1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
15 use syntax::codemap::Span;
17 /// **What it does:** it lints if an exported function, method, trait method with default impl,
18 /// or trait method impl is not `#[inline]`.
20 /// **Why is this bad?** In general, it is not. Functions can be inlined across
21 /// crates when that's profitable as long as any form of LTO is used. When LTO is disabled,
22 /// functions that are not `#[inline]` cannot be inlined across crates. Certain types of crates
23 /// might intend for most of the methods in their public API to be able to be inlined across
24 /// crates even when LTO is disabled. For these types of crates, enabling this lint might make sense.
25 /// It allows the crate to require all exported methods to be `#[inline]` by default, and then opt
26 /// out for specific methods where this might not make sense.
28 /// **Known problems:** None.
32 /// pub fn foo() {} // missing #[inline]
34 /// #[inline] pub fn bar() {} // ok
35 /// #[inline(always)] pub fn baz() {} // ok
39 /// fn def_bar() {} // missing #[inline]
44 /// fn priv() {} // ok
47 /// impl Bar for Baz {
48 /// fn bar() {} // ok - Baz is not exported
51 /// pub struct PubBaz;
53 /// fn priv() {} // ok
54 /// pub not_ptriv() {} // missing #[inline]
57 /// impl Bar for PubBaz {
58 /// fn bar() {} // missing #[inline]
59 /// fn def_bar() {} // missing #[inline]
62 declare_clippy_lint! {
63 pub MISSING_INLINE_IN_PUBLIC_ITEMS,
65 "detects missing #[inline] attribute for public callables (functions, trait methods, methods...)"
68 pub struct MissingInline;
71 fn check_missing_inline_attrs(&self, cx: &LateContext,
72 attrs: &[ast::Attribute], sp: Span, desc: &'static str) {
73 let has_inline = attrs
75 .any(|a| a.name() == "inline" );
78 MISSING_INLINE_IN_PUBLIC_ITEMS,
80 &format!("missing `#[inline]` for {}", desc),
86 impl LintPass for MissingInline {
87 fn get_lints(&self) -> LintArray {
88 lint_array![MISSING_INLINE_IN_PUBLIC_ITEMS]
92 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingInline {
93 fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, it: &'tcx hir::Item) {
94 if !cx.access_levels.is_exported(it.id) {
100 if it.name == "main" {
101 let def_id = cx.tcx.hir.local_def_id(it.id);
102 let def_key = cx.tcx.hir.def_key(def_id);
103 if def_key.parent == Some(hir::def_id::CRATE_DEF_INDEX) {
107 let desc = "a function";
108 self.check_missing_inline_attrs(cx, &it.attrs, it.span, desc);
110 hir::ItemTrait(ref _is_auto, ref _unsafe, ref _generics,
111 ref _bounds, ref trait_items) => {
112 // note: we need to check if the trait is exported so we can't use
113 // `LateLintPass::check_trait_item` here.
114 for tit in trait_items {
115 let tit_ = cx.tcx.hir.trait_item(tit.id);
117 hir::TraitItemKind::Const(..) |
118 hir::TraitItemKind::Type(..) => {},
119 hir::TraitItemKind::Method(..) => {
120 if tit.defaultness.has_value() {
121 // trait method with default body needs inline in case
122 // an impl is not provided
123 let desc = "a default trait method";
124 let item = cx.tcx.hir.expect_trait_item(tit.id.node_id);
125 self.check_missing_inline_attrs(cx, &item.attrs,
135 hir::ItemStatic(..) |
136 hir::ItemStruct(..) |
137 hir::ItemTraitAlias(..) |
138 hir::ItemGlobalAsm(..) |
141 hir::ItemExistential(..) |
142 hir::ItemExternCrate(..) |
143 hir::ItemForeignMod(..) |
145 hir::ItemUse(..) => {},
149 fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx hir::ImplItem) {
150 use rustc::ty::{TraitContainer, ImplContainer};
152 // If the item being implemented is not exported, then we don't need #[inline]
153 if !cx.access_levels.is_exported(impl_item.id) {
157 let desc = match impl_item.node {
158 hir::ImplItemKind::Method(..) => "a method",
159 hir::ImplItemKind::Const(..) |
160 hir::ImplItemKind::Type(_) => return,
163 let def_id = cx.tcx.hir.local_def_id(impl_item.id);
164 match cx.tcx.associated_item(def_id).container {
165 TraitContainer(cid) => {
166 if let Some(n) = cx.tcx.hir.as_local_node_id(cid) {
167 if !cx.access_levels.is_exported(n) {
168 // If a trait is being implemented for an item, and the
169 // trait is not exported, we don't need #[inline]
174 ImplContainer(cid) => {
175 if cx.tcx.impl_trait_ref(cid).is_some() {
176 let trait_ref = cx.tcx.impl_trait_ref(cid).unwrap();
177 if let Some(n) = cx.tcx.hir.as_local_node_id(trait_ref.def_id) {
178 if !cx.access_levels.is_exported(n) {
179 // If a trait is being implemented for an item, and the
180 // trait is not exported, we don't need #[inline]
188 self.check_missing_inline_attrs(cx, &impl_item.attrs, impl_item.span, desc);