Fix regression when include!()ing a macro_rules! containing a $crate:: path.

Author: jseyfried

src/librustc_resolve/build_reduced_graph.rs

@@ -23,7 +23,7 @@ use {resolve_error, resolve_struct_error, ResolutionError};
 
 use rustc::middle::cstore::LoadedMacro;
 use rustc::hir::def::*;
-use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefId};
+use rustc::hir::def_id::{CrateNum, BUILTIN_MACROS_CRATE, CRATE_DEF_INDEX, DefId};
 use rustc::ty;
 
 use std::cell::Cell;
@@ -496,6 +496,9 @@ impl<'a> Resolver<'a> {
         let def_id = self.macro_defs[&expansion];
         if let Some(id) = self.definitions.as_local_node_id(def_id) {
             self.local_macro_def_scopes[&id]
+        } else if def_id.krate == BUILTIN_MACROS_CRATE {
+            // FIXME(jseyfried): This happens when `include!()`ing a `$crate::` path, c.f, #40469.
+            self.graph_root
         } else {
             let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
             self.get_extern_crate_root(module_def_id.krate)

src/test/run-pass/auxiliary/issue_40469.rs

@@ -0,0 +1,11 @@
+// Copyright 2017 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.
+
+macro_rules! m { () => { $crate::main(); } }

src/test/run-pass/issue-40469.rs

@@ -0,0 +1,18 @@
+// Copyright 2017 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.
+
+// ignore-pretty issue #37195
+
+#![allow(dead_code)]
+
+include!("auxiliary/issue_40469.rs");
+fn f() { m!(); }
+
+fn main() {}