diff options
Diffstat (limited to 'compiler/rustc_middle/src/ty/print/pretty.rs')
| -rw-r--r-- | compiler/rustc_middle/src/ty/print/pretty.rs | 192 |
1 files changed, 142 insertions, 50 deletions
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index 5303341ba..ae7c20fff 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -10,12 +10,13 @@ use rustc_data_structures::sso::SsoHashSet; use rustc_hir as hir; use rustc_hir::def::{self, CtorKind, DefKind, Namespace}; use rustc_hir::def_id::{DefId, DefIdSet, CRATE_DEF_ID, LOCAL_CRATE}; -use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData}; +use rustc_hir::definitions::{DefKey, DefPathData, DefPathDataName, DisambiguatedDefPathData}; use rustc_hir::LangItem; use rustc_session::config::TrimmedDefPaths; use rustc_session::cstore::{ExternCrate, ExternCrateSource}; use rustc_session::Limit; use rustc_span::symbol::{kw, Ident, Symbol}; +use rustc_span::FileNameDisplayPreference; use rustc_target::abi::Size; use rustc_target::spec::abi::Abi; use smallvec::SmallVec; @@ -23,7 +24,6 @@ use smallvec::SmallVec; use std::cell::Cell; use std::char; use std::collections::BTreeMap; -use std::convert::TryFrom; use std::fmt::{self, Write as _}; use std::iter; use std::ops::{ControlFlow, Deref, DerefMut}; @@ -63,6 +63,7 @@ thread_local! { static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) }; static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) }; static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) }; + static FORCE_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) }; static NO_QUERIES: Cell<bool> = const { Cell::new(false) }; static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) }; } @@ -116,6 +117,7 @@ define_helper!( /// of various rustc types, for example `std::vec::Vec` would be trimmed to `Vec`, /// if no other `Vec` is found. fn with_no_trimmed_paths(NoTrimmedGuard, NO_TRIMMED_PATH); + fn with_forced_trimmed_paths(ForceTrimmedGuard, FORCE_TRIMMED_PATH); /// Prevent selection of visible paths. `Display` impl of DefId will prefer /// visible (public) reexports of types as paths. fn with_no_visible_paths(NoVisibleGuard, NO_VISIBLE_PATH); @@ -281,6 +283,8 @@ pub trait PrettyPrinter<'tcx>: /// This is typically the case for all non-`'_` regions. fn should_print_region(&self, region: ty::Region<'tcx>) -> bool; + fn reset_type_limit(&mut self) {} + // Defaults (should not be overridden): /// If possible, this returns a global path resolving to `def_id` that is visible @@ -295,11 +299,89 @@ pub trait PrettyPrinter<'tcx>: self.try_print_visible_def_path_recur(def_id, &mut callers) } + // Given a `DefId`, produce a short name. For types and traits, it prints *only* its name, + // For associated items on traits it prints out the trait's name and the associated item's name. + // For enum variants, if they have an unique name, then we only print the name, otherwise we + // print the enum name and the variant name. Otherwise, we do not print anything and let the + // caller use the `print_def_path` fallback. + fn force_print_trimmed_def_path( + mut self, + def_id: DefId, + ) -> Result<(Self::Path, bool), Self::Error> { + let key = self.tcx().def_key(def_id); + let visible_parent_map = self.tcx().visible_parent_map(()); + let kind = self.tcx().def_kind(def_id); + + let get_local_name = |this: &Self, name, def_id, key: DefKey| { + if let Some(visible_parent) = visible_parent_map.get(&def_id) + && let actual_parent = this.tcx().opt_parent(def_id) + && let DefPathData::TypeNs(_) = key.disambiguated_data.data + && Some(*visible_parent) != actual_parent + { + this + .tcx() + .module_children(visible_parent) + .iter() + .filter(|child| child.res.opt_def_id() == Some(def_id)) + .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore) + .map(|child| child.ident.name) + .unwrap_or(name) + } else { + name + } + }; + if let DefKind::Variant = kind + && let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id) + { + // If `Assoc` is unique, we don't want to talk about `Trait::Assoc`. + self.write_str(get_local_name(&self, *symbol, def_id, key).as_str())?; + return Ok((self, true)); + } + if let Some(symbol) = key.get_opt_name() { + if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = kind + && let Some(parent) = self.tcx().opt_parent(def_id) + && let parent_key = self.tcx().def_key(parent) + && let Some(symbol) = parent_key.get_opt_name() + { + // Trait + self.write_str(get_local_name(&self, symbol, parent, parent_key).as_str())?; + self.write_str("::")?; + } else if let DefKind::Variant = kind + && let Some(parent) = self.tcx().opt_parent(def_id) + && let parent_key = self.tcx().def_key(parent) + && let Some(symbol) = parent_key.get_opt_name() + { + // Enum + + // For associated items and variants, we want the "full" path, namely, include + // the parent type in the path. For example, `Iterator::Item`. + self.write_str(get_local_name(&self, symbol, parent, parent_key).as_str())?; + self.write_str("::")?; + } else if let DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Trait + | DefKind::TyAlias | DefKind::Fn | DefKind::Const | DefKind::Static(_) = kind + { + } else { + // If not covered above, like for example items out of `impl` blocks, fallback. + return Ok((self, false)); + } + self.write_str(get_local_name(&self, symbol, def_id, key).as_str())?; + return Ok((self, true)); + } + Ok((self, false)) + } + /// Try to see if this path can be trimmed to a unique symbol name. fn try_print_trimmed_def_path( mut self, def_id: DefId, ) -> Result<(Self::Path, bool), Self::Error> { + if FORCE_TRIMMED_PATH.with(|flag| flag.get()) { + let (s, trimmed) = self.force_print_trimmed_def_path(def_id)?; + if trimmed { + return Ok((s, true)); + } + self = s; + } if !self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never) || NO_TRIMMED_PATH.with(|flag| flag.get()) @@ -311,7 +393,7 @@ pub trait PrettyPrinter<'tcx>: match self.tcx().trimmed_def_paths(()).get(&def_id) { None => Ok((self, false)), Some(symbol) => { - self.write_str(symbol.as_str())?; + write!(self, "{}", Ident::with_dummy_span(*symbol))?; Ok((self, true)) } } @@ -639,17 +721,17 @@ pub trait PrettyPrinter<'tcx>: ty::Foreign(def_id) => { p!(print_def_path(def_id, &[])); } - ty::Projection(ref data) => { + ty::Alias(ty::Projection, ref data) => { if !(self.should_print_verbose() || NO_QUERIES.with(|q| q.get())) - && self.tcx().def_kind(data.item_def_id) == DefKind::ImplTraitPlaceholder + && self.tcx().def_kind(data.def_id) == DefKind::ImplTraitPlaceholder { - return self.pretty_print_opaque_impl_type(data.item_def_id, data.substs); + return self.pretty_print_opaque_impl_type(data.def_id, data.substs); } else { p!(print(data)) } } ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)), - ty::Opaque(def_id, substs) => { + ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => { // FIXME(eddyb) print this with `print_def_path`. // We use verbose printing in 'NO_QUERIES' mode, to // avoid needing to call `predicates_of`. This should @@ -664,7 +746,9 @@ pub trait PrettyPrinter<'tcx>: let parent = self.tcx().parent(def_id); match self.tcx().def_kind(parent) { DefKind::TyAlias | DefKind::AssocTy => { - if let ty::Opaque(d, _) = *self.tcx().type_of(parent).kind() { + if let ty::Alias(ty::Opaque, ty::AliasTy { def_id: d, .. }) = + *self.tcx().type_of(parent).kind() + { if d == def_id { // If the type alias directly starts with the `impl` of the // opaque type we're printing, then skip the `::{opaque#1}`. @@ -737,11 +821,16 @@ pub trait PrettyPrinter<'tcx>: p!("@", print_def_path(did.to_def_id(), substs)); } else { let span = self.tcx().def_span(did); + let preference = if FORCE_TRIMMED_PATH.with(|flag| flag.get()) { + FileNameDisplayPreference::Short + } else { + FileNameDisplayPreference::Remapped + }; p!(write( "@{}", // This may end up in stderr diagnostics but it may also be emitted // into MIR. Hence we use the remapped path if available - self.tcx().sess.source_map().span_to_embeddable_string(span) + self.tcx().sess.source_map().span_to_string(span, preference) )); } } else { @@ -765,24 +854,7 @@ pub trait PrettyPrinter<'tcx>: } p!("]"); } - ty::Array(ty, sz) => { - p!("[", print(ty), "; "); - if self.should_print_verbose() { - p!(write("{:?}", sz)); - } else if let ty::ConstKind::Unevaluated(..) = sz.kind() { - // Do not try to evaluate unevaluated constants. If we are const evaluating an - // array length anon const, rustc will (with debug assertions) print the - // constant's path. Which will end up here again. - p!("_"); - } else if let Some(n) = sz.kind().try_to_bits(self.tcx().data_layout.pointer_size) { - p!(write("{}", n)); - } else if let ty::ConstKind::Param(param) = sz.kind() { - p!(print(param)); - } else { - p!("_"); - } - p!("]") - } + ty::Array(ty, sz) => p!("[", print(ty), "; ", print(sz), "]"), ty::Slice(ty) => p!("[", print(ty), "]"), } @@ -940,8 +1012,8 @@ pub trait PrettyPrinter<'tcx>: // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks, // unless we can find out what generator return type it comes from. let term = if let Some(ty) = term.skip_binder().ty() - && let ty::Projection(proj) = ty.kind() - && let Some(assoc) = tcx.opt_associated_item(proj.item_def_id) + && let ty::Alias(ty::Projection, proj) = ty.kind() + && let Some(assoc) = tcx.opt_associated_item(proj.def_id) && assoc.trait_container(tcx) == tcx.lang_items().gen_trait() && assoc.name == rustc_span::sym::Return { @@ -1214,21 +1286,25 @@ pub trait PrettyPrinter<'tcx>: match ct.kind() { ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs }) => { match self.tcx().def_kind(def.did) { - DefKind::Static(..) | DefKind::Const | DefKind::AssocConst => { + DefKind::Const | DefKind::AssocConst => { p!(print_value_path(def.did, substs)) } - _ => { - if def.is_local() { - let span = self.tcx().def_span(def.did); - if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) { - p!(write("{}", snip)) - } else { - print_underscore!() - } + DefKind::AnonConst => { + if def.is_local() + && let span = self.tcx().def_span(def.did) + && let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) + { + p!(write("{}", snip)) } else { - print_underscore!() + // Do not call `print_value_path` as if a parent of this anon const is an impl it will + // attempt to print out the impl trait ref i.e. `<T as Trait>::{constant#0}`. This would + // cause printing to enter an infinite recursion if the anon const is in the self type i.e. + // `impl<T: Default> Default for [T; 32 - 1 - 1 - 1] {` + // where we would try to print `<[T; /* print `constant#0` again */] as Default>::{constant#0}` + p!(write("{}::{}", self.tcx().crate_name(def.did.krate), self.tcx().def_path(def.did).to_string_no_crate_verbose())) } } + defkind => bug!("`{:?}` has unexpcted defkind {:?}", ct, defkind), } } ty::ConstKind::Infer(infer_ct) => { @@ -1250,7 +1326,7 @@ pub trait PrettyPrinter<'tcx>: ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)), // FIXME(generic_const_exprs): // write out some legible representation of an abstract const? - ty::ConstKind::Expr(_) => p!("[Const Expr]"), + ty::ConstKind::Expr(_) => p!("[const expr]"), ty::ConstKind::Error(_) => p!("[const error]"), }; Ok(self) @@ -1894,6 +1970,10 @@ impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> { self.0.ty_infer_name_resolver.as_ref().and_then(|func| func(id)) } + fn reset_type_limit(&mut self) { + self.printed_type_count = 0; + } + fn const_infer_name(&self, id: ty::ConstVid<'tcx>) -> Option<Symbol> { self.0.const_infer_name_resolver.as_ref().and_then(|func| func(id)) } @@ -2039,9 +2119,9 @@ impl<'tcx> FmtPrinter<'_, 'tcx> { let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions; - // These printouts are concise. They do not contain all the information + // These printouts are concise. They do not contain all the information // the user might want to diagnose an error, but there is basically no way - // to fit that into a short string. Hence the recommendation to use + // to fit that into a short string. Hence the recommendation to use // `explain_region()` or `note_and_explain_region()`. match *region { ty::ReEarlyBound(ref data) => { @@ -2388,7 +2468,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> { if not_previously_inserted { ty.super_visit_with(self) } else { - ControlFlow::CONTINUE + ControlFlow::Continue(()) } } } @@ -2574,7 +2654,7 @@ define_print_and_forward_display! { } ty::ExistentialProjection<'tcx> { - let name = cx.tcx().associated_item(self.item_def_id).name; + let name = cx.tcx().associated_item(self.def_id).name; p!(write("{} = ", name), print(self.term)) } @@ -2635,11 +2715,15 @@ define_print_and_forward_display! { } ty::SubtypePredicate<'tcx> { - p!(print(self.a), " <: ", print(self.b)) + p!(print(self.a), " <: "); + cx.reset_type_limit(); + p!(print(self.b)) } ty::CoercePredicate<'tcx> { - p!(print(self.a), " -> ", print(self.b)) + p!(print(self.a), " -> "); + cx.reset_type_limit(); + p!(print(self.b)) } ty::TraitPredicate<'tcx> { @@ -2651,7 +2735,9 @@ define_print_and_forward_display! { } ty::ProjectionPredicate<'tcx> { - p!(print(self.projection_ty), " == ", print(self.term)) + p!(print(self.projection_ty), " == "); + cx.reset_type_limit(); + p!(print(self.term)) } ty::Term<'tcx> { @@ -2661,8 +2747,8 @@ define_print_and_forward_display! { } } - ty::ProjectionTy<'tcx> { - p!(print_def_path(self.item_def_id, self.substs)); + ty::AliasTy<'tcx> { + p!(print_def_path(self.def_id, self.substs)); } ty::ClosureKind { @@ -2796,13 +2882,19 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N /// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere. /// /// The implementation uses similar import discovery logic to that of 'use' suggestions. +/// +/// See also [`DelayDm`](rustc_error_messages::DelayDm) and [`with_no_trimmed_paths`]. fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> { let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default(); if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths { + // Trimming paths is expensive and not optimized, since we expect it to only be used for error reporting. + // // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths` // wrapper can be used to suppress this query, in exchange for full paths being formatted. - tcx.sess.delay_good_path_bug("trimmed_def_paths constructed"); + tcx.sess.delay_good_path_bug( + "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging", + ); } let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> = |