src/librustc/ty/print/obsolete.rs

   1 //! Allows for producing a unique string key for a mono item.
   2 //! These keys are used by the handwritten auto-tests, so they need to be
   3 //! predictable and human-readable.
   4 //!
   5 //! Note: A lot of this could looks very similar to what's already in `ty::print`.
   6 //! FIXME(eddyb) implement a custom `PrettyPrinter` for this.
   7
   8 use rustc::hir::def_id::DefId;
   9 use rustc::mir::interpret::ConstValue;
  10 use rustc::ty::subst::SubstsRef;
  11 use rustc::ty::{self, ClosureSubsts, Const, GeneratorSubsts, Instance, Ty, TyCtxt};
  12 use rustc::{bug, hir};
  13 use std::fmt::Write;
  14 use std::iter;
  15 use syntax::ast;
  16
  17 /// Same as `unique_type_name()` but with the result pushed onto the given
  18 /// `output` parameter.
  19 pub struct DefPathBasedNames<'tcx> {
  20     tcx: TyCtxt<'tcx>,
  21     omit_disambiguators: bool,
  22     omit_local_crate_name: bool,
  23 }
  24
  25 impl DefPathBasedNames<'tcx> {
  26     pub fn new(tcx: TyCtxt<'tcx>, omit_disambiguators: bool, omit_local_crate_name: bool) -> Self {
  27         DefPathBasedNames { tcx, omit_disambiguators, omit_local_crate_name }
  28     }
  29
  30     // Pushes the type name of the specified type to the provided string.
  31     // If `debug` is true, printing normally unprintable types is allowed
  32     // (e.g. `ty::GeneratorWitness`). This parameter should only be set when
  33     // this method is being used for logging purposes (e.g. with `debug!` or `info!`)
  34     // When being used for codegen purposes, `debug` should be set to `false`
  35     // in order to catch unexpected types that should never end up in a type name.
  36     pub fn push_type_name(&self, t: Ty<'tcx>, output: &mut String, debug: bool) {
  37         match t.sty {
  38             ty::Bool => output.push_str("bool"),
  39             ty::Char => output.push_str("char"),
  40             ty::Str => output.push_str("str"),
  41             ty::Never => output.push_str("!"),
  42             ty::Int(ast::IntTy::Isize) => output.push_str("isize"),
  43             ty::Int(ast::IntTy::I8) => output.push_str("i8"),
  44             ty::Int(ast::IntTy::I16) => output.push_str("i16"),
  45             ty::Int(ast::IntTy::I32) => output.push_str("i32"),
  46             ty::Int(ast::IntTy::I64) => output.push_str("i64"),
  47             ty::Int(ast::IntTy::I128) => output.push_str("i128"),
  48             ty::Uint(ast::UintTy::Usize) => output.push_str("usize"),
  49             ty::Uint(ast::UintTy::U8) => output.push_str("u8"),
  50             ty::Uint(ast::UintTy::U16) => output.push_str("u16"),
  51             ty::Uint(ast::UintTy::U32) => output.push_str("u32"),
  52             ty::Uint(ast::UintTy::U64) => output.push_str("u64"),
  53             ty::Uint(ast::UintTy::U128) => output.push_str("u128"),
  54             ty::Float(ast::FloatTy::F32) => output.push_str("f32"),
  55             ty::Float(ast::FloatTy::F64) => output.push_str("f64"),
  56             ty::Adt(adt_def, substs) => {
  57                 self.push_def_path(adt_def.did, output);
  58                 self.push_generic_params(substs, iter::empty(), output, debug);
  59             }
  60             ty::Tuple(component_types) => {
  61                 output.push('(');
  62                 for &component_type in component_types {
  63                     self.push_type_name(component_type.expect_ty(), output, debug);
  64                     output.push_str(", ");
  65                 }
  66                 if !component_types.is_empty() {
  67                     output.pop();
  68                     output.pop();
  69                 }
  70                 output.push(')');
  71             }
  72             ty::RawPtr(ty::TypeAndMut { ty: inner_type, mutbl }) => {
  73                 output.push('*');
  74                 match mutbl {
  75                     hir::MutImmutable => output.push_str("const "),
  76                     hir::MutMutable => output.push_str("mut "),
  77                 }
  78
  79                 self.push_type_name(inner_type, output, debug);
  80             }
  81             ty::Ref(_, inner_type, mutbl) => {
  82                 output.push('&');
  83                 if mutbl == hir::MutMutable {
  84                     output.push_str("mut ");
  85                 }
  86
  87                 self.push_type_name(inner_type, output, debug);
  88             }
  89             ty::Array(inner_type, len) => {
  90                 output.push('[');
  91                 self.push_type_name(inner_type, output, debug);
  92                 let len = len.eval_usize(self.tcx, ty::ParamEnv::reveal_all());
  93                 write!(output, "; {}", len).unwrap();
  94                 output.push(']');
  95             }
  96             ty::Slice(inner_type) => {
  97                 output.push('[');
  98                 self.push_type_name(inner_type, output, debug);
  99                 output.push(']');
 100             }
 101             ty::Dynamic(ref trait_data, ..) => {
 102                 if let Some(principal) = trait_data.principal() {
 103                     self.push_def_path(principal.def_id(), output);
 104                     self.push_generic_params(
 105                         principal.skip_binder().substs,
 106                         trait_data.projection_bounds(),
 107                         output,
 108                         debug,
 109                     );
 110                 } else {
 111                     output.push_str("dyn '_");
 112                 }
 113             }
 114             ty::Foreign(did) => self.push_def_path(did, output),
 115             ty::FnDef(..) | ty::FnPtr(_) => {
 116                 let sig = t.fn_sig(self.tcx);
 117                 if sig.unsafety() == hir::Unsafety::Unsafe {
 118                     output.push_str("unsafe ");
 119                 }
 120
 121                 let abi = sig.abi();
 122                 if abi != ::rustc_target::spec::abi::Abi::Rust {
 123                     output.push_str("extern \"");
 124                     output.push_str(abi.name());
 125                     output.push_str("\" ");
 126                 }
 127
 128                 output.push_str("fn(");
 129
 130                 let sig =
 131                     self.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
 132
 133                 if !sig.inputs().is_empty() {
 134                     for &parameter_type in sig.inputs() {
 135                         self.push_type_name(parameter_type, output, debug);
 136                         output.push_str(", ");
 137                     }
 138                     output.pop();
 139                     output.pop();
 140                 }
 141
 142                 if sig.c_variadic {
 143                     if !sig.inputs().is_empty() {
 144                         output.push_str(", ...");
 145                     } else {
 146                         output.push_str("...");
 147                     }
 148                 }
 149
 150                 output.push(')');
 151
 152                 if !sig.output().is_unit() {
 153                     output.push_str(" -> ");
 154                     self.push_type_name(sig.output(), output, debug);
 155                 }
 156             }
 157             ty::Generator(def_id, GeneratorSubsts { ref substs }, _)
 158             | ty::Closure(def_id, ClosureSubsts { ref substs }) => {
 159                 self.push_def_path(def_id, output);
 160                 let generics = self.tcx.generics_of(self.tcx.closure_base_def_id(def_id));
 161                 let substs = substs.truncate_to(self.tcx, generics);
 162                 self.push_generic_params(substs, iter::empty(), output, debug);
 163             }
 164             ty::Error
 165             | ty::Bound(..)
 166             | ty::Infer(_)
 167             | ty::Placeholder(..)
 168             | ty::UnnormalizedProjection(..)
 169             | ty::Projection(..)
 170             | ty::Param(_)
 171             | ty::GeneratorWitness(_)
 172             | ty::Opaque(..) => {
 173                 if debug {
 174                     output.push_str(&format!("`{:?}`", t));
 175                 } else {
 176                     bug!(
 177                         "DefPathBasedNames: trying to create type name for unexpected type: {:?}",
 178                         t,
 179                     );
 180                 }
 181             }
 182         }
 183     }
 184
 185     // Pushes the the name of the specified const to the provided string.
 186     // If `debug` is true, usually-unprintable consts (such as `Infer`) will be printed,
 187     // as well as the unprintable types of constants (see `push_type_name` for more details).
 188     pub fn push_const_name(&self, c: &Const<'tcx>, output: &mut String, debug: bool) {
 189         match c.val {
 190             ConstValue::Scalar(..) | ConstValue::Slice { .. } | ConstValue::ByRef { .. } => {
 191                 // FIXME(const_generics): we could probably do a better job here.
 192                 write!(output, "{:?}", c).unwrap()
 193             }
 194             _ => {
 195                 if debug {
 196                     write!(output, "{:?}", c).unwrap()
 197                 } else {
 198                     bug!(
 199                         "DefPathBasedNames: trying to create const name for unexpected const: {:?}",
 200                         c,
 201                     );
 202                 }
 203             }
 204         }
 205         output.push_str(": ");
 206         self.push_type_name(c.ty, output, debug);
 207     }
 208
 209     pub fn push_def_path(&self, def_id: DefId, output: &mut String) {
 210         let def_path = self.tcx.def_path(def_id);
 211
 212         // some_crate::
 213         if !(self.omit_local_crate_name && def_id.is_local()) {
 214             output.push_str(&self.tcx.crate_name(def_path.krate).as_str());
 215             output.push_str("::");
 216         }
 217
 218         // foo::bar::ItemName::
 219         for part in self.tcx.def_path(def_id).data {
 220             if self.omit_disambiguators {
 221                 write!(output, "{}::", part.data.as_interned_str()).unwrap();
 222             } else {
 223                 write!(output, "{}[{}]::", part.data.as_interned_str(), part.disambiguator)
 224                     .unwrap();
 225             }
 226         }
 227
 228         // remove final "::"
 229         output.pop();
 230         output.pop();
 231     }
 232
 233     fn push_generic_params<I>(
 234         &self,
 235         substs: SubstsRef<'tcx>,
 236         projections: I,
 237         output: &mut String,
 238         debug: bool,
 239     ) where
 240         I: Iterator<Item = ty::PolyExistentialProjection<'tcx>>,
 241     {
 242         let mut projections = projections.peekable();
 243         if substs.non_erasable_generics().next().is_none() && projections.peek().is_none() {
 244             return;
 245         }
 246
 247         output.push('<');
 248
 249         for type_parameter in substs.types() {
 250             self.push_type_name(type_parameter, output, debug);
 251             output.push_str(", ");
 252         }
 253
 254         for projection in projections {
 255             let projection = projection.skip_binder();
 256             let name = &self.tcx.associated_item(projection.item_def_id).ident.as_str();
 257             output.push_str(name);
 258             output.push_str("=");
 259             self.push_type_name(projection.ty, output, debug);
 260             output.push_str(", ");
 261         }
 262
 263         for const_parameter in substs.consts() {
 264             self.push_const_name(const_parameter, output, debug);
 265             output.push_str(", ");
 266         }
 267
 268         output.pop();
 269         output.pop();
 270
 271         output.push('>');
 272     }
 273
 274     pub fn push_instance_as_string(
 275         &self,
 276         instance: Instance<'tcx>,
 277         output: &mut String,
 278         debug: bool,
 279     ) {
 280         self.push_def_path(instance.def_id(), output);
 281         self.push_generic_params(instance.substs, iter::empty(), output, debug);
 282     }
 283 }