Introduce rustc_interface and move some methods there

1 files changed, 48 insertions, 0 deletions

diff --git a/src/librustc_interface/proc_macro_decls.rs b/src/librustc_interface/proc_macro_decls.rs
new file mode 100644
index 00000000000..093d15b7e3c
--- /dev/null
+++ b/src/librustc_interface/proc_macro_decls.rs
@@ -0,0 +1,48 @@
+use rustc::hir::itemlikevisit::ItemLikeVisitor;
+use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
+use rustc::hir;
+use rustc::ty::TyCtxt;
+use rustc::ty::query::Providers;
+use syntax::ast;
+use syntax::attr;
+
+pub fn find<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) -> Option<DefId> {
+    tcx.proc_macro_decls_static(LOCAL_CRATE)
+}
+
+fn proc_macro_decls_static<'tcx>(
+    tcx: TyCtxt<'_, 'tcx, 'tcx>,
+    cnum: CrateNum,
+) -> Option<DefId> {
+    assert_eq!(cnum, LOCAL_CRATE);
+
+    let mut finder = Finder { decls: None };
+    tcx.hir().krate().visit_all_item_likes(&mut finder);
+
+    finder.decls.map(|id| tcx.hir().local_def_id(id))
+}
+
+struct Finder {
+    decls: Option<ast::NodeId>,
+}
+
+impl<'v> ItemLikeVisitor<'v> for Finder {
+    fn visit_item(&mut self, item: &hir::Item) {
+        if attr::contains_name(&item.attrs, "rustc_proc_macro_decls") {
+            self.decls = Some(item.id);
+        }
+    }
+
+    fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem) {
+    }
+
+    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
+    }
+}
+
+pub(crate) fn provide(providers: &mut Providers<'_>) {
+    *providers = Providers {
+        proc_macro_decls_static,
+        ..*providers
+    };
+}