1 use crate::mir::interpret::{AllocRange, GlobalAlloc, Pointer, Provenance, Scalar};
2 use crate::query::IntoQueryParam;
3 use crate::query::Providers;
4 use crate::ty::{
5 self, ConstInt, ParamConst, ScalarInt, Term, TermKind, Ty, TyCtxt, TypeFoldable,
6 TypeSuperFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
7 };
8 use crate::ty::{GenericArg, GenericArgKind};
9 use rustc_apfloat::ieee::{Double, Single};
10 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
11 use rustc_data_structures::sso::SsoHashSet;
12 use rustc_hir as hir;
13 use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
14 use rustc_hir::def_id::{DefId, DefIdSet, CRATE_DEF_ID, LOCAL_CRATE};
15 use rustc_hir::definitions::{DefKey, DefPathData, DefPathDataName, DisambiguatedDefPathData};
16 use rustc_hir::LangItem;
17 use rustc_session::config::TrimmedDefPaths;
18 use rustc_session::cstore::{ExternCrate, ExternCrateSource};
19 use rustc_session::Limit;
20 use rustc_span::symbol::{kw, Ident, Symbol};
21 use rustc_span::FileNameDisplayPreference;
22 use rustc_target::abi::Size;
23 use rustc_target::spec::abi::Abi;
24 use smallvec::SmallVec;
25
26 use std::cell::Cell;
27 use std::collections::BTreeMap;
28 use std::fmt::{self, Write as _};
29 use std::iter;
30 use std::ops::{ControlFlow, Deref, DerefMut};
31
32 // `pretty` is a separate module only for organization.
33 use super::*;
34
35 macro_rules! p {
36 (@$lit:literal) => {
37 write!(scoped_cx!(), $lit)?
38 };
39 (@write($($data:expr),+)) => {
40 write!(scoped_cx!(), $($data),+)?
41 };
42 (@print($x:expr)) => {
43 scoped_cx!() = $x.print(scoped_cx!())?
44 };
45 (@$method:ident($($arg:expr),*)) => {
46 scoped_cx!() = scoped_cx!().$method($($arg),*)?
47 };
48 ($($elem:tt $(($($args:tt)*))?),+) => {{
49 $(p!(@ $elem $(($($args)*))?);)+
50 }};
51 }
52 macro_rules! define_scoped_cx {
53 ($cx:ident) => {
54 #[allow(unused_macros)]
55 macro_rules! scoped_cx {
56 () => {
57 $cx
58 };
59 }
60 };
61 }
62
63 thread_local! {
64 static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) };
65 static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) };
66 static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
67 static FORCE_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
68 static NO_QUERIES: Cell<bool> = const { Cell::new(false) };
69 static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) };
70 }
71
72 macro_rules! define_helper {
73 ($($(#[$a:meta])* fn $name:ident($helper:ident, $tl:ident);)+) => {
74 $(
75 #[must_use]
76 pub struct $helper(bool);
77
78 impl $helper {
79 pub fn new() -> $helper {
80 $helper($tl.with(|c| c.replace(true)))
81 }
82 }
83
84 $(#[$a])*
85 pub macro $name($e:expr) {
86 {
87 let _guard = $helper::new();
88 $e
89 }
90 }
91
92 impl Drop for $helper {
93 fn drop(&mut self) {
94 $tl.with(|c| c.set(self.0))
95 }
96 }
97
98 pub fn $name() -> bool {
99 $tl.with(|c| c.get())
100 }
101 )+
102 }
103 }
104
105 define_helper!(
106 /// Avoids running any queries during any prints that occur
107 /// during the closure. This may alter the appearance of some
108 /// types (e.g. forcing verbose printing for opaque types).
109 /// This method is used during some queries (e.g. `explicit_item_bounds`
110 /// for opaque types), to ensure that any debug printing that
111 /// occurs during the query computation does not end up recursively
112 /// calling the same query.
113 fn with_no_queries(NoQueriesGuard, NO_QUERIES);
114 /// Force us to name impls with just the filename/line number. We
115 /// normally try to use types. But at some points, notably while printing
116 /// cycle errors, this can result in extra or suboptimal error output,
117 /// so this variable disables that check.
118 fn with_forced_impl_filename_line(ForcedImplGuard, FORCE_IMPL_FILENAME_LINE);
119 /// Adds the `crate::` prefix to paths where appropriate.
120 fn with_crate_prefix(CratePrefixGuard, SHOULD_PREFIX_WITH_CRATE);
121 /// Prevent path trimming if it is turned on. Path trimming affects `Display` impl
122 /// of various rustc types, for example `std::vec::Vec` would be trimmed to `Vec`,
123 /// if no other `Vec` is found.
124 fn with_no_trimmed_paths(NoTrimmedGuard, NO_TRIMMED_PATH);
125 fn with_forced_trimmed_paths(ForceTrimmedGuard, FORCE_TRIMMED_PATH);
126 /// Prevent selection of visible paths. `Display` impl of DefId will prefer
127 /// visible (public) reexports of types as paths.
128 fn with_no_visible_paths(NoVisibleGuard, NO_VISIBLE_PATH);
129 );
130
131 /// The "region highlights" are used to control region printing during
132 /// specific error messages. When a "region highlight" is enabled, it
133 /// gives an alternate way to print specific regions. For now, we
134 /// always print those regions using a number, so something like "`'0`".
135 ///
136 /// Regions not selected by the region highlight mode are presently
137 /// unaffected.
138 #[derive(Copy, Clone)]
139 pub struct RegionHighlightMode<'tcx> {
140 tcx: TyCtxt<'tcx>,
141
142 /// If enabled, when we see the selected region, use "`'N`"
143 /// instead of the ordinary behavior.
144 highlight_regions: [Option<(ty::Region<'tcx>, usize)>; 3],
145
146 /// If enabled, when printing a "free region" that originated from
147 /// the given `ty::BoundRegionKind`, print it as "`'1`". Free regions that would ordinarily
148 /// have names print as normal.
149 ///
150 /// This is used when you have a signature like `fn foo(x: &u32,
151 /// y: &'a u32)` and we want to give a name to the region of the
152 /// reference `x`.
153 highlight_bound_region: Option<(ty::BoundRegionKind, usize)>,
154 }
155
156 impl<'tcx> RegionHighlightMode<'tcx> {
new(tcx: TyCtxt<'tcx>) -> Self157 pub fn new(tcx: TyCtxt<'tcx>) -> Self {
158 Self {
159 tcx,
160 highlight_regions: Default::default(),
161 highlight_bound_region: Default::default(),
162 }
163 }
164
165 /// If `region` and `number` are both `Some`, invokes
166 /// `highlighting_region`.
maybe_highlighting_region( &mut self, region: Option<ty::Region<'tcx>>, number: Option<usize>, )167 pub fn maybe_highlighting_region(
168 &mut self,
169 region: Option<ty::Region<'tcx>>,
170 number: Option<usize>,
171 ) {
172 if let Some(k) = region {
173 if let Some(n) = number {
174 self.highlighting_region(k, n);
175 }
176 }
177 }
178
179 /// Highlights the region inference variable `vid` as `'N`.
highlighting_region(&mut self, region: ty::Region<'tcx>, number: usize)180 pub fn highlighting_region(&mut self, region: ty::Region<'tcx>, number: usize) {
181 let num_slots = self.highlight_regions.len();
182 let first_avail_slot =
183 self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
184 bug!("can only highlight {} placeholders at a time", num_slots,)
185 });
186 *first_avail_slot = Some((region, number));
187 }
188
189 /// Convenience wrapper for `highlighting_region`.
highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize)190 pub fn highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize) {
191 self.highlighting_region(ty::Region::new_var(self.tcx, vid), number)
192 }
193
194 /// Returns `Some(n)` with the number to use for the given region, if any.
region_highlighted(&self, region: ty::Region<'tcx>) -> Option<usize>195 fn region_highlighted(&self, region: ty::Region<'tcx>) -> Option<usize> {
196 self.highlight_regions.iter().find_map(|h| match h {
197 Some((r, n)) if *r == region => Some(*n),
198 _ => None,
199 })
200 }
201
202 /// Highlight the given bound region.
203 /// We can only highlight one bound region at a time. See
204 /// the field `highlight_bound_region` for more detailed notes.
highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize)205 pub fn highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize) {
206 assert!(self.highlight_bound_region.is_none());
207 self.highlight_bound_region = Some((br, number));
208 }
209 }
210
211 /// Trait for printers that pretty-print using `fmt::Write` to the printer.
212 pub trait PrettyPrinter<'tcx>:
213 Printer<
214 'tcx,
215 Error = fmt::Error,
216 Path = Self,
217 Region = Self,
218 Type = Self,
219 DynExistential = Self,
220 Const = Self,
221 > + fmt::Write
222 {
223 /// Like `print_def_path` but for value paths.
print_value_path( self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>224 fn print_value_path(
225 self,
226 def_id: DefId,
227 substs: &'tcx [GenericArg<'tcx>],
228 ) -> Result<Self::Path, Self::Error> {
229 self.print_def_path(def_id, substs)
230 }
231
in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,232 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
233 where
234 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
235 {
236 value.as_ref().skip_binder().print(self)
237 }
238
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<TyCtxt<'tcx>>,239 fn wrap_binder<T, F: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
240 self,
241 value: &ty::Binder<'tcx, T>,
242 f: F,
243 ) -> Result<Self, Self::Error>
244 where
245 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
246 {
247 f(value.as_ref().skip_binder(), self)
248 }
249
250 /// Prints comma-separated elements.
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>,251 fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
252 where
253 T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
254 {
255 if let Some(first) = elems.next() {
256 self = first.print(self)?;
257 for elem in elems {
258 self.write_str(", ")?;
259 self = elem.print(self)?;
260 }
261 }
262 Ok(self)
263 }
264
265 /// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
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>266 fn typed_value(
267 mut self,
268 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
269 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
270 conversion: &str,
271 ) -> Result<Self::Const, Self::Error> {
272 self.write_str("{")?;
273 self = f(self)?;
274 self.write_str(conversion)?;
275 self = t(self)?;
276 self.write_str("}")?;
277 Ok(self)
278 }
279
280 /// Prints `<...>` around what `f` prints.
generic_delimiters( self, f: impl FnOnce(Self) -> Result<Self, Self::Error>, ) -> Result<Self, Self::Error>281 fn generic_delimiters(
282 self,
283 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
284 ) -> Result<Self, Self::Error>;
285
286 /// Returns `true` if the region should be printed in
287 /// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
288 /// This is typically the case for all non-`'_` regions.
should_print_region(&self, region: ty::Region<'tcx>) -> bool289 fn should_print_region(&self, region: ty::Region<'tcx>) -> bool;
290
reset_type_limit(&mut self)291 fn reset_type_limit(&mut self) {}
292
293 // Defaults (should not be overridden):
294
295 /// If possible, this returns a global path resolving to `def_id` that is visible
296 /// from at least one local module, and returns `true`. If the crate defining `def_id` is
297 /// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error>298 fn try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
299 if NO_VISIBLE_PATH.with(|flag| flag.get()) {
300 return Ok((self, false));
301 }
302
303 let mut callers = Vec::new();
304 self.try_print_visible_def_path_recur(def_id, &mut callers)
305 }
306
307 // Given a `DefId`, produce a short name. For types and traits, it prints *only* its name,
308 // For associated items on traits it prints out the trait's name and the associated item's name.
309 // For enum variants, if they have an unique name, then we only print the name, otherwise we
310 // print the enum name and the variant name. Otherwise, we do not print anything and let the
311 // caller use the `print_def_path` fallback.
force_print_trimmed_def_path( mut self, def_id: DefId, ) -> Result<(Self::Path, bool), Self::Error>312 fn force_print_trimmed_def_path(
313 mut self,
314 def_id: DefId,
315 ) -> Result<(Self::Path, bool), Self::Error> {
316 let key = self.tcx().def_key(def_id);
317 let visible_parent_map = self.tcx().visible_parent_map(());
318 let kind = self.tcx().def_kind(def_id);
319
320 let get_local_name = |this: &Self, name, def_id, key: DefKey| {
321 if let Some(visible_parent) = visible_parent_map.get(&def_id)
322 && let actual_parent = this.tcx().opt_parent(def_id)
323 && let DefPathData::TypeNs(_) = key.disambiguated_data.data
324 && Some(*visible_parent) != actual_parent
325 {
326 this
327 .tcx()
328 .module_children(visible_parent)
329 .iter()
330 .filter(|child| child.res.opt_def_id() == Some(def_id))
331 .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
332 .map(|child| child.ident.name)
333 .unwrap_or(name)
334 } else {
335 name
336 }
337 };
338 if let DefKind::Variant = kind
339 && let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id)
340 {
341 // If `Assoc` is unique, we don't want to talk about `Trait::Assoc`.
342 self.write_str(get_local_name(&self, *symbol, def_id, key).as_str())?;
343 return Ok((self, true));
344 }
345 if let Some(symbol) = key.get_opt_name() {
346 if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = kind
347 && let Some(parent) = self.tcx().opt_parent(def_id)
348 && let parent_key = self.tcx().def_key(parent)
349 && let Some(symbol) = parent_key.get_opt_name()
350 {
351 // Trait
352 self.write_str(get_local_name(&self, symbol, parent, parent_key).as_str())?;
353 self.write_str("::")?;
354 } else if let DefKind::Variant = kind
355 && let Some(parent) = self.tcx().opt_parent(def_id)
356 && let parent_key = self.tcx().def_key(parent)
357 && let Some(symbol) = parent_key.get_opt_name()
358 {
359 // Enum
360
361 // For associated items and variants, we want the "full" path, namely, include
362 // the parent type in the path. For example, `Iterator::Item`.
363 self.write_str(get_local_name(&self, symbol, parent, parent_key).as_str())?;
364 self.write_str("::")?;
365 } else if let DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Trait
366 | DefKind::TyAlias | DefKind::Fn | DefKind::Const | DefKind::Static(_) = kind
367 {
368 } else {
369 // If not covered above, like for example items out of `impl` blocks, fallback.
370 return Ok((self, false));
371 }
372 self.write_str(get_local_name(&self, symbol, def_id, key).as_str())?;
373 return Ok((self, true));
374 }
375 Ok((self, false))
376 }
377
378 /// Try to see if this path can be trimmed to a unique symbol name.
try_print_trimmed_def_path( mut self, def_id: DefId, ) -> Result<(Self::Path, bool), Self::Error>379 fn try_print_trimmed_def_path(
380 mut self,
381 def_id: DefId,
382 ) -> Result<(Self::Path, bool), Self::Error> {
383 if FORCE_TRIMMED_PATH.with(|flag| flag.get()) {
384 let (s, trimmed) = self.force_print_trimmed_def_path(def_id)?;
385 if trimmed {
386 return Ok((s, true));
387 }
388 self = s;
389 }
390 if !self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
391 || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never)
392 || NO_TRIMMED_PATH.with(|flag| flag.get())
393 || SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get())
394 {
395 return Ok((self, false));
396 }
397
398 match self.tcx().trimmed_def_paths(()).get(&def_id) {
399 None => Ok((self, false)),
400 Some(symbol) => {
401 write!(self, "{}", Ident::with_dummy_span(*symbol))?;
402 Ok((self, true))
403 }
404 }
405 }
406
407 /// Does the work of `try_print_visible_def_path`, building the
408 /// full definition path recursively before attempting to
409 /// post-process it into the valid and visible version that
410 /// accounts for re-exports.
411 ///
412 /// This method should only be called by itself or
413 /// `try_print_visible_def_path`.
414 ///
415 /// `callers` is a chain of visible_parent's leading to `def_id`,
416 /// to support cycle detection during recursion.
417 ///
418 /// This method returns false if we can't print the visible path, so
419 /// `print_def_path` can fall back on the item's real definition path.
try_print_visible_def_path_recur( mut self, def_id: DefId, callers: &mut Vec<DefId>, ) -> Result<(Self, bool), Self::Error>420 fn try_print_visible_def_path_recur(
421 mut self,
422 def_id: DefId,
423 callers: &mut Vec<DefId>,
424 ) -> Result<(Self, bool), Self::Error> {
425 define_scoped_cx!(self);
426
427 debug!("try_print_visible_def_path: def_id={:?}", def_id);
428
429 // If `def_id` is a direct or injected extern crate, return the
430 // path to the crate followed by the path to the item within the crate.
431 if let Some(cnum) = def_id.as_crate_root() {
432 if cnum == LOCAL_CRATE {
433 return Ok((self.path_crate(cnum)?, true));
434 }
435
436 // In local mode, when we encounter a crate other than
437 // LOCAL_CRATE, execution proceeds in one of two ways:
438 //
439 // 1. For a direct dependency, where user added an
440 // `extern crate` manually, we put the `extern
441 // crate` as the parent. So you wind up with
442 // something relative to the current crate.
443 // 2. For an extern inferred from a path or an indirect crate,
444 // where there is no explicit `extern crate`, we just prepend
445 // the crate name.
446 match self.tcx().extern_crate(def_id) {
447 Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
448 (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
449 // NOTE(eddyb) the only reason `span` might be dummy,
450 // that we're aware of, is that it's the `std`/`core`
451 // `extern crate` injected by default.
452 // FIXME(eddyb) find something better to key this on,
453 // or avoid ending up with `ExternCrateSource::Extern`,
454 // for the injected `std`/`core`.
455 if span.is_dummy() {
456 return Ok((self.path_crate(cnum)?, true));
457 }
458
459 // Disable `try_print_trimmed_def_path` behavior within
460 // the `print_def_path` call, to avoid infinite recursion
461 // in cases where the `extern crate foo` has non-trivial
462 // parents, e.g. it's nested in `impl foo::Trait for Bar`
463 // (see also issues #55779 and #87932).
464 self = with_no_visible_paths!(self.print_def_path(def_id, &[])?);
465
466 return Ok((self, true));
467 }
468 (ExternCrateSource::Path, LOCAL_CRATE) => {
469 return Ok((self.path_crate(cnum)?, true));
470 }
471 _ => {}
472 },
473 None => {
474 return Ok((self.path_crate(cnum)?, true));
475 }
476 }
477 }
478
479 if def_id.is_local() {
480 return Ok((self, false));
481 }
482
483 let visible_parent_map = self.tcx().visible_parent_map(());
484
485 let mut cur_def_key = self.tcx().def_key(def_id);
486 debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
487
488 // For a constructor, we want the name of its parent rather than <unnamed>.
489 if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
490 let parent = DefId {
491 krate: def_id.krate,
492 index: cur_def_key
493 .parent
494 .expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
495 };
496
497 cur_def_key = self.tcx().def_key(parent);
498 }
499
500 let Some(visible_parent) = visible_parent_map.get(&def_id).cloned() else {
501 return Ok((self, false));
502 };
503
504 let actual_parent = self.tcx().opt_parent(def_id);
505 debug!(
506 "try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
507 visible_parent, actual_parent,
508 );
509
510 let mut data = cur_def_key.disambiguated_data.data;
511 debug!(
512 "try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
513 data, visible_parent, actual_parent,
514 );
515
516 match data {
517 // In order to output a path that could actually be imported (valid and visible),
518 // we need to handle re-exports correctly.
519 //
520 // For example, take `std::os::unix::process::CommandExt`, this trait is actually
521 // defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
522 //
523 // `std::os::unix` reexports the contents of `std::sys::unix::ext`. `std::sys` is
524 // private so the "true" path to `CommandExt` isn't accessible.
525 //
526 // In this case, the `visible_parent_map` will look something like this:
527 //
528 // (child) -> (parent)
529 // `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
530 // `std::sys::unix::ext::process` -> `std::sys::unix::ext`
531 // `std::sys::unix::ext` -> `std::os`
532 //
533 // This is correct, as the visible parent of `std::sys::unix::ext` is in fact
534 // `std::os`.
535 //
536 // When printing the path to `CommandExt` and looking at the `cur_def_key` that
537 // corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
538 // to the parent - resulting in a mangled path like
539 // `std::os::ext::process::CommandExt`.
540 //
541 // Instead, we must detect that there was a re-export and instead print `unix`
542 // (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
543 // do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
544 // the visible parent (`std::os`). If these do not match, then we iterate over
545 // the children of the visible parent (as was done when computing
546 // `visible_parent_map`), looking for the specific child we currently have and then
547 // have access to the re-exported name.
548 DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
549 // Item might be re-exported several times, but filter for the one
550 // that's public and whose identifier isn't `_`.
551 let reexport = self
552 .tcx()
553 .module_children(visible_parent)
554 .iter()
555 .filter(|child| child.res.opt_def_id() == Some(def_id))
556 .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
557 .map(|child| child.ident.name);
558
559 if let Some(new_name) = reexport {
560 *name = new_name;
561 } else {
562 // There is no name that is public and isn't `_`, so bail.
563 return Ok((self, false));
564 }
565 }
566 // Re-exported `extern crate` (#43189).
567 DefPathData::CrateRoot => {
568 data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
569 }
570 _ => {}
571 }
572 debug!("try_print_visible_def_path: data={:?}", data);
573
574 if callers.contains(&visible_parent) {
575 return Ok((self, false));
576 }
577 callers.push(visible_parent);
578 // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
579 // knowing ahead of time whether the entire path will succeed or not.
580 // To support printers that do not implement `PrettyPrinter`, a `Vec` or
581 // linked list on the stack would need to be built, before any printing.
582 match self.try_print_visible_def_path_recur(visible_parent, callers)? {
583 (cx, false) => return Ok((cx, false)),
584 (cx, true) => self = cx,
585 }
586 callers.pop();
587
588 Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
589 }
590
pretty_path_qualified( self, self_ty: Ty<'tcx>, trait_ref: Option<ty::TraitRef<'tcx>>, ) -> Result<Self::Path, Self::Error>591 fn pretty_path_qualified(
592 self,
593 self_ty: Ty<'tcx>,
594 trait_ref: Option<ty::TraitRef<'tcx>>,
595 ) -> Result<Self::Path, Self::Error> {
596 if trait_ref.is_none() {
597 // Inherent impls. Try to print `Foo::bar` for an inherent
598 // impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
599 // anything other than a simple path.
600 match self_ty.kind() {
601 ty::Adt(..)
602 | ty::Foreign(_)
603 | ty::Bool
604 | ty::Char
605 | ty::Str
606 | ty::Int(_)
607 | ty::Uint(_)
608 | ty::Float(_) => {
609 return self_ty.print(self);
610 }
611
612 _ => {}
613 }
614 }
615
616 self.generic_delimiters(|mut cx| {
617 define_scoped_cx!(cx);
618
619 p!(print(self_ty));
620 if let Some(trait_ref) = trait_ref {
621 p!(" as ", print(trait_ref.print_only_trait_path()));
622 }
623 Ok(cx)
624 })
625 }
626
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>627 fn pretty_path_append_impl(
628 mut self,
629 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
630 self_ty: Ty<'tcx>,
631 trait_ref: Option<ty::TraitRef<'tcx>>,
632 ) -> Result<Self::Path, Self::Error> {
633 self = print_prefix(self)?;
634
635 self.generic_delimiters(|mut cx| {
636 define_scoped_cx!(cx);
637
638 p!("impl ");
639 if let Some(trait_ref) = trait_ref {
640 p!(print(trait_ref.print_only_trait_path()), " for ");
641 }
642 p!(print(self_ty));
643
644 Ok(cx)
645 })
646 }
647
pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error>648 fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
649 define_scoped_cx!(self);
650
651 match *ty.kind() {
652 ty::Bool => p!("bool"),
653 ty::Char => p!("char"),
654 ty::Int(t) => p!(write("{}", t.name_str())),
655 ty::Uint(t) => p!(write("{}", t.name_str())),
656 ty::Float(t) => p!(write("{}", t.name_str())),
657 ty::RawPtr(ref tm) => {
658 p!(write(
659 "*{} ",
660 match tm.mutbl {
661 hir::Mutability::Mut => "mut",
662 hir::Mutability::Not => "const",
663 }
664 ));
665 p!(print(tm.ty))
666 }
667 ty::Ref(r, ty, mutbl) => {
668 p!("&");
669 if self.should_print_region(r) {
670 p!(print(r), " ");
671 }
672 p!(print(ty::TypeAndMut { ty, mutbl }))
673 }
674 ty::Never => p!("!"),
675 ty::Tuple(ref tys) => {
676 p!("(", comma_sep(tys.iter()));
677 if tys.len() == 1 {
678 p!(",");
679 }
680 p!(")")
681 }
682 ty::FnDef(def_id, substs) => {
683 if with_no_queries() {
684 p!(print_def_path(def_id, substs));
685 } else {
686 let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
687 p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
688 }
689 }
690 ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
691 ty::Infer(infer_ty) => {
692 if self.should_print_verbose() {
693 p!(write("{:?}", ty.kind()));
694 return Ok(self);
695 }
696
697 if let ty::TyVar(ty_vid) = infer_ty {
698 if let Some(name) = self.ty_infer_name(ty_vid) {
699 p!(write("{}", name))
700 } else {
701 p!(write("{}", infer_ty))
702 }
703 } else {
704 p!(write("{}", infer_ty))
705 }
706 }
707 ty::Error(_) => p!("{{type error}}"),
708 ty::Param(ref param_ty) => p!(print(param_ty)),
709 ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
710 ty::BoundTyKind::Anon => {
711 rustc_type_ir::debug_bound_var(&mut self, debruijn, bound_ty.var)?
712 }
713 ty::BoundTyKind::Param(_, s) => match self.should_print_verbose() {
714 true => p!(write("{:?}", ty.kind())),
715 false => p!(write("{s}")),
716 },
717 },
718 ty::Adt(def, substs) => {
719 p!(print_def_path(def.did(), substs));
720 }
721 ty::Dynamic(data, r, repr) => {
722 let print_r = self.should_print_region(r);
723 if print_r {
724 p!("(");
725 }
726 match repr {
727 ty::Dyn => p!("dyn "),
728 ty::DynStar => p!("dyn* "),
729 }
730 p!(print(data));
731 if print_r {
732 p!(" + ", print(r), ")");
733 }
734 }
735 ty::Foreign(def_id) => {
736 p!(print_def_path(def_id, &[]));
737 }
738 ty::Alias(ty::Projection | ty::Inherent | ty::Weak, ref data) => {
739 if !(self.should_print_verbose() || with_no_queries())
740 && self.tcx().is_impl_trait_in_trait(data.def_id)
741 {
742 return self.pretty_print_opaque_impl_type(data.def_id, data.substs);
743 } else {
744 p!(print(data))
745 }
746 }
747 ty::Placeholder(placeholder) => match placeholder.bound.kind {
748 ty::BoundTyKind::Anon => p!(write("{placeholder:?}")),
749 ty::BoundTyKind::Param(_, name) => match self.should_print_verbose() {
750 true => p!(write("{:?}", ty.kind())),
751 false => p!(write("{name}")),
752 },
753 },
754 ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => {
755 // We use verbose printing in 'NO_QUERIES' mode, to
756 // avoid needing to call `predicates_of`. This should
757 // only affect certain debug messages (e.g. messages printed
758 // from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
759 // and should have no effect on any compiler output.
760 if self.should_print_verbose() {
761 // FIXME(eddyb) print this with `print_def_path`.
762 p!(write("Opaque({:?}, {:?})", def_id, substs));
763 return Ok(self);
764 }
765
766 let parent = self.tcx().parent(def_id);
767 match self.tcx().def_kind(parent) {
768 DefKind::TyAlias | DefKind::AssocTy => {
769 // NOTE: I know we should check for NO_QUERIES here, but it's alright.
770 // `type_of` on a type alias or assoc type should never cause a cycle.
771 if let ty::Alias(ty::Opaque, ty::AliasTy { def_id: d, .. }) =
772 *self.tcx().type_of(parent).subst_identity().kind()
773 {
774 if d == def_id {
775 // If the type alias directly starts with the `impl` of the
776 // opaque type we're printing, then skip the `::{opaque#1}`.
777 p!(print_def_path(parent, substs));
778 return Ok(self);
779 }
780 }
781 // Complex opaque type, e.g. `type Foo = (i32, impl Debug);`
782 p!(print_def_path(def_id, substs));
783 return Ok(self);
784 }
785 _ => {
786 if with_no_queries() {
787 p!(print_def_path(def_id, &[]));
788 return Ok(self);
789 } else {
790 return self.pretty_print_opaque_impl_type(def_id, substs);
791 }
792 }
793 }
794 }
795 ty::Str => p!("str"),
796 ty::Generator(did, substs, movability) => {
797 p!(write("["));
798 let generator_kind = self.tcx().generator_kind(did).unwrap();
799 let should_print_movability =
800 self.should_print_verbose() || generator_kind == hir::GeneratorKind::Gen;
801
802 if should_print_movability {
803 match movability {
804 hir::Movability::Movable => {}
805 hir::Movability::Static => p!("static "),
806 }
807 }
808
809 if !self.should_print_verbose() {
810 p!(write("{}", generator_kind));
811 // FIXME(eddyb) should use `def_span`.
812 if let Some(did) = did.as_local() {
813 let span = self.tcx().def_span(did);
814 p!(write(
815 "@{}",
816 // This may end up in stderr diagnostics but it may also be emitted
817 // into MIR. Hence we use the remapped path if available
818 self.tcx().sess.source_map().span_to_embeddable_string(span)
819 ));
820 } else {
821 p!(write("@"), print_def_path(did, substs));
822 }
823 } else {
824 p!(print_def_path(did, substs));
825 p!(" upvar_tys=(");
826 if !substs.as_generator().is_valid() {
827 p!("unavailable");
828 } else {
829 self = self.comma_sep(substs.as_generator().upvar_tys())?;
830 }
831 p!(")");
832
833 if substs.as_generator().is_valid() {
834 p!(" ", print(substs.as_generator().witness()));
835 }
836 }
837
838 p!("]")
839 }
840 ty::GeneratorWitness(types) => {
841 p!(in_binder(&types));
842 }
843 ty::GeneratorWitnessMIR(did, substs) => {
844 p!(write("["));
845 if !self.tcx().sess.verbose() {
846 p!("generator witness");
847 // FIXME(eddyb) should use `def_span`.
848 if let Some(did) = did.as_local() {
849 let span = self.tcx().def_span(did);
850 p!(write(
851 "@{}",
852 // This may end up in stderr diagnostics but it may also be emitted
853 // into MIR. Hence we use the remapped path if available
854 self.tcx().sess.source_map().span_to_embeddable_string(span)
855 ));
856 } else {
857 p!(write("@"), print_def_path(did, substs));
858 }
859 } else {
860 p!(print_def_path(did, substs));
861 }
862
863 p!("]")
864 }
865 ty::Closure(did, substs) => {
866 p!(write("["));
867 if !self.should_print_verbose() {
868 p!(write("closure"));
869 // FIXME(eddyb) should use `def_span`.
870 if let Some(did) = did.as_local() {
871 if self.tcx().sess.opts.unstable_opts.span_free_formats {
872 p!("@", print_def_path(did.to_def_id(), substs));
873 } else {
874 let span = self.tcx().def_span(did);
875 let preference = if FORCE_TRIMMED_PATH.with(|flag| flag.get()) {
876 FileNameDisplayPreference::Short
877 } else {
878 FileNameDisplayPreference::Remapped
879 };
880 p!(write(
881 "@{}",
882 // This may end up in stderr diagnostics but it may also be emitted
883 // into MIR. Hence we use the remapped path if available
884 self.tcx().sess.source_map().span_to_string(span, preference)
885 ));
886 }
887 } else {
888 p!(write("@"), print_def_path(did, substs));
889 }
890 } else {
891 p!(print_def_path(did, substs));
892 if !substs.as_closure().is_valid() {
893 p!(" closure_substs=(unavailable)");
894 p!(write(" substs={:?}", substs));
895 } else {
896 p!(" closure_kind_ty=", print(substs.as_closure().kind_ty()));
897 p!(
898 " closure_sig_as_fn_ptr_ty=",
899 print(substs.as_closure().sig_as_fn_ptr_ty())
900 );
901 p!(" upvar_tys=(");
902 self = self.comma_sep(substs.as_closure().upvar_tys())?;
903 p!(")");
904 }
905 }
906 p!("]");
907 }
908 ty::Array(ty, sz) => p!("[", print(ty), "; ", print(sz), "]"),
909 ty::Slice(ty) => p!("[", print(ty), "]"),
910 }
911
912 Ok(self)
913 }
914
pretty_print_opaque_impl_type( mut self, def_id: DefId, substs: &'tcx ty::List<ty::GenericArg<'tcx>>, ) -> Result<Self::Type, Self::Error>915 fn pretty_print_opaque_impl_type(
916 mut self,
917 def_id: DefId,
918 substs: &'tcx ty::List<ty::GenericArg<'tcx>>,
919 ) -> Result<Self::Type, Self::Error> {
920 let tcx = self.tcx();
921
922 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
923 // by looking up the projections associated with the def_id.
924 let bounds = tcx.explicit_item_bounds(def_id);
925
926 let mut traits = FxIndexMap::default();
927 let mut fn_traits = FxIndexMap::default();
928 let mut is_sized = false;
929 let mut lifetimes = SmallVec::<[ty::Region<'tcx>; 1]>::new();
930
931 for (predicate, _) in bounds.subst_iter_copied(tcx, substs) {
932 let bound_predicate = predicate.kind();
933
934 match bound_predicate.skip_binder() {
935 ty::ClauseKind::Trait(pred) => {
936 let trait_ref = bound_predicate.rebind(pred.trait_ref);
937
938 // Don't print + Sized, but rather + ?Sized if absent.
939 if Some(trait_ref.def_id()) == tcx.lang_items().sized_trait() {
940 is_sized = true;
941 continue;
942 }
943
944 self.insert_trait_and_projection(trait_ref, None, &mut traits, &mut fn_traits);
945 }
946 ty::ClauseKind::Projection(pred) => {
947 let proj_ref = bound_predicate.rebind(pred);
948 let trait_ref = proj_ref.required_poly_trait_ref(tcx);
949
950 // Projection type entry -- the def-id for naming, and the ty.
951 let proj_ty = (proj_ref.projection_def_id(), proj_ref.term());
952
953 self.insert_trait_and_projection(
954 trait_ref,
955 Some(proj_ty),
956 &mut traits,
957 &mut fn_traits,
958 );
959 }
960 ty::ClauseKind::TypeOutlives(outlives) => {
961 lifetimes.push(outlives.1);
962 }
963 _ => {}
964 }
965 }
966
967 write!(self, "impl ")?;
968
969 let mut first = true;
970 // Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
971 let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !is_sized;
972
973 for (fn_once_trait_ref, entry) in fn_traits {
974 write!(self, "{}", if first { "" } else { " + " })?;
975 write!(self, "{}", if paren_needed { "(" } else { "" })?;
976
977 self = self.wrap_binder(&fn_once_trait_ref, |trait_ref, mut cx| {
978 define_scoped_cx!(cx);
979 // Get the (single) generic ty (the args) of this FnOnce trait ref.
980 let generics = tcx.generics_of(trait_ref.def_id);
981 let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
982
983 match (entry.return_ty, args[0].expect_ty()) {
984 // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
985 // a return type.
986 (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
987 let name = if entry.fn_trait_ref.is_some() {
988 "Fn"
989 } else if entry.fn_mut_trait_ref.is_some() {
990 "FnMut"
991 } else {
992 "FnOnce"
993 };
994
995 p!(write("{}(", name));
996
997 for (idx, ty) in arg_tys.tuple_fields().iter().enumerate() {
998 if idx > 0 {
999 p!(", ");
1000 }
1001 p!(print(ty));
1002 }
1003
1004 p!(")");
1005 if let Some(ty) = return_ty.skip_binder().ty() {
1006 if !ty.is_unit() {
1007 p!(" -> ", print(return_ty));
1008 }
1009 }
1010 p!(write("{}", if paren_needed { ")" } else { "" }));
1011
1012 first = false;
1013 }
1014 // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
1015 // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
1016 _ => {
1017 if entry.has_fn_once {
1018 traits.entry(fn_once_trait_ref).or_default().extend(
1019 // Group the return ty with its def id, if we had one.
1020 entry
1021 .return_ty
1022 .map(|ty| (tcx.require_lang_item(LangItem::FnOnce, None), ty)),
1023 );
1024 }
1025 if let Some(trait_ref) = entry.fn_mut_trait_ref {
1026 traits.entry(trait_ref).or_default();
1027 }
1028 if let Some(trait_ref) = entry.fn_trait_ref {
1029 traits.entry(trait_ref).or_default();
1030 }
1031 }
1032 }
1033
1034 Ok(cx)
1035 })?;
1036 }
1037
1038 // Print the rest of the trait types (that aren't Fn* family of traits)
1039 for (trait_ref, assoc_items) in traits {
1040 write!(self, "{}", if first { "" } else { " + " })?;
1041
1042 self = self.wrap_binder(&trait_ref, |trait_ref, mut cx| {
1043 define_scoped_cx!(cx);
1044 p!(print(trait_ref.print_only_trait_name()));
1045
1046 let generics = tcx.generics_of(trait_ref.def_id);
1047 let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
1048
1049 if !args.is_empty() || !assoc_items.is_empty() {
1050 let mut first = true;
1051
1052 for ty in args {
1053 if first {
1054 p!("<");
1055 first = false;
1056 } else {
1057 p!(", ");
1058 }
1059 p!(print(ty));
1060 }
1061
1062 for (assoc_item_def_id, term) in assoc_items {
1063 // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks,
1064 // unless we can find out what generator return type it comes from.
1065 let term = if let Some(ty) = term.skip_binder().ty()
1066 && let ty::Alias(ty::Projection, proj) = ty.kind()
1067 && let Some(assoc) = tcx.opt_associated_item(proj.def_id)
1068 && assoc.trait_container(tcx) == tcx.lang_items().gen_trait()
1069 && assoc.name == rustc_span::sym::Return
1070 {
1071 if let ty::Generator(_, substs, _) = substs.type_at(0).kind() {
1072 let return_ty = substs.as_generator().return_ty();
1073 if !return_ty.is_ty_var() {
1074 return_ty.into()
1075 } else {
1076 continue;
1077 }
1078 } else {
1079 continue;
1080 }
1081 } else {
1082 term.skip_binder()
1083 };
1084
1085 if first {
1086 p!("<");
1087 first = false;
1088 } else {
1089 p!(", ");
1090 }
1091
1092 p!(write("{} = ", tcx.associated_item(assoc_item_def_id).name));
1093
1094 match term.unpack() {
1095 TermKind::Ty(ty) => p!(print(ty)),
1096 TermKind::Const(c) => p!(print(c)),
1097 };
1098 }
1099
1100 if !first {
1101 p!(">");
1102 }
1103 }
1104
1105 first = false;
1106 Ok(cx)
1107 })?;
1108 }
1109
1110 if !is_sized {
1111 write!(self, "{}?Sized", if first { "" } else { " + " })?;
1112 } else if first {
1113 write!(self, "Sized")?;
1114 }
1115
1116 if !FORCE_TRIMMED_PATH.with(|flag| flag.get()) {
1117 for re in lifetimes {
1118 write!(self, " + ")?;
1119 self = self.print_region(re)?;
1120 }
1121 }
1122
1123 Ok(self)
1124 }
1125
1126 /// Insert the trait ref and optionally a projection type associated with it into either the
1127 /// traits map or fn_traits map, depending on if the trait is in the Fn* family of traits.
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>>, )1128 fn insert_trait_and_projection(
1129 &mut self,
1130 trait_ref: ty::PolyTraitRef<'tcx>,
1131 proj_ty: Option<(DefId, ty::Binder<'tcx, Term<'tcx>>)>,
1132 traits: &mut FxIndexMap<
1133 ty::PolyTraitRef<'tcx>,
1134 FxIndexMap<DefId, ty::Binder<'tcx, Term<'tcx>>>,
1135 >,
1136 fn_traits: &mut FxIndexMap<ty::PolyTraitRef<'tcx>, OpaqueFnEntry<'tcx>>,
1137 ) {
1138 let trait_def_id = trait_ref.def_id();
1139
1140 // If our trait_ref is FnOnce or any of its children, project it onto the parent FnOnce
1141 // super-trait ref and record it there.
1142 if let Some(fn_once_trait) = self.tcx().lang_items().fn_once_trait() {
1143 // If we have a FnOnce, then insert it into
1144 if trait_def_id == fn_once_trait {
1145 let entry = fn_traits.entry(trait_ref).or_default();
1146 // Optionally insert the return_ty as well.
1147 if let Some((_, ty)) = proj_ty {
1148 entry.return_ty = Some(ty);
1149 }
1150 entry.has_fn_once = true;
1151 return;
1152 } else if Some(trait_def_id) == self.tcx().lang_items().fn_mut_trait() {
1153 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
1154 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
1155 .unwrap();
1156
1157 fn_traits.entry(super_trait_ref).or_default().fn_mut_trait_ref = Some(trait_ref);
1158 return;
1159 } else if Some(trait_def_id) == self.tcx().lang_items().fn_trait() {
1160 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
1161 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
1162 .unwrap();
1163
1164 fn_traits.entry(super_trait_ref).or_default().fn_trait_ref = Some(trait_ref);
1165 return;
1166 }
1167 }
1168
1169 // Otherwise, just group our traits and projection types.
1170 traits.entry(trait_ref).or_default().extend(proj_ty);
1171 }
1172
pretty_print_inherent_projection( self, alias_ty: &ty::AliasTy<'tcx>, ) -> Result<Self::Path, Self::Error>1173 fn pretty_print_inherent_projection(
1174 self,
1175 alias_ty: &ty::AliasTy<'tcx>,
1176 ) -> Result<Self::Path, Self::Error> {
1177 let def_key = self.tcx().def_key(alias_ty.def_id);
1178 self.path_generic_args(
1179 |cx| {
1180 cx.path_append(
1181 |cx| cx.path_qualified(alias_ty.self_ty(), None),
1182 &def_key.disambiguated_data,
1183 )
1184 },
1185 &alias_ty.substs[1..],
1186 )
1187 }
1188
ty_infer_name(&self, _: ty::TyVid) -> Option<Symbol>1189 fn ty_infer_name(&self, _: ty::TyVid) -> Option<Symbol> {
1190 None
1191 }
1192
const_infer_name(&self, _: ty::ConstVid<'tcx>) -> Option<Symbol>1193 fn const_infer_name(&self, _: ty::ConstVid<'tcx>) -> Option<Symbol> {
1194 None
1195 }
1196
pretty_print_dyn_existential( mut self, predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>, ) -> Result<Self::DynExistential, Self::Error>1197 fn pretty_print_dyn_existential(
1198 mut self,
1199 predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
1200 ) -> Result<Self::DynExistential, Self::Error> {
1201 // Generate the main trait ref, including associated types.
1202 let mut first = true;
1203
1204 if let Some(principal) = predicates.principal() {
1205 self = self.wrap_binder(&principal, |principal, mut cx| {
1206 define_scoped_cx!(cx);
1207 p!(print_def_path(principal.def_id, &[]));
1208
1209 let mut resugared = false;
1210
1211 // Special-case `Fn(...) -> ...` and re-sugar it.
1212 let fn_trait_kind = cx.tcx().fn_trait_kind_from_def_id(principal.def_id);
1213 if !cx.should_print_verbose() && fn_trait_kind.is_some() {
1214 if let ty::Tuple(tys) = principal.substs.type_at(0).kind() {
1215 let mut projections = predicates.projection_bounds();
1216 if let (Some(proj), None) = (projections.next(), projections.next()) {
1217 p!(pretty_fn_sig(
1218 tys,
1219 false,
1220 proj.skip_binder().term.ty().expect("Return type was a const")
1221 ));
1222 resugared = true;
1223 }
1224 }
1225 }
1226
1227 // HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
1228 // in order to place the projections inside the `<...>`.
1229 if !resugared {
1230 // Use a type that can't appear in defaults of type parameters.
1231 let dummy_cx = Ty::new_fresh(cx.tcx(), 0);
1232 let principal = principal.with_self_ty(cx.tcx(), dummy_cx);
1233
1234 let args = cx
1235 .tcx()
1236 .generics_of(principal.def_id)
1237 .own_substs_no_defaults(cx.tcx(), principal.substs);
1238
1239 let mut projections = predicates.projection_bounds();
1240
1241 let mut args = args.iter().cloned();
1242 let arg0 = args.next();
1243 let projection0 = projections.next();
1244 if arg0.is_some() || projection0.is_some() {
1245 let args = arg0.into_iter().chain(args);
1246 let projections = projection0.into_iter().chain(projections);
1247
1248 p!(generic_delimiters(|mut cx| {
1249 cx = cx.comma_sep(args)?;
1250 if arg0.is_some() && projection0.is_some() {
1251 write!(cx, ", ")?;
1252 }
1253 cx.comma_sep(projections)
1254 }));
1255 }
1256 }
1257 Ok(cx)
1258 })?;
1259
1260 first = false;
1261 }
1262
1263 define_scoped_cx!(self);
1264
1265 // Builtin bounds.
1266 // FIXME(eddyb) avoid printing twice (needed to ensure
1267 // that the auto traits are sorted *and* printed via cx).
1268 let mut auto_traits: Vec<_> = predicates.auto_traits().collect();
1269
1270 // The auto traits come ordered by `DefPathHash`. While
1271 // `DefPathHash` is *stable* in the sense that it depends on
1272 // neither the host nor the phase of the moon, it depends
1273 // "pseudorandomly" on the compiler version and the target.
1274 //
1275 // To avoid causing instabilities in compiletest
1276 // output, sort the auto-traits alphabetically.
1277 auto_traits.sort_by_cached_key(|did| with_no_trimmed_paths!(self.tcx().def_path_str(*did)));
1278
1279 for def_id in auto_traits {
1280 if !first {
1281 p!(" + ");
1282 }
1283 first = false;
1284
1285 p!(print_def_path(def_id, &[]));
1286 }
1287
1288 Ok(self)
1289 }
1290
pretty_fn_sig( mut self, inputs: &[Ty<'tcx>], c_variadic: bool, output: Ty<'tcx>, ) -> Result<Self, Self::Error>1291 fn pretty_fn_sig(
1292 mut self,
1293 inputs: &[Ty<'tcx>],
1294 c_variadic: bool,
1295 output: Ty<'tcx>,
1296 ) -> Result<Self, Self::Error> {
1297 define_scoped_cx!(self);
1298
1299 p!("(", comma_sep(inputs.iter().copied()));
1300 if c_variadic {
1301 if !inputs.is_empty() {
1302 p!(", ");
1303 }
1304 p!("...");
1305 }
1306 p!(")");
1307 if !output.is_unit() {
1308 p!(" -> ", print(output));
1309 }
1310
1311 Ok(self)
1312 }
1313
pretty_print_const( mut self, ct: ty::Const<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1314 fn pretty_print_const(
1315 mut self,
1316 ct: ty::Const<'tcx>,
1317 print_ty: bool,
1318 ) -> Result<Self::Const, Self::Error> {
1319 define_scoped_cx!(self);
1320
1321 if self.should_print_verbose() {
1322 p!(write("{:?}", ct));
1323 return Ok(self);
1324 }
1325
1326 macro_rules! print_underscore {
1327 () => {{
1328 if print_ty {
1329 self = self.typed_value(
1330 |mut this| {
1331 write!(this, "_")?;
1332 Ok(this)
1333 },
1334 |this| this.print_type(ct.ty()),
1335 ": ",
1336 )?;
1337 } else {
1338 write!(self, "_")?;
1339 }
1340 }};
1341 }
1342
1343 match ct.kind() {
1344 ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs }) => {
1345 match self.tcx().def_kind(def) {
1346 DefKind::Const | DefKind::AssocConst => {
1347 p!(print_value_path(def, substs))
1348 }
1349 DefKind::AnonConst => {
1350 if def.is_local()
1351 && let span = self.tcx().def_span(def)
1352 && let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span)
1353 {
1354 p!(write("{}", snip))
1355 } else {
1356 // Do not call `print_value_path` as if a parent of this anon const is an impl it will
1357 // attempt to print out the impl trait ref i.e. `<T as Trait>::{constant#0}`. This would
1358 // cause printing to enter an infinite recursion if the anon const is in the self type i.e.
1359 // `impl<T: Default> Default for [T; 32 - 1 - 1 - 1] {`
1360 // where we would try to print `<[T; /* print `constant#0` again */] as Default>::{constant#0}`
1361 p!(write("{}::{}", self.tcx().crate_name(def.krate), self.tcx().def_path(def).to_string_no_crate_verbose()))
1362 }
1363 }
1364 defkind => bug!("`{:?}` has unexpected defkind {:?}", ct, defkind),
1365 }
1366 }
1367 ty::ConstKind::Infer(infer_ct) => {
1368 match infer_ct {
1369 ty::InferConst::Var(ct_vid)
1370 if let Some(name) = self.const_infer_name(ct_vid) =>
1371 p!(write("{}", name)),
1372 _ => print_underscore!(),
1373 }
1374 }
1375 ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
1376 ty::ConstKind::Value(value) => {
1377 return self.pretty_print_const_valtree(value, ct.ty(), print_ty);
1378 }
1379
1380 ty::ConstKind::Bound(debruijn, bound_var) => {
1381 rustc_type_ir::debug_bound_var(&mut self, debruijn, bound_var)?
1382 }
1383 ty::ConstKind::Placeholder(placeholder) => p!(write("{placeholder:?}")),
1384 // FIXME(generic_const_exprs):
1385 // write out some legible representation of an abstract const?
1386 ty::ConstKind::Expr(_) => p!("{{const expr}}"),
1387 ty::ConstKind::Error(_) => p!("{{const error}}"),
1388 };
1389 Ok(self)
1390 }
1391
pretty_print_const_scalar( self, scalar: Scalar, ty: Ty<'tcx>, ) -> Result<Self::Const, Self::Error>1392 fn pretty_print_const_scalar(
1393 self,
1394 scalar: Scalar,
1395 ty: Ty<'tcx>,
1396 ) -> Result<Self::Const, Self::Error> {
1397 match scalar {
1398 Scalar::Ptr(ptr, _size) => self.pretty_print_const_scalar_ptr(ptr, ty),
1399 Scalar::Int(int) => {
1400 self.pretty_print_const_scalar_int(int, ty, /* print_ty */ true)
1401 }
1402 }
1403 }
1404
pretty_print_const_scalar_ptr( mut self, ptr: Pointer, ty: Ty<'tcx>, ) -> Result<Self::Const, Self::Error>1405 fn pretty_print_const_scalar_ptr(
1406 mut self,
1407 ptr: Pointer,
1408 ty: Ty<'tcx>,
1409 ) -> Result<Self::Const, Self::Error> {
1410 define_scoped_cx!(self);
1411
1412 let (alloc_id, offset) = ptr.into_parts();
1413 match ty.kind() {
1414 // Byte strings (&[u8; N])
1415 ty::Ref(_, inner, _) => {
1416 if let ty::Array(elem, len) = inner.kind() {
1417 if let ty::Uint(ty::UintTy::U8) = elem.kind() {
1418 if let ty::ConstKind::Value(ty::ValTree::Leaf(int)) = len.kind() {
1419 match self.tcx().try_get_global_alloc(alloc_id) {
1420 Some(GlobalAlloc::Memory(alloc)) => {
1421 let len = int.assert_bits(self.tcx().data_layout.pointer_size);
1422 let range =
1423 AllocRange { start: offset, size: Size::from_bytes(len) };
1424 if let Ok(byte_str) =
1425 alloc.inner().get_bytes_strip_provenance(&self.tcx(), range)
1426 {
1427 p!(pretty_print_byte_str(byte_str))
1428 } else {
1429 p!("<too short allocation>")
1430 }
1431 }
1432 // FIXME: for statics, vtables, and functions, we could in principle print more detail.
1433 Some(GlobalAlloc::Static(def_id)) => {
1434 p!(write("<static({:?})>", def_id))
1435 }
1436 Some(GlobalAlloc::Function(_)) => p!("<function>"),
1437 Some(GlobalAlloc::VTable(..)) => p!("<vtable>"),
1438 None => p!("<dangling pointer>"),
1439 }
1440 return Ok(self);
1441 }
1442 }
1443 }
1444 }
1445 ty::FnPtr(_) => {
1446 // FIXME: We should probably have a helper method to share code with the "Byte strings"
1447 // printing above (which also has to handle pointers to all sorts of things).
1448 if let Some(GlobalAlloc::Function(instance)) =
1449 self.tcx().try_get_global_alloc(alloc_id)
1450 {
1451 self = self.typed_value(
1452 |this| this.print_value_path(instance.def_id(), instance.substs),
1453 |this| this.print_type(ty),
1454 " as ",
1455 )?;
1456 return Ok(self);
1457 }
1458 }
1459 _ => {}
1460 }
1461 // Any pointer values not covered by a branch above
1462 self = self.pretty_print_const_pointer(ptr, ty)?;
1463 Ok(self)
1464 }
1465
pretty_print_const_scalar_int( mut self, int: ScalarInt, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1466 fn pretty_print_const_scalar_int(
1467 mut self,
1468 int: ScalarInt,
1469 ty: Ty<'tcx>,
1470 print_ty: bool,
1471 ) -> Result<Self::Const, Self::Error> {
1472 define_scoped_cx!(self);
1473
1474 match ty.kind() {
1475 // Bool
1476 ty::Bool if int == ScalarInt::FALSE => p!("false"),
1477 ty::Bool if int == ScalarInt::TRUE => p!("true"),
1478 // Float
1479 ty::Float(ty::FloatTy::F32) => {
1480 p!(write("{}f32", Single::try_from(int).unwrap()))
1481 }
1482 ty::Float(ty::FloatTy::F64) => {
1483 p!(write("{}f64", Double::try_from(int).unwrap()))
1484 }
1485 // Int
1486 ty::Uint(_) | ty::Int(_) => {
1487 let int =
1488 ConstInt::new(int, matches!(ty.kind(), ty::Int(_)), ty.is_ptr_sized_integral());
1489 if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
1490 }
1491 // Char
1492 ty::Char if char::try_from(int).is_ok() => {
1493 p!(write("{:?}", char::try_from(int).unwrap()))
1494 }
1495 // Pointer types
1496 ty::Ref(..) | ty::RawPtr(_) | ty::FnPtr(_) => {
1497 let data = int.assert_bits(self.tcx().data_layout.pointer_size);
1498 self = self.typed_value(
1499 |mut this| {
1500 write!(this, "0x{:x}", data)?;
1501 Ok(this)
1502 },
1503 |this| this.print_type(ty),
1504 " as ",
1505 )?;
1506 }
1507 // Nontrivial types with scalar bit representation
1508 _ => {
1509 let print = |mut this: Self| {
1510 if int.size() == Size::ZERO {
1511 write!(this, "transmute(())")?;
1512 } else {
1513 write!(this, "transmute(0x{:x})", int)?;
1514 }
1515 Ok(this)
1516 };
1517 self = if print_ty {
1518 self.typed_value(print, |this| this.print_type(ty), ": ")?
1519 } else {
1520 print(self)?
1521 };
1522 }
1523 }
1524 Ok(self)
1525 }
1526
1527 /// This is overridden for MIR printing because we only want to hide alloc ids from users, not
1528 /// from MIR where it is actually useful.
pretty_print_const_pointer<Prov: Provenance>( self, _: Pointer<Prov>, ty: Ty<'tcx>, ) -> Result<Self::Const, Self::Error>1529 fn pretty_print_const_pointer<Prov: Provenance>(
1530 self,
1531 _: Pointer<Prov>,
1532 ty: Ty<'tcx>,
1533 ) -> Result<Self::Const, Self::Error> {
1534 self.typed_value(
1535 |mut this| {
1536 this.write_str("&_")?;
1537 Ok(this)
1538 },
1539 |this| this.print_type(ty),
1540 ": ",
1541 )
1542 }
1543
pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error>1544 fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
1545 write!(self, "b\"{}\"", byte_str.escape_ascii())?;
1546 Ok(self)
1547 }
1548
pretty_print_const_valtree( mut self, valtree: ty::ValTree<'tcx>, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1549 fn pretty_print_const_valtree(
1550 mut self,
1551 valtree: ty::ValTree<'tcx>,
1552 ty: Ty<'tcx>,
1553 print_ty: bool,
1554 ) -> Result<Self::Const, Self::Error> {
1555 define_scoped_cx!(self);
1556
1557 if self.should_print_verbose() {
1558 p!(write("ValTree({:?}: ", valtree), print(ty), ")");
1559 return Ok(self);
1560 }
1561
1562 let u8_type = self.tcx().types.u8;
1563 match (valtree, ty.kind()) {
1564 (ty::ValTree::Branch(_), ty::Ref(_, inner_ty, _)) => match inner_ty.kind() {
1565 ty::Slice(t) if *t == u8_type => {
1566 let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
1567 bug!(
1568 "expected to convert valtree {:?} to raw bytes for type {:?}",
1569 valtree,
1570 t
1571 )
1572 });
1573 return self.pretty_print_byte_str(bytes);
1574 }
1575 ty::Str => {
1576 let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
1577 bug!("expected to convert valtree to raw bytes for type {:?}", ty)
1578 });
1579 p!(write("{:?}", String::from_utf8_lossy(bytes)));
1580 return Ok(self);
1581 }
1582 _ => {
1583 p!("&");
1584 p!(pretty_print_const_valtree(valtree, *inner_ty, print_ty));
1585 return Ok(self);
1586 }
1587 },
1588 (ty::ValTree::Branch(_), ty::Array(t, _)) if *t == u8_type => {
1589 let bytes = valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
1590 bug!("expected to convert valtree to raw bytes for type {:?}", t)
1591 });
1592 p!("*");
1593 p!(pretty_print_byte_str(bytes));
1594 return Ok(self);
1595 }
1596 // Aggregates, printed as array/tuple/struct/variant construction syntax.
1597 (ty::ValTree::Branch(_), ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) => {
1598 let contents =
1599 self.tcx().destructure_const(ty::Const::new_value(self.tcx(), valtree, ty));
1600 let fields = contents.fields.iter().copied();
1601 match *ty.kind() {
1602 ty::Array(..) => {
1603 p!("[", comma_sep(fields), "]");
1604 }
1605 ty::Tuple(..) => {
1606 p!("(", comma_sep(fields));
1607 if contents.fields.len() == 1 {
1608 p!(",");
1609 }
1610 p!(")");
1611 }
1612 ty::Adt(def, _) if def.variants().is_empty() => {
1613 self = self.typed_value(
1614 |mut this| {
1615 write!(this, "unreachable()")?;
1616 Ok(this)
1617 },
1618 |this| this.print_type(ty),
1619 ": ",
1620 )?;
1621 }
1622 ty::Adt(def, substs) => {
1623 let variant_idx =
1624 contents.variant.expect("destructed const of adt without variant idx");
1625 let variant_def = &def.variant(variant_idx);
1626 p!(print_value_path(variant_def.def_id, substs));
1627 match variant_def.ctor_kind() {
1628 Some(CtorKind::Const) => {}
1629 Some(CtorKind::Fn) => {
1630 p!("(", comma_sep(fields), ")");
1631 }
1632 None => {
1633 p!(" {{ ");
1634 let mut first = true;
1635 for (field_def, field) in iter::zip(&variant_def.fields, fields) {
1636 if !first {
1637 p!(", ");
1638 }
1639 p!(write("{}: ", field_def.name), print(field));
1640 first = false;
1641 }
1642 p!(" }}");
1643 }
1644 }
1645 }
1646 _ => unreachable!(),
1647 }
1648 return Ok(self);
1649 }
1650 (ty::ValTree::Leaf(leaf), ty::Ref(_, inner_ty, _)) => {
1651 p!(write("&"));
1652 return self.pretty_print_const_scalar_int(leaf, *inner_ty, print_ty);
1653 }
1654 (ty::ValTree::Leaf(leaf), _) => {
1655 return self.pretty_print_const_scalar_int(leaf, ty, print_ty);
1656 }
1657 // FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
1658 // their fields instead of just dumping the memory.
1659 _ => {}
1660 }
1661
1662 // fallback
1663 if valtree == ty::ValTree::zst() {
1664 p!(write("<ZST>"));
1665 } else {
1666 p!(write("{:?}", valtree));
1667 }
1668 if print_ty {
1669 p!(": ", print(ty));
1670 }
1671 Ok(self)
1672 }
1673
pretty_closure_as_impl( mut self, closure: ty::ClosureSubsts<'tcx>, ) -> Result<Self::Const, Self::Error>1674 fn pretty_closure_as_impl(
1675 mut self,
1676 closure: ty::ClosureSubsts<'tcx>,
1677 ) -> Result<Self::Const, Self::Error> {
1678 let sig = closure.sig();
1679 let kind = closure.kind_ty().to_opt_closure_kind().unwrap_or(ty::ClosureKind::Fn);
1680
1681 write!(self, "impl ")?;
1682 self.wrap_binder(&sig, |sig, mut cx| {
1683 define_scoped_cx!(cx);
1684
1685 p!(print(kind), "(");
1686 for (i, arg) in sig.inputs()[0].tuple_fields().iter().enumerate() {
1687 if i > 0 {
1688 p!(", ");
1689 }
1690 p!(print(arg));
1691 }
1692 p!(")");
1693
1694 if !sig.output().is_unit() {
1695 p!(" -> ", print(sig.output()));
1696 }
1697
1698 Ok(cx)
1699 })
1700 }
1701
should_print_verbose(&self) -> bool1702 fn should_print_verbose(&self) -> bool {
1703 self.tcx().sess.verbose()
1704 }
1705 }
1706
1707 // HACK(eddyb) boxed to avoid moving around a large struct by-value.
1708 pub struct FmtPrinter<'a, 'tcx>(Box<FmtPrinterData<'a, 'tcx>>);
1709
1710 pub struct FmtPrinterData<'a, 'tcx> {
1711 tcx: TyCtxt<'tcx>,
1712 fmt: String,
1713
1714 empty_path: bool,
1715 in_value: bool,
1716 pub print_alloc_ids: bool,
1717
1718 // set of all named (non-anonymous) region names
1719 used_region_names: FxHashSet<Symbol>,
1720
1721 region_index: usize,
1722 binder_depth: usize,
1723 printed_type_count: usize,
1724 type_length_limit: Limit,
1725 truncated: bool,
1726
1727 pub region_highlight_mode: RegionHighlightMode<'tcx>,
1728
1729 pub ty_infer_name_resolver: Option<Box<dyn Fn(ty::TyVid) -> Option<Symbol> + 'a>>,
1730 pub const_infer_name_resolver: Option<Box<dyn Fn(ty::ConstVid<'tcx>) -> Option<Symbol> + 'a>>,
1731 }
1732
1733 impl<'a, 'tcx> Deref for FmtPrinter<'a, 'tcx> {
1734 type Target = FmtPrinterData<'a, 'tcx>;
deref(&self) -> &Self::Target1735 fn deref(&self) -> &Self::Target {
1736 &self.0
1737 }
1738 }
1739
1740 impl DerefMut for FmtPrinter<'_, '_> {
deref_mut(&mut self) -> &mut Self::Target1741 fn deref_mut(&mut self) -> &mut Self::Target {
1742 &mut self.0
1743 }
1744 }
1745
1746 impl<'a, 'tcx> FmtPrinter<'a, 'tcx> {
new(tcx: TyCtxt<'tcx>, ns: Namespace) -> Self1747 pub fn new(tcx: TyCtxt<'tcx>, ns: Namespace) -> Self {
1748 let limit = if with_no_queries() { Limit::new(1048576) } else { tcx.type_length_limit() };
1749 Self::new_with_limit(tcx, ns, limit)
1750 }
1751
new_with_limit(tcx: TyCtxt<'tcx>, ns: Namespace, type_length_limit: Limit) -> Self1752 pub fn new_with_limit(tcx: TyCtxt<'tcx>, ns: Namespace, type_length_limit: Limit) -> Self {
1753 FmtPrinter(Box::new(FmtPrinterData {
1754 tcx,
1755 // Estimated reasonable capacity to allocate upfront based on a few
1756 // benchmarks.
1757 fmt: String::with_capacity(64),
1758 empty_path: false,
1759 in_value: ns == Namespace::ValueNS,
1760 print_alloc_ids: false,
1761 used_region_names: Default::default(),
1762 region_index: 0,
1763 binder_depth: 0,
1764 printed_type_count: 0,
1765 type_length_limit,
1766 truncated: false,
1767 region_highlight_mode: RegionHighlightMode::new(tcx),
1768 ty_infer_name_resolver: None,
1769 const_infer_name_resolver: None,
1770 }))
1771 }
1772
into_buffer(self) -> String1773 pub fn into_buffer(self) -> String {
1774 self.0.fmt
1775 }
1776 }
1777
1778 // HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
1779 // (but also some things just print a `DefId` generally so maybe we need this?)
guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace1780 fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
1781 match tcx.def_key(def_id).disambiguated_data.data {
1782 DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
1783 Namespace::TypeNS
1784 }
1785
1786 DefPathData::ValueNs(..)
1787 | DefPathData::AnonConst
1788 | DefPathData::ClosureExpr
1789 | DefPathData::Ctor => Namespace::ValueNS,
1790
1791 DefPathData::MacroNs(..) => Namespace::MacroNS,
1792
1793 _ => Namespace::TypeNS,
1794 }
1795 }
1796
1797 impl<'t> TyCtxt<'t> {
1798 /// Returns a string identifying this `DefId`. This string is
1799 /// suitable for user output.
def_path_str(self, def_id: impl IntoQueryParam<DefId>) -> String1800 pub fn def_path_str(self, def_id: impl IntoQueryParam<DefId>) -> String {
1801 self.def_path_str_with_substs(def_id, &[])
1802 }
1803
def_path_str_with_substs( self, def_id: impl IntoQueryParam<DefId>, substs: &'t [GenericArg<'t>], ) -> String1804 pub fn def_path_str_with_substs(
1805 self,
1806 def_id: impl IntoQueryParam<DefId>,
1807 substs: &'t [GenericArg<'t>],
1808 ) -> String {
1809 let def_id = def_id.into_query_param();
1810 let ns = guess_def_namespace(self, def_id);
1811 debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
1812 FmtPrinter::new(self, ns).print_def_path(def_id, substs).unwrap().into_buffer()
1813 }
1814
value_path_str_with_substs( self, def_id: impl IntoQueryParam<DefId>, substs: &'t [GenericArg<'t>], ) -> String1815 pub fn value_path_str_with_substs(
1816 self,
1817 def_id: impl IntoQueryParam<DefId>,
1818 substs: &'t [GenericArg<'t>],
1819 ) -> String {
1820 let def_id = def_id.into_query_param();
1821 let ns = guess_def_namespace(self, def_id);
1822 debug!("value_path_str: def_id={:?}, ns={:?}", def_id, ns);
1823 FmtPrinter::new(self, ns).print_value_path(def_id, substs).unwrap().into_buffer()
1824 }
1825 }
1826
1827 impl fmt::Write for FmtPrinter<'_, '_> {
write_str(&mut self, s: &str) -> fmt::Result1828 fn write_str(&mut self, s: &str) -> fmt::Result {
1829 self.fmt.push_str(s);
1830 Ok(())
1831 }
1832 }
1833
1834 impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
1835 type Error = fmt::Error;
1836
1837 type Path = Self;
1838 type Region = Self;
1839 type Type = Self;
1840 type DynExistential = Self;
1841 type Const = Self;
1842
tcx<'a>(&'a self) -> TyCtxt<'tcx>1843 fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
1844 self.tcx
1845 }
1846
print_def_path( mut self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>1847 fn print_def_path(
1848 mut self,
1849 def_id: DefId,
1850 substs: &'tcx [GenericArg<'tcx>],
1851 ) -> Result<Self::Path, Self::Error> {
1852 define_scoped_cx!(self);
1853
1854 if substs.is_empty() {
1855 match self.try_print_trimmed_def_path(def_id)? {
1856 (cx, true) => return Ok(cx),
1857 (cx, false) => self = cx,
1858 }
1859
1860 match self.try_print_visible_def_path(def_id)? {
1861 (cx, true) => return Ok(cx),
1862 (cx, false) => self = cx,
1863 }
1864 }
1865
1866 let key = self.tcx.def_key(def_id);
1867 if let DefPathData::Impl = key.disambiguated_data.data {
1868 // Always use types for non-local impls, where types are always
1869 // available, and filename/line-number is mostly uninteresting.
1870 let use_types = !def_id.is_local() || {
1871 // Otherwise, use filename/line-number if forced.
1872 let force_no_types = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
1873 !force_no_types
1874 };
1875
1876 if !use_types {
1877 // If no type info is available, fall back to
1878 // pretty printing some span information. This should
1879 // only occur very early in the compiler pipeline.
1880 let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
1881 let span = self.tcx.def_span(def_id);
1882
1883 self = self.print_def_path(parent_def_id, &[])?;
1884
1885 // HACK(eddyb) copy of `path_append` to avoid
1886 // constructing a `DisambiguatedDefPathData`.
1887 if !self.empty_path {
1888 write!(self, "::")?;
1889 }
1890 write!(
1891 self,
1892 "<impl at {}>",
1893 // This may end up in stderr diagnostics but it may also be emitted
1894 // into MIR. Hence we use the remapped path if available
1895 self.tcx.sess.source_map().span_to_embeddable_string(span)
1896 )?;
1897 self.empty_path = false;
1898
1899 return Ok(self);
1900 }
1901 }
1902
1903 self.default_print_def_path(def_id, substs)
1904 }
1905
print_region(self, region: ty::Region<'tcx>) -> Result<Self::Region, Self::Error>1906 fn print_region(self, region: ty::Region<'tcx>) -> Result<Self::Region, Self::Error> {
1907 self.pretty_print_region(region)
1908 }
1909
print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error>1910 fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
1911 if self.type_length_limit.value_within_limit(self.printed_type_count) {
1912 self.printed_type_count += 1;
1913 self.pretty_print_type(ty)
1914 } else {
1915 self.truncated = true;
1916 write!(self, "...")?;
1917 Ok(self)
1918 }
1919 }
1920
print_dyn_existential( self, predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>, ) -> Result<Self::DynExistential, Self::Error>1921 fn print_dyn_existential(
1922 self,
1923 predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
1924 ) -> Result<Self::DynExistential, Self::Error> {
1925 self.pretty_print_dyn_existential(predicates)
1926 }
1927
print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error>1928 fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
1929 self.pretty_print_const(ct, false)
1930 }
1931
path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error>1932 fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
1933 self.empty_path = true;
1934 if cnum == LOCAL_CRATE {
1935 if self.tcx.sess.rust_2018() {
1936 // We add the `crate::` keyword on Rust 2018, only when desired.
1937 if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
1938 write!(self, "{}", kw::Crate)?;
1939 self.empty_path = false;
1940 }
1941 }
1942 } else {
1943 write!(self, "{}", self.tcx.crate_name(cnum))?;
1944 self.empty_path = false;
1945 }
1946 Ok(self)
1947 }
1948
path_qualified( mut self, self_ty: Ty<'tcx>, trait_ref: Option<ty::TraitRef<'tcx>>, ) -> Result<Self::Path, Self::Error>1949 fn path_qualified(
1950 mut self,
1951 self_ty: Ty<'tcx>,
1952 trait_ref: Option<ty::TraitRef<'tcx>>,
1953 ) -> Result<Self::Path, Self::Error> {
1954 self = self.pretty_path_qualified(self_ty, trait_ref)?;
1955 self.empty_path = false;
1956 Ok(self)
1957 }
1958
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>1959 fn path_append_impl(
1960 mut self,
1961 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1962 _disambiguated_data: &DisambiguatedDefPathData,
1963 self_ty: Ty<'tcx>,
1964 trait_ref: Option<ty::TraitRef<'tcx>>,
1965 ) -> Result<Self::Path, Self::Error> {
1966 self = self.pretty_path_append_impl(
1967 |mut cx| {
1968 cx = print_prefix(cx)?;
1969 if !cx.empty_path {
1970 write!(cx, "::")?;
1971 }
1972
1973 Ok(cx)
1974 },
1975 self_ty,
1976 trait_ref,
1977 )?;
1978 self.empty_path = false;
1979 Ok(self)
1980 }
1981
path_append( mut self, print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, disambiguated_data: &DisambiguatedDefPathData, ) -> Result<Self::Path, Self::Error>1982 fn path_append(
1983 mut self,
1984 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1985 disambiguated_data: &DisambiguatedDefPathData,
1986 ) -> Result<Self::Path, Self::Error> {
1987 self = print_prefix(self)?;
1988
1989 // Skip `::{{extern}}` blocks and `::{{constructor}}` on tuple/unit structs.
1990 if let DefPathData::ForeignMod | DefPathData::Ctor = disambiguated_data.data {
1991 return Ok(self);
1992 }
1993
1994 let name = disambiguated_data.data.name();
1995 if !self.empty_path {
1996 write!(self, "::")?;
1997 }
1998
1999 if let DefPathDataName::Named(name) = name {
2000 if Ident::with_dummy_span(name).is_raw_guess() {
2001 write!(self, "r#")?;
2002 }
2003 }
2004
2005 let verbose = self.should_print_verbose();
2006 disambiguated_data.fmt_maybe_verbose(&mut self, verbose)?;
2007
2008 self.empty_path = false;
2009
2010 Ok(self)
2011 }
2012
path_generic_args( mut self, print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, args: &[GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>2013 fn path_generic_args(
2014 mut self,
2015 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
2016 args: &[GenericArg<'tcx>],
2017 ) -> Result<Self::Path, Self::Error> {
2018 self = print_prefix(self)?;
2019
2020 if args.first().is_some() {
2021 if self.in_value {
2022 write!(self, "::")?;
2023 }
2024 self.generic_delimiters(|cx| cx.comma_sep(args.iter().cloned()))
2025 } else {
2026 Ok(self)
2027 }
2028 }
2029 }
2030
2031 impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
ty_infer_name(&self, id: ty::TyVid) -> Option<Symbol>2032 fn ty_infer_name(&self, id: ty::TyVid) -> Option<Symbol> {
2033 self.0.ty_infer_name_resolver.as_ref().and_then(|func| func(id))
2034 }
2035
reset_type_limit(&mut self)2036 fn reset_type_limit(&mut self) {
2037 self.printed_type_count = 0;
2038 }
2039
const_infer_name(&self, id: ty::ConstVid<'tcx>) -> Option<Symbol>2040 fn const_infer_name(&self, id: ty::ConstVid<'tcx>) -> Option<Symbol> {
2041 self.0.const_infer_name_resolver.as_ref().and_then(|func| func(id))
2042 }
2043
print_value_path( mut self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>2044 fn print_value_path(
2045 mut self,
2046 def_id: DefId,
2047 substs: &'tcx [GenericArg<'tcx>],
2048 ) -> Result<Self::Path, Self::Error> {
2049 let was_in_value = std::mem::replace(&mut self.in_value, true);
2050 self = self.print_def_path(def_id, substs)?;
2051 self.in_value = was_in_value;
2052
2053 Ok(self)
2054 }
2055
in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,2056 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
2057 where
2058 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
2059 {
2060 self.pretty_in_binder(value)
2061 }
2062
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<TyCtxt<'tcx>>,2063 fn wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, Self::Error>>(
2064 self,
2065 value: &ty::Binder<'tcx, T>,
2066 f: C,
2067 ) -> Result<Self, Self::Error>
2068 where
2069 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
2070 {
2071 self.pretty_wrap_binder(value, f)
2072 }
2073
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>2074 fn typed_value(
2075 mut self,
2076 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
2077 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
2078 conversion: &str,
2079 ) -> Result<Self::Const, Self::Error> {
2080 self.write_str("{")?;
2081 self = f(self)?;
2082 self.write_str(conversion)?;
2083 let was_in_value = std::mem::replace(&mut self.in_value, false);
2084 self = t(self)?;
2085 self.in_value = was_in_value;
2086 self.write_str("}")?;
2087 Ok(self)
2088 }
2089
generic_delimiters( mut self, f: impl FnOnce(Self) -> Result<Self, Self::Error>, ) -> Result<Self, Self::Error>2090 fn generic_delimiters(
2091 mut self,
2092 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
2093 ) -> Result<Self, Self::Error> {
2094 write!(self, "<")?;
2095
2096 let was_in_value = std::mem::replace(&mut self.in_value, false);
2097 let mut inner = f(self)?;
2098 inner.in_value = was_in_value;
2099
2100 write!(inner, ">")?;
2101 Ok(inner)
2102 }
2103
should_print_region(&self, region: ty::Region<'tcx>) -> bool2104 fn should_print_region(&self, region: ty::Region<'tcx>) -> bool {
2105 let highlight = self.region_highlight_mode;
2106 if highlight.region_highlighted(region).is_some() {
2107 return true;
2108 }
2109
2110 if self.should_print_verbose() {
2111 return true;
2112 }
2113
2114 if FORCE_TRIMMED_PATH.with(|flag| flag.get()) {
2115 return false;
2116 }
2117
2118 let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
2119
2120 match *region {
2121 ty::ReEarlyBound(ref data) => data.has_name(),
2122
2123 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
2124 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
2125 | ty::RePlaceholder(ty::Placeholder {
2126 bound: ty::BoundRegion { kind: br, .. }, ..
2127 }) => {
2128 if br.is_named() {
2129 return true;
2130 }
2131
2132 if let Some((region, _)) = highlight.highlight_bound_region {
2133 if br == region {
2134 return true;
2135 }
2136 }
2137
2138 false
2139 }
2140
2141 ty::ReVar(_) if identify_regions => true,
2142
2143 ty::ReVar(_) | ty::ReErased | ty::ReError(_) => false,
2144
2145 ty::ReStatic => true,
2146 }
2147 }
2148
pretty_print_const_pointer<Prov: Provenance>( self, p: Pointer<Prov>, ty: Ty<'tcx>, ) -> Result<Self::Const, Self::Error>2149 fn pretty_print_const_pointer<Prov: Provenance>(
2150 self,
2151 p: Pointer<Prov>,
2152 ty: Ty<'tcx>,
2153 ) -> Result<Self::Const, Self::Error> {
2154 let print = |mut this: Self| {
2155 define_scoped_cx!(this);
2156 if this.print_alloc_ids {
2157 p!(write("{:?}", p));
2158 } else {
2159 p!("&_");
2160 }
2161 Ok(this)
2162 };
2163 self.typed_value(print, |this| this.print_type(ty), ": ")
2164 }
2165 }
2166
2167 // HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
2168 impl<'tcx> FmtPrinter<'_, 'tcx> {
pretty_print_region(mut self, region: ty::Region<'tcx>) -> Result<Self, fmt::Error>2169 pub fn pretty_print_region(mut self, region: ty::Region<'tcx>) -> Result<Self, fmt::Error> {
2170 define_scoped_cx!(self);
2171
2172 // Watch out for region highlights.
2173 let highlight = self.region_highlight_mode;
2174 if let Some(n) = highlight.region_highlighted(region) {
2175 p!(write("'{}", n));
2176 return Ok(self);
2177 }
2178
2179 if self.should_print_verbose() {
2180 p!(write("{:?}", region));
2181 return Ok(self);
2182 }
2183
2184 let identify_regions = self.tcx.sess.opts.unstable_opts.identify_regions;
2185
2186 // These printouts are concise. They do not contain all the information
2187 // the user might want to diagnose an error, but there is basically no way
2188 // to fit that into a short string. Hence the recommendation to use
2189 // `explain_region()` or `note_and_explain_region()`.
2190 match *region {
2191 ty::ReEarlyBound(ref data) => {
2192 if data.name != kw::Empty {
2193 p!(write("{}", data.name));
2194 return Ok(self);
2195 }
2196 }
2197 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
2198 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
2199 | ty::RePlaceholder(ty::Placeholder {
2200 bound: ty::BoundRegion { kind: br, .. }, ..
2201 }) => {
2202 if let ty::BrNamed(_, name) = br && br.is_named() {
2203 p!(write("{}", name));
2204 return Ok(self);
2205 }
2206
2207 if let Some((region, counter)) = highlight.highlight_bound_region {
2208 if br == region {
2209 p!(write("'{}", counter));
2210 return Ok(self);
2211 }
2212 }
2213 }
2214 ty::ReVar(region_vid) if identify_regions => {
2215 p!(write("{:?}", region_vid));
2216 return Ok(self);
2217 }
2218 ty::ReVar(_) => {}
2219 ty::ReErased => {}
2220 ty::ReError(_) => {}
2221 ty::ReStatic => {
2222 p!("'static");
2223 return Ok(self);
2224 }
2225 }
2226
2227 p!("'_");
2228
2229 Ok(self)
2230 }
2231 }
2232
2233 /// Folds through bound vars and placeholders, naming them
2234 struct RegionFolder<'a, 'tcx> {
2235 tcx: TyCtxt<'tcx>,
2236 current_index: ty::DebruijnIndex,
2237 region_map: BTreeMap<ty::BoundRegion, ty::Region<'tcx>>,
2238 name: &'a mut (
2239 dyn FnMut(
2240 Option<ty::DebruijnIndex>, // Debruijn index of the folded late-bound region
2241 ty::DebruijnIndex, // Index corresponding to binder level
2242 ty::BoundRegion,
2243 ) -> ty::Region<'tcx>
2244 + 'a
2245 ),
2246 }
2247
2248 impl<'a, 'tcx> ty::TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
interner(&self) -> TyCtxt<'tcx>2249 fn interner(&self) -> TyCtxt<'tcx> {
2250 self.tcx
2251 }
2252
fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>( &mut self, t: ty::Binder<'tcx, T>, ) -> ty::Binder<'tcx, T>2253 fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
2254 &mut self,
2255 t: ty::Binder<'tcx, T>,
2256 ) -> ty::Binder<'tcx, T> {
2257 self.current_index.shift_in(1);
2258 let t = t.super_fold_with(self);
2259 self.current_index.shift_out(1);
2260 t
2261 }
2262
fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx>2263 fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
2264 match *t.kind() {
2265 _ if t.has_vars_bound_at_or_above(self.current_index) || t.has_placeholders() => {
2266 return t.super_fold_with(self);
2267 }
2268 _ => {}
2269 }
2270 t
2271 }
2272
fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx>2273 fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
2274 let name = &mut self.name;
2275 let region = match *r {
2276 ty::ReLateBound(db, br) if db >= self.current_index => {
2277 *self.region_map.entry(br).or_insert_with(|| name(Some(db), self.current_index, br))
2278 }
2279 ty::RePlaceholder(ty::PlaceholderRegion {
2280 bound: ty::BoundRegion { kind, .. },
2281 ..
2282 }) => {
2283 // If this is an anonymous placeholder, don't rename. Otherwise, in some
2284 // async fns, we get a `for<'r> Send` bound
2285 match kind {
2286 ty::BrAnon(..) | ty::BrEnv => r,
2287 _ => {
2288 // Index doesn't matter, since this is just for naming and these never get bound
2289 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind };
2290 *self
2291 .region_map
2292 .entry(br)
2293 .or_insert_with(|| name(None, self.current_index, br))
2294 }
2295 }
2296 }
2297 _ => return r,
2298 };
2299 if let ty::ReLateBound(debruijn1, br) = *region {
2300 assert_eq!(debruijn1, ty::INNERMOST);
2301 ty::Region::new_late_bound(self.tcx, self.current_index, br)
2302 } else {
2303 region
2304 }
2305 }
2306 }
2307
2308 // HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
2309 // `region_index` and `used_region_names`.
2310 impl<'tcx> FmtPrinter<'_, 'tcx> {
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<TyCtxt<'tcx>>,2311 pub fn name_all_regions<T>(
2312 mut self,
2313 value: &ty::Binder<'tcx, T>,
2314 ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
2315 where
2316 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
2317 {
2318 fn name_by_region_index(
2319 index: usize,
2320 available_names: &mut Vec<Symbol>,
2321 num_available: usize,
2322 ) -> Symbol {
2323 if let Some(name) = available_names.pop() {
2324 name
2325 } else {
2326 Symbol::intern(&format!("'z{}", index - num_available))
2327 }
2328 }
2329
2330 debug!("name_all_regions");
2331
2332 // Replace any anonymous late-bound regions with named
2333 // variants, using new unique identifiers, so that we can
2334 // clearly differentiate between named and unnamed regions in
2335 // the output. We'll probably want to tweak this over time to
2336 // decide just how much information to give.
2337 if self.binder_depth == 0 {
2338 self.prepare_region_info(value);
2339 }
2340
2341 debug!("self.used_region_names: {:?}", &self.used_region_names);
2342
2343 let mut empty = true;
2344 let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
2345 let w = if empty {
2346 empty = false;
2347 start
2348 } else {
2349 cont
2350 };
2351 let _ = write!(cx, "{}", w);
2352 };
2353 let do_continue = |cx: &mut Self, cont: Symbol| {
2354 let _ = write!(cx, "{}", cont);
2355 };
2356
2357 define_scoped_cx!(self);
2358
2359 let possible_names = ('a'..='z').rev().map(|s| Symbol::intern(&format!("'{s}")));
2360
2361 let mut available_names = possible_names
2362 .filter(|name| !self.used_region_names.contains(&name))
2363 .collect::<Vec<_>>();
2364 debug!(?available_names);
2365 let num_available = available_names.len();
2366
2367 let mut region_index = self.region_index;
2368 let mut next_name = |this: &Self| {
2369 let mut name;
2370
2371 loop {
2372 name = name_by_region_index(region_index, &mut available_names, num_available);
2373 region_index += 1;
2374
2375 if !this.used_region_names.contains(&name) {
2376 break;
2377 }
2378 }
2379
2380 name
2381 };
2382
2383 // If we want to print verbosely, then print *all* binders, even if they
2384 // aren't named. Eventually, we might just want this as the default, but
2385 // this is not *quite* right and changes the ordering of some output
2386 // anyways.
2387 let (new_value, map) = if self.should_print_verbose() {
2388 for var in value.bound_vars().iter() {
2389 start_or_continue(&mut self, "for<", ", ");
2390 write!(self, "{:?}", var)?;
2391 }
2392 start_or_continue(&mut self, "", "> ");
2393 (value.clone().skip_binder(), BTreeMap::default())
2394 } else {
2395 let tcx = self.tcx;
2396
2397 let trim_path = FORCE_TRIMMED_PATH.with(|flag| flag.get());
2398 // Closure used in `RegionFolder` to create names for anonymous late-bound
2399 // regions. We use two `DebruijnIndex`es (one for the currently folded
2400 // late-bound region and the other for the binder level) to determine
2401 // whether a name has already been created for the currently folded region,
2402 // see issue #102392.
2403 let mut name = |lifetime_idx: Option<ty::DebruijnIndex>,
2404 binder_level_idx: ty::DebruijnIndex,
2405 br: ty::BoundRegion| {
2406 let (name, kind) = match br.kind {
2407 ty::BrAnon(..) | ty::BrEnv => {
2408 let name = next_name(&self);
2409
2410 if let Some(lt_idx) = lifetime_idx {
2411 if lt_idx > binder_level_idx {
2412 let kind = ty::BrNamed(CRATE_DEF_ID.to_def_id(), name);
2413 return ty::Region::new_late_bound(
2414 tcx,
2415 ty::INNERMOST,
2416 ty::BoundRegion { var: br.var, kind },
2417 );
2418 }
2419 }
2420
2421 (name, ty::BrNamed(CRATE_DEF_ID.to_def_id(), name))
2422 }
2423 ty::BrNamed(def_id, kw::UnderscoreLifetime | kw::Empty) => {
2424 let name = next_name(&self);
2425
2426 if let Some(lt_idx) = lifetime_idx {
2427 if lt_idx > binder_level_idx {
2428 let kind = ty::BrNamed(def_id, name);
2429 return ty::Region::new_late_bound(
2430 tcx,
2431 ty::INNERMOST,
2432 ty::BoundRegion { var: br.var, kind },
2433 );
2434 }
2435 }
2436
2437 (name, ty::BrNamed(def_id, name))
2438 }
2439 ty::BrNamed(_, name) => {
2440 if let Some(lt_idx) = lifetime_idx {
2441 if lt_idx > binder_level_idx {
2442 let kind = br.kind;
2443 return ty::Region::new_late_bound(
2444 tcx,
2445 ty::INNERMOST,
2446 ty::BoundRegion { var: br.var, kind },
2447 );
2448 }
2449 }
2450
2451 (name, br.kind)
2452 }
2453 };
2454
2455 if !trim_path {
2456 start_or_continue(&mut self, "for<", ", ");
2457 do_continue(&mut self, name);
2458 }
2459 ty::Region::new_late_bound(
2460 tcx,
2461 ty::INNERMOST,
2462 ty::BoundRegion { var: br.var, kind },
2463 )
2464 };
2465 let mut folder = RegionFolder {
2466 tcx,
2467 current_index: ty::INNERMOST,
2468 name: &mut name,
2469 region_map: BTreeMap::new(),
2470 };
2471 let new_value = value.clone().skip_binder().fold_with(&mut folder);
2472 let region_map = folder.region_map;
2473 if !trim_path {
2474 start_or_continue(&mut self, "", "> ");
2475 }
2476 (new_value, region_map)
2477 };
2478
2479 self.binder_depth += 1;
2480 self.region_index = region_index;
2481 Ok((self, new_value, map))
2482 }
2483
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<TyCtxt<'tcx>>,2484 pub fn pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error>
2485 where
2486 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
2487 {
2488 let old_region_index = self.region_index;
2489 let (new, new_value, _) = self.name_all_regions(value)?;
2490 let mut inner = new_value.print(new)?;
2491 inner.region_index = old_region_index;
2492 inner.binder_depth -= 1;
2493 Ok(inner)
2494 }
2495
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<TyCtxt<'tcx>>,2496 pub fn pretty_wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
2497 self,
2498 value: &ty::Binder<'tcx, T>,
2499 f: C,
2500 ) -> Result<Self, fmt::Error>
2501 where
2502 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
2503 {
2504 let old_region_index = self.region_index;
2505 let (new, new_value, _) = self.name_all_regions(value)?;
2506 let mut inner = f(&new_value, new)?;
2507 inner.region_index = old_region_index;
2508 inner.binder_depth -= 1;
2509 Ok(inner)
2510 }
2511
prepare_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>) where T: TypeVisitable<TyCtxt<'tcx>>,2512 fn prepare_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
2513 where
2514 T: TypeVisitable<TyCtxt<'tcx>>,
2515 {
2516 struct RegionNameCollector<'tcx> {
2517 used_region_names: FxHashSet<Symbol>,
2518 type_collector: SsoHashSet<Ty<'tcx>>,
2519 }
2520
2521 impl<'tcx> RegionNameCollector<'tcx> {
2522 fn new() -> Self {
2523 RegionNameCollector {
2524 used_region_names: Default::default(),
2525 type_collector: SsoHashSet::new(),
2526 }
2527 }
2528 }
2529
2530 impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for RegionNameCollector<'tcx> {
2531 type BreakTy = ();
2532
2533 fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
2534 trace!("address: {:p}", r.0.0);
2535
2536 // Collect all named lifetimes. These allow us to prevent duplication
2537 // of already existing lifetime names when introducing names for
2538 // anonymous late-bound regions.
2539 if let Some(name) = r.get_name() {
2540 self.used_region_names.insert(name);
2541 }
2542
2543 ControlFlow::Continue(())
2544 }
2545
2546 // We collect types in order to prevent really large types from compiling for
2547 // a really long time. See issue #83150 for why this is necessary.
2548 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
2549 let not_previously_inserted = self.type_collector.insert(ty);
2550 if not_previously_inserted {
2551 ty.super_visit_with(self)
2552 } else {
2553 ControlFlow::Continue(())
2554 }
2555 }
2556 }
2557
2558 let mut collector = RegionNameCollector::new();
2559 value.visit_with(&mut collector);
2560 self.used_region_names = collector.used_region_names;
2561 self.region_index = 0;
2562 }
2563 }
2564
2565 impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
2566 where
2567 T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<TyCtxt<'tcx>>,
2568 {
2569 type Output = P;
2570 type Error = P::Error;
2571
print(&self, cx: P) -> Result<Self::Output, Self::Error>2572 fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
2573 cx.in_binder(self)
2574 }
2575 }
2576
2577 impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
2578 where
2579 T: Print<'tcx, P, Output = P, Error = P::Error>,
2580 U: Print<'tcx, P, Output = P, Error = P::Error>,
2581 {
2582 type Output = P;
2583 type Error = P::Error;
print(&self, mut cx: P) -> Result<Self::Output, Self::Error>2584 fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
2585 define_scoped_cx!(cx);
2586 p!(print(self.0), ": ", print(self.1));
2587 Ok(cx)
2588 }
2589 }
2590
2591 macro_rules! forward_display_to_print {
2592 ($($ty:ty),+) => {
2593 // Some of the $ty arguments may not actually use 'tcx
2594 $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
2595 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2596 ty::tls::with(|tcx| {
2597 let cx = tcx.lift(*self)
2598 .expect("could not lift for printing")
2599 .print(FmtPrinter::new(tcx, Namespace::TypeNS))?;
2600 f.write_str(&cx.into_buffer())?;
2601 Ok(())
2602 })
2603 }
2604 })+
2605 };
2606 }
2607
2608 macro_rules! define_print_and_forward_display {
2609 (($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
2610 $(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
2611 type Output = P;
2612 type Error = fmt::Error;
2613 fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
2614 #[allow(unused_mut)]
2615 let mut $cx = $cx;
2616 define_scoped_cx!($cx);
2617 let _: () = $print;
2618 #[allow(unreachable_code)]
2619 Ok($cx)
2620 }
2621 })+
2622
2623 forward_display_to_print!($($ty),+);
2624 };
2625 }
2626
2627 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2628 /// the trait path. That is, it will print `Trait<U>` instead of
2629 /// `<T as Trait<U>>`.
2630 #[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
2631 pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
2632
2633 impl<'tcx> rustc_errors::IntoDiagnosticArg for TraitRefPrintOnlyTraitPath<'tcx> {
into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static>2634 fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
2635 self.to_string().into_diagnostic_arg()
2636 }
2637 }
2638
2639 impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2640 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2641 fmt::Display::fmt(self, f)
2642 }
2643 }
2644
2645 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2646 /// the trait name. That is, it will print `Trait` instead of
2647 /// `<T as Trait<U>>`.
2648 #[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
2649 pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
2650
2651 impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2652 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2653 fmt::Display::fmt(self, f)
2654 }
2655 }
2656
2657 impl<'tcx> ty::TraitRef<'tcx> {
print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx>2658 pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
2659 TraitRefPrintOnlyTraitPath(self)
2660 }
2661
print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx>2662 pub fn print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx> {
2663 TraitRefPrintOnlyTraitName(self)
2664 }
2665 }
2666
2667 impl<'tcx> ty::Binder<'tcx, ty::TraitRef<'tcx>> {
print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>2668 pub fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
2669 self.map_bound(|tr| tr.print_only_trait_path())
2670 }
2671 }
2672
2673 #[derive(Copy, Clone, TypeFoldable, TypeVisitable, Lift)]
2674 pub struct TraitPredPrintModifiersAndPath<'tcx>(ty::TraitPredicate<'tcx>);
2675
2676 impl<'tcx> fmt::Debug for TraitPredPrintModifiersAndPath<'tcx> {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2677 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2678 fmt::Display::fmt(self, f)
2679 }
2680 }
2681
2682 impl<'tcx> ty::TraitPredicate<'tcx> {
print_modifiers_and_trait_path(self) -> TraitPredPrintModifiersAndPath<'tcx>2683 pub fn print_modifiers_and_trait_path(self) -> TraitPredPrintModifiersAndPath<'tcx> {
2684 TraitPredPrintModifiersAndPath(self)
2685 }
2686 }
2687
2688 impl<'tcx> ty::PolyTraitPredicate<'tcx> {
print_modifiers_and_trait_path( self, ) -> ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>>2689 pub fn print_modifiers_and_trait_path(
2690 self,
2691 ) -> ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>> {
2692 self.map_bound(TraitPredPrintModifiersAndPath)
2693 }
2694 }
2695
2696 #[derive(Debug, Copy, Clone, Lift)]
2697 pub struct PrintClosureAsImpl<'tcx> {
2698 pub closure: ty::ClosureSubsts<'tcx>,
2699 }
2700
2701 forward_display_to_print! {
2702 ty::Region<'tcx>,
2703 Ty<'tcx>,
2704 &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
2705 ty::Const<'tcx>,
2706
2707 // HACK(eddyb) these are exhaustive instead of generic,
2708 // because `for<'tcx>` isn't possible yet.
2709 ty::PolyExistentialPredicate<'tcx>,
2710 ty::Binder<'tcx, ty::TraitRef<'tcx>>,
2711 ty::Binder<'tcx, ty::ExistentialTraitRef<'tcx>>,
2712 ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>,
2713 ty::Binder<'tcx, TraitRefPrintOnlyTraitName<'tcx>>,
2714 ty::Binder<'tcx, ty::FnSig<'tcx>>,
2715 ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,
2716 ty::Binder<'tcx, TraitPredPrintModifiersAndPath<'tcx>>,
2717 ty::Binder<'tcx, ty::SubtypePredicate<'tcx>>,
2718 ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
2719 ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
2720 ty::Binder<'tcx, ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
2721
2722 ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
2723 ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
2724 }
2725
2726 define_print_and_forward_display! {
2727 (self, cx):
2728
2729 &'tcx ty::List<Ty<'tcx>> {
2730 p!("{{", comma_sep(self.iter()), "}}")
2731 }
2732
2733 ty::TypeAndMut<'tcx> {
2734 p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
2735 }
2736
2737 ty::ExistentialTraitRef<'tcx> {
2738 // Use a type that can't appear in defaults of type parameters.
2739 let dummy_self = Ty::new_fresh(cx.tcx(),0);
2740 let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
2741 p!(print(trait_ref.print_only_trait_path()))
2742 }
2743
2744 ty::ExistentialProjection<'tcx> {
2745 let name = cx.tcx().associated_item(self.def_id).name;
2746 p!(write("{} = ", name), print(self.term))
2747 }
2748
2749 ty::ExistentialPredicate<'tcx> {
2750 match *self {
2751 ty::ExistentialPredicate::Trait(x) => p!(print(x)),
2752 ty::ExistentialPredicate::Projection(x) => p!(print(x)),
2753 ty::ExistentialPredicate::AutoTrait(def_id) => {
2754 p!(print_def_path(def_id, &[]));
2755 }
2756 }
2757 }
2758
2759 ty::FnSig<'tcx> {
2760 p!(write("{}", self.unsafety.prefix_str()));
2761
2762 if self.abi != Abi::Rust {
2763 p!(write("extern {} ", self.abi));
2764 }
2765
2766 p!("fn", pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
2767 }
2768
2769 ty::TraitRef<'tcx> {
2770 p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
2771 }
2772
2773 TraitRefPrintOnlyTraitPath<'tcx> {
2774 p!(print_def_path(self.0.def_id, self.0.substs));
2775 }
2776
2777 TraitRefPrintOnlyTraitName<'tcx> {
2778 p!(print_def_path(self.0.def_id, &[]));
2779 }
2780
2781 TraitPredPrintModifiersAndPath<'tcx> {
2782 if let ty::BoundConstness::ConstIfConst = self.0.constness {
2783 p!("~const ")
2784 }
2785
2786 if let ty::ImplPolarity::Negative = self.0.polarity {
2787 p!("!")
2788 }
2789
2790 p!(print(self.0.trait_ref.print_only_trait_path()));
2791 }
2792
2793 PrintClosureAsImpl<'tcx> {
2794 p!(pretty_closure_as_impl(self.closure))
2795 }
2796
2797 ty::ParamTy {
2798 p!(write("{}", self.name))
2799 }
2800
2801 ty::ParamConst {
2802 p!(write("{}", self.name))
2803 }
2804
2805 ty::SubtypePredicate<'tcx> {
2806 p!(print(self.a), " <: ");
2807 cx.reset_type_limit();
2808 p!(print(self.b))
2809 }
2810
2811 ty::CoercePredicate<'tcx> {
2812 p!(print(self.a), " -> ");
2813 cx.reset_type_limit();
2814 p!(print(self.b))
2815 }
2816
2817 ty::TraitPredicate<'tcx> {
2818 p!(print(self.trait_ref.self_ty()), ": ");
2819 if let ty::BoundConstness::ConstIfConst = self.constness && cx.tcx().features().const_trait_impl {
2820 p!("~const ");
2821 }
2822 if let ty::ImplPolarity::Negative = self.polarity {
2823 p!("!");
2824 }
2825 p!(print(self.trait_ref.print_only_trait_path()))
2826 }
2827
2828 ty::ProjectionPredicate<'tcx> {
2829 p!(print(self.projection_ty), " == ");
2830 cx.reset_type_limit();
2831 p!(print(self.term))
2832 }
2833
2834 ty::Term<'tcx> {
2835 match self.unpack() {
2836 ty::TermKind::Ty(ty) => p!(print(ty)),
2837 ty::TermKind::Const(c) => p!(print(c)),
2838 }
2839 }
2840
2841 ty::AliasTy<'tcx> {
2842 if let DefKind::Impl { of_trait: false } = cx.tcx().def_kind(cx.tcx().parent(self.def_id)) {
2843 p!(pretty_print_inherent_projection(self))
2844 } else {
2845 p!(print_def_path(self.def_id, self.substs));
2846 }
2847 }
2848
2849 ty::ClosureKind {
2850 match *self {
2851 ty::ClosureKind::Fn => p!("Fn"),
2852 ty::ClosureKind::FnMut => p!("FnMut"),
2853 ty::ClosureKind::FnOnce => p!("FnOnce"),
2854 }
2855 }
2856
2857 ty::Predicate<'tcx> {
2858 let binder = self.kind();
2859 p!(print(binder))
2860 }
2861
2862 ty::Clause<'tcx> {
2863 p!(print(self.kind()))
2864 }
2865
2866 ty::ClauseKind<'tcx> {
2867 match *self {
2868 ty::ClauseKind::Trait(ref data) => {
2869 p!(print(data))
2870 }
2871 ty::ClauseKind::RegionOutlives(predicate) => p!(print(predicate)),
2872 ty::ClauseKind::TypeOutlives(predicate) => p!(print(predicate)),
2873 ty::ClauseKind::Projection(predicate) => p!(print(predicate)),
2874 ty::ClauseKind::ConstArgHasType(ct, ty) => {
2875 p!("the constant `", print(ct), "` has type `", print(ty), "`")
2876 },
2877 ty::ClauseKind::WellFormed(arg) => p!(print(arg), " well-formed"),
2878 ty::ClauseKind::ConstEvaluatable(ct) => {
2879 p!("the constant `", print(ct), "` can be evaluated")
2880 }
2881 }
2882 }
2883
2884 ty::PredicateKind<'tcx> {
2885 match *self {
2886 ty::PredicateKind::Clause(data) => {
2887 p!(print(data))
2888 }
2889 ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
2890 ty::PredicateKind::Coerce(predicate) => p!(print(predicate)),
2891 ty::PredicateKind::ObjectSafe(trait_def_id) => {
2892 p!("the trait `", print_def_path(trait_def_id, &[]), "` is object-safe")
2893 }
2894 ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => p!(
2895 "the closure `",
2896 print_value_path(closure_def_id, &[]),
2897 write("` implements the trait `{}`", kind)
2898 ),
2899 ty::PredicateKind::ConstEquate(c1, c2) => {
2900 p!("the constant `", print(c1), "` equals `", print(c2), "`")
2901 }
2902 ty::PredicateKind::Ambiguous => p!("ambiguous"),
2903 ty::PredicateKind::AliasRelate(t1, t2, dir) => p!(print(t1), write(" {} ", dir), print(t2)),
2904 }
2905 }
2906
2907 GenericArg<'tcx> {
2908 match self.unpack() {
2909 GenericArgKind::Lifetime(lt) => p!(print(lt)),
2910 GenericArgKind::Type(ty) => p!(print(ty)),
2911 GenericArgKind::Const(ct) => p!(print(ct)),
2912 }
2913 }
2914 }
2915
for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId))2916 fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId)) {
2917 // Iterate all local crate items no matter where they are defined.
2918 let hir = tcx.hir();
2919 for id in hir.items() {
2920 if matches!(tcx.def_kind(id.owner_id), DefKind::Use) {
2921 continue;
2922 }
2923
2924 let item = hir.item(id);
2925 if item.ident.name == kw::Empty {
2926 continue;
2927 }
2928
2929 let def_id = item.owner_id.to_def_id();
2930 let ns = tcx.def_kind(def_id).ns().unwrap_or(Namespace::TypeNS);
2931 collect_fn(&item.ident, ns, def_id);
2932 }
2933
2934 // Now take care of extern crate items.
2935 let queue = &mut Vec::new();
2936 let mut seen_defs: DefIdSet = Default::default();
2937
2938 for &cnum in tcx.crates(()).iter() {
2939 let def_id = cnum.as_def_id();
2940
2941 // Ignore crates that are not direct dependencies.
2942 match tcx.extern_crate(def_id) {
2943 None => continue,
2944 Some(extern_crate) => {
2945 if !extern_crate.is_direct() {
2946 continue;
2947 }
2948 }
2949 }
2950
2951 queue.push(def_id);
2952 }
2953
2954 // Iterate external crate defs but be mindful about visibility
2955 while let Some(def) = queue.pop() {
2956 for child in tcx.module_children(def).iter() {
2957 if !child.vis.is_public() {
2958 continue;
2959 }
2960
2961 match child.res {
2962 def::Res::Def(DefKind::AssocTy, _) => {}
2963 def::Res::Def(DefKind::TyAlias, _) => {}
2964 def::Res::Def(defkind, def_id) => {
2965 if let Some(ns) = defkind.ns() {
2966 collect_fn(&child.ident, ns, def_id);
2967 }
2968
2969 if matches!(defkind, DefKind::Mod | DefKind::Enum | DefKind::Trait)
2970 && seen_defs.insert(def_id)
2971 {
2972 queue.push(def_id);
2973 }
2974 }
2975 _ => {}
2976 }
2977 }
2978 }
2979 }
2980
2981 /// The purpose of this function is to collect public symbols names that are unique across all
2982 /// crates in the build. Later, when printing about types we can use those names instead of the
2983 /// full exported path to them.
2984 ///
2985 /// So essentially, if a symbol name can only be imported from one place for a type, and as
2986 /// long as it was not glob-imported anywhere in the current crate, we can trim its printed
2987 /// path and print only the name.
2988 ///
2989 /// This has wide implications on error messages with types, for example, shortening
2990 /// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere.
2991 ///
2992 /// The implementation uses similar import discovery logic to that of 'use' suggestions.
2993 ///
2994 /// See also [`DelayDm`](rustc_error_messages::DelayDm) and [`with_no_trimmed_paths!`].
trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol>2995 fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> {
2996 let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default();
2997
2998 if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
2999 // Trimming paths is expensive and not optimized, since we expect it to only be used for error reporting.
3000 //
3001 // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
3002 // wrapper can be used to suppress this query, in exchange for full paths being formatted.
3003 tcx.sess.delay_good_path_bug(
3004 "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging",
3005 );
3006 }
3007
3008 let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
3009 &mut FxHashMap::default();
3010
3011 for symbol_set in tcx.resolutions(()).glob_map.values() {
3012 for symbol in symbol_set {
3013 unique_symbols_rev.insert((Namespace::TypeNS, *symbol), None);
3014 unique_symbols_rev.insert((Namespace::ValueNS, *symbol), None);
3015 unique_symbols_rev.insert((Namespace::MacroNS, *symbol), None);
3016 }
3017 }
3018
3019 for_each_def(tcx, |ident, ns, def_id| {
3020 use std::collections::hash_map::Entry::{Occupied, Vacant};
3021
3022 match unique_symbols_rev.entry((ns, ident.name)) {
3023 Occupied(mut v) => match v.get() {
3024 None => {}
3025 Some(existing) => {
3026 if *existing != def_id {
3027 v.insert(None);
3028 }
3029 }
3030 },
3031 Vacant(v) => {
3032 v.insert(Some(def_id));
3033 }
3034 }
3035 });
3036
3037 for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
3038 use std::collections::hash_map::Entry::{Occupied, Vacant};
3039
3040 if let Some(def_id) = opt_def_id {
3041 match map.entry(def_id) {
3042 Occupied(mut v) => {
3043 // A single DefId can be known under multiple names (e.g.,
3044 // with a `pub use ... as ...;`). We need to ensure that the
3045 // name placed in this map is chosen deterministically, so
3046 // if we find multiple names (`symbol`) resolving to the
3047 // same `def_id`, we prefer the lexicographically smallest
3048 // name.
3049 //
3050 // Any stable ordering would be fine here though.
3051 if *v.get() != symbol {
3052 if v.get().as_str() > symbol.as_str() {
3053 v.insert(symbol);
3054 }
3055 }
3056 }
3057 Vacant(v) => {
3058 v.insert(symbol);
3059 }
3060 }
3061 }
3062 }
3063
3064 map
3065 }
3066
provide(providers: &mut Providers)3067 pub fn provide(providers: &mut Providers) {
3068 *providers = Providers { trimmed_def_paths, ..*providers };
3069 }
3070
3071 #[derive(Default)]
3072 pub struct OpaqueFnEntry<'tcx> {
3073 // The trait ref is already stored as a key, so just track if we have it as a real predicate
3074 has_fn_once: bool,
3075 fn_mut_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
3076 fn_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
3077 return_ty: Option<ty::Binder<'tcx, Term<'tcx>>>,
3078 }
3079