rust/src/librustc/middle/lang_items.rs
2014-04-22 17:18:21 +03:00

279 lines
10 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// 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.
// Detecting language items.
//
// Language items are items that represent concepts intrinsic to the language
// itself. Examples are:
//
// * Traits that specify "kinds"; e.g. "Share", "Send".
//
// * Traits that represent operators; e.g. "Add", "Sub", "Index".
//
// * Functions called by the compiler itself.
use driver::session::Session;
use metadata::csearch::each_lang_item;
use middle::ty;
use syntax::ast;
use syntax::ast_util::local_def;
use syntax::attr::AttrMetaMethods;
use syntax::parse::token::InternedString;
use syntax::visit::Visitor;
use syntax::visit;
use collections::HashMap;
use std::iter::Enumerate;
use std::slice;
// The actual lang items defined come at the end of this file in one handy table.
// So you probably just want to nip down to the end.
macro_rules! lets_do_this {
(
$( $variant:ident, $name:expr, $method:ident; )*
) => {
#[deriving(FromPrimitive)]
pub enum LangItem {
$($variant),*
}
pub struct LanguageItems {
pub items: Vec<Option<ast::DefId>> ,
}
impl LanguageItems {
pub fn new() -> LanguageItems {
fn foo(_: LangItem) -> Option<ast::DefId> { None }
LanguageItems {
items: vec!($(foo($variant)),*)
}
}
pub fn items<'a>(&'a self) -> Enumerate<slice::Items<'a, Option<ast::DefId>>> {
self.items.iter().enumerate()
}
pub fn item_name(index: uint) -> &'static str {
let item: Option<LangItem> = FromPrimitive::from_uint(index);
match item {
$( Some($variant) => $name, )*
None => "???"
}
}
pub fn require(&self, it: LangItem) -> Result<ast::DefId, ~str> {
match self.items.get(it as uint) {
&Some(id) => Ok(id),
&None => {
Err(format!("requires `{}` lang_item",
LanguageItems::item_name(it as uint)))
}
}
}
pub fn to_builtin_kind(&self, id: ast::DefId) -> Option<ty::BuiltinBound> {
if Some(id) == self.send_trait() {
Some(ty::BoundSend)
} else if Some(id) == self.sized_trait() {
Some(ty::BoundSized)
} else if Some(id) == self.copy_trait() {
Some(ty::BoundCopy)
} else if Some(id) == self.share_trait() {
Some(ty::BoundShare)
} else {
None
}
}
$(
#[allow(dead_code)]
pub fn $method(&self) -> Option<ast::DefId> {
*self.items.get($variant as uint)
}
)*
}
struct LanguageItemCollector<'a> {
items: LanguageItems,
session: &'a Session,
item_refs: HashMap<&'static str, uint>,
}
impl<'a> Visitor<()> for LanguageItemCollector<'a> {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
match extract(item.attrs.as_slice()) {
Some(value) => {
let item_index = self.item_refs.find_equiv(&value).map(|x| *x);
match item_index {
Some(item_index) => {
self.collect_item(item_index, local_def(item.id))
}
None => {}
}
}
None => {}
}
visit::walk_item(self, item, ());
}
}
impl<'a> LanguageItemCollector<'a> {
pub fn new(session: &'a Session) -> LanguageItemCollector<'a> {
let mut item_refs = HashMap::new();
$( item_refs.insert($name, $variant as uint); )*
LanguageItemCollector {
session: session,
items: LanguageItems::new(),
item_refs: item_refs
}
}
pub fn collect_item(&mut self, item_index: uint, item_def_id: ast::DefId) {
// Check for duplicates.
match self.items.items.get(item_index) {
&Some(original_def_id) if original_def_id != item_def_id => {
self.session.err(format!("duplicate entry for `{}`",
LanguageItems::item_name(item_index)));
}
&Some(_) | &None => {
// OK.
}
}
// Matched.
*self.items.items.get_mut(item_index) = Some(item_def_id);
}
pub fn collect_local_language_items(&mut self, krate: &ast::Crate) {
visit::walk_crate(self, krate, ());
}
pub fn collect_external_language_items(&mut self) {
let crate_store = &self.session.cstore;
crate_store.iter_crate_data(|crate_number, _crate_metadata| {
each_lang_item(crate_store, crate_number, |node_id, item_index| {
let def_id = ast::DefId { krate: crate_number, node: node_id };
self.collect_item(item_index, def_id);
true
});
})
}
pub fn collect(&mut self, krate: &ast::Crate) {
self.collect_local_language_items(krate);
self.collect_external_language_items();
}
}
pub fn extract(attrs: &[ast::Attribute]) -> Option<InternedString> {
for attribute in attrs.iter() {
match attribute.name_str_pair() {
Some((ref key, ref value)) if key.equiv(&("lang")) => {
return Some((*value).clone());
}
Some(..) | None => {}
}
}
return None;
}
pub fn collect_language_items(krate: &ast::Crate,
session: &Session) -> LanguageItems {
let mut collector = LanguageItemCollector::new(session);
collector.collect(krate);
let LanguageItemCollector { items, .. } = collector;
session.abort_if_errors();
items
}
// End of the macro
}
}
lets_do_this! {
// Variant name, Name, Method name;
SendTraitLangItem, "send", send_trait;
SizedTraitLangItem, "sized", sized_trait;
CopyTraitLangItem, "copy", copy_trait;
ShareTraitLangItem, "share", share_trait;
DropTraitLangItem, "drop", drop_trait;
AddTraitLangItem, "add", add_trait;
SubTraitLangItem, "sub", sub_trait;
MulTraitLangItem, "mul", mul_trait;
DivTraitLangItem, "div", div_trait;
RemTraitLangItem, "rem", rem_trait;
NegTraitLangItem, "neg", neg_trait;
NotTraitLangItem, "not", not_trait;
BitXorTraitLangItem, "bitxor", bitxor_trait;
BitAndTraitLangItem, "bitand", bitand_trait;
BitOrTraitLangItem, "bitor", bitor_trait;
ShlTraitLangItem, "shl", shl_trait;
ShrTraitLangItem, "shr", shr_trait;
IndexTraitLangItem, "index", index_trait;
UnsafeTypeLangItem, "unsafe", unsafe_type;
DerefTraitLangItem, "deref", deref_trait;
DerefMutTraitLangItem, "deref_mut", deref_mut_trait;
EqTraitLangItem, "eq", eq_trait;
OrdTraitLangItem, "ord", ord_trait;
StrEqFnLangItem, "str_eq", str_eq_fn;
UniqStrEqFnLangItem, "uniq_str_eq", uniq_str_eq_fn;
FailFnLangItem, "fail_", fail_fn;
FailBoundsCheckFnLangItem, "fail_bounds_check", fail_bounds_check_fn;
ExchangeMallocFnLangItem, "exchange_malloc", exchange_malloc_fn;
ClosureExchangeMallocFnLangItem, "closure_exchange_malloc", closure_exchange_malloc_fn;
ExchangeFreeFnLangItem, "exchange_free", exchange_free_fn;
MallocFnLangItem, "malloc", malloc_fn;
FreeFnLangItem, "free", free_fn;
StrDupUniqFnLangItem, "strdup_uniq", strdup_uniq_fn;
StartFnLangItem, "start", start_fn;
TyDescStructLangItem, "ty_desc", ty_desc;
TyVisitorTraitLangItem, "ty_visitor", ty_visitor;
OpaqueStructLangItem, "opaque", opaque;
TypeIdLangItem, "type_id", type_id;
EhPersonalityLangItem, "eh_personality", eh_personality_fn;
ManagedHeapLangItem, "managed_heap", managed_heap;
ExchangeHeapLangItem, "exchange_heap", exchange_heap;
GcLangItem, "gc", gc;
CovariantTypeItem, "covariant_type", covariant_type;
ContravariantTypeItem, "contravariant_type", contravariant_type;
InvariantTypeItem, "invariant_type", invariant_type;
CovariantLifetimeItem, "covariant_lifetime", covariant_lifetime;
ContravariantLifetimeItem, "contravariant_lifetime", contravariant_lifetime;
InvariantLifetimeItem, "invariant_lifetime", invariant_lifetime;
NoSendItem, "no_send_bound", no_send_bound;
NoCopyItem, "no_copy_bound", no_copy_bound;
NoShareItem, "no_share_bound", no_share_bound;
ManagedItem, "managed_bound", managed_bound;
}