1 use crate::mir::interpret::{AllocRange, ConstValue, GlobalAlloc, Pointer, Provenance, Scalar};
2 use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
3 use crate::ty::{self, ConstInt, DefIdTree, ParamConst, ScalarInt, Ty, TyCtxt, TypeFoldable};
4 use rustc_apfloat::ieee::{Double, Single};
5 use rustc_data_structures::fx::FxHashMap;
6 use rustc_data_structures::sso::SsoHashSet;
7 use rustc_hir as hir;
8 use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
9 use rustc_hir::def_id::{DefId, DefIdSet, CRATE_DEF_INDEX, LOCAL_CRATE};
10 use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData};
11 use rustc_hir::ItemKind;
12 use rustc_session::config::TrimmedDefPaths;
13 use rustc_session::cstore::{ExternCrate, ExternCrateSource};
14 use rustc_span::symbol::{kw, Ident, Symbol};
15 use rustc_target::abi::Size;
16 use rustc_target::spec::abi::Abi;
17
18 use std::cell::Cell;
19 use std::char;
20 use std::collections::BTreeMap;
21 use std::convert::TryFrom;
22 use std::fmt::{self, Write as _};
23 use std::iter;
24 use std::ops::{ControlFlow, Deref, DerefMut};
25
26 // `pretty` is a separate module only for organization.
27 use super::*;
28
29 macro_rules! p {
30 (@$lit:literal) => {
31 write!(scoped_cx!(), $lit)?
32 };
33 (@write($($data:expr),+)) => {
34 write!(scoped_cx!(), $($data),+)?
35 };
36 (@print($x:expr)) => {
37 scoped_cx!() = $x.print(scoped_cx!())?
38 };
39 (@$method:ident($($arg:expr),*)) => {
40 scoped_cx!() = scoped_cx!().$method($($arg),*)?
41 };
42 ($($elem:tt $(($($args:tt)*))?),+) => {{
43 $(p!(@ $elem $(($($args)*))?);)+
44 }};
45 }
46 macro_rules! define_scoped_cx {
47 ($cx:ident) => {
48 #[allow(unused_macros)]
49 macro_rules! scoped_cx {
50 () => {
51 $cx
52 };
53 }
54 };
55 }
56
57 thread_local! {
58 static FORCE_IMPL_FILENAME_LINE: Cell<bool> = const { Cell::new(false) };
59 static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = const { Cell::new(false) };
60 static NO_TRIMMED_PATH: Cell<bool> = const { Cell::new(false) };
61 static NO_QUERIES: Cell<bool> = const { Cell::new(false) };
62 static NO_VISIBLE_PATH: Cell<bool> = const { Cell::new(false) };
63 }
64
65 /// Avoids running any queries during any prints that occur
66 /// during the closure. This may alter the appearance of some
67 /// types (e.g. forcing verbose printing for opaque types).
68 /// This method is used during some queries (e.g. `explicit_item_bounds`
69 /// for opaque types), to ensure that any debug printing that
70 /// occurs during the query computation does not end up recursively
71 /// calling the same query.
with_no_queries<F: FnOnce() -> R, R>(f: F) -> R72 pub fn with_no_queries<F: FnOnce() -> R, R>(f: F) -> R {
73 NO_QUERIES.with(|no_queries| {
74 let old = no_queries.replace(true);
75 let result = f();
76 no_queries.set(old);
77 result
78 })
79 }
80
81 /// Force us to name impls with just the filename/line number. We
82 /// normally try to use types. But at some points, notably while printing
83 /// cycle errors, this can result in extra or suboptimal error output,
84 /// so this variable disables that check.
with_forced_impl_filename_line<F: FnOnce() -> R, R>(f: F) -> R85 pub fn with_forced_impl_filename_line<F: FnOnce() -> R, R>(f: F) -> R {
86 FORCE_IMPL_FILENAME_LINE.with(|force| {
87 let old = force.replace(true);
88 let result = f();
89 force.set(old);
90 result
91 })
92 }
93
94 /// Adds the `crate::` prefix to paths where appropriate.
with_crate_prefix<F: FnOnce() -> R, R>(f: F) -> R95 pub fn with_crate_prefix<F: FnOnce() -> R, R>(f: F) -> R {
96 SHOULD_PREFIX_WITH_CRATE.with(|flag| {
97 let old = flag.replace(true);
98 let result = f();
99 flag.set(old);
100 result
101 })
102 }
103
104 /// Prevent path trimming if it is turned on. Path trimming affects `Display` impl
105 /// of various rustc types, for example `std::vec::Vec` would be trimmed to `Vec`,
106 /// if no other `Vec` is found.
with_no_trimmed_paths<F: FnOnce() -> R, R>(f: F) -> R107 pub fn with_no_trimmed_paths<F: FnOnce() -> R, R>(f: F) -> R {
108 NO_TRIMMED_PATH.with(|flag| {
109 let old = flag.replace(true);
110 let result = f();
111 flag.set(old);
112 result
113 })
114 }
115
116 /// Prevent selection of visible paths. `Display` impl of DefId will prefer visible (public) reexports of types as paths.
with_no_visible_paths<F: FnOnce() -> R, R>(f: F) -> R117 pub fn with_no_visible_paths<F: FnOnce() -> R, R>(f: F) -> R {
118 NO_VISIBLE_PATH.with(|flag| {
119 let old = flag.replace(true);
120 let result = f();
121 flag.set(old);
122 result
123 })
124 }
125
126 /// The "region highlights" are used to control region printing during
127 /// specific error messages. When a "region highlight" is enabled, it
128 /// gives an alternate way to print specific regions. For now, we
129 /// always print those regions using a number, so something like "`'0`".
130 ///
131 /// Regions not selected by the region highlight mode are presently
132 /// unaffected.
133 #[derive(Copy, Clone, Default)]
134 pub struct RegionHighlightMode {
135 /// If enabled, when we see the selected region, use "`'N`"
136 /// instead of the ordinary behavior.
137 highlight_regions: [Option<(ty::RegionKind, usize)>; 3],
138
139 /// If enabled, when printing a "free region" that originated from
140 /// the given `ty::BoundRegionKind`, print it as "`'1`". Free regions that would ordinarily
141 /// have names print as normal.
142 ///
143 /// This is used when you have a signature like `fn foo(x: &u32,
144 /// y: &'a u32)` and we want to give a name to the region of the
145 /// reference `x`.
146 highlight_bound_region: Option<(ty::BoundRegionKind, usize)>,
147 }
148
149 impl RegionHighlightMode {
150 /// If `region` and `number` are both `Some`, invokes
151 /// `highlighting_region`.
maybe_highlighting_region( &mut self, region: Option<ty::Region<'_>>, number: Option<usize>, )152 pub fn maybe_highlighting_region(
153 &mut self,
154 region: Option<ty::Region<'_>>,
155 number: Option<usize>,
156 ) {
157 if let Some(k) = region {
158 if let Some(n) = number {
159 self.highlighting_region(k, n);
160 }
161 }
162 }
163
164 /// Highlights the region inference variable `vid` as `'N`.
highlighting_region(&mut self, region: ty::Region<'_>, number: usize)165 pub fn highlighting_region(&mut self, region: ty::Region<'_>, number: usize) {
166 let num_slots = self.highlight_regions.len();
167 let first_avail_slot =
168 self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
169 bug!("can only highlight {} placeholders at a time", num_slots,)
170 });
171 *first_avail_slot = Some((*region, number));
172 }
173
174 /// Convenience wrapper for `highlighting_region`.
highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize)175 pub fn highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize) {
176 self.highlighting_region(&ty::ReVar(vid), number)
177 }
178
179 /// Returns `Some(n)` with the number to use for the given region, if any.
region_highlighted(&self, region: ty::Region<'_>) -> Option<usize>180 fn region_highlighted(&self, region: ty::Region<'_>) -> Option<usize> {
181 self.highlight_regions.iter().find_map(|h| match h {
182 Some((r, n)) if r == region => Some(*n),
183 _ => None,
184 })
185 }
186
187 /// Highlight the given bound region.
188 /// We can only highlight one bound region at a time. See
189 /// the field `highlight_bound_region` for more detailed notes.
highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize)190 pub fn highlighting_bound_region(&mut self, br: ty::BoundRegionKind, number: usize) {
191 assert!(self.highlight_bound_region.is_none());
192 self.highlight_bound_region = Some((br, number));
193 }
194 }
195
196 /// Trait for printers that pretty-print using `fmt::Write` to the printer.
197 pub trait PrettyPrinter<'tcx>:
198 Printer<
199 'tcx,
200 Error = fmt::Error,
201 Path = Self,
202 Region = Self,
203 Type = Self,
204 DynExistential = Self,
205 Const = Self,
206 > + fmt::Write
207 {
208 /// Like `print_def_path` but for value paths.
print_value_path( self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>209 fn print_value_path(
210 self,
211 def_id: DefId,
212 substs: &'tcx [GenericArg<'tcx>],
213 ) -> Result<Self::Path, Self::Error> {
214 self.print_def_path(def_id, substs)
215 }
216
in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,217 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
218 where
219 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
220 {
221 value.as_ref().skip_binder().print(self)
222 }
223
wrap_binder<T, F: Fn(&T, Self) -> Result<Self, fmt::Error>>( self, value: &ty::Binder<'tcx, T>, f: F, ) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,224 fn wrap_binder<T, F: Fn(&T, Self) -> Result<Self, fmt::Error>>(
225 self,
226 value: &ty::Binder<'tcx, T>,
227 f: F,
228 ) -> Result<Self, Self::Error>
229 where
230 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
231 {
232 f(value.as_ref().skip_binder(), self)
233 }
234
235 /// 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>,236 fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
237 where
238 T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
239 {
240 if let Some(first) = elems.next() {
241 self = first.print(self)?;
242 for elem in elems {
243 self.write_str(", ")?;
244 self = elem.print(self)?;
245 }
246 }
247 Ok(self)
248 }
249
250 /// 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>251 fn typed_value(
252 mut self,
253 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
254 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
255 conversion: &str,
256 ) -> Result<Self::Const, Self::Error> {
257 self.write_str("{")?;
258 self = f(self)?;
259 self.write_str(conversion)?;
260 self = t(self)?;
261 self.write_str("}")?;
262 Ok(self)
263 }
264
265 /// Prints `<...>` around what `f` prints.
generic_delimiters( self, f: impl FnOnce(Self) -> Result<Self, Self::Error>, ) -> Result<Self, Self::Error>266 fn generic_delimiters(
267 self,
268 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
269 ) -> Result<Self, Self::Error>;
270
271 /// Returns `true` if the region should be printed in
272 /// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
273 /// This is typically the case for all non-`'_` regions.
region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool274 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool;
275
276 // Defaults (should not be overridden):
277
278 /// If possible, this returns a global path resolving to `def_id` that is visible
279 /// from at least one local module, and returns `true`. If the crate defining `def_id` is
280 /// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error>281 fn try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
282 if NO_VISIBLE_PATH.with(|flag| flag.get()) {
283 return Ok((self, false));
284 }
285
286 let mut callers = Vec::new();
287 self.try_print_visible_def_path_recur(def_id, &mut callers)
288 }
289
290 /// 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>291 fn try_print_trimmed_def_path(
292 mut self,
293 def_id: DefId,
294 ) -> Result<(Self::Path, bool), Self::Error> {
295 if !self.tcx().sess.opts.debugging_opts.trim_diagnostic_paths
296 || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never)
297 || NO_TRIMMED_PATH.with(|flag| flag.get())
298 || SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get())
299 {
300 return Ok((self, false));
301 }
302
303 match self.tcx().trimmed_def_paths(()).get(&def_id) {
304 None => Ok((self, false)),
305 Some(symbol) => {
306 self.write_str(&symbol.as_str())?;
307 Ok((self, true))
308 }
309 }
310 }
311
312 /// Does the work of `try_print_visible_def_path`, building the
313 /// full definition path recursively before attempting to
314 /// post-process it into the valid and visible version that
315 /// accounts for re-exports.
316 ///
317 /// This method should only be called by itself or
318 /// `try_print_visible_def_path`.
319 ///
320 /// `callers` is a chain of visible_parent's leading to `def_id`,
321 /// to support cycle detection during recursion.
try_print_visible_def_path_recur( mut self, def_id: DefId, callers: &mut Vec<DefId>, ) -> Result<(Self, bool), Self::Error>322 fn try_print_visible_def_path_recur(
323 mut self,
324 def_id: DefId,
325 callers: &mut Vec<DefId>,
326 ) -> Result<(Self, bool), Self::Error> {
327 define_scoped_cx!(self);
328
329 debug!("try_print_visible_def_path: def_id={:?}", def_id);
330
331 // If `def_id` is a direct or injected extern crate, return the
332 // path to the crate followed by the path to the item within the crate.
333 if def_id.index == CRATE_DEF_INDEX {
334 let cnum = def_id.krate;
335
336 if cnum == LOCAL_CRATE {
337 return Ok((self.path_crate(cnum)?, true));
338 }
339
340 // In local mode, when we encounter a crate other than
341 // LOCAL_CRATE, execution proceeds in one of two ways:
342 //
343 // 1. For a direct dependency, where user added an
344 // `extern crate` manually, we put the `extern
345 // crate` as the parent. So you wind up with
346 // something relative to the current crate.
347 // 2. For an extern inferred from a path or an indirect crate,
348 // where there is no explicit `extern crate`, we just prepend
349 // the crate name.
350 match self.tcx().extern_crate(def_id) {
351 Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
352 (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
353 // NOTE(eddyb) the only reason `span` might be dummy,
354 // that we're aware of, is that it's the `std`/`core`
355 // `extern crate` injected by default.
356 // FIXME(eddyb) find something better to key this on,
357 // or avoid ending up with `ExternCrateSource::Extern`,
358 // for the injected `std`/`core`.
359 if span.is_dummy() {
360 return Ok((self.path_crate(cnum)?, true));
361 }
362
363 // Disable `try_print_trimmed_def_path` behavior within
364 // the `print_def_path` call, to avoid infinite recursion
365 // in cases where the `extern crate foo` has non-trivial
366 // parents, e.g. it's nested in `impl foo::Trait for Bar`
367 // (see also issues #55779 and #87932).
368 self = with_no_visible_paths(|| self.print_def_path(def_id, &[]))?;
369
370 return Ok((self, true));
371 }
372 (ExternCrateSource::Path, LOCAL_CRATE) => {
373 return Ok((self.path_crate(cnum)?, true));
374 }
375 _ => {}
376 },
377 None => {
378 return Ok((self.path_crate(cnum)?, true));
379 }
380 }
381 }
382
383 if def_id.is_local() {
384 return Ok((self, false));
385 }
386
387 let visible_parent_map = self.tcx().visible_parent_map(());
388
389 let mut cur_def_key = self.tcx().def_key(def_id);
390 debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
391
392 // For a constructor, we want the name of its parent rather than <unnamed>.
393 if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
394 let parent = DefId {
395 krate: def_id.krate,
396 index: cur_def_key
397 .parent
398 .expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
399 };
400
401 cur_def_key = self.tcx().def_key(parent);
402 }
403
404 let visible_parent = match visible_parent_map.get(&def_id).cloned() {
405 Some(parent) => parent,
406 None => return Ok((self, false)),
407 };
408 if callers.contains(&visible_parent) {
409 return Ok((self, false));
410 }
411 callers.push(visible_parent);
412 // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
413 // knowing ahead of time whether the entire path will succeed or not.
414 // To support printers that do not implement `PrettyPrinter`, a `Vec` or
415 // linked list on the stack would need to be built, before any printing.
416 match self.try_print_visible_def_path_recur(visible_parent, callers)? {
417 (cx, false) => return Ok((cx, false)),
418 (cx, true) => self = cx,
419 }
420 callers.pop();
421 let actual_parent = self.tcx().parent(def_id);
422 debug!(
423 "try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
424 visible_parent, actual_parent,
425 );
426
427 let mut data = cur_def_key.disambiguated_data.data;
428 debug!(
429 "try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
430 data, visible_parent, actual_parent,
431 );
432
433 match data {
434 // In order to output a path that could actually be imported (valid and visible),
435 // we need to handle re-exports correctly.
436 //
437 // For example, take `std::os::unix::process::CommandExt`, this trait is actually
438 // defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
439 //
440 // `std::os::unix` rexports the contents of `std::sys::unix::ext`. `std::sys` is
441 // private so the "true" path to `CommandExt` isn't accessible.
442 //
443 // In this case, the `visible_parent_map` will look something like this:
444 //
445 // (child) -> (parent)
446 // `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
447 // `std::sys::unix::ext::process` -> `std::sys::unix::ext`
448 // `std::sys::unix::ext` -> `std::os`
449 //
450 // This is correct, as the visible parent of `std::sys::unix::ext` is in fact
451 // `std::os`.
452 //
453 // When printing the path to `CommandExt` and looking at the `cur_def_key` that
454 // corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
455 // to the parent - resulting in a mangled path like
456 // `std::os::ext::process::CommandExt`.
457 //
458 // Instead, we must detect that there was a re-export and instead print `unix`
459 // (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
460 // do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
461 // the visible parent (`std::os`). If these do not match, then we iterate over
462 // the children of the visible parent (as was done when computing
463 // `visible_parent_map`), looking for the specific child we currently have and then
464 // have access to the re-exported name.
465 DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
466 let reexport = self
467 .tcx()
468 .item_children(visible_parent)
469 .iter()
470 .find(|child| child.res.opt_def_id() == Some(def_id))
471 .map(|child| child.ident.name);
472 if let Some(reexport) = reexport {
473 *name = reexport;
474 }
475 }
476 // Re-exported `extern crate` (#43189).
477 DefPathData::CrateRoot => {
478 data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
479 }
480 _ => {}
481 }
482 debug!("try_print_visible_def_path: data={:?}", data);
483
484 Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
485 }
486
pretty_path_qualified( self, self_ty: Ty<'tcx>, trait_ref: Option<ty::TraitRef<'tcx>>, ) -> Result<Self::Path, Self::Error>487 fn pretty_path_qualified(
488 self,
489 self_ty: Ty<'tcx>,
490 trait_ref: Option<ty::TraitRef<'tcx>>,
491 ) -> Result<Self::Path, Self::Error> {
492 if trait_ref.is_none() {
493 // Inherent impls. Try to print `Foo::bar` for an inherent
494 // impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
495 // anything other than a simple path.
496 match self_ty.kind() {
497 ty::Adt(..)
498 | ty::Foreign(_)
499 | ty::Bool
500 | ty::Char
501 | ty::Str
502 | ty::Int(_)
503 | ty::Uint(_)
504 | ty::Float(_) => {
505 return self_ty.print(self);
506 }
507
508 _ => {}
509 }
510 }
511
512 self.generic_delimiters(|mut cx| {
513 define_scoped_cx!(cx);
514
515 p!(print(self_ty));
516 if let Some(trait_ref) = trait_ref {
517 p!(" as ", print(trait_ref.print_only_trait_path()));
518 }
519 Ok(cx)
520 })
521 }
522
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>523 fn pretty_path_append_impl(
524 mut self,
525 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
526 self_ty: Ty<'tcx>,
527 trait_ref: Option<ty::TraitRef<'tcx>>,
528 ) -> Result<Self::Path, Self::Error> {
529 self = print_prefix(self)?;
530
531 self.generic_delimiters(|mut cx| {
532 define_scoped_cx!(cx);
533
534 p!("impl ");
535 if let Some(trait_ref) = trait_ref {
536 p!(print(trait_ref.print_only_trait_path()), " for ");
537 }
538 p!(print(self_ty));
539
540 Ok(cx)
541 })
542 }
543
pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error>544 fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
545 define_scoped_cx!(self);
546
547 match *ty.kind() {
548 ty::Bool => p!("bool"),
549 ty::Char => p!("char"),
550 ty::Int(t) => p!(write("{}", t.name_str())),
551 ty::Uint(t) => p!(write("{}", t.name_str())),
552 ty::Float(t) => p!(write("{}", t.name_str())),
553 ty::RawPtr(ref tm) => {
554 p!(write(
555 "*{} ",
556 match tm.mutbl {
557 hir::Mutability::Mut => "mut",
558 hir::Mutability::Not => "const",
559 }
560 ));
561 p!(print(tm.ty))
562 }
563 ty::Ref(r, ty, mutbl) => {
564 p!("&");
565 if self.region_should_not_be_omitted(r) {
566 p!(print(r), " ");
567 }
568 p!(print(ty::TypeAndMut { ty, mutbl }))
569 }
570 ty::Never => p!("!"),
571 ty::Tuple(ref tys) => {
572 p!("(", comma_sep(tys.iter()));
573 if tys.len() == 1 {
574 p!(",");
575 }
576 p!(")")
577 }
578 ty::FnDef(def_id, substs) => {
579 let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
580 p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
581 }
582 ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
583 ty::Infer(infer_ty) => {
584 let verbose = self.tcx().sess.verbose();
585 if let ty::TyVar(ty_vid) = infer_ty {
586 if let Some(name) = self.infer_ty_name(ty_vid) {
587 p!(write("{}", name))
588 } else {
589 if verbose {
590 p!(write("{:?}", infer_ty))
591 } else {
592 p!(write("{}", infer_ty))
593 }
594 }
595 } else {
596 if verbose { p!(write("{:?}", infer_ty)) } else { p!(write("{}", infer_ty)) }
597 }
598 }
599 ty::Error(_) => p!("[type error]"),
600 ty::Param(ref param_ty) => p!(write("{}", param_ty)),
601 ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
602 ty::BoundTyKind::Anon => self.pretty_print_bound_var(debruijn, bound_ty.var)?,
603 ty::BoundTyKind::Param(p) => p!(write("{}", p)),
604 },
605 ty::Adt(def, substs) => {
606 p!(print_def_path(def.did, substs));
607 }
608 ty::Dynamic(data, r) => {
609 let print_r = self.region_should_not_be_omitted(r);
610 if print_r {
611 p!("(");
612 }
613 p!("dyn ", print(data));
614 if print_r {
615 p!(" + ", print(r), ")");
616 }
617 }
618 ty::Foreign(def_id) => {
619 p!(print_def_path(def_id, &[]));
620 }
621 ty::Projection(ref data) => p!(print(data)),
622 ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
623 ty::Opaque(def_id, substs) => {
624 // FIXME(eddyb) print this with `print_def_path`.
625 // We use verbose printing in 'NO_QUERIES' mode, to
626 // avoid needing to call `predicates_of`. This should
627 // only affect certain debug messages (e.g. messages printed
628 // from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
629 // and should have no effect on any compiler output.
630 if self.tcx().sess.verbose() || NO_QUERIES.with(|q| q.get()) {
631 p!(write("Opaque({:?}, {:?})", def_id, substs));
632 return Ok(self);
633 }
634
635 return with_no_queries(|| {
636 let def_key = self.tcx().def_key(def_id);
637 if let Some(name) = def_key.disambiguated_data.data.get_opt_name() {
638 p!(write("{}", name));
639 // FIXME(eddyb) print this with `print_def_path`.
640 if !substs.is_empty() {
641 p!("::");
642 p!(generic_delimiters(|cx| cx.comma_sep(substs.iter())));
643 }
644 return Ok(self);
645 }
646
647 self.pretty_print_opaque_impl_type(def_id, substs)
648 });
649 }
650 ty::Str => p!("str"),
651 ty::Generator(did, substs, movability) => {
652 p!(write("["));
653 match movability {
654 hir::Movability::Movable => {}
655 hir::Movability::Static => p!("static "),
656 }
657
658 if !self.tcx().sess.verbose() {
659 p!("generator");
660 // FIXME(eddyb) should use `def_span`.
661 if let Some(did) = did.as_local() {
662 let hir_id = self.tcx().hir().local_def_id_to_hir_id(did);
663 let span = self.tcx().hir().span(hir_id);
664 p!(write(
665 "@{}",
666 // This may end up in stderr diagnostics but it may also be emitted
667 // into MIR. Hence we use the remapped path if available
668 self.tcx().sess.source_map().span_to_embeddable_string(span)
669 ));
670 } else {
671 p!(write("@"), print_def_path(did, substs));
672 }
673 } else {
674 p!(print_def_path(did, substs));
675 p!(" upvar_tys=(");
676 if !substs.as_generator().is_valid() {
677 p!("unavailable");
678 } else {
679 self = self.comma_sep(substs.as_generator().upvar_tys())?;
680 }
681 p!(")");
682
683 if substs.as_generator().is_valid() {
684 p!(" ", print(substs.as_generator().witness()));
685 }
686 }
687
688 p!("]")
689 }
690 ty::GeneratorWitness(types) => {
691 p!(in_binder(&types));
692 }
693 ty::Closure(did, substs) => {
694 p!(write("["));
695 if !self.tcx().sess.verbose() {
696 p!(write("closure"));
697 // FIXME(eddyb) should use `def_span`.
698 if let Some(did) = did.as_local() {
699 let hir_id = self.tcx().hir().local_def_id_to_hir_id(did);
700 if self.tcx().sess.opts.debugging_opts.span_free_formats {
701 p!("@", print_def_path(did.to_def_id(), substs));
702 } else {
703 let span = self.tcx().hir().span(hir_id);
704 p!(write(
705 "@{}",
706 // This may end up in stderr diagnostics but it may also be emitted
707 // into MIR. Hence we use the remapped path if available
708 self.tcx().sess.source_map().span_to_embeddable_string(span)
709 ));
710 }
711 } else {
712 p!(write("@"), print_def_path(did, substs));
713 }
714 } else {
715 p!(print_def_path(did, substs));
716 if !substs.as_closure().is_valid() {
717 p!(" closure_substs=(unavailable)");
718 p!(write(" substs={:?}", substs));
719 } else {
720 p!(" closure_kind_ty=", print(substs.as_closure().kind_ty()));
721 p!(
722 " closure_sig_as_fn_ptr_ty=",
723 print(substs.as_closure().sig_as_fn_ptr_ty())
724 );
725 p!(" upvar_tys=(");
726 self = self.comma_sep(substs.as_closure().upvar_tys())?;
727 p!(")");
728 }
729 }
730 p!("]");
731 }
732 ty::Array(ty, sz) => {
733 p!("[", print(ty), "; ");
734 if self.tcx().sess.verbose() {
735 p!(write("{:?}", sz));
736 } else if let ty::ConstKind::Unevaluated(..) = sz.val {
737 // Do not try to evaluate unevaluated constants. If we are const evaluating an
738 // array length anon const, rustc will (with debug assertions) print the
739 // constant's path. Which will end up here again.
740 p!("_");
741 } else if let Some(n) = sz.val.try_to_bits(self.tcx().data_layout.pointer_size) {
742 p!(write("{}", n));
743 } else if let ty::ConstKind::Param(param) = sz.val {
744 p!(write("{}", param));
745 } else {
746 p!("_");
747 }
748 p!("]")
749 }
750 ty::Slice(ty) => p!("[", print(ty), "]"),
751 }
752
753 Ok(self)
754 }
755
pretty_print_opaque_impl_type( mut self, def_id: DefId, substs: &'tcx ty::List<ty::GenericArg<'tcx>>, ) -> Result<Self::Type, Self::Error>756 fn pretty_print_opaque_impl_type(
757 mut self,
758 def_id: DefId,
759 substs: &'tcx ty::List<ty::GenericArg<'tcx>>,
760 ) -> Result<Self::Type, Self::Error> {
761 define_scoped_cx!(self);
762
763 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
764 // by looking up the projections associated with the def_id.
765 let bounds = self.tcx().explicit_item_bounds(def_id);
766
767 let mut traits = BTreeMap::new();
768 let mut fn_traits = BTreeMap::new();
769 let mut is_sized = false;
770
771 for (predicate, _) in bounds {
772 let predicate = predicate.subst(self.tcx(), substs);
773 let bound_predicate = predicate.kind();
774
775 match bound_predicate.skip_binder() {
776 ty::PredicateKind::Trait(pred) => {
777 let trait_ref = bound_predicate.rebind(pred.trait_ref);
778
779 // Don't print + Sized, but rather + ?Sized if absent.
780 if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
781 is_sized = true;
782 continue;
783 }
784
785 self.insert_trait_and_projection(trait_ref, None, &mut traits, &mut fn_traits);
786 }
787 ty::PredicateKind::Projection(pred) => {
788 let proj_ref = bound_predicate.rebind(pred);
789 let trait_ref = proj_ref.required_poly_trait_ref(self.tcx());
790
791 // Projection type entry -- the def-id for naming, and the ty.
792 let proj_ty = (proj_ref.projection_def_id(), proj_ref.ty());
793
794 self.insert_trait_and_projection(
795 trait_ref,
796 Some(proj_ty),
797 &mut traits,
798 &mut fn_traits,
799 );
800 }
801 _ => {}
802 }
803 }
804
805 let mut first = true;
806 // Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
807 let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !is_sized;
808
809 p!("impl");
810
811 for (fn_once_trait_ref, entry) in fn_traits {
812 // Get the (single) generic ty (the args) of this FnOnce trait ref.
813 let generics = self.generic_args_to_print(
814 self.tcx().generics_of(fn_once_trait_ref.def_id()),
815 fn_once_trait_ref.skip_binder().substs,
816 );
817
818 match (entry.return_ty, generics[0].expect_ty()) {
819 // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
820 // a return type.
821 (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
822 let name = if entry.fn_trait_ref.is_some() {
823 "Fn"
824 } else if entry.fn_mut_trait_ref.is_some() {
825 "FnMut"
826 } else {
827 "FnOnce"
828 };
829
830 p!(
831 write("{}", if first { " " } else { " + " }),
832 write("{}{}(", if paren_needed { "(" } else { "" }, name)
833 );
834
835 for (idx, ty) in arg_tys.tuple_fields().enumerate() {
836 if idx > 0 {
837 p!(", ");
838 }
839 p!(print(ty));
840 }
841
842 p!(")");
843 if !return_ty.skip_binder().is_unit() {
844 p!("-> ", print(return_ty));
845 }
846 p!(write("{}", if paren_needed { ")" } else { "" }));
847
848 first = false;
849 }
850 // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
851 // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
852 _ => {
853 if entry.has_fn_once {
854 traits.entry(fn_once_trait_ref).or_default().extend(
855 // Group the return ty with its def id, if we had one.
856 entry
857 .return_ty
858 .map(|ty| (self.tcx().lang_items().fn_once_output().unwrap(), ty)),
859 );
860 }
861 if let Some(trait_ref) = entry.fn_mut_trait_ref {
862 traits.entry(trait_ref).or_default();
863 }
864 if let Some(trait_ref) = entry.fn_trait_ref {
865 traits.entry(trait_ref).or_default();
866 }
867 }
868 }
869 }
870
871 // Print the rest of the trait types (that aren't Fn* family of traits)
872 for (trait_ref, assoc_items) in traits {
873 p!(
874 write("{}", if first { " " } else { " + " }),
875 print(trait_ref.skip_binder().print_only_trait_name())
876 );
877
878 let generics = self.generic_args_to_print(
879 self.tcx().generics_of(trait_ref.def_id()),
880 trait_ref.skip_binder().substs,
881 );
882
883 if !generics.is_empty() || !assoc_items.is_empty() {
884 p!("<");
885 let mut first = true;
886
887 for ty in generics {
888 if !first {
889 p!(", ");
890 }
891 p!(print(trait_ref.rebind(*ty)));
892 first = false;
893 }
894
895 for (assoc_item_def_id, ty) in assoc_items {
896 if !first {
897 p!(", ");
898 }
899 p!(write("{} = ", self.tcx().associated_item(assoc_item_def_id).ident));
900
901 // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks
902 match ty.skip_binder().kind() {
903 ty::Projection(ty::ProjectionTy { item_def_id, .. })
904 if Some(*item_def_id) == self.tcx().lang_items().generator_return() =>
905 {
906 p!("[async output]")
907 }
908 _ => {
909 p!(print(ty))
910 }
911 }
912
913 first = false;
914 }
915
916 p!(">");
917 }
918
919 first = false;
920 }
921
922 if !is_sized {
923 p!(write("{}?Sized", if first { " " } else { " + " }));
924 } else if first {
925 p!(" Sized");
926 }
927
928 Ok(self)
929 }
930
931 /// Insert the trait ref and optionally a projection type associated with it into either the
932 /// 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, Ty<'tcx>>)>, traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, BTreeMap<DefId, ty::Binder<'tcx, Ty<'tcx>>>>, fn_traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, OpaqueFnEntry<'tcx>>, )933 fn insert_trait_and_projection(
934 &mut self,
935 trait_ref: ty::PolyTraitRef<'tcx>,
936 proj_ty: Option<(DefId, ty::Binder<'tcx, Ty<'tcx>>)>,
937 traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, BTreeMap<DefId, ty::Binder<'tcx, Ty<'tcx>>>>,
938 fn_traits: &mut BTreeMap<ty::PolyTraitRef<'tcx>, OpaqueFnEntry<'tcx>>,
939 ) {
940 let trait_def_id = trait_ref.def_id();
941
942 // If our trait_ref is FnOnce or any of its children, project it onto the parent FnOnce
943 // super-trait ref and record it there.
944 if let Some(fn_once_trait) = self.tcx().lang_items().fn_once_trait() {
945 // If we have a FnOnce, then insert it into
946 if trait_def_id == fn_once_trait {
947 let entry = fn_traits.entry(trait_ref).or_default();
948 // Optionally insert the return_ty as well.
949 if let Some((_, ty)) = proj_ty {
950 entry.return_ty = Some(ty);
951 }
952 entry.has_fn_once = true;
953 return;
954 } else if Some(trait_def_id) == self.tcx().lang_items().fn_mut_trait() {
955 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
956 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
957 .unwrap();
958
959 fn_traits.entry(super_trait_ref).or_default().fn_mut_trait_ref = Some(trait_ref);
960 return;
961 } else if Some(trait_def_id) == self.tcx().lang_items().fn_trait() {
962 let super_trait_ref = crate::traits::util::supertraits(self.tcx(), trait_ref)
963 .find(|super_trait_ref| super_trait_ref.def_id() == fn_once_trait)
964 .unwrap();
965
966 fn_traits.entry(super_trait_ref).or_default().fn_trait_ref = Some(trait_ref);
967 return;
968 }
969 }
970
971 // Otherwise, just group our traits and projection types.
972 traits.entry(trait_ref).or_default().extend(proj_ty);
973 }
974
pretty_print_bound_var( &mut self, debruijn: ty::DebruijnIndex, var: ty::BoundVar, ) -> Result<(), Self::Error>975 fn pretty_print_bound_var(
976 &mut self,
977 debruijn: ty::DebruijnIndex,
978 var: ty::BoundVar,
979 ) -> Result<(), Self::Error> {
980 if debruijn == ty::INNERMOST {
981 write!(self, "^{}", var.index())
982 } else {
983 write!(self, "^{}_{}", debruijn.index(), var.index())
984 }
985 }
986
infer_ty_name(&self, _: ty::TyVid) -> Option<String>987 fn infer_ty_name(&self, _: ty::TyVid) -> Option<String> {
988 None
989 }
990
pretty_print_dyn_existential( mut self, predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>, ) -> Result<Self::DynExistential, Self::Error>991 fn pretty_print_dyn_existential(
992 mut self,
993 predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
994 ) -> Result<Self::DynExistential, Self::Error> {
995 // Generate the main trait ref, including associated types.
996 let mut first = true;
997
998 if let Some(principal) = predicates.principal() {
999 self = self.wrap_binder(&principal, |principal, mut cx| {
1000 define_scoped_cx!(cx);
1001 p!(print_def_path(principal.def_id, &[]));
1002
1003 let mut resugared = false;
1004
1005 // Special-case `Fn(...) -> ...` and resugar it.
1006 let fn_trait_kind = cx.tcx().fn_trait_kind_from_lang_item(principal.def_id);
1007 if !cx.tcx().sess.verbose() && fn_trait_kind.is_some() {
1008 if let ty::Tuple(ref args) = principal.substs.type_at(0).kind() {
1009 let mut projections = predicates.projection_bounds();
1010 if let (Some(proj), None) = (projections.next(), projections.next()) {
1011 let tys: Vec<_> = args.iter().map(|k| k.expect_ty()).collect();
1012 p!(pretty_fn_sig(&tys, false, proj.skip_binder().ty));
1013 resugared = true;
1014 }
1015 }
1016 }
1017
1018 // HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
1019 // in order to place the projections inside the `<...>`.
1020 if !resugared {
1021 // Use a type that can't appear in defaults of type parameters.
1022 let dummy_cx = cx.tcx().mk_ty_infer(ty::FreshTy(0));
1023 let principal = principal.with_self_ty(cx.tcx(), dummy_cx);
1024
1025 let args = cx.generic_args_to_print(
1026 cx.tcx().generics_of(principal.def_id),
1027 principal.substs,
1028 );
1029
1030 // Don't print `'_` if there's no unerased regions.
1031 let print_regions = args.iter().any(|arg| match arg.unpack() {
1032 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
1033 _ => false,
1034 });
1035 let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
1036 GenericArgKind::Lifetime(_) => print_regions,
1037 _ => true,
1038 });
1039 let mut projections = predicates.projection_bounds();
1040
1041 let arg0 = args.next();
1042 let projection0 = projections.next();
1043 if arg0.is_some() || projection0.is_some() {
1044 let args = arg0.into_iter().chain(args);
1045 let projections = projection0.into_iter().chain(projections);
1046
1047 p!(generic_delimiters(|mut cx| {
1048 cx = cx.comma_sep(args)?;
1049 if arg0.is_some() && projection0.is_some() {
1050 write!(cx, ", ")?;
1051 }
1052 cx.comma_sep(projections)
1053 }));
1054 }
1055 }
1056 Ok(cx)
1057 })?;
1058
1059 first = false;
1060 }
1061
1062 define_scoped_cx!(self);
1063
1064 // Builtin bounds.
1065 // FIXME(eddyb) avoid printing twice (needed to ensure
1066 // that the auto traits are sorted *and* printed via cx).
1067 let mut auto_traits: Vec<_> =
1068 predicates.auto_traits().map(|did| (self.tcx().def_path_str(did), did)).collect();
1069
1070 // The auto traits come ordered by `DefPathHash`. While
1071 // `DefPathHash` is *stable* in the sense that it depends on
1072 // neither the host nor the phase of the moon, it depends
1073 // "pseudorandomly" on the compiler version and the target.
1074 //
1075 // To avoid that causing instabilities in compiletest
1076 // output, sort the auto-traits alphabetically.
1077 auto_traits.sort();
1078
1079 for (_, def_id) in auto_traits {
1080 if !first {
1081 p!(" + ");
1082 }
1083 first = false;
1084
1085 p!(print_def_path(def_id, &[]));
1086 }
1087
1088 Ok(self)
1089 }
1090
pretty_fn_sig( mut self, inputs: &[Ty<'tcx>], c_variadic: bool, output: Ty<'tcx>, ) -> Result<Self, Self::Error>1091 fn pretty_fn_sig(
1092 mut self,
1093 inputs: &[Ty<'tcx>],
1094 c_variadic: bool,
1095 output: Ty<'tcx>,
1096 ) -> Result<Self, Self::Error> {
1097 define_scoped_cx!(self);
1098
1099 p!("(", comma_sep(inputs.iter().copied()));
1100 if c_variadic {
1101 if !inputs.is_empty() {
1102 p!(", ");
1103 }
1104 p!("...");
1105 }
1106 p!(")");
1107 if !output.is_unit() {
1108 p!(" -> ", print(output));
1109 }
1110
1111 Ok(self)
1112 }
1113
pretty_print_const( mut self, ct: &'tcx ty::Const<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1114 fn pretty_print_const(
1115 mut self,
1116 ct: &'tcx ty::Const<'tcx>,
1117 print_ty: bool,
1118 ) -> Result<Self::Const, Self::Error> {
1119 define_scoped_cx!(self);
1120
1121 if self.tcx().sess.verbose() {
1122 p!(write("Const({:?}: {:?})", ct.val, ct.ty));
1123 return Ok(self);
1124 }
1125
1126 macro_rules! print_underscore {
1127 () => {{
1128 if print_ty {
1129 self = self.typed_value(
1130 |mut this| {
1131 write!(this, "_")?;
1132 Ok(this)
1133 },
1134 |this| this.print_type(ct.ty),
1135 ": ",
1136 )?;
1137 } else {
1138 write!(self, "_")?;
1139 }
1140 }};
1141 }
1142
1143 match ct.val {
1144 ty::ConstKind::Unevaluated(uv) => {
1145 if let Some(promoted) = uv.promoted {
1146 let substs = uv.substs_.unwrap();
1147 p!(print_value_path(uv.def.did, substs));
1148 p!(write("::{:?}", promoted));
1149 } else {
1150 let tcx = self.tcx();
1151 match tcx.def_kind(uv.def.did) {
1152 DefKind::Static | DefKind::Const | DefKind::AssocConst => {
1153 p!(print_value_path(uv.def.did, uv.substs(tcx)))
1154 }
1155 _ => {
1156 if uv.def.is_local() {
1157 let span = tcx.def_span(uv.def.did);
1158 if let Ok(snip) = tcx.sess.source_map().span_to_snippet(span) {
1159 p!(write("{}", snip))
1160 } else {
1161 print_underscore!()
1162 }
1163 } else {
1164 print_underscore!()
1165 }
1166 }
1167 }
1168 }
1169 }
1170 ty::ConstKind::Infer(..) => print_underscore!(),
1171 ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
1172 ty::ConstKind::Value(value) => {
1173 return self.pretty_print_const_value(value, ct.ty, print_ty);
1174 }
1175
1176 ty::ConstKind::Bound(debruijn, bound_var) => {
1177 self.pretty_print_bound_var(debruijn, bound_var)?
1178 }
1179 ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
1180 ty::ConstKind::Error(_) => p!("[const error]"),
1181 };
1182 Ok(self)
1183 }
1184
pretty_print_const_scalar( self, scalar: Scalar, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1185 fn pretty_print_const_scalar(
1186 self,
1187 scalar: Scalar,
1188 ty: Ty<'tcx>,
1189 print_ty: bool,
1190 ) -> Result<Self::Const, Self::Error> {
1191 match scalar {
1192 Scalar::Ptr(ptr, _size) => self.pretty_print_const_scalar_ptr(ptr, ty, print_ty),
1193 Scalar::Int(int) => self.pretty_print_const_scalar_int(int, ty, print_ty),
1194 }
1195 }
1196
pretty_print_const_scalar_ptr( mut self, ptr: Pointer, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1197 fn pretty_print_const_scalar_ptr(
1198 mut self,
1199 ptr: Pointer,
1200 ty: Ty<'tcx>,
1201 print_ty: bool,
1202 ) -> Result<Self::Const, Self::Error> {
1203 define_scoped_cx!(self);
1204
1205 let (alloc_id, offset) = ptr.into_parts();
1206 match ty.kind() {
1207 // Byte strings (&[u8; N])
1208 ty::Ref(
1209 _,
1210 ty::TyS {
1211 kind:
1212 ty::Array(
1213 ty::TyS { kind: ty::Uint(ty::UintTy::U8), .. },
1214 ty::Const {
1215 val: ty::ConstKind::Value(ConstValue::Scalar(int)), ..
1216 },
1217 ),
1218 ..
1219 },
1220 _,
1221 ) => match self.tcx().get_global_alloc(alloc_id) {
1222 Some(GlobalAlloc::Memory(alloc)) => {
1223 let len = int.assert_bits(self.tcx().data_layout.pointer_size);
1224 let range = AllocRange { start: offset, size: Size::from_bytes(len) };
1225 if let Ok(byte_str) = alloc.get_bytes(&self.tcx(), range) {
1226 p!(pretty_print_byte_str(byte_str))
1227 } else {
1228 p!("<too short allocation>")
1229 }
1230 }
1231 // FIXME: for statics and functions, we could in principle print more detail.
1232 Some(GlobalAlloc::Static(def_id)) => p!(write("<static({:?})>", def_id)),
1233 Some(GlobalAlloc::Function(_)) => p!("<function>"),
1234 None => p!("<dangling pointer>"),
1235 },
1236 ty::FnPtr(_) => {
1237 // FIXME: We should probably have a helper method to share code with the "Byte strings"
1238 // printing above (which also has to handle pointers to all sorts of things).
1239 match self.tcx().get_global_alloc(alloc_id) {
1240 Some(GlobalAlloc::Function(instance)) => {
1241 self = self.typed_value(
1242 |this| this.print_value_path(instance.def_id(), instance.substs),
1243 |this| this.print_type(ty),
1244 " as ",
1245 )?;
1246 }
1247 _ => self = self.pretty_print_const_pointer(ptr, ty, print_ty)?,
1248 }
1249 }
1250 // Any pointer values not covered by a branch above
1251 _ => {
1252 self = self.pretty_print_const_pointer(ptr, ty, print_ty)?;
1253 }
1254 }
1255 Ok(self)
1256 }
1257
pretty_print_const_scalar_int( mut self, int: ScalarInt, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1258 fn pretty_print_const_scalar_int(
1259 mut self,
1260 int: ScalarInt,
1261 ty: Ty<'tcx>,
1262 print_ty: bool,
1263 ) -> Result<Self::Const, Self::Error> {
1264 define_scoped_cx!(self);
1265
1266 match ty.kind() {
1267 // Bool
1268 ty::Bool if int == ScalarInt::FALSE => p!("false"),
1269 ty::Bool if int == ScalarInt::TRUE => p!("true"),
1270 // Float
1271 ty::Float(ty::FloatTy::F32) => {
1272 p!(write("{}f32", Single::try_from(int).unwrap()))
1273 }
1274 ty::Float(ty::FloatTy::F64) => {
1275 p!(write("{}f64", Double::try_from(int).unwrap()))
1276 }
1277 // Int
1278 ty::Uint(_) | ty::Int(_) => {
1279 let int =
1280 ConstInt::new(int, matches!(ty.kind(), ty::Int(_)), ty.is_ptr_sized_integral());
1281 if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
1282 }
1283 // Char
1284 ty::Char if char::try_from(int).is_ok() => {
1285 p!(write("{:?}", char::try_from(int).unwrap()))
1286 }
1287 // Pointer types
1288 ty::Ref(..) | ty::RawPtr(_) | ty::FnPtr(_) => {
1289 let data = int.assert_bits(self.tcx().data_layout.pointer_size);
1290 self = self.typed_value(
1291 |mut this| {
1292 write!(this, "0x{:x}", data)?;
1293 Ok(this)
1294 },
1295 |this| this.print_type(ty),
1296 " as ",
1297 )?;
1298 }
1299 // For function type zsts just printing the path is enough
1300 ty::FnDef(d, s) if int == ScalarInt::ZST => {
1301 p!(print_value_path(*d, s))
1302 }
1303 // Nontrivial types with scalar bit representation
1304 _ => {
1305 let print = |mut this: Self| {
1306 if int.size() == Size::ZERO {
1307 write!(this, "transmute(())")?;
1308 } else {
1309 write!(this, "transmute(0x{:x})", int)?;
1310 }
1311 Ok(this)
1312 };
1313 self = if print_ty {
1314 self.typed_value(print, |this| this.print_type(ty), ": ")?
1315 } else {
1316 print(self)?
1317 };
1318 }
1319 }
1320 Ok(self)
1321 }
1322
1323 /// This is overridden for MIR printing because we only want to hide alloc ids from users, not
1324 /// from MIR where it is actually useful.
pretty_print_const_pointer<Tag: Provenance>( mut self, _: Pointer<Tag>, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1325 fn pretty_print_const_pointer<Tag: Provenance>(
1326 mut self,
1327 _: Pointer<Tag>,
1328 ty: Ty<'tcx>,
1329 print_ty: bool,
1330 ) -> Result<Self::Const, Self::Error> {
1331 if print_ty {
1332 self.typed_value(
1333 |mut this| {
1334 this.write_str("&_")?;
1335 Ok(this)
1336 },
1337 |this| this.print_type(ty),
1338 ": ",
1339 )
1340 } else {
1341 self.write_str("&_")?;
1342 Ok(self)
1343 }
1344 }
1345
pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error>1346 fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
1347 define_scoped_cx!(self);
1348 p!("b\"");
1349 for &c in byte_str {
1350 for e in std::ascii::escape_default(c) {
1351 self.write_char(e as char)?;
1352 }
1353 }
1354 p!("\"");
1355 Ok(self)
1356 }
1357
pretty_print_const_value( mut self, ct: ConstValue<'tcx>, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1358 fn pretty_print_const_value(
1359 mut self,
1360 ct: ConstValue<'tcx>,
1361 ty: Ty<'tcx>,
1362 print_ty: bool,
1363 ) -> Result<Self::Const, Self::Error> {
1364 define_scoped_cx!(self);
1365
1366 if self.tcx().sess.verbose() {
1367 p!(write("ConstValue({:?}: ", ct), print(ty), ")");
1368 return Ok(self);
1369 }
1370
1371 let u8_type = self.tcx().types.u8;
1372
1373 match (ct, ty.kind()) {
1374 // Byte/string slices, printed as (byte) string literals.
1375 (
1376 ConstValue::Slice { data, start, end },
1377 ty::Ref(_, ty::TyS { kind: ty::Slice(t), .. }, _),
1378 ) if *t == u8_type => {
1379 // The `inspect` here is okay since we checked the bounds, and there are
1380 // no relocations (we have an active slice reference here). We don't use
1381 // this result to affect interpreter execution.
1382 let byte_str = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1383 self.pretty_print_byte_str(byte_str)
1384 }
1385 (
1386 ConstValue::Slice { data, start, end },
1387 ty::Ref(_, ty::TyS { kind: ty::Str, .. }, _),
1388 ) => {
1389 // The `inspect` here is okay since we checked the bounds, and there are no
1390 // relocations (we have an active `str` reference here). We don't use this
1391 // result to affect interpreter execution.
1392 let slice = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1393 let s = std::str::from_utf8(slice).expect("non utf8 str from miri");
1394 p!(write("{:?}", s));
1395 Ok(self)
1396 }
1397 (ConstValue::ByRef { alloc, offset }, ty::Array(t, n)) if *t == u8_type => {
1398 let n = n.val.try_to_bits(self.tcx().data_layout.pointer_size).unwrap();
1399 // cast is ok because we already checked for pointer size (32 or 64 bit) above
1400 let range = AllocRange { start: offset, size: Size::from_bytes(n) };
1401
1402 let byte_str = alloc.get_bytes(&self.tcx(), range).unwrap();
1403 p!("*");
1404 p!(pretty_print_byte_str(byte_str));
1405 Ok(self)
1406 }
1407
1408 // Aggregates, printed as array/tuple/struct/variant construction syntax.
1409 //
1410 // NB: the `potentially_has_param_types_or_consts` check ensures that we can use
1411 // the `destructure_const` query with an empty `ty::ParamEnv` without
1412 // introducing ICEs (e.g. via `layout_of`) from missing bounds.
1413 // E.g. `transmute([0usize; 2]): (u8, *mut T)` needs to know `T: Sized`
1414 // to be able to destructure the tuple into `(0u8, *mut T)
1415 //
1416 // FIXME(eddyb) for `--emit=mir`/`-Z dump-mir`, we should provide the
1417 // correct `ty::ParamEnv` to allow printing *all* constant values.
1418 (_, ty::Array(..) | ty::Tuple(..) | ty::Adt(..))
1419 if !ty.potentially_has_param_types_or_consts() =>
1420 {
1421 let contents = self.tcx().destructure_const(
1422 ty::ParamEnv::reveal_all()
1423 .and(self.tcx().mk_const(ty::Const { val: ty::ConstKind::Value(ct), ty })),
1424 );
1425 let fields = contents.fields.iter().copied();
1426
1427 match *ty.kind() {
1428 ty::Array(..) => {
1429 p!("[", comma_sep(fields), "]");
1430 }
1431 ty::Tuple(..) => {
1432 p!("(", comma_sep(fields));
1433 if contents.fields.len() == 1 {
1434 p!(",");
1435 }
1436 p!(")");
1437 }
1438 ty::Adt(def, _) if def.variants.is_empty() => {
1439 self = self.typed_value(
1440 |mut this| {
1441 write!(this, "unreachable()")?;
1442 Ok(this)
1443 },
1444 |this| this.print_type(ty),
1445 ": ",
1446 )?;
1447 }
1448 ty::Adt(def, substs) => {
1449 let variant_idx =
1450 contents.variant.expect("destructed const of adt without variant idx");
1451 let variant_def = &def.variants[variant_idx];
1452 p!(print_value_path(variant_def.def_id, substs));
1453
1454 match variant_def.ctor_kind {
1455 CtorKind::Const => {}
1456 CtorKind::Fn => {
1457 p!("(", comma_sep(fields), ")");
1458 }
1459 CtorKind::Fictive => {
1460 p!(" {{ ");
1461 let mut first = true;
1462 for (field_def, field) in iter::zip(&variant_def.fields, fields) {
1463 if !first {
1464 p!(", ");
1465 }
1466 p!(write("{}: ", field_def.ident), print(field));
1467 first = false;
1468 }
1469 p!(" }}");
1470 }
1471 }
1472 }
1473 _ => unreachable!(),
1474 }
1475
1476 Ok(self)
1477 }
1478
1479 (ConstValue::Scalar(scalar), _) => self.pretty_print_const_scalar(scalar, ty, print_ty),
1480
1481 // FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
1482 // their fields instead of just dumping the memory.
1483 _ => {
1484 // fallback
1485 p!(write("{:?}", ct));
1486 if print_ty {
1487 p!(": ", print(ty));
1488 }
1489 Ok(self)
1490 }
1491 }
1492 }
1493 }
1494
1495 // HACK(eddyb) boxed to avoid moving around a large struct by-value.
1496 pub struct FmtPrinter<'a, 'tcx, F>(Box<FmtPrinterData<'a, 'tcx, F>>);
1497
1498 pub struct FmtPrinterData<'a, 'tcx, F> {
1499 tcx: TyCtxt<'tcx>,
1500 fmt: F,
1501
1502 empty_path: bool,
1503 in_value: bool,
1504 pub print_alloc_ids: bool,
1505
1506 used_region_names: FxHashSet<Symbol>,
1507 region_index: usize,
1508 binder_depth: usize,
1509 printed_type_count: usize,
1510
1511 pub region_highlight_mode: RegionHighlightMode,
1512
1513 pub name_resolver: Option<Box<&'a dyn Fn(ty::TyVid) -> Option<String>>>,
1514 }
1515
1516 impl<F> Deref for FmtPrinter<'a, 'tcx, F> {
1517 type Target = FmtPrinterData<'a, 'tcx, F>;
deref(&self) -> &Self::Target1518 fn deref(&self) -> &Self::Target {
1519 &self.0
1520 }
1521 }
1522
1523 impl<F> DerefMut for FmtPrinter<'_, '_, F> {
deref_mut(&mut self) -> &mut Self::Target1524 fn deref_mut(&mut self) -> &mut Self::Target {
1525 &mut self.0
1526 }
1527 }
1528
1529 impl<F> FmtPrinter<'a, 'tcx, F> {
new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self1530 pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
1531 FmtPrinter(Box::new(FmtPrinterData {
1532 tcx,
1533 fmt,
1534 empty_path: false,
1535 in_value: ns == Namespace::ValueNS,
1536 print_alloc_ids: false,
1537 used_region_names: Default::default(),
1538 region_index: 0,
1539 binder_depth: 0,
1540 printed_type_count: 0,
1541 region_highlight_mode: RegionHighlightMode::default(),
1542 name_resolver: None,
1543 }))
1544 }
1545 }
1546
1547 // HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
1548 // (but also some things just print a `DefId` generally so maybe we need this?)
guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace1549 fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
1550 match tcx.def_key(def_id).disambiguated_data.data {
1551 DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
1552 Namespace::TypeNS
1553 }
1554
1555 DefPathData::ValueNs(..)
1556 | DefPathData::AnonConst
1557 | DefPathData::ClosureExpr
1558 | DefPathData::Ctor => Namespace::ValueNS,
1559
1560 DefPathData::MacroNs(..) => Namespace::MacroNS,
1561
1562 _ => Namespace::TypeNS,
1563 }
1564 }
1565
1566 impl TyCtxt<'t> {
1567 /// Returns a string identifying this `DefId`. This string is
1568 /// suitable for user output.
def_path_str(self, def_id: DefId) -> String1569 pub fn def_path_str(self, def_id: DefId) -> String {
1570 self.def_path_str_with_substs(def_id, &[])
1571 }
1572
def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String1573 pub fn def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String {
1574 let ns = guess_def_namespace(self, def_id);
1575 debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
1576 let mut s = String::new();
1577 let _ = FmtPrinter::new(self, &mut s, ns).print_def_path(def_id, substs);
1578 s
1579 }
1580 }
1581
1582 impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
write_str(&mut self, s: &str) -> fmt::Result1583 fn write_str(&mut self, s: &str) -> fmt::Result {
1584 self.fmt.write_str(s)
1585 }
1586 }
1587
1588 impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
1589 type Error = fmt::Error;
1590
1591 type Path = Self;
1592 type Region = Self;
1593 type Type = Self;
1594 type DynExistential = Self;
1595 type Const = Self;
1596
tcx(&'a self) -> TyCtxt<'tcx>1597 fn tcx(&'a self) -> TyCtxt<'tcx> {
1598 self.tcx
1599 }
1600
print_def_path( mut self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>1601 fn print_def_path(
1602 mut self,
1603 def_id: DefId,
1604 substs: &'tcx [GenericArg<'tcx>],
1605 ) -> Result<Self::Path, Self::Error> {
1606 define_scoped_cx!(self);
1607
1608 if substs.is_empty() {
1609 match self.try_print_trimmed_def_path(def_id)? {
1610 (cx, true) => return Ok(cx),
1611 (cx, false) => self = cx,
1612 }
1613
1614 match self.try_print_visible_def_path(def_id)? {
1615 (cx, true) => return Ok(cx),
1616 (cx, false) => self = cx,
1617 }
1618 }
1619
1620 let key = self.tcx.def_key(def_id);
1621 if let DefPathData::Impl = key.disambiguated_data.data {
1622 // Always use types for non-local impls, where types are always
1623 // available, and filename/line-number is mostly uninteresting.
1624 let use_types = !def_id.is_local() || {
1625 // Otherwise, use filename/line-number if forced.
1626 let force_no_types = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
1627 !force_no_types
1628 };
1629
1630 if !use_types {
1631 // If no type info is available, fall back to
1632 // pretty printing some span information. This should
1633 // only occur very early in the compiler pipeline.
1634 let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
1635 let span = self.tcx.def_span(def_id);
1636
1637 self = self.print_def_path(parent_def_id, &[])?;
1638
1639 // HACK(eddyb) copy of `path_append` to avoid
1640 // constructing a `DisambiguatedDefPathData`.
1641 if !self.empty_path {
1642 write!(self, "::")?;
1643 }
1644 write!(
1645 self,
1646 "<impl at {}>",
1647 // This may end up in stderr diagnostics but it may also be emitted
1648 // into MIR. Hence we use the remapped path if available
1649 self.tcx.sess.source_map().span_to_embeddable_string(span)
1650 )?;
1651 self.empty_path = false;
1652
1653 return Ok(self);
1654 }
1655 }
1656
1657 self.default_print_def_path(def_id, substs)
1658 }
1659
print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error>1660 fn print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
1661 self.pretty_print_region(region)
1662 }
1663
print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error>1664 fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
1665 let type_length_limit = self.tcx.type_length_limit();
1666 if type_length_limit.value_within_limit(self.printed_type_count) {
1667 self.printed_type_count += 1;
1668 self.pretty_print_type(ty)
1669 } else {
1670 write!(self, "...")?;
1671 Ok(self)
1672 }
1673 }
1674
print_dyn_existential( self, predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>, ) -> Result<Self::DynExistential, Self::Error>1675 fn print_dyn_existential(
1676 self,
1677 predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
1678 ) -> Result<Self::DynExistential, Self::Error> {
1679 self.pretty_print_dyn_existential(predicates)
1680 }
1681
print_const(self, ct: &'tcx ty::Const<'tcx>) -> Result<Self::Const, Self::Error>1682 fn print_const(self, ct: &'tcx ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
1683 self.pretty_print_const(ct, true)
1684 }
1685
path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error>1686 fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
1687 self.empty_path = true;
1688 if cnum == LOCAL_CRATE {
1689 if self.tcx.sess.rust_2018() {
1690 // We add the `crate::` keyword on Rust 2018, only when desired.
1691 if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
1692 write!(self, "{}", kw::Crate)?;
1693 self.empty_path = false;
1694 }
1695 }
1696 } else {
1697 write!(self, "{}", self.tcx.crate_name(cnum))?;
1698 self.empty_path = false;
1699 }
1700 Ok(self)
1701 }
1702
path_qualified( mut self, self_ty: Ty<'tcx>, trait_ref: Option<ty::TraitRef<'tcx>>, ) -> Result<Self::Path, Self::Error>1703 fn path_qualified(
1704 mut self,
1705 self_ty: Ty<'tcx>,
1706 trait_ref: Option<ty::TraitRef<'tcx>>,
1707 ) -> Result<Self::Path, Self::Error> {
1708 self = self.pretty_path_qualified(self_ty, trait_ref)?;
1709 self.empty_path = false;
1710 Ok(self)
1711 }
1712
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>1713 fn path_append_impl(
1714 mut self,
1715 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1716 _disambiguated_data: &DisambiguatedDefPathData,
1717 self_ty: Ty<'tcx>,
1718 trait_ref: Option<ty::TraitRef<'tcx>>,
1719 ) -> Result<Self::Path, Self::Error> {
1720 self = self.pretty_path_append_impl(
1721 |mut cx| {
1722 cx = print_prefix(cx)?;
1723 if !cx.empty_path {
1724 write!(cx, "::")?;
1725 }
1726
1727 Ok(cx)
1728 },
1729 self_ty,
1730 trait_ref,
1731 )?;
1732 self.empty_path = false;
1733 Ok(self)
1734 }
1735
path_append( mut self, print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, disambiguated_data: &DisambiguatedDefPathData, ) -> Result<Self::Path, Self::Error>1736 fn path_append(
1737 mut self,
1738 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1739 disambiguated_data: &DisambiguatedDefPathData,
1740 ) -> Result<Self::Path, Self::Error> {
1741 self = print_prefix(self)?;
1742
1743 // Skip `::{{constructor}}` on tuple/unit structs.
1744 if let DefPathData::Ctor = disambiguated_data.data {
1745 return Ok(self);
1746 }
1747
1748 // FIXME(eddyb) `name` should never be empty, but it
1749 // currently is for `extern { ... }` "foreign modules".
1750 let name = disambiguated_data.data.name();
1751 if name != DefPathDataName::Named(kw::Empty) {
1752 if !self.empty_path {
1753 write!(self, "::")?;
1754 }
1755
1756 if let DefPathDataName::Named(name) = name {
1757 if Ident::with_dummy_span(name).is_raw_guess() {
1758 write!(self, "r#")?;
1759 }
1760 }
1761
1762 let verbose = self.tcx.sess.verbose();
1763 disambiguated_data.fmt_maybe_verbose(&mut self, verbose)?;
1764
1765 self.empty_path = false;
1766 }
1767
1768 Ok(self)
1769 }
1770
path_generic_args( mut self, print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, args: &[GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>1771 fn path_generic_args(
1772 mut self,
1773 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1774 args: &[GenericArg<'tcx>],
1775 ) -> Result<Self::Path, Self::Error> {
1776 self = print_prefix(self)?;
1777
1778 // Don't print `'_` if there's no unerased regions.
1779 let print_regions = args.iter().any(|arg| match arg.unpack() {
1780 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
1781 _ => false,
1782 });
1783 let args = args.iter().cloned().filter(|arg| match arg.unpack() {
1784 GenericArgKind::Lifetime(_) => print_regions,
1785 _ => true,
1786 });
1787
1788 if args.clone().next().is_some() {
1789 if self.in_value {
1790 write!(self, "::")?;
1791 }
1792 self.generic_delimiters(|cx| cx.comma_sep(args))
1793 } else {
1794 Ok(self)
1795 }
1796 }
1797 }
1798
1799 impl<F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
infer_ty_name(&self, id: ty::TyVid) -> Option<String>1800 fn infer_ty_name(&self, id: ty::TyVid) -> Option<String> {
1801 self.0.name_resolver.as_ref().and_then(|func| func(id))
1802 }
1803
print_value_path( mut self, def_id: DefId, substs: &'tcx [GenericArg<'tcx>], ) -> Result<Self::Path, Self::Error>1804 fn print_value_path(
1805 mut self,
1806 def_id: DefId,
1807 substs: &'tcx [GenericArg<'tcx>],
1808 ) -> Result<Self::Path, Self::Error> {
1809 let was_in_value = std::mem::replace(&mut self.in_value, true);
1810 self = self.print_def_path(def_id, substs)?;
1811 self.in_value = was_in_value;
1812
1813 Ok(self)
1814 }
1815
in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,1816 fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
1817 where
1818 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
1819 {
1820 self.pretty_in_binder(value)
1821 }
1822
wrap_binder<T, C: Fn(&T, Self) -> Result<Self, Self::Error>>( self, value: &ty::Binder<'tcx, T>, f: C, ) -> Result<Self, Self::Error> where T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,1823 fn wrap_binder<T, C: Fn(&T, Self) -> Result<Self, Self::Error>>(
1824 self,
1825 value: &ty::Binder<'tcx, T>,
1826 f: C,
1827 ) -> Result<Self, Self::Error>
1828 where
1829 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
1830 {
1831 self.pretty_wrap_binder(value, f)
1832 }
1833
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>1834 fn typed_value(
1835 mut self,
1836 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1837 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
1838 conversion: &str,
1839 ) -> Result<Self::Const, Self::Error> {
1840 self.write_str("{")?;
1841 self = f(self)?;
1842 self.write_str(conversion)?;
1843 let was_in_value = std::mem::replace(&mut self.in_value, false);
1844 self = t(self)?;
1845 self.in_value = was_in_value;
1846 self.write_str("}")?;
1847 Ok(self)
1848 }
1849
generic_delimiters( mut self, f: impl FnOnce(Self) -> Result<Self, Self::Error>, ) -> Result<Self, Self::Error>1850 fn generic_delimiters(
1851 mut self,
1852 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1853 ) -> Result<Self, Self::Error> {
1854 write!(self, "<")?;
1855
1856 let was_in_value = std::mem::replace(&mut self.in_value, false);
1857 let mut inner = f(self)?;
1858 inner.in_value = was_in_value;
1859
1860 write!(inner, ">")?;
1861 Ok(inner)
1862 }
1863
region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool1864 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool {
1865 let highlight = self.region_highlight_mode;
1866 if highlight.region_highlighted(region).is_some() {
1867 return true;
1868 }
1869
1870 if self.tcx.sess.verbose() {
1871 return true;
1872 }
1873
1874 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1875
1876 match *region {
1877 ty::ReEarlyBound(ref data) => {
1878 data.name != kw::Empty && data.name != kw::UnderscoreLifetime
1879 }
1880
1881 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
1882 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1883 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1884 if let ty::BrNamed(_, name) = br {
1885 if name != kw::Empty && name != kw::UnderscoreLifetime {
1886 return true;
1887 }
1888 }
1889
1890 if let Some((region, _)) = highlight.highlight_bound_region {
1891 if br == region {
1892 return true;
1893 }
1894 }
1895
1896 false
1897 }
1898
1899 ty::ReVar(_) if identify_regions => true,
1900
1901 ty::ReVar(_) | ty::ReErased => false,
1902
1903 ty::ReStatic | ty::ReEmpty(_) => true,
1904 }
1905 }
1906
pretty_print_const_pointer<Tag: Provenance>( self, p: Pointer<Tag>, ty: Ty<'tcx>, print_ty: bool, ) -> Result<Self::Const, Self::Error>1907 fn pretty_print_const_pointer<Tag: Provenance>(
1908 self,
1909 p: Pointer<Tag>,
1910 ty: Ty<'tcx>,
1911 print_ty: bool,
1912 ) -> Result<Self::Const, Self::Error> {
1913 let print = |mut this: Self| {
1914 define_scoped_cx!(this);
1915 if this.print_alloc_ids {
1916 p!(write("{:?}", p));
1917 } else {
1918 p!("&_");
1919 }
1920 Ok(this)
1921 };
1922 if print_ty {
1923 self.typed_value(print, |this| this.print_type(ty), ": ")
1924 } else {
1925 print(self)
1926 }
1927 }
1928 }
1929
1930 // HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
1931 impl<F: fmt::Write> FmtPrinter<'_, '_, F> {
pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error>1932 pub fn pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error> {
1933 define_scoped_cx!(self);
1934
1935 // Watch out for region highlights.
1936 let highlight = self.region_highlight_mode;
1937 if let Some(n) = highlight.region_highlighted(region) {
1938 p!(write("'{}", n));
1939 return Ok(self);
1940 }
1941
1942 if self.tcx.sess.verbose() {
1943 p!(write("{:?}", region));
1944 return Ok(self);
1945 }
1946
1947 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1948
1949 // These printouts are concise. They do not contain all the information
1950 // the user might want to diagnose an error, but there is basically no way
1951 // to fit that into a short string. Hence the recommendation to use
1952 // `explain_region()` or `note_and_explain_region()`.
1953 match *region {
1954 ty::ReEarlyBound(ref data) => {
1955 if data.name != kw::Empty {
1956 p!(write("{}", data.name));
1957 return Ok(self);
1958 }
1959 }
1960 ty::ReLateBound(_, ty::BoundRegion { kind: br, .. })
1961 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1962 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1963 if let ty::BrNamed(_, name) = br {
1964 if name != kw::Empty && name != kw::UnderscoreLifetime {
1965 p!(write("{}", name));
1966 return Ok(self);
1967 }
1968 }
1969
1970 if let Some((region, counter)) = highlight.highlight_bound_region {
1971 if br == region {
1972 p!(write("'{}", counter));
1973 return Ok(self);
1974 }
1975 }
1976 }
1977 ty::ReVar(region_vid) if identify_regions => {
1978 p!(write("{:?}", region_vid));
1979 return Ok(self);
1980 }
1981 ty::ReVar(_) => {}
1982 ty::ReErased => {}
1983 ty::ReStatic => {
1984 p!("'static");
1985 return Ok(self);
1986 }
1987 ty::ReEmpty(ty::UniverseIndex::ROOT) => {
1988 p!("'<empty>");
1989 return Ok(self);
1990 }
1991 ty::ReEmpty(ui) => {
1992 p!(write("'<empty:{:?}>", ui));
1993 return Ok(self);
1994 }
1995 }
1996
1997 p!("'_");
1998
1999 Ok(self)
2000 }
2001 }
2002
2003 /// Folds through bound vars and placeholders, naming them
2004 struct RegionFolder<'a, 'tcx> {
2005 tcx: TyCtxt<'tcx>,
2006 current_index: ty::DebruijnIndex,
2007 region_map: BTreeMap<ty::BoundRegion, ty::Region<'tcx>>,
2008 name: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a),
2009 }
2010
2011 impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> {
tcx<'b>(&'b self) -> TyCtxt<'tcx>2012 fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
2013 self.tcx
2014 }
2015
fold_binder<T: TypeFoldable<'tcx>>( &mut self, t: ty::Binder<'tcx, T>, ) -> ty::Binder<'tcx, T>2016 fn fold_binder<T: TypeFoldable<'tcx>>(
2017 &mut self,
2018 t: ty::Binder<'tcx, T>,
2019 ) -> ty::Binder<'tcx, T> {
2020 self.current_index.shift_in(1);
2021 let t = t.super_fold_with(self);
2022 self.current_index.shift_out(1);
2023 t
2024 }
2025
fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx>2026 fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
2027 match *t.kind() {
2028 _ if t.has_vars_bound_at_or_above(self.current_index) || t.has_placeholders() => {
2029 return t.super_fold_with(self);
2030 }
2031 _ => {}
2032 }
2033 t
2034 }
2035
fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx>2036 fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
2037 let name = &mut self.name;
2038 let region = match *r {
2039 ty::ReLateBound(_, br) => self.region_map.entry(br).or_insert_with(|| name(br)),
2040 ty::RePlaceholder(ty::PlaceholderRegion { name: kind, .. }) => {
2041 // If this is an anonymous placeholder, don't rename. Otherwise, in some
2042 // async fns, we get a `for<'r> Send` bound
2043 match kind {
2044 ty::BrAnon(_) | ty::BrEnv => r,
2045 _ => {
2046 // Index doesn't matter, since this is just for naming and these never get bound
2047 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind };
2048 self.region_map.entry(br).or_insert_with(|| name(br))
2049 }
2050 }
2051 }
2052 _ => return r,
2053 };
2054 if let ty::ReLateBound(debruijn1, br) = *region {
2055 assert_eq!(debruijn1, ty::INNERMOST);
2056 self.tcx.mk_region(ty::ReLateBound(self.current_index, br))
2057 } else {
2058 region
2059 }
2060 }
2061 }
2062
2063 // HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
2064 // `region_index` and `used_region_names`.
2065 impl<F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
name_all_regions<T>( mut self, value: &ty::Binder<'tcx, T>, ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error> where T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,2066 pub fn name_all_regions<T>(
2067 mut self,
2068 value: &ty::Binder<'tcx, T>,
2069 ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
2070 where
2071 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2072 {
2073 fn name_by_region_index(index: usize) -> Symbol {
2074 match index {
2075 0 => Symbol::intern("'r"),
2076 1 => Symbol::intern("'s"),
2077 i => Symbol::intern(&format!("'t{}", i - 2)),
2078 }
2079 }
2080
2081 // Replace any anonymous late-bound regions with named
2082 // variants, using new unique identifiers, so that we can
2083 // clearly differentiate between named and unnamed regions in
2084 // the output. We'll probably want to tweak this over time to
2085 // decide just how much information to give.
2086 if self.binder_depth == 0 {
2087 self.prepare_late_bound_region_info(value);
2088 }
2089
2090 let mut empty = true;
2091 let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
2092 let w = if empty {
2093 empty = false;
2094 start
2095 } else {
2096 cont
2097 };
2098 let _ = write!(cx, "{}", w);
2099 };
2100 let do_continue = |cx: &mut Self, cont: Symbol| {
2101 let _ = write!(cx, "{}", cont);
2102 };
2103
2104 define_scoped_cx!(self);
2105
2106 let mut region_index = self.region_index;
2107 // If we want to print verbosly, then print *all* binders, even if they
2108 // aren't named. Eventually, we might just want this as the default, but
2109 // this is not *quite* right and changes the ordering of some output
2110 // anyways.
2111 let (new_value, map) = if self.tcx().sess.verbose() {
2112 // anon index + 1 (BrEnv takes 0) -> name
2113 let mut region_map: BTreeMap<u32, Symbol> = BTreeMap::default();
2114 let bound_vars = value.bound_vars();
2115 for var in bound_vars {
2116 match var {
2117 ty::BoundVariableKind::Region(ty::BrNamed(_, name)) => {
2118 start_or_continue(&mut self, "for<", ", ");
2119 do_continue(&mut self, name);
2120 }
2121 ty::BoundVariableKind::Region(ty::BrAnon(i)) => {
2122 start_or_continue(&mut self, "for<", ", ");
2123 let name = loop {
2124 let name = name_by_region_index(region_index);
2125 region_index += 1;
2126 if !self.used_region_names.contains(&name) {
2127 break name;
2128 }
2129 };
2130 do_continue(&mut self, name);
2131 region_map.insert(i + 1, name);
2132 }
2133 ty::BoundVariableKind::Region(ty::BrEnv) => {
2134 start_or_continue(&mut self, "for<", ", ");
2135 let name = loop {
2136 let name = name_by_region_index(region_index);
2137 region_index += 1;
2138 if !self.used_region_names.contains(&name) {
2139 break name;
2140 }
2141 };
2142 do_continue(&mut self, name);
2143 region_map.insert(0, name);
2144 }
2145 _ => continue,
2146 }
2147 }
2148 start_or_continue(&mut self, "", "> ");
2149
2150 self.tcx.replace_late_bound_regions(value.clone(), |br| {
2151 let kind = match br.kind {
2152 ty::BrNamed(_, _) => br.kind,
2153 ty::BrAnon(i) => {
2154 let name = region_map[&(i + 1)];
2155 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2156 }
2157 ty::BrEnv => {
2158 let name = region_map[&0];
2159 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2160 }
2161 };
2162 self.tcx.mk_region(ty::ReLateBound(
2163 ty::INNERMOST,
2164 ty::BoundRegion { var: br.var, kind },
2165 ))
2166 })
2167 } else {
2168 let tcx = self.tcx;
2169 let mut name = |br: ty::BoundRegion| {
2170 start_or_continue(&mut self, "for<", ", ");
2171 let kind = match br.kind {
2172 ty::BrNamed(_, name) => {
2173 do_continue(&mut self, name);
2174 br.kind
2175 }
2176 ty::BrAnon(_) | ty::BrEnv => {
2177 let name = loop {
2178 let name = name_by_region_index(region_index);
2179 region_index += 1;
2180 if !self.used_region_names.contains(&name) {
2181 break name;
2182 }
2183 };
2184 do_continue(&mut self, name);
2185 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
2186 }
2187 };
2188 tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { var: br.var, kind }))
2189 };
2190 let mut folder = RegionFolder {
2191 tcx,
2192 current_index: ty::INNERMOST,
2193 name: &mut name,
2194 region_map: BTreeMap::new(),
2195 };
2196 let new_value = value.clone().skip_binder().fold_with(&mut folder);
2197 let region_map = folder.region_map;
2198 start_or_continue(&mut self, "", "> ");
2199 (new_value, region_map)
2200 };
2201
2202 self.binder_depth += 1;
2203 self.region_index = region_index;
2204 Ok((self, new_value, map))
2205 }
2206
pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error> where T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,2207 pub fn pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error>
2208 where
2209 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2210 {
2211 let old_region_index = self.region_index;
2212 let (new, new_value, _) = self.name_all_regions(value)?;
2213 let mut inner = new_value.print(new)?;
2214 inner.region_index = old_region_index;
2215 inner.binder_depth -= 1;
2216 Ok(inner)
2217 }
2218
pretty_wrap_binder<T, C: Fn(&T, Self) -> Result<Self, fmt::Error>>( self, value: &ty::Binder<'tcx, T>, f: C, ) -> Result<Self, fmt::Error> where T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,2219 pub fn pretty_wrap_binder<T, C: Fn(&T, Self) -> Result<Self, fmt::Error>>(
2220 self,
2221 value: &ty::Binder<'tcx, T>,
2222 f: C,
2223 ) -> Result<Self, fmt::Error>
2224 where
2225 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
2226 {
2227 let old_region_index = self.region_index;
2228 let (new, new_value, _) = self.name_all_regions(value)?;
2229 let mut inner = f(&new_value, new)?;
2230 inner.region_index = old_region_index;
2231 inner.binder_depth -= 1;
2232 Ok(inner)
2233 }
2234
2235 #[instrument(skip(self), level = "debug")]
prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>) where T: TypeFoldable<'tcx>,2236 fn prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
2237 where
2238 T: TypeFoldable<'tcx>,
2239 {
2240 struct LateBoundRegionNameCollector<'a, 'tcx> {
2241 tcx: TyCtxt<'tcx>,
2242 used_region_names: &'a mut FxHashSet<Symbol>,
2243 type_collector: SsoHashSet<Ty<'tcx>>,
2244 }
2245
2246 impl<'tcx> ty::fold::TypeVisitor<'tcx> for LateBoundRegionNameCollector<'_, 'tcx> {
2247 type BreakTy = ();
2248
2249 fn tcx_for_anon_const_substs(&self) -> Option<TyCtxt<'tcx>> {
2250 Some(self.tcx)
2251 }
2252
2253 #[instrument(skip(self), level = "trace")]
2254 fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
2255 trace!("address: {:p}", r);
2256 if let ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrNamed(_, name), .. }) = *r {
2257 self.used_region_names.insert(name);
2258 } else if let ty::RePlaceholder(ty::PlaceholderRegion {
2259 name: ty::BrNamed(_, name),
2260 ..
2261 }) = *r
2262 {
2263 self.used_region_names.insert(name);
2264 }
2265 r.super_visit_with(self)
2266 }
2267
2268 // We collect types in order to prevent really large types from compiling for
2269 // a really long time. See issue #83150 for why this is necessary.
2270 #[instrument(skip(self), level = "trace")]
2271 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
2272 let not_previously_inserted = self.type_collector.insert(ty);
2273 if not_previously_inserted {
2274 ty.super_visit_with(self)
2275 } else {
2276 ControlFlow::CONTINUE
2277 }
2278 }
2279 }
2280
2281 self.used_region_names.clear();
2282 let mut collector = LateBoundRegionNameCollector {
2283 tcx: self.tcx,
2284 used_region_names: &mut self.used_region_names,
2285 type_collector: SsoHashSet::new(),
2286 };
2287 value.visit_with(&mut collector);
2288 self.region_index = 0;
2289 }
2290 }
2291
2292 impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
2293 where
2294 T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
2295 {
2296 type Output = P;
2297 type Error = P::Error;
print(&self, cx: P) -> Result<Self::Output, Self::Error>2298 fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
2299 cx.in_binder(self)
2300 }
2301 }
2302
2303 impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
2304 where
2305 T: Print<'tcx, P, Output = P, Error = P::Error>,
2306 U: Print<'tcx, P, Output = P, Error = P::Error>,
2307 {
2308 type Output = P;
2309 type Error = P::Error;
print(&self, mut cx: P) -> Result<Self::Output, Self::Error>2310 fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
2311 define_scoped_cx!(cx);
2312 p!(print(self.0), ": ", print(self.1));
2313 Ok(cx)
2314 }
2315 }
2316
2317 macro_rules! forward_display_to_print {
2318 ($($ty:ty),+) => {
2319 $(impl fmt::Display for $ty {
2320 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2321 ty::tls::with(|tcx| {
2322 tcx.lift(*self)
2323 .expect("could not lift for printing")
2324 .print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
2325 Ok(())
2326 })
2327 }
2328 })+
2329 };
2330 }
2331
2332 macro_rules! define_print_and_forward_display {
2333 (($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
2334 $(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
2335 type Output = P;
2336 type Error = fmt::Error;
2337 fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
2338 #[allow(unused_mut)]
2339 let mut $cx = $cx;
2340 define_scoped_cx!($cx);
2341 let _: () = $print;
2342 #[allow(unreachable_code)]
2343 Ok($cx)
2344 }
2345 })+
2346
2347 forward_display_to_print!($($ty),+);
2348 };
2349 }
2350
2351 // HACK(eddyb) this is separate because `ty::RegionKind` doesn't need lifting.
2352 impl fmt::Display for ty::RegionKind {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2353 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2354 ty::tls::with(|tcx| {
2355 self.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
2356 Ok(())
2357 })
2358 }
2359 }
2360
2361 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2362 /// the trait path. That is, it will print `Trait<U>` instead of
2363 /// `<T as Trait<U>>`.
2364 #[derive(Copy, Clone, TypeFoldable, Lift)]
2365 pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
2366
2367 impl fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2368 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2369 fmt::Display::fmt(self, f)
2370 }
2371 }
2372
2373 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
2374 /// the trait name. That is, it will print `Trait` instead of
2375 /// `<T as Trait<U>>`.
2376 #[derive(Copy, Clone, TypeFoldable, Lift)]
2377 pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
2378
2379 impl fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result2380 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2381 fmt::Display::fmt(self, f)
2382 }
2383 }
2384
2385 impl ty::TraitRef<'tcx> {
print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx>2386 pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
2387 TraitRefPrintOnlyTraitPath(self)
2388 }
2389
print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx>2390 pub fn print_only_trait_name(self) -> TraitRefPrintOnlyTraitName<'tcx> {
2391 TraitRefPrintOnlyTraitName(self)
2392 }
2393 }
2394
2395 impl ty::Binder<'tcx, ty::TraitRef<'tcx>> {
print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>2396 pub fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
2397 self.map_bound(|tr| tr.print_only_trait_path())
2398 }
2399 }
2400
2401 forward_display_to_print! {
2402 Ty<'tcx>,
2403 &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
2404 &'tcx ty::Const<'tcx>,
2405
2406 // HACK(eddyb) these are exhaustive instead of generic,
2407 // because `for<'tcx>` isn't possible yet.
2408 ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>,
2409 ty::Binder<'tcx, ty::TraitRef<'tcx>>,
2410 ty::Binder<'tcx, ty::ExistentialTraitRef<'tcx>>,
2411 ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>>,
2412 ty::Binder<'tcx, TraitRefPrintOnlyTraitName<'tcx>>,
2413 ty::Binder<'tcx, ty::FnSig<'tcx>>,
2414 ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,
2415 ty::Binder<'tcx, ty::SubtypePredicate<'tcx>>,
2416 ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
2417 ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
2418 ty::Binder<'tcx, ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
2419
2420 ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
2421 ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
2422 }
2423
2424 define_print_and_forward_display! {
2425 (self, cx):
2426
2427 &'tcx ty::List<Ty<'tcx>> {
2428 p!("{{", comma_sep(self.iter()), "}}")
2429 }
2430
2431 ty::TypeAndMut<'tcx> {
2432 p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
2433 }
2434
2435 ty::ExistentialTraitRef<'tcx> {
2436 // Use a type that can't appear in defaults of type parameters.
2437 let dummy_self = cx.tcx().mk_ty_infer(ty::FreshTy(0));
2438 let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
2439 p!(print(trait_ref.print_only_trait_path()))
2440 }
2441
2442 ty::ExistentialProjection<'tcx> {
2443 let name = cx.tcx().associated_item(self.item_def_id).ident;
2444 p!(write("{} = ", name), print(self.ty))
2445 }
2446
2447 ty::ExistentialPredicate<'tcx> {
2448 match *self {
2449 ty::ExistentialPredicate::Trait(x) => p!(print(x)),
2450 ty::ExistentialPredicate::Projection(x) => p!(print(x)),
2451 ty::ExistentialPredicate::AutoTrait(def_id) => {
2452 p!(print_def_path(def_id, &[]));
2453 }
2454 }
2455 }
2456
2457 ty::FnSig<'tcx> {
2458 p!(write("{}", self.unsafety.prefix_str()));
2459
2460 if self.abi != Abi::Rust {
2461 p!(write("extern {} ", self.abi));
2462 }
2463
2464 p!("fn", pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
2465 }
2466
2467 ty::TraitRef<'tcx> {
2468 p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
2469 }
2470
2471 TraitRefPrintOnlyTraitPath<'tcx> {
2472 p!(print_def_path(self.0.def_id, self.0.substs));
2473 }
2474
2475 TraitRefPrintOnlyTraitName<'tcx> {
2476 p!(print_def_path(self.0.def_id, &[]));
2477 }
2478
2479 ty::ParamTy {
2480 p!(write("{}", self.name))
2481 }
2482
2483 ty::ParamConst {
2484 p!(write("{}", self.name))
2485 }
2486
2487 ty::SubtypePredicate<'tcx> {
2488 p!(print(self.a), " <: ", print(self.b))
2489 }
2490
2491 ty::CoercePredicate<'tcx> {
2492 p!(print(self.a), " -> ", print(self.b))
2493 }
2494
2495 ty::TraitPredicate<'tcx> {
2496 p!(print(self.trait_ref.self_ty()), ": ",
2497 print(self.trait_ref.print_only_trait_path()))
2498 }
2499
2500 ty::ProjectionPredicate<'tcx> {
2501 p!(print(self.projection_ty), " == ", print(self.ty))
2502 }
2503
2504 ty::ProjectionTy<'tcx> {
2505 p!(print_def_path(self.item_def_id, self.substs));
2506 }
2507
2508 ty::ClosureKind {
2509 match *self {
2510 ty::ClosureKind::Fn => p!("Fn"),
2511 ty::ClosureKind::FnMut => p!("FnMut"),
2512 ty::ClosureKind::FnOnce => p!("FnOnce"),
2513 }
2514 }
2515
2516 ty::Predicate<'tcx> {
2517 let binder = self.kind();
2518 p!(print(binder))
2519 }
2520
2521 ty::PredicateKind<'tcx> {
2522 match *self {
2523 ty::PredicateKind::Trait(ref data) => {
2524 p!(print(data))
2525 }
2526 ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
2527 ty::PredicateKind::Coerce(predicate) => p!(print(predicate)),
2528 ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)),
2529 ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)),
2530 ty::PredicateKind::Projection(predicate) => p!(print(predicate)),
2531 ty::PredicateKind::WellFormed(arg) => p!(print(arg), " well-formed"),
2532 ty::PredicateKind::ObjectSafe(trait_def_id) => {
2533 p!("the trait `", print_def_path(trait_def_id, &[]), "` is object-safe")
2534 }
2535 ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => {
2536 p!("the closure `",
2537 print_value_path(closure_def_id, &[]),
2538 write("` implements the trait `{}`", kind))
2539 }
2540 ty::PredicateKind::ConstEvaluatable(uv) => {
2541 p!("the constant `", print_value_path(uv.def.did, uv.substs_.map_or(&[], |x| x)), "` can be evaluated")
2542 }
2543 ty::PredicateKind::ConstEquate(c1, c2) => {
2544 p!("the constant `", print(c1), "` equals `", print(c2), "`")
2545 }
2546 ty::PredicateKind::TypeWellFormedFromEnv(ty) => {
2547 p!("the type `", print(ty), "` is found in the environment")
2548 }
2549 }
2550 }
2551
2552 GenericArg<'tcx> {
2553 match self.unpack() {
2554 GenericArgKind::Lifetime(lt) => p!(print(lt)),
2555 GenericArgKind::Type(ty) => p!(print(ty)),
2556 GenericArgKind::Const(ct) => p!(print(ct)),
2557 }
2558 }
2559 }
2560
for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId))2561 fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, Namespace, DefId)) {
2562 // Iterate all local crate items no matter where they are defined.
2563 let hir = tcx.hir();
2564 for item in hir.items() {
2565 if item.ident.name.as_str().is_empty() || matches!(item.kind, ItemKind::Use(_, _)) {
2566 continue;
2567 }
2568
2569 let def_id = item.def_id.to_def_id();
2570 let ns = tcx.def_kind(def_id).ns().unwrap_or(Namespace::TypeNS);
2571 collect_fn(&item.ident, ns, def_id);
2572 }
2573
2574 // Now take care of extern crate items.
2575 let queue = &mut Vec::new();
2576 let mut seen_defs: DefIdSet = Default::default();
2577
2578 for &cnum in tcx.crates(()).iter() {
2579 let def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX };
2580
2581 // Ignore crates that are not direct dependencies.
2582 match tcx.extern_crate(def_id) {
2583 None => continue,
2584 Some(extern_crate) => {
2585 if !extern_crate.is_direct() {
2586 continue;
2587 }
2588 }
2589 }
2590
2591 queue.push(def_id);
2592 }
2593
2594 // Iterate external crate defs but be mindful about visibility
2595 while let Some(def) = queue.pop() {
2596 for child in tcx.item_children(def).iter() {
2597 if !child.vis.is_public() {
2598 continue;
2599 }
2600
2601 match child.res {
2602 def::Res::Def(DefKind::AssocTy, _) => {}
2603 def::Res::Def(DefKind::TyAlias, _) => {}
2604 def::Res::Def(defkind, def_id) => {
2605 if let Some(ns) = defkind.ns() {
2606 collect_fn(&child.ident, ns, def_id);
2607 }
2608
2609 if seen_defs.insert(def_id) {
2610 queue.push(def_id);
2611 }
2612 }
2613 _ => {}
2614 }
2615 }
2616 }
2617 }
2618
2619 /// The purpose of this function is to collect public symbols names that are unique across all
2620 /// crates in the build. Later, when printing about types we can use those names instead of the
2621 /// full exported path to them.
2622 ///
2623 /// So essentially, if a symbol name can only be imported from one place for a type, and as
2624 /// long as it was not glob-imported anywhere in the current crate, we can trim its printed
2625 /// path and print only the name.
2626 ///
2627 /// This has wide implications on error messages with types, for example, shortening
2628 /// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere.
2629 ///
2630 /// The implementation uses similar import discovery logic to that of 'use' suggestions.
trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol>2631 fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> {
2632 let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default();
2633
2634 if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
2635 // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
2636 // wrapper can be used to suppress this query, in exchange for full paths being formatted.
2637 tcx.sess.delay_good_path_bug("trimmed_def_paths constructed");
2638 }
2639
2640 let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
2641 &mut FxHashMap::default();
2642
2643 for symbol_set in tcx.resolutions(()).glob_map.values() {
2644 for symbol in symbol_set {
2645 unique_symbols_rev.insert((Namespace::TypeNS, *symbol), None);
2646 unique_symbols_rev.insert((Namespace::ValueNS, *symbol), None);
2647 unique_symbols_rev.insert((Namespace::MacroNS, *symbol), None);
2648 }
2649 }
2650
2651 for_each_def(tcx, |ident, ns, def_id| {
2652 use std::collections::hash_map::Entry::{Occupied, Vacant};
2653
2654 match unique_symbols_rev.entry((ns, ident.name)) {
2655 Occupied(mut v) => match v.get() {
2656 None => {}
2657 Some(existing) => {
2658 if *existing != def_id {
2659 v.insert(None);
2660 }
2661 }
2662 },
2663 Vacant(v) => {
2664 v.insert(Some(def_id));
2665 }
2666 }
2667 });
2668
2669 for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
2670 use std::collections::hash_map::Entry::{Occupied, Vacant};
2671
2672 if let Some(def_id) = opt_def_id {
2673 match map.entry(def_id) {
2674 Occupied(mut v) => {
2675 // A single DefId can be known under multiple names (e.g.,
2676 // with a `pub use ... as ...;`). We need to ensure that the
2677 // name placed in this map is chosen deterministically, so
2678 // if we find multiple names (`symbol`) resolving to the
2679 // same `def_id`, we prefer the lexicographically smallest
2680 // name.
2681 //
2682 // Any stable ordering would be fine here though.
2683 if *v.get() != symbol {
2684 if v.get().as_str() > symbol.as_str() {
2685 v.insert(symbol);
2686 }
2687 }
2688 }
2689 Vacant(v) => {
2690 v.insert(symbol);
2691 }
2692 }
2693 }
2694 }
2695
2696 map
2697 }
2698
provide(providers: &mut ty::query::Providers)2699 pub fn provide(providers: &mut ty::query::Providers) {
2700 *providers = ty::query::Providers { trimmed_def_paths, ..*providers };
2701 }
2702
2703 #[derive(Default)]
2704 pub struct OpaqueFnEntry<'tcx> {
2705 // The trait ref is already stored as a key, so just track if we have it as a real predicate
2706 has_fn_once: bool,
2707 fn_mut_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
2708 fn_trait_ref: Option<ty::PolyTraitRef<'tcx>>,
2709 return_ty: Option<ty::Binder<'tcx, Ty<'tcx>>>,
2710 }
2711