From 98444ca53e8a589cd681fb2788fc37c4859d399c Mon Sep 17 00:00:00 2001 From: Camille GILLOT Date: Mon, 10 Feb 2020 20:26:24 +0100 Subject: [PATCH] Move opaque_types::unexpected_hidden_region_diagnostic to error_reporting. --- .../infer/error_reporting/mod.rs | 83 +++++++++++++++++- src/librustc_infer/infer/opaque_types/mod.rs | 84 +------------------ .../borrow_check/diagnostics/region_errors.rs | 5 +- 3 files changed, 85 insertions(+), 87 deletions(-) diff --git a/src/librustc_infer/infer/error_reporting/mod.rs b/src/librustc_infer/infer/error_reporting/mod.rs index 7e418898910..85c9e32a195 100644 --- a/src/librustc_infer/infer/error_reporting/mod.rs +++ b/src/librustc_infer/infer/error_reporting/mod.rs @@ -49,7 +49,6 @@ use super::lexical_region_resolve::RegionResolutionError; use super::region_constraints::GenericKind; use super::{InferCtxt, RegionVariableOrigin, SubregionOrigin, TypeTrace, ValuePairs}; -use crate::infer::opaque_types; use crate::infer::{self, SuppressRegionErrors}; use crate::traits::error_reporting::report_object_safety_error; use crate::traits::{ @@ -288,6 +287,86 @@ fn explain_span(tcx: TyCtxt<'tcx>, heading: &str, span: Span) -> (String, Option (format!("the {} at {}:{}", heading, lo.line, lo.col.to_usize() + 1), Some(span)) } +pub fn unexpected_hidden_region_diagnostic( + tcx: TyCtxt<'tcx>, + region_scope_tree: Option<®ion::ScopeTree>, + span: Span, + hidden_ty: Ty<'tcx>, + hidden_region: ty::Region<'tcx>, +) -> DiagnosticBuilder<'tcx> { + let mut err = struct_span_err!( + tcx.sess, + span, + E0700, + "hidden type for `impl Trait` captures lifetime that does not appear in bounds", + ); + + // Explain the region we are capturing. + if let ty::ReEarlyBound(_) | ty::ReFree(_) | ty::ReStatic | ty::ReEmpty(_) = hidden_region { + // Assuming regionck succeeded (*), we ought to always be + // capturing *some* region from the fn header, and hence it + // ought to be free. So under normal circumstances, we will go + // down this path which gives a decent human readable + // explanation. + // + // (*) if not, the `tainted_by_errors` flag would be set to + // true in any case, so we wouldn't be here at all. + note_and_explain_free_region( + tcx, + &mut err, + &format!("hidden type `{}` captures ", hidden_ty), + hidden_region, + "", + ); + } else { + // Ugh. This is a painful case: the hidden region is not one + // that we can easily summarize or explain. This can happen + // in a case like + // `src/test/ui/multiple-lifetimes/ordinary-bounds-unsuited.rs`: + // + // ``` + // fn upper_bounds<'a, 'b>(a: Ordinary<'a>, b: Ordinary<'b>) -> impl Trait<'a, 'b> { + // if condition() { a } else { b } + // } + // ``` + // + // Here the captured lifetime is the intersection of `'a` and + // `'b`, which we can't quite express. + + if let Some(region_scope_tree) = region_scope_tree { + // If the `region_scope_tree` is available, this is being + // invoked from the "region inferencer error". We can at + // least report a really cryptic error for now. + note_and_explain_region( + tcx, + region_scope_tree, + &mut err, + &format!("hidden type `{}` captures ", hidden_ty), + hidden_region, + "", + ); + } else { + // If the `region_scope_tree` is *unavailable*, this is + // being invoked by the code that comes *after* region + // inferencing. This is a bug, as the region inferencer + // ought to have noticed the failed constraint and invoked + // error reporting, which in turn should have prevented us + // from getting trying to infer the hidden type + // completely. + tcx.sess.delay_span_bug( + span, + &format!( + "hidden type captures unexpected lifetime `{:?}` \ + but no region inference failure", + hidden_region, + ), + ); + } + } + + err +} + impl<'a, 'tcx> InferCtxt<'a, 'tcx> { pub fn report_region_errors( &self, @@ -410,7 +489,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { span, } => { let hidden_ty = self.resolve_vars_if_possible(&hidden_ty); - opaque_types::unexpected_hidden_region_diagnostic( + unexpected_hidden_region_diagnostic( self.tcx, Some(region_scope_tree), span, diff --git a/src/librustc_infer/infer/opaque_types/mod.rs b/src/librustc_infer/infer/opaque_types/mod.rs index 4d264008ee3..c18c2755281 100644 --- a/src/librustc_infer/infer/opaque_types/mod.rs +++ b/src/librustc_infer/infer/opaque_types/mod.rs @@ -1,7 +1,6 @@ -use crate::infer::error_reporting::{note_and_explain_free_region, note_and_explain_region}; +use crate::infer::error_reporting::unexpected_hidden_region_diagnostic; use crate::infer::{self, InferCtxt, InferOk, TypeVariableOrigin, TypeVariableOriginKind}; use crate::traits::{self, PredicateObligation}; -use rustc::middle::region; use rustc::session::config::nightly_options; use rustc::ty::fold::{BottomUpFolder, TypeFoldable, TypeFolder, TypeVisitor}; use rustc::ty::free_region_map::FreeRegionRelations; @@ -9,7 +8,6 @@ use rustc::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef}; use rustc::ty::{self, GenericParamDefKind, Ty, TyCtxt}; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::Lrc; -use rustc_errors::{struct_span_err, DiagnosticBuilder}; use rustc_hir as hir; use rustc_hir::def_id::{DefId, DefIdMap}; use rustc_hir::Node; @@ -618,86 +616,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { } } -pub fn unexpected_hidden_region_diagnostic( - tcx: TyCtxt<'tcx>, - region_scope_tree: Option<®ion::ScopeTree>, - span: Span, - hidden_ty: Ty<'tcx>, - hidden_region: ty::Region<'tcx>, -) -> DiagnosticBuilder<'tcx> { - let mut err = struct_span_err!( - tcx.sess, - span, - E0700, - "hidden type for `impl Trait` captures lifetime that does not appear in bounds", - ); - - // Explain the region we are capturing. - if let ty::ReEarlyBound(_) | ty::ReFree(_) | ty::ReStatic | ty::ReEmpty(_) = hidden_region { - // Assuming regionck succeeded (*), we ought to always be - // capturing *some* region from the fn header, and hence it - // ought to be free. So under normal circumstances, we will go - // down this path which gives a decent human readable - // explanation. - // - // (*) if not, the `tainted_by_errors` flag would be set to - // true in any case, so we wouldn't be here at all. - note_and_explain_free_region( - tcx, - &mut err, - &format!("hidden type `{}` captures ", hidden_ty), - hidden_region, - "", - ); - } else { - // Ugh. This is a painful case: the hidden region is not one - // that we can easily summarize or explain. This can happen - // in a case like - // `src/test/ui/multiple-lifetimes/ordinary-bounds-unsuited.rs`: - // - // ``` - // fn upper_bounds<'a, 'b>(a: Ordinary<'a>, b: Ordinary<'b>) -> impl Trait<'a, 'b> { - // if condition() { a } else { b } - // } - // ``` - // - // Here the captured lifetime is the intersection of `'a` and - // `'b`, which we can't quite express. - - if let Some(region_scope_tree) = region_scope_tree { - // If the `region_scope_tree` is available, this is being - // invoked from the "region inferencer error". We can at - // least report a really cryptic error for now. - note_and_explain_region( - tcx, - region_scope_tree, - &mut err, - &format!("hidden type `{}` captures ", hidden_ty), - hidden_region, - "", - ); - } else { - // If the `region_scope_tree` is *unavailable*, this is - // being invoked by the code that comes *after* region - // inferencing. This is a bug, as the region inferencer - // ought to have noticed the failed constraint and invoked - // error reporting, which in turn should have prevented us - // from getting trying to infer the hidden type - // completely. - tcx.sess.delay_span_bug( - span, - &format!( - "hidden type captures unexpected lifetime `{:?}` \ - but no region inference failure", - hidden_region, - ), - ); - } - } - - err -} - // Visitor that requires that (almost) all regions in the type visited outlive // `least_region`. We cannot use `push_outlives_components` because regions in // closure signatures are not included in their outlives components. We need to diff --git a/src/librustc_mir/borrow_check/diagnostics/region_errors.rs b/src/librustc_mir/borrow_check/diagnostics/region_errors.rs index 8cd75d4a2fd..f751a16cfce 100644 --- a/src/librustc_mir/borrow_check/diagnostics/region_errors.rs +++ b/src/librustc_mir/borrow_check/diagnostics/region_errors.rs @@ -4,7 +4,8 @@ use rustc::mir::ConstraintCategory; use rustc::ty::{self, RegionVid, Ty}; use rustc_errors::{Applicability, DiagnosticBuilder}; use rustc_infer::infer::{ - error_reporting::nice_region_error::NiceRegionError, opaque_types, NLLRegionVariableOrigin, + error_reporting::nice_region_error::NiceRegionError, + error_reporting::unexpected_hidden_region_diagnostic, NLLRegionVariableOrigin, }; use rustc_span::symbol::kw; use rustc_span::Span; @@ -197,7 +198,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> { let region_scope_tree = &self.infcx.tcx.region_scope_tree(self.mir_def_id); let named_ty = self.regioncx.name_regions(self.infcx.tcx, hidden_ty); let named_region = self.regioncx.name_regions(self.infcx.tcx, member_region); - opaque_types::unexpected_hidden_region_diagnostic( + unexpected_hidden_region_diagnostic( self.infcx.tcx, Some(region_scope_tree), span,