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Rollup merge of #75675 - davidtwco:symbol-mangling-impl-params, r=eddyb

mangling: mangle impl params w/ v0 scheme

This PR modifies v0 symbol mangling to include all generic parameters from impl blocks (not just those used in the self type) - an alternative fix to #75326.

```
original:
   _RNCNvXCs4fqI2P2rA04_19impl_param_manglingINtB4_3FooppENtNtNtNtCsfnEnqCNU58Z_4core4iter6traits8iterator8Iterator4next0B4_
//        |------------ B4_ ----------------|
// _R (N C (N v (X (C ((s 4fqI2p2rA04_) 19impl_param_mangling)) (I (N t B4_ 3Foo) pp E) (N t (N t (N t (N t (C ((s fnEnqCNU58Z_) 4core)) 4iter) 6traits) 8iterator) 8Iterator)) 4next) 0) B4_

modified:
   _RNvXINICs4fqI2P2rA04_11issue_753260pppEINtB5_3FooppENtNtNtNtCsfnEnqCNU58Z_4core4iter6traits8iterator8Iterator4nextB5_
// _R (N v (X (I (N I (C ((s 4fqI2P2rA04_) 11issue_75326)) 0) ppp E) (I (N t B5_ 3Foo) pp E) (N t (N t (N t (N t (C ((s fnEnqCNU58Z_) 4core)) 4iter) 6traits) 8iterator) 8Iterator)) 4next) B5_
//            |     ^                                              |
//            |     |                                              |
//            |     new impl namespace                             |
```

~~Submitted as a draft as after some discussion w/ @eddyb, I'm going to do some investigation into (yet more alternative) changes to polymorphization that might remove the necessity for this.~~

r? @eddyb
This commit is contained in:
Dylan DPC 2020-10-16 02:10:02 +02:00 committed by GitHub
commit 1643fd86a7
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8 changed files with 159 additions and 44 deletions

View file

@ -291,7 +291,17 @@ impl<'tcx> Instance<'tcx> {
}
pub fn mono(tcx: TyCtxt<'tcx>, def_id: DefId) -> Instance<'tcx> {
Instance::new(def_id, tcx.empty_substs_for_def_id(def_id))
let substs = InternalSubsts::for_item(tcx, def_id, |param, _| match param.kind {
ty::GenericParamDefKind::Lifetime => tcx.lifetimes.re_erased.into(),
ty::GenericParamDefKind::Type { .. } => {
bug!("Instance::mono: {:?} has type parameters", def_id)
}
ty::GenericParamDefKind::Const { .. } => {
bug!("Instance::mono: {:?} has const parameters", def_id)
}
});
Instance::new(def_id, substs)
}
#[inline]

View file

@ -6,9 +6,9 @@ use crate::mir::interpret::{sign_extend, truncate};
use crate::ty::fold::TypeFolder;
use crate::ty::layout::IntegerExt;
use crate::ty::query::TyCtxtAt;
use crate::ty::subst::{GenericArgKind, InternalSubsts, Subst, SubstsRef};
use crate::ty::subst::{GenericArgKind, Subst, SubstsRef};
use crate::ty::TyKind::*;
use crate::ty::{self, DefIdTree, GenericParamDefKind, List, Ty, TyCtxt, TypeFoldable};
use crate::ty::{self, DefIdTree, List, Ty, TyCtxt, TypeFoldable};
use rustc_apfloat::Float as _;
use rustc_ast as ast;
use rustc_attr::{self as attr, SignedInt, UnsignedInt};
@ -509,20 +509,6 @@ impl<'tcx> TyCtxt<'tcx> {
Some(ty::Binder::bind(env_ty))
}
/// Given the `DefId` of some item that has no type or const parameters, make
/// a suitable "empty substs" for it.
pub fn empty_substs_for_def_id(self, item_def_id: DefId) -> SubstsRef<'tcx> {
InternalSubsts::for_item(self, item_def_id, |param, _| match param.kind {
GenericParamDefKind::Lifetime => self.lifetimes.re_erased.into(),
GenericParamDefKind::Type { .. } => {
bug!("empty_substs_for_def_id: {:?} has type parameters", item_def_id)
}
GenericParamDefKind::Const { .. } => {
bug!("empty_substs_for_def_id: {:?} has const parameters", item_def_id)
}
})
}
/// Returns `true` if the node pointed to by `def_id` is a `static` item.
pub fn is_static(self, def_id: DefId) -> bool {
self.static_mutability(def_id).is_some()