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.
23 use driver::session::Session;
24 use metadata::csearch::each_lang_item;
26 use middle::weak_lang_items;
28 use syntax::ast_util::local_def;
29 use syntax::attr::AttrMetaMethods;
30 use syntax::codemap::{DUMMY_SP, Span};
31 use syntax::parse::token::InternedString;
32 use syntax::visit::Visitor;
35 use std::collections::HashMap;
36 use std::iter::Enumerate;
39 // The actual lang items defined come at the end of this file in one handy table.
40 // So you probably just want to nip down to the end.
41 macro_rules! lets_do_this {
43 $( $variant:ident, $name:expr, $method:ident; )*
46 #[deriving(FromPrimitive, PartialEq, Eq, Hash)]
51 pub struct LanguageItems {
52 pub items: Vec<Option<ast::DefId>>,
53 pub missing: Vec<LangItem>,
57 pub fn new() -> LanguageItems {
58 fn foo(_: LangItem) -> Option<ast::DefId> { None }
61 items: vec!($(foo($variant)),*),
66 pub fn items<'a>(&'a self) -> Enumerate<slice::Items<'a, Option<ast::DefId>>> {
67 self.items.iter().enumerate()
70 pub fn item_name(index: uint) -> &'static str {
71 let item: Option<LangItem> = FromPrimitive::from_uint(index);
73 $( Some($variant) => $name, )*
78 pub fn require(&self, it: LangItem) -> Result<ast::DefId, String> {
79 match self.items.get(it as uint) {
82 Err(format!("requires `{}` lang_item",
83 LanguageItems::item_name(it as uint)))
88 pub fn from_builtin_kind(&self, bound: ty::BuiltinBound)
89 -> Result<ast::DefId, String>
92 ty::BoundSend => self.require(SendTraitLangItem),
93 ty::BoundSized => self.require(SizedTraitLangItem),
94 ty::BoundCopy => self.require(CopyTraitLangItem),
95 ty::BoundSync => self.require(SyncTraitLangItem),
99 pub fn to_builtin_kind(&self, id: ast::DefId) -> Option<ty::BuiltinBound> {
100 if Some(id) == self.send_trait() {
102 } else if Some(id) == self.sized_trait() {
104 } else if Some(id) == self.copy_trait() {
106 } else if Some(id) == self.sync_trait() {
115 pub fn $method(&self) -> Option<ast::DefId> {
116 *self.items.get($variant as uint)
121 struct LanguageItemCollector<'a> {
122 items: LanguageItems,
124 session: &'a Session,
126 item_refs: HashMap<&'static str, uint>,
129 impl<'a, 'v> Visitor<'v> for LanguageItemCollector<'a> {
130 fn visit_item(&mut self, item: &ast::Item) {
131 match extract(item.attrs.as_slice()) {
133 let item_index = self.item_refs.find_equiv(&value).map(|x| *x);
136 Some(item_index) => {
137 self.collect_item(item_index, local_def(item.id), item.span)
145 visit::walk_item(self, item);
149 impl<'a> LanguageItemCollector<'a> {
150 pub fn new(session: &'a Session) -> LanguageItemCollector<'a> {
151 let mut item_refs = HashMap::new();
153 $( item_refs.insert($name, $variant as uint); )*
155 LanguageItemCollector {
157 items: LanguageItems::new(),
162 pub fn collect_item(&mut self, item_index: uint,
163 item_def_id: ast::DefId, span: Span) {
164 // Check for duplicates.
165 match self.items.items.get(item_index) {
166 &Some(original_def_id) if original_def_id != item_def_id => {
167 span_err!(self.session, span, E0152,
168 "duplicate entry for `{}`", LanguageItems::item_name(item_index));
170 &Some(_) | &None => {
176 *self.items.items.get_mut(item_index) = Some(item_def_id);
179 pub fn collect_local_language_items(&mut self, krate: &ast::Crate) {
180 visit::walk_crate(self, krate);
183 pub fn collect_external_language_items(&mut self) {
184 let crate_store = &self.session.cstore;
185 crate_store.iter_crate_data(|crate_number, _crate_metadata| {
186 each_lang_item(crate_store, crate_number, |node_id, item_index| {
187 let def_id = ast::DefId { krate: crate_number, node: node_id };
188 self.collect_item(item_index, def_id, DUMMY_SP);
194 pub fn collect(&mut self, krate: &ast::Crate) {
195 self.collect_local_language_items(krate);
196 self.collect_external_language_items();
200 pub fn extract(attrs: &[ast::Attribute]) -> Option<InternedString> {
201 for attribute in attrs.iter() {
202 match attribute.value_str() {
203 Some(ref value) if attribute.check_name("lang") => {
204 return Some(value.clone());
213 pub fn collect_language_items(krate: &ast::Crate,
214 session: &Session) -> LanguageItems {
215 let mut collector = LanguageItemCollector::new(session);
216 collector.collect(krate);
217 let LanguageItemCollector { mut items, .. } = collector;
218 weak_lang_items::check_crate(krate, session, &mut items);
219 session.abort_if_errors();
228 // Variant name, Name, Method name;
229 SendTraitLangItem, "send", send_trait;
230 SizedTraitLangItem, "sized", sized_trait;
231 CopyTraitLangItem, "copy", copy_trait;
232 SyncTraitLangItem, "sync", sync_trait;
234 DropTraitLangItem, "drop", drop_trait;
236 AddTraitLangItem, "add", add_trait;
237 SubTraitLangItem, "sub", sub_trait;
238 MulTraitLangItem, "mul", mul_trait;
239 DivTraitLangItem, "div", div_trait;
240 RemTraitLangItem, "rem", rem_trait;
241 NegTraitLangItem, "neg", neg_trait;
242 NotTraitLangItem, "not", not_trait;
243 BitXorTraitLangItem, "bitxor", bitxor_trait;
244 BitAndTraitLangItem, "bitand", bitand_trait;
245 BitOrTraitLangItem, "bitor", bitor_trait;
246 ShlTraitLangItem, "shl", shl_trait;
247 ShrTraitLangItem, "shr", shr_trait;
248 IndexTraitLangItem, "index", index_trait;
249 IndexMutTraitLangItem, "index_mut", index_mut_trait;
250 SliceTraitLangItem, "slice", slice_trait;
251 SliceMutTraitLangItem, "slice_mut", slice_mut_trait;
253 UnsafeTypeLangItem, "unsafe", unsafe_type;
255 DerefTraitLangItem, "deref", deref_trait;
256 DerefMutTraitLangItem, "deref_mut", deref_mut_trait;
258 FnTraitLangItem, "fn", fn_trait;
259 FnMutTraitLangItem, "fn_mut", fn_mut_trait;
260 FnOnceTraitLangItem, "fn_once", fn_once_trait;
262 EqTraitLangItem, "eq", eq_trait;
263 OrdTraitLangItem, "ord", ord_trait;
265 StrEqFnLangItem, "str_eq", str_eq_fn;
267 // A number of failure-related lang items. The `fail_` item corresponds to
268 // divide-by-zero and various failure cases with `match`. The
269 // `fail_bounds_check` item is for indexing arrays.
271 // The `begin_unwind` lang item has a predefined symbol name and is sort of
272 // a "weak lang item" in the sense that a crate is not required to have it
273 // defined to use it, but a final product is required to define it
274 // somewhere. Additionally, there are restrictions on crates that use a weak
275 // lang item, but do not have it defined.
276 FailFnLangItem, "fail_", fail_fn;
277 FailBoundsCheckFnLangItem, "fail_bounds_check", fail_bounds_check_fn;
278 BeginUnwindLangItem, "begin_unwind", begin_unwind;
280 ExchangeMallocFnLangItem, "exchange_malloc", exchange_malloc_fn;
281 ExchangeFreeFnLangItem, "exchange_free", exchange_free_fn;
282 MallocFnLangItem, "malloc", malloc_fn;
283 FreeFnLangItem, "free", free_fn;
284 StrDupUniqFnLangItem, "strdup_uniq", strdup_uniq_fn;
286 StartFnLangItem, "start", start_fn;
288 TyDescStructLangItem, "ty_desc", ty_desc;
289 TyVisitorTraitLangItem, "ty_visitor", ty_visitor;
290 OpaqueStructLangItem, "opaque", opaque;
292 TypeIdLangItem, "type_id", type_id;
294 EhPersonalityLangItem, "eh_personality", eh_personality;
296 ManagedHeapLangItem, "managed_heap", managed_heap;
297 ExchangeHeapLangItem, "exchange_heap", exchange_heap;
298 GcLangItem, "gc", gc;
299 OwnedBoxLangItem, "owned_box", owned_box;
301 CovariantTypeItem, "covariant_type", covariant_type;
302 ContravariantTypeItem, "contravariant_type", contravariant_type;
303 InvariantTypeItem, "invariant_type", invariant_type;
305 CovariantLifetimeItem, "covariant_lifetime", covariant_lifetime;
306 ContravariantLifetimeItem, "contravariant_lifetime", contravariant_lifetime;
307 InvariantLifetimeItem, "invariant_lifetime", invariant_lifetime;
309 NoSendItem, "no_send_bound", no_send_bound;
310 NoCopyItem, "no_copy_bound", no_copy_bound;
311 NoSyncItem, "no_sync_bound", no_sync_bound;
312 ManagedItem, "managed_bound", managed_bound;
314 IteratorItem, "iterator", iterator;
316 StackExhaustedLangItem, "stack_exhausted", stack_exhausted;