From 03dc30d3d523753b44daab007d67e160a9a9d794 Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Thu, 23 May 2019 21:41:10 +0200 Subject: [PATCH] Make sanitize_place iterate instead of recurse --- .../borrow_check/nll/type_check/mod.rs | 155 +++++++++--------- 1 file changed, 79 insertions(+), 76 deletions(-) diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs index 4589e4ef036..52c8f15c44b 100644 --- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs +++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs @@ -29,7 +29,7 @@ use rustc::infer::type_variable::TypeVariableOrigin; use rustc::mir::interpret::{InterpError::BoundsCheck, ConstValue}; use rustc::mir::tcx::PlaceTy; -use rustc::mir::visit::{PlaceContext, Visitor, MutatingUseContext, NonMutatingUseContext}; +use rustc::mir::visit::{PlaceContext, Visitor, NonMutatingUseContext}; use rustc::mir::*; use rustc::traits::query::type_op; use rustc::traits::query::type_op::custom::CustomTypeOp; @@ -447,92 +447,95 @@ fn sanitize_place( context: PlaceContext, ) -> PlaceTy<'tcx> { debug!("sanitize_place: {:?}", place); - let place_ty = match place { - Place::Base(PlaceBase::Local(index)) => - PlaceTy::from_ty(self.mir.local_decls[*index].ty), - Place::Base(PlaceBase::Static(box Static { kind, ty: sty })) => { - let sty = self.sanitize_type(place, sty); - let check_err = - |verifier: &mut TypeVerifier<'a, 'b, 'gcx, 'tcx>, - place: &Place<'tcx>, - ty, - sty| { - if let Err(terr) = verifier.cx.eq_types( - sty, - ty, - location.to_locations(), - ConstraintCategory::Boring, - ) { - span_mirbug!( - verifier, - place, - "bad promoted type ({:?}: {:?}): {:?}", - ty, - sty, - terr - ); - }; - }; - match kind { - StaticKind::Promoted(promoted) => { - if !self.errors_reported { - let promoted_mir = &self.mir.promoted[*promoted]; - self.sanitize_promoted(promoted_mir, location); - let promoted_ty = promoted_mir.return_ty(); - check_err(self, place, promoted_ty, sty); + place.iterate(|place_base, place_projection| { + let mut place_ty = match place_base { + PlaceBase::Local(index) => + PlaceTy::from_ty(self.mir.local_decls[*index].ty), + PlaceBase::Static(box Static { kind, ty: sty }) => { + let sty = self.sanitize_type(place, sty); + let check_err = + |verifier: &mut TypeVerifier<'a, 'b, 'gcx, 'tcx>, + place: &Place<'tcx>, + ty, + sty| { + if let Err(terr) = verifier.cx.eq_types( + sty, + ty, + location.to_locations(), + ConstraintCategory::Boring, + ) { + span_mirbug!( + verifier, + place, + "bad promoted type ({:?}: {:?}): {:?}", + ty, + sty, + terr + ); + }; + }; + match kind { + StaticKind::Promoted(promoted) => { + if !self.errors_reported { + let promoted_mir = &self.mir.promoted[*promoted]; + self.sanitize_promoted(promoted_mir, location); + + let promoted_ty = promoted_mir.return_ty(); + check_err(self, place, promoted_ty, sty); + } + } + StaticKind::Static(def_id) => { + let ty = self.tcx().type_of(*def_id); + let ty = self.cx.normalize(ty, location); + + check_err(self, place, ty, sty); } } - StaticKind::Static(def_id) => { - let ty = self.tcx().type_of(*def_id); - let ty = self.cx.normalize(ty, location); - - check_err(self, place, ty, sty); - } + PlaceTy::from_ty(sty) + } + }; + + // FIXME use place_projection.is_empty() when is available + if let Place::Base(_) = place { + if let PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy) = context { + let tcx = self.tcx(); + let trait_ref = ty::TraitRef { + def_id: tcx.lang_items().copy_trait().unwrap(), + substs: tcx.mk_substs_trait(place_ty.ty, &[]), + }; + + // In order to have a Copy operand, the type T of the + // value must be Copy. Note that we prove that T: Copy, + // rather than using the `is_copy_modulo_regions` + // test. This is important because + // `is_copy_modulo_regions` ignores the resulting region + // obligations and assumes they pass. This can result in + // bounds from Copy impls being unsoundly ignored (e.g., + // #29149). Note that we decide to use Copy before knowing + // whether the bounds fully apply: in effect, the rule is + // that if a value of some type could implement Copy, then + // it must. + self.cx.prove_trait_ref( + trait_ref, + location.to_locations(), + ConstraintCategory::CopyBound, + ); } - PlaceTy::from_ty(sty) } - Place::Projection(ref proj) => { - let base_context = if context.is_mutating_use() { - PlaceContext::MutatingUse(MutatingUseContext::Projection) - } else { - PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection) - }; - let base_ty = self.sanitize_place(&proj.base, location, base_context); - if base_ty.variant_index.is_none() { - if base_ty.ty.references_error() { + + for proj in place_projection { + if place_ty.variant_index.is_none() { + if place_ty.ty.references_error() { assert!(self.errors_reported); return PlaceTy::from_ty(self.tcx().types.err); } } - self.sanitize_projection(base_ty, &proj.elem, place, location) + place_ty = self.sanitize_projection(place_ty, &proj.elem, place, location) } - }; - if let PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy) = context { - let tcx = self.tcx(); - let trait_ref = ty::TraitRef { - def_id: tcx.lang_items().copy_trait().unwrap(), - substs: tcx.mk_substs_trait(place_ty.ty, &[]), - }; - // In order to have a Copy operand, the type T of the - // value must be Copy. Note that we prove that T: Copy, - // rather than using the `is_copy_modulo_regions` - // test. This is important because - // `is_copy_modulo_regions` ignores the resulting region - // obligations and assumes they pass. This can result in - // bounds from Copy impls being unsoundly ignored (e.g., - // #29149). Note that we decide to use Copy before knowing - // whether the bounds fully apply: in effect, the rule is - // that if a value of some type could implement Copy, then - // it must. - self.cx.prove_trait_ref( - trait_ref, - location.to_locations(), - ConstraintCategory::CopyBound, - ); - } - place_ty + place_ty + }) } fn sanitize_promoted(&mut self, promoted_mir: &'b Mir<'tcx>, location: Location) {