diff options
| -rw-r--r-- | compiler/rustc_symbol_mangling/src/v0.rs | 59 | ||||
| -rw-r--r-- | tests/ui/const-generics/unsized_const_params/symbol_mangling_v0_str.rs | 24 |
2 files changed, 51 insertions, 32 deletions
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs index ba35a37c32c..1e8d7697fb7 100644 --- a/compiler/rustc_symbol_mangling/src/v0.rs +++ b/compiler/rustc_symbol_mangling/src/v0.rs @@ -593,45 +593,40 @@ impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> { let _ = write!(self.out, "{bits:x}_"); } + // Handle `str` as partial support for unsized constants + ty::Str => { + let tcx = self.tcx(); + // HACK(jaic1): hide the `str` type behind a reference + // for the following transformation from valtree to raw bytes + let ref_ty = Ty::new_imm_ref(tcx, tcx.lifetimes.re_static, ct_ty); + let slice = valtree.try_to_raw_bytes(tcx, ref_ty).unwrap_or_else(|| { + bug!("expected to get raw bytes from valtree {:?} for type {:}", valtree, ct_ty) + }); + let s = std::str::from_utf8(slice).expect("non utf8 str from MIR interpreter"); + + // "e" for str as a basic type + self.push("e"); + + // FIXME(eddyb) use a specialized hex-encoding loop. + for byte in s.bytes() { + let _ = write!(self.out, "{byte:02x}"); + } + + self.push("_"); + } + // FIXME(valtrees): Remove the special case for `str` // here and fully support unsized constants. - ty::Ref(_, inner_ty, mutbl) => { + ty::Ref(_, _, mutbl) => { self.push(match mutbl { hir::Mutability::Not => "R", hir::Mutability::Mut => "Q", }); - match inner_ty.kind() { - ty::Str if mutbl.is_not() => { - let slice = - valtree.try_to_raw_bytes(self.tcx(), ct_ty).unwrap_or_else(|| { - bug!( - "expected to get raw bytes from valtree {:?} for type {:}", - valtree, - ct_ty - ) - }); - let s = - std::str::from_utf8(slice).expect("non utf8 str from MIR interpreter"); - - self.push("e"); - - // FIXME(eddyb) use a specialized hex-encoding loop. - for byte in s.bytes() { - let _ = write!(self.out, "{byte:02x}"); - } - - self.push("_"); - } - _ => { - let pointee_ty = ct_ty - .builtin_deref(true) - .expect("tried to dereference on non-ptr type"); - let dereferenced_const = - ty::Const::new_value(self.tcx, valtree, pointee_ty); - dereferenced_const.print(self)?; - } - } + let pointee_ty = + ct_ty.builtin_deref(true).expect("tried to dereference on non-ptr type"); + let dereferenced_const = ty::Const::new_value(self.tcx, valtree, pointee_ty); + dereferenced_const.print(self)?; } ty::Array(..) | ty::Tuple(..) | ty::Adt(..) | ty::Slice(_) => { diff --git a/tests/ui/const-generics/unsized_const_params/symbol_mangling_v0_str.rs b/tests/ui/const-generics/unsized_const_params/symbol_mangling_v0_str.rs new file mode 100644 index 00000000000..359126f1251 --- /dev/null +++ b/tests/ui/const-generics/unsized_const_params/symbol_mangling_v0_str.rs @@ -0,0 +1,24 @@ +//@ check-pass +//@ compile-flags: -Csymbol-mangling-version=v0 +#![allow(incomplete_features)] +#![feature(unsized_const_params)] + +// Regression test for #116303 + +#[derive(PartialEq, Eq)] +struct MyStr(str); +impl std::marker::UnsizedConstParamTy for MyStr {} + +fn function_with_my_str<const S: &'static MyStr>() -> &'static MyStr { + S +} + +impl MyStr { + const fn new(s: &'static str) -> &'static MyStr { + unsafe { std::mem::transmute(s) } + } +} + +pub fn main() { + let f = function_with_my_str::<{ MyStr::new("hello") }>(); +} |