src/librustc_driver/derive_registrar.rs

   1 // Copyright 2016 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.
   4 //
   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.
  10
  11 use rustc::dep_graph::DepNode;
  12 use rustc::hir::intravisit::Visitor;
  13 use rustc::hir::map::Map;
  14 use rustc::hir;
  15 use syntax::ast;
  16 use syntax::attr;
  17
  18 pub fn find(hir_map: &Map) -> Option<ast::NodeId> {
  19     let _task = hir_map.dep_graph.in_task(DepNode::PluginRegistrar);
  20     let krate = hir_map.krate();
  21
  22     let mut finder = Finder { registrar: None };
  23     krate.visit_all_items(&mut finder);
  24     finder.registrar
  25 }
  26
  27 struct Finder {
  28     registrar: Option<ast::NodeId>,
  29 }
  30
  31 impl<'v> Visitor<'v> for Finder {
  32     fn visit_item(&mut self, item: &hir::Item) {
  33         if attr::contains_name(&item.attrs, "rustc_derive_registrar") {
  34             self.registrar = Some(item.id);
  35         }
  36     }
  37 }