1 use crate::middle::cstore::{ExternCrate, ExternCrateSource};
2 use crate::mir::interpret::{AllocId, ConstValue, GlobalAlloc, Pointer, Scalar};
3 use crate::ty::layout::IntegerExt;
4 use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
5 use crate::ty::{self, ConstInt, DefIdTree, ParamConst, Ty, TyCtxt, TypeFoldable};
6 use rustc_apfloat::ieee::{Double, Single};
7 use rustc_apfloat::Float;
9 use rustc_attr::{SignedInt, UnsignedInt};
11 use rustc_hir::def::{CtorKind, DefKind, Namespace};
12 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
13 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
14 use rustc_span::symbol::{kw, Ident, Symbol};
15 use rustc_target::abi::{Integer, Size};
16 use rustc_target::spec::abi::Abi;
20 use std::collections::BTreeMap;
21 use std::fmt::{self, Write as _};
22 use std::ops::{Deref, DerefMut};
24 // `pretty` is a separate module only for organization.
28 (@write($($data:expr),+)) => {
29 write!(scoped_cx!(), $($data),+)?
31 (@print($x:expr)) => {
32 scoped_cx!() = $x.print(scoped_cx!())?
34 (@$method:ident($($arg:expr),*)) => {
35 scoped_cx!() = scoped_cx!().$method($($arg),*)?
37 ($($kind:ident $data:tt),+) => {{
41 macro_rules! define_scoped_cx {
43 #[allow(unused_macros)]
44 macro_rules! scoped_cx {
53 static FORCE_IMPL_FILENAME_LINE: Cell<bool> = Cell::new(false);
54 static SHOULD_PREFIX_WITH_CRATE: Cell<bool> = Cell::new(false);
55 static NO_QUERIES: Cell<bool> = Cell::new(false);
58 /// Avoids running any queries during any prints that occur
59 /// during the closure. This may alter the appearance of some
60 /// types (e.g. forcing verbose printing for opaque types).
61 /// This method is used during some queries (e.g. `predicates_of`
62 /// for opaque types), to ensure that any debug printing that
63 /// occurs during the query computation does not end up recursively
64 /// calling the same query.
65 pub fn with_no_queries<F: FnOnce() -> R, R>(f: F) -> R {
66 NO_QUERIES.with(|no_queries| {
67 let old = no_queries.replace(true);
74 /// Force us to name impls with just the filename/line number. We
75 /// normally try to use types. But at some points, notably while printing
76 /// cycle errors, this can result in extra or suboptimal error output,
77 /// so this variable disables that check.
78 pub fn with_forced_impl_filename_line<F: FnOnce() -> R, R>(f: F) -> R {
79 FORCE_IMPL_FILENAME_LINE.with(|force| {
80 let old = force.replace(true);
87 /// Adds the `crate::` prefix to paths where appropriate.
88 pub fn with_crate_prefix<F: FnOnce() -> R, R>(f: F) -> R {
89 SHOULD_PREFIX_WITH_CRATE.with(|flag| {
90 let old = flag.replace(true);
97 /// The "region highlights" are used to control region printing during
98 /// specific error messages. When a "region highlight" is enabled, it
99 /// gives an alternate way to print specific regions. For now, we
100 /// always print those regions using a number, so something like "`'0`".
102 /// Regions not selected by the region highlight mode are presently
104 #[derive(Copy, Clone, Default)]
105 pub struct RegionHighlightMode {
106 /// If enabled, when we see the selected region, use "`'N`"
107 /// instead of the ordinary behavior.
108 highlight_regions: [Option<(ty::RegionKind, usize)>; 3],
110 /// If enabled, when printing a "free region" that originated from
111 /// the given `ty::BoundRegion`, print it as "`'1`". Free regions that would ordinarily
112 /// have names print as normal.
114 /// This is used when you have a signature like `fn foo(x: &u32,
115 /// y: &'a u32)` and we want to give a name to the region of the
117 highlight_bound_region: Option<(ty::BoundRegion, usize)>,
120 impl RegionHighlightMode {
121 /// If `region` and `number` are both `Some`, invokes
122 /// `highlighting_region`.
123 pub fn maybe_highlighting_region(
125 region: Option<ty::Region<'_>>,
126 number: Option<usize>,
128 if let Some(k) = region {
129 if let Some(n) = number {
130 self.highlighting_region(k, n);
135 /// Highlights the region inference variable `vid` as `'N`.
136 pub fn highlighting_region(&mut self, region: ty::Region<'_>, number: usize) {
137 let num_slots = self.highlight_regions.len();
138 let first_avail_slot =
139 self.highlight_regions.iter_mut().find(|s| s.is_none()).unwrap_or_else(|| {
140 bug!("can only highlight {} placeholders at a time", num_slots,)
142 *first_avail_slot = Some((*region, number));
145 /// Convenience wrapper for `highlighting_region`.
146 pub fn highlighting_region_vid(&mut self, vid: ty::RegionVid, number: usize) {
147 self.highlighting_region(&ty::ReVar(vid), number)
150 /// Returns `Some(n)` with the number to use for the given region, if any.
151 fn region_highlighted(&self, region: ty::Region<'_>) -> Option<usize> {
152 self.highlight_regions.iter().find_map(|h| match h {
153 Some((r, n)) if r == region => Some(*n),
158 /// Highlight the given bound region.
159 /// We can only highlight one bound region at a time. See
160 /// the field `highlight_bound_region` for more detailed notes.
161 pub fn highlighting_bound_region(&mut self, br: ty::BoundRegion, number: usize) {
162 assert!(self.highlight_bound_region.is_none());
163 self.highlight_bound_region = Some((br, number));
167 /// Trait for printers that pretty-print using `fmt::Write` to the printer.
168 pub trait PrettyPrinter<'tcx>:
175 DynExistential = Self,
179 /// Like `print_def_path` but for value paths.
183 substs: &'tcx [GenericArg<'tcx>],
184 ) -> Result<Self::Path, Self::Error> {
185 self.print_def_path(def_id, substs)
188 fn in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, Self::Error>
190 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
192 value.as_ref().skip_binder().print(self)
195 /// Prints comma-separated elements.
196 fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error>
198 T: Print<'tcx, Self, Output = Self, Error = Self::Error>,
200 if let Some(first) = elems.next() {
201 self = first.print(self)?;
203 self.write_str(", ")?;
204 self = elem.print(self)?;
210 /// Prints `{f: t}` or `{f as t}` depending on the `cast` argument
213 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
214 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
216 ) -> Result<Self::Const, Self::Error> {
217 self.write_str("{")?;
219 self.write_str(conversion)?;
221 self.write_str("}")?;
225 /// Prints `<...>` around what `f` prints.
226 fn generic_delimiters(
228 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
229 ) -> Result<Self, Self::Error>;
231 /// Returns `true` if the region should be printed in
232 /// optional positions, e.g., `&'a T` or `dyn Tr + 'b`.
233 /// This is typically the case for all non-`'_` regions.
234 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool;
236 // Defaults (should not be overridden):
238 /// If possible, this returns a global path resolving to `def_id` that is visible
239 /// from at least one local module, and returns `true`. If the crate defining `def_id` is
240 /// declared with an `extern crate`, the path is guaranteed to use the `extern crate`.
241 fn try_print_visible_def_path(self, def_id: DefId) -> Result<(Self, bool), Self::Error> {
242 let mut callers = Vec::new();
243 self.try_print_visible_def_path_recur(def_id, &mut callers)
246 /// Does the work of `try_print_visible_def_path`, building the
247 /// full definition path recursively before attempting to
248 /// post-process it into the valid and visible version that
249 /// accounts for re-exports.
251 /// This method should only be called by itself or
252 /// `try_print_visible_def_path`.
254 /// `callers` is a chain of visible_parent's leading to `def_id`,
255 /// to support cycle detection during recursion.
256 fn try_print_visible_def_path_recur(
259 callers: &mut Vec<DefId>,
260 ) -> Result<(Self, bool), Self::Error> {
261 define_scoped_cx!(self);
263 debug!("try_print_visible_def_path: def_id={:?}", def_id);
265 // If `def_id` is a direct or injected extern crate, return the
266 // path to the crate followed by the path to the item within the crate.
267 if def_id.index == CRATE_DEF_INDEX {
268 let cnum = def_id.krate;
270 if cnum == LOCAL_CRATE {
271 return Ok((self.path_crate(cnum)?, true));
274 // In local mode, when we encounter a crate other than
275 // LOCAL_CRATE, execution proceeds in one of two ways:
277 // 1. For a direct dependency, where user added an
278 // `extern crate` manually, we put the `extern
279 // crate` as the parent. So you wind up with
280 // something relative to the current crate.
281 // 2. For an extern inferred from a path or an indirect crate,
282 // where there is no explicit `extern crate`, we just prepend
284 match self.tcx().extern_crate(def_id) {
285 Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
286 (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {
287 debug!("try_print_visible_def_path: def_id={:?}", def_id);
289 if !span.is_dummy() {
290 self.print_def_path(def_id, &[])?
292 self.path_crate(cnum)?
297 (ExternCrateSource::Path, LOCAL_CRATE) => {
298 debug!("try_print_visible_def_path: def_id={:?}", def_id);
299 return Ok((self.path_crate(cnum)?, true));
304 return Ok((self.path_crate(cnum)?, true));
309 if def_id.is_local() {
310 return Ok((self, false));
313 let visible_parent_map = self.tcx().visible_parent_map(LOCAL_CRATE);
315 let mut cur_def_key = self.tcx().def_key(def_id);
316 debug!("try_print_visible_def_path: cur_def_key={:?}", cur_def_key);
318 // For a constructor, we want the name of its parent rather than <unnamed>.
319 if let DefPathData::Ctor = cur_def_key.disambiguated_data.data {
324 .expect("`DefPathData::Ctor` / `VariantData` missing a parent"),
327 cur_def_key = self.tcx().def_key(parent);
330 let visible_parent = match visible_parent_map.get(&def_id).cloned() {
331 Some(parent) => parent,
332 None => return Ok((self, false)),
334 if callers.contains(&visible_parent) {
335 return Ok((self, false));
337 callers.push(visible_parent);
338 // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
339 // knowing ahead of time whether the entire path will succeed or not.
340 // To support printers that do not implement `PrettyPrinter`, a `Vec` or
341 // linked list on the stack would need to be built, before any printing.
342 match self.try_print_visible_def_path_recur(visible_parent, callers)? {
343 (cx, false) => return Ok((cx, false)),
344 (cx, true) => self = cx,
347 let actual_parent = self.tcx().parent(def_id);
349 "try_print_visible_def_path: visible_parent={:?} actual_parent={:?}",
350 visible_parent, actual_parent,
353 let mut data = cur_def_key.disambiguated_data.data;
355 "try_print_visible_def_path: data={:?} visible_parent={:?} actual_parent={:?}",
356 data, visible_parent, actual_parent,
360 // In order to output a path that could actually be imported (valid and visible),
361 // we need to handle re-exports correctly.
363 // For example, take `std::os::unix::process::CommandExt`, this trait is actually
364 // defined at `std::sys::unix::ext::process::CommandExt` (at time of writing).
366 // `std::os::unix` rexports the contents of `std::sys::unix::ext`. `std::sys` is
367 // private so the "true" path to `CommandExt` isn't accessible.
369 // In this case, the `visible_parent_map` will look something like this:
371 // (child) -> (parent)
372 // `std::sys::unix::ext::process::CommandExt` -> `std::sys::unix::ext::process`
373 // `std::sys::unix::ext::process` -> `std::sys::unix::ext`
374 // `std::sys::unix::ext` -> `std::os`
376 // This is correct, as the visible parent of `std::sys::unix::ext` is in fact
379 // When printing the path to `CommandExt` and looking at the `cur_def_key` that
380 // corresponds to `std::sys::unix::ext`, we would normally print `ext` and then go
381 // to the parent - resulting in a mangled path like
382 // `std::os::ext::process::CommandExt`.
384 // Instead, we must detect that there was a re-export and instead print `unix`
385 // (which is the name `std::sys::unix::ext` was re-exported as in `std::os`). To
386 // do this, we compare the parent of `std::sys::unix::ext` (`std::sys::unix`) with
387 // the visible parent (`std::os`). If these do not match, then we iterate over
388 // the children of the visible parent (as was done when computing
389 // `visible_parent_map`), looking for the specific child we currently have and then
390 // have access to the re-exported name.
391 DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
394 .item_children(visible_parent)
396 .find(|child| child.res.opt_def_id() == Some(def_id))
397 .map(|child| child.ident.name);
398 if let Some(reexport) = reexport {
402 // Re-exported `extern crate` (#43189).
403 DefPathData::CrateRoot => {
404 data = DefPathData::TypeNs(self.tcx().original_crate_name(def_id.krate));
408 debug!("try_print_visible_def_path: data={:?}", data);
410 Ok((self.path_append(Ok, &DisambiguatedDefPathData { data, disambiguator: 0 })?, true))
413 fn pretty_path_qualified(
416 trait_ref: Option<ty::TraitRef<'tcx>>,
417 ) -> Result<Self::Path, Self::Error> {
418 if trait_ref.is_none() {
419 // Inherent impls. Try to print `Foo::bar` for an inherent
420 // impl on `Foo`, but fallback to `<Foo>::bar` if self-type is
421 // anything other than a simple path.
431 return self_ty.print(self);
438 self.generic_delimiters(|mut cx| {
439 define_scoped_cx!(cx);
442 if let Some(trait_ref) = trait_ref {
443 p!(write(" as "), print(trait_ref.print_only_trait_path()));
449 fn pretty_path_append_impl(
451 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
453 trait_ref: Option<ty::TraitRef<'tcx>>,
454 ) -> Result<Self::Path, Self::Error> {
455 self = print_prefix(self)?;
457 self.generic_delimiters(|mut cx| {
458 define_scoped_cx!(cx);
461 if let Some(trait_ref) = trait_ref {
462 p!(print(trait_ref.print_only_trait_path()), write(" for "));
470 fn pretty_print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
471 define_scoped_cx!(self);
474 ty::Bool => p!(write("bool")),
475 ty::Char => p!(write("char")),
476 ty::Int(t) => p!(write("{}", t.name_str())),
477 ty::Uint(t) => p!(write("{}", t.name_str())),
478 ty::Float(t) => p!(write("{}", t.name_str())),
479 ty::RawPtr(ref tm) => {
483 hir::Mutability::Mut => "mut",
484 hir::Mutability::Not => "const",
489 ty::Ref(r, ty, mutbl) => {
491 if self.region_should_not_be_omitted(r) {
492 p!(print(r), write(" "));
494 p!(print(ty::TypeAndMut { ty, mutbl }))
496 ty::Never => p!(write("!")),
497 ty::Tuple(ref tys) => {
498 p!(write("("), comma_sep(tys.iter()));
504 ty::FnDef(def_id, substs) => {
505 let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
506 p!(print(sig), write(" {{"), print_value_path(def_id, substs), write("}}"));
508 ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
509 ty::Infer(infer_ty) => {
510 if let ty::TyVar(ty_vid) = infer_ty {
511 if let Some(name) = self.infer_ty_name(ty_vid) {
512 p!(write("{}", name))
514 p!(write("{}", infer_ty))
517 p!(write("{}", infer_ty))
520 ty::Error(_) => p!(write("[type error]")),
521 ty::Param(ref param_ty) => p!(write("{}", param_ty)),
522 ty::Bound(debruijn, bound_ty) => match bound_ty.kind {
523 ty::BoundTyKind::Anon => self.pretty_print_bound_var(debruijn, bound_ty.var)?,
524 ty::BoundTyKind::Param(p) => p!(write("{}", p)),
526 ty::Adt(def, substs) => {
527 p!(print_def_path(def.did, substs));
529 ty::Dynamic(data, r) => {
530 let print_r = self.region_should_not_be_omitted(r);
534 p!(write("dyn "), print(data));
536 p!(write(" + "), print(r), write(")"));
539 ty::Foreign(def_id) => {
540 p!(print_def_path(def_id, &[]));
542 ty::Projection(ref data) => p!(print(data)),
543 ty::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
544 ty::Opaque(def_id, substs) => {
545 // FIXME(eddyb) print this with `print_def_path`.
546 // We use verbose printing in 'NO_QUERIES' mode, to
547 // avoid needing to call `predicates_of`. This should
548 // only affect certain debug messages (e.g. messages printed
549 // from `rustc_middle::ty` during the computation of `tcx.predicates_of`),
550 // and should have no effect on any compiler output.
551 if self.tcx().sess.verbose() || NO_QUERIES.with(|q| q.get()) {
552 p!(write("Opaque({:?}, {:?})", def_id, substs));
556 return Ok(with_no_queries(|| {
557 let def_key = self.tcx().def_key(def_id);
558 if let Some(name) = def_key.disambiguated_data.data.get_opt_name() {
559 p!(write("{}", name));
560 // FIXME(eddyb) print this with `print_def_path`.
561 if !substs.is_empty() {
563 p!(generic_delimiters(|cx| cx.comma_sep(substs.iter())));
567 // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
568 // by looking up the projections associated with the def_id.
569 let bounds = self.tcx().predicates_of(def_id).instantiate(self.tcx(), substs);
571 let mut first = true;
572 let mut is_sized = false;
574 for predicate in bounds.predicates {
575 // Note: We can't use `to_opt_poly_trait_ref` here as `predicate`
576 // may contain unbound variables. We therefore do this manually.
578 // FIXME(lcnr): Find out why exactly this is the case :)
579 if let ty::PredicateAtom::Trait(pred, _) =
580 predicate.bound_atom(self.tcx()).skip_binder()
582 let trait_ref = ty::Binder::bind(pred.trait_ref);
583 // Don't print +Sized, but rather +?Sized if absent.
584 if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
590 write("{}", if first { " " } else { "+" }),
591 print(trait_ref.print_only_trait_path())
597 p!(write("{}?Sized", if first { " " } else { "+" }));
604 ty::Str => p!(write("str")),
605 ty::Generator(did, substs, movability) => {
607 hir::Movability::Movable => p!(write("[generator")),
608 hir::Movability::Static => p!(write("[static generator")),
611 // FIXME(eddyb) should use `def_span`.
612 if let Some(did) = did.as_local() {
613 let hir_id = self.tcx().hir().as_local_hir_id(did);
614 let span = self.tcx().hir().span(hir_id);
615 p!(write("@{}", self.tcx().sess.source_map().span_to_string(span)));
617 if substs.as_generator().is_valid() {
618 let upvar_tys = substs.as_generator().upvar_tys();
620 for (&var_id, upvar_ty) in self
622 .upvars_mentioned(did)
625 .flat_map(|v| v.keys())
628 p!(write("{}{}:", sep, self.tcx().hir().name(var_id)), print(upvar_ty));
633 p!(write("@{}", self.tcx().def_path_str(did)));
635 if substs.as_generator().is_valid() {
636 let upvar_tys = substs.as_generator().upvar_tys();
638 for (index, upvar_ty) in upvar_tys.enumerate() {
639 p!(write("{}{}:", sep, index), print(upvar_ty));
645 if substs.as_generator().is_valid() {
646 p!(write(" "), print(substs.as_generator().witness()));
651 ty::GeneratorWitness(types) => {
652 p!(in_binder(&types));
654 ty::Closure(did, substs) => {
655 p!(write("[closure"));
657 // FIXME(eddyb) should use `def_span`.
658 if let Some(did) = did.as_local() {
659 let hir_id = self.tcx().hir().as_local_hir_id(did);
660 if self.tcx().sess.opts.debugging_opts.span_free_formats {
661 p!(write("@"), print_def_path(did.to_def_id(), substs));
663 let span = self.tcx().hir().span(hir_id);
664 p!(write("@{}", self.tcx().sess.source_map().span_to_string(span)));
667 if substs.as_closure().is_valid() {
668 let upvar_tys = substs.as_closure().upvar_tys();
670 for (&var_id, upvar_ty) in self
672 .upvars_mentioned(did)
675 .flat_map(|v| v.keys())
678 p!(write("{}{}:", sep, self.tcx().hir().name(var_id)), print(upvar_ty));
683 p!(write("@{}", self.tcx().def_path_str(did)));
685 if substs.as_closure().is_valid() {
686 let upvar_tys = substs.as_closure().upvar_tys();
688 for (index, upvar_ty) in upvar_tys.enumerate() {
689 p!(write("{}{}:", sep, index), print(upvar_ty));
695 if self.tcx().sess.verbose() && substs.as_closure().is_valid() {
696 p!(write(" closure_kind_ty="), print(substs.as_closure().kind_ty()));
698 write(" closure_sig_as_fn_ptr_ty="),
699 print(substs.as_closure().sig_as_fn_ptr_ty())
705 ty::Array(ty, sz) => {
706 p!(write("["), print(ty), write("; "));
707 if self.tcx().sess.verbose() {
708 p!(write("{:?}", sz));
709 } else if let ty::ConstKind::Unevaluated(..) = sz.val {
710 // Do not try to evaluate unevaluated constants. If we are const evaluating an
711 // array length anon const, rustc will (with debug assertions) print the
712 // constant's path. Which will end up here again.
714 } else if let Some(n) = sz.val.try_to_bits(self.tcx().data_layout.pointer_size) {
716 } else if let ty::ConstKind::Param(param) = sz.val {
717 p!(write("{}", param));
723 ty::Slice(ty) => p!(write("["), print(ty), write("]")),
729 fn pretty_print_bound_var(
731 debruijn: ty::DebruijnIndex,
733 ) -> Result<(), Self::Error> {
734 if debruijn == ty::INNERMOST {
735 write!(self, "^{}", var.index())
737 write!(self, "^{}_{}", debruijn.index(), var.index())
741 fn infer_ty_name(&self, _: ty::TyVid) -> Option<String> {
745 fn pretty_print_dyn_existential(
747 predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
748 ) -> Result<Self::DynExistential, Self::Error> {
749 define_scoped_cx!(self);
751 // Generate the main trait ref, including associated types.
752 let mut first = true;
754 if let Some(principal) = predicates.principal() {
755 p!(print_def_path(principal.def_id, &[]));
757 let mut resugared = false;
759 // Special-case `Fn(...) -> ...` and resugar it.
760 let fn_trait_kind = self.tcx().fn_trait_kind_from_lang_item(principal.def_id);
761 if !self.tcx().sess.verbose() && fn_trait_kind.is_some() {
762 if let ty::Tuple(ref args) = principal.substs.type_at(0).kind {
763 let mut projections = predicates.projection_bounds();
764 if let (Some(proj), None) = (projections.next(), projections.next()) {
765 let tys: Vec<_> = args.iter().map(|k| k.expect_ty()).collect();
766 p!(pretty_fn_sig(&tys, false, proj.ty));
772 // HACK(eddyb) this duplicates `FmtPrinter`'s `path_generic_args`,
773 // in order to place the projections inside the `<...>`.
775 // Use a type that can't appear in defaults of type parameters.
776 let dummy_self = self.tcx().mk_ty_infer(ty::FreshTy(0));
777 let principal = principal.with_self_ty(self.tcx(), dummy_self);
779 let args = self.generic_args_to_print(
780 self.tcx().generics_of(principal.def_id),
784 // Don't print `'_` if there's no unerased regions.
785 let print_regions = args.iter().any(|arg| match arg.unpack() {
786 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
789 let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
790 GenericArgKind::Lifetime(_) => print_regions,
793 let mut projections = predicates.projection_bounds();
795 let arg0 = args.next();
796 let projection0 = projections.next();
797 if arg0.is_some() || projection0.is_some() {
798 let args = arg0.into_iter().chain(args);
799 let projections = projection0.into_iter().chain(projections);
801 p!(generic_delimiters(|mut cx| {
802 cx = cx.comma_sep(args)?;
803 if arg0.is_some() && projection0.is_some() {
806 cx.comma_sep(projections)
814 // FIXME(eddyb) avoid printing twice (needed to ensure
815 // that the auto traits are sorted *and* printed via cx).
816 let mut auto_traits: Vec<_> =
817 predicates.auto_traits().map(|did| (self.tcx().def_path_str(did), did)).collect();
819 // The auto traits come ordered by `DefPathHash`. While
820 // `DefPathHash` is *stable* in the sense that it depends on
821 // neither the host nor the phase of the moon, it depends
822 // "pseudorandomly" on the compiler version and the target.
824 // To avoid that causing instabilities in compiletest
825 // output, sort the auto-traits alphabetically.
828 for (_, def_id) in auto_traits {
834 p!(print_def_path(def_id, &[]));
845 ) -> Result<Self, Self::Error> {
846 define_scoped_cx!(self);
848 p!(write("("), comma_sep(inputs.iter().copied()));
850 if !inputs.is_empty() {
856 if !output.is_unit() {
857 p!(write(" -> "), print(output));
863 fn pretty_print_const(
865 ct: &'tcx ty::Const<'tcx>,
867 ) -> Result<Self::Const, Self::Error> {
868 define_scoped_cx!(self);
870 if self.tcx().sess.verbose() {
871 p!(write("Const({:?}: {:?})", ct.val, ct.ty));
875 macro_rules! print_underscore {
878 self = self.typed_value(
883 |this| this.print_type(ct.ty),
893 ty::ConstKind::Unevaluated(def, substs, promoted) => {
894 if let Some(promoted) = promoted {
895 p!(print_value_path(def.did, substs));
896 p!(write("::{:?}", promoted));
898 match self.tcx().def_kind(def.did) {
899 DefKind::Static | DefKind::Const | DefKind::AssocConst => {
900 p!(print_value_path(def.did, substs))
904 let span = self.tcx().def_span(def.did);
905 if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span)
907 p!(write("{}", snip))
918 ty::ConstKind::Infer(..) => print_underscore!(),
919 ty::ConstKind::Param(ParamConst { name, .. }) => p!(write("{}", name)),
920 ty::ConstKind::Value(value) => {
921 return self.pretty_print_const_value(value, ct.ty, print_ty);
924 ty::ConstKind::Bound(debruijn, bound_var) => {
925 self.pretty_print_bound_var(debruijn, bound_var)?
927 ty::ConstKind::Placeholder(placeholder) => p!(write("Placeholder({:?})", placeholder)),
928 ty::ConstKind::Error(_) => p!(write("[const error]")),
933 fn pretty_print_const_scalar(
938 ) -> Result<Self::Const, Self::Error> {
939 define_scoped_cx!(self);
941 match (scalar, &ty.kind) {
942 // Byte strings (&[u8; N])
950 ty::TyS { kind: ty::Uint(ast::UintTy::U8), .. },
953 ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw {
964 ) => match self.tcx().get_global_alloc(ptr.alloc_id) {
965 Some(GlobalAlloc::Memory(alloc)) => {
966 if let Ok(byte_str) = alloc.get_bytes(&self.tcx(), ptr, Size::from_bytes(*data))
968 p!(pretty_print_byte_str(byte_str))
970 p!(write("<too short allocation>"))
973 // FIXME: for statics and functions, we could in principle print more detail.
974 Some(GlobalAlloc::Static(def_id)) => p!(write("<static({:?})>", def_id)),
975 Some(GlobalAlloc::Function(_)) => p!(write("<function>")),
976 None => p!(write("<dangling pointer>")),
979 (Scalar::Raw { data: 0, .. }, ty::Bool) => p!(write("false")),
980 (Scalar::Raw { data: 1, .. }, ty::Bool) => p!(write("true")),
982 (Scalar::Raw { data, .. }, ty::Float(ast::FloatTy::F32)) => {
983 p!(write("{}f32", Single::from_bits(data)))
985 (Scalar::Raw { data, .. }, ty::Float(ast::FloatTy::F64)) => {
986 p!(write("{}f64", Double::from_bits(data)))
989 (Scalar::Raw { data, .. }, ty::Uint(ui)) => {
990 let size = Integer::from_attr(&self.tcx(), UnsignedInt(*ui)).size();
991 let int = ConstInt::new(data, size, false, ty.is_ptr_sized_integral());
992 if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
994 (Scalar::Raw { data, .. }, ty::Int(i)) => {
995 let size = Integer::from_attr(&self.tcx(), SignedInt(*i)).size();
996 let int = ConstInt::new(data, size, true, ty.is_ptr_sized_integral());
997 if print_ty { p!(write("{:#?}", int)) } else { p!(write("{:?}", int)) }
1000 (Scalar::Raw { data, .. }, ty::Char) if char::from_u32(data as u32).is_some() => {
1001 p!(write("{:?}", char::from_u32(data as u32).unwrap()))
1004 (Scalar::Raw { data, .. }, ty::RawPtr(_)) => {
1005 self = self.typed_value(
1007 write!(this, "0x{:x}", data)?;
1010 |this| this.print_type(ty),
1014 (Scalar::Ptr(ptr), ty::FnPtr(_)) => {
1015 // FIXME: this can ICE when the ptr is dangling or points to a non-function.
1016 // We should probably have a helper method to share code with the "Byte strings"
1017 // printing above (which also has to handle pointers to all sorts of things).
1018 let instance = self.tcx().global_alloc(ptr.alloc_id).unwrap_fn();
1019 self = self.typed_value(
1020 |this| this.print_value_path(instance.def_id(), instance.substs),
1021 |this| this.print_type(ty),
1025 // For function type zsts just printing the path is enough
1026 (Scalar::Raw { size: 0, .. }, ty::FnDef(d, s)) => p!(print_value_path(*d, s)),
1027 // Nontrivial types with scalar bit representation
1028 (Scalar::Raw { data, size }, _) => {
1029 let print = |mut this: Self| {
1031 write!(this, "transmute(())")?;
1033 write!(this, "transmute(0x{:01$x})", data, size as usize * 2)?;
1037 self = if print_ty {
1038 self.typed_value(print, |this| this.print_type(ty), ": ")?
1043 // Any pointer values not covered by a branch above
1044 (Scalar::Ptr(p), _) => {
1045 self = self.pretty_print_const_pointer(p, ty, print_ty)?;
1051 /// This is overridden for MIR printing because we only want to hide alloc ids from users, not
1052 /// from MIR where it is actually useful.
1053 fn pretty_print_const_pointer(
1058 ) -> Result<Self::Const, Self::Error> {
1062 this.write_str("&_")?;
1065 |this| this.print_type(ty),
1069 self.write_str("&_")?;
1074 fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
1075 define_scoped_cx!(self);
1077 for &c in byte_str {
1078 for e in std::ascii::escape_default(c) {
1079 self.write_char(e as char)?;
1086 fn pretty_print_const_value(
1088 ct: ConstValue<'tcx>,
1091 ) -> Result<Self::Const, Self::Error> {
1092 define_scoped_cx!(self);
1094 if self.tcx().sess.verbose() {
1095 p!(write("ConstValue({:?}: ", ct), print(ty), write(")"));
1099 let u8_type = self.tcx().types.u8;
1101 match (ct, &ty.kind) {
1102 // Byte/string slices, printed as (byte) string literals.
1104 ConstValue::Slice { data, start, end },
1105 ty::Ref(_, ty::TyS { kind: ty::Slice(t), .. }, _),
1106 ) if *t == u8_type => {
1107 // The `inspect` here is okay since we checked the bounds, and there are
1108 // no relocations (we have an active slice reference here). We don't use
1109 // this result to affect interpreter execution.
1110 let byte_str = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1111 self.pretty_print_byte_str(byte_str)
1114 ConstValue::Slice { data, start, end },
1115 ty::Ref(_, ty::TyS { kind: ty::Str, .. }, _),
1117 // The `inspect` here is okay since we checked the bounds, and there are no
1118 // relocations (we have an active `str` reference here). We don't use this
1119 // result to affect interpreter execution.
1120 let slice = data.inspect_with_uninit_and_ptr_outside_interpreter(start..end);
1121 let s = ::std::str::from_utf8(slice).expect("non utf8 str from miri");
1122 p!(write("{:?}", s));
1125 (ConstValue::ByRef { alloc, offset }, ty::Array(t, n)) if *t == u8_type => {
1126 let n = n.val.try_to_bits(self.tcx().data_layout.pointer_size).unwrap();
1127 // cast is ok because we already checked for pointer size (32 or 64 bit) above
1128 let n = Size::from_bytes(n);
1129 let ptr = Pointer::new(AllocId(0), offset);
1131 let byte_str = alloc.get_bytes(&self.tcx(), ptr, n).unwrap();
1133 p!(pretty_print_byte_str(byte_str));
1137 // Aggregates, printed as array/tuple/struct/variant construction syntax.
1139 // NB: the `has_param_types_or_consts` check ensures that we can use
1140 // the `destructure_const` query with an empty `ty::ParamEnv` without
1141 // introducing ICEs (e.g. via `layout_of`) from missing bounds.
1142 // E.g. `transmute([0usize; 2]): (u8, *mut T)` needs to know `T: Sized`
1143 // to be able to destructure the tuple into `(0u8, *mut T)
1145 // FIXME(eddyb) for `--emit=mir`/`-Z dump-mir`, we should provide the
1146 // correct `ty::ParamEnv` to allow printing *all* constant values.
1147 (_, ty::Array(..) | ty::Tuple(..) | ty::Adt(..)) if !ty.has_param_types_or_consts() => {
1148 let contents = self.tcx().destructure_const(
1149 ty::ParamEnv::reveal_all()
1150 .and(self.tcx().mk_const(ty::Const { val: ty::ConstKind::Value(ct), ty })),
1152 let fields = contents.fields.iter().copied();
1156 p!(write("["), comma_sep(fields), write("]"));
1159 p!(write("("), comma_sep(fields));
1160 if contents.fields.len() == 1 {
1165 ty::Adt(def, substs) if def.variants.is_empty() => {
1166 p!(print_value_path(def.did, substs));
1168 ty::Adt(def, substs) => {
1170 contents.variant.expect("destructed const of adt without variant id");
1171 let variant_def = &def.variants[variant_id];
1172 p!(print_value_path(variant_def.def_id, substs));
1174 match variant_def.ctor_kind {
1175 CtorKind::Const => {}
1177 p!(write("("), comma_sep(fields), write(")"));
1179 CtorKind::Fictive => {
1181 let mut first = true;
1182 for (field_def, field) in variant_def.fields.iter().zip(fields) {
1186 p!(write("{}: ", field_def.ident), print(field));
1193 _ => unreachable!(),
1199 (ConstValue::Scalar(scalar), _) => self.pretty_print_const_scalar(scalar, ty, print_ty),
1201 // FIXME(oli-obk): also pretty print arrays and other aggregate constants by reading
1202 // their fields instead of just dumping the memory.
1205 p!(write("{:?}", ct));
1207 p!(write(": "), print(ty));
1215 // HACK(eddyb) boxed to avoid moving around a large struct by-value.
1216 pub struct FmtPrinter<'a, 'tcx, F>(Box<FmtPrinterData<'a, 'tcx, F>>);
1218 pub struct FmtPrinterData<'a, 'tcx, F> {
1224 pub print_alloc_ids: bool,
1226 used_region_names: FxHashSet<Symbol>,
1227 region_index: usize,
1228 binder_depth: usize,
1230 pub region_highlight_mode: RegionHighlightMode,
1232 pub name_resolver: Option<Box<&'a dyn Fn(ty::sty::TyVid) -> Option<String>>>,
1235 impl<F> Deref for FmtPrinter<'a, 'tcx, F> {
1236 type Target = FmtPrinterData<'a, 'tcx, F>;
1237 fn deref(&self) -> &Self::Target {
1242 impl<F> DerefMut for FmtPrinter<'_, '_, F> {
1243 fn deref_mut(&mut self) -> &mut Self::Target {
1248 impl<F> FmtPrinter<'a, 'tcx, F> {
1249 pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
1250 FmtPrinter(Box::new(FmtPrinterData {
1254 in_value: ns == Namespace::ValueNS,
1255 print_alloc_ids: false,
1256 used_region_names: Default::default(),
1259 region_highlight_mode: RegionHighlightMode::default(),
1260 name_resolver: None,
1265 // HACK(eddyb) get rid of `def_path_str` and/or pass `Namespace` explicitly always
1266 // (but also some things just print a `DefId` generally so maybe we need this?)
1267 fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
1268 match tcx.def_key(def_id).disambiguated_data.data {
1269 DefPathData::TypeNs(..) | DefPathData::CrateRoot | DefPathData::ImplTrait => {
1273 DefPathData::ValueNs(..)
1274 | DefPathData::AnonConst
1275 | DefPathData::ClosureExpr
1276 | DefPathData::Ctor => Namespace::ValueNS,
1278 DefPathData::MacroNs(..) => Namespace::MacroNS,
1280 _ => Namespace::TypeNS,
1285 /// Returns a string identifying this `DefId`. This string is
1286 /// suitable for user output.
1287 pub fn def_path_str(self, def_id: DefId) -> String {
1288 self.def_path_str_with_substs(def_id, &[])
1291 pub fn def_path_str_with_substs(self, def_id: DefId, substs: &'t [GenericArg<'t>]) -> String {
1292 let ns = guess_def_namespace(self, def_id);
1293 debug!("def_path_str: def_id={:?}, ns={:?}", def_id, ns);
1294 let mut s = String::new();
1295 let _ = FmtPrinter::new(self, &mut s, ns).print_def_path(def_id, substs);
1300 impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
1301 fn write_str(&mut self, s: &str) -> fmt::Result {
1302 self.fmt.write_str(s)
1306 impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
1307 type Error = fmt::Error;
1312 type DynExistential = Self;
1315 fn tcx(&'a self) -> TyCtxt<'tcx> {
1322 substs: &'tcx [GenericArg<'tcx>],
1323 ) -> Result<Self::Path, Self::Error> {
1324 define_scoped_cx!(self);
1326 if substs.is_empty() {
1327 match self.try_print_visible_def_path(def_id)? {
1328 (cx, true) => return Ok(cx),
1329 (cx, false) => self = cx,
1333 let key = self.tcx.def_key(def_id);
1334 if let DefPathData::Impl = key.disambiguated_data.data {
1335 // Always use types for non-local impls, where types are always
1336 // available, and filename/line-number is mostly uninteresting.
1337 let use_types = !def_id.is_local() || {
1338 // Otherwise, use filename/line-number if forced.
1339 let force_no_types = FORCE_IMPL_FILENAME_LINE.with(|f| f.get());
1344 // If no type info is available, fall back to
1345 // pretty printing some span information. This should
1346 // only occur very early in the compiler pipeline.
1347 let parent_def_id = DefId { index: key.parent.unwrap(), ..def_id };
1348 let span = self.tcx.def_span(def_id);
1350 self = self.print_def_path(parent_def_id, &[])?;
1352 // HACK(eddyb) copy of `path_append` to avoid
1353 // constructing a `DisambiguatedDefPathData`.
1354 if !self.empty_path {
1355 write!(self, "::")?;
1357 write!(self, "<impl at {}>", self.tcx.sess.source_map().span_to_string(span))?;
1358 self.empty_path = false;
1364 self.default_print_def_path(def_id, substs)
1367 fn print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
1368 self.pretty_print_region(region)
1371 fn print_type(self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
1372 self.pretty_print_type(ty)
1375 fn print_dyn_existential(
1377 predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
1378 ) -> Result<Self::DynExistential, Self::Error> {
1379 self.pretty_print_dyn_existential(predicates)
1382 fn print_const(self, ct: &'tcx ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
1383 self.pretty_print_const(ct, true)
1386 fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
1387 self.empty_path = true;
1388 if cnum == LOCAL_CRATE {
1389 if self.tcx.sess.rust_2018() {
1390 // We add the `crate::` keyword on Rust 2018, only when desired.
1391 if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
1392 write!(self, "{}", kw::Crate)?;
1393 self.empty_path = false;
1397 write!(self, "{}", self.tcx.crate_name(cnum))?;
1398 self.empty_path = false;
1406 trait_ref: Option<ty::TraitRef<'tcx>>,
1407 ) -> Result<Self::Path, Self::Error> {
1408 self = self.pretty_path_qualified(self_ty, trait_ref)?;
1409 self.empty_path = false;
1413 fn path_append_impl(
1415 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1416 _disambiguated_data: &DisambiguatedDefPathData,
1418 trait_ref: Option<ty::TraitRef<'tcx>>,
1419 ) -> Result<Self::Path, Self::Error> {
1420 self = self.pretty_path_append_impl(
1422 cx = print_prefix(cx)?;
1432 self.empty_path = false;
1438 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1439 disambiguated_data: &DisambiguatedDefPathData,
1440 ) -> Result<Self::Path, Self::Error> {
1441 self = print_prefix(self)?;
1443 // Skip `::{{constructor}}` on tuple/unit structs.
1444 if let DefPathData::Ctor = disambiguated_data.data {
1448 // FIXME(eddyb) `name` should never be empty, but it
1449 // currently is for `extern { ... }` "foreign modules".
1450 let name = disambiguated_data.data.as_symbol();
1451 if name != kw::Invalid {
1452 if !self.empty_path {
1453 write!(self, "::")?;
1455 if Ident::with_dummy_span(name).is_raw_guess() {
1456 write!(self, "r#")?;
1458 write!(self, "{}", name)?;
1460 // FIXME(eddyb) this will print e.g. `{{closure}}#3`, but it
1461 // might be nicer to use something else, e.g. `{closure#3}`.
1462 let dis = disambiguated_data.disambiguator;
1463 let print_dis = disambiguated_data.data.get_opt_name().is_none()
1464 || dis != 0 && self.tcx.sess.verbose();
1466 write!(self, "#{}", dis)?;
1469 self.empty_path = false;
1475 fn path_generic_args(
1477 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
1478 args: &[GenericArg<'tcx>],
1479 ) -> Result<Self::Path, Self::Error> {
1480 self = print_prefix(self)?;
1482 // Don't print `'_` if there's no unerased regions.
1483 let print_regions = args.iter().any(|arg| match arg.unpack() {
1484 GenericArgKind::Lifetime(r) => *r != ty::ReErased,
1487 let args = args.iter().cloned().filter(|arg| match arg.unpack() {
1488 GenericArgKind::Lifetime(_) => print_regions,
1492 if args.clone().next().is_some() {
1494 write!(self, "::")?;
1496 self.generic_delimiters(|cx| cx.comma_sep(args))
1503 impl<F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
1504 fn infer_ty_name(&self, id: ty::TyVid) -> Option<String> {
1505 self.0.name_resolver.as_ref().and_then(|func| func(id))
1508 fn print_value_path(
1511 substs: &'tcx [GenericArg<'tcx>],
1512 ) -> Result<Self::Path, Self::Error> {
1513 let was_in_value = std::mem::replace(&mut self.in_value, true);
1514 self = self.print_def_path(def_id, substs)?;
1515 self.in_value = was_in_value;
1520 fn in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, Self::Error>
1522 T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
1524 self.pretty_in_binder(value)
1529 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1530 t: impl FnOnce(Self) -> Result<Self, Self::Error>,
1532 ) -> Result<Self::Const, Self::Error> {
1533 self.write_str("{")?;
1535 self.write_str(conversion)?;
1536 let was_in_value = std::mem::replace(&mut self.in_value, false);
1538 self.in_value = was_in_value;
1539 self.write_str("}")?;
1543 fn generic_delimiters(
1545 f: impl FnOnce(Self) -> Result<Self, Self::Error>,
1546 ) -> Result<Self, Self::Error> {
1549 let was_in_value = std::mem::replace(&mut self.in_value, false);
1550 let mut inner = f(self)?;
1551 inner.in_value = was_in_value;
1553 write!(inner, ">")?;
1557 fn region_should_not_be_omitted(&self, region: ty::Region<'_>) -> bool {
1558 let highlight = self.region_highlight_mode;
1559 if highlight.region_highlighted(region).is_some() {
1563 if self.tcx.sess.verbose() {
1567 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1570 ty::ReEarlyBound(ref data) => {
1571 data.name != kw::Invalid && data.name != kw::UnderscoreLifetime
1574 ty::ReLateBound(_, br)
1575 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1576 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1577 if let ty::BrNamed(_, name) = br {
1578 if name != kw::Invalid && name != kw::UnderscoreLifetime {
1583 if let Some((region, _)) = highlight.highlight_bound_region {
1592 ty::ReVar(_) if identify_regions => true,
1594 ty::ReVar(_) | ty::ReErased => false,
1596 ty::ReStatic | ty::ReEmpty(_) => true,
1600 fn pretty_print_const_pointer(
1605 ) -> Result<Self::Const, Self::Error> {
1606 let print = |mut this: Self| {
1607 define_scoped_cx!(this);
1608 if this.print_alloc_ids {
1609 p!(write("{:?}", p));
1616 self.typed_value(print, |this| this.print_type(ty), ": ")
1623 // HACK(eddyb) limited to `FmtPrinter` because of `region_highlight_mode`.
1624 impl<F: fmt::Write> FmtPrinter<'_, '_, F> {
1625 pub fn pretty_print_region(mut self, region: ty::Region<'_>) -> Result<Self, fmt::Error> {
1626 define_scoped_cx!(self);
1628 // Watch out for region highlights.
1629 let highlight = self.region_highlight_mode;
1630 if let Some(n) = highlight.region_highlighted(region) {
1631 p!(write("'{}", n));
1635 if self.tcx.sess.verbose() {
1636 p!(write("{:?}", region));
1640 let identify_regions = self.tcx.sess.opts.debugging_opts.identify_regions;
1642 // These printouts are concise. They do not contain all the information
1643 // the user might want to diagnose an error, but there is basically no way
1644 // to fit that into a short string. Hence the recommendation to use
1645 // `explain_region()` or `note_and_explain_region()`.
1647 ty::ReEarlyBound(ref data) => {
1648 if data.name != kw::Invalid {
1649 p!(write("{}", data.name));
1653 ty::ReLateBound(_, br)
1654 | ty::ReFree(ty::FreeRegion { bound_region: br, .. })
1655 | ty::RePlaceholder(ty::Placeholder { name: br, .. }) => {
1656 if let ty::BrNamed(_, name) = br {
1657 if name != kw::Invalid && name != kw::UnderscoreLifetime {
1658 p!(write("{}", name));
1663 if let Some((region, counter)) = highlight.highlight_bound_region {
1665 p!(write("'{}", counter));
1670 ty::ReVar(region_vid) if identify_regions => {
1671 p!(write("{:?}", region_vid));
1677 p!(write("'static"));
1680 ty::ReEmpty(ty::UniverseIndex::ROOT) => {
1681 p!(write("'<empty>"));
1684 ty::ReEmpty(ui) => {
1685 p!(write("'<empty:{:?}>", ui));
1696 // HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
1697 // `region_index` and `used_region_names`.
1698 impl<F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
1699 pub fn name_all_regions<T>(
1701 value: &ty::Binder<T>,
1702 ) -> Result<(Self, (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)), fmt::Error>
1704 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
1706 fn name_by_region_index(index: usize) -> Symbol {
1708 0 => Symbol::intern("'r"),
1709 1 => Symbol::intern("'s"),
1710 i => Symbol::intern(&format!("'t{}", i - 2)),
1714 // Replace any anonymous late-bound regions with named
1715 // variants, using new unique identifiers, so that we can
1716 // clearly differentiate between named and unnamed regions in
1717 // the output. We'll probably want to tweak this over time to
1718 // decide just how much information to give.
1719 if self.binder_depth == 0 {
1720 self.prepare_late_bound_region_info(value);
1723 let mut empty = true;
1724 let mut start_or_continue = |cx: &mut Self, start: &str, cont: &str| {
1737 define_scoped_cx!(self);
1739 let mut region_index = self.region_index;
1740 let new_value = self.tcx.replace_late_bound_regions(value, |br| {
1741 let _ = start_or_continue(&mut self, "for<", ", ");
1743 ty::BrNamed(_, name) => {
1744 let _ = write!(self, "{}", name);
1747 ty::BrAnon(_) | ty::BrEnv => {
1749 let name = name_by_region_index(region_index);
1751 if !self.used_region_names.contains(&name) {
1755 let _ = write!(self, "{}", name);
1756 ty::BrNamed(DefId::local(CRATE_DEF_INDEX), name)
1759 self.tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br))
1761 start_or_continue(&mut self, "", "> ")?;
1763 self.binder_depth += 1;
1764 self.region_index = region_index;
1765 Ok((self, new_value))
1768 pub fn pretty_in_binder<T>(self, value: &ty::Binder<T>) -> Result<Self, fmt::Error>
1770 T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
1772 let old_region_index = self.region_index;
1773 let (new, new_value) = self.name_all_regions(value)?;
1774 let mut inner = new_value.0.print(new)?;
1775 inner.region_index = old_region_index;
1776 inner.binder_depth -= 1;
1780 fn prepare_late_bound_region_info<T>(&mut self, value: &ty::Binder<T>)
1782 T: TypeFoldable<'tcx>,
1784 struct LateBoundRegionNameCollector<'a>(&'a mut FxHashSet<Symbol>);
1785 impl<'tcx> ty::fold::TypeVisitor<'tcx> for LateBoundRegionNameCollector<'_> {
1786 fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
1787 if let ty::ReLateBound(_, ty::BrNamed(_, name)) = *r {
1788 self.0.insert(name);
1790 r.super_visit_with(self)
1794 self.used_region_names.clear();
1795 let mut collector = LateBoundRegionNameCollector(&mut self.used_region_names);
1796 value.visit_with(&mut collector);
1797 self.region_index = 0;
1801 impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<T>
1803 T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
1806 type Error = P::Error;
1807 fn print(&self, cx: P) -> Result<Self::Output, Self::Error> {
1812 impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
1814 T: Print<'tcx, P, Output = P, Error = P::Error>,
1815 U: Print<'tcx, P, Output = P, Error = P::Error>,
1818 type Error = P::Error;
1819 fn print(&self, mut cx: P) -> Result<Self::Output, Self::Error> {
1820 define_scoped_cx!(cx);
1821 p!(print(self.0), write(": "), print(self.1));
1826 macro_rules! forward_display_to_print {
1828 $(impl fmt::Display for $ty {
1829 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1830 ty::tls::with(|tcx| {
1832 .expect("could not lift for printing")
1833 .print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
1841 macro_rules! define_print_and_forward_display {
1842 (($self:ident, $cx:ident): $($ty:ty $print:block)+) => {
1843 $(impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for $ty {
1845 type Error = fmt::Error;
1846 fn print(&$self, $cx: P) -> Result<Self::Output, Self::Error> {
1847 #[allow(unused_mut)]
1849 define_scoped_cx!($cx);
1851 #[allow(unreachable_code)]
1856 forward_display_to_print!($($ty),+);
1860 // HACK(eddyb) this is separate because `ty::RegionKind` doesn't need lifting.
1861 impl fmt::Display for ty::RegionKind {
1862 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1863 ty::tls::with(|tcx| {
1864 self.print(FmtPrinter::new(tcx, f, Namespace::TypeNS))?;
1870 /// Wrapper type for `ty::TraitRef` which opts-in to pretty printing only
1871 /// the trait path. That is, it will print `Trait<U>` instead of
1872 /// `<T as Trait<U>>`.
1873 #[derive(Copy, Clone, TypeFoldable, Lift)]
1874 pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
1876 impl fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
1877 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1878 fmt::Display::fmt(self, f)
1882 impl ty::TraitRef<'tcx> {
1883 pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
1884 TraitRefPrintOnlyTraitPath(self)
1888 impl ty::Binder<ty::TraitRef<'tcx>> {
1889 pub fn print_only_trait_path(self) -> ty::Binder<TraitRefPrintOnlyTraitPath<'tcx>> {
1890 self.map_bound(|tr| tr.print_only_trait_path())
1894 forward_display_to_print! {
1896 &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
1897 &'tcx ty::Const<'tcx>,
1899 // HACK(eddyb) these are exhaustive instead of generic,
1900 // because `for<'tcx>` isn't possible yet.
1901 ty::Binder<&'tcx ty::List<ty::ExistentialPredicate<'tcx>>>,
1902 ty::Binder<ty::TraitRef<'tcx>>,
1903 ty::Binder<TraitRefPrintOnlyTraitPath<'tcx>>,
1904 ty::Binder<ty::FnSig<'tcx>>,
1905 ty::Binder<ty::TraitPredicate<'tcx>>,
1906 ty::Binder<ty::SubtypePredicate<'tcx>>,
1907 ty::Binder<ty::ProjectionPredicate<'tcx>>,
1908 ty::Binder<ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
1909 ty::Binder<ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>,
1911 ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
1912 ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
1915 define_print_and_forward_display! {
1918 &'tcx ty::List<Ty<'tcx>> {
1919 p!(write("{{"), comma_sep(self.iter()), write("}}"))
1922 ty::TypeAndMut<'tcx> {
1923 p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
1926 ty::ExistentialTraitRef<'tcx> {
1927 // Use a type that can't appear in defaults of type parameters.
1928 let dummy_self = cx.tcx().mk_ty_infer(ty::FreshTy(0));
1929 let trait_ref = self.with_self_ty(cx.tcx(), dummy_self);
1930 p!(print(trait_ref.print_only_trait_path()))
1933 ty::ExistentialProjection<'tcx> {
1934 let name = cx.tcx().associated_item(self.item_def_id).ident;
1935 p!(write("{} = ", name), print(self.ty))
1938 ty::ExistentialPredicate<'tcx> {
1940 ty::ExistentialPredicate::Trait(x) => p!(print(x)),
1941 ty::ExistentialPredicate::Projection(x) => p!(print(x)),
1942 ty::ExistentialPredicate::AutoTrait(def_id) => {
1943 p!(print_def_path(def_id, &[]));
1949 p!(write("{}", self.unsafety.prefix_str()));
1951 if self.abi != Abi::Rust {
1952 p!(write("extern {} ", self.abi));
1955 p!(write("fn"), pretty_fn_sig(self.inputs(), self.c_variadic, self.output()));
1959 if cx.tcx().sess.verbose() {
1960 p!(write("{:?}", self));
1964 ty::TyVar(_) => p!(write("_")),
1965 ty::IntVar(_) => p!(write("{}", "{integer}")),
1966 ty::FloatVar(_) => p!(write("{}", "{float}")),
1967 ty::FreshTy(v) => p!(write("FreshTy({})", v)),
1968 ty::FreshIntTy(v) => p!(write("FreshIntTy({})", v)),
1969 ty::FreshFloatTy(v) => p!(write("FreshFloatTy({})", v))
1973 ty::TraitRef<'tcx> {
1974 p!(write("<{} as {}>", self.self_ty(), self.print_only_trait_path()))
1977 TraitRefPrintOnlyTraitPath<'tcx> {
1978 p!(print_def_path(self.0.def_id, self.0.substs));
1982 p!(write("{}", self.name))
1986 p!(write("{}", self.name))
1989 ty::SubtypePredicate<'tcx> {
1990 p!(print(self.a), write(" <: "), print(self.b))
1993 ty::TraitPredicate<'tcx> {
1994 p!(print(self.trait_ref.self_ty()), write(": "),
1995 print(self.trait_ref.print_only_trait_path()))
1998 ty::ProjectionPredicate<'tcx> {
1999 p!(print(self.projection_ty), write(" == "), print(self.ty))
2002 ty::ProjectionTy<'tcx> {
2003 p!(print_def_path(self.item_def_id, self.substs));
2008 ty::ClosureKind::Fn => p!(write("Fn")),
2009 ty::ClosureKind::FnMut => p!(write("FnMut")),
2010 ty::ClosureKind::FnOnce => p!(write("FnOnce")),
2014 ty::Predicate<'tcx> {
2016 &ty::PredicateKind::Atom(atom) => p!(print(atom)),
2017 ty::PredicateKind::ForAll(binder) => p!(print(binder)),
2021 ty::PredicateAtom<'tcx> {
2023 ty::PredicateAtom::Trait(ref data, constness) => {
2024 if let hir::Constness::Const = constness {
2025 p!(write("const "));
2029 ty::PredicateAtom::Subtype(predicate) => p!(print(predicate)),
2030 ty::PredicateAtom::RegionOutlives(predicate) => p!(print(predicate)),
2031 ty::PredicateAtom::TypeOutlives(predicate) => p!(print(predicate)),
2032 ty::PredicateAtom::Projection(predicate) => p!(print(predicate)),
2033 ty::PredicateAtom::WellFormed(arg) => p!(print(arg), write(" well-formed")),
2034 ty::PredicateAtom::ObjectSafe(trait_def_id) => {
2035 p!(write("the trait `"),
2036 print_def_path(trait_def_id, &[]),
2037 write("` is object-safe"))
2039 ty::PredicateAtom::ClosureKind(closure_def_id, _closure_substs, kind) => {
2040 p!(write("the closure `"),
2041 print_value_path(closure_def_id, &[]),
2042 write("` implements the trait `{}`", kind))
2044 ty::PredicateAtom::ConstEvaluatable(def, substs) => {
2045 p!(write("the constant `"),
2046 print_value_path(def.did, substs),
2047 write("` can be evaluated"))
2049 ty::PredicateAtom::ConstEquate(c1, c2) => {
2050 p!(write("the constant `"),
2052 write("` equals `"),
2060 match self.unpack() {
2061 GenericArgKind::Lifetime(lt) => p!(print(lt)),
2062 GenericArgKind::Type(ty) => p!(print(ty)),
2063 GenericArgKind::Const(ct) => p!(print(ct)),