diff --git a/src/librustc/traits/mod.rs b/src/librustc/traits/mod.rs index 4893e24091127..58ab713ef2730 100644 --- a/src/librustc/traits/mod.rs +++ b/src/librustc/traits/mod.rs @@ -628,6 +628,11 @@ pub fn get_vtable_methods<'a, 'tcx>( |_, _| tcx.mk_region(ty::ReErased), |def, _| trait_ref.substs().type_for_def(def)); + // the trait type may have higher-ranked lifetimes in it; + // so erase them if they appear, so that we get the type + // at some particular call site + let substs = tcx.erase_late_bound_regions_and_normalize(&ty::Binder(substs)); + // It's possible that the method relies on where clauses that // do not hold for this particular set of type parameters. // Note that this method could then never be called, so we diff --git a/src/librustc_trans/collector.rs b/src/librustc_trans/collector.rs index 89f5c00e9c11a..b5f948442b774 100644 --- a/src/librustc_trans/collector.rs +++ b/src/librustc_trans/collector.rs @@ -1090,13 +1090,16 @@ fn create_trans_items_for_vtable_methods<'a, 'tcx>(scx: &SharedCrateContext<'a, trait_ty: ty::Ty<'tcx>, impl_ty: ty::Ty<'tcx>, output: &mut Vec>) { - assert!(!trait_ty.needs_subst() && !impl_ty.needs_subst()); + assert!(!trait_ty.needs_subst() && !trait_ty.has_escaping_regions() && + !impl_ty.needs_subst() && !impl_ty.has_escaping_regions()); if let ty::TyDynamic(ref trait_ty, ..) = trait_ty.sty { if let Some(principal) = trait_ty.principal() { let poly_trait_ref = principal.with_self_ty(scx.tcx(), impl_ty); let param_substs = scx.tcx().intern_substs(&[]); + assert!(!poly_trait_ref.has_escaping_regions()); + // Walk all methods of the trait, including those of its supertraits let methods = traits::get_vtable_methods(scx.tcx(), poly_trait_ref); let methods = methods.filter_map(|method| method) diff --git a/src/test/run-pass/issue-39292.rs b/src/test/run-pass/issue-39292.rs new file mode 100644 index 0000000000000..dc2b21f3470e8 --- /dev/null +++ b/src/test/run-pass/issue-39292.rs @@ -0,0 +1,26 @@ +// 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Regression test for issue #39292. The object vtable was being +// incorrectly left with a null pointer. + +trait Foo { + fn print<'a>(&'a self) where T: 'a { println!("foo"); } +} + +impl<'a> Foo<&'a ()> for () { } + +trait Bar: for<'a> Foo<&'a ()> { } + +impl Bar for () {} + +fn main() { + (&() as &Bar).print(); // Segfault +}