From 9d35e57907ce2a57446e94dcf9e3403a51de6205 Mon Sep 17 00:00:00 2001 From: Masaki Hara Date: Tue, 27 Nov 2018 23:37:59 +0900 Subject: [PATCH 1/2] Normalize type before deferred sizedness checking. --- src/librustc_typeck/check/mod.rs | 1 + src/test/run-pass/issue-56237.rs | 11 +++++++++++ 2 files changed, 12 insertions(+) create mode 100644 src/test/run-pass/issue-56237.rs diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index e30a79b25de7f..44aa52651b0aa 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -914,6 +914,7 @@ fn typeck_tables_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, fcx.resolve_generator_interiors(def_id); for (ty, span, code) in fcx.deferred_sized_obligations.borrow_mut().drain(..) { + let ty = fcx.normalize_ty(span, ty); fcx.require_type_is_sized(ty, span, code); } fcx.select_all_obligations_or_error(); diff --git a/src/test/run-pass/issue-56237.rs b/src/test/run-pass/issue-56237.rs new file mode 100644 index 0000000000000..87e10e83612d6 --- /dev/null +++ b/src/test/run-pass/issue-56237.rs @@ -0,0 +1,11 @@ +use std::ops::Deref; + +fn foo

(_value:

::Target) +where + P: Deref, +

::Target: Sized, +{} + +fn main() { + foo::>(2); +} From 8cab350c85b9738e4dbc99c67e71bd4a5b6f62a7 Mon Sep 17 00:00:00 2001 From: Masaki Hara Date: Wed, 28 Nov 2018 23:59:19 +0900 Subject: [PATCH 2/2] Don't use ReErased in deferred sizedness checking. --- src/librustc_typeck/check/mod.rs | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 44aa52651b0aa..a107cec9ef41b 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -3970,7 +3970,13 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // // to work in stable even if the Sized bound on `drop` is relaxed. for i in 0..fn_sig.inputs().skip_binder().len() { - let input = tcx.erase_late_bound_regions(&fn_sig.input(i)); + // We just want to check sizedness, so instead of introducing + // placeholder lifetimes with probing, we just replace higher lifetimes + // with fresh vars. + let input = self.replace_bound_vars_with_fresh_vars( + expr.span, + infer::LateBoundRegionConversionTime::FnCall, + &fn_sig.input(i)).0; self.require_type_is_sized_deferred(input, expr.span, traits::SizedArgumentType); } @@ -3978,7 +3984,13 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // Here we want to prevent struct constructors from returning unsized types. // There were two cases this happened: fn pointer coercion in stable // and usual function call in presense of unsized_locals. - let output = tcx.erase_late_bound_regions(&fn_sig.output()); + // Also, as we just want to check sizedness, instead of introducing + // placeholder lifetimes with probing, we just replace higher lifetimes + // with fresh vars. + let output = self.replace_bound_vars_with_fresh_vars( + expr.span, + infer::LateBoundRegionConversionTime::FnCall, + &fn_sig.output()).0; self.require_type_is_sized_deferred(output, expr.span, traits::SizedReturnType); }