Skip to content

Commit

Permalink
Fix issue rust-lang#36036.
Browse files Browse the repository at this point in the history
We were treating an associated type as unsized even when the concrete
instantiation was actually sized. Fix is to normalize before checking
if it is sized.
  • Loading branch information
pnkfelix authored and jakllsch committed Sep 8, 2016
1 parent 4288257 commit 2e84fda
Show file tree
Hide file tree
Showing 2 changed files with 37 additions and 1 deletion.
2 changes: 1 addition & 1 deletion src/librustc/ty/layout.rs
Original file line number Diff line number Diff line change
Expand Up @@ -856,10 +856,10 @@ impl<'a, 'gcx, 'tcx> Layout {
ty::TyRef(_, ty::TypeAndMut { ty: pointee, .. }) |
ty::TyRawPtr(ty::TypeAndMut { ty: pointee, .. }) => {
let non_zero = !ty.is_unsafe_ptr();
let pointee = normalize_associated_type(infcx, pointee);
if pointee.is_sized(tcx, &infcx.parameter_environment, DUMMY_SP) {
Scalar { value: Pointer, non_zero: non_zero }
} else {
let pointee = normalize_associated_type(infcx, pointee);
let unsized_part = tcx.struct_tail(pointee);
let meta = match unsized_part.sty {
ty::TySlice(_) | ty::TyStr => {
Expand Down
36 changes: 36 additions & 0 deletions src/test/run-pass/issue-36036-associated-type-layout.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,36 @@
// Copyright 2016 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.

// Issue 36036: computing the layout of a type composed from another
// trait's associated type caused compiler to ICE when the associated
// type was allowed to be unsized, even though the known instantiated
// type is itself sized.

#![allow(dead_code)]

trait Context {
type Container: ?Sized;
}

impl Context for u16 {
type Container = u8;
}

struct Wrapper<C: Context+'static> {
container: &'static C::Container
}

fn foobar(_: Wrapper<u16>) {}

static VALUE: u8 = 0;

fn main() {
foobar(Wrapper { container: &VALUE });
}

0 comments on commit 2e84fda

Please sign in to comment.