1 use crate::mir::interpret::{AllocRange, ConstValue, GlobalAlloc, Pointer, Provenance, Scalar};
2 use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
3 use crate::ty::{self, ConstInt, DefIdTree, ParamConst, ScalarInt, Ty, TyCtxt, TypeFoldable};
4 use rustc_apfloat::ieee::{Double, Single};
5 use rustc_data_structures::fx::FxHashMap;
6 use rustc_data_structures::sso::SsoHashSet;
8 use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
9 use rustc_hir::def_id::{DefId, DefIdSet, CRATE_DEF_INDEX, LOCAL_CRATE};
10 use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData};
11 use rustc_hir::ItemKind;
12 use rustc_session::config::TrimmedDefPaths;
13 use rustc_session::cstore::{ExternCrate, ExternCrateSource};
14 use rustc_span::symbol::{kw, Ident, Symbol};
15 use rustc_target::abi::Size;
16 use rustc_target::spec::abi::Abi;
20 use std::collections::BTreeMap;
21 use std::convert::TryFrom;
22 use std::fmt::{self, Write as _};
24 use std::ops::{ControlFlow, Deref, DerefMut};
26 // `pretty` is a separate module only for organization.
31 write!(scoped_cx!(), $lit)?
33 (@write($($data:expr),+)) => {
34 write!(scoped_cx!(), $($data),+)?
36 (@print($x:expr)) => {
37 scoped_cx!() = $x.print(scoped_cx!())?
39 (@$method:ident($($arg:expr),*)) => {
40 scoped_cx!() = scoped_cx!().$method($($arg),*)?
42 ($($elem:tt $(($($args:tt)*))?),+) => {{
43 $(p!(@ $elem $(($($args)*))?);)+
46 macro_rules! define_scoped_cx {
48 #[allow(unused_macros)]
49 macro_rules! scoped_cx {
58 static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) };
59 static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) };
60 static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
61 static NO_QUERIES: Cell<bool> = const { Cell::new(false) };
62 static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) };
65 /// Avoids running any queries during any prints that occur
66 /// during the closure. This may alter the appearance of some
67 /// types (e.g. forcing verbose printing for opaque types).
68 /// This method is used during some queries (e.g. `explicit_item_bounds`
69 /// for opaque types), to ensure that any debug printing that
70 /// occurs during the query computation does not end up recursively
71 /// calling the same query.
72 pub fn with_no_queries<F: FnOnce() -> R, R>(f: F) -> R {
73 NO_QUERIES.with(|no_queries| {
74 let old = no_queries.replace(true);
81 /// Force us to name impls with just the filename/line number. We
82 /// normally try to use types. But at some points, notably while printing
83 /// cycle errors, this can result in extra or suboptimal error output,
84 /// so this variable disables that check.
85 pub fn with_forced_impl_filename_line<F: FnOnce() -> R, R>(f: F) -> R {
86 FORCE_IMPL_FILENAME_LINE.with(|force| {
87 let old = force.replace(true);
94 /// Adds the `crate::` prefix to paths where appropriate.
95 pub fn with_crate_prefix<F: FnOnce() -> R, R>(f: F) -> R {
96 SHOULD_PREFIX_WITH_CRATE.with(|flag| {
97 let old = flag.replace(true);
104 /// Prevent path trimming if it is turned on. Path trimming affects `Display` impl
105 /// of various rustc types, for example `std::vec::Vec` would be trimmed to `Vec`,
106 /// if no other `Vec` is found.
107 pub fn with_no_trimmed_paths<F: FnOnce() -> R, R>(f: F) -> R {
108 NO_TRIMMED_PATH.with(|flag| {
109 let old = flag.replace(true);
116 /// Prevent selection of visible paths. `Display` impl of DefId will prefer visible (public) reexports of types as paths.
117 pub fn with_no_visible_paths<F: FnOnce() -> R, R>(f: F) -> R {
118 NO_VISIBLE_PATH.with(|flag| {
119 let old = flag.replace(true);
126 /// The "region highlights" are used to control region printing during
127 /// specific error messages. When a "region highlight" is enabled, it
128 /// gives an alternate way to print specific regions. For now, we
129 /// always print those regions using a number, so something like "`'0`".
131 /// Regions not selected by the region highlight mode are presently
133 #[derive(Copy, Clone, Default)]
134 pub struct RegionHighlightMode {
135 /// If enabled, when we see the selected region, use "`'N`"
136 /// instead of the ordinary behavior.
137 highlight_regions: [Option<(ty::RegionKind, usize)>; 3],
139 /// If enabled, when printing a "free region" that originated from
140 /// the given `ty::BoundRegionKind`, print it as "`'1`". Free regions that would ordinarily
141 /// have names print as normal.
143 /// This is used when you have a signature like `fn foo(x: &u32,
144 /// y: &'a u32)` and we want to give a name to the region of the
146 highlight_bound_region: Option<(ty::BoundRegionKind, usize)>,
149 impl RegionHighlightMode {
150 /// If `region` and `number` are both `Some`, invokes
151 /// `highlighting_region`.
152 pub fn maybe_highlighting_region(
154 region: Option<ty::Region<'_>>,
155 number: Option<usize>,
157 if let Some(k) = region {
158 if let Some(n) = number {
159 self.highlighting_region(k, n);
164 /// Highlights the region inference variable `vid` as `'N`.
165 pub fn highlighting_region(&mut self, region: ty::Region<'_>, number: usize) {
166 let num_slots = self.highlight_regions.len();
167 let first_avail_slot =
168 self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
169 bug!("can only highlight {} placeholders at a time", num_slots,)
171 *first_avail_slot = Some((*region, number));
174 /// Convenience wrapper for `highlighting_region`.
175 pub fn highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize) {
176 self.highlighting_region(&ty::ReVar(vid), number)
179 /// Returns `Some(n)` with the number to use for the given region, if any.
180 fn region_highlighted(&self, region: ty::Region<'_>) -> Option<usize> {
181 self.highlight_regions.iter().find_map(|h| match h {
182 Some((r, n)) if r == region => Some(*n),
187 /// Highlight the given bound region.
188 /// We can only highlight one bound region at a time. See
189 /// the field `highlight_bound_region` for more detailed notes.
190 pub fn highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize) {
191 assert!(self.highlight_bound_region.is_none());
192 self.highlight_bound_region = Some((br, number));
196 /// Trait for printers that pretty-print using `fmt::Write` to the printer.
197 pub trait PrettyPrinter<'tcx>:
204 DynExistential = Self,
208 /// Like `print_def_path` but for value paths.
212 substs: &'tcx [GenericArg<'tcx>],
213 ) -> Result<Self::Path, Self::Error> {
214 self.print_def_path(def_id, substs)
217 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
219 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
221 value.as_ref().skip_binder().print(self)
224 fn wrap_binder<T, F: Fn(&T, Self) -> Result<Self, fmt::Error>>(
226 value: &ty::Binder<'tcx, T>,
228 ) -> Result<Self, Self::Error>
230 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
232 f(value.as_ref().skip_binder(), self)
235 /// Prints comma-separated elements.
236 fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
238 T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
240 if let Some(first) = elems.next() {
241 self = first.print(self)?;
243 self.write_str(", ")?;
244 self = elem.print(self)?;
250 /// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
253 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
254 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
256 ) -> Result<Self::Const, Self::Error> {
257 self.write_str("{")?;
259 self.write_str(conversion)?;
261 self.write_str("}")?;
265 /// Prints `<...>` around what `f` prints.
266 fn generic_delimiters(
268 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
269 ) -> Result<Self, Self::Error>;
271 /// Returns `true` if the region should be printed in
272 /// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
273 /// This is typically the case for all non-`'_` regions.
274 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool;
276 // Defaults (should not be overridden):
278 /// If possible, this returns a global path resolving to `def_id` that is visible
279 /// from at least one local module, and returns `true`. If the crate defining `def_id` is
280 /// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
281 fn try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
282 if NO_VISIBLE_PATH.with(|flag| flag.get()) {
283 return Ok((self, false));
286 let mut callers = Vec::new();
287 self.try_print_visible_def_path_recur(def_id, &mut callers)
290 /// Try to see if this path can be trimmed to a unique symbol name.
291 fn try_print_trimmed_def_path(
294 ) -> Result<(Self::Path, bool), Self::Error> {
295 if !self.tcx().sess.opts.debugging_opts.trim_diagnostic_paths
296 || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never)
297 || NO_TRIMMED_PATH.with(|flag| flag.get())
298 || SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get())
300 return Ok((self, false));
303 match self.tcx().trimmed_def_paths(()).get(&def_id) {
304 None => Ok((self, false)),
306 self.write_str(symbol.as_str())?;
312 /// Does the work of `try_print_visible_def_path`, building the
313 /// full definition path recursively before attempting to
314 /// post-process it into the valid and visible version that
315 /// accounts for re-exports.
317 /// This method should only be called by itself or
318 /// `try_print_visible_def_path`.
320 /// `callers` is a chain of visible_parent's leading to `def_id`,
321 /// to support cycle detection during recursion.
323 /// This method returns false if we can't print the visible path, so
324 /// `print_def_path` can fall back on the item's real definition path.
325 fn try_print_visible_def_path_recur(
328 callers: &mut Vec<DefId>,
329 ) -> Result<(Self, bool), Self::Error> {
330 define_scoped_cx!(self);
332 debug!("try_print_visible_def_path: def_id={:?}", def_id);
334 // If `def_id` is a direct or injected extern crate, return the
335 // path to the crate followed by the path to the item within the crate.
336 if def_id.index == CRATE_DEF_INDEX {
337 let cnum = def_id.krate;
339 if cnum == LOCAL_CRATE {
340 return Ok((self.path_crate(cnum)?, true));
343 // In local mode, when we encounter a crate other than
344 // LOCAL_CRATE, execution proceeds in one of two ways:
346 // 1. For a direct dependency, where user added an
347 // `extern crate` manually, we put the `extern
348 // crate` as the parent. So you wind up with
349 // something relative to the current crate.
350 // 2. For an extern inferred from a path or an indirect crate,
351 // where there is no explicit `extern crate`, we just prepend
353 match self.tcx().extern_crate(def_id) {
354 Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
355 (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
356 // NOTE(eddyb) the only reason `span` might be dummy,
357 // that we're aware of, is that it's the `std`/`core`
358 // `extern crate` injected by default.
359 // FIXME(eddyb) find something better to key this on,
360 // or avoid ending up with `ExternCrateSource::Extern`,
361 // for the injected `std`/`core`.
363 return Ok((self.path_crate(cnum)?, true));
366 // Disable `try_print_trimmed_def_path` behavior within
367 // the `print_def_path` call, to avoid infinite recursion
368 // in cases where the `extern crate foo` has non-trivial
369 // parents, e.g. it's nested in `impl foo::Trait for Bar`
370 // (see also issues #55779 and #87932).
371 self = with_no_visible_paths(|| self.print_def_path(def_id, &[]))?;
373 return Ok((self, true));
375 (ExternCrateSource::Path, LOCAL_CRATE) => {
376 return Ok((self.path_crate(cnum)?, true));
381 return Ok((self.path_crate(cnum)?, true));
386 if def_id.is_local() {
387 return Ok((self, false));
390 let visible_parent_map = self.tcx().visible_parent_map(());
392 let mut cur_def_key = self.tcx().def_key(def_id);
393 debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
395 // For a constructor, we want the name of its parent rather than <unnamed>.
396 if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
401 .expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
404 cur_def_key = self.tcx().def_key(parent);
407 let visible_parent = match visible_parent_map.get(&def_id).cloned() {
408 Some(parent) => parent,
409 None => return Ok((self, false)),
412 let actual_parent = self.tcx().parent(def_id);
414 "try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
415 visible_parent, actual_parent,
418 let mut data = cur_def_key.disambiguated_data.data;
420 "try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
421 data, visible_parent, actual_parent,
425 // In order to output a path that could actually be imported (valid and visible),
426 // we need to handle re-exports correctly.
428 // For example, take `std::os::unix::process::CommandExt`, this trait is actually
429 // defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
431 // `std::os::unix` rexports the contents of `std::sys::unix::ext`. `std::sys` is
432 // private so the "true" path to `CommandExt` isn't accessible.
434 // In this case, the `visible_parent_map` will look something like this:
436 // (child) -> (parent)
437 // `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
438 // `std::sys::unix::ext::process` -> `std::sys::unix::ext`
439 // `std::sys::unix::ext` -> `std::os`
441 // This is correct, as the visible parent of `std::sys::unix::ext` is in fact
444 // When printing the path to `CommandExt` and looking at the `cur_def_key` that
445 // corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
446 // to the parent - resulting in a mangled path like
447 // `std::os::ext::process::CommandExt`.
449 // Instead, we must detect that there was a re-export and instead print `unix`
450 // (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
451 // do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
452 // the visible parent (`std::os`). If these do not match, then we iterate over
453 // the children of the visible parent (as was done when computing
454 // `visible_parent_map`), looking for the specific child we currently have and then
455 // have access to the re-exported name.
456 DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
457 // Item might be re-exported several times, but filter for the one
458 // that's public and whose identifier isn't `_`.
461 .module_children(visible_parent)
463 .filter(|child| child.res.opt_def_id() == Some(def_id))
464 .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
465 .map(|child| child.ident.name);
467 if let Some(new_name) = reexport {
470 // There is no name that is public and isn't `_`, so bail.
471 return Ok((self, false));
474 // Re-exported `extern crate` (#43189).
475 DefPathData::CrateRoot => {
476 data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
480 debug!("try_print_visible_def_path: data={:?}", data);
482 if callers.contains(&visible_parent) {
483 return Ok((self, false));
485 callers.push(visible_parent);
486 // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
487 // knowing ahead of time whether the entire path will succeed or not.
488 // To support printers that do not implement `PrettyPrinter`, a `Vec` or
489 // linked list on the stack would need to be built, before any printing.
490 match self.try_print_visible_def_path_recur(visible_parent, callers)? {
491 (cx, false) => return Ok((cx, false)),
492 (cx, true) => self = cx,
496 Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
499 fn pretty_path_qualified(
502 trait_ref: Option<ty::TraitRef<'tcx>>,
503 ) -> Result<Self::Path, Self::Error> {
504 if trait_ref.is_none() {
505 // Inherent impls. Try to print `Foo::bar` for an inherent
506 // impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
507 // anything other than a simple path.
508 match self_ty.kind() {
517 return self_ty.print(self);
524 self.generic_delimiters(|mut cx| {
525 define_scoped_cx!(cx);
528 if let Some(trait_ref) = trait_ref {
529 p!(" as ", print(trait_ref.print_only_trait_path()));
535 fn pretty_path_append_impl(
537 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
539 trait_ref: Option<ty::TraitRef<'tcx>>,
540 ) -> Result<Self::Path, Self::Error> {
541 self = print_prefix(self)?;
543 self.generic_delimiters(|mut cx| {
544 define_scoped_cx!(cx);
547 if let Some(trait_ref) = trait_ref {
548 p!(print(trait_ref.print_only_trait_path()), " for ");
556 fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
557 define_scoped_cx!(self);
560 ty::Bool => p!("bool"),
561 ty::Char => p!("char"),
562 ty::Int(t) => p!(write("{}", t.name_str())),
563 ty::Uint(t) => p!(write("{}", t.name_str())),
564 ty::Float(t) => p!(write("{}", t.name_str())),
565 ty::RawPtr(ref tm) => {
569 hir::Mutability::Mut => "mut",
570 hir::Mutability::Not => "const",
575 ty::Ref(r, ty, mutbl) => {
577 if self.region_should_not_be_omitted(r) {
580 p!(print(ty::TypeAndMut { ty, mutbl }))
582 ty::Never => p!("!"),
583 ty::Tuple(ref tys) => {
584 p!("(", comma_sep(tys.iter()));
590 ty::FnDef(def_id, substs) => {
591 let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
592 p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
594 ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
595 ty::Infer(infer_ty) => {
596 let verbose = self.tcx().sess.verbose();
597 if let ty::TyVar(ty_vid) = infer_ty {
598 if let Some(name) = self.infer_ty_name(ty_vid) {
599 p!(write("{}", name))
602 p!(write("{:?}", infer_ty))
604 p!(write("{}", infer_ty))
608 if verbose { p!(write("{:?}", infer_ty)) } else { p!(write("{}", infer_ty)) }
611 ty::Error(_) => p!("[type error]"),
612 ty::Param(ref param_ty) => p!(write("{}", param_ty)),
613 ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
614 ty::BoundTyKind::Anon => self.pretty_print_bound_var(debruijn, bound_ty.var)?,
615 ty::BoundTyKind::Param(p) => p!(write("{}", p)),
617 ty::Adt(def, substs) => {
618 p!(print_def_path(def.did, substs));
620 ty::Dynamic(data, r) => {
621 let print_r = self.region_should_not_be_omitted(r);
625 p!("dyn ", print(data));
627 p!(" + ", print(r), ")");
630 ty::Foreign(def_id) => {
631 p!(print_def_path(def_id, &[]));
633 ty::Projection(ref data) => p!(print(data)),
634 ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
635 ty::Opaque(def_id, substs) => {
636 // FIXME(eddyb) print this with `print_def_path`.
637 // We use verbose printing in 'NO_QUERIES' mode, to
638 // avoid needing to call `predicates_of`. This should
639 // only affect certain debug messages (e.g. messages printed
640 // from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
641 // and should have no effect on any compiler output.
642 if self.tcx().sess.verbose() || NO_QUERIES.with(|q| q.get()) {
643 p!(write("Opaque({:?}, {:?})", def_id, substs));
647 return with_no_queries(|| {
648 let def_key = self.tcx().def_key(def_id);
649 if let Some(name) = def_key.disambiguated_data.data.get_opt_name() {
650 p!(write("{}", name));
651 // FIXME(eddyb) print this with `print_def_path`.
652 if !substs.is_empty() {
654 p!(generic_delimiters(|cx| cx.comma_sep(substs.iter())));
659 self.pretty_print_opaque_impl_type(def_id, substs)
662 ty::Str => p!("str"),
663 ty::Generator(did, substs, movability) => {
666 hir::Movability::Movable => {}
667 hir::Movability::Static => p!("static "),
670 if !self.tcx().sess.verbose() {
672 // FIXME(eddyb) should use `def_span`.
673 if let Some(did) = did.as_local() {
674 let span = self.tcx().def_span(did);
677 // This may end up in stderr diagnostics but it may also be emitted
678 // into MIR. Hence we use the remapped path if available
679 self.tcx().sess.source_map().span_to_embeddable_string(span)
682 p!(write("@"), print_def_path(did, substs));
685 p!(print_def_path(did, substs));
687 if !substs.as_generator().is_valid() {
690 self = self.comma_sep(substs.as_generator().upvar_tys())?;
694 if substs.as_generator().is_valid() {
695 p!(" ", print(substs.as_generator().witness()));
701 ty::GeneratorWitness(types) => {
702 p!(in_binder(&types));
704 ty::Closure(did, substs) => {
706 if !self.tcx().sess.verbose() {
707 p!(write("closure"));
708 // FIXME(eddyb) should use `def_span`.
709 if let Some(did) = did.as_local() {
710 if self.tcx().sess.opts.debugging_opts.span_free_formats {
711 p!("@", print_def_path(did.to_def_id(), substs));
713 let span = self.tcx().def_span(did);
716 // This may end up in stderr diagnostics but it may also be emitted
717 // into MIR. Hence we use the remapped path if available
718 self.tcx().sess.source_map().span_to_embeddable_string(span)
722 p!(write("@"), print_def_path(did, substs));
725 p!(print_def_path(did, substs));
726 if !substs.as_closure().is_valid() {
727 p!(" closure_substs=(unavailable)");
728 p!(write(" substs={:?}", substs));
730 p!(" closure_kind_ty=", print(substs.as_closure().kind_ty()));
732 " closure_sig_as_fn_ptr_ty=",
733 print(substs.as_closure().sig_as_fn_ptr_ty())
736 self = self.comma_sep(substs.as_closure().upvar_tys())?;
742 ty::Array(ty, sz) => {
743 p!("[", print(ty), "; ");
744 if self.tcx().sess.verbose() {
745 p!(write("{:?}", sz));
746 } else if let ty::ConstKind::Unevaluated(..) = sz.val {
747 // Do not try to evaluate unevaluated constants. If we are const evaluating an
748 // array length anon const, rustc will (with debug assertions) print the
749 // constant's path. Which will end up here again.
751 } else if let Some(n) = sz.val.try_to_bits(self.tcx().data_layout.pointer_size) {
753 } else if let ty::ConstKind::Param(param) = sz.val {
754 p!(write("{}", param));
760 ty::Slice(ty) => p!("[", print(ty), "]"),
766 fn pretty_print_opaque_impl_type(
769 substs: &'tcx ty::List<ty::GenericArg<'tcx>>,
770 ) -> Result<Self::Type, Self::Error> {
771 define_scoped_cx!(self);
773 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
774 // by looking up the projections associated with the def_id.
775 let bounds = self.tcx().explicit_item_bounds(def_id);
777 let mut traits = BTreeMap::new();
778 let mut fn_traits = BTreeMap::new();
779 let mut is_sized = false;
781 for (predicate, _) in bounds {
782 let predicate = predicate.subst(self.tcx(), substs);
783 let bound_predicate = predicate.kind();
785 match bound_predicate.skip_binder() {
786 ty::PredicateKind::Trait(pred) => {
787 let trait_ref = bound_predicate.rebind(pred.trait_ref);
789 // Don't print + Sized, but rather + ?Sized if absent.
790 if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
795 self.insert_trait_and_projection(trait_ref, None, &mut traits, &mut fn_traits);
797 ty::PredicateKind::Projection(pred) => {
798 let proj_ref = bound_predicate.rebind(pred);
799 let trait_ref = proj_ref.required_poly_trait_ref(self.tcx());
801 // Projection type entry -- the def-id for naming, and the ty.
802 let proj_ty = (proj_ref.projection_def_id(), proj_ref.ty());
804 self.insert_trait_and_projection(
815 let mut first = true;
816 // Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
817 let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !is_sized;
821 for (fn_once_trait_ref, entry) in fn_traits {
822 // Get the (single) generic ty (the args) of this FnOnce trait ref.
823 let generics = self.generic_args_to_print(
824 self.tcx().generics_of(fn_once_trait_ref.def_id()),
825 fn_once_trait_ref.skip_binder().substs,
828 match (entry.return_ty, generics[0].expect_ty()) {
829 // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
831 (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
832 let name = if entry.fn_trait_ref.is_some() {
834 } else if entry.fn_mut_trait_ref.is_some() {
841 write("{}", if first { " " } else { " + " }),
842 write("{}{}(", if paren_needed { "(" } else { "" }, name)
845 for (idx, ty) in arg_tys.tuple_fields().enumerate() {
853 if !return_ty.skip_binder().is_unit() {
854 p!("-> ", print(return_ty));
856 p!(write("{}", if paren_needed { ")" } else { "" }));
860 // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
861 // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
863 if entry.has_fn_once {
864 traits.entry(fn_once_trait_ref).or_default().extend(
865 // Group the return ty with its def id, if we had one.
868 .map(|ty| (self.tcx().lang_items().fn_once_output().unwrap(), ty)),
871 if let Some(trait_ref) = entry.fn_mut_trait_ref {
872 traits.entry(trait_ref).or_default();
874 if let Some(trait_ref) = entry.fn_trait_ref {
875 traits.entry(trait_ref).or_default();
881 // Print the rest of the trait types (that aren't Fn* family of traits)
882 for (trait_ref, assoc_items) in traits {
884 write("{}", if first { " " } else { " + " }),
885 print(trait_ref.skip_binder().print_only_trait_name())
888 let generics = self.generic_args_to_print(
889 self.tcx().generics_of(trait_ref.def_id()),
890 trait_ref.skip_binder().substs,
893 if !generics.is_empty() || !assoc_items.is_empty() {
895 let mut first = true;
901 p!(print(trait_ref.rebind(*ty)));
905 for (assoc_item_def_id, ty) in assoc_items {
909 p!(write("{} = ", self.tcx().associated_item(assoc_item_def_id).ident));
911 // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks
912 match ty.skip_binder().kind() {
913 ty::Projection(ty::ProjectionTy { item_def_id, .. })
914 if Some(*item_def_id) == self.tcx().lang_items().generator_return() =>
933 p!(write("{}?Sized", if first { " " } else { " + " }));
941 /// Insert the trait ref and optionally a projection type associated with it into either the
942 /// traits map or fn_traits map, depending on if the trait is in the Fn* family of traits.
943 fn insert_trait_and_projection(
945 trait_ref: ty::PolyTraitRef<'tcx>,
946 proj_ty: Option<(DefId, ty::Binder<'tcx, Ty<'tcx>>)>,
947 traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, BTreeMap<DefId, ty::Binder<'tcx, Ty<'tcx>>>>,
948 fn_traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, OpaqueFnEntry<'tcx>>,
950 let trait_def_id = trait_ref.def_id();
952 // If our trait_ref is FnOnce or any of its children, project it onto the parent FnOnce
953 // super-trait ref and record it there.
954 if let Some(fn_once_trait) = self.tcx().lang_items().fn_once_trait() {
955 // If we have a FnOnce, then insert it into
956 if trait_def_id == fn_once_trait {
957 let entry = fn_traits.entry(trait_ref).or_default();
958 // Optionally insert the return_ty as well.
959 if let Some((_, ty)) = proj_ty {
960 entry.return_ty = Some(ty);
962 entry.has_fn_once = true;
964 } else if Some(trait_def_id) == self.tcx().lang_items().fn_mut_trait() {
965 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
966 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
969 fn_traits.entry(super_trait_ref).or_default().fn_mut_trait_ref = Some(trait_ref);
971 } else if Some(trait_def_id) == self.tcx().lang_items().fn_trait() {
972 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
973 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
976 fn_traits.entry(super_trait_ref).or_default().fn_trait_ref = Some(trait_ref);
981 // Otherwise, just group our traits and projection types.
982 traits.entry(trait_ref).or_default().extend(proj_ty);
985 fn pretty_print_bound_var(
987 debruijn: ty::DebruijnIndex,
989 ) -> Result<(), Self::Error> {
990 if debruijn == ty::INNERMOST {
991 write!(self, "^{}", var.index())
993 write!(self, "^{}_{}", debruijn.index(), var.index())
997 fn infer_ty_name(&self, _: ty::TyVid) -> Option<String> {
1001 fn pretty_print_dyn_existential(
1003 predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
1004 ) -> Result<Self::DynExistential, Self::Error> {
1005 // Generate the main trait ref, including associated types.
1006 let mut first = true;
1008 if let Some(principal) = predicates.principal() {
1009 self = self.wrap_binder(&principal, |principal, mut cx| {
1010 define_scoped_cx!(cx);
1011 p!(print_def_path(principal.def_id, &[]));
1013 let mut resugared = false;
1015 // Special-case `Fn(...) -> ...` and resugar it.
1016 let fn_trait_kind = cx.tcx().fn_trait_kind_from_lang_item(principal.def_id);
1017 if !cx.tcx().sess.verbose() && fn_trait_kind.is_some() {
1018 if let ty::Tuple(ref args) = principal.substs.type_at(0).kind() {
1019 let mut projections = predicates.projection_bounds();
1020 if let (Some(proj), None) = (projections.next(), projections.next()) {
1021 let tys: Vec<_> = args.iter().map(|k| k.expect_ty()).collect();
1022 p!(pretty_fn_sig(&tys, false, proj.skip_binder().ty));
1028 // HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
1029 // in order to place the projections inside the `<...>`.
1031 // Use a type that can't appear in defaults of type parameters.
1032 let dummy_cx = cx.tcx().mk_ty_infer(ty::FreshTy(0));
1033 let principal = principal.with_self_ty(cx.tcx(), dummy_cx);
1035 let args = cx.generic_args_to_print(
1036 cx.tcx().generics_of(principal.def_id),
1040 // Don't print `'_` if there's no unerased regions.
1041 let print_regions = args.iter().any(|arg| match arg.unpack() {
1042 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
1045 let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
1046 GenericArgKind::Lifetime(_) => print_regions,
1049 let mut projections = predicates.projection_bounds();
1051 let arg0 = args.next();
1052 let projection0 = projections.next();
1053 if arg0.is_some() || projection0.is_some() {
1054 let args = arg0.into_iter().chain(args);
1055 let projections = projection0.into_iter().chain(projections);
1057 p!(generic_delimiters(|mut cx| {
1058 cx = cx.comma_sep(args)?;
1059 if arg0.is_some() && projection0.is_some() {
1062 cx.comma_sep(projections)
1072 define_scoped_cx!(self);
1075 // FIXME(eddyb) avoid printing twice (needed to ensure
1076 // that the auto traits are sorted *and* printed via cx).
1077 let mut auto_traits: Vec<_> =
1078 predicates.auto_traits().map(|did| (self.tcx().def_path_str(did), did)).collect();
1080 // The auto traits come ordered by `DefPathHash`. While
1081 // `DefPathHash` is *stable* in the sense that it depends on
1082 // neither the host nor the phase of the moon, it depends
1083 // "pseudorandomly" on the compiler version and the target.
1085 // To avoid that causing instabilities in compiletest
1086 // output, sort the auto-traits alphabetically.
1089 for (_, def_id) in auto_traits {
1095 p!(print_def_path(def_id, &[]));
1103 inputs: &[Ty<'tcx>],
1106 ) -> Result<Self, Self::Error> {
1107 define_scoped_cx!(self);
1109 p!("(", comma_sep(inputs.iter().copied()));
1111 if !inputs.is_empty() {
1117 if !output.is_unit() {
1118 p!(" -> ", print(output));
1124 fn pretty_print_const(
1126 ct: &'tcx ty::Const<'tcx>,
1128 ) -> Result<Self::Const, Self::Error> {
1129 define_scoped_cx!(self);
1131 if self.tcx().sess.verbose() {
1132 p!(write("Const({:?}: {:?})", ct.val, ct.ty));
1136 macro_rules! print_underscore {
1139 self = self.typed_value(
1144 |this| this.print_type(ct.ty),
1154 ty::ConstKind::Unevaluated(ty::Unevaluated {
1157 promoted: Some(promoted),
1159 p!(print_value_path(def.did, substs));
1160 p!(write("::{:?}", promoted));
1162 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted: None }) => {
1163 match self.tcx().def_kind(def.did) {
1164 DefKind::Static | DefKind::Const | DefKind::AssocConst => {
1165 p!(print_value_path(def.did, substs))
1169 let span = self.tcx().def_span(def.did);
1170 if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) {
1171 p!(write("{}", snip))
1181 ty::ConstKind::Infer(..) => print_underscore!(),
1182 ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
1183 ty::ConstKind::Value(value) => {
1184 return self.pretty_print_const_value(value, ct.ty, print_ty);
1187 ty::ConstKind::Bound(debruijn, bound_var) => {
1188 self.pretty_print_bound_var(debruijn, bound_var)?
1190 ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
1191 ty::ConstKind::Error(_) => p!("[const error]"),
1196 fn pretty_print_const_scalar(
1201 ) -> Result<Self::Const, Self::Error> {
1203 Scalar::Ptr(ptr, _size) => self.pretty_print_const_scalar_ptr(ptr, ty, print_ty),
1204 Scalar::Int(int) => self.pretty_print_const_scalar_int(int, ty, print_ty),
1208 fn pretty_print_const_scalar_ptr(
1213 ) -> Result<Self::Const, Self::Error> {
1214 define_scoped_cx!(self);
1216 let (alloc_id, offset) = ptr.into_parts();
1218 // Byte strings (&[u8; N])
1224 ty::TyS { kind: ty::Uint(ty::UintTy::U8), .. },
1226 val: ty::ConstKind::Value(ConstValue::Scalar(int)), ..
1232 ) => match self.tcx().get_global_alloc(alloc_id) {
1233 Some(GlobalAlloc::Memory(alloc)) => {
1234 let len = int.assert_bits(self.tcx().data_layout.pointer_size);
1235 let range = AllocRange { start: offset, size: Size::from_bytes(len) };
1236 if let Ok(byte_str) = alloc.get_bytes(&self.tcx(), range) {
1237 p!(pretty_print_byte_str(byte_str))
1239 p!("<too short allocation>")
1242 // FIXME: for statics and functions, we could in principle print more detail.
1243 Some(GlobalAlloc::Static(def_id)) => p!(write("<static({:?})>", def_id)),
1244 Some(GlobalAlloc::Function(_)) => p!("<function>"),
1245 None => p!("<dangling pointer>"),
1248 // FIXME: We should probably have a helper method to share code with the "Byte strings"
1249 // printing above (which also has to handle pointers to all sorts of things).
1250 match self.tcx().get_global_alloc(alloc_id) {
1251 Some(GlobalAlloc::Function(instance)) => {
1252 self = self.typed_value(
1253 |this| this.print_value_path(instance.def_id(), instance.substs),
1254 |this| this.print_type(ty),
1258 _ => self = self.pretty_print_const_pointer(ptr, ty, print_ty)?,
1261 // Any pointer values not covered by a branch above
1263 self = self.pretty_print_const_pointer(ptr, ty, print_ty)?;
1269 fn pretty_print_const_scalar_int(
1274 ) -> Result<Self::Const, Self::Error> {
1275 define_scoped_cx!(self);
1279 ty::Bool if int == ScalarInt::FALSE => p!("false"),
1280 ty::Bool if int == ScalarInt::TRUE => p!("true"),
1282 ty::Float(ty::FloatTy::F32) => {
1283 p!(write("{}f32", Single::try_from(int).unwrap()))
1285 ty::Float(ty::FloatTy::F64) => {
1286 p!(write("{}f64", Double::try_from(int).unwrap()))
1289 ty::Uint(_) | ty::Int(_) => {
1291 ConstInt::new(int, matches!(ty.kind(), ty::Int(_)), ty.is_ptr_sized_integral());
1292 if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
1295 ty::Char if char::try_from(int).is_ok() => {
1296 p!(write("{:?}", char::try_from(int).unwrap()))
1299 ty::Ref(..) | ty::RawPtr(_) | ty::FnPtr(_) => {
1300 let data = int.assert_bits(self.tcx().data_layout.pointer_size);
1301 self = self.typed_value(
1303 write!(this, "0x{:x}", data)?;
1306 |this| this.print_type(ty),
1310 // For function type zsts just printing the path is enough
1311 ty::FnDef(d, s) if int == ScalarInt::ZST => {
1312 p!(print_value_path(*d, s))
1314 // Nontrivial types with scalar bit representation
1316 let print = |mut this: Self| {
1317 if int.size() == Size::ZERO {
1318 write!(this, "transmute(())")?;
1320 write!(this, "transmute(0x{:x})", int)?;
1324 self = if print_ty {
1325 self.typed_value(print, |this| this.print_type(ty), ": ")?
1334 /// This is overridden for MIR printing because we only want to hide alloc ids from users, not
1335 /// from MIR where it is actually useful.
1336 fn pretty_print_const_pointer<Tag: Provenance>(
1341 ) -> Result<Self::Const, Self::Error> {
1345 this.write_str("&_")?;
1348 |this| this.print_type(ty),
1352 self.write_str("&_")?;
1357 fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
1358 define_scoped_cx!(self);
1360 for &c in byte_str {
1361 for e in std::ascii::escape_default(c) {
1362 self.write_char(e as char)?;
1369 fn pretty_print_const_value(
1371 ct: ConstValue<'tcx>,
1374 ) -> Result<Self::Const, Self::Error> {
1375 define_scoped_cx!(self);
1377 if self.tcx().sess.verbose() {
1378 p!(write("ConstValue({:?}: ", ct), print(ty), ")");
1382 let u8_type = self.tcx().types.u8;
1384 match (ct, ty.kind()) {
1385 // Byte/string slices, printed as (byte) string literals.
1387 ConstValue::Slice { data, start, end },
1388 ty::Ref(_, ty::TyS { kind: ty::Slice(t), .. }, _),
1389 ) if *t == u8_type => {
1390 // The `inspect` here is okay since we checked the bounds, and there are
1391 // no relocations (we have an active slice reference here). We don't use
1392 // this result to affect interpreter execution.
1393 let byte_str = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1394 self.pretty_print_byte_str(byte_str)
1397 ConstValue::Slice { data, start, end },
1398 ty::Ref(_, ty::TyS { kind: ty::Str, .. }, _),
1400 // The `inspect` here is okay since we checked the bounds, and there are no
1401 // relocations (we have an active `str` reference here). We don't use this
1402 // result to affect interpreter execution.
1403 let slice = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1404 let s = std::str::from_utf8(slice).expect("non utf8 str from miri");
1405 p!(write("{:?}", s));
1408 (ConstValue::ByRef { alloc, offset }, ty::Array(t, n)) if *t == u8_type => {
1409 let n = n.val.try_to_bits(self.tcx().data_layout.pointer_size).unwrap();
1410 // cast is ok because we already checked for pointer size (32 or 64 bit) above
1411 let range = AllocRange { start: offset, size: Size::from_bytes(n) };
1413 let byte_str = alloc.get_bytes(&self.tcx(), range).unwrap();
1415 p!(pretty_print_byte_str(byte_str));
1419 // Aggregates, printed as array/tuple/struct/variant construction syntax.
1421 // NB: the `has_param_types_or_consts` check ensures that we can use
1422 // the `destructure_const` query with an empty `ty::ParamEnv` without
1423 // introducing ICEs (e.g. via `layout_of`) from missing bounds.
1424 // E.g. `transmute([0usize; 2]): (u8, *mut T)` needs to know `T: Sized`
1425 // to be able to destructure the tuple into `(0u8, *mut T)
1427 // FIXME(eddyb) for `--emit=mir`/`-Z dump-mir`, we should provide the
1428 // correct `ty::ParamEnv` to allow printing *all* constant values.
1429 (_, ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) if !ty.has_param_types_or_consts() => {
1430 let contents = self.tcx().destructure_const(
1431 ty::ParamEnv::reveal_all()
1432 .and(self.tcx().mk_const(ty::Const { val: ty::ConstKind::Value(ct), ty })),
1434 let fields = contents.fields.iter().copied();
1438 p!("[", comma_sep(fields), "]");
1441 p!("(", comma_sep(fields));
1442 if contents.fields.len() == 1 {
1447 ty::Adt(def, _) if def.variants.is_empty() => {
1448 self = self.typed_value(
1450 write!(this, "unreachable()")?;
1453 |this| this.print_type(ty),
1457 ty::Adt(def, substs) => {
1459 contents.variant.expect("destructed const of adt without variant idx");
1460 let variant_def = &def.variants[variant_idx];
1461 p!(print_value_path(variant_def.def_id, substs));
1463 match variant_def.ctor_kind {
1464 CtorKind::Const => {}
1466 p!("(", comma_sep(fields), ")");
1468 CtorKind::Fictive => {
1470 let mut first = true;
1471 for (field_def, field) in iter::zip(&variant_def.fields, fields) {
1475 p!(write("{}: ", field_def.name), print(field));
1482 _ => unreachable!(),
1488 (ConstValue::Scalar(scalar), _) => self.pretty_print_const_scalar(scalar, ty, print_ty),
1490 // FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
1491 // their fields instead of just dumping the memory.
1494 p!(write("{:?}", ct));
1496 p!(": ", print(ty));
1504 // HACK(eddyb) boxed to avoid moving around a large struct by-value.
1505 pub struct FmtPrinter<'a, 'tcx, F>(Box<FmtPrinterData<'a, 'tcx, F>>);
1507 pub struct FmtPrinterData<'a, 'tcx, F> {
1513 pub print_alloc_ids: bool,
1515 used_region_names: FxHashSet<Symbol>,
1516 region_index: usize,
1517 binder_depth: usize,
1518 printed_type_count: usize,
1520 pub region_highlight_mode: RegionHighlightMode,
1522 pub name_resolver: Option<Box<&'a dyn Fn(ty::TyVid) -> Option<String>>>,
1525 impl<'a, 'tcx, F> Deref for FmtPrinter<'a, 'tcx, F> {
1526 type Target = FmtPrinterData<'a, 'tcx, F>;
1527 fn deref(&self) -> &Self::Target {
1532 impl<F> DerefMut for FmtPrinter<'_, '_, F> {
1533 fn deref_mut(&mut self) -> &mut Self::Target {
1538 impl<'a, 'tcx, F> FmtPrinter<'a, 'tcx, F> {
1539 pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
1540 FmtPrinter(Box::new(FmtPrinterData {
1544 in_value: ns == Namespace::ValueNS,
1545 print_alloc_ids: false,
1546 used_region_names: Default::default(),
1549 printed_type_count: 0,
1550 region_highlight_mode: RegionHighlightMode::default(),
1551 name_resolver: None,
1556 // HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
1557 // (but also some things just print a `DefId` generally so maybe we need this?)
1558 fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
1559 match tcx.def_key(def_id).disambiguated_data.data {
1560 DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
1564 DefPathData::ValueNs(..)
1565 | DefPathData::AnonConst
1566 | DefPathData::ClosureExpr
1567 | DefPathData::Ctor => Namespace::ValueNS,
1569 DefPathData::MacroNs(..) => Namespace::MacroNS,
1571 _ => Namespace::TypeNS,
1575 impl<'t> TyCtxt<'t> {
1576 /// Returns a string identifying this `DefId`. This string is
1577 /// suitable for user output.
1578 pub fn def_path_str(self, def_id: DefId) -> String {
1579 self.def_path_str_with_substs(def_id, &[])
1582 pub fn def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String {
1583 let ns = guess_def_namespace(self, def_id);
1584 debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
1585 let mut s = String::new();
1586 let _ = FmtPrinter::new(self, &mut s, ns).print_def_path(def_id, substs);
1591 impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
1592 fn write_str(&mut self, s: &str) -> fmt::Result {
1593 self.fmt.write_str(s)
1597 impl<'tcx, F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
1598 type Error = fmt::Error;
1603 type DynExistential = Self;
1606 fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
1613 substs: &'tcx [GenericArg<'tcx>],
1614 ) -> Result<Self::Path, Self::Error> {
1615 define_scoped_cx!(self);
1617 if substs.is_empty() {
1618 match self.try_print_trimmed_def_path(def_id)? {
1619 (cx, true) => return Ok(cx),
1620 (cx, false) => self = cx,
1623 match self.try_print_visible_def_path(def_id)? {
1624 (cx, true) => return Ok(cx),
1625 (cx, false) => self = cx,
1629 let key = self.tcx.def_key(def_id);
1630 if let DefPathData::Impl = key.disambiguated_data.data {
1631 // Always use types for non-local impls, where types are always
1632 // available, and filename/line-number is mostly uninteresting.
1633 let use_types = !def_id.is_local() || {
1634 // Otherwise, use filename/line-number if forced.
1635 let force_no_types = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
1640 // If no type info is available, fall back to
1641 // pretty printing some span information. This should
1642 // only occur very early in the compiler pipeline.
1643 let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
1644 let span = self.tcx.def_span(def_id);
1646 self = self.print_def_path(parent_def_id, &[])?;
1648 // HACK(eddyb) copy of `path_append` to avoid
1649 // constructing a `DisambiguatedDefPathData`.
1650 if !self.empty_path {
1651 write!(self, "::")?;
1656 // This may end up in stderr diagnostics but it may also be emitted
1657 // into MIR. Hence we use the remapped path if available
1658 self.tcx.sess.source_map().span_to_embeddable_string(span)
1660 self.empty_path = false;
1666 self.default_print_def_path(def_id, substs)
1669 fn print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
1670 self.pretty_print_region(region)
1673 fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
1674 let type_length_limit = self.tcx.type_length_limit();
1675 if type_length_limit.value_within_limit(self.printed_type_count) {
1676 self.printed_type_count += 1;
1677 self.pretty_print_type(ty)
1679 write!(self, "...")?;
1684 fn print_dyn_existential(
1686 predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
1687 ) -> Result<Self::DynExistential, Self::Error> {
1688 self.pretty_print_dyn_existential(predicates)
1691 fn print_const(self, ct: &'tcx ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
1692 self.pretty_print_const(ct, true)
1695 fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
1696 self.empty_path = true;
1697 if cnum == LOCAL_CRATE {
1698 if self.tcx.sess.rust_2018() {
1699 // We add the `crate::` keyword on Rust 2018, only when desired.
1700 if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
1701 write!(self, "{}", kw::Crate)?;
1702 self.empty_path = false;
1706 write!(self, "{}", self.tcx.crate_name(cnum))?;
1707 self.empty_path = false;
1715 trait_ref: Option<ty::TraitRef<'tcx>>,
1716 ) -> Result<Self::Path, Self::Error> {
1717 self = self.pretty_path_qualified(self_ty, trait_ref)?;
1718 self.empty_path = false;
1722 fn path_append_impl(
1724 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1725 _disambiguated_data: &DisambiguatedDefPathData,
1727 trait_ref: Option<ty::TraitRef<'tcx>>,
1728 ) -> Result<Self::Path, Self::Error> {
1729 self = self.pretty_path_append_impl(
1731 cx = print_prefix(cx)?;
1741 self.empty_path = false;
1747 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1748 disambiguated_data: &DisambiguatedDefPathData,
1749 ) -> Result<Self::Path, Self::Error> {
1750 self = print_prefix(self)?;
1752 // Skip `::{{extern}}` blocks and `::{{constructor}}` on tuple/unit structs.
1753 if let DefPathData::ForeignMod | DefPathData::Ctor = disambiguated_data.data {
1757 let name = disambiguated_data.data.name();
1758 if !self.empty_path {
1759 write!(self, "::")?;
1762 if let DefPathDataName::Named(name) = name {
1763 if Ident::with_dummy_span(name).is_raw_guess() {
1764 write!(self, "r#")?;
1768 let verbose = self.tcx.sess.verbose();
1769 disambiguated_data.fmt_maybe_verbose(&mut self, verbose)?;
1771 self.empty_path = false;
1776 fn path_generic_args(
1778 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1779 args: &[GenericArg<'tcx>],
1780 ) -> Result<Self::Path, Self::Error> {
1781 self = print_prefix(self)?;
1783 // Don't print `'_` if there's no unerased regions.
1784 let print_regions = self.tcx.sess.verbose()
1785 || args.iter().any(|arg| match arg.unpack() {
1786 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
1789 let args = args.iter().cloned().filter(|arg| match arg.unpack() {
1790 GenericArgKind::Lifetime(_) => print_regions,
1794 if args.clone().next().is_some() {
1796 write!(self, "::")?;
1798 self.generic_delimiters(|cx| cx.comma_sep(args))
1805 impl<'tcx, F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
1806 fn infer_ty_name(&self, id: ty::TyVid) -> Option<String> {
1807 self.0.name_resolver.as_ref().and_then(|func| func(id))
1810 fn print_value_path(
1813 substs: &'tcx [GenericArg<'tcx>],
1814 ) -> Result<Self::Path, Self::Error> {
1815 let was_in_value = std::mem::replace(&mut self.in_value, true);
1816 self = self.print_def_path(def_id, substs)?;
1817 self.in_value = was_in_value;
1822 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
1824 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
1826 self.pretty_in_binder(value)
1829 fn wrap_binder<T, C: Fn(&T, Self) -> Result<Self, Self::Error>>(
1831 value: &ty::Binder<'tcx, T>,
1833 ) -> Result<Self, Self::Error>
1835 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
1837 self.pretty_wrap_binder(value, f)
1842 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1843 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
1845 ) -> Result<Self::Const, Self::Error> {
1846 self.write_str("{")?;
1848 self.write_str(conversion)?;
1849 let was_in_value = std::mem::replace(&mut self.in_value, false);
1851 self.in_value = was_in_value;
1852 self.write_str("}")?;
1856 fn generic_delimiters(
1858 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1859 ) -> Result<Self, Self::Error> {
1862 let was_in_value = std::mem::replace(&mut self.in_value, false);
1863 let mut inner = f(self)?;
1864 inner.in_value = was_in_value;
1866 write!(inner, ">")?;
1870 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool {
1871 let highlight = self.region_highlight_mode;
1872 if highlight.region_highlighted(region).is_some() {
1876 if self.tcx.sess.verbose() {
1880 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1883 ty::ReEarlyBound(ref data) => {
1884 data.name != kw::Empty && data.name != kw::UnderscoreLifetime
1887 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
1888 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1889 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1890 if let ty::BrNamed(_, name) = br {
1891 if name != kw::Empty && name != kw::UnderscoreLifetime {
1896 if let Some((region, _)) = highlight.highlight_bound_region {
1905 ty::ReVar(_) if identify_regions => true,
1907 ty::ReVar(_) | ty::ReErased => false,
1909 ty::ReStatic | ty::ReEmpty(_) => true,
1913 fn pretty_print_const_pointer<Tag: Provenance>(
1918 ) -> Result<Self::Const, Self::Error> {
1919 let print = |mut this: Self| {
1920 define_scoped_cx!(this);
1921 if this.print_alloc_ids {
1922 p!(write("{:?}", p));
1929 self.typed_value(print, |this| this.print_type(ty), ": ")
1936 // HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
1937 impl<F: fmt::Write> FmtPrinter<'_, '_, F> {
1938 pub fn pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error> {
1939 define_scoped_cx!(self);
1941 // Watch out for region highlights.
1942 let highlight = self.region_highlight_mode;
1943 if let Some(n) = highlight.region_highlighted(region) {
1944 p!(write("'{}", n));
1948 if self.tcx.sess.verbose() {
1949 p!(write("{:?}", region));
1953 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1955 // These printouts are concise. They do not contain all the information
1956 // the user might want to diagnose an error, but there is basically no way
1957 // to fit that into a short string. Hence the recommendation to use
1958 // `explain_region()` or `note_and_explain_region()`.
1960 ty::ReEarlyBound(ref data) => {
1961 if data.name != kw::Empty {
1962 p!(write("{}", data.name));
1966 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
1967 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1968 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1969 if let ty::BrNamed(_, name) = br {
1970 if name != kw::Empty && name != kw::UnderscoreLifetime {
1971 p!(write("{}", name));
1976 if let Some((region, counter)) = highlight.highlight_bound_region {
1978 p!(write("'{}", counter));
1983 ty::ReVar(region_vid) if identify_regions => {
1984 p!(write("{:?}", region_vid));
1993 ty::ReEmpty(ty::UniverseIndex::ROOT) => {
1997 ty::ReEmpty(ui) => {
1998 p!(write("'<empty:{:?}>", ui));
2009 /// Folds through bound vars and placeholders, naming them
2010 struct RegionFolder<'a, 'tcx> {
2012 current_index: ty::DebruijnIndex,
2013 region_map: BTreeMap<ty::BoundRegion, ty::Region<'tcx>>,
2014 name: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a),
2017 impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> {
2018 fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
2022 fn fold_binder<T: TypeFoldable<'tcx>>(
2024 t: ty::Binder<'tcx, T>,
2025 ) -> ty::Binder<'tcx, T> {
2026 self.current_index.shift_in(1);
2027 let t = t.super_fold_with(self);
2028 self.current_index.shift_out(1);
2032 fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
2034 _ if t.has_vars_bound_at_or_above(self.current_index) || t.has_placeholders() => {
2035 return t.super_fold_with(self);
2042 fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
2043 let name = &mut self.name;
2044 let region = match *r {
2045 ty::ReLateBound(_, br) => self.region_map.entry(br).or_insert_with(|| name(br)),
2046 ty::RePlaceholder(ty::PlaceholderRegion { name: kind, .. }) => {
2047 // If this is an anonymous placeholder, don't rename. Otherwise, in some
2048 // async fns, we get a `for<'r> Send` bound
2050 ty::BrAnon(_) | ty::BrEnv => r,
2052 // Index doesn't matter, since this is just for naming and these never get bound
2053 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind };
2054 self.region_map.entry(br).or_insert_with(|| name(br))
2060 if let ty::ReLateBound(debruijn1, br) = *region {
2061 assert_eq!(debruijn1, ty::INNERMOST);
2062 self.tcx.mk_region(ty::ReLateBound(self.current_index, br))
2069 // HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
2070 // `region_index` and `used_region_names`.
2071 impl<'tcx, F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
2072 pub fn name_all_regions<T>(
2074 value: &ty::Binder<'tcx, T>,
2075 ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
2077 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2079 fn name_by_region_index(index: usize) -> Symbol {
2081 0 => Symbol::intern("'r"),
2082 1 => Symbol::intern("'s"),
2083 i => Symbol::intern(&format!("'t{}", i - 2)),
2087 // Replace any anonymous late-bound regions with named
2088 // variants, using new unique identifiers, so that we can
2089 // clearly differentiate between named and unnamed regions in
2090 // the output. We'll probably want to tweak this over time to
2091 // decide just how much information to give.
2092 if self.binder_depth == 0 {
2093 self.prepare_late_bound_region_info(value);
2096 let mut empty = true;
2097 let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
2104 let _ = write!(cx, "{}", w);
2106 let do_continue = |cx: &mut Self, cont: Symbol| {
2107 let _ = write!(cx, "{}", cont);
2110 define_scoped_cx!(self);
2112 let mut region_index = self.region_index;
2113 // If we want to print verbosly, then print *all* binders, even if they
2114 // aren't named. Eventually, we might just want this as the default, but
2115 // this is not *quite* right and changes the ordering of some output
2117 let (new_value, map) = if self.tcx().sess.verbose() {
2118 // anon index + 1 (BrEnv takes 0) -> name
2119 let mut region_map: BTreeMap<u32, Symbol> = BTreeMap::default();
2120 let bound_vars = value.bound_vars();
2121 for var in bound_vars {
2123 ty::BoundVariableKind::Region(ty::BrNamed(_, name)) => {
2124 start_or_continue(&mut self, "for<", ", ");
2125 do_continue(&mut self, name);
2127 ty::BoundVariableKind::Region(ty::BrAnon(i)) => {
2128 start_or_continue(&mut self, "for<", ", ");
2130 let name = name_by_region_index(region_index);
2132 if !self.used_region_names.contains(&name) {
2136 do_continue(&mut self, name);
2137 region_map.insert(i + 1, name);
2139 ty::BoundVariableKind::Region(ty::BrEnv) => {
2140 start_or_continue(&mut self, "for<", ", ");
2142 let name = name_by_region_index(region_index);
2144 if !self.used_region_names.contains(&name) {
2148 do_continue(&mut self, name);
2149 region_map.insert(0, name);
2154 start_or_continue(&mut self, "", "> ");
2156 self.tcx.replace_late_bound_regions(value.clone(), |br| {
2157 let kind = match br.kind {
2158 ty::BrNamed(_, _) => br.kind,
2160 let name = region_map[&(i + 1)];
2161 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2164 let name = region_map[&0];
2165 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2168 self.tcx.mk_region(ty::ReLateBound(
2170 ty::BoundRegion { var: br.var, kind },
2175 let mut name = |br: ty::BoundRegion| {
2176 start_or_continue(&mut self, "for<", ", ");
2177 let kind = match br.kind {
2178 ty::BrNamed(_, name) => {
2179 do_continue(&mut self, name);
2182 ty::BrAnon(_) | ty::BrEnv => {
2184 let name = name_by_region_index(region_index);
2186 if !self.used_region_names.contains(&name) {
2190 do_continue(&mut self, name);
2191 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2194 tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { var: br.var, kind }))
2196 let mut folder = RegionFolder {
2198 current_index: ty::INNERMOST,
2200 region_map: BTreeMap::new(),
2202 let new_value = value.clone().skip_binder().fold_with(&mut folder);
2203 let region_map = folder.region_map;
2204 start_or_continue(&mut self, "", "> ");
2205 (new_value, region_map)
2208 self.binder_depth += 1;
2209 self.region_index = region_index;
2210 Ok((self, new_value, map))
2213 pub fn pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error>
2215 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2217 let old_region_index = self.region_index;
2218 let (new, new_value, _) = self.name_all_regions(value)?;
2219 let mut inner = new_value.print(new)?;
2220 inner.region_index = old_region_index;
2221 inner.binder_depth -= 1;
2225 pub fn pretty_wrap_binder<T, C: Fn(&T, Self) -> Result<Self, fmt::Error>>(
2227 value: &ty::Binder<'tcx, T>,
2229 ) -> Result<Self, fmt::Error>
2231 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2233 let old_region_index = self.region_index;
2234 let (new, new_value, _) = self.name_all_regions(value)?;
2235 let mut inner = f(&new_value, new)?;
2236 inner.region_index = old_region_index;
2237 inner.binder_depth -= 1;
2241 #[instrument(skip(self), level = "debug")]
2242 fn prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
2244 T: TypeFoldable<'tcx>,
2246 struct LateBoundRegionNameCollector<'a, 'tcx> {
2247 used_region_names: &'a mut FxHashSet<Symbol>,
2248 type_collector: SsoHashSet<Ty<'tcx>>,
2251 impl<'tcx> ty::fold::TypeVisitor<'tcx> for LateBoundRegionNameCollector<'_, 'tcx> {
2254 #[instrument(skip(self), level = "trace")]
2255 fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
2256 trace!("address: {:p}", r);
2257 if let ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrNamed(_, name), .. }) = *r {
2258 self.used_region_names.insert(name);
2259 } else if let ty::RePlaceholder(ty::PlaceholderRegion {
2260 name: ty::BrNamed(_, name),
2264 self.used_region_names.insert(name);
2266 r.super_visit_with(self)
2269 // We collect types in order to prevent really large types from compiling for
2270 // a really long time. See issue #83150 for why this is necessary.
2271 #[instrument(skip(self), level = "trace")]
2272 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
2273 let not_previously_inserted = self.type_collector.insert(ty);
2274 if not_previously_inserted {
2275 ty.super_visit_with(self)
2277 ControlFlow::CONTINUE
2282 self.used_region_names.clear();
2283 let mut collector = LateBoundRegionNameCollector {
2284 used_region_names: &mut self.used_region_names,
2285 type_collector: SsoHashSet::new(),
2287 value.visit_with(&mut collector);
2288 self.region_index = 0;
2292 impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
2294 T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
2297 type Error = P::Error;
2298 fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
2303 impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
2305 T: Print<'tcx, P, Output = P, Error = P::Error>,
2306 U: Print<'tcx, P, Output = P, Error = P::Error>,
2309 type Error = P::Error;
2310 fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
2311 define_scoped_cx!(cx);
2312 p!(print(self.0), ": ", print(self.1));
2317 macro_rules! forward_display_to_print {
2319 // Some of the $ty arguments may not actually use 'tcx
2320 $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
2321 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2322 ty::tls::with(|tcx| {
2324 .expect("could not lift for printing")
2325 .print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
2333 macro_rules! define_print_and_forward_display {
2334 (($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
2335 $(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
2337 type Error = fmt::Error;
2338 fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
2339 #[allow(unused_mut)]
2341 define_scoped_cx!($cx);
2343 #[allow(unreachable_code)]
2348 forward_display_to_print!($($ty),+);
2352 // HACK(eddyb) this is separate because `ty::RegionKind` doesn't need lifting.
2353 impl fmt::Display for ty::RegionKind {
2354 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2355 ty::tls::with(|tcx| {
2356 self.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
2362 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2363 /// the trait path. That is, it will print `Trait<U>` instead of
2364 /// `<T as Trait<U>>`.
2365 #[derive(Copy, Clone, TypeFoldable, Lift)]
2366 pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
2368 impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
2369 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2370 fmt::Display::fmt(self, f)
2374 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2375 /// the trait name. That is, it will print `Trait` instead of
2376 /// `<T as Trait<U>>`.
2377 #[derive(Copy, Clone, TypeFoldable, Lift)]
2378 pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
2380 impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
2381 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2382 fmt::Display::fmt(self, f)
2386 impl<'tcx> ty::TraitRef<'tcx> {
2387 pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
2388 TraitRefPrintOnlyTraitPath(self)
2391 pub fn print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx> {
2392 TraitRefPrintOnlyTraitName(self)
2396 impl<'tcx> ty::Binder<'tcx, ty::TraitRef<'tcx>> {
2397 pub fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
2398 self.map_bound(|tr| tr.print_only_trait_path())
2402 forward_display_to_print! {
2404 &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
2405 &'tcx ty::Const<'tcx>,
2407 // HACK(eddyb) these are exhaustive instead of generic,
2408 // because `for<'tcx>` isn't possible yet.
2409 ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>,
2410 ty::Binder<'tcx, ty::TraitRef<'tcx>>,
2411 ty::Binder<'tcx, ty::ExistentialTraitRef<'tcx>>,
2412 ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>,
2413 ty::Binder<'tcx, TraitRefPrintOnlyTraitName<'tcx>>,
2414 ty::Binder<'tcx, ty::FnSig<'tcx>>,
2415 ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,
2416 ty::Binder<'tcx, ty::SubtypePredicate<'tcx>>,
2417 ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
2418 ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
2419 ty::Binder<'tcx, ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
2421 ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
2422 ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
2425 define_print_and_forward_display! {
2428 &'tcx ty::List<Ty<'tcx>> {
2429 p!("{{", comma_sep(self.iter()), "}}")
2432 ty::TypeAndMut<'tcx> {
2433 p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
2436 ty::ExistentialTraitRef<'tcx> {
2437 // Use a type that can't appear in defaults of type parameters.
2438 let dummy_self = cx.tcx().mk_ty_infer(ty::FreshTy(0));
2439 let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
2440 p!(print(trait_ref.print_only_trait_path()))
2443 ty::ExistentialProjection<'tcx> {
2444 let name = cx.tcx().associated_item(self.item_def_id).ident;
2445 p!(write("{} = ", name), print(self.ty))
2448 ty::ExistentialPredicate<'tcx> {
2450 ty::ExistentialPredicate::Trait(x) => p!(print(x)),
2451 ty::ExistentialPredicate::Projection(x) => p!(print(x)),
2452 ty::ExistentialPredicate::AutoTrait(def_id) => {
2453 p!(print_def_path(def_id, &[]));
2459 p!(write("{}", self.unsafety.prefix_str()));
2461 if self.abi != Abi::Rust {
2462 p!(write("extern {} ", self.abi));
2465 p!("fn", pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
2468 ty::TraitRef<'tcx> {
2469 p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
2472 TraitRefPrintOnlyTraitPath<'tcx> {
2473 p!(print_def_path(self.0.def_id, self.0.substs));
2476 TraitRefPrintOnlyTraitName<'tcx> {
2477 p!(print_def_path(self.0.def_id, &[]));
2481 p!(write("{}", self.name))
2485 p!(write("{}", self.name))
2488 ty::SubtypePredicate<'tcx> {
2489 p!(print(self.a), " <: ", print(self.b))
2492 ty::CoercePredicate<'tcx> {
2493 p!(print(self.a), " -> ", print(self.b))
2496 ty::TraitPredicate<'tcx> {
2497 p!(print(self.trait_ref.self_ty()), ": ",
2498 print(self.trait_ref.print_only_trait_path()))
2501 ty::ProjectionPredicate<'tcx> {
2502 p!(print(self.projection_ty), " == ", print(self.ty))
2505 ty::ProjectionTy<'tcx> {
2506 p!(print_def_path(self.item_def_id, self.substs));
2511 ty::ClosureKind::Fn => p!("Fn"),
2512 ty::ClosureKind::FnMut => p!("FnMut"),
2513 ty::ClosureKind::FnOnce => p!("FnOnce"),
2517 ty::Predicate<'tcx> {
2518 let binder = self.kind();
2522 ty::PredicateKind<'tcx> {
2524 ty::PredicateKind::Trait(ref data) => {
2527 ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
2528 ty::PredicateKind::Coerce(predicate) => p!(print(predicate)),
2529 ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)),
2530 ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)),
2531 ty::PredicateKind::Projection(predicate) => p!(print(predicate)),
2532 ty::PredicateKind::WellFormed(arg) => p!(print(arg), " well-formed"),
2533 ty::PredicateKind::ObjectSafe(trait_def_id) => {
2534 p!("the trait `", print_def_path(trait_def_id, &[]), "` is object-safe")
2536 ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => {
2538 print_value_path(closure_def_id, &[]),
2539 write("` implements the trait `{}`", kind))
2541 ty::PredicateKind::ConstEvaluatable(uv) => {
2542 p!("the constant `", print_value_path(uv.def.did, uv.substs), "` can be evaluated")
2544 ty::PredicateKind::ConstEquate(c1, c2) => {
2545 p!("the constant `", print(c1), "` equals `", print(c2), "`")
2547 ty::PredicateKind::TypeWellFormedFromEnv(ty) => {
2548 p!("the type `", print(ty), "` is found in the environment")
2554 match self.unpack() {
2555 GenericArgKind::Lifetime(lt) => p!(print(lt)),
2556 GenericArgKind::Type(ty) => p!(print(ty)),
2557 GenericArgKind::Const(ct) => p!(print(ct)),
2562 fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId)) {
2563 // Iterate all local crate items no matter where they are defined.
2564 let hir = tcx.hir();
2565 for item in hir.items() {
2566 if item.ident.name.as_str().is_empty() || matches!(item.kind, ItemKind::Use(_, _)) {
2570 let def_id = item.def_id.to_def_id();
2571 let ns = tcx.def_kind(def_id).ns().unwrap_or(Namespace::TypeNS);
2572 collect_fn(&item.ident, ns, def_id);
2575 // Now take care of extern crate items.
2576 let queue = &mut Vec::new();
2577 let mut seen_defs: DefIdSet = Default::default();
2579 for &cnum in tcx.crates(()).iter() {
2580 let def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX };
2582 // Ignore crates that are not direct dependencies.
2583 match tcx.extern_crate(def_id) {
2585 Some(extern_crate) => {
2586 if !extern_crate.is_direct() {
2595 // Iterate external crate defs but be mindful about visibility
2596 while let Some(def) = queue.pop() {
2597 for child in tcx.module_children(def).iter() {
2598 if !child.vis.is_public() {
2603 def::Res::Def(DefKind::AssocTy, _) => {}
2604 def::Res::Def(DefKind::TyAlias, _) => {}
2605 def::Res::Def(defkind, def_id) => {
2606 if let Some(ns) = defkind.ns() {
2607 collect_fn(&child.ident, ns, def_id);
2610 if matches!(defkind, DefKind::Mod | DefKind::Enum | DefKind::Trait)
2611 && seen_defs.insert(def_id)
2622 /// The purpose of this function is to collect public symbols names that are unique across all
2623 /// crates in the build. Later, when printing about types we can use those names instead of the
2624 /// full exported path to them.
2626 /// So essentially, if a symbol name can only be imported from one place for a type, and as
2627 /// long as it was not glob-imported anywhere in the current crate, we can trim its printed
2628 /// path and print only the name.
2630 /// This has wide implications on error messages with types, for example, shortening
2631 /// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere.
2633 /// The implementation uses similar import discovery logic to that of 'use' suggestions.
2634 fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> {
2635 let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default();
2637 if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
2638 // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
2639 // wrapper can be used to suppress this query, in exchange for full paths being formatted.
2640 tcx.sess.delay_good_path_bug("trimmed_def_paths constructed");
2643 let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
2644 &mut FxHashMap::default();
2646 for symbol_set in tcx.resolutions(()).glob_map.values() {
2647 for symbol in symbol_set {
2648 unique_symbols_rev.insert((Namespace::TypeNS, *symbol), None);
2649 unique_symbols_rev.insert((Namespace::ValueNS, *symbol), None);
2650 unique_symbols_rev.insert((Namespace::MacroNS, *symbol), None);
2654 for_each_def(tcx, |ident, ns, def_id| {
2655 use std::collections::hash_map::Entry::{Occupied, Vacant};
2657 match unique_symbols_rev.entry((ns, ident.name)) {
2658 Occupied(mut v) => match v.get() {
2661 if *existing != def_id {
2667 v.insert(Some(def_id));
2672 for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
2673 use std::collections::hash_map::Entry::{Occupied, Vacant};
2675 if let Some(def_id) = opt_def_id {
2676 match map.entry(def_id) {
2677 Occupied(mut v) => {
2678 // A single DefId can be known under multiple names (e.g.,
2679 // with a `pub use ... as ...;`). We need to ensure that the
2680 // name placed in this map is chosen deterministically, so
2681 // if we find multiple names (`symbol`) resolving to the
2682 // same `def_id`, we prefer the lexicographically smallest
2685 // Any stable ordering would be fine here though.
2686 if *v.get() != symbol {
2687 if v.get().as_str() > symbol.as_str() {
2702 pub fn provide(providers: &mut ty::query::Providers) {
2703 *providers = ty::query::Providers { trimmed_def_paths, ..*providers };
2707 pub struct OpaqueFnEntry<'tcx> {
2708 // The trait ref is already stored as a key, so just track if we have it as a real predicate
2710 fn_mut_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
2711 fn_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
2712 return_ty: Option<ty::Binder<'tcx, Ty<'tcx>>>,