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-rw-r--r--compiler/rustc_middle/src/ty/print/mod.rs327
-rw-r--r--compiler/rustc_middle/src/ty/print/pretty.rs2789
2 files changed, 3116 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
new file mode 100644
index 000000000..d57cf8f01
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -0,0 +1,327 @@
+use crate::ty::subst::{GenericArg, Subst};
+use crate::ty::{self, DefIdTree, Ty, TyCtxt};
+
+use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::sso::SsoHashSet;
+use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
+
+// `pretty` is a separate module only for organization.
+mod pretty;
+pub use self::pretty::*;
+
+// FIXME(eddyb) false positive, the lifetime parameters are used with `P: Printer<...>`.
+#[allow(unused_lifetimes)]
+pub trait Print<'tcx, P> {
+ type Output;
+ type Error;
+
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error>;
+}
+
+/// Interface for outputting user-facing "type-system entities"
+/// (paths, types, lifetimes, constants, etc.) as a side-effect
+/// (e.g. formatting, like `PrettyPrinter` implementors do) or by
+/// constructing some alternative representation (e.g. an AST),
+/// which the associated types allow passing through the methods.
+///
+/// For pretty-printing/formatting in particular, see `PrettyPrinter`.
+//
+// FIXME(eddyb) find a better name; this is more general than "printing".
+pub trait Printer<'tcx>: Sized {
+ type Error;
+
+ type Path;
+ type Region;
+ type Type;
+ type DynExistential;
+ type Const;
+
+ fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
+
+ fn print_def_path(
+ self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ self.default_print_def_path(def_id, substs)
+ }
+
+ fn print_impl_path(
+ self,
+ impl_def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ self.default_print_impl_path(impl_def_id, substs, self_ty, trait_ref)
+ }
+
+ fn print_region(self, region: ty::Region<'tcx>) -> Result<Self::Region, Self::Error>;
+
+ fn print_type(self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error>;
+
+ fn print_dyn_existential(
+ self,
+ predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
+ ) -> Result<Self::DynExistential, Self::Error>;
+
+ fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error>;
+
+ fn path_crate(self, cnum: CrateNum) -> Result<Self::Path, Self::Error>;
+
+ fn path_qualified(
+ self,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error>;
+
+ fn path_append_impl(
+ self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ disambiguated_data: &DisambiguatedDefPathData,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error>;
+
+ fn path_append(
+ self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ disambiguated_data: &DisambiguatedDefPathData,
+ ) -> Result<Self::Path, Self::Error>;
+
+ fn path_generic_args(
+ self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ args: &[GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error>;
+
+ // Defaults (should not be overridden):
+
+ #[instrument(skip(self), level = "debug")]
+ fn default_print_def_path(
+ self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ let key = self.tcx().def_key(def_id);
+ debug!(?key);
+
+ match key.disambiguated_data.data {
+ DefPathData::CrateRoot => {
+ assert!(key.parent.is_none());
+ self.path_crate(def_id.krate)
+ }
+
+ DefPathData::Impl => {
+ let generics = self.tcx().generics_of(def_id);
+ let self_ty = self.tcx().bound_type_of(def_id);
+ let impl_trait_ref = self.tcx().bound_impl_trait_ref(def_id);
+ let (self_ty, impl_trait_ref) = if substs.len() >= generics.count() {
+ (
+ self_ty.subst(self.tcx(), substs),
+ impl_trait_ref.map(|i| i.subst(self.tcx(), substs)),
+ )
+ } else {
+ (self_ty.0, impl_trait_ref.map(|i| i.0))
+ };
+ self.print_impl_path(def_id, substs, self_ty, impl_trait_ref)
+ }
+
+ _ => {
+ let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
+
+ let mut parent_substs = substs;
+ let mut trait_qualify_parent = false;
+ if !substs.is_empty() {
+ let generics = self.tcx().generics_of(def_id);
+ parent_substs = &substs[..generics.parent_count.min(substs.len())];
+
+ match key.disambiguated_data.data {
+ // Closures' own generics are only captures, don't print them.
+ DefPathData::ClosureExpr => {}
+ // This covers both `DefKind::AnonConst` and `DefKind::InlineConst`.
+ // Anon consts doesn't have their own generics, and inline consts' own
+ // generics are their inferred types, so don't print them.
+ DefPathData::AnonConst => {}
+
+ // If we have any generic arguments to print, we do that
+ // on top of the same path, but without its own generics.
+ _ => {
+ if !generics.params.is_empty() && substs.len() >= generics.count() {
+ let args = generics.own_substs_no_defaults(self.tcx(), substs);
+ return self.path_generic_args(
+ |cx| cx.print_def_path(def_id, parent_substs),
+ args,
+ );
+ }
+ }
+ }
+
+ // FIXME(eddyb) try to move this into the parent's printing
+ // logic, instead of doing it when printing the child.
+ trait_qualify_parent = generics.has_self
+ && generics.parent == Some(parent_def_id)
+ && parent_substs.len() == generics.parent_count
+ && self.tcx().generics_of(parent_def_id).parent_count == 0;
+ }
+
+ self.path_append(
+ |cx: Self| {
+ if trait_qualify_parent {
+ let trait_ref = ty::TraitRef::new(
+ parent_def_id,
+ cx.tcx().intern_substs(parent_substs),
+ );
+ cx.path_qualified(trait_ref.self_ty(), Some(trait_ref))
+ } else {
+ cx.print_def_path(parent_def_id, parent_substs)
+ }
+ },
+ &key.disambiguated_data,
+ )
+ }
+ }
+ }
+
+ fn default_print_impl_path(
+ self,
+ impl_def_id: DefId,
+ _substs: &'tcx [GenericArg<'tcx>],
+ self_ty: Ty<'tcx>,
+ impl_trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ debug!(
+ "default_print_impl_path: impl_def_id={:?}, self_ty={}, impl_trait_ref={:?}",
+ impl_def_id, self_ty, impl_trait_ref
+ );
+
+ let key = self.tcx().def_key(impl_def_id);
+ let parent_def_id = DefId { index: key.parent.unwrap(), ..impl_def_id };
+
+ // Decide whether to print the parent path for the impl.
+ // Logically, since impls are global, it's never needed, but
+ // users may find it useful. Currently, we omit the parent if
+ // the impl is either in the same module as the self-type or
+ // as the trait.
+ let in_self_mod = match characteristic_def_id_of_type(self_ty) {
+ None => false,
+ Some(ty_def_id) => self.tcx().parent(ty_def_id) == parent_def_id,
+ };
+ let in_trait_mod = match impl_trait_ref {
+ None => false,
+ Some(trait_ref) => self.tcx().parent(trait_ref.def_id) == parent_def_id,
+ };
+
+ if !in_self_mod && !in_trait_mod {
+ // If the impl is not co-located with either self-type or
+ // trait-type, then fallback to a format that identifies
+ // the module more clearly.
+ self.path_append_impl(
+ |cx| cx.print_def_path(parent_def_id, &[]),
+ &key.disambiguated_data,
+ self_ty,
+ impl_trait_ref,
+ )
+ } else {
+ // Otherwise, try to give a good form that would be valid language
+ // syntax. Preferably using associated item notation.
+ self.path_qualified(self_ty, impl_trait_ref)
+ }
+ }
+}
+
+/// As a heuristic, when we see an impl, if we see that the
+/// 'self type' is a type defined in the same module as the impl,
+/// we can omit including the path to the impl itself. This
+/// function tries to find a "characteristic `DefId`" for a
+/// type. It's just a heuristic so it makes some questionable
+/// decisions and we may want to adjust it later.
+///
+/// Visited set is needed to avoid full iteration over
+/// deeply nested tuples that have no DefId.
+fn characteristic_def_id_of_type_cached<'a>(
+ ty: Ty<'a>,
+ visited: &mut SsoHashSet<Ty<'a>>,
+) -> Option<DefId> {
+ match *ty.kind() {
+ ty::Adt(adt_def, _) => Some(adt_def.did()),
+
+ ty::Dynamic(data, ..) => data.principal_def_id(),
+
+ ty::Array(subty, _) | ty::Slice(subty) => {
+ characteristic_def_id_of_type_cached(subty, visited)
+ }
+
+ ty::RawPtr(mt) => characteristic_def_id_of_type_cached(mt.ty, visited),
+
+ ty::Ref(_, ty, _) => characteristic_def_id_of_type_cached(ty, visited),
+
+ ty::Tuple(ref tys) => tys.iter().find_map(|ty| {
+ if visited.insert(ty) {
+ return characteristic_def_id_of_type_cached(ty, visited);
+ }
+ return None;
+ }),
+
+ ty::FnDef(def_id, _)
+ | ty::Closure(def_id, _)
+ | ty::Generator(def_id, _, _)
+ | ty::Foreign(def_id) => Some(def_id),
+
+ ty::Bool
+ | ty::Char
+ | ty::Int(_)
+ | ty::Uint(_)
+ | ty::Str
+ | ty::FnPtr(_)
+ | ty::Projection(_)
+ | ty::Placeholder(..)
+ | ty::Param(_)
+ | ty::Opaque(..)
+ | ty::Infer(_)
+ | ty::Bound(..)
+ | ty::Error(_)
+ | ty::GeneratorWitness(..)
+ | ty::Never
+ | ty::Float(_) => None,
+ }
+}
+pub fn characteristic_def_id_of_type(ty: Ty<'_>) -> Option<DefId> {
+ characteristic_def_id_of_type_cached(ty, &mut SsoHashSet::new())
+}
+
+impl<'tcx, P: Printer<'tcx>> Print<'tcx, P> for ty::Region<'tcx> {
+ type Output = P::Region;
+ type Error = P::Error;
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
+ cx.print_region(*self)
+ }
+}
+
+impl<'tcx, P: Printer<'tcx>> Print<'tcx, P> for Ty<'tcx> {
+ type Output = P::Type;
+ type Error = P::Error;
+
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
+ cx.print_type(*self)
+ }
+}
+
+impl<'tcx, P: Printer<'tcx>> Print<'tcx, P>
+ for &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>
+{
+ type Output = P::DynExistential;
+ type Error = P::Error;
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
+ cx.print_dyn_existential(self)
+ }
+}
+
+impl<'tcx, P: Printer<'tcx>> Print<'tcx, P> for ty::Const<'tcx> {
+ type Output = P::Const;
+ type Error = P::Error;
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
+ cx.print_const(*self)
+ }
+}
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
new file mode 100644
index 000000000..7f2e81a71
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -0,0 +1,2789 @@
+use crate::mir::interpret::{AllocRange, GlobalAlloc, Pointer, Provenance, Scalar};
+use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
+use crate::ty::{
+ self, ConstInt, DefIdTree, ParamConst, ScalarInt, Term, Ty, TyCtxt, TypeFoldable,
+ TypeSuperFoldable, TypeSuperVisitable, TypeVisitable,
+};
+use rustc_apfloat::ieee::{Double, Single};
+use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
+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_session::config::TrimmedDefPaths;
+use rustc_session::cstore::{ExternCrate, ExternCrateSource};
+use rustc_span::symbol::{kw, Ident, Symbol};
+use rustc_target::abi::Size;
+use rustc_target::spec::abi::Abi;
+
+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};
+
+// `pretty` is a separate module only for organization.
+use super::*;
+
+macro_rules! p {
+ (@$lit:literal) => {
+ write!(scoped_cx!(), $lit)?
+ };
+ (@write($($data:expr),+)) => {
+ write!(scoped_cx!(), $($data),+)?
+ };
+ (@print($x:expr)) => {
+ scoped_cx!() = $x.print(scoped_cx!())?
+ };
+ (@$method:ident($($arg:expr),*)) => {
+ scoped_cx!() = scoped_cx!().$method($($arg),*)?
+ };
+ ($($elem:tt $(($($args:tt)*))?),+) => {{
+ $(p!(@ $elem $(($($args)*))?);)+
+ }};
+}
+macro_rules! define_scoped_cx {
+ ($cx:ident) => {
+ #[allow(unused_macros)]
+ macro_rules! scoped_cx {
+ () => {
+ $cx
+ };
+ }
+ };
+}
+
+thread_local! {
+ static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) };
+ static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) };
+ static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
+ static NO_QUERIES: Cell<bool> = const { Cell::new(false) };
+ static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) };
+}
+
+macro_rules! define_helper {
+ ($($(#[$a:meta])* fn $name:ident($helper:ident, $tl:ident);)+) => {
+ $(
+ #[must_use]
+ pub struct $helper(bool);
+
+ impl $helper {
+ pub fn new() -> $helper {
+ $helper($tl.with(|c| c.replace(true)))
+ }
+ }
+
+ $(#[$a])*
+ pub macro $name($e:expr) {
+ {
+ let _guard = $helper::new();
+ $e
+ }
+ }
+
+ impl Drop for $helper {
+ fn drop(&mut self) {
+ $tl.with(|c| c.set(self.0))
+ }
+ }
+ )+
+ }
+}
+
+define_helper!(
+ /// Avoids running any queries during any prints that occur
+ /// during the closure. This may alter the appearance of some
+ /// types (e.g. forcing verbose printing for opaque types).
+ /// This method is used during some queries (e.g. `explicit_item_bounds`
+ /// for opaque types), to ensure that any debug printing that
+ /// occurs during the query computation does not end up recursively
+ /// calling the same query.
+ fn with_no_queries(NoQueriesGuard, NO_QUERIES);
+ /// Force us to name impls with just the filename/line number. We
+ /// normally try to use types. But at some points, notably while printing
+ /// cycle errors, this can result in extra or suboptimal error output,
+ /// so this variable disables that check.
+ fn with_forced_impl_filename_line(ForcedImplGuard, FORCE_IMPL_FILENAME_LINE);
+ /// Adds the `crate::` prefix to paths where appropriate.
+ fn with_crate_prefix(CratePrefixGuard, SHOULD_PREFIX_WITH_CRATE);
+ /// Prevent path trimming if it is turned on. Path trimming affects `Display` impl
+ /// 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);
+ /// 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);
+);
+
+/// The "region highlights" are used to control region printing during
+/// specific error messages. When a "region highlight" is enabled, it
+/// gives an alternate way to print specific regions. For now, we
+/// always print those regions using a number, so something like "`'0`".
+///
+/// Regions not selected by the region highlight mode are presently
+/// unaffected.
+#[derive(Copy, Clone)]
+pub struct RegionHighlightMode<'tcx> {
+ tcx: TyCtxt<'tcx>,
+
+ /// If enabled, when we see the selected region, use "`'N`"
+ /// instead of the ordinary behavior.
+ highlight_regions: [Option<(ty::Region<'tcx>, usize)>; 3],
+
+ /// If enabled, when printing a "free region" that originated from
+ /// the given `ty::BoundRegionKind`, print it as "`'1`". Free regions that would ordinarily
+ /// have names print as normal.
+ ///
+ /// This is used when you have a signature like `fn foo(x: &u32,
+ /// y: &'a u32)` and we want to give a name to the region of the
+ /// reference `x`.
+ highlight_bound_region: Option<(ty::BoundRegionKind, usize)>,
+}
+
+impl<'tcx> RegionHighlightMode<'tcx> {
+ pub fn new(tcx: TyCtxt<'tcx>) -> Self {
+ Self {
+ tcx,
+ highlight_regions: Default::default(),
+ highlight_bound_region: Default::default(),
+ }
+ }
+
+ /// If `region` and `number` are both `Some`, invokes
+ /// `highlighting_region`.
+ pub fn maybe_highlighting_region(
+ &mut self,
+ region: Option<ty::Region<'tcx>>,
+ number: Option<usize>,
+ ) {
+ if let Some(k) = region {
+ if let Some(n) = number {
+ self.highlighting_region(k, n);
+ }
+ }
+ }
+
+ /// Highlights the region inference variable `vid` as `'N`.
+ pub fn highlighting_region(&mut self, region: ty::Region<'tcx>, number: usize) {
+ let num_slots = self.highlight_regions.len();
+ let first_avail_slot =
+ self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
+ bug!("can only highlight {} placeholders at a time", num_slots,)
+ });
+ *first_avail_slot = Some((region, number));
+ }
+
+ /// Convenience wrapper for `highlighting_region`.
+ pub fn highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize) {
+ self.highlighting_region(self.tcx.mk_region(ty::ReVar(vid)), number)
+ }
+
+ /// Returns `Some(n)` with the number to use for the given region, if any.
+ fn region_highlighted(&self, region: ty::Region<'tcx>) -> Option<usize> {
+ self.highlight_regions.iter().find_map(|h| match h {
+ Some((r, n)) if *r == region => Some(*n),
+ _ => None,
+ })
+ }
+
+ /// Highlight the given bound region.
+ /// We can only highlight one bound region at a time. See
+ /// the field `highlight_bound_region` for more detailed notes.
+ pub fn highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize) {
+ assert!(self.highlight_bound_region.is_none());
+ self.highlight_bound_region = Some((br, number));
+ }
+}
+
+/// Trait for printers that pretty-print using `fmt::Write` to the printer.
+pub trait PrettyPrinter<'tcx>:
+ Printer<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ > + fmt::Write
+{
+ /// Like `print_def_path` but for value paths.
+ fn print_value_path(
+ self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ self.print_def_path(def_id, substs)
+ }
+
+ fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+ {
+ value.as_ref().skip_binder().print(self)
+ }
+
+ fn wrap_binder<T, F: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
+ self,
+ value: &ty::Binder<'tcx, T>,
+ f: F,
+ ) -> Result<Self, Self::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+ {
+ f(value.as_ref().skip_binder(), self)
+ }
+
+ /// Prints comma-separated elements.
+ fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
+ {
+ if let Some(first) = elems.next() {
+ self = first.print(self)?;
+ for elem in elems {
+ self.write_str(", ")?;
+ self = elem.print(self)?;
+ }
+ }
+ Ok(self)
+ }
+
+ /// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
+ fn typed_value(
+ mut self,
+ f: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ t: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ conversion: &str,
+ ) -> Result<Self::Const, Self::Error> {
+ self.write_str("{")?;
+ self = f(self)?;
+ self.write_str(conversion)?;
+ self = t(self)?;
+ self.write_str("}")?;
+ Ok(self)
+ }
+
+ /// Prints `<...>` around what `f` prints.
+ fn generic_delimiters(
+ self,
+ f: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ ) -> Result<Self, Self::Error>;
+
+ /// Returns `true` if the region should be printed in
+ /// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
+ /// This is typically the case for all non-`'_` regions.
+ fn should_print_region(&self, region: ty::Region<'tcx>) -> bool;
+
+ // Defaults (should not be overridden):
+
+ /// If possible, this returns a global path resolving to `def_id` that is visible
+ /// from at least one local module, and returns `true`. If the crate defining `def_id` is
+ /// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
+ fn try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
+ if NO_VISIBLE_PATH.with(|flag| flag.get()) {
+ return Ok((self, false));
+ }
+
+ let mut callers = Vec::new();
+ self.try_print_visible_def_path_recur(def_id, &mut callers)
+ }
+
+ /// 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 !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())
+ || SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get())
+ {
+ return Ok((self, false));
+ }
+
+ match self.tcx().trimmed_def_paths(()).get(&def_id) {
+ None => Ok((self, false)),
+ Some(symbol) => {
+ self.write_str(symbol.as_str())?;
+ Ok((self, true))
+ }
+ }
+ }
+
+ /// Does the work of `try_print_visible_def_path`, building the
+ /// full definition path recursively before attempting to
+ /// post-process it into the valid and visible version that
+ /// accounts for re-exports.
+ ///
+ /// This method should only be called by itself or
+ /// `try_print_visible_def_path`.
+ ///
+ /// `callers` is a chain of visible_parent's leading to `def_id`,
+ /// to support cycle detection during recursion.
+ ///
+ /// This method returns false if we can't print the visible path, so
+ /// `print_def_path` can fall back on the item's real definition path.
+ fn try_print_visible_def_path_recur(
+ mut self,
+ def_id: DefId,
+ callers: &mut Vec<DefId>,
+ ) -> Result<(Self, bool), Self::Error> {
+ define_scoped_cx!(self);
+
+ debug!("try_print_visible_def_path: def_id={:?}", def_id);
+
+ // If `def_id` is a direct or injected extern crate, return the
+ // path to the crate followed by the path to the item within the crate.
+ if let Some(cnum) = def_id.as_crate_root() {
+ if cnum == LOCAL_CRATE {
+ return Ok((self.path_crate(cnum)?, true));
+ }
+
+ // In local mode, when we encounter a crate other than
+ // LOCAL_CRATE, execution proceeds in one of two ways:
+ //
+ // 1. For a direct dependency, where user added an
+ // `extern crate` manually, we put the `extern
+ // crate` as the parent. So you wind up with
+ // something relative to the current crate.
+ // 2. For an extern inferred from a path or an indirect crate,
+ // where there is no explicit `extern crate`, we just prepend
+ // the crate name.
+ match self.tcx().extern_crate(def_id) {
+ Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
+ (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
+ // NOTE(eddyb) the only reason `span` might be dummy,
+ // that we're aware of, is that it's the `std`/`core`
+ // `extern crate` injected by default.
+ // FIXME(eddyb) find something better to key this on,
+ // or avoid ending up with `ExternCrateSource::Extern`,
+ // for the injected `std`/`core`.
+ if span.is_dummy() {
+ return Ok((self.path_crate(cnum)?, true));
+ }
+
+ // Disable `try_print_trimmed_def_path` behavior within
+ // the `print_def_path` call, to avoid infinite recursion
+ // in cases where the `extern crate foo` has non-trivial
+ // parents, e.g. it's nested in `impl foo::Trait for Bar`
+ // (see also issues #55779 and #87932).
+ self = with_no_visible_paths!(self.print_def_path(def_id, &[])?);
+
+ return Ok((self, true));
+ }
+ (ExternCrateSource::Path, LOCAL_CRATE) => {
+ return Ok((self.path_crate(cnum)?, true));
+ }
+ _ => {}
+ },
+ None => {
+ return Ok((self.path_crate(cnum)?, true));
+ }
+ }
+ }
+
+ if def_id.is_local() {
+ return Ok((self, false));
+ }
+
+ let visible_parent_map = self.tcx().visible_parent_map(());
+
+ let mut cur_def_key = self.tcx().def_key(def_id);
+ debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
+
+ // For a constructor, we want the name of its parent rather than <unnamed>.
+ if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
+ let parent = DefId {
+ krate: def_id.krate,
+ index: cur_def_key
+ .parent
+ .expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
+ };
+
+ cur_def_key = self.tcx().def_key(parent);
+ }
+
+ let Some(visible_parent) = visible_parent_map.get(&def_id).cloned() else {
+ return Ok((self, false));
+ };
+
+ let actual_parent = self.tcx().opt_parent(def_id);
+ debug!(
+ "try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
+ visible_parent, actual_parent,
+ );
+
+ let mut data = cur_def_key.disambiguated_data.data;
+ debug!(
+ "try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
+ data, visible_parent, actual_parent,
+ );
+
+ match data {
+ // In order to output a path that could actually be imported (valid and visible),
+ // we need to handle re-exports correctly.
+ //
+ // For example, take `std::os::unix::process::CommandExt`, this trait is actually
+ // defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
+ //
+ // `std::os::unix` reexports the contents of `std::sys::unix::ext`. `std::sys` is
+ // private so the "true" path to `CommandExt` isn't accessible.
+ //
+ // In this case, the `visible_parent_map` will look something like this:
+ //
+ // (child) -> (parent)
+ // `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
+ // `std::sys::unix::ext::process` -> `std::sys::unix::ext`
+ // `std::sys::unix::ext` -> `std::os`
+ //
+ // This is correct, as the visible parent of `std::sys::unix::ext` is in fact
+ // `std::os`.
+ //
+ // When printing the path to `CommandExt` and looking at the `cur_def_key` that
+ // corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
+ // to the parent - resulting in a mangled path like
+ // `std::os::ext::process::CommandExt`.
+ //
+ // Instead, we must detect that there was a re-export and instead print `unix`
+ // (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
+ // do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
+ // the visible parent (`std::os`). If these do not match, then we iterate over
+ // the children of the visible parent (as was done when computing
+ // `visible_parent_map`), looking for the specific child we currently have and then
+ // have access to the re-exported name.
+ DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
+ // Item might be re-exported several times, but filter for the one
+ // that's public and whose identifier isn't `_`.
+ let reexport = self
+ .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);
+
+ if let Some(new_name) = reexport {
+ *name = new_name;
+ } else {
+ // There is no name that is public and isn't `_`, so bail.
+ return Ok((self, false));
+ }
+ }
+ // Re-exported `extern crate` (#43189).
+ DefPathData::CrateRoot => {
+ data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
+ }
+ _ => {}
+ }
+ debug!("try_print_visible_def_path: data={:?}", data);
+
+ if callers.contains(&visible_parent) {
+ return Ok((self, false));
+ }
+ callers.push(visible_parent);
+ // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
+ // knowing ahead of time whether the entire path will succeed or not.
+ // To support printers that do not implement `PrettyPrinter`, a `Vec` or
+ // linked list on the stack would need to be built, before any printing.
+ match self.try_print_visible_def_path_recur(visible_parent, callers)? {
+ (cx, false) => return Ok((cx, false)),
+ (cx, true) => self = cx,
+ }
+ callers.pop();
+
+ Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
+ }
+
+ fn pretty_path_qualified(
+ self,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ if trait_ref.is_none() {
+ // Inherent impls. Try to print `Foo::bar` for an inherent
+ // impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
+ // anything other than a simple path.
+ match self_ty.kind() {
+ ty::Adt(..)
+ | ty::Foreign(_)
+ | ty::Bool
+ | ty::Char
+ | ty::Str
+ | ty::Int(_)
+ | ty::Uint(_)
+ | ty::Float(_) => {
+ return self_ty.print(self);
+ }
+
+ _ => {}
+ }
+ }
+
+ self.generic_delimiters(|mut cx| {
+ define_scoped_cx!(cx);
+
+ p!(print(self_ty));
+ if let Some(trait_ref) = trait_ref {
+ p!(" as ", print(trait_ref.print_only_trait_path()));
+ }
+ Ok(cx)
+ })
+ }
+
+ fn pretty_path_append_impl(
+ mut self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ self = print_prefix(self)?;
+
+ self.generic_delimiters(|mut cx| {
+ define_scoped_cx!(cx);
+
+ p!("impl ");
+ if let Some(trait_ref) = trait_ref {
+ p!(print(trait_ref.print_only_trait_path()), " for ");
+ }
+ p!(print(self_ty));
+
+ Ok(cx)
+ })
+ }
+
+ fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
+ define_scoped_cx!(self);
+
+ match *ty.kind() {
+ ty::Bool => p!("bool"),
+ ty::Char => p!("char"),
+ ty::Int(t) => p!(write("{}", t.name_str())),
+ ty::Uint(t) => p!(write("{}", t.name_str())),
+ ty::Float(t) => p!(write("{}", t.name_str())),
+ ty::RawPtr(ref tm) => {
+ p!(write(
+ "*{} ",
+ match tm.mutbl {
+ hir::Mutability::Mut => "mut",
+ hir::Mutability::Not => "const",
+ }
+ ));
+ p!(print(tm.ty))
+ }
+ ty::Ref(r, ty, mutbl) => {
+ p!("&");
+ if self.should_print_region(r) {
+ p!(print(r), " ");
+ }
+ p!(print(ty::TypeAndMut { ty, mutbl }))
+ }
+ ty::Never => p!("!"),
+ ty::Tuple(ref tys) => {
+ p!("(", comma_sep(tys.iter()));
+ if tys.len() == 1 {
+ p!(",");
+ }
+ p!(")")
+ }
+ ty::FnDef(def_id, substs) => {
+ let sig = self.tcx().bound_fn_sig(def_id).subst(self.tcx(), substs);
+ p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
+ }
+ ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
+ ty::Infer(infer_ty) => {
+ let verbose = self.tcx().sess.verbose();
+ if let ty::TyVar(ty_vid) = infer_ty {
+ if let Some(name) = self.ty_infer_name(ty_vid) {
+ p!(write("{}", name))
+ } else {
+ if verbose {
+ p!(write("{:?}", infer_ty))
+ } else {
+ p!(write("{}", infer_ty))
+ }
+ }
+ } else {
+ if verbose { p!(write("{:?}", infer_ty)) } else { p!(write("{}", infer_ty)) }
+ }
+ }
+ ty::Error(_) => p!("[type error]"),
+ ty::Param(ref param_ty) => p!(print(param_ty)),
+ ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
+ ty::BoundTyKind::Anon => self.pretty_print_bound_var(debruijn, bound_ty.var)?,
+ ty::BoundTyKind::Param(p) => p!(write("{}", p)),
+ },
+ ty::Adt(def, substs) => {
+ p!(print_def_path(def.did(), substs));
+ }
+ ty::Dynamic(data, r) => {
+ let print_r = self.should_print_region(r);
+ if print_r {
+ p!("(");
+ }
+ p!("dyn ", print(data));
+ if print_r {
+ p!(" + ", print(r), ")");
+ }
+ }
+ ty::Foreign(def_id) => {
+ p!(print_def_path(def_id, &[]));
+ }
+ ty::Projection(ref data) => p!(print(data)),
+ ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
+ ty::Opaque(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
+ // only affect certain debug messages (e.g. messages printed
+ // from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
+ // and should have no effect on any compiler output.
+ if self.tcx().sess.verbose() || NO_QUERIES.with(|q| q.get()) {
+ p!(write("Opaque({:?}, {:?})", def_id, substs));
+ return Ok(self);
+ }
+
+ 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 d == def_id {
+ // If the type alias directly starts with the `impl` of the
+ // opaque type we're printing, then skip the `::{opaque#1}`.
+ p!(print_def_path(parent, substs));
+ return Ok(self);
+ }
+ }
+ // Complex opaque type, e.g. `type Foo = (i32, impl Debug);`
+ p!(print_def_path(def_id, substs));
+ return Ok(self);
+ }
+ _ => return self.pretty_print_opaque_impl_type(def_id, substs),
+ }
+ }
+ ty::Str => p!("str"),
+ ty::Generator(did, substs, movability) => {
+ p!(write("["));
+ match movability {
+ hir::Movability::Movable => {}
+ hir::Movability::Static => p!("static "),
+ }
+
+ if !self.tcx().sess.verbose() {
+ p!("generator");
+ // FIXME(eddyb) should use `def_span`.
+ if let Some(did) = did.as_local() {
+ let span = self.tcx().def_span(did);
+ 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)
+ ));
+ } else {
+ p!(write("@"), print_def_path(did, substs));
+ }
+ } else {
+ p!(print_def_path(did, substs));
+ p!(" upvar_tys=(");
+ if !substs.as_generator().is_valid() {
+ p!("unavailable");
+ } else {
+ self = self.comma_sep(substs.as_generator().upvar_tys())?;
+ }
+ p!(")");
+
+ if substs.as_generator().is_valid() {
+ p!(" ", print(substs.as_generator().witness()));
+ }
+ }
+
+ p!("]")
+ }
+ ty::GeneratorWitness(types) => {
+ p!(in_binder(&types));
+ }
+ ty::Closure(did, substs) => {
+ p!(write("["));
+ if !self.tcx().sess.verbose() {
+ p!(write("closure"));
+ // FIXME(eddyb) should use `def_span`.
+ if let Some(did) = did.as_local() {
+ if self.tcx().sess.opts.unstable_opts.span_free_formats {
+ p!("@", print_def_path(did.to_def_id(), substs));
+ } else {
+ let span = self.tcx().def_span(did);
+ 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)
+ ));
+ }
+ } else {
+ p!(write("@"), print_def_path(did, substs));
+ }
+ } else {
+ p!(print_def_path(did, substs));
+ if !substs.as_closure().is_valid() {
+ p!(" closure_substs=(unavailable)");
+ p!(write(" substs={:?}", substs));
+ } else {
+ p!(" closure_kind_ty=", print(substs.as_closure().kind_ty()));
+ p!(
+ " closure_sig_as_fn_ptr_ty=",
+ print(substs.as_closure().sig_as_fn_ptr_ty())
+ );
+ p!(" upvar_tys=(");
+ self = self.comma_sep(substs.as_closure().upvar_tys())?;
+ p!(")");
+ }
+ }
+ p!("]");
+ }
+ ty::Array(ty, sz) => {
+ p!("[", print(ty), "; ");
+ if self.tcx().sess.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::Slice(ty) => p!("[", print(ty), "]"),
+ }
+
+ Ok(self)
+ }
+
+ fn pretty_print_opaque_impl_type(
+ mut self,
+ def_id: DefId,
+ substs: &'tcx ty::List<ty::GenericArg<'tcx>>,
+ ) -> Result<Self::Type, Self::Error> {
+ let tcx = self.tcx();
+
+ // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
+ // by looking up the projections associated with the def_id.
+ let bounds = tcx.bound_explicit_item_bounds(def_id);
+
+ let mut traits = FxIndexMap::default();
+ let mut fn_traits = FxIndexMap::default();
+ let mut is_sized = false;
+
+ for predicate in bounds.transpose_iter().map(|e| e.map_bound(|(p, _)| *p)) {
+ let predicate = predicate.subst(tcx, substs);
+ let bound_predicate = predicate.kind();
+
+ match bound_predicate.skip_binder() {
+ ty::PredicateKind::Trait(pred) => {
+ let trait_ref = bound_predicate.rebind(pred.trait_ref);
+
+ // Don't print + Sized, but rather + ?Sized if absent.
+ if Some(trait_ref.def_id()) == tcx.lang_items().sized_trait() {
+ is_sized = true;
+ continue;
+ }
+
+ self.insert_trait_and_projection(trait_ref, None, &mut traits, &mut fn_traits);
+ }
+ ty::PredicateKind::Projection(pred) => {
+ let proj_ref = bound_predicate.rebind(pred);
+ let trait_ref = proj_ref.required_poly_trait_ref(tcx);
+
+ // Projection type entry -- the def-id for naming, and the ty.
+ let proj_ty = (proj_ref.projection_def_id(), proj_ref.term());
+
+ self.insert_trait_and_projection(
+ trait_ref,
+ Some(proj_ty),
+ &mut traits,
+ &mut fn_traits,
+ );
+ }
+ _ => {}
+ }
+ }
+
+ write!(self, "impl ")?;
+
+ let mut first = true;
+ // Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
+ let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !is_sized;
+
+ for (fn_once_trait_ref, entry) in fn_traits {
+ write!(self, "{}", if first { "" } else { " + " })?;
+ write!(self, "{}", if paren_needed { "(" } else { "" })?;
+
+ self = self.wrap_binder(&fn_once_trait_ref, |trait_ref, mut cx| {
+ define_scoped_cx!(cx);
+ // Get the (single) generic ty (the args) of this FnOnce trait ref.
+ let generics = tcx.generics_of(trait_ref.def_id);
+ let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
+
+ match (entry.return_ty, args[0].expect_ty()) {
+ // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
+ // a return type.
+ (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
+ let name = if entry.fn_trait_ref.is_some() {
+ "Fn"
+ } else if entry.fn_mut_trait_ref.is_some() {
+ "FnMut"
+ } else {
+ "FnOnce"
+ };
+
+ p!(write("{}(", name));
+
+ for (idx, ty) in arg_tys.tuple_fields().iter().enumerate() {
+ if idx > 0 {
+ p!(", ");
+ }
+ p!(print(ty));
+ }
+
+ p!(")");
+ if let Term::Ty(ty) = return_ty.skip_binder() {
+ if !ty.is_unit() {
+ p!(" -> ", print(return_ty));
+ }
+ }
+ p!(write("{}", if paren_needed { ")" } else { "" }));
+
+ first = false;
+ }
+ // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
+ // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
+ _ => {
+ if entry.has_fn_once {
+ traits.entry(fn_once_trait_ref).or_default().extend(
+ // Group the return ty with its def id, if we had one.
+ entry
+ .return_ty
+ .map(|ty| (tcx.lang_items().fn_once_output().unwrap(), ty)),
+ );
+ }
+ if let Some(trait_ref) = entry.fn_mut_trait_ref {
+ traits.entry(trait_ref).or_default();
+ }
+ if let Some(trait_ref) = entry.fn_trait_ref {
+ traits.entry(trait_ref).or_default();
+ }
+ }
+ }
+
+ Ok(cx)
+ })?;
+ }
+
+ // Print the rest of the trait types (that aren't Fn* family of traits)
+ for (trait_ref, assoc_items) in traits {
+ write!(self, "{}", if first { "" } else { " + " })?;
+
+ self = self.wrap_binder(&trait_ref, |trait_ref, mut cx| {
+ define_scoped_cx!(cx);
+ p!(print(trait_ref.print_only_trait_name()));
+
+ let generics = tcx.generics_of(trait_ref.def_id);
+ let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
+
+ if !args.is_empty() || !assoc_items.is_empty() {
+ let mut first = true;
+
+ for ty in args {
+ if first {
+ p!("<");
+ first = false;
+ } else {
+ p!(", ");
+ }
+ p!(print(ty));
+ }
+
+ for (assoc_item_def_id, term) in assoc_items {
+ // 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(ty::ProjectionTy { item_def_id, substs }) = ty.kind()
+ && Some(*item_def_id) == tcx.lang_items().generator_return()
+ {
+ if let ty::Generator(_, substs, _) = substs.type_at(0).kind() {
+ let return_ty = substs.as_generator().return_ty();
+ if !return_ty.is_ty_infer() {
+ return_ty.into()
+ } else {
+ continue;
+ }
+ } else {
+ continue;
+ }
+ } else {
+ term.skip_binder()
+ };
+
+ if first {
+ p!("<");
+ first = false;
+ } else {
+ p!(", ");
+ }
+
+ p!(write("{} = ", tcx.associated_item(assoc_item_def_id).name));
+
+ match term {
+ Term::Ty(ty) => {
+ p!(print(ty))
+ }
+ Term::Const(c) => {
+ p!(print(c));
+ }
+ };
+ }
+
+ if !first {
+ p!(">");
+ }
+ }
+
+ first = false;
+ Ok(cx)
+ })?;
+ }
+
+ if !is_sized {
+ write!(self, "{}?Sized", if first { "" } else { " + " })?;
+ } else if first {
+ write!(self, "Sized")?;
+ }
+
+ Ok(self)
+ }
+
+ /// Insert the trait ref and optionally a projection type associated with it into either the
+ /// traits map or fn_traits map, depending on if the trait is in the Fn* family of traits.
+ fn insert_trait_and_projection(
+ &mut self,
+ trait_ref: ty::PolyTraitRef<'tcx>,
+ proj_ty: Option<(DefId, ty::Binder<'tcx, Term<'tcx>>)>,
+ traits: &mut FxIndexMap<
+ ty::PolyTraitRef<'tcx>,
+ FxIndexMap<DefId, ty::Binder<'tcx, Term<'tcx>>>,
+ >,
+ fn_traits: &mut FxIndexMap<ty::PolyTraitRef<'tcx>, OpaqueFnEntry<'tcx>>,
+ ) {
+ let trait_def_id = trait_ref.def_id();
+
+ // If our trait_ref is FnOnce or any of its children, project it onto the parent FnOnce
+ // super-trait ref and record it there.
+ if let Some(fn_once_trait) = self.tcx().lang_items().fn_once_trait() {
+ // If we have a FnOnce, then insert it into
+ if trait_def_id == fn_once_trait {
+ let entry = fn_traits.entry(trait_ref).or_default();
+ // Optionally insert the return_ty as well.
+ if let Some((_, ty)) = proj_ty {
+ entry.return_ty = Some(ty);
+ }
+ entry.has_fn_once = true;
+ return;
+ } else if Some(trait_def_id) == self.tcx().lang_items().fn_mut_trait() {
+ let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
+ .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
+ .unwrap();
+
+ fn_traits.entry(super_trait_ref).or_default().fn_mut_trait_ref = Some(trait_ref);
+ return;
+ } else if Some(trait_def_id) == self.tcx().lang_items().fn_trait() {
+ let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
+ .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
+ .unwrap();
+
+ fn_traits.entry(super_trait_ref).or_default().fn_trait_ref = Some(trait_ref);
+ return;
+ }
+ }
+
+ // Otherwise, just group our traits and projection types.
+ traits.entry(trait_ref).or_default().extend(proj_ty);
+ }
+
+ fn pretty_print_bound_var(
+ &mut self,
+ debruijn: ty::DebruijnIndex,
+ var: ty::BoundVar,
+ ) -> Result<(), Self::Error> {
+ if debruijn == ty::INNERMOST {
+ write!(self, "^{}", var.index())
+ } else {
+ write!(self, "^{}_{}", debruijn.index(), var.index())
+ }
+ }
+
+ fn ty_infer_name(&self, _: ty::TyVid) -> Option<Symbol> {
+ None
+ }
+
+ fn const_infer_name(&self, _: ty::ConstVid<'tcx>) -> Option<Symbol> {
+ None
+ }
+
+ fn pretty_print_dyn_existential(
+ mut self,
+ predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
+ ) -> Result<Self::DynExistential, Self::Error> {
+ // Generate the main trait ref, including associated types.
+ let mut first = true;
+
+ if let Some(principal) = predicates.principal() {
+ self = self.wrap_binder(&principal, |principal, mut cx| {
+ define_scoped_cx!(cx);
+ p!(print_def_path(principal.def_id, &[]));
+
+ let mut resugared = false;
+
+ // Special-case `Fn(...) -> ...` and re-sugar it.
+ let fn_trait_kind = cx.tcx().fn_trait_kind_from_lang_item(principal.def_id);
+ if !cx.tcx().sess.verbose() && fn_trait_kind.is_some() {
+ if let ty::Tuple(tys) = principal.substs.type_at(0).kind() {
+ let mut projections = predicates.projection_bounds();
+ if let (Some(proj), None) = (projections.next(), projections.next()) {
+ p!(pretty_fn_sig(
+ tys,
+ false,
+ proj.skip_binder().term.ty().expect("Return type was a const")
+ ));
+ resugared = true;
+ }
+ }
+ }
+
+ // HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
+ // in order to place the projections inside the `<...>`.
+ if !resugared {
+ // Use a type that can't appear in defaults of type parameters.
+ let dummy_cx = cx.tcx().mk_ty_infer(ty::FreshTy(0));
+ let principal = principal.with_self_ty(cx.tcx(), dummy_cx);
+
+ let args = cx
+ .tcx()
+ .generics_of(principal.def_id)
+ .own_substs_no_defaults(cx.tcx(), principal.substs);
+
+ // Don't print `'_` if there's no unerased regions.
+ let print_regions = args.iter().any(|arg| match arg.unpack() {
+ GenericArgKind::Lifetime(r) => !r.is_erased(),
+ _ => false,
+ });
+ let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
+ GenericArgKind::Lifetime(_) => print_regions,
+ _ => true,
+ });
+ let mut projections = predicates.projection_bounds();
+
+ let arg0 = args.next();
+ let projection0 = projections.next();
+ if arg0.is_some() || projection0.is_some() {
+ let args = arg0.into_iter().chain(args);
+ let projections = projection0.into_iter().chain(projections);
+
+ p!(generic_delimiters(|mut cx| {
+ cx = cx.comma_sep(args)?;
+ if arg0.is_some() && projection0.is_some() {
+ write!(cx, ", ")?;
+ }
+ cx.comma_sep(projections)
+ }));
+ }
+ }
+ Ok(cx)
+ })?;
+
+ first = false;
+ }
+
+ define_scoped_cx!(self);
+
+ // Builtin bounds.
+ // FIXME(eddyb) avoid printing twice (needed to ensure
+ // that the auto traits are sorted *and* printed via cx).
+ let mut auto_traits: Vec<_> = predicates.auto_traits().collect();
+
+ // The auto traits come ordered by `DefPathHash`. While
+ // `DefPathHash` is *stable* in the sense that it depends on
+ // neither the host nor the phase of the moon, it depends
+ // "pseudorandomly" on the compiler version and the target.
+ //
+ // To avoid causing instabilities in compiletest
+ // output, sort the auto-traits alphabetically.
+ auto_traits.sort_by_cached_key(|did| self.tcx().def_path_str(*did));
+
+ for def_id in auto_traits {
+ if !first {
+ p!(" + ");
+ }
+ first = false;
+
+ p!(print_def_path(def_id, &[]));
+ }
+
+ Ok(self)
+ }
+
+ fn pretty_fn_sig(
+ mut self,
+ inputs: &[Ty<'tcx>],
+ c_variadic: bool,
+ output: Ty<'tcx>,
+ ) -> Result<Self, Self::Error> {
+ define_scoped_cx!(self);
+
+ p!("(", comma_sep(inputs.iter().copied()));
+ if c_variadic {
+ if !inputs.is_empty() {
+ p!(", ");
+ }
+ p!("...");
+ }
+ p!(")");
+ if !output.is_unit() {
+ p!(" -> ", print(output));
+ }
+
+ Ok(self)
+ }
+
+ fn pretty_print_const(
+ mut self,
+ ct: ty::Const<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ define_scoped_cx!(self);
+
+ if self.tcx().sess.verbose() {
+ p!(write("Const({:?}: {:?})", ct.kind(), ct.ty()));
+ return Ok(self);
+ }
+
+ macro_rules! print_underscore {
+ () => {{
+ if print_ty {
+ self = self.typed_value(
+ |mut this| {
+ write!(this, "_")?;
+ Ok(this)
+ },
+ |this| this.print_type(ct.ty()),
+ ": ",
+ )?;
+ } else {
+ write!(self, "_")?;
+ }
+ }};
+ }
+
+ match ct.kind() {
+ ty::ConstKind::Unevaluated(ty::Unevaluated {
+ def,
+ substs,
+ promoted: Some(promoted),
+ }) => {
+ p!(print_value_path(def.did, substs));
+ p!(write("::{:?}", promoted));
+ }
+ ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted: None }) => {
+ match self.tcx().def_kind(def.did) {
+ DefKind::Static(..) | 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!()
+ }
+ } else {
+ print_underscore!()
+ }
+ }
+ }
+ }
+ ty::ConstKind::Infer(infer_ct) => {
+ match infer_ct {
+ ty::InferConst::Var(ct_vid)
+ if let Some(name) = self.const_infer_name(ct_vid) =>
+ p!(write("{}", name)),
+ _ => print_underscore!(),
+ }
+ }
+ ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
+ ty::ConstKind::Value(value) => {
+ return self.pretty_print_const_valtree(value, ct.ty(), print_ty);
+ }
+
+ ty::ConstKind::Bound(debruijn, bound_var) => {
+ self.pretty_print_bound_var(debruijn, bound_var)?
+ }
+ ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
+ ty::ConstKind::Error(_) => p!("[const error]"),
+ };
+ Ok(self)
+ }
+
+ fn pretty_print_const_scalar(
+ self,
+ scalar: Scalar,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ match scalar {
+ Scalar::Ptr(ptr, _size) => self.pretty_print_const_scalar_ptr(ptr, ty, print_ty),
+ Scalar::Int(int) => self.pretty_print_const_scalar_int(int, ty, print_ty),
+ }
+ }
+
+ fn pretty_print_const_scalar_ptr(
+ mut self,
+ ptr: Pointer,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ define_scoped_cx!(self);
+
+ let (alloc_id, offset) = ptr.into_parts();
+ match ty.kind() {
+ // Byte strings (&[u8; N])
+ ty::Ref(_, inner, _) => {
+ if let ty::Array(elem, len) = inner.kind() {
+ if let ty::Uint(ty::UintTy::U8) = elem.kind() {
+ if let ty::ConstKind::Value(ty::ValTree::Leaf(int)) = len.kind() {
+ match self.tcx().try_get_global_alloc(alloc_id) {
+ Some(GlobalAlloc::Memory(alloc)) => {
+ let len = int.assert_bits(self.tcx().data_layout.pointer_size);
+ let range =
+ AllocRange { start: offset, size: Size::from_bytes(len) };
+ if let Ok(byte_str) =
+ alloc.inner().get_bytes(&self.tcx(), range)
+ {
+ p!(pretty_print_byte_str(byte_str))
+ } else {
+ p!("<too short allocation>")
+ }
+ }
+ // FIXME: for statics, vtables, and functions, we could in principle print more detail.
+ Some(GlobalAlloc::Static(def_id)) => {
+ p!(write("<static({:?})>", def_id))
+ }
+ Some(GlobalAlloc::Function(_)) => p!("<function>"),
+ Some(GlobalAlloc::VTable(..)) => p!("<vtable>"),
+ None => p!("<dangling pointer>"),
+ }
+ return Ok(self);
+ }
+ }
+ }
+ }
+ ty::FnPtr(_) => {
+ // FIXME: We should probably have a helper method to share code with the "Byte strings"
+ // printing above (which also has to handle pointers to all sorts of things).
+ if let Some(GlobalAlloc::Function(instance)) =
+ self.tcx().try_get_global_alloc(alloc_id)
+ {
+ self = self.typed_value(
+ |this| this.print_value_path(instance.def_id(), instance.substs),
+ |this| this.print_type(ty),
+ " as ",
+ )?;
+ return Ok(self);
+ }
+ }
+ _ => {}
+ }
+ // Any pointer values not covered by a branch above
+ self = self.pretty_print_const_pointer(ptr, ty, print_ty)?;
+ Ok(self)
+ }
+
+ fn pretty_print_const_scalar_int(
+ mut self,
+ int: ScalarInt,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ define_scoped_cx!(self);
+
+ match ty.kind() {
+ // Bool
+ ty::Bool if int == ScalarInt::FALSE => p!("false"),
+ ty::Bool if int == ScalarInt::TRUE => p!("true"),
+ // Float
+ ty::Float(ty::FloatTy::F32) => {
+ p!(write("{}f32", Single::try_from(int).unwrap()))
+ }
+ ty::Float(ty::FloatTy::F64) => {
+ p!(write("{}f64", Double::try_from(int).unwrap()))
+ }
+ // Int
+ ty::Uint(_) | ty::Int(_) => {
+ let int =
+ ConstInt::new(int, matches!(ty.kind(), ty::Int(_)), ty.is_ptr_sized_integral());
+ if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
+ }
+ // Char
+ ty::Char if char::try_from(int).is_ok() => {
+ p!(write("{:?}", char::try_from(int).unwrap()))
+ }
+ // Pointer types
+ ty::Ref(..) | ty::RawPtr(_) | ty::FnPtr(_) => {
+ let data = int.assert_bits(self.tcx().data_layout.pointer_size);
+ self = self.typed_value(
+ |mut this| {
+ write!(this, "0x{:x}", data)?;
+ Ok(this)
+ },
+ |this| this.print_type(ty),
+ " as ",
+ )?;
+ }
+ // Nontrivial types with scalar bit representation
+ _ => {
+ let print = |mut this: Self| {
+ if int.size() == Size::ZERO {
+ write!(this, "transmute(())")?;
+ } else {
+ write!(this, "transmute(0x{:x})", int)?;
+ }
+ Ok(this)
+ };
+ self = if print_ty {
+ self.typed_value(print, |this| this.print_type(ty), ": ")?
+ } else {
+ print(self)?
+ };
+ }
+ }
+ Ok(self)
+ }
+
+ /// This is overridden for MIR printing because we only want to hide alloc ids from users, not
+ /// from MIR where it is actually useful.
+ fn pretty_print_const_pointer<Prov: Provenance>(
+ mut self,
+ _: Pointer<Prov>,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ if print_ty {
+ self.typed_value(
+ |mut this| {
+ this.write_str("&_")?;
+ Ok(this)
+ },
+ |this| this.print_type(ty),
+ ": ",
+ )
+ } else {
+ self.write_str("&_")?;
+ Ok(self)
+ }
+ }
+
+ fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
+ define_scoped_cx!(self);
+ p!("b\"");
+ for &c in byte_str {
+ for e in std::ascii::escape_default(c) {
+ self.write_char(e as char)?;
+ }
+ }
+ p!("\"");
+ Ok(self)
+ }
+
+ fn pretty_print_const_valtree(
+ mut self,
+ valtree: ty::ValTree<'tcx>,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ define_scoped_cx!(self);
+
+ if self.tcx().sess.verbose() {
+ p!(write("ValTree({:?}: ", valtree), print(ty), ")");
+ return Ok(self);
+ }
+
+ let u8_type = self.tcx().types.u8;
+ match (valtree, ty.kind()) {
+ (ty::ValTree::Branch(_), ty::Ref(_, inner_ty, _)) => match inner_ty.kind() {
+ ty::Slice(t) if *t == u8_type => {
+ let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
+ bug!(
+ "expected to convert valtree {:?} to raw bytes for type {:?}",
+ valtree,
+ t
+ )
+ });
+ return self.pretty_print_byte_str(bytes);
+ }
+ ty::Str => {
+ let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
+ bug!("expected to convert valtree to raw bytes for type {:?}", ty)
+ });
+ p!(write("{:?}", String::from_utf8_lossy(bytes)));
+ return Ok(self);
+ }
+ _ => {
+ p!("&");
+ p!(pretty_print_const_valtree(valtree, *inner_ty, print_ty));
+ return Ok(self);
+ }
+ },
+ (ty::ValTree::Branch(_), ty::Array(t, _)) if *t == u8_type => {
+ let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
+ bug!("expected to convert valtree to raw bytes for type {:?}", t)
+ });
+ p!("*");
+ p!(pretty_print_byte_str(bytes));
+ return Ok(self);
+ }
+ // Aggregates, printed as array/tuple/struct/variant construction syntax.
+ (ty::ValTree::Branch(_), ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) => {
+ let contents =
+ self.tcx().destructure_const(ty::Const::from_value(self.tcx(), valtree, ty));
+ let fields = contents.fields.iter().copied();
+ match *ty.kind() {
+ ty::Array(..) => {
+ p!("[", comma_sep(fields), "]");
+ }
+ ty::Tuple(..) => {
+ p!("(", comma_sep(fields));
+ if contents.fields.len() == 1 {
+ p!(",");
+ }
+ p!(")");
+ }
+ ty::Adt(def, _) if def.variants().is_empty() => {
+ self = self.typed_value(
+ |mut this| {
+ write!(this, "unreachable()")?;
+ Ok(this)
+ },
+ |this| this.print_type(ty),
+ ": ",
+ )?;
+ }
+ ty::Adt(def, substs) => {
+ let variant_idx =
+ contents.variant.expect("destructed const of adt without variant idx");
+ let variant_def = &def.variant(variant_idx);
+ p!(print_value_path(variant_def.def_id, substs));
+ match variant_def.ctor_kind {
+ CtorKind::Const => {}
+ CtorKind::Fn => {
+ p!("(", comma_sep(fields), ")");
+ }
+ CtorKind::Fictive => {
+ p!(" {{ ");
+ let mut first = true;
+ for (field_def, field) in iter::zip(&variant_def.fields, fields) {
+ if !first {
+ p!(", ");
+ }
+ p!(write("{}: ", field_def.name), print(field));
+ first = false;
+ }
+ p!(" }}");
+ }
+ }
+ }
+ _ => unreachable!(),
+ }
+ return Ok(self);
+ }
+ (ty::ValTree::Leaf(leaf), _) => {
+ return self.pretty_print_const_scalar_int(leaf, ty, print_ty);
+ }
+ // FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
+ // their fields instead of just dumping the memory.
+ _ => {}
+ }
+
+ // fallback
+ if valtree == ty::ValTree::zst() {
+ p!(write("<ZST>"));
+ } else {
+ p!(write("{:?}", valtree));
+ }
+ if print_ty {
+ p!(": ", print(ty));
+ }
+ Ok(self)
+ }
+}
+
+// HACK(eddyb) boxed to avoid moving around a large struct by-value.
+pub struct FmtPrinter<'a, 'tcx>(Box<FmtPrinterData<'a, 'tcx>>);
+
+pub struct FmtPrinterData<'a, 'tcx> {
+ tcx: TyCtxt<'tcx>,
+ fmt: String,
+
+ empty_path: bool,
+ in_value: bool,
+ pub print_alloc_ids: bool,
+
+ used_region_names: FxHashSet<Symbol>,
+ region_index: usize,
+ binder_depth: usize,
+ printed_type_count: usize,
+
+ pub region_highlight_mode: RegionHighlightMode<'tcx>,
+
+ pub ty_infer_name_resolver: Option<Box<dyn Fn(ty::TyVid) -> Option<Symbol> + 'a>>,
+ pub const_infer_name_resolver: Option<Box<dyn Fn(ty::ConstVid<'tcx>) -> Option<Symbol> + 'a>>,
+}
+
+impl<'a, 'tcx> Deref for FmtPrinter<'a, 'tcx> {
+ type Target = FmtPrinterData<'a, 'tcx>;
+ fn deref(&self) -> &Self::Target {
+ &self.0
+ }
+}
+
+impl DerefMut for FmtPrinter<'_, '_> {
+ fn deref_mut(&mut self) -> &mut Self::Target {
+ &mut self.0
+ }
+}
+
+impl<'a, 'tcx> FmtPrinter<'a, 'tcx> {
+ pub fn new(tcx: TyCtxt<'tcx>, ns: Namespace) -> Self {
+ FmtPrinter(Box::new(FmtPrinterData {
+ tcx,
+ // Estimated reasonable capacity to allocate upfront based on a few
+ // benchmarks.
+ fmt: String::with_capacity(64),
+ empty_path: false,
+ in_value: ns == Namespace::ValueNS,
+ print_alloc_ids: false,
+ used_region_names: Default::default(),
+ region_index: 0,
+ binder_depth: 0,
+ printed_type_count: 0,
+ region_highlight_mode: RegionHighlightMode::new(tcx),
+ ty_infer_name_resolver: None,
+ const_infer_name_resolver: None,
+ }))
+ }
+
+ pub fn into_buffer(self) -> String {
+ self.0.fmt
+ }
+}
+
+// HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
+// (but also some things just print a `DefId` generally so maybe we need this?)
+fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
+ match tcx.def_key(def_id).disambiguated_data.data {
+ DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
+ Namespace::TypeNS
+ }
+
+ DefPathData::ValueNs(..)
+ | DefPathData::AnonConst
+ | DefPathData::ClosureExpr
+ | DefPathData::Ctor => Namespace::ValueNS,
+
+ DefPathData::MacroNs(..) => Namespace::MacroNS,
+
+ _ => Namespace::TypeNS,
+ }
+}
+
+impl<'t> TyCtxt<'t> {
+ /// Returns a string identifying this `DefId`. This string is
+ /// suitable for user output.
+ pub fn def_path_str(self, def_id: DefId) -> String {
+ self.def_path_str_with_substs(def_id, &[])
+ }
+
+ pub fn def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String {
+ let ns = guess_def_namespace(self, def_id);
+ debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
+ FmtPrinter::new(self, ns).print_def_path(def_id, substs).unwrap().into_buffer()
+ }
+}
+
+impl fmt::Write for FmtPrinter<'_, '_> {
+ fn write_str(&mut self, s: &str) -> fmt::Result {
+ self.fmt.push_str(s);
+ Ok(())
+ }
+}
+
+impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
+ type Error = fmt::Error;
+
+ type Path = Self;
+ type Region = Self;
+ type Type = Self;
+ type DynExistential = Self;
+ type Const = Self;
+
+ fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
+ self.tcx
+ }
+
+ fn print_def_path(
+ mut self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ define_scoped_cx!(self);
+
+ if substs.is_empty() {
+ match self.try_print_trimmed_def_path(def_id)? {
+ (cx, true) => return Ok(cx),
+ (cx, false) => self = cx,
+ }
+
+ match self.try_print_visible_def_path(def_id)? {
+ (cx, true) => return Ok(cx),
+ (cx, false) => self = cx,
+ }
+ }
+
+ let key = self.tcx.def_key(def_id);
+ if let DefPathData::Impl = key.disambiguated_data.data {
+ // Always use types for non-local impls, where types are always
+ // available, and filename/line-number is mostly uninteresting.
+ let use_types = !def_id.is_local() || {
+ // Otherwise, use filename/line-number if forced.
+ let force_no_types = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
+ !force_no_types
+ };
+
+ if !use_types {
+ // If no type info is available, fall back to
+ // pretty printing some span information. This should
+ // only occur very early in the compiler pipeline.
+ let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
+ let span = self.tcx.def_span(def_id);
+
+ self = self.print_def_path(parent_def_id, &[])?;
+
+ // HACK(eddyb) copy of `path_append` to avoid
+ // constructing a `DisambiguatedDefPathData`.
+ if !self.empty_path {
+ write!(self, "::")?;
+ }
+ write!(
+ self,
+ "<impl at {}>",
+ // 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.empty_path = false;
+
+ return Ok(self);
+ }
+ }
+
+ self.default_print_def_path(def_id, substs)
+ }
+
+ fn print_region(self, region: ty::Region<'tcx>) -> Result<Self::Region, Self::Error> {
+ self.pretty_print_region(region)
+ }
+
+ fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
+ let type_length_limit = self.tcx.type_length_limit();
+ if type_length_limit.value_within_limit(self.printed_type_count) {
+ self.printed_type_count += 1;
+ self.pretty_print_type(ty)
+ } else {
+ write!(self, "...")?;
+ Ok(self)
+ }
+ }
+
+ fn print_dyn_existential(
+ self,
+ predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
+ ) -> Result<Self::DynExistential, Self::Error> {
+ self.pretty_print_dyn_existential(predicates)
+ }
+
+ fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
+ self.pretty_print_const(ct, false)
+ }
+
+ fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
+ self.empty_path = true;
+ if cnum == LOCAL_CRATE {
+ if self.tcx.sess.rust_2018() {
+ // We add the `crate::` keyword on Rust 2018, only when desired.
+ if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
+ write!(self, "{}", kw::Crate)?;
+ self.empty_path = false;
+ }
+ }
+ } else {
+ write!(self, "{}", self.tcx.crate_name(cnum))?;
+ self.empty_path = false;
+ }
+ Ok(self)
+ }
+
+ fn path_qualified(
+ mut self,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ self = self.pretty_path_qualified(self_ty, trait_ref)?;
+ self.empty_path = false;
+ Ok(self)
+ }
+
+ fn path_append_impl(
+ mut self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ _disambiguated_data: &DisambiguatedDefPathData,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ self = self.pretty_path_append_impl(
+ |mut cx| {
+ cx = print_prefix(cx)?;
+ if !cx.empty_path {
+ write!(cx, "::")?;
+ }
+
+ Ok(cx)
+ },
+ self_ty,
+ trait_ref,
+ )?;
+ self.empty_path = false;
+ Ok(self)
+ }
+
+ fn path_append(
+ mut self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ disambiguated_data: &DisambiguatedDefPathData,
+ ) -> Result<Self::Path, Self::Error> {
+ self = print_prefix(self)?;
+
+ // Skip `::{{extern}}` blocks and `::{{constructor}}` on tuple/unit structs.
+ if let DefPathData::ForeignMod | DefPathData::Ctor = disambiguated_data.data {
+ return Ok(self);
+ }
+
+ let name = disambiguated_data.data.name();
+ if !self.empty_path {
+ write!(self, "::")?;
+ }
+
+ if let DefPathDataName::Named(name) = name {
+ if Ident::with_dummy_span(name).is_raw_guess() {
+ write!(self, "r#")?;
+ }
+ }
+
+ let verbose = self.tcx.sess.verbose();
+ disambiguated_data.fmt_maybe_verbose(&mut self, verbose)?;
+
+ self.empty_path = false;
+
+ Ok(self)
+ }
+
+ fn path_generic_args(
+ mut self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ args: &[GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ self = print_prefix(self)?;
+
+ // Don't print `'_` if there's no unerased regions.
+ let print_regions = self.tcx.sess.verbose()
+ || args.iter().any(|arg| match arg.unpack() {
+ GenericArgKind::Lifetime(r) => !r.is_erased(),
+ _ => false,
+ });
+ let args = args.iter().cloned().filter(|arg| match arg.unpack() {
+ GenericArgKind::Lifetime(_) => print_regions,
+ _ => true,
+ });
+
+ if args.clone().next().is_some() {
+ if self.in_value {
+ write!(self, "::")?;
+ }
+ self.generic_delimiters(|cx| cx.comma_sep(args))
+ } else {
+ Ok(self)
+ }
+ }
+}
+
+impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
+ fn ty_infer_name(&self, id: ty::TyVid) -> Option<Symbol> {
+ self.0.ty_infer_name_resolver.as_ref().and_then(|func| func(id))
+ }
+
+ fn const_infer_name(&self, id: ty::ConstVid<'tcx>) -> Option<Symbol> {
+ self.0.const_infer_name_resolver.as_ref().and_then(|func| func(id))
+ }
+
+ fn print_value_path(
+ mut self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ let was_in_value = std::mem::replace(&mut self.in_value, true);
+ self = self.print_def_path(def_id, substs)?;
+ self.in_value = was_in_value;
+
+ Ok(self)
+ }
+
+ fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+ {
+ self.pretty_in_binder(value)
+ }
+
+ fn wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, Self::Error>>(
+ self,
+ value: &ty::Binder<'tcx, T>,
+ f: C,
+ ) -> Result<Self, Self::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+ {
+ self.pretty_wrap_binder(value, f)
+ }
+
+ fn typed_value(
+ mut self,
+ f: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ t: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ conversion: &str,
+ ) -> Result<Self::Const, Self::Error> {
+ self.write_str("{")?;
+ self = f(self)?;
+ self.write_str(conversion)?;
+ let was_in_value = std::mem::replace(&mut self.in_value, false);
+ self = t(self)?;
+ self.in_value = was_in_value;
+ self.write_str("}")?;
+ Ok(self)
+ }
+
+ fn generic_delimiters(
+ mut self,
+ f: impl FnOnce(Self) -> Result<Self, Self::Error>,
+ ) -> Result<Self, Self::Error> {
+ write!(self, "<")?;
+
+ let was_in_value = std::mem::replace(&mut self.in_value, false);
+ let mut inner = f(self)?;
+ inner.in_value = was_in_value;
+
+ write!(inner, ">")?;
+ Ok(inner)
+ }
+
+ fn should_print_region(&self, region: ty::Region<'tcx>) -> bool {
+ let highlight = self.region_highlight_mode;
+ if highlight.region_highlighted(region).is_some() {
+ return true;
+ }
+
+ if self.tcx.sess.verbose() {
+ return true;
+ }
+
+ let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
+
+ match *region {
+ ty::ReEarlyBound(ref data) => {
+ data.name != kw::Empty && data.name != kw::UnderscoreLifetime
+ }
+
+ ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
+ | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
+ | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
+ if let ty::BrNamed(_, name) = br {
+ if name != kw::Empty && name != kw::UnderscoreLifetime {
+ return true;
+ }
+ }
+
+ if let Some((region, _)) = highlight.highlight_bound_region {
+ if br == region {
+ return true;
+ }
+ }
+
+ false
+ }
+
+ ty::ReVar(_) if identify_regions => true,
+
+ ty::ReVar(_) | ty::ReErased => false,
+
+ ty::ReStatic | ty::ReEmpty(_) => true,
+ }
+ }
+
+ fn pretty_print_const_pointer<Prov: Provenance>(
+ self,
+ p: Pointer<Prov>,
+ ty: Ty<'tcx>,
+ print_ty: bool,
+ ) -> Result<Self::Const, Self::Error> {
+ let print = |mut this: Self| {
+ define_scoped_cx!(this);
+ if this.print_alloc_ids {
+ p!(write("{:?}", p));
+ } else {
+ p!("&_");
+ }
+ Ok(this)
+ };
+ if print_ty {
+ self.typed_value(print, |this| this.print_type(ty), ": ")
+ } else {
+ print(self)
+ }
+ }
+}
+
+// HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
+impl<'tcx> FmtPrinter<'_, 'tcx> {
+ pub fn pretty_print_region(mut self, region: ty::Region<'tcx>) -> Result<Self, fmt::Error> {
+ define_scoped_cx!(self);
+
+ // Watch out for region highlights.
+ let highlight = self.region_highlight_mode;
+ if let Some(n) = highlight.region_highlighted(region) {
+ p!(write("'{}", n));
+ return Ok(self);
+ }
+
+ if self.tcx.sess.verbose() {
+ p!(write("{:?}", region));
+ return Ok(self);
+ }
+
+ let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
+
+ // 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
+ // `explain_region()` or `note_and_explain_region()`.
+ match *region {
+ ty::ReEarlyBound(ref data) => {
+ if data.name != kw::Empty {
+ p!(write("{}", data.name));
+ return Ok(self);
+ }
+ }
+ ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
+ | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
+ | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
+ if let ty::BrNamed(_, name) = br {
+ if name != kw::Empty && name != kw::UnderscoreLifetime {
+ p!(write("{}", name));
+ return Ok(self);
+ }
+ }
+
+ if let Some((region, counter)) = highlight.highlight_bound_region {
+ if br == region {
+ p!(write("'{}", counter));
+ return Ok(self);
+ }
+ }
+ }
+ ty::ReVar(region_vid) if identify_regions => {
+ p!(write("{:?}", region_vid));
+ return Ok(self);
+ }
+ ty::ReVar(_) => {}
+ ty::ReErased => {}
+ ty::ReStatic => {
+ p!("'static");
+ return Ok(self);
+ }
+ ty::ReEmpty(ty::UniverseIndex::ROOT) => {
+ p!("'<empty>");
+ return Ok(self);
+ }
+ ty::ReEmpty(ui) => {
+ p!(write("'<empty:{:?}>", ui));
+ return Ok(self);
+ }
+ }
+
+ p!("'_");
+
+ Ok(self)
+ }
+}
+
+/// Folds through bound vars and placeholders, naming them
+struct RegionFolder<'a, 'tcx> {
+ tcx: TyCtxt<'tcx>,
+ current_index: ty::DebruijnIndex,
+ region_map: BTreeMap<ty::BoundRegion, ty::Region<'tcx>>,
+ name: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a),
+}
+
+impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> {
+ fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+ self.tcx
+ }
+
+ fn fold_binder<T: TypeFoldable<'tcx>>(
+ &mut self,
+ t: ty::Binder<'tcx, T>,
+ ) -> ty::Binder<'tcx, T> {
+ self.current_index.shift_in(1);
+ let t = t.super_fold_with(self);
+ self.current_index.shift_out(1);
+ t
+ }
+
+ fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
+ match *t.kind() {
+ _ if t.has_vars_bound_at_or_above(self.current_index) || t.has_placeholders() => {
+ return t.super_fold_with(self);
+ }
+ _ => {}
+ }
+ t
+ }
+
+ fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
+ let name = &mut self.name;
+ let region = match *r {
+ ty::ReLateBound(_, br) => *self.region_map.entry(br).or_insert_with(|| name(br)),
+ ty::RePlaceholder(ty::PlaceholderRegion { name: kind, .. }) => {
+ // If this is an anonymous placeholder, don't rename. Otherwise, in some
+ // async fns, we get a `for<'r> Send` bound
+ match kind {
+ ty::BrAnon(_) | ty::BrEnv => r,
+ _ => {
+ // Index doesn't matter, since this is just for naming and these never get bound
+ let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind };
+ *self.region_map.entry(br).or_insert_with(|| name(br))
+ }
+ }
+ }
+ _ => return r,
+ };
+ if let ty::ReLateBound(debruijn1, br) = *region {
+ assert_eq!(debruijn1, ty::INNERMOST);
+ self.tcx.mk_region(ty::ReLateBound(self.current_index, br))
+ } else {
+ region
+ }
+ }
+}
+
+// HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
+// `region_index` and `used_region_names`.
+impl<'tcx> FmtPrinter<'_, 'tcx> {
+ pub fn name_all_regions<T>(
+ mut self,
+ value: &ty::Binder<'tcx, T>,
+ ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+ {
+ fn name_by_region_index(index: usize) -> Symbol {
+ match index {
+ 0 => Symbol::intern("'r"),
+ 1 => Symbol::intern("'s"),
+ i => Symbol::intern(&format!("'t{}", i - 2)),
+ }
+ }
+
+ // Replace any anonymous late-bound regions with named
+ // variants, using new unique identifiers, so that we can
+ // clearly differentiate between named and unnamed regions in
+ // the output. We'll probably want to tweak this over time to
+ // decide just how much information to give.
+ if self.binder_depth == 0 {
+ self.prepare_late_bound_region_info(value);
+ }
+
+ let mut empty = true;
+ let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
+ let w = if empty {
+ empty = false;
+ start
+ } else {
+ cont
+ };
+ let _ = write!(cx, "{}", w);
+ };
+ let do_continue = |cx: &mut Self, cont: Symbol| {
+ let _ = write!(cx, "{}", cont);
+ };
+
+ define_scoped_cx!(self);
+
+ let mut region_index = self.region_index;
+ let mut next_name = |this: &Self| loop {
+ let name = name_by_region_index(region_index);
+ region_index += 1;
+ if !this.used_region_names.contains(&name) {
+ break name;
+ }
+ };
+
+ // If we want to print verbosely, then print *all* binders, even if they
+ // aren't named. Eventually, we might just want this as the default, but
+ // this is not *quite* right and changes the ordering of some output
+ // anyways.
+ let (new_value, map) = if self.tcx().sess.verbose() {
+ let regions: Vec<_> = value
+ .bound_vars()
+ .into_iter()
+ .map(|var| {
+ let ty::BoundVariableKind::Region(var) = var else {
+ // This doesn't really matter because it doesn't get used,
+ // it's just an empty value
+ return ty::BrAnon(0);
+ };
+ match var {
+ ty::BrAnon(_) | ty::BrEnv => {
+ start_or_continue(&mut self, "for<", ", ");
+ let name = next_name(&self);
+ do_continue(&mut self, name);
+ ty::BrNamed(CRATE_DEF_ID.to_def_id(), name)
+ }
+ ty::BrNamed(def_id, kw::UnderscoreLifetime) => {
+ start_or_continue(&mut self, "for<", ", ");
+ let name = next_name(&self);
+ do_continue(&mut self, name);
+ ty::BrNamed(def_id, name)
+ }
+ ty::BrNamed(def_id, name) => {
+ start_or_continue(&mut self, "for<", ", ");
+ do_continue(&mut self, name);
+ ty::BrNamed(def_id, name)
+ }
+ }
+ })
+ .collect();
+ start_or_continue(&mut self, "", "> ");
+
+ self.tcx.replace_late_bound_regions(value.clone(), |br| {
+ let kind = regions[br.var.as_usize()];
+ self.tcx.mk_region(ty::ReLateBound(
+ ty::INNERMOST,
+ ty::BoundRegion { var: br.var, kind },
+ ))
+ })
+ } else {
+ let tcx = self.tcx;
+ let mut name = |br: ty::BoundRegion| {
+ start_or_continue(&mut self, "for<", ", ");
+ let kind = match br.kind {
+ ty::BrAnon(_) | ty::BrEnv => {
+ let name = next_name(&self);
+ do_continue(&mut self, name);
+ ty::BrNamed(CRATE_DEF_ID.to_def_id(), name)
+ }
+ ty::BrNamed(def_id, kw::UnderscoreLifetime) => {
+ let name = next_name(&self);
+ do_continue(&mut self, name);
+ ty::BrNamed(def_id, name)
+ }
+ ty::BrNamed(_, name) => {
+ do_continue(&mut self, name);
+ br.kind
+ }
+ };
+ tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { var: br.var, kind }))
+ };
+ let mut folder = RegionFolder {
+ tcx,
+ current_index: ty::INNERMOST,
+ name: &mut name,
+ region_map: BTreeMap::new(),
+ };
+ let new_value = value.clone().skip_binder().fold_with(&mut folder);
+ let region_map = folder.region_map;
+ start_or_continue(&mut self, "", "> ");
+ (new_value, region_map)
+ };
+
+ self.binder_depth += 1;
+ self.region_index = region_index;
+ Ok((self, new_value, map))
+ }
+
+ pub fn pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+ {
+ let old_region_index = self.region_index;
+ let (new, new_value, _) = self.name_all_regions(value)?;
+ let mut inner = new_value.print(new)?;
+ inner.region_index = old_region_index;
+ inner.binder_depth -= 1;
+ Ok(inner)
+ }
+
+ pub fn pretty_wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
+ self,
+ value: &ty::Binder<'tcx, T>,
+ f: C,
+ ) -> Result<Self, fmt::Error>
+ where
+ T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+ {
+ let old_region_index = self.region_index;
+ let (new, new_value, _) = self.name_all_regions(value)?;
+ let mut inner = f(&new_value, new)?;
+ inner.region_index = old_region_index;
+ inner.binder_depth -= 1;
+ Ok(inner)
+ }
+
+ fn prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
+ where
+ T: TypeVisitable<'tcx>,
+ {
+ struct LateBoundRegionNameCollector<'a, 'tcx> {
+ used_region_names: &'a mut FxHashSet<Symbol>,
+ type_collector: SsoHashSet<Ty<'tcx>>,
+ }
+
+ impl<'tcx> ty::visit::TypeVisitor<'tcx> for LateBoundRegionNameCollector<'_, 'tcx> {
+ type BreakTy = ();
+
+ fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
+ trace!("address: {:p}", r.0.0);
+ if let ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrNamed(_, name), .. }) = *r {
+ self.used_region_names.insert(name);
+ } else if let ty::RePlaceholder(ty::PlaceholderRegion {
+ name: ty::BrNamed(_, name),
+ ..
+ }) = *r
+ {
+ self.used_region_names.insert(name);
+ }
+ r.super_visit_with(self)
+ }
+
+ // We collect types in order to prevent really large types from compiling for
+ // a really long time. See issue #83150 for why this is necessary.
+ fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
+ let not_previously_inserted = self.type_collector.insert(ty);
+ if not_previously_inserted {
+ ty.super_visit_with(self)
+ } else {
+ ControlFlow::CONTINUE
+ }
+ }
+ }
+
+ self.used_region_names.clear();
+ let mut collector = LateBoundRegionNameCollector {
+ used_region_names: &mut self.used_region_names,
+ type_collector: SsoHashSet::new(),
+ };
+ value.visit_with(&mut collector);
+ self.region_index = 0;
+ }
+}
+
+impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
+where
+ T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
+{
+ type Output = P;
+ type Error = P::Error;
+
+ fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
+ cx.in_binder(self)
+ }
+}
+
+impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
+where
+ T: Print<'tcx, P, Output = P, Error = P::Error>,
+ U: Print<'tcx, P, Output = P, Error = P::Error>,
+{
+ type Output = P;
+ type Error = P::Error;
+ fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
+ define_scoped_cx!(cx);
+ p!(print(self.0), ": ", print(self.1));
+ Ok(cx)
+ }
+}
+
+macro_rules! forward_display_to_print {
+ ($($ty:ty),+) => {
+ // Some of the $ty arguments may not actually use 'tcx
+ $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ ty::tls::with(|tcx| {
+ let cx = tcx.lift(*self)
+ .expect("could not lift for printing")
+ .print(FmtPrinter::new(tcx, Namespace::TypeNS))?;
+ f.write_str(&cx.into_buffer())?;
+ Ok(())
+ })
+ }
+ })+
+ };
+}
+
+macro_rules! define_print_and_forward_display {
+ (($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
+ $(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
+ type Output = P;
+ type Error = fmt::Error;
+ fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
+ #[allow(unused_mut)]
+ let mut $cx = $cx;
+ define_scoped_cx!($cx);
+ let _: () = $print;
+ #[allow(unreachable_code)]
+ Ok($cx)
+ }
+ })+
+
+ forward_display_to_print!($($ty),+);
+ };
+}
+
+/// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
+/// the trait path. That is, it will print `Trait<U>` instead of
+/// `<T as Trait<U>>`.
+#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
+pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
+
+impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Display::fmt(self, f)
+ }
+}
+
+/// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
+/// the trait name. That is, it will print `Trait` instead of
+/// `<T as Trait<U>>`.
+#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
+pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
+
+impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Display::fmt(self, f)
+ }
+}
+
+impl<'tcx> ty::TraitRef<'tcx> {
+ pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
+ TraitRefPrintOnlyTraitPath(self)
+ }
+
+ pub fn print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx> {
+ TraitRefPrintOnlyTraitName(self)
+ }
+}
+
+impl<'tcx> ty::Binder<'tcx, ty::TraitRef<'tcx>> {
+ pub fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
+ self.map_bound(|tr| tr.print_only_trait_path())
+ }
+}
+
+#[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
+pub struct TraitPredPrintModifiersAndPath<'tcx>(ty::TraitPredicate<'tcx>);
+
+impl<'tcx> fmt::Debug for TraitPredPrintModifiersAndPath<'tcx> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Display::fmt(self, f)
+ }
+}
+
+impl<'tcx> ty::TraitPredicate<'tcx> {
+ pub fn print_modifiers_and_trait_path(self) -> TraitPredPrintModifiersAndPath<'tcx> {
+ TraitPredPrintModifiersAndPath(self)
+ }
+}
+
+impl<'tcx> ty::PolyTraitPredicate<'tcx> {
+ pub fn print_modifiers_and_trait_path(
+ self,
+ ) -> ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>> {
+ self.map_bound(TraitPredPrintModifiersAndPath)
+ }
+}
+
+forward_display_to_print! {
+ ty::Region<'tcx>,
+ Ty<'tcx>,
+ &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
+ ty::Const<'tcx>,
+
+ // HACK(eddyb) these are exhaustive instead of generic,
+ // because `for<'tcx>` isn't possible yet.
+ ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>,
+ ty::Binder<'tcx, ty::TraitRef<'tcx>>,
+ ty::Binder<'tcx, ty::ExistentialTraitRef<'tcx>>,
+ ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>,
+ ty::Binder<'tcx, TraitRefPrintOnlyTraitName<'tcx>>,
+ ty::Binder<'tcx, ty::FnSig<'tcx>>,
+ ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,
+ ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>>,
+ ty::Binder<'tcx, ty::SubtypePredicate<'tcx>>,
+ ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
+ ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
+ ty::Binder<'tcx, ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
+
+ ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
+ ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
+}
+
+define_print_and_forward_display! {
+ (self, cx):
+
+ &'tcx ty::List<Ty<'tcx>> {
+ p!("{{", comma_sep(self.iter()), "}}")
+ }
+
+ ty::TypeAndMut<'tcx> {
+ p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
+ }
+
+ ty::ExistentialTraitRef<'tcx> {
+ // Use a type that can't appear in defaults of type parameters.
+ let dummy_self = cx.tcx().mk_ty_infer(ty::FreshTy(0));
+ let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
+ p!(print(trait_ref.print_only_trait_path()))
+ }
+
+ ty::ExistentialProjection<'tcx> {
+ let name = cx.tcx().associated_item(self.item_def_id).name;
+ p!(write("{} = ", name), print(self.term))
+ }
+
+ ty::ExistentialPredicate<'tcx> {
+ match *self {
+ ty::ExistentialPredicate::Trait(x) => p!(print(x)),
+ ty::ExistentialPredicate::Projection(x) => p!(print(x)),
+ ty::ExistentialPredicate::AutoTrait(def_id) => {
+ p!(print_def_path(def_id, &[]));
+ }
+ }
+ }
+
+ ty::FnSig<'tcx> {
+ p!(write("{}", self.unsafety.prefix_str()));
+
+ if self.abi != Abi::Rust {
+ p!(write("extern {} ", self.abi));
+ }
+
+ p!("fn", pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
+ }
+
+ ty::TraitRef<'tcx> {
+ p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
+ }
+
+ TraitRefPrintOnlyTraitPath<'tcx> {
+ p!(print_def_path(self.0.def_id, self.0.substs));
+ }
+
+ TraitRefPrintOnlyTraitName<'tcx> {
+ p!(print_def_path(self.0.def_id, &[]));
+ }
+
+ TraitPredPrintModifiersAndPath<'tcx> {
+ if let ty::BoundConstness::ConstIfConst = self.0.constness {
+ p!("~const ")
+ }
+
+ if let ty::ImplPolarity::Negative = self.0.polarity {
+ p!("!")
+ }
+
+ p!(print(self.0.trait_ref.print_only_trait_path()));
+ }
+
+ ty::ParamTy {
+ p!(write("{}", self.name))
+ }
+
+ ty::ParamConst {
+ p!(write("{}", self.name))
+ }
+
+ ty::SubtypePredicate<'tcx> {
+ p!(print(self.a), " <: ", print(self.b))
+ }
+
+ ty::CoercePredicate<'tcx> {
+ p!(print(self.a), " -> ", print(self.b))
+ }
+
+ ty::TraitPredicate<'tcx> {
+ p!(print(self.trait_ref.self_ty()), ": ");
+ if let ty::BoundConstness::ConstIfConst = self.constness && cx.tcx().features().const_trait_impl {
+ p!("~const ");
+ }
+ p!(print(self.trait_ref.print_only_trait_path()))
+ }
+
+ ty::ProjectionPredicate<'tcx> {
+ p!(print(self.projection_ty), " == ", print(self.term))
+ }
+
+ ty::Term<'tcx> {
+ match self {
+ ty::Term::Ty(ty) => p!(print(ty)),
+ ty::Term::Const(c) => p!(print(c)),
+ }
+ }
+
+ ty::ProjectionTy<'tcx> {
+ p!(print_def_path(self.item_def_id, self.substs));
+ }
+
+ ty::ClosureKind {
+ match *self {
+ ty::ClosureKind::Fn => p!("Fn"),
+ ty::ClosureKind::FnMut => p!("FnMut"),
+ ty::ClosureKind::FnOnce => p!("FnOnce"),
+ }
+ }
+
+ ty::Predicate<'tcx> {
+ let binder = self.kind();
+ p!(print(binder))
+ }
+
+ ty::PredicateKind<'tcx> {
+ match *self {
+ ty::PredicateKind::Trait(ref data) => {
+ p!(print(data))
+ }
+ ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
+ ty::PredicateKind::Coerce(predicate) => p!(print(predicate)),
+ ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)),
+ ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)),
+ ty::PredicateKind::Projection(predicate) => p!(print(predicate)),
+ ty::PredicateKind::WellFormed(arg) => p!(print(arg), " well-formed"),
+ ty::PredicateKind::ObjectSafe(trait_def_id) => {
+ p!("the trait `", print_def_path(trait_def_id, &[]), "` is object-safe")
+ }
+ ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => {
+ p!("the closure `",
+ print_value_path(closure_def_id, &[]),
+ write("` implements the trait `{}`", kind))
+ }
+ ty::PredicateKind::ConstEvaluatable(uv) => {
+ p!("the constant `", print_value_path(uv.def.did, uv.substs), "` can be evaluated")
+ }
+ ty::PredicateKind::ConstEquate(c1, c2) => {
+ p!("the constant `", print(c1), "` equals `", print(c2), "`")
+ }
+ ty::PredicateKind::TypeWellFormedFromEnv(ty) => {
+ p!("the type `", print(ty), "` is found in the environment")
+ }
+ }
+ }
+
+ GenericArg<'tcx> {
+ match self.unpack() {
+ GenericArgKind::Lifetime(lt) => p!(print(lt)),
+ GenericArgKind::Type(ty) => p!(print(ty)),
+ GenericArgKind::Const(ct) => p!(print(ct)),
+ }
+ }
+}
+
+fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId)) {
+ // Iterate all local crate items no matter where they are defined.
+ let hir = tcx.hir();
+ for id in hir.items() {
+ if matches!(tcx.def_kind(id.def_id), DefKind::Use) {
+ continue;
+ }
+
+ let item = hir.item(id);
+ if item.ident.name == kw::Empty {
+ continue;
+ }
+
+ let def_id = item.def_id.to_def_id();
+ let ns = tcx.def_kind(def_id).ns().unwrap_or(Namespace::TypeNS);
+ collect_fn(&item.ident, ns, def_id);
+ }
+
+ // Now take care of extern crate items.
+ let queue = &mut Vec::new();
+ let mut seen_defs: DefIdSet = Default::default();
+
+ for &cnum in tcx.crates(()).iter() {
+ let def_id = cnum.as_def_id();
+
+ // Ignore crates that are not direct dependencies.
+ match tcx.extern_crate(def_id) {
+ None => continue,
+ Some(extern_crate) => {
+ if !extern_crate.is_direct() {
+ continue;
+ }
+ }
+ }
+
+ queue.push(def_id);
+ }
+
+ // Iterate external crate defs but be mindful about visibility
+ while let Some(def) = queue.pop() {
+ for child in tcx.module_children(def).iter() {
+ if !child.vis.is_public() {
+ continue;
+ }
+
+ match child.res {
+ def::Res::Def(DefKind::AssocTy, _) => {}
+ def::Res::Def(DefKind::TyAlias, _) => {}
+ def::Res::Def(defkind, def_id) => {
+ if let Some(ns) = defkind.ns() {
+ collect_fn(&child.ident, ns, def_id);
+ }
+
+ if matches!(defkind, DefKind::Mod | DefKind::Enum | DefKind::Trait)
+ && seen_defs.insert(def_id)
+ {
+ queue.push(def_id);
+ }
+ }
+ _ => {}
+ }
+ }
+ }
+}
+
+/// The purpose of this function is to collect public symbols names that are unique across all
+/// crates in the build. Later, when printing about types we can use those names instead of the
+/// full exported path to them.
+///
+/// So essentially, if a symbol name can only be imported from one place for a type, and as
+/// long as it was not glob-imported anywhere in the current crate, we can trim its printed
+/// path and print only the name.
+///
+/// This has wide implications on error messages with types, for example, shortening
+/// `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.
+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 {
+ // 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");
+ }
+
+ let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
+ &mut FxHashMap::default();
+
+ for symbol_set in tcx.resolutions(()).glob_map.values() {
+ for symbol in symbol_set {
+ unique_symbols_rev.insert((Namespace::TypeNS, *symbol), None);
+ unique_symbols_rev.insert((Namespace::ValueNS, *symbol), None);
+ unique_symbols_rev.insert((Namespace::MacroNS, *symbol), None);
+ }
+ }
+
+ for_each_def(tcx, |ident, ns, def_id| {
+ use std::collections::hash_map::Entry::{Occupied, Vacant};
+
+ match unique_symbols_rev.entry((ns, ident.name)) {
+ Occupied(mut v) => match v.get() {
+ None => {}
+ Some(existing) => {
+ if *existing != def_id {
+ v.insert(None);
+ }
+ }
+ },
+ Vacant(v) => {
+ v.insert(Some(def_id));
+ }
+ }
+ });
+
+ for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
+ use std::collections::hash_map::Entry::{Occupied, Vacant};
+
+ if let Some(def_id) = opt_def_id {
+ match map.entry(def_id) {
+ Occupied(mut v) => {
+ // A single DefId can be known under multiple names (e.g.,
+ // with a `pub use ... as ...;`). We need to ensure that the
+ // name placed in this map is chosen deterministically, so
+ // if we find multiple names (`symbol`) resolving to the
+ // same `def_id`, we prefer the lexicographically smallest
+ // name.
+ //
+ // Any stable ordering would be fine here though.
+ if *v.get() != symbol {
+ if v.get().as_str() > symbol.as_str() {
+ v.insert(symbol);
+ }
+ }
+ }
+ Vacant(v) => {
+ v.insert(symbol);
+ }
+ }
+ }
+ }
+
+ map
+}
+
+pub fn provide(providers: &mut ty::query::Providers) {
+ *providers = ty::query::Providers { trimmed_def_paths, ..*providers };
+}
+
+#[derive(Default)]
+pub struct OpaqueFnEntry<'tcx> {
+ // The trait ref is already stored as a key, so just track if we have it as a real predicate
+ has_fn_once: bool,
+ fn_mut_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
+ fn_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
+ return_ty: Option<ty::Binder<'tcx, Term<'tcx>>>,
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 07:26:56 +0000