1 // Copyright 2014 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 //! Validity checking for weak lang items
15 use metadata::csearch;
16 use middle::lang_items;
19 use syntax::codemap::Span;
20 use syntax::parse::token::InternedString;
21 use rustc_front::intravisit::Visitor;
22 use rustc_front::intravisit;
25 use std::collections::HashSet;
27 macro_rules! weak_lang_items {
28 ($($name:ident, $item:ident, $sym:ident;)*) => (
32 items: &'a mut lang_items::LanguageItems,
35 /// Checks the crate for usage of weak lang items, returning a vector of all the
36 /// language items required by this crate, but not defined yet.
37 pub fn check_crate(krate: &hir::Crate,
39 items: &mut lang_items::LanguageItems) {
40 // These are never called by user code, they're generated by the compiler.
41 // They will never implicitly be added to the `missing` array unless we do
43 if items.eh_personality().is_none() {
44 items.missing.push(lang_items::EhPersonalityLangItem);
46 if sess.target.target.options.custom_unwind_resume &
47 items.eh_unwind_resume().is_none() {
48 items.missing.push(lang_items::EhUnwindResumeLangItem);
52 let mut cx = Context { sess: sess, items: items };
53 krate.visit_all_items(&mut cx);
58 pub fn link_name(attrs: &[ast::Attribute]) -> Option<InternedString> {
59 lang_items::extract(attrs).and_then(|name| {
60 $(if &name[..] == stringify!($name) {
61 Some(InternedString::new(stringify!($sym)))
68 fn verify(sess: &Session, items: &lang_items::LanguageItems) {
69 // We only need to check for the presence of weak lang items if we're
70 // emitting something that's not an rlib.
71 let needs_check = sess.crate_types.borrow().iter().any(|kind| {
73 config::CrateTypeDylib |
74 config::CrateTypeExecutable |
75 config::CrateTypeStaticlib => true,
76 config::CrateTypeRlib => false,
79 if !needs_check { return }
81 let mut missing = HashSet::new();
82 sess.cstore.iter_crate_data(|cnum, _| {
83 for item in &csearch::get_missing_lang_items(&sess.cstore, cnum) {
84 missing.insert(*item);
89 if missing.contains(&lang_items::$item) && items.$name().is_none() {
90 sess.err(&format!("language item required, but not found: `{}`",
97 impl<'a> Context<'a> {
98 fn register(&mut self, name: &str, span: Span) {
99 $(if name == stringify!($name) {
100 if self.items.$name().is_none() {
101 self.items.missing.push(lang_items::$item);
104 span_err!(self.sess, span, E0264,
105 "unknown external lang item: `{}`",
111 impl<'a, 'v> Visitor<'v> for Context<'a> {
112 fn visit_foreign_item(&mut self, i: &hir::ForeignItem) {
113 match lang_items::extract(&i.attrs) {
115 Some(lang_item) => self.register(&lang_item, i.span),
117 intravisit::walk_foreign_item(self, i)
124 panic_fmt, PanicFmtLangItem, rust_begin_unwind;
125 eh_personality, EhPersonalityLangItem, rust_eh_personality;
126 eh_unwind_resume, EhUnwindResumeLangItem, rust_eh_unwind_resume;