|
| 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. |
| 4 | +// |
| 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. |
| 10 | +// |
| 11 | + |
| 12 | +use rustc::hir; |
| 13 | +use rustc::lint::*; |
| 14 | +use syntax::ast; |
| 15 | +use syntax::codemap::Span; |
| 16 | + |
| 17 | +/// **What it does:** it lints if an exported function, method, trait method with default impl, |
| 18 | +/// or trait method impl is not `#[inline]`. |
| 19 | +/// |
| 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. |
| 27 | +/// |
| 28 | +/// **Known problems:** None. |
| 29 | +declare_clippy_lint! { |
| 30 | + pub MISSING_INLINE_IN_PUBLIC_ITEMS, |
| 31 | + restriction, |
| 32 | + "detects missing #[inline] attribute for public callables (functions, trait methods, methods...)" |
| 33 | +} |
| 34 | + |
| 35 | +pub struct MissingInline {} |
| 36 | + |
| 37 | +impl ::std::default::Default for MissingInline { |
| 38 | + fn default() -> Self { |
| 39 | + Self::new() |
| 40 | + } |
| 41 | +} |
| 42 | + |
| 43 | +impl MissingInline { |
| 44 | + pub fn new() -> Self { |
| 45 | + Self {} |
| 46 | + } |
| 47 | + |
| 48 | + fn check_missing_inline_attrs(&self, cx: &LateContext, |
| 49 | + attrs: &[ast::Attribute], sp: Span, desc: &'static str) { |
| 50 | + // If we're building a test harness, FIXME: is this relevant? |
| 51 | + // if cx.sess().opts.test { |
| 52 | + // return; |
| 53 | + // } |
| 54 | + |
| 55 | + let has_inline = attrs |
| 56 | + .iter() |
| 57 | + .any(|a| a.name() == "inline" ); |
| 58 | + if !has_inline { |
| 59 | + cx.span_lint( |
| 60 | + MISSING_INLINE_IN_PUBLIC_ITEMS, |
| 61 | + sp, |
| 62 | + &format!("missing `#[inline]` for {}", desc), |
| 63 | + ); |
| 64 | + } |
| 65 | + } |
| 66 | +} |
| 67 | + |
| 68 | +impl LintPass for MissingInline { |
| 69 | + fn get_lints(&self) -> LintArray { |
| 70 | + lint_array![MISSING_INLINE_IN_PUBLIC_ITEMS] |
| 71 | + } |
| 72 | +} |
| 73 | + |
| 74 | +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingInline { |
| 75 | + fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, it: &'tcx hir::Item) { |
| 76 | + if !cx.access_levels.is_exported(it.id) { |
| 77 | + return; |
| 78 | + } |
| 79 | + match it.node { |
| 80 | + hir::ItemFn(..) => { |
| 81 | + // ignore main() |
| 82 | + if it.name == "main" { |
| 83 | + let def_id = cx.tcx.hir.local_def_id(it.id); |
| 84 | + let def_key = cx.tcx.hir.def_key(def_id); |
| 85 | + if def_key.parent == Some(hir::def_id::CRATE_DEF_INDEX) { |
| 86 | + return; |
| 87 | + } |
| 88 | + } |
| 89 | + let desc = "a function"; |
| 90 | + self.check_missing_inline_attrs(cx, &it.attrs, it.span, desc); |
| 91 | + }, |
| 92 | + hir::ItemTrait(ref _is_auto, ref _unsafe, ref _generics, |
| 93 | + ref _bounds, ref trait_items) => { |
| 94 | + for tit in trait_items { |
| 95 | + let tit_ = cx.tcx.hir.trait_item(tit.id); |
| 96 | + match tit_.node { |
| 97 | + hir::TraitItemKind::Const(..) | |
| 98 | + hir::TraitItemKind::Type(..) => {}, |
| 99 | + hir::TraitItemKind::Method(..) => { |
| 100 | + if tit.defaultness.has_value() { |
| 101 | + // trait method with default body needs inline in case |
| 102 | + // an impl is not provided |
| 103 | + let desc = "a default trait method"; |
| 104 | + let item = cx.tcx.hir.expect_trait_item(tit.id.node_id); |
| 105 | + self.check_missing_inline_attrs(cx, &item.attrs, |
| 106 | + item.span, desc); |
| 107 | + } |
| 108 | + }, |
| 109 | + } |
| 110 | + } |
| 111 | + } |
| 112 | + hir::ItemConst(..) | |
| 113 | + hir::ItemEnum(..) | |
| 114 | + hir::ItemMod(..) | |
| 115 | + hir::ItemStatic(..) | |
| 116 | + hir::ItemStruct(..) | |
| 117 | + hir::ItemTraitAlias(..) | |
| 118 | + hir::ItemGlobalAsm(..) | |
| 119 | + hir::ItemTy(..) | |
| 120 | + hir::ItemUnion(..) | |
| 121 | + hir::ItemExistential(..) | |
| 122 | + hir::ItemExternCrate(..) | |
| 123 | + hir::ItemForeignMod(..) | |
| 124 | + hir::ItemImpl(..) | |
| 125 | + hir::ItemUse(..) => {}, |
| 126 | + }; |
| 127 | + } |
| 128 | + |
| 129 | + fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx hir::ImplItem) { |
| 130 | + use rustc::ty::{TraitContainer, ImplContainer}; |
| 131 | + |
| 132 | + // If the item being implemented is not exported, then we don't need #[inline] |
| 133 | + if !cx.access_levels.is_exported(impl_item.id) { |
| 134 | + return; |
| 135 | + } |
| 136 | + |
| 137 | + let def_id = cx.tcx.hir.local_def_id(impl_item.id); |
| 138 | + match cx.tcx.associated_item(def_id).container { |
| 139 | + TraitContainer(cid) => { |
| 140 | + let n = cx.tcx.hir.as_local_node_id(cid); |
| 141 | + if n.is_some() { |
| 142 | + if !cx.access_levels.is_exported(n.unwrap()) { |
| 143 | + // If a trait is being implemented for an item, and the |
| 144 | + // trait is not exported, we don't need #[inline] |
| 145 | + return; |
| 146 | + } |
| 147 | + } |
| 148 | + }, |
| 149 | + ImplContainer(cid) => { |
| 150 | + if cx.tcx.impl_trait_ref(cid).is_some() { |
| 151 | + let trait_ref = cx.tcx.impl_trait_ref(cid).unwrap(); |
| 152 | + let n = cx.tcx.hir.as_local_node_id(trait_ref.def_id); |
| 153 | + if n.is_some() { |
| 154 | + if !cx.access_levels.is_exported(n.unwrap()) { |
| 155 | + // If a trait is being implemented for an item, and the |
| 156 | + // trait is not exported, we don't need #[inline] |
| 157 | + return; |
| 158 | + } |
| 159 | + } |
| 160 | + } |
| 161 | + }, |
| 162 | + } |
| 163 | + |
| 164 | + let desc = match impl_item.node { |
| 165 | + hir::ImplItemKind::Method(..) => "a method", |
| 166 | + hir::ImplItemKind::Const(..) | |
| 167 | + hir::ImplItemKind::Type(_) => return, |
| 168 | + }; |
| 169 | + self.check_missing_inline_attrs(cx, &impl_item.attrs, impl_item.span, desc); |
| 170 | + } |
| 171 | +} |
0 commit comments