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// Copyright 2014 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.
//! Validity checking for weak lang items
use driver::config;
use driver::session::Session;
use metadata::csearch;
use middle::lang_items;
use syntax::ast;
use syntax::codemap::Span;
use syntax::parse::token::InternedString;
use syntax::visit::Visitor;
use syntax::visit;
use std::collections::HashSet;
macro_rules! weak_lang_items( ($($name:ident, $item:ident, $sym:ident;)*) => (
struct Context<'a> {
sess: &'a Session,
items: &'a mut lang_items::LanguageItems,
}
/// Checks the crate for usage of weak lang items, returning a vector of all the
/// language items required by this crate, but not defined yet.
pub fn check_crate(krate: &ast::Crate,
sess: &Session,
items: &mut lang_items::LanguageItems) {
// These are never called by user code, they're generated by the compiler.
// They will never implicitly be added to the `missing` array unless we do
// so here.
if items.stack_exhausted().is_none() {
items.missing.push(lang_items::StackExhaustedLangItem);
}
if items.eh_personality().is_none() {
items.missing.push(lang_items::EhPersonalityLangItem);
}
{
let mut cx = Context { sess: sess, items: items };
visit::walk_crate(&mut cx, krate);
}
verify(sess, items);
}
pub fn link_name(attrs: &[ast::Attribute]) -> Option<InternedString> {
lang_items::extract(attrs).and_then(|name| {
$(if name.get() == stringify!($name) {
Some(InternedString::new(stringify!($sym)))
} else)* {
None
}
})
}
fn verify(sess: &Session, items: &lang_items::LanguageItems) {
// We only need to check for the presence of weak lang items if we're
// emitting something that's not an rlib.
let needs_check = sess.crate_types.borrow().iter().any(|kind| {
match *kind {
config::CrateTypeDylib |
config::CrateTypeExecutable |
config::CrateTypeStaticlib => true,
config::CrateTypeRlib => false,
}
});
if !needs_check { return }
let mut missing = HashSet::new();
sess.cstore.iter_crate_data(|cnum, _| {
for item in csearch::get_missing_lang_items(&sess.cstore, cnum).iter() {
missing.insert(*item);
}
});
$(
if missing.contains(&lang_items::$item) && items.$name().is_none() {
sess.err(format!("language item required, but not found: `{}`",
stringify!($name)).as_slice());
}
)*
}
impl<'a> Context<'a> {
fn register(&mut self, name: &str, span: Span) {
$(if name == stringify!($name) {
if self.items.$name().is_none() {
self.items.missing.push(lang_items::$item);
}
} else)* {
self.sess.span_err(span,
format!("unknown external lang item: `{}`",
name).as_slice());
}
}
}
impl<'a, 'v> Visitor<'v> for Context<'a> {
fn visit_foreign_item(&mut self, i: &ast::ForeignItem) {
match lang_items::extract(i.attrs.as_slice()) {
None => {}
Some(lang_item) => self.register(lang_item.get(), i.span),
}
visit::walk_foreign_item(self, i)
}
}
) )
weak_lang_items!(
fail_fmt, FailFmtLangItem, rust_begin_unwind;
stack_exhausted, StackExhaustedLangItem, rust_stack_exhausted;
eh_personality, EhPersonalityLangItem, rust_eh_personality;
)
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