compiler/rustc_middle/src/traits/chalk.rs

   1 //! Types required for Chalk-related queries
   2 //!
   3 //! The primary purpose of this file is defining an implementation for the
   4 //! `chalk_ir::interner::Interner` trait. The primary purpose of this trait, as
   5 //! its name suggest, is to provide an abstraction boundary for creating
   6 //! interned Chalk types.
   7
   8 use rustc_middle::ty::{self, AdtDef, TyCtxt};
   9
  10 use rustc_hir::def_id::DefId;
  11 use rustc_target::spec::abi::Abi;
  12
  13 use std::cmp::Ordering;
  14 use std::fmt;
  15 use std::hash::{Hash, Hasher};
  16
  17 #[derive(Copy, Clone)]
  18 pub struct RustInterner<'tcx> {
  19     pub tcx: TyCtxt<'tcx>,
  20 }
  21
  22 /// We don't ever actually need this. It's only required for derives.
  23 impl<'tcx> Hash for RustInterner<'tcx> {
  24     fn hash<H: Hasher>(&self, _state: &mut H) {}
  25 }
  26
  27 /// We don't ever actually need this. It's only required for derives.
  28 impl<'tcx> Ord for RustInterner<'tcx> {
  29     fn cmp(&self, _other: &Self) -> Ordering {
  30         Ordering::Equal
  31     }
  32 }
  33
  34 /// We don't ever actually need this. It's only required for derives.
  35 impl<'tcx> PartialOrd for RustInterner<'tcx> {
  36     fn partial_cmp(&self, _other: &Self) -> Option<Ordering> {
  37         None
  38     }
  39 }
  40
  41 /// We don't ever actually need this. It's only required for derives.
  42 impl<'tcx> PartialEq for RustInterner<'tcx> {
  43     fn eq(&self, _other: &Self) -> bool {
  44         false
  45     }
  46 }
  47
  48 /// We don't ever actually need this. It's only required for derives.
  49 impl<'tcx> Eq for RustInterner<'tcx> {}
  50
  51 impl fmt::Debug for RustInterner<'_> {
  52     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  53         write!(f, "RustInterner")
  54     }
  55 }
  56
  57 // Right now, there is no interning at all. I was running into problems with
  58 // adding interning in `ty/context.rs` for Chalk types with
  59 // `parallel-compiler = true`. -jackh726
  60 impl<'tcx> chalk_ir::interner::Interner for RustInterner<'tcx> {
  61     type InternedType = Box<chalk_ir::TyData<Self>>;
  62     type InternedLifetime = Box<chalk_ir::LifetimeData<Self>>;
  63     type InternedConst = Box<chalk_ir::ConstData<Self>>;
  64     type InternedConcreteConst = ty::ValTree<'tcx>;
  65     type InternedGenericArg = Box<chalk_ir::GenericArgData<Self>>;
  66     type InternedGoal = Box<chalk_ir::GoalData<Self>>;
  67     type InternedGoals = Vec<chalk_ir::Goal<Self>>;
  68     type InternedSubstitution = Vec<chalk_ir::GenericArg<Self>>;
  69     type InternedProgramClause = Box<chalk_ir::ProgramClauseData<Self>>;
  70     type InternedProgramClauses = Vec<chalk_ir::ProgramClause<Self>>;
  71     type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
  72     type InternedVariableKinds = Vec<chalk_ir::VariableKind<Self>>;
  73     type InternedCanonicalVarKinds = Vec<chalk_ir::CanonicalVarKind<Self>>;
  74     type InternedVariances = Vec<chalk_ir::Variance>;
  75     type InternedConstraints = Vec<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>>;
  76     type DefId = DefId;
  77     type InternedAdtId = AdtDef<'tcx>;
  78     type Identifier = ();
  79     type FnAbi = Abi;
  80
  81     fn debug_program_clause_implication(
  82         pci: &chalk_ir::ProgramClauseImplication<Self>,
  83         fmt: &mut fmt::Formatter<'_>,
  84     ) -> Option<fmt::Result> {
  85         let mut write = || {
  86             write!(fmt, "{:?}", pci.consequence)?;
  87
  88             let conditions = pci.conditions.interned();
  89             let constraints = pci.constraints.interned();
  90
  91             let conds = conditions.len();
  92             let consts = constraints.len();
  93             if conds == 0 && consts == 0 {
  94                 return Ok(());
  95             }
  96
  97             write!(fmt, " :- ")?;
  98
  99             if conds != 0 {
 100                 for cond in &conditions[..conds - 1] {
 101                     write!(fmt, "{:?}, ", cond)?;
 102                 }
 103                 write!(fmt, "{:?}", conditions[conds - 1])?;
 104             }
 105
 106             if conds != 0 && consts != 0 {
 107                 write!(fmt, " ; ")?;
 108             }
 109
 110             if consts != 0 {
 111                 for constraint in &constraints[..consts - 1] {
 112                     write!(fmt, "{:?}, ", constraint)?;
 113                 }
 114                 write!(fmt, "{:?}", constraints[consts - 1])?;
 115             }
 116
 117             Ok(())
 118         };
 119         Some(write())
 120     }
 121
 122     fn debug_substitution(
 123         substitution: &chalk_ir::Substitution<Self>,
 124         fmt: &mut fmt::Formatter<'_>,
 125     ) -> Option<fmt::Result> {
 126         Some(write!(fmt, "{:?}", substitution.interned()))
 127     }
 128
 129     fn debug_separator_trait_ref(
 130         separator_trait_ref: &chalk_ir::SeparatorTraitRef<'_, Self>,
 131         fmt: &mut fmt::Formatter<'_>,
 132     ) -> Option<fmt::Result> {
 133         let substitution = &separator_trait_ref.trait_ref.substitution;
 134         let parameters = substitution.interned();
 135         Some(write!(
 136             fmt,
 137             "{:?}{}{:?}{:?}",
 138             parameters[0],
 139             separator_trait_ref.separator,
 140             separator_trait_ref.trait_ref.trait_id,
 141             chalk_ir::debug::Angle(&parameters[1..])
 142         ))
 143     }
 144
 145     fn debug_quantified_where_clauses(
 146         clauses: &chalk_ir::QuantifiedWhereClauses<Self>,
 147         fmt: &mut fmt::Formatter<'_>,
 148     ) -> Option<fmt::Result> {
 149         Some(write!(fmt, "{:?}", clauses.interned()))
 150     }
 151
 152     fn debug_ty(ty: &chalk_ir::Ty<Self>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
 153         match &ty.interned().kind {
 154             chalk_ir::TyKind::Ref(chalk_ir::Mutability::Not, lifetime, ty) => {
 155                 Some(write!(fmt, "(&{:?} {:?})", lifetime, ty))
 156             }
 157             chalk_ir::TyKind::Ref(chalk_ir::Mutability::Mut, lifetime, ty) => {
 158                 Some(write!(fmt, "(&{:?} mut {:?})", lifetime, ty))
 159             }
 160             chalk_ir::TyKind::Array(ty, len) => Some(write!(fmt, "[{:?}; {:?}]", ty, len)),
 161             chalk_ir::TyKind::Slice(ty) => Some(write!(fmt, "[{:?}]", ty)),
 162             chalk_ir::TyKind::Tuple(len, substs) => Some((|| {
 163                 write!(fmt, "(")?;
 164                 for (idx, substitution) in substs.interned().iter().enumerate() {
 165                     if idx == *len && *len != 1 {
 166                         // Don't add a trailing comma if the tuple has more than one element
 167                         write!(fmt, "{:?}", substitution)?;
 168                     } else {
 169                         write!(fmt, "{:?},", substitution)?;
 170                     }
 171                 }
 172                 write!(fmt, ")")
 173             })()),
 174             _ => None,
 175         }
 176     }
 177
 178     fn debug_alias(
 179         alias_ty: &chalk_ir::AliasTy<Self>,
 180         fmt: &mut fmt::Formatter<'_>,
 181     ) -> Option<fmt::Result> {
 182         match alias_ty {
 183             chalk_ir::AliasTy::Projection(projection_ty) => {
 184                 Self::debug_projection_ty(projection_ty, fmt)
 185             }
 186             chalk_ir::AliasTy::Opaque(opaque_ty) => Self::debug_opaque_ty(opaque_ty, fmt),
 187         }
 188     }
 189
 190     fn debug_projection_ty(
 191         projection_ty: &chalk_ir::ProjectionTy<Self>,
 192         fmt: &mut fmt::Formatter<'_>,
 193     ) -> Option<fmt::Result> {
 194         Some(write!(
 195             fmt,
 196             "projection: {:?} {:?}",
 197             projection_ty.associated_ty_id, projection_ty.substitution,
 198         ))
 199     }
 200
 201     fn debug_opaque_ty(
 202         opaque_ty: &chalk_ir::OpaqueTy<Self>,
 203         fmt: &mut fmt::Formatter<'_>,
 204     ) -> Option<fmt::Result> {
 205         Some(write!(fmt, "{:?}", opaque_ty.opaque_ty_id))
 206     }
 207
 208     fn intern_ty(self, ty: chalk_ir::TyKind<Self>) -> Self::InternedType {
 209         let flags = ty.compute_flags(self);
 210         Box::new(chalk_ir::TyData { kind: ty, flags: flags })
 211     }
 212
 213     fn ty_data<'a>(self, ty: &'a Self::InternedType) -> &'a chalk_ir::TyData<Self> {
 214         ty
 215     }
 216
 217     fn intern_lifetime(self, lifetime: chalk_ir::LifetimeData<Self>) -> Self::InternedLifetime {
 218         Box::new(lifetime)
 219     }
 220
 221     fn lifetime_data<'a>(
 222         self,
 223         lifetime: &'a Self::InternedLifetime,
 224     ) -> &'a chalk_ir::LifetimeData<Self> {
 225         &lifetime
 226     }
 227
 228     fn intern_const(self, constant: chalk_ir::ConstData<Self>) -> Self::InternedConst {
 229         Box::new(constant)
 230     }
 231
 232     fn const_data<'a>(self, constant: &'a Self::InternedConst) -> &'a chalk_ir::ConstData<Self> {
 233         &constant
 234     }
 235
 236     fn const_eq(
 237         self,
 238         _ty: &Self::InternedType,
 239         c1: &Self::InternedConcreteConst,
 240         c2: &Self::InternedConcreteConst,
 241     ) -> bool {
 242         c1 == c2
 243     }
 244
 245     fn intern_generic_arg(self, data: chalk_ir::GenericArgData<Self>) -> Self::InternedGenericArg {
 246         Box::new(data)
 247     }
 248
 249     fn generic_arg_data<'a>(
 250         self,
 251         data: &'a Self::InternedGenericArg,
 252     ) -> &'a chalk_ir::GenericArgData<Self> {
 253         &data
 254     }
 255
 256     fn intern_goal(self, goal: chalk_ir::GoalData<Self>) -> Self::InternedGoal {
 257         Box::new(goal)
 258     }
 259
 260     fn goal_data<'a>(self, goal: &'a Self::InternedGoal) -> &'a chalk_ir::GoalData<Self> {
 261         &goal
 262     }
 263
 264     fn intern_goals<E>(
 265         self,
 266         data: impl IntoIterator<Item = Result<chalk_ir::Goal<Self>, E>>,
 267     ) -> Result<Self::InternedGoals, E> {
 268         data.into_iter().collect::<Result<Vec<_>, _>>()
 269     }
 270
 271     fn goals_data<'a>(self, goals: &'a Self::InternedGoals) -> &'a [chalk_ir::Goal<Self>] {
 272         goals
 273     }
 274
 275     fn intern_substitution<E>(
 276         self,
 277         data: impl IntoIterator<Item = Result<chalk_ir::GenericArg<Self>, E>>,
 278     ) -> Result<Self::InternedSubstitution, E> {
 279         data.into_iter().collect::<Result<Vec<_>, _>>()
 280     }
 281
 282     fn substitution_data<'a>(
 283         self,
 284         substitution: &'a Self::InternedSubstitution,
 285     ) -> &'a [chalk_ir::GenericArg<Self>] {
 286         substitution
 287     }
 288
 289     fn intern_program_clause(
 290         self,
 291         data: chalk_ir::ProgramClauseData<Self>,
 292     ) -> Self::InternedProgramClause {
 293         Box::new(data)
 294     }
 295
 296     fn program_clause_data<'a>(
 297         self,
 298         clause: &'a Self::InternedProgramClause,
 299     ) -> &'a chalk_ir::ProgramClauseData<Self> {
 300         &clause
 301     }
 302
 303     fn intern_program_clauses<E>(
 304         self,
 305         data: impl IntoIterator<Item = Result<chalk_ir::ProgramClause<Self>, E>>,
 306     ) -> Result<Self::InternedProgramClauses, E> {
 307         data.into_iter().collect::<Result<Vec<_>, _>>()
 308     }
 309
 310     fn program_clauses_data<'a>(
 311         self,
 312         clauses: &'a Self::InternedProgramClauses,
 313     ) -> &'a [chalk_ir::ProgramClause<Self>] {
 314         clauses
 315     }
 316
 317     fn intern_quantified_where_clauses<E>(
 318         self,
 319         data: impl IntoIterator<Item = Result<chalk_ir::QuantifiedWhereClause<Self>, E>>,
 320     ) -> Result<Self::InternedQuantifiedWhereClauses, E> {
 321         data.into_iter().collect::<Result<Vec<_>, _>>()
 322     }
 323
 324     fn quantified_where_clauses_data<'a>(
 325         self,
 326         clauses: &'a Self::InternedQuantifiedWhereClauses,
 327     ) -> &'a [chalk_ir::QuantifiedWhereClause<Self>] {
 328         clauses
 329     }
 330
 331     fn intern_generic_arg_kinds<E>(
 332         self,
 333         data: impl IntoIterator<Item = Result<chalk_ir::VariableKind<Self>, E>>,
 334     ) -> Result<Self::InternedVariableKinds, E> {
 335         data.into_iter().collect::<Result<Vec<_>, _>>()
 336     }
 337
 338     fn variable_kinds_data<'a>(
 339         self,
 340         parameter_kinds: &'a Self::InternedVariableKinds,
 341     ) -> &'a [chalk_ir::VariableKind<Self>] {
 342         parameter_kinds
 343     }
 344
 345     fn intern_canonical_var_kinds<E>(
 346         self,
 347         data: impl IntoIterator<Item = Result<chalk_ir::CanonicalVarKind<Self>, E>>,
 348     ) -> Result<Self::InternedCanonicalVarKinds, E> {
 349         data.into_iter().collect::<Result<Vec<_>, _>>()
 350     }
 351
 352     fn canonical_var_kinds_data<'a>(
 353         self,
 354         canonical_var_kinds: &'a Self::InternedCanonicalVarKinds,
 355     ) -> &'a [chalk_ir::CanonicalVarKind<Self>] {
 356         canonical_var_kinds
 357     }
 358
 359     fn intern_constraints<E>(
 360         self,
 361         data: impl IntoIterator<Item = Result<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>, E>>,
 362     ) -> Result<Self::InternedConstraints, E> {
 363         data.into_iter().collect::<Result<Vec<_>, _>>()
 364     }
 365
 366     fn constraints_data<'a>(
 367         self,
 368         constraints: &'a Self::InternedConstraints,
 369     ) -> &'a [chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>] {
 370         constraints
 371     }
 372
 373     fn intern_variances<E>(
 374         self,
 375         data: impl IntoIterator<Item = Result<chalk_ir::Variance, E>>,
 376     ) -> Result<Self::InternedVariances, E> {
 377         data.into_iter().collect::<Result<Vec<_>, _>>()
 378     }
 379
 380     fn variances_data<'a>(
 381         self,
 382         variances: &'a Self::InternedVariances,
 383     ) -> &'a [chalk_ir::Variance] {
 384         variances
 385     }
 386 }
 387
 388 impl<'tcx> chalk_ir::interner::HasInterner for RustInterner<'tcx> {
 389     type Interner = Self;
 390 }
 391
 392 /// A chalk environment and goal.
 393 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, HashStable, TypeFoldable, TypeVisitable)]
 394 pub struct ChalkEnvironmentAndGoal<'tcx> {
 395     pub environment: &'tcx ty::List<ty::Predicate<'tcx>>,
 396     pub goal: ty::Predicate<'tcx>,
 397 }
 398
 399 impl<'tcx> fmt::Display for ChalkEnvironmentAndGoal<'tcx> {
 400     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 401         write!(f, "environment: {:?}, goal: {}", self.environment, self.goal)
 402     }
 403 }