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| 1 | +use rustc::ty::{ |
| 2 | + TyCtxt, Ty, |
| 3 | + subst::{UnpackedKind, Kind}, |
| 4 | + print::{Printer, PrettyPrinter, Print}, |
| 5 | + self, |
| 6 | +}; |
| 7 | +use rustc::hir::map::{DefPathData, DisambiguatedDefPathData}; |
| 8 | +use rustc::hir::def_id::CrateNum; |
| 9 | +use std::fmt::Write; |
| 10 | +use rustc::mir::interpret::{Allocation, ConstValue}; |
| 11 | + |
| 12 | +struct AbsolutePathPrinter<'a, 'tcx> { |
| 13 | + tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| 14 | + path: String, |
| 15 | +} |
| 16 | + |
| 17 | +impl<'tcx> Printer<'tcx, 'tcx> for AbsolutePathPrinter<'_, 'tcx> { |
| 18 | + type Error = std::fmt::Error; |
| 19 | + |
| 20 | + type Path = Self; |
| 21 | + type Region = Self; |
| 22 | + type Type = Self; |
| 23 | + type DynExistential = Self; |
| 24 | + type Const = Self; |
| 25 | + |
| 26 | + fn tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> { |
| 27 | + self.tcx |
| 28 | + } |
| 29 | + |
| 30 | + fn print_region(self, _region: ty::Region<'_>) -> Result<Self::Region, Self::Error> { |
| 31 | + Ok(self) |
| 32 | + } |
| 33 | + |
| 34 | + fn print_type(self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> { |
| 35 | + match ty.sty { |
| 36 | + // types without identity |
| 37 | + | ty::Bool |
| 38 | + | ty::Char |
| 39 | + | ty::Int(_) |
| 40 | + | ty::Uint(_) |
| 41 | + | ty::Float(_) |
| 42 | + | ty::Str |
| 43 | + | ty::Array(_, _) |
| 44 | + | ty::Slice(_) |
| 45 | + | ty::RawPtr(_) |
| 46 | + | ty::Ref(_, _, _) |
| 47 | + | ty::FnPtr(_) |
| 48 | + | ty::Never |
| 49 | + | ty::Tuple(_) |
| 50 | + | ty::Dynamic(_, _) |
| 51 | + | ty::Adt(..) |
| 52 | + | ty::Foreign(_) |
| 53 | + // should be unreachable, but there's no hurt in printing it (and better than ICEing) |
| 54 | + | ty::Error |
| 55 | + => self.pretty_print_type(ty), |
| 56 | + | ty::Infer(_) |
| 57 | + | ty::Bound(_, _) |
| 58 | + | ty::Param(_) |
| 59 | + | ty::Placeholder(_) |
| 60 | + | ty::Projection(_) |
| 61 | + | ty::UnnormalizedProjection(_) |
| 62 | + | ty::GeneratorWitness(_) |
| 63 | + => bug!( |
| 64 | + "{:#?} in `type_name` should not happen because we are always monomorphized", |
| 65 | + ty, |
| 66 | + ), |
| 67 | + // types with identity (print the module path instead) |
| 68 | + | ty::FnDef(did, substs) |
| 69 | + | ty::Opaque(did, substs) |
| 70 | + => self.print_def_path(did, substs), |
| 71 | + ty::Closure(did, substs) => self.print_def_path(did, substs.substs), |
| 72 | + ty::Generator(did, substs, _) => self.print_def_path(did, substs.substs), |
| 73 | + } |
| 74 | + } |
| 75 | + |
| 76 | + fn print_const( |
| 77 | + self, |
| 78 | + _: &'tcx ty::Const<'tcx>, |
| 79 | + ) -> Result<Self::Const, Self::Error> { |
| 80 | + // don't print constants to the user |
| 81 | + Ok(self) |
| 82 | + } |
| 83 | + |
| 84 | + fn print_dyn_existential( |
| 85 | + mut self, |
| 86 | + predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>, |
| 87 | + ) -> Result<Self::DynExistential, Self::Error> { |
| 88 | + let mut first = true; |
| 89 | + for p in predicates { |
| 90 | + if !first { |
| 91 | + write!(self, "+")?; |
| 92 | + } |
| 93 | + first = false; |
| 94 | + self = p.print(self)?; |
| 95 | + } |
| 96 | + Ok(self) |
| 97 | + } |
| 98 | + |
| 99 | + fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> { |
| 100 | + self.path.push_str(&self.tcx.original_crate_name(cnum).as_str()); |
| 101 | + Ok(self) |
| 102 | + } |
| 103 | + |
| 104 | + fn path_qualified( |
| 105 | + self, |
| 106 | + self_ty: Ty<'tcx>, |
| 107 | + trait_ref: Option<ty::TraitRef<'tcx>>, |
| 108 | + ) -> Result<Self::Path, Self::Error> { |
| 109 | + self.pretty_path_qualified(self_ty, trait_ref) |
| 110 | + } |
| 111 | + |
| 112 | + fn path_append_impl( |
| 113 | + self, |
| 114 | + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, |
| 115 | + _disambiguated_data: &DisambiguatedDefPathData, |
| 116 | + self_ty: Ty<'tcx>, |
| 117 | + trait_ref: Option<ty::TraitRef<'tcx>>, |
| 118 | + ) -> Result<Self::Path, Self::Error> { |
| 119 | + self.pretty_path_append_impl( |
| 120 | + |mut cx| { |
| 121 | + cx = print_prefix(cx)?; |
| 122 | + |
| 123 | + cx.path.push_str("::"); |
| 124 | + |
| 125 | + Ok(cx) |
| 126 | + }, |
| 127 | + self_ty, |
| 128 | + trait_ref, |
| 129 | + ) |
| 130 | + } |
| 131 | + |
| 132 | + fn path_append( |
| 133 | + mut self, |
| 134 | + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, |
| 135 | + disambiguated_data: &DisambiguatedDefPathData, |
| 136 | + ) -> Result<Self::Path, Self::Error> { |
| 137 | + self = print_prefix(self)?; |
| 138 | + |
| 139 | + // Skip `::{{constructor}}` on tuple/unit structs. |
| 140 | + match disambiguated_data.data { |
| 141 | + DefPathData::Ctor => return Ok(self), |
| 142 | + _ => {} |
| 143 | + } |
| 144 | + |
| 145 | + self.path.push_str("::"); |
| 146 | + |
| 147 | + self.path.push_str(&disambiguated_data.data.as_interned_str().as_str()); |
| 148 | + Ok(self) |
| 149 | + } |
| 150 | + |
| 151 | + fn path_generic_args( |
| 152 | + mut self, |
| 153 | + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, |
| 154 | + args: &[Kind<'tcx>], |
| 155 | + ) -> Result<Self::Path, Self::Error> { |
| 156 | + self = print_prefix(self)?; |
| 157 | + let args = args.iter().cloned().filter(|arg| { |
| 158 | + match arg.unpack() { |
| 159 | + UnpackedKind::Lifetime(_) => false, |
| 160 | + _ => true, |
| 161 | + } |
| 162 | + }); |
| 163 | + if args.clone().next().is_some() { |
| 164 | + self.generic_delimiters(|cx| cx.comma_sep(args)) |
| 165 | + } else { |
| 166 | + Ok(self) |
| 167 | + } |
| 168 | + } |
| 169 | +} |
| 170 | +impl PrettyPrinter<'tcx, 'tcx> for AbsolutePathPrinter<'_, 'tcx> { |
| 171 | + fn region_should_not_be_omitted( |
| 172 | + &self, |
| 173 | + _region: ty::Region<'_>, |
| 174 | + ) -> bool { |
| 175 | + false |
| 176 | + } |
| 177 | + fn comma_sep<T>( |
| 178 | + mut self, |
| 179 | + mut elems: impl Iterator<Item = T>, |
| 180 | + ) -> Result<Self, Self::Error> |
| 181 | + where T: Print<'tcx, 'tcx, Self, Output = Self, Error = Self::Error> |
| 182 | + { |
| 183 | + if let Some(first) = elems.next() { |
| 184 | + self = first.print(self)?; |
| 185 | + for elem in elems { |
| 186 | + self.path.push_str(", "); |
| 187 | + self = elem.print(self)?; |
| 188 | + } |
| 189 | + } |
| 190 | + Ok(self) |
| 191 | + } |
| 192 | + |
| 193 | + fn generic_delimiters( |
| 194 | + mut self, |
| 195 | + f: impl FnOnce(Self) -> Result<Self, Self::Error>, |
| 196 | + ) -> Result<Self, Self::Error> { |
| 197 | + write!(self, "<")?; |
| 198 | + |
| 199 | + self = f(self)?; |
| 200 | + |
| 201 | + write!(self, ">")?; |
| 202 | + |
| 203 | + Ok(self) |
| 204 | + } |
| 205 | +} |
| 206 | + |
| 207 | +impl Write for AbsolutePathPrinter<'_, '_> { |
| 208 | + fn write_str(&mut self, s: &str) -> std::fmt::Result { |
| 209 | + Ok(self.path.push_str(s)) |
| 210 | + } |
| 211 | +} |
| 212 | + |
| 213 | +/// Produces an absolute path representation of the given type. See also the documentation on |
| 214 | +/// `std::any::type_name` |
| 215 | +pub fn type_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> &'tcx ty::Const<'tcx> { |
| 216 | + let path = AbsolutePathPrinter { tcx, path: String::new() }.print_type(ty).unwrap().path; |
| 217 | + let len = path.len(); |
| 218 | + let alloc = Allocation::from_byte_aligned_bytes(path.into_bytes(), ()); |
| 219 | + let alloc = tcx.intern_const_alloc(alloc); |
| 220 | + tcx.mk_const(ty::Const { |
| 221 | + val: ConstValue::Slice { |
| 222 | + data: alloc, |
| 223 | + start: 0, |
| 224 | + end: len, |
| 225 | + }, |
| 226 | + ty: tcx.mk_static_str(), |
| 227 | + }) |
| 228 | +} |
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