| // Copyright 2012-2013 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. |
| |
| //! Used by `rustc` when compiling a plugin crate. |
| |
| use syntax::ast; |
| use syntax::attr; |
| use errors; |
| use syntax_pos::Span; |
| use rustc::dep_graph::DepNode; |
| use rustc::hir::map::Map; |
| use rustc::hir::intravisit::Visitor; |
| use rustc::hir; |
| |
| struct RegistrarFinder { |
| registrars: Vec<(ast::NodeId, Span)> , |
| } |
| |
| impl<'v> Visitor<'v> for RegistrarFinder { |
| fn visit_item(&mut self, item: &hir::Item) { |
| if let hir::ItemFn(..) = item.node { |
| if attr::contains_name(&item.attrs, |
| "plugin_registrar") { |
| self.registrars.push((item.id, item.span)); |
| } |
| } |
| } |
| } |
| |
| /// Find the function marked with `#[plugin_registrar]`, if any. |
| pub fn find_plugin_registrar(diagnostic: &errors::Handler, |
| hir_map: &Map) |
| -> Option<ast::NodeId> { |
| let _task = hir_map.dep_graph.in_task(DepNode::PluginRegistrar); |
| let krate = hir_map.krate(); |
| |
| let mut finder = RegistrarFinder { registrars: Vec::new() }; |
| krate.visit_all_items(&mut finder); |
| |
| match finder.registrars.len() { |
| 0 => None, |
| 1 => { |
| let (node_id, _) = finder.registrars.pop().unwrap(); |
| Some(node_id) |
| }, |
| _ => { |
| let mut e = diagnostic.struct_err("multiple plugin registration functions found"); |
| for &(_, span) in &finder.registrars { |
| e.span_note(span, "one is here"); |
| } |
| e.emit(); |
| diagnostic.abort_if_errors(); |
| unreachable!(); |
| } |
| } |
| } |