src/librustc/util/ppaux.rs

   1 use crate::hir::def_id::DefId;
   2 use crate::hir::map::definitions::DefPathData;
   3 use crate::middle::region;
   4 use crate::ty::subst::{self, Kind, Subst, SubstsRef, UnpackedKind};
   5 use crate::ty::{BrAnon, BrEnv, BrFresh, BrNamed};
   6 use crate::ty::{Bool, Char, Adt};
   7 use crate::ty::{Error, Str, Array, Slice, Float, FnDef, FnPtr};
   8 use crate::ty::{Param, Bound, RawPtr, Ref, Never, Tuple};
   9 use crate::ty::{Closure, Generator, GeneratorWitness, Foreign, Projection, Opaque};
  10 use crate::ty::{Placeholder, UnnormalizedProjection, Dynamic, Int, Uint, Infer};
  11 use crate::ty::{self, ParamConst, Ty, TypeFoldable};
  12 use crate::ty::print::{PrintCx, Print};
  13 use crate::mir::interpret::ConstValue;
  14
  15 use std::cell::Cell;
  16 use std::fmt;
  17 use std::iter;
  18 use std::usize;
  19
  20 use rustc_target::spec::abi::Abi;
  21 use syntax::ast::CRATE_NODE_ID;
  22 use syntax::symbol::{Symbol, InternedString};
  23 use crate::hir;
  24
  25 /// The "region highlights" are used to control region printing during
  26 /// specific error messages. When a "region highlight" is enabled, it
  27 /// gives an alternate way to print specific regions. For now, we
  28 /// always print those regions using a number, so something like "`'0`".
  29 ///
  30 /// Regions not selected by the region highlight mode are presently
  31 /// unaffected.
  32 #[derive(Copy, Clone, Default)]
  33 pub struct RegionHighlightMode {
  34     /// If enabled, when we see the selected region, use "`'N`"
  35     /// instead of the ordinary behavior.
  36     highlight_regions: [Option<(ty::RegionKind, usize)>; 3],
  37
  38     /// If enabled, when printing a "free region" that originated from
  39     /// the given `ty::BoundRegion`, print it as "`'1`". Free regions that would ordinarily
  40     /// have names print as normal.
  41     ///
  42     /// This is used when you have a signature like `fn foo(x: &u32,
  43     /// y: &'a u32)` and we want to give a name to the region of the
  44     /// reference `x`.
  45     highlight_bound_region: Option<(ty::BoundRegion, usize)>,
  46 }
  47
  48 thread_local! {
  49     /// Mechanism for highlighting of specific regions for display in NLL region inference errors.
  50     /// Contains region to highlight and counter for number to use when highlighting.
  51     static REGION_HIGHLIGHT_MODE: Cell<RegionHighlightMode> =
  52         Cell::new(RegionHighlightMode::default())
  53 }
  54
  55 impl RegionHighlightMode {
  56     /// Reads and returns the current region highlight settings (accesses thread-local state).
  57     pub fn get() -> Self {
  58         REGION_HIGHLIGHT_MODE.with(|c| c.get())
  59     }
  60
  61     // Internal helper to update current settings during the execution of `op`.
  62     fn set<R>(
  63         old_mode: Self,
  64         new_mode: Self,
  65         op: impl FnOnce() -> R,
  66     ) -> R {
  67         REGION_HIGHLIGHT_MODE.with(|c| {
  68             c.set(new_mode);
  69             let result = op();
  70             c.set(old_mode);
  71             result
  72         })
  73     }
  74
  75     /// If `region` and `number` are both `Some`, invokes
  76     /// `highlighting_region`; otherwise, just invokes `op` directly.
  77     pub fn maybe_highlighting_region<R>(
  78         region: Option<ty::Region<'_>>,
  79         number: Option<usize>,
  80         op: impl FnOnce() -> R,
  81     ) -> R {
  82         if let Some(k) = region {
  83             if let Some(n) = number {
  84                 return Self::highlighting_region(k, n, op);
  85             }
  86         }
  87
  88         op()
  89     }
  90
  91     /// During the execution of `op`, highlights the region inference
  92     /// variable `vid` as `'N`. We can only highlight one region `vid`
  93     /// at a time.
  94     pub fn highlighting_region<R>(
  95         region: ty::Region<'_>,
  96         number: usize,
  97         op: impl FnOnce() -> R,
  98     ) -> R {
  99         let old_mode = Self::get();
 100         let mut new_mode = old_mode;
 101         let first_avail_slot = new_mode.highlight_regions.iter_mut()
 102             .filter(|s| s.is_none())
 103             .next()
 104             .unwrap_or_else(|| {
 105                 panic!(
 106                     "can only highlight {} placeholders at a time",
 107                     old_mode.highlight_regions.len(),
 108                 )
 109             });
 110         *first_avail_slot = Some((*region, number));
 111         Self::set(old_mode, new_mode, op)
 112     }
 113
 114     /// Convenience wrapper for `highlighting_region`.
 115     pub fn highlighting_region_vid<R>(
 116         vid: ty::RegionVid,
 117         number: usize,
 118         op: impl FnOnce() -> R,
 119     ) -> R {
 120         Self::highlighting_region(&ty::ReVar(vid), number, op)
 121     }
 122
 123     /// Returns `Some(n)` with the number to use for the given region, if any.
 124     fn region_highlighted(&self, region: ty::Region<'_>) -> Option<usize> {
 125         Self::get()
 126             .highlight_regions
 127             .iter()
 128             .filter_map(|h| match h {
 129                 Some((r, n)) if r == region => Some(*n),
 130                 _ => None,
 131             })
 132             .next()
 133     }
 134
 135     /// During the execution of `op`, highlight the given bound
 136     /// region. We can only highlight one bound region at a time. See
 137     /// the field `highlight_bound_region` for more detailed notes.
 138     pub fn highlighting_bound_region<R>(
 139         br: ty::BoundRegion,
 140         number: usize,
 141         op: impl FnOnce() -> R,
 142     ) -> R {
 143         let old_mode = Self::get();
 144         assert!(old_mode.highlight_bound_region.is_none());
 145         Self::set(
 146             old_mode,
 147             Self {
 148                 highlight_bound_region: Some((br, number)),
 149                 ..old_mode
 150             },
 151             op,
 152         )
 153     }
 154
 155     /// Returns `Some(N)` if the placeholder `p` is highlighted to print as "`'N`".
 156     pub fn placeholder_highlight(&self, p: ty::PlaceholderRegion) -> Option<usize> {
 157         self.region_highlighted(&ty::RePlaceholder(p))
 158     }
 159 }
 160
 161 macro_rules! gen_display_debug_body {
 162     ( $with:path ) => {
 163         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 164             PrintCx::with(|mut cx| {
 165                 $with(&cx.tcx.lift(self).expect("could not lift for printing"), f, &mut cx)
 166             })
 167         }
 168     };
 169 }
 170 macro_rules! gen_display_debug {
 171     ( ($($x:tt)+) $target:ty, display yes ) => {
 172         impl<$($x)+> fmt::Display for $target {
 173             gen_display_debug_body! { Print::print_display }
 174         }
 175     };
 176     ( () $target:ty, display yes ) => {
 177         impl fmt::Display for $target {
 178             gen_display_debug_body! { Print::print_display }
 179         }
 180     };
 181     ( ($($x:tt)+) $target:ty, debug yes ) => {
 182         impl<$($x)+> fmt::Debug for $target {
 183             gen_display_debug_body! { Print::print_debug }
 184         }
 185     };
 186     ( () $target:ty, debug yes ) => {
 187         impl fmt::Debug for $target {
 188             gen_display_debug_body! { Print::print_debug }
 189         }
 190     };
 191     ( $generic:tt $target:ty, $t:ident no ) => {};
 192 }
 193 macro_rules! gen_print_impl {
 194     ( ($($x:tt)+) $target:ty, ($self:ident, $f:ident, $cx:ident) $disp:block $dbg:block ) => {
 195         impl<$($x)+> Print<'tcx> for $target {
 196             fn print<F: fmt::Write>(
 197                 &$self,
 198                 $f: &mut F,
 199                 $cx: &mut PrintCx<'_, '_, 'tcx>,
 200             ) -> fmt::Result {
 201                 if $cx.is_debug $dbg
 202                 else $disp
 203             }
 204         }
 205     };
 206     ( () $target:ty, ($self:ident, $f:ident, $cx:ident) $disp:block $dbg:block ) => {
 207         impl Print<'tcx> for $target {
 208             fn print<F: fmt::Write>(
 209                 &$self,
 210                 $f: &mut F,
 211                 $cx: &mut PrintCx<'_, '_, 'tcx>,
 212             ) -> fmt::Result {
 213                 if $cx.is_debug $dbg
 214                 else $disp
 215             }
 216         }
 217     };
 218     ( $generic:tt $target:ty,
 219       $vars:tt $gendisp:ident $disp:block $gendbg:ident $dbg:block ) => {
 220         gen_print_impl! { $generic $target, $vars $disp $dbg }
 221         gen_display_debug! { $generic $target, display $gendisp }
 222         gen_display_debug! { $generic $target, debug $gendbg }
 223     }
 224 }
 225 macro_rules! define_print {
 226     ( $generic:tt $target:ty,
 227       $vars:tt { display $disp:block debug $dbg:block } ) => {
 228         gen_print_impl! { $generic $target, $vars yes $disp yes $dbg }
 229     };
 230     ( $generic:tt $target:ty,
 231       $vars:tt { debug $dbg:block display $disp:block } ) => {
 232         gen_print_impl! { $generic $target, $vars yes $disp yes $dbg }
 233     };
 234     ( $generic:tt $target:ty,
 235       $vars:tt { debug $dbg:block } ) => {
 236         gen_print_impl! { $generic $target, $vars no {
 237             bug!(concat!("display not implemented for ", stringify!($target)));
 238         } yes $dbg }
 239     };
 240     ( $generic:tt $target:ty,
 241       ($self:ident, $f:ident, $cx:ident) { display $disp:block } ) => {
 242         gen_print_impl! { $generic $target, ($self, $f, $cx) yes $disp no {
 243             write!($f, "{:?}", $self)
 244         } }
 245     };
 246 }
 247 macro_rules! define_print_multi {
 248     ( [ $($generic:tt $target:ty),* ] $vars:tt $def:tt ) => {
 249         $(define_print! { $generic $target, $vars $def })*
 250     };
 251 }
 252 macro_rules! print_inner {
 253     ( $f:expr, $cx:expr, write ($($data:expr),+) ) => {
 254         write!($f, $($data),+)
 255     };
 256     ( $f:expr, $cx:expr, $kind:ident ($data:expr) ) => {
 257         $data.$kind($f, $cx)
 258     };
 259 }
 260 macro_rules! print {
 261     ( $f:expr, $cx:expr $(, $kind:ident $data:tt)+ ) => {
 262         Ok(())$(.and_then(|_| print_inner!($f, $cx, $kind $data)))+
 263     };
 264 }
 265
 266 impl PrintCx<'a, 'gcx, 'tcx> {
 267     fn fn_sig<F: fmt::Write>(&mut self,
 268                              f: &mut F,
 269                              inputs: &[Ty<'tcx>],
 270                              c_variadic: bool,
 271                              output: Ty<'tcx>)
 272                              -> fmt::Result {
 273         write!(f, "(")?;
 274         let mut inputs = inputs.iter();
 275         if let Some(&ty) = inputs.next() {
 276             print!(f, self, print_display(ty))?;
 277             for &ty in inputs {
 278                 print!(f, self, write(", "), print_display(ty))?;
 279             }
 280             if c_variadic {
 281                 write!(f, ", ...")?;
 282             }
 283         }
 284         write!(f, ")")?;
 285         if !output.is_unit() {
 286             print!(f, self, write(" -> "), print_display(output))?;
 287         }
 288
 289         Ok(())
 290     }
 291
 292     fn parameterized<F: fmt::Write>(
 293         &mut self,
 294         f: &mut F,
 295         mut def_id: DefId,
 296         substs: SubstsRef<'tcx>,
 297         projections: impl Iterator<Item = ty::ExistentialProjection<'tcx>>,
 298     ) -> fmt::Result {
 299         let mut key = self.tcx.def_key(def_id);
 300         let is_value_ns = match key.disambiguated_data.data {
 301             DefPathData::ValueNs(_) |
 302             DefPathData::EnumVariant(_) => true,
 303
 304             // Skip `StructCtor` so that `Struct::<T>` will be printed,
 305             // instead of the less pretty `Struct<T>::{{constructor}}`.
 306             DefPathData::StructCtor => {
 307                 def_id.index = key.parent.unwrap();
 308                 key = self.tcx.def_key(def_id);
 309                 true
 310             }
 311
 312             _ => false,
 313         };
 314
 315         let generics = self.tcx.generics_of(def_id);
 316
 317         if let Some(parent_def_id) = generics.parent {
 318             assert_eq!(parent_def_id, DefId { index: key.parent.unwrap(), ..def_id });
 319
 320             let parent_generics = self.tcx.generics_of(parent_def_id);
 321             let parent_has_own_self =
 322                 parent_generics.has_self && parent_generics.parent_count == 0;
 323             if parent_has_own_self {
 324                 print!(f, self, write("<"), print_display(substs.type_at(0)), write(" as "))?;
 325             }
 326             self.parameterized(f, parent_def_id, substs, iter::empty())?;
 327             if parent_has_own_self {
 328                 write!(f, ">")?;
 329             }
 330
 331             write!(f, "::{}", key.disambiguated_data.data.as_interned_str())?;
 332         } else {
 333             // Try to print `impl`s more like how you'd refer to their associated items.
 334             if let DefPathData::Impl = key.disambiguated_data.data {
 335                 if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
 336                     // HACK(eddyb) this is in lieu of more specific disambiguation.
 337                     print!(f, self, write("{}", self.tcx.item_path_str(def_id)))?;
 338
 339                     let trait_ref = trait_ref.subst(self.tcx, substs);
 340                     print!(f, self, print_debug(trait_ref))?;
 341                 } else {
 342                     let self_ty = self.tcx.type_of(def_id).subst(self.tcx, substs);
 343                     // FIXME(eddyb) omit the <> where possible.
 344                     print!(f, self, write("<"), print(self_ty), write(">"))?;
 345                 }
 346                 return Ok(());
 347             }
 348
 349             print!(f, self, write("{}", self.tcx.item_path_str(def_id)))?;
 350         }
 351
 352         let mut empty = true;
 353         let mut start_or_continue = |f: &mut F, start: &str, cont: &str| {
 354             if empty {
 355                 empty = false;
 356                 write!(f, "{}", start)
 357             } else {
 358                 write!(f, "{}", cont)
 359             }
 360         };
 361
 362         let start = if is_value_ns { "::<" } else { "<" };
 363
 364         let has_own_self = generics.has_self && generics.parent_count == 0;
 365         let params = &generics.params[has_own_self as usize..];
 366
 367         // Don't print any regions if they're all erased.
 368         let print_regions = params.iter().any(|param| {
 369             match substs[param.index as usize].unpack() {
 370                 UnpackedKind::Lifetime(r) => *r != ty::ReErased,
 371                 _ => false,
 372             }
 373         });
 374
 375         // Don't print args that are the defaults of their respective parameters.
 376         let num_supplied_defaults = if self.is_verbose {
 377             0
 378         } else {
 379             params.iter().rev().take_while(|param| {
 380                 match param.kind {
 381                     ty::GenericParamDefKind::Lifetime => false,
 382                     ty::GenericParamDefKind::Type { has_default, .. } => {
 383                         has_default && substs[param.index as usize] == Kind::from(
 384                             self.tcx.type_of(param.def_id).subst(self.tcx, substs)
 385                         )
 386                     }
 387                     ty::GenericParamDefKind::Const => false, // FIXME(const_generics:defaults)
 388                 }
 389             }).count()
 390         };
 391
 392         for param in &params[..params.len() - num_supplied_defaults] {
 393             match substs[param.index as usize].unpack() {
 394                 UnpackedKind::Lifetime(region) => {
 395                     if !print_regions {
 396                         continue;
 397                     }
 398                     start_or_continue(f, start, ", ")?;
 399                     if self.is_verbose {
 400                         write!(f, "{:?}", region)?;
 401                     } else {
 402                         let s = region.print_display_to_string(self);
 403                         if s.is_empty() {
 404                             // This happens when the value of the region
 405                             // parameter is not easily serialized. This may be
 406                             // because the user omitted it in the first place,
 407                             // or because it refers to some block in the code,
 408                             // etc. I'm not sure how best to serialize this.
 409                             write!(f, "'_")?;
 410                         } else {
 411                             write!(f, "{}", s)?;
 412                         }
 413                     }
 414                 }
 415                 UnpackedKind::Type(ty) => {
 416                     start_or_continue(f, start, ", ")?;
 417                     ty.print_display(f, self)?;
 418                 }
 419                 UnpackedKind::Const(ct) => {
 420                     start_or_continue(f, start, ", ")?;
 421                     ct.print_display(f, self)?;
 422                 }
 423             }
 424         }
 425
 426         for projection in projections {
 427             start_or_continue(f, start, ", ")?;
 428             print!(f, self,
 429                     write("{}=",
 430                             self.tcx.associated_item(projection.item_def_id).ident),
 431                     print_display(projection.ty))?;
 432         }
 433
 434         start_or_continue(f, "", ">")
 435     }
 436
 437     fn in_binder<T, F>(&mut self, f: &mut F, value: &ty::Binder<T>) -> fmt::Result
 438         where T: Print<'tcx> + TypeFoldable<'tcx>, F: fmt::Write
 439     {
 440         fn name_by_region_index(index: usize) -> InternedString {
 441             match index {
 442                 0 => Symbol::intern("'r"),
 443                 1 => Symbol::intern("'s"),
 444                 i => Symbol::intern(&format!("'t{}", i-2)),
 445             }.as_interned_str()
 446         }
 447
 448         // Replace any anonymous late-bound regions with named
 449         // variants, using gensym'd identifiers, so that we can
 450         // clearly differentiate between named and unnamed regions in
 451         // the output. We'll probably want to tweak this over time to
 452         // decide just how much information to give.
 453         if self.binder_depth == 0 {
 454             self.prepare_late_bound_region_info(value);
 455         }
 456
 457         let mut empty = true;
 458         let mut start_or_continue = |f: &mut F, start: &str, cont: &str| {
 459             if empty {
 460                 empty = false;
 461                 write!(f, "{}", start)
 462             } else {
 463                 write!(f, "{}", cont)
 464             }
 465         };
 466
 467         let old_region_index = self.region_index;
 468         let mut region_index = old_region_index;
 469         let new_value = self.tcx.replace_late_bound_regions(value, |br| {
 470             let _ = start_or_continue(f, "for<", ", ");
 471             let br = match br {
 472                 ty::BrNamed(_, name) => {
 473                     let _ = write!(f, "{}", name);
 474                     br
 475                 }
 476                 ty::BrAnon(_) |
 477                 ty::BrFresh(_) |
 478                 ty::BrEnv => {
 479                     let name = loop {
 480                         let name = name_by_region_index(region_index);
 481                         region_index += 1;
 482                         if !self.is_name_used(&name) {
 483                             break name;
 484                         }
 485                     };
 486                     let _ = write!(f, "{}", name);
 487                     ty::BrNamed(self.tcx.hir().local_def_id(CRATE_NODE_ID), name)
 488                 }
 489             };
 490             self.tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br))
 491         }).0;
 492         start_or_continue(f, "", "> ")?;
 493
 494         // Push current state to gcx, and restore after writing new_value.
 495         self.binder_depth += 1;
 496         self.region_index = region_index;
 497         let result = new_value.print_display(f, self);
 498         self.region_index = old_region_index;
 499         self.binder_depth -= 1;
 500         result
 501     }
 502
 503     fn is_name_used(&self, name: &InternedString) -> bool {
 504         match self.used_region_names {
 505             Some(ref names) => names.contains(name),
 506             None => false,
 507         }
 508     }
 509 }
 510
 511 pub fn parameterized<F: fmt::Write>(f: &mut F, did: DefId, substs: SubstsRef<'_>) -> fmt::Result {
 512     PrintCx::with(|mut cx| {
 513         let substs = cx.tcx.lift(&substs).expect("could not lift for printing");
 514         cx.parameterized(f, did, substs, iter::empty())
 515     })
 516 }
 517
 518 impl<'a, 'tcx, T: Print<'tcx>> Print<'tcx> for &'a T {
 519     fn print<F: fmt::Write>(&self, f: &mut F, cx: &mut PrintCx<'_, '_, 'tcx>) -> fmt::Result {
 520         (*self).print(f, cx)
 521     }
 522 }
 523
 524 define_print! {
 525     ('tcx) &'tcx ty::List<ty::ExistentialPredicate<'tcx>>, (self, f, cx) {
 526         display {
 527             // Generate the main trait ref, including associated types.
 528             let mut first = true;
 529
 530             if let Some(principal) = self.principal() {
 531                 let mut resugared_principal = false;
 532
 533                 // Special-case `Fn(...) -> ...` and resugar it.
 534                 if !cx.is_verbose && cx.tcx.lang_items().fn_trait_kind(principal.def_id).is_some() {
 535                     if let Tuple(ref args) = principal.substs.type_at(0).sty {
 536                         let mut projections = self.projection_bounds();
 537                         if let (Some(proj), None) = (projections.next(), projections.next()) {
 538                             print!(f, cx, write("{}", cx.tcx.item_path_str(principal.def_id)))?;
 539                             cx.fn_sig(f, args, false, proj.ty)?;
 540                             resugared_principal = true;
 541                         }
 542                     }
 543                 }
 544
 545                 if !resugared_principal {
 546                     // Use a type that can't appear in defaults of type parameters.
 547                     let dummy_self = cx.tcx.mk_infer(ty::FreshTy(0));
 548                     let principal = principal.with_self_ty(cx.tcx, dummy_self);
 549                     cx.parameterized(
 550                         f,
 551                         principal.def_id,
 552                         principal.substs,
 553                         self.projection_bounds(),
 554                     )?;
 555                 }
 556                 first = false;
 557             }
 558
 559             // Builtin bounds.
 560             let mut auto_traits: Vec<_> = self.auto_traits().map(|did| {
 561                 cx.tcx.item_path_str(did)
 562             }).collect();
 563
 564             // The auto traits come ordered by `DefPathHash`. While
 565             // `DefPathHash` is *stable* in the sense that it depends on
 566             // neither the host nor the phase of the moon, it depends
 567             // "pseudorandomly" on the compiler version and the target.
 568             //
 569             // To avoid that causing instabilities in compiletest
 570             // output, sort the auto-traits alphabetically.
 571             auto_traits.sort();
 572
 573             for auto_trait in auto_traits {
 574                 if !first {
 575                     write!(f, " + ")?;
 576                 }
 577                 first = false;
 578
 579                 write!(f, "{}", auto_trait)?;
 580             }
 581
 582             Ok(())
 583         }
 584     }
 585 }
 586
 587 impl fmt::Debug for ty::GenericParamDef {
 588     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 589         let type_name = match self.kind {
 590             ty::GenericParamDefKind::Lifetime => "Lifetime",
 591             ty::GenericParamDefKind::Type { .. } => "Type",
 592             ty::GenericParamDefKind::Const => "Const",
 593         };
 594         write!(f, "{}({}, {:?}, {})",
 595                type_name,
 596                self.name,
 597                self.def_id,
 598                self.index)
 599     }
 600 }
 601
 602 impl fmt::Debug for ty::TraitDef {
 603     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 604         PrintCx::with(|cx| {
 605             write!(f, "{}", cx.tcx.item_path_str(self.def_id))
 606         })
 607     }
 608 }
 609
 610 impl fmt::Debug for ty::AdtDef {
 611     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 612         PrintCx::with(|cx| {
 613             write!(f, "{}", cx.tcx.item_path_str(self.did))
 614         })
 615     }
 616 }
 617
 618 impl<'tcx> fmt::Debug for ty::ClosureUpvar<'tcx> {
 619     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 620         write!(f, "ClosureUpvar({:?},{:?})",
 621                self.def,
 622                self.ty)
 623     }
 624 }
 625
 626 impl fmt::Debug for ty::UpvarId {
 627     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 628         write!(f, "UpvarId({:?};`{}`;{:?})",
 629                self.var_path.hir_id,
 630                PrintCx::with(|cx| {
 631                     cx.tcx.hir().name_by_hir_id(self.var_path.hir_id)
 632                }),
 633                self.closure_expr_id)
 634     }
 635 }
 636
 637 impl<'tcx> fmt::Debug for ty::UpvarBorrow<'tcx> {
 638     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 639         write!(f, "UpvarBorrow({:?}, {:?})",
 640                self.kind, self.region)
 641     }
 642 }
 643
 644 define_print! {
 645     ('tcx) &'tcx ty::List<Ty<'tcx>>, (self, f, cx) {
 646         display {
 647             write!(f, "{{")?;
 648             let mut tys = self.iter();
 649             if let Some(&ty) = tys.next() {
 650                 print!(f, cx, print(ty))?;
 651                 for &ty in tys {
 652                     print!(f, cx, write(", "), print(ty))?;
 653                 }
 654             }
 655             write!(f, "}}")
 656         }
 657     }
 658 }
 659
 660 define_print! {
 661     ('tcx) ty::TypeAndMut<'tcx>, (self, f, cx) {
 662         display {
 663             print!(f, cx,
 664                    write("{}", if self.mutbl == hir::MutMutable { "mut " } else { "" }),
 665                    print(self.ty))
 666         }
 667     }
 668 }
 669
 670 define_print! {
 671     ('tcx) ty::ExistentialTraitRef<'tcx>, (self, f, cx) {
 672         display {
 673             let dummy_self = cx.tcx.mk_infer(ty::FreshTy(0));
 674
 675             let trait_ref = *ty::Binder::bind(*self)
 676                 .with_self_ty(cx.tcx, dummy_self)
 677                 .skip_binder();
 678             cx.parameterized(f, trait_ref.def_id, trait_ref.substs, iter::empty())
 679         }
 680         debug {
 681             self.print_display(f, cx)
 682         }
 683     }
 684 }
 685
 686 define_print! {
 687     ('tcx) ty::adjustment::Adjustment<'tcx>, (self, f, cx) {
 688         debug {
 689             print!(f, cx, write("{:?} -> ", self.kind), print(self.target))
 690         }
 691     }
 692 }
 693
 694 define_print! {
 695     () ty::BoundRegion, (self, f, cx) {
 696         display {
 697             if cx.is_verbose {
 698                 return self.print_debug(f, cx);
 699             }
 700
 701             if let BrNamed(_, name) = *self {
 702                 if name != "" && name != "'_" {
 703                     return write!(f, "{}", name);
 704                 }
 705             }
 706
 707             let highlight = RegionHighlightMode::get();
 708             if let Some((region, counter)) = highlight.highlight_bound_region {
 709                 if *self == region {
 710                     return write!(f, "'{}", counter);
 711                 }
 712             }
 713
 714             Ok(())
 715         }
 716         debug {
 717             return match *self {
 718                 BrAnon(n) => write!(f, "BrAnon({:?})", n),
 719                 BrFresh(n) => write!(f, "BrFresh({:?})", n),
 720                 BrNamed(did, name) => {
 721                     write!(f, "BrNamed({:?}:{:?}, {})",
 722                            did.krate, did.index, name)
 723                 }
 724                 BrEnv => write!(f, "BrEnv"),
 725             };
 726         }
 727     }
 728 }
 729
 730 define_print! {
 731     () ty::PlaceholderRegion, (self, f, cx) {
 732         display {
 733             if cx.is_verbose {
 734                 return self.print_debug(f, cx);
 735             }
 736
 737             let highlight = RegionHighlightMode::get();
 738             if let Some(counter) = highlight.placeholder_highlight(*self) {
 739                 return write!(f, "'{}", counter);
 740             }
 741
 742             write!(f, "{}", self.name)
 743         }
 744     }
 745 }
 746
 747 define_print! {
 748     () ty::RegionKind, (self, f, cx) {
 749         display {
 750             if cx.is_verbose {
 751                 return self.print_debug(f, cx);
 752             }
 753
 754             // Watch out for region highlights.
 755             if let Some(n) = RegionHighlightMode::get().region_highlighted(self) {
 756                 return write!(f, "'{:?}", n);
 757             }
 758
 759             // These printouts are concise.  They do not contain all the information
 760             // the user might want to diagnose an error, but there is basically no way
 761             // to fit that into a short string.  Hence the recommendation to use
 762             // `explain_region()` or `note_and_explain_region()`.
 763             match *self {
 764                 ty::ReEarlyBound(ref data) => {
 765                     if data.name != "'_" {
 766                         write!(f, "{}", data.name)
 767                     } else {
 768                         Ok(())
 769                     }
 770                 }
 771                 ty::ReLateBound(_, br) |
 772                 ty::ReFree(ty::FreeRegion { bound_region: br, .. }) => {
 773                     write!(f, "{}", br)
 774                 }
 775                 ty::RePlaceholder(p) => {
 776                     write!(f, "{}", p)
 777                 }
 778                 ty::ReScope(scope) if cx.identify_regions => {
 779                     match scope.data {
 780                         region::ScopeData::Node =>
 781                             write!(f, "'{}s", scope.item_local_id().as_usize()),
 782                         region::ScopeData::CallSite =>
 783                             write!(f, "'{}cs", scope.item_local_id().as_usize()),
 784                         region::ScopeData::Arguments =>
 785                             write!(f, "'{}as", scope.item_local_id().as_usize()),
 786                         region::ScopeData::Destruction =>
 787                             write!(f, "'{}ds", scope.item_local_id().as_usize()),
 788                         region::ScopeData::Remainder(first_statement_index) => write!(
 789                             f,
 790                             "'{}_{}rs",
 791                             scope.item_local_id().as_usize(),
 792                             first_statement_index.index()
 793                         ),
 794                     }
 795                 }
 796                 ty::ReVar(region_vid) if cx.identify_regions => {
 797                     write!(f, "{:?}", region_vid)
 798                 }
 799                 ty::ReVar(region_vid) => {
 800                     write!(f, "{}", region_vid)
 801                 }
 802                 ty::ReScope(_) |
 803                 ty::ReErased => Ok(()),
 804                 ty::ReStatic => write!(f, "'static"),
 805                 ty::ReEmpty => write!(f, "'<empty>"),
 806
 807                 // The user should never encounter these in unsubstituted form.
 808                 ty::ReClosureBound(vid) => write!(f, "{:?}", vid),
 809             }
 810         }
 811         debug {
 812             match *self {
 813                 ty::ReEarlyBound(ref data) => {
 814                     write!(f, "ReEarlyBound({}, {})",
 815                            data.index,
 816                            data.name)
 817                 }
 818
 819                 ty::ReClosureBound(ref vid) => {
 820                     write!(f, "ReClosureBound({:?})",
 821                            vid)
 822                 }
 823
 824                 ty::ReLateBound(binder_id, ref bound_region) => {
 825                     write!(f, "ReLateBound({:?}, {:?})",
 826                            binder_id,
 827                            bound_region)
 828                 }
 829
 830                 ty::ReFree(ref fr) => write!(f, "{:?}", fr),
 831
 832                 ty::ReScope(id) => {
 833                     write!(f, "ReScope({:?})", id)
 834                 }
 835
 836                 ty::ReStatic => write!(f, "ReStatic"),
 837
 838                 ty::ReVar(ref vid) => {
 839                     write!(f, "{:?}", vid)
 840                 }
 841
 842                 ty::RePlaceholder(placeholder) => {
 843                     write!(f, "RePlaceholder({:?})", placeholder)
 844                 }
 845
 846                 ty::ReEmpty => write!(f, "ReEmpty"),
 847
 848                 ty::ReErased => write!(f, "ReErased")
 849             }
 850         }
 851     }
 852 }
 853
 854 define_print! {
 855     () ty::FreeRegion, (self, f, cx) {
 856         debug {
 857             write!(f, "ReFree({:?}, {:?})", self.scope, self.bound_region)
 858         }
 859     }
 860 }
 861
 862 define_print! {
 863     () ty::Variance, (self, f, cx) {
 864         debug {
 865             f.write_str(match *self {
 866                 ty::Covariant => "+",
 867                 ty::Contravariant => "-",
 868                 ty::Invariant => "o",
 869                 ty::Bivariant => "*",
 870             })
 871         }
 872     }
 873 }
 874
 875 define_print! {
 876     ('tcx) ty::FnSig<'tcx>, (self, f, cx) {
 877         display {
 878             if self.unsafety == hir::Unsafety::Unsafe {
 879                 write!(f, "unsafe ")?;
 880             }
 881
 882             if self.abi != Abi::Rust {
 883                 write!(f, "extern {} ", self.abi)?;
 884             }
 885
 886             write!(f, "fn")?;
 887             cx.fn_sig(f, self.inputs(), self.c_variadic, self.output())
 888         }
 889         debug {
 890             write!(f, "({:?}; c_variadic: {})->{:?}", self.inputs(), self.c_variadic, self.output())
 891         }
 892     }
 893 }
 894
 895 impl fmt::Debug for ty::TyVid {
 896     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 897         write!(f, "_#{}t", self.index)
 898     }
 899 }
 900
 901 impl<'tcx> fmt::Debug for ty::ConstVid<'tcx> {
 902     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 903         write!(f, "_#{}f", self.index)
 904     }
 905 }
 906
 907 impl fmt::Debug for ty::IntVid {
 908     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 909         write!(f, "_#{}i", self.index)
 910     }
 911 }
 912
 913 impl fmt::Debug for ty::FloatVid {
 914     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 915         write!(f, "_#{}f", self.index)
 916     }
 917 }
 918
 919 define_print! {
 920     () ty::RegionVid, (self, f, cx) {
 921         display {
 922             if cx.is_verbose {
 923                 return self.print_debug(f, cx);
 924             }
 925
 926             let highlight = RegionHighlightMode::get();
 927             if let Some(counter) = highlight.region_highlighted(&ty::ReVar(*self)) {
 928                 return write!(f, "'{:?}", counter);
 929             }
 930
 931             Ok(())
 932         }
 933         debug {
 934             // HACK(eddyb) this is duplicated from `display` printing,
 935             // to keep NLL borrowck working even with `-Zverbose`.
 936             let highlight = RegionHighlightMode::get();
 937             if let Some(counter) = highlight.region_highlighted(&ty::ReVar(*self)) {
 938                 return write!(f, "'{:?}", counter);
 939             }
 940
 941             write!(f, "'_#{}r", self.index())
 942         }
 943     }
 944 }
 945
 946 define_print! {
 947     () ty::InferTy, (self, f, cx) {
 948         display {
 949             if cx.is_verbose {
 950                 return self.print_debug(f, cx);
 951             }
 952             match *self {
 953                 ty::TyVar(_) => write!(f, "_"),
 954                 ty::IntVar(_) => write!(f, "{}", "{integer}"),
 955                 ty::FloatVar(_) => write!(f, "{}", "{float}"),
 956                 ty::FreshTy(v) => write!(f, "FreshTy({})", v),
 957                 ty::FreshIntTy(v) => write!(f, "FreshIntTy({})", v),
 958                 ty::FreshFloatTy(v) => write!(f, "FreshFloatTy({})", v)
 959             }
 960         }
 961         debug {
 962             match *self {
 963                 ty::TyVar(ref v) => write!(f, "{:?}", v),
 964                 ty::IntVar(ref v) => write!(f, "{:?}", v),
 965                 ty::FloatVar(ref v) => write!(f, "{:?}", v),
 966                 ty::FreshTy(v) => write!(f, "FreshTy({:?})", v),
 967                 ty::FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
 968                 ty::FreshFloatTy(v) => write!(f, "FreshFloatTy({:?})", v)
 969             }
 970         }
 971     }
 972 }
 973
 974 impl fmt::Debug for ty::IntVarValue {
 975     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 976         match *self {
 977             ty::IntType(ref v) => v.fmt(f),
 978             ty::UintType(ref v) => v.fmt(f),
 979         }
 980     }
 981 }
 982
 983 impl fmt::Debug for ty::FloatVarValue {
 984     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 985         self.0.fmt(f)
 986     }
 987 }
 988
 989 // The generic impl doesn't work yet because projections are not
 990 // normalized under HRTB.
 991 /*impl<T> fmt::Display for ty::Binder<T>
 992     where T: fmt::Display + for<'a> ty::Lift<'a>,
 993           for<'a> <T as ty::Lift<'a>>::Lifted: fmt::Display + TypeFoldable<'a>
 994 {
 995     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 996         PrintCx::with(|cx| cx.in_binder(f, cx.tcx.lift(self)
 997             .expect("could not lift for printing")))
 998     }
 999 }*/
1000
1001 define_print_multi! {
1002     [
1003     ('tcx) ty::Binder<&'tcx ty::List<ty::ExistentialPredicate<'tcx>>>,
1004     ('tcx) ty::Binder<ty::TraitRef<'tcx>>,
1005     ('tcx) ty::Binder<ty::FnSig<'tcx>>,
1006     ('tcx) ty::Binder<ty::TraitPredicate<'tcx>>,
1007     ('tcx) ty::Binder<ty::SubtypePredicate<'tcx>>,
1008     ('tcx) ty::Binder<ty::ProjectionPredicate<'tcx>>,
1009     ('tcx) ty::Binder<ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>,
1010     ('tcx) ty::Binder<ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>>
1011     ]
1012     (self, f, cx) {
1013         display {
1014             cx.in_binder(f, self)
1015         }
1016     }
1017 }
1018
1019 define_print! {
1020     ('tcx) ty::TraitRef<'tcx>, (self, f, cx) {
1021         display {
1022             cx.parameterized(f, self.def_id, self.substs, iter::empty())
1023         }
1024         debug {
1025             // when printing out the debug representation, we don't need
1026             // to enumerate the `for<...>` etc because the debruijn index
1027             // tells you everything you need to know.
1028             print!(f, cx,
1029                    write("<"),
1030                    print(self.self_ty()),
1031                    write(" as "))?;
1032             cx.parameterized(f, self.def_id, self.substs, iter::empty())?;
1033             write!(f, ">")
1034         }
1035     }
1036 }
1037
1038 define_print! {
1039     ('tcx) ty::Ty<'tcx>, (self, f, cx) {
1040         display {
1041             match self.sty {
1042                 Bool => write!(f, "bool"),
1043                 Char => write!(f, "char"),
1044                 Int(t) => write!(f, "{}", t.ty_to_string()),
1045                 Uint(t) => write!(f, "{}", t.ty_to_string()),
1046                 Float(t) => write!(f, "{}", t.ty_to_string()),
1047                 RawPtr(ref tm) => {
1048                     write!(f, "*{} ", match tm.mutbl {
1049                         hir::MutMutable => "mut",
1050                         hir::MutImmutable => "const",
1051                     })?;
1052                     tm.ty.print(f, cx)
1053                 }
1054                 Ref(r, ty, mutbl) => {
1055                     write!(f, "&")?;
1056                     let s = r.print_display_to_string(cx);
1057                     if !s.is_empty() {
1058                         write!(f, "{} ", s)?;
1059                     }
1060                     ty::TypeAndMut { ty, mutbl }.print(f, cx)
1061                 }
1062                 Never => write!(f, "!"),
1063                 Tuple(ref tys) => {
1064                     write!(f, "(")?;
1065                     let mut tys = tys.iter();
1066                     if let Some(&ty) = tys.next() {
1067                         print!(f, cx, print(ty), write(","))?;
1068                         if let Some(&ty) = tys.next() {
1069                             print!(f, cx, write(" "), print(ty))?;
1070                             for &ty in tys {
1071                                 print!(f, cx, write(", "), print(ty))?;
1072                             }
1073                         }
1074                     }
1075                     write!(f, ")")
1076                 }
1077                 FnDef(def_id, substs) => {
1078                     let sig = cx.tcx.fn_sig(def_id).subst(cx.tcx, substs);
1079                     print!(f, cx, print(sig), write(" {{"))?;
1080                     cx.parameterized(f, def_id, substs, iter::empty())?;
1081                     write!(f, "}}")
1082                 }
1083                 FnPtr(ref bare_fn) => {
1084                     bare_fn.print(f, cx)
1085                 }
1086                 Infer(infer_ty) => write!(f, "{}", infer_ty),
1087                 Error => write!(f, "[type error]"),
1088                 Param(ref param_ty) => write!(f, "{}", param_ty),
1089                 Bound(debruijn, bound_ty) => {
1090                     match bound_ty.kind {
1091                         ty::BoundTyKind::Anon => {
1092                             if debruijn == ty::INNERMOST {
1093                                 write!(f, "^{}", bound_ty.var.index())
1094                             } else {
1095                                 write!(f, "^{}_{}", debruijn.index(), bound_ty.var.index())
1096                             }
1097                         }
1098
1099                         ty::BoundTyKind::Param(p) => write!(f, "{}", p),
1100                     }
1101                 }
1102                 Adt(def, substs) => cx.parameterized(f, def.did, substs, iter::empty()),
1103                 Dynamic(data, r) => {
1104                     let r = r.print_display_to_string(cx);
1105                     if !r.is_empty() {
1106                         write!(f, "(")?;
1107                     }
1108                     write!(f, "dyn ")?;
1109                     data.print(f, cx)?;
1110                     if !r.is_empty() {
1111                         write!(f, " + {})", r)
1112                     } else {
1113                         Ok(())
1114                     }
1115                 }
1116                 Foreign(def_id) => {
1117                     cx.parameterized(f, def_id, subst::InternalSubsts::empty(), iter::empty())
1118                 }
1119                 Projection(ref data) => data.print(f, cx),
1120                 UnnormalizedProjection(ref data) => {
1121                     write!(f, "Unnormalized(")?;
1122                     data.print(f, cx)?;
1123                     write!(f, ")")
1124                 }
1125                 Placeholder(placeholder) => {
1126                     write!(f, "Placeholder({:?})", placeholder)
1127                 }
1128                 Opaque(def_id, substs) => {
1129                     if cx.is_verbose {
1130                         return write!(f, "Opaque({:?}, {:?})", def_id, substs);
1131                     }
1132
1133                     let def_key = cx.tcx.def_key(def_id);
1134                     if let Some(name) = def_key.disambiguated_data.data.get_opt_name() {
1135                         write!(f, "{}", name)?;
1136                         let mut substs = substs.iter();
1137                         if let Some(first) = substs.next() {
1138                             write!(f, "::<")?;
1139                             write!(f, "{}", first)?;
1140                             for subst in substs {
1141                                 write!(f, ", {}", subst)?;
1142                             }
1143                             write!(f, ">")?;
1144                         }
1145                         return Ok(());
1146                     }
1147                     // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
1148                     // by looking up the projections associated with the def_id.
1149                     let bounds = cx.tcx.predicates_of(def_id).instantiate(cx.tcx, substs);
1150
1151                     let mut first = true;
1152                     let mut is_sized = false;
1153                     write!(f, "impl")?;
1154                     for predicate in bounds.predicates {
1155                         if let Some(trait_ref) = predicate.to_opt_poly_trait_ref() {
1156                             // Don't print +Sized, but rather +?Sized if absent.
1157                             if Some(trait_ref.def_id()) == cx.tcx.lang_items().sized_trait() {
1158                                 is_sized = true;
1159                                 continue;
1160                             }
1161
1162                             print!(f, cx,
1163                                     write("{}", if first { " " } else { "+" }),
1164                                     print(trait_ref))?;
1165                             first = false;
1166                         }
1167                     }
1168                     if !is_sized {
1169                         write!(f, "{}?Sized", if first { " " } else { "+" })?;
1170                         } else if first {
1171                             write!(f, " Sized")?;
1172                     }
1173                     Ok(())
1174                 }
1175                 Str => write!(f, "str"),
1176                 Generator(did, substs, movability) => {
1177                     let upvar_tys = substs.upvar_tys(did, cx.tcx);
1178                     let witness = substs.witness(did, cx.tcx);
1179                     if movability == hir::GeneratorMovability::Movable {
1180                         write!(f, "[generator")?;
1181                     } else {
1182                         write!(f, "[static generator")?;
1183                     }
1184
1185                     if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(did) {
1186                         write!(f, "@{:?}", cx.tcx.hir().span_by_hir_id(hir_id))?;
1187                         let mut sep = " ";
1188                         cx.tcx.with_freevars(hir_id, |freevars| {
1189                             for (freevar, upvar_ty) in freevars.iter().zip(upvar_tys) {
1190                                 print!(f, cx,
1191                                        write("{}{}:",
1192                                              sep,
1193                                              cx.tcx.hir().name(freevar.var_id())),
1194                                        print(upvar_ty))?;
1195                                 sep = ", ";
1196                             }
1197                             Ok(())
1198                         })?
1199                     } else {
1200                         // cross-crate closure types should only be
1201                         // visible in codegen bug reports, I imagine.
1202                         write!(f, "@{:?}", did)?;
1203                         let mut sep = " ";
1204                         for (index, upvar_ty) in upvar_tys.enumerate() {
1205                             print!(f, cx,
1206                                    write("{}{}:", sep, index),
1207                                    print(upvar_ty))?;
1208                             sep = ", ";
1209                         }
1210                     }
1211
1212                     print!(f, cx, write(" "), print(witness), write("]"))
1213                 },
1214                 GeneratorWitness(types) => {
1215                     cx.in_binder(f, &types)
1216                 }
1217                 Closure(did, substs) => {
1218                     let upvar_tys = substs.upvar_tys(did, cx.tcx);
1219                     write!(f, "[closure")?;
1220
1221                     if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(did) {
1222                         if cx.tcx.sess.opts.debugging_opts.span_free_formats {
1223                             write!(f, "@{:?}", hir_id)?;
1224                         } else {
1225                             write!(f, "@{:?}", cx.tcx.hir().span_by_hir_id(hir_id))?;
1226                         }
1227                         let mut sep = " ";
1228                         cx.tcx.with_freevars(hir_id, |freevars| {
1229                             for (freevar, upvar_ty) in freevars.iter().zip(upvar_tys) {
1230                                 print!(f, cx,
1231                                        write("{}{}:",
1232                                              sep,
1233                                              cx.tcx.hir().name(freevar.var_id())),
1234                                        print(upvar_ty))?;
1235                                 sep = ", ";
1236                             }
1237                             Ok(())
1238                         })?
1239                     } else {
1240                         // cross-crate closure types should only be
1241                         // visible in codegen bug reports, I imagine.
1242                         write!(f, "@{:?}", did)?;
1243                         let mut sep = " ";
1244                         for (index, upvar_ty) in upvar_tys.enumerate() {
1245                             print!(f, cx,
1246                                    write("{}{}:", sep, index),
1247                                    print(upvar_ty))?;
1248                             sep = ", ";
1249                         }
1250                     }
1251
1252                     if cx.is_verbose {
1253                         write!(
1254                             f,
1255                             " closure_kind_ty={:?} closure_sig_ty={:?}",
1256                             substs.closure_kind_ty(did, cx.tcx),
1257                             substs.closure_sig_ty(did, cx.tcx),
1258                         )?;
1259                     }
1260
1261                     write!(f, "]")
1262                 },
1263                 Array(ty, sz) => {
1264                     print!(f, cx, write("["), print(ty), write("; "))?;
1265                     match sz {
1266                         ty::LazyConst::Unevaluated(_def_id, _substs) => {
1267                             write!(f, "_")?;
1268                         }
1269                         ty::LazyConst::Evaluated(c) => {
1270                             match c.val {
1271                                 ConstValue::Infer(..) => write!(f, "_")?,
1272                                 ConstValue::Param(ParamConst { name, .. }) =>
1273                                     write!(f, "{}", name)?,
1274                                 _ => write!(f, "{}", c.unwrap_usize(cx.tcx))?,
1275                             }
1276                         }
1277                     }
1278                     write!(f, "]")
1279                 }
1280                 Slice(ty) => {
1281                     print!(f, cx, write("["), print(ty), write("]"))
1282                 }
1283             }
1284         }
1285         debug {
1286             self.print_display(f, cx)
1287         }
1288     }
1289 }
1290
1291 define_print! {
1292     ('tcx) ConstValue<'tcx>, (self, f, cx) {
1293         display {
1294             match self {
1295                 ConstValue::Infer(..) => write!(f, "_"),
1296                 ConstValue::Param(ParamConst { name, .. }) => write!(f, "{}", name),
1297                 _ => write!(f, "{:?}", self),
1298             }
1299         }
1300     }
1301 }
1302
1303 define_print! {
1304     ('tcx) ty::Const<'tcx>, (self, f, cx) {
1305         display {
1306             write!(f, "{} : {}", self.val, self.ty)
1307         }
1308     }
1309 }
1310
1311 define_print! {
1312     ('tcx) ty::LazyConst<'tcx>, (self, f, cx) {
1313         display {
1314             match self {
1315                 ty::LazyConst::Unevaluated(..) => write!(f, "_ : _"),
1316                 ty::LazyConst::Evaluated(c) => write!(f, "{}", c),
1317             }
1318         }
1319     }
1320 }
1321
1322 define_print! {
1323     () ty::ParamTy, (self, f, cx) {
1324         display {
1325             write!(f, "{}", self.name)
1326         }
1327         debug {
1328             write!(f, "{}/#{}", self.name, self.idx)
1329         }
1330     }
1331 }
1332
1333 define_print! {
1334     () ty::ParamConst, (self, f, cx) {
1335         display {
1336             write!(f, "{}", self.name)
1337         }
1338         debug {
1339             write!(f, "{}/#{}", self.name, self.index)
1340         }
1341     }
1342 }
1343
1344 // Similar problem to `Binder<T>`, can't define a generic impl.
1345 define_print_multi! {
1346     [
1347     ('tcx) ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
1348     ('tcx) ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
1349     ]
1350     (self, f, cx) {
1351         display {
1352             print!(f, cx, print(self.0), write(" : "), print(self.1))
1353         }
1354     }
1355 }
1356
1357 define_print! {
1358     ('tcx) ty::SubtypePredicate<'tcx>, (self, f, cx) {
1359         display {
1360             print!(f, cx, print(self.a), write(" <: "), print(self.b))
1361         }
1362     }
1363 }
1364
1365 define_print! {
1366     ('tcx) ty::TraitPredicate<'tcx>, (self, f, cx) {
1367         debug {
1368             write!(f, "TraitPredicate({:?})",
1369                    self.trait_ref)
1370         }
1371         display {
1372             print!(f, cx, print(self.trait_ref.self_ty()), write(": "), print(self.trait_ref))
1373         }
1374     }
1375 }
1376
1377 define_print! {
1378     ('tcx) ty::ProjectionPredicate<'tcx>, (self, f, cx) {
1379         debug {
1380             print!(f, cx,
1381                    write("ProjectionPredicate("),
1382                    print(self.projection_ty),
1383                    write(", "),
1384                    print(self.ty),
1385                    write(")"))
1386         }
1387         display {
1388             print!(f, cx, print(self.projection_ty), write(" == "), print(self.ty))
1389         }
1390     }
1391 }
1392
1393 define_print! {
1394     ('tcx) ty::ProjectionTy<'tcx>, (self, f, cx) {
1395         display {
1396             cx.parameterized(f, self.item_def_id, self.substs, iter::empty())
1397         }
1398     }
1399 }
1400
1401 define_print! {
1402     () ty::ClosureKind, (self, f, cx) {
1403         display {
1404             match *self {
1405                 ty::ClosureKind::Fn => write!(f, "Fn"),
1406                 ty::ClosureKind::FnMut => write!(f, "FnMut"),
1407                 ty::ClosureKind::FnOnce => write!(f, "FnOnce"),
1408             }
1409         }
1410     }
1411 }
1412
1413 define_print! {
1414     ('tcx) ty::Predicate<'tcx>, (self, f, cx) {
1415         display {
1416             match *self {
1417                 ty::Predicate::Trait(ref data) => data.print(f, cx),
1418                 ty::Predicate::Subtype(ref predicate) => predicate.print(f, cx),
1419                 ty::Predicate::RegionOutlives(ref predicate) => predicate.print(f, cx),
1420                 ty::Predicate::TypeOutlives(ref predicate) => predicate.print(f, cx),
1421                 ty::Predicate::Projection(ref predicate) => predicate.print(f, cx),
1422                 ty::Predicate::WellFormed(ty) => print!(f, cx, print(ty), write(" well-formed")),
1423                 ty::Predicate::ObjectSafe(trait_def_id) => {
1424                     write!(f, "the trait `{}` is object-safe", cx.tcx.item_path_str(trait_def_id))
1425                 }
1426                 ty::Predicate::ClosureKind(closure_def_id, _closure_substs, kind) => {
1427                     write!(f, "the closure `{}` implements the trait `{}`",
1428                            cx.tcx.item_path_str(closure_def_id), kind)
1429                 }
1430                 ty::Predicate::ConstEvaluatable(def_id, substs) => {
1431                     write!(f, "the constant `")?;
1432                     cx.parameterized(f, def_id, substs, iter::empty())?;
1433                     write!(f, "` can be evaluated")
1434                 }
1435             }
1436         }
1437         debug {
1438             match *self {
1439                 ty::Predicate::Trait(ref a) => a.print(f, cx),
1440                 ty::Predicate::Subtype(ref pair) => pair.print(f, cx),
1441                 ty::Predicate::RegionOutlives(ref pair) => pair.print(f, cx),
1442                 ty::Predicate::TypeOutlives(ref pair) => pair.print(f, cx),
1443                 ty::Predicate::Projection(ref pair) => pair.print(f, cx),
1444                 ty::Predicate::WellFormed(ty) => ty.print(f, cx),
1445                 ty::Predicate::ObjectSafe(trait_def_id) => {
1446                     write!(f, "ObjectSafe({:?})", trait_def_id)
1447                 }
1448                 ty::Predicate::ClosureKind(closure_def_id, closure_substs, kind) => {
1449                     write!(f, "ClosureKind({:?}, {:?}, {:?})", closure_def_id, closure_substs, kind)
1450                 }
1451                 ty::Predicate::ConstEvaluatable(def_id, substs) => {
1452                     write!(f, "ConstEvaluatable({:?}, {:?})", def_id, substs)
1453                 }
1454             }
1455         }
1456     }
1457 }
1458
1459 define_print! {
1460     ('tcx) Kind<'tcx>, (self, f, cx) {
1461         display {
1462             match self.unpack() {
1463                 UnpackedKind::Lifetime(lt) => print!(f, cx, print(lt)),
1464                 UnpackedKind::Type(ty) => print!(f, cx, print(ty)),
1465                 UnpackedKind::Const(ct) => print!(f, cx, print(ct)),
1466             }
1467         }
1468         debug {
1469             match self.unpack() {
1470                 UnpackedKind::Lifetime(lt) => print!(f, cx, print(lt)),
1471                 UnpackedKind::Type(ty) => print!(f, cx, print(ty)),
1472                 UnpackedKind::Const(ct) => print!(f, cx, print(ct)),
1473             }
1474         }
1475     }
1476 }