diff options
| -rw-r--r-- | src/librustc_typeck/check_unused.rs | 19 | ||||
| -rw-r--r-- | src/test/rustdoc/issue-46271.rs | 15 |
2 files changed, 34 insertions, 0 deletions
diff --git a/src/librustc_typeck/check_unused.rs b/src/librustc_typeck/check_unused.rs index b867a655b4a..f2f1e2938cb 100644 --- a/src/librustc_typeck/check_unused.rs +++ b/src/librustc_typeck/check_unused.rs @@ -75,6 +75,25 @@ pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { tcx.hir.krate().visit_all_item_likes(&mut visitor); for &(def_id, span) in tcx.maybe_unused_extern_crates(LOCAL_CRATE).iter() { + // The `def_id` here actually was calculated during resolution (at least + // at the time of this writing) and is being shipped to us via a side + // channel of the tcx. There may have been extra expansion phases, + // however, which ended up removing the `def_id` *after* expansion such + // as the `ReplaceBodyWithLoop` pass (which is a bit of a hack, but hey) + // + // As a result we need to verify that `def_id` is indeed still valid for + // our AST and actually present in the HIR map. If it's not there then + // there's safely nothing to warn about, and otherwise we carry on with + // our execution. + // + // Note that if we carry through to the `extern_mod_stmt_cnum` query + // below it'll cause a panic because `def_id` is actually bogus at this + // point in time otherwise. + if let Some(id) = tcx.hir.as_local_node_id(def_id) { + if tcx.hir.find(id).is_none() { + continue + } + } let cnum = tcx.extern_mod_stmt_cnum(def_id).unwrap(); if tcx.is_compiler_builtins(cnum) { continue diff --git a/src/test/rustdoc/issue-46271.rs b/src/test/rustdoc/issue-46271.rs new file mode 100644 index 00000000000..cc3be08c568 --- /dev/null +++ b/src/test/rustdoc/issue-46271.rs @@ -0,0 +1,15 @@ +// 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. + +// hopefully this doesn't cause an ICE + +pub fn foo() { + extern crate std; +} |