From e00263438c95e1e31eb76548b1e08b81e5f50a4a Mon Sep 17 00:00:00 2001 From: Ariel Ben-Yehuda Date: Mon, 21 Aug 2017 14:11:57 +0300 Subject: [PATCH 1/2] register fn-ptr coercion obligations out of a snapshot Fixes #43923. --- src/librustc_typeck/check/coercion.rs | 3 +-- src/test/run-pass/issue-43923.rs | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+), 2 deletions(-) create mode 100644 src/test/run-pass/issue-43923.rs diff --git a/src/librustc_typeck/check/coercion.rs b/src/librustc_typeck/check/coercion.rs index 48671e864b211..0ec30fb26d66a 100644 --- a/src/librustc_typeck/check/coercion.rs +++ b/src/librustc_typeck/check/coercion.rs @@ -807,8 +807,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let lub_ty = self.commit_if_ok(|_| { self.at(cause, self.param_env) .lub(prev_ty, new_ty) - .map(|ok| self.register_infer_ok_obligations(ok)) - }); + }).map(|ok| self.register_infer_ok_obligations(ok)); if lub_ty.is_ok() { // We have a LUB of prev_ty and new_ty, just return it. diff --git a/src/test/run-pass/issue-43923.rs b/src/test/run-pass/issue-43923.rs new file mode 100644 index 0000000000000..e1992e4fc5032 --- /dev/null +++ b/src/test/run-pass/issue-43923.rs @@ -0,0 +1,19 @@ +// 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +struct A { ptr: T } + +fn foo(x: &A<[T]>) {} + +fn main() { + let a = foo; + let b = A { ptr: [a, a, a] }; + a(&A { ptr: [()] }); +} From b47bcc2ee86debf37ff61b14d9b57361c7dd0ab8 Mon Sep 17 00:00:00 2001 From: Ariel Ben-Yehuda Date: Mon, 21 Aug 2017 14:26:33 +0300 Subject: [PATCH 2/2] fix other cases of registering obligations in a snapshot No test cases for these ones, but they would all ICE if they ever run with a non-empty set of obligations. --- src/librustc_typeck/check/coercion.rs | 6 ++---- src/librustc_typeck/check/regionck.rs | 10 +++++----- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/src/librustc_typeck/check/coercion.rs b/src/librustc_typeck/check/coercion.rs index 0ec30fb26d66a..e406ce845a6d1 100644 --- a/src/librustc_typeck/check/coercion.rs +++ b/src/librustc_typeck/check/coercion.rs @@ -883,8 +883,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { return self.commit_if_ok(|_| { self.at(cause, self.param_env) .lub(prev_ty, new_ty) - .map(|ok| self.register_infer_ok_obligations(ok)) - }); + }).map(|ok| self.register_infer_ok_obligations(ok)); } } @@ -897,8 +896,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { self.commit_if_ok(|_| { self.at(cause, self.param_env) .lub(prev_ty, new_ty) - .map(|ok| self.register_infer_ok_obligations(ok)) - }) + }).map(|ok| self.register_infer_ok_obligations(ok)) } } Ok(ok) => { diff --git a/src/librustc_typeck/check/regionck.rs b/src/librustc_typeck/check/regionck.rs index 73c243d27d1cf..1a61b8e29f231 100644 --- a/src/librustc_typeck/check/regionck.rs +++ b/src/librustc_typeck/check/regionck.rs @@ -1815,12 +1815,12 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> { // check whether this predicate applies to our current projection let cause = self.fcx.misc(span); match self.at(&cause, self.fcx.param_env).eq(outlives.0, ty) { - Ok(ok) => { - self.register_infer_ok_obligations(ok); - Ok(outlives.1) - } - Err(_) => { Err(()) } + Ok(ok) => Ok((ok, outlives.1)), + Err(_) => Err(()) } + }).map(|(ok, result)| { + self.register_infer_ok_obligations(ok); + result }); debug!("projection_bounds: region_result={:?}",