ast_ty.span,
+ hir_ty.span,
"consider using `Option<T>` instead of `Option<Option<T>>` or a custom \
enum if you need to distinguish all 3 cases",
);
span_help_and_lint(
cx,
LINKEDLIST,
- ast_ty.span,
+ hir_ty.span,
"I see you're using a LinkedList! Perhaps you meant some other data structure?",
"a VecDeque might work",
);
},
}
},
- TyKind::Rptr(ref lt, ref mut_ty) => check_ty_rptr(cx, ast_ty, is_local, lt, mut_ty),
+ TyKind::Rptr(ref lt, ref mut_ty) => check_ty_rptr(cx, hir_ty, is_local, lt, mut_ty),
// recurse
TyKind::Slice(ref ty) | TyKind::Array(ref ty, _) | TyKind::Ptr(MutTy { ref ty, .. }) => {
check_ty(cx, ty, is_local)
}
}
-fn check_ty_rptr(cx: &LateContext<'_, '_>, ast_ty: &hir::Ty, is_local: bool, lt: &Lifetime, mut_ty: &MutTy) {
+fn check_ty_rptr(cx: &LateContext<'_, '_>, hir_ty: &hir::Ty, is_local: bool, lt: &Lifetime, mut_ty: &MutTy) {
match mut_ty.ty.node {
TyKind::Path(ref qpath) => {
let hir_id = cx.tcx.hir().node_to_hir_id(mut_ty.ty.id);
span_lint_and_sugg(
cx,
BORROWED_BOX,
- ast_ty.span,
+ hir_ty.span,
"you seem to be trying to use `&Box<T>`. Consider using just `&T`",
"try",
format!(
"creating a let binding to a value of unit type, which usually can't be used afterwards"
}
-fn check_let_unit(cx: &LateContext<'_, '_>, decl: &Decl) {
- if let DeclKind::Local(ref local) = decl.node {
- if is_unit(cx.tables.pat_ty(&local.pat)) {
- if in_external_macro(cx.sess(), decl.span) || in_macro(local.pat.span) {
- return;
- }
- if higher::is_from_for_desugar(decl) {
- return;
- }
- span_lint(
- cx,
- LET_UNIT_VALUE,
- decl.span,
- &format!(
- "this let-binding has unit value. Consider omitting `let {} =`",
- snippet(cx, local.pat.span, "..")
- ),
- );
- }
- }
-}
-
impl LintPass for LetPass {
fn get_lints(&self) -> LintArray {
lint_array!(LET_UNIT_VALUE)
}
+
+ fn name(&self) -> &'static str {
+ "LetUnitValue"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetPass {
- fn check_decl(&mut self, cx: &LateContext<'a, 'tcx>, decl: &'tcx Decl) {
- check_let_unit(cx, decl)
+ fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt) {
+ if let StmtKind::Local(ref local) = stmt.node {
+ if is_unit(cx.tables.pat_ty(&local.pat)) {
+ if in_external_macro(cx.sess(), stmt.span) || in_macro(local.pat.span) {
+ return;
+ }
+ if higher::is_from_for_desugar(local) {
+ return;
+ }
+ span_lint(
+ cx,
+ LET_UNIT_VALUE,
+ stmt.span,
+ &format!(
+ "this let-binding has unit value. Consider omitting `let {} =`",
+ snippet(cx, local.pat.span, "..")
+ ),
+ );
+ }
+ }
}
}
fn get_lints(&self) -> LintArray {
lint_array!(UNIT_CMP)
}
+
+ fn name(&self) -> &'static str {
+ "UnicCmp"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnitCmp {
fn get_lints(&self) -> LintArray {
lint_array!(UNIT_ARG)
}
+
+ fn name(&self) -> &'static str {
+ "UnitArg"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnitArg {
if in_macro(expr.span) {
return;
}
+
+ // apparently stuff in the desugaring of `?` can trigger this
+ // so check for that here
+ // only the calls to `Try::from_error` is marked as desugared,
+ // so we need to check both the current Expr and its parent.
+ if is_questionmark_desugar_marked_call(expr) {
+ return;
+ }
+ if_chain! {
+ let map = &cx.tcx.hir();
+ let opt_parent_node = map.find(map.get_parent_node(expr.id));
+ if let Some(hir::Node::Expr(parent_expr)) = opt_parent_node;
+ if is_questionmark_desugar_marked_call(parent_expr);
+ then {
+ return;
+ }
+ }
+
match expr.node {
ExprKind::Call(_, ref args) | ExprKind::MethodCall(_, _, ref args) => {
for arg in args {
if is_unit(cx.tables.expr_ty(arg)) && !is_unit_literal(arg) {
- let map = &cx.tcx.hir();
- // apparently stuff in the desugaring of `?` can trigger this
- // so check for that here
- // only the calls to `Try::from_error` is marked as desugared,
- // so we need to check both the current Expr and its parent.
- if !is_questionmark_desugar_marked_call(expr) {
- if_chain! {
- let opt_parent_node = map.find(map.get_parent_node(expr.id));
- if let Some(hir::Node::Expr(parent_expr)) = opt_parent_node;
- if is_questionmark_desugar_marked_call(parent_expr);
- then {}
- else {
- // `expr` and `parent_expr` where _both_ not from
- // desugaring `?`, so lint
- span_lint_and_sugg(
- cx,
- UNIT_ARG,
- arg.span,
- "passing a unit value to a function",
- "if you intended to pass a unit value, use a unit literal instead",
- "()".to_string(),
- Applicability::MachineApplicable,
- );
- }
+ if let ExprKind::Match(.., match_source) = &arg.node {
+ if *match_source == MatchSource::TryDesugar {
+ continue;
}
}
+
+ span_lint_and_sugg(
+ cx,
+ UNIT_ARG,
+ arg.span,
+ "passing a unit value to a function",
+ "if you intended to pass a unit value, use a unit literal instead",
+ "()".to_string(),
+ Applicability::MachineApplicable,
+ );
}
}
},
FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
)
}
+
+ fn name(&self) -> &'static str {
+ "Casts"
+ }
}
// Check if the given type is either `core::ffi::c_void` or
fn get_lints(&self) -> LintArray {
lint_array!(TYPE_COMPLEXITY)
}
+
+ fn name(&self) -> &'static str {
+ "TypeComplexityPass"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TypeComplexityPass {
self.check_fndecl(cx, decl);
}
- fn check_struct_field(&mut self, cx: &LateContext<'a, 'tcx>, field: &'tcx StructField) {
+ fn check_struct_field(&mut self, cx: &LateContext<'a, 'tcx>, field: &'tcx hir::StructField) {
// enum variants are also struct fields now
self.check_type(cx, &field.ty);
}
fn get_lints(&self) -> LintArray {
lint_array!(CHAR_LIT_AS_U8)
}
+
+ fn name(&self) -> &'static str {
+ "CharLiteralAsU8"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CharLitAsU8 {
fn get_lints(&self) -> LintArray {
lint_array!(ABSURD_EXTREME_COMPARISONS)
}
+
+ fn name(&self) -> &'static str {
+ "AbsurdExtremeComparisons"
+ }
}
enum ExtremeType {
fn get_lints(&self) -> LintArray {
lint_array!(INVALID_UPCAST_COMPARISONS)
}
+
+ fn name(&self) -> &'static str {
+ "InvalidUpcastComparisons"
+ }
}
#[derive(Copy, Clone, Debug, Eq)]
fn get_lints(&self) -> LintArray {
lint_array!(IMPLICIT_HASHER)
}
+
+ fn name(&self) -> &'static str {
+ "ImplicitHasher"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImplicitHasher {
NestedVisitorMap::OnlyBodies(&self.cx.tcx.hir())
}
}
+
+/// **What it does:** Checks for casts of `&T` to `&mut T` anywhere in the code.
+///
+/// **Why is this bad?** It’s basically guaranteed to be undefined behaviour.
+/// `UnsafeCell` is the only way to obtain aliasable data that is considered
+/// mutable.
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// fn x(r: &i32) {
+/// unsafe {
+/// *(r as *const _ as *mut _) += 1;
+/// }
+/// }
+/// ```
+///
+/// Instead consider using interior mutability types.
+///
+/// ```rust
+/// fn x(r: &UnsafeCell<i32>) {
+/// unsafe {
+/// *r.get() += 1;
+/// }
+/// }
+/// ```
+declare_clippy_lint! {
+ pub CAST_REF_TO_MUT,
+ correctness,
+ "a cast of reference to a mutable pointer"
+}
+
+pub struct RefToMut;
+
+impl LintPass for RefToMut {
+ fn get_lints(&self) -> LintArray {
+ lint_array!(CAST_REF_TO_MUT)
+ }
+
+ fn name(&self) -> &'static str {
+ "RefToMut"
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for RefToMut {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+ if_chain! {
+ if let ExprKind::Unary(UnOp::UnDeref, e) = &expr.node;
+ if let ExprKind::Cast(e, t) = &e.node;
+ if let TyKind::Ptr(MutTy { mutbl: Mutability::MutMutable, .. }) = t.node;
+ if let ExprKind::Cast(e, t) = &e.node;
+ if let TyKind::Ptr(MutTy { mutbl: Mutability::MutImmutable, .. }) = t.node;
+ if let ty::Ref(..) = cx.tables.node_id_to_type(e.hir_id).sty;
+ then {
+ span_lint(
+ cx,
+ CAST_REF_TO_MUT,
+ expr.span,
+ "casting &T to &mut T may cause undefined behaviour, consider instead using an UnsafeCell",
+ );
+ }
+ }
+ }
+}