1 // Copyright 2012 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.
11 // Detecting language items.
13 // Language items are items that represent concepts intrinsic to the language
14 // itself. Examples are:
16 // * Traits that specify "kinds"; e.g. "Sync", "Send".
18 // * Traits that represent operators; e.g. "Add", "Sub", "Index".
20 // * Functions called by the compiler itself.
22 pub use self::LangItem::*;
25 use metadata::csearch::each_lang_item;
26 use middle::def_id::DefId;
28 use middle::weak_lang_items;
29 use util::nodemap::FnvHashMap;
31 use rustc_front::attr::AttrMetaMethods;
32 use syntax::codemap::{DUMMY_SP, Span};
33 use syntax::parse::token::InternedString;
34 use rustc_front::visit::Visitor;
35 use rustc_front::visit;
38 use std::iter::Enumerate;
41 // The actual lang items defined come at the end of this file in one handy table.
42 // So you probably just want to nip down to the end.
43 macro_rules! lets_do_this {
45 $( $variant:ident, $name:expr, $method:ident; )*
50 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
56 pub struct LanguageItems {
57 pub items: Vec<Option<DefId>>,
58 pub missing: Vec<LangItem>,
62 pub fn new() -> LanguageItems {
63 fn foo(_: LangItem) -> Option<DefId> { None }
66 items: vec!($(foo($variant)),*),
71 pub fn items<'a>(&'a self) -> Enumerate<slice::Iter<'a, Option<DefId>>> {
72 self.items.iter().enumerate()
75 pub fn item_name(index: usize) -> &'static str {
76 let item: Option<LangItem> = LangItem::from_u32(index as u32);
78 $( Some($variant) => $name, )*
83 pub fn require(&self, it: LangItem) -> Result<DefId, String> {
84 match self.items[it as usize] {
87 Err(format!("requires `{}` lang_item",
88 LanguageItems::item_name(it as usize)))
93 pub fn require_owned_box(&self) -> Result<DefId, String> {
94 self.require(OwnedBoxLangItem)
97 pub fn from_builtin_kind(&self, bound: ty::BuiltinBound)
98 -> Result<DefId, String>
101 ty::BoundSend => self.require(SendTraitLangItem),
102 ty::BoundSized => self.require(SizedTraitLangItem),
103 ty::BoundCopy => self.require(CopyTraitLangItem),
104 ty::BoundSync => self.require(SyncTraitLangItem),
108 pub fn to_builtin_kind(&self, id: DefId) -> Option<ty::BuiltinBound> {
109 if Some(id) == self.send_trait() {
111 } else if Some(id) == self.sized_trait() {
113 } else if Some(id) == self.copy_trait() {
115 } else if Some(id) == self.sync_trait() {
122 pub fn fn_trait_kind(&self, id: DefId) -> Option<ty::ClosureKind> {
124 (self.fn_trait(), ty::FnClosureKind),
125 (self.fn_mut_trait(), ty::FnMutClosureKind),
126 (self.fn_once_trait(), ty::FnOnceClosureKind),
129 for &(opt_def_id, kind) in &def_id_kinds {
130 if Some(id) == opt_def_id {
140 pub fn $method(&self) -> Option<DefId> {
141 self.items[$variant as usize]
146 struct LanguageItemCollector<'a> {
147 items: LanguageItems,
149 session: &'a Session,
151 item_refs: FnvHashMap<&'static str, usize>,
154 impl<'a, 'v> Visitor<'v> for LanguageItemCollector<'a> {
155 fn visit_item(&mut self, item: &hir::Item) {
156 if let Some(value) = extract(&item.attrs) {
157 let item_index = self.item_refs.get(&value[..]).cloned();
159 if let Some(item_index) = item_index {
160 self.collect_item(item_index, DefId::local(item.id), item.span)
164 visit::walk_item(self, item);
168 impl<'a> LanguageItemCollector<'a> {
169 pub fn new(session: &'a Session) -> LanguageItemCollector<'a> {
170 let mut item_refs = FnvHashMap();
172 $( item_refs.insert($name, $variant as usize); )*
174 LanguageItemCollector {
176 items: LanguageItems::new(),
181 pub fn collect_item(&mut self, item_index: usize,
182 item_def_id: DefId, span: Span) {
183 // Check for duplicates.
184 match self.items.items[item_index] {
185 Some(original_def_id) if original_def_id != item_def_id => {
186 span_err!(self.session, span, E0152,
187 "duplicate entry for `{}`", LanguageItems::item_name(item_index));
195 self.items.items[item_index] = Some(item_def_id);
198 pub fn collect_local_language_items(&mut self, krate: &hir::Crate) {
199 visit::walk_crate(self, krate);
202 pub fn collect_external_language_items(&mut self) {
203 let crate_store = &self.session.cstore;
204 crate_store.iter_crate_data(|crate_number, _crate_metadata| {
205 each_lang_item(crate_store, crate_number, |node_id, item_index| {
206 let def_id = DefId { krate: crate_number, node: node_id };
207 self.collect_item(item_index, def_id, DUMMY_SP);
213 pub fn collect(&mut self, krate: &hir::Crate) {
214 self.collect_local_language_items(krate);
215 self.collect_external_language_items();
219 pub fn extract(attrs: &[hir::Attribute]) -> Option<InternedString> {
220 for attribute in attrs {
221 match attribute.value_str() {
222 Some(ref value) if attribute.check_name("lang") => {
223 return Some(value.clone());
232 pub fn collect_language_items(krate: &hir::Crate,
233 session: &Session) -> LanguageItems {
234 let mut collector = LanguageItemCollector::new(session);
235 collector.collect(krate);
236 let LanguageItemCollector { mut items, .. } = collector;
237 weak_lang_items::check_crate(krate, session, &mut items);
238 session.abort_if_errors();
247 // Variant name, Name, Method name;
248 CharImplItem, "char", char_impl;
249 StrImplItem, "str", str_impl;
250 SliceImplItem, "slice", slice_impl;
251 ConstPtrImplItem, "const_ptr", const_ptr_impl;
252 MutPtrImplItem, "mut_ptr", mut_ptr_impl;
253 I8ImplItem, "i8", i8_impl;
254 I16ImplItem, "i16", i16_impl;
255 I32ImplItem, "i32", i32_impl;
256 I64ImplItem, "i64", i64_impl;
257 IsizeImplItem, "isize", isize_impl;
258 U8ImplItem, "u8", u8_impl;
259 U16ImplItem, "u16", u16_impl;
260 U32ImplItem, "u32", u32_impl;
261 U64ImplItem, "u64", u64_impl;
262 UsizeImplItem, "usize", usize_impl;
263 F32ImplItem, "f32", f32_impl;
264 F64ImplItem, "f64", f64_impl;
266 SendTraitLangItem, "send", send_trait;
267 SizedTraitLangItem, "sized", sized_trait;
268 UnsizeTraitLangItem, "unsize", unsize_trait;
269 CopyTraitLangItem, "copy", copy_trait;
270 SyncTraitLangItem, "sync", sync_trait;
272 DropTraitLangItem, "drop", drop_trait;
274 CoerceUnsizedTraitLangItem, "coerce_unsized", coerce_unsized_trait;
276 AddTraitLangItem, "add", add_trait;
277 SubTraitLangItem, "sub", sub_trait;
278 MulTraitLangItem, "mul", mul_trait;
279 DivTraitLangItem, "div", div_trait;
280 RemTraitLangItem, "rem", rem_trait;
281 NegTraitLangItem, "neg", neg_trait;
282 NotTraitLangItem, "not", not_trait;
283 BitXorTraitLangItem, "bitxor", bitxor_trait;
284 BitAndTraitLangItem, "bitand", bitand_trait;
285 BitOrTraitLangItem, "bitor", bitor_trait;
286 ShlTraitLangItem, "shl", shl_trait;
287 ShrTraitLangItem, "shr", shr_trait;
288 IndexTraitLangItem, "index", index_trait;
289 IndexMutTraitLangItem, "index_mut", index_mut_trait;
290 RangeStructLangItem, "range", range_struct;
291 RangeFromStructLangItem, "range_from", range_from_struct;
292 RangeToStructLangItem, "range_to", range_to_struct;
293 RangeFullStructLangItem, "range_full", range_full_struct;
295 UnsafeCellTypeLangItem, "unsafe_cell", unsafe_cell_type;
297 DerefTraitLangItem, "deref", deref_trait;
298 DerefMutTraitLangItem, "deref_mut", deref_mut_trait;
300 FnTraitLangItem, "fn", fn_trait;
301 FnMutTraitLangItem, "fn_mut", fn_mut_trait;
302 FnOnceTraitLangItem, "fn_once", fn_once_trait;
304 EqTraitLangItem, "eq", eq_trait;
305 OrdTraitLangItem, "ord", ord_trait;
307 StrEqFnLangItem, "str_eq", str_eq_fn;
309 // A number of panic-related lang items. The `panic` item corresponds to
310 // divide-by-zero and various panic cases with `match`. The
311 // `panic_bounds_check` item is for indexing arrays.
313 // The `begin_unwind` lang item has a predefined symbol name and is sort of
314 // a "weak lang item" in the sense that a crate is not required to have it
315 // defined to use it, but a final product is required to define it
316 // somewhere. Additionally, there are restrictions on crates that use a weak
317 // lang item, but do not have it defined.
318 PanicFnLangItem, "panic", panic_fn;
319 PanicBoundsCheckFnLangItem, "panic_bounds_check", panic_bounds_check_fn;
320 PanicFmtLangItem, "panic_fmt", panic_fmt;
322 ExchangeMallocFnLangItem, "exchange_malloc", exchange_malloc_fn;
323 ExchangeFreeFnLangItem, "exchange_free", exchange_free_fn;
324 StrDupUniqFnLangItem, "strdup_uniq", strdup_uniq_fn;
326 StartFnLangItem, "start", start_fn;
328 EhPersonalityLangItem, "eh_personality", eh_personality;
329 EhPersonalityCatchLangItem, "eh_personality_catch", eh_personality_catch;
330 EhUnwindResumeLangItem, "eh_unwind_resume", eh_unwind_resume;
331 MSVCTryFilterLangItem, "msvc_try_filter", msvc_try_filter;
333 ExchangeHeapLangItem, "exchange_heap", exchange_heap;
334 OwnedBoxLangItem, "owned_box", owned_box;
336 PhantomDataItem, "phantom_data", phantom_data;
339 CovariantTypeItem, "covariant_type", covariant_type;
340 ContravariantTypeItem, "contravariant_type", contravariant_type;
341 InvariantTypeItem, "invariant_type", invariant_type;
342 CovariantLifetimeItem, "covariant_lifetime", covariant_lifetime;
343 ContravariantLifetimeItem, "contravariant_lifetime", contravariant_lifetime;
344 InvariantLifetimeItem, "invariant_lifetime", invariant_lifetime;
346 NoCopyItem, "no_copy_bound", no_copy_bound;
348 NonZeroItem, "non_zero", non_zero;
350 DebugTraitLangItem, "debug_trait", debug_trait;