1
Fork 0
Commit graph

22 commits

Author SHA1 Message Date
Nicholas Nethercote
e9a0c429c5 Overhaul TyS and Ty.
Specifically, change `Ty` from this:
```
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
```
to this
```
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
```
There are two benefits to this.
- It's now a first class type, so we can define methods on it. This
  means we can move a lot of methods away from `TyS`, leaving `TyS` as a
  barely-used type, which is appropriate given that it's not meant to
  be used directly.
- The uniqueness requirement is now explicit, via the `Interned` type.
  E.g. the pointer-based `Eq` and `Hash` comes from `Interned`, rather
  than via `TyS`, which wasn't obvious at all.

Much of this commit is boring churn. The interesting changes are in
these files:
- compiler/rustc_middle/src/arena.rs
- compiler/rustc_middle/src/mir/visit.rs
- compiler/rustc_middle/src/ty/context.rs
- compiler/rustc_middle/src/ty/mod.rs

Specifically:
- Most mentions of `TyS` are removed. It's very much a dumb struct now;
  `Ty` has all the smarts.
- `TyS` now has `crate` visibility instead of `pub`.
- `TyS::make_for_test` is removed in favour of the static `BOOL_TY`,
  which just works better with the new structure.
- The `Eq`/`Ord`/`Hash` impls are removed from `TyS`. `Interned`s impls
  of `Eq`/`Hash` now suffice. `Ord` is now partly on `Interned`
  (pointer-based, for the `Equal` case) and partly on `TyS`
  (contents-based, for the other cases).
- There are many tedious sigil adjustments, i.e. adding or removing `*`
  or `&`. They seem to be unavoidable.
2022-02-15 16:03:24 +11:00
Michael Goulet
a431174c23 add tainted_by_errors to mir::Body 2022-02-11 12:45:51 -08:00
Ellen
71bbb603f4 initial revert 2022-01-15 01:16:55 +00:00
Matthias Krüger
57a4f4a634
Rollup merge of #90102 - nbdd0121:box3, r=jonas-schievink
Remove `NullOp::Box`

Follow up of #89030 and MCP rust-lang/compiler-team#460.

~1 month later nothing seems to be broken, apart from a small regression that #89332 (1aac85bb716c09304b313d69d30d74fe7e8e1a8e) shows could be regained by remvoing the diverging path, so it shall be safe to continue and remove `NullOp::Box` completely.

r? `@jonas-schievink`
`@rustbot` label T-compiler
2022-01-03 14:44:15 +01:00
LegionMammal978
a19eaf3542 Remove in_band_lifetimes from rustc_const_eval
See #91867 for more information.
2021-12-13 22:39:00 -05:00
Dylan MacKenzie
fd18b45e11 Update passes with new interface 2021-12-02 17:31:38 -08:00
Dylan MacKenzie
188d670125 Don't re-export MirPass 2021-11-29 12:58:15 -08:00
Tomasz Miąsko
59edb9d382 Remove Candidate::source_info 2021-11-05 21:31:25 +01:00
Tomasz Miąsko
7bc827b34b Refactor single variant Candidate enum into a struct
`Candidate` enum has only a single `Ref` variant.  Refactor it into a
struct and reduce overall indentation of the code by two levels.

No functional changes.
2021-11-05 21:31:18 +01:00
Tomasz Miąsko
3a95338f31 Remove unnecessary Option from promote_candidate return type 2021-10-31 00:00:00 +00:00
Gary Guo
cc4345a1c5 Clean up special function const checks
Mark them as const and `#[rustc_do_not_const_check]` instead of hard-coding
them in const-eval checks.
2021-10-25 17:32:01 +01:00
Gary Guo
1b7f5a3818 Remove NullOp::Box 2021-10-20 19:42:35 +01:00
Tomasz Miąsko
915a581bcb Do not promote values with const drop that need to be dropped
Changes from #88558 allowed using `~const Drop` in constants by
introducing a new `NeedsNonConstDrop` qualif.

The new qualif was also used for promotion purposes, and allowed
promotion to happen for values that needs to be dropped but which
do have a const drop impl.

Since for promoted the drop implementation is never executed,
this lead to observable change in behaviour. For example:

```rust

struct Panic();

impl const Drop for Panic {
    fn drop(&mut self) {
        panic!();
    }
}

fn main() {
    let _ = &Panic();
}
```

Restore the use of `NeedsDrop` qualif during promotion to avoid the issue.
2021-10-18 21:56:57 +02:00
Deadbeef
5387b6542f
Add const_eval_select intrinsic 2021-10-12 05:42:23 +00:00
Manish Goregaokar
743e842afb
Rollup merge of #88963 - fee1-dead:const-iterator, r=oli-obk
Coerce const FnDefs to implement const Fn traits

You can now pass a FnDef to a function expecting `F` where `F: ~const FnTrait`.

r? ``@oli-obk``

``@rustbot`` label T-compiler F-const_trait_impl
2021-10-01 14:46:48 -07:00
Gary Guo
c38da2e0a3 Introduce Rvalue::ShallowInitBox 2021-09-25 01:08:41 +01:00
Deadbeef
f8aa73d3dd
Coerce const FnDefs to implement const Fn traits 2021-09-15 11:48:27 +00:00
Deadbeef
d3f981b144
Move is_const_fn to under TyCtxt 2021-09-15 11:27:34 +00:00
bors
cdeba02ff7 Auto merge of #88558 - fee1-dead:const-drop, r=oli-obk
Const drop

The changes are pretty primitive at this point. But at least it works. ^-^

Problems with the current change that I can think of now:
 - [x] `~const Drop` shouldn't change anything in the non-const world.
 - [x] types that do not have drop glues shouldn't fail to satisfy `~const Drop` in const contexts. `struct S { a: u8, b: u16 }` This might not fail for `needs_non_const_drop`, but it will fail in `rustc_trait_selection`.
 - [x] The current change accepts types that have `const Drop` impls but have non-const `Drop` glue.

Fixes #88424.

Significant Changes:

- `~const Drop` is no longer treated as a normal trait bound. In non-const contexts, this bound has no effect, but in const contexts, this restricts the input type and all of its transitive fields to either a) have a `const Drop` impl or b) can be trivially dropped (i.e. no drop glue)
- `T: ~const Drop` will not be linted like `T: Drop`.
- Instead of recursing and iterating through the type in `rustc_mir::transform::check_consts`, we use the trait system to special case `~const Drop`. See [`rustc_trait_selection::...::candidate_assembly#assemble_const_drop_candidates`](https://github.com/fee1-dead/rust/blob/const-drop/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs#L817) and others.

Changes not related to `const Drop`ping and/or changes that are insignificant:

 - `Node.constness_for_typeck` no longer returns `hir::Constness::Const` for type aliases in traits. This was previously used to hack how we determine default bound constness for items. But because we now use an explicit opt-in, it is no longer needed.
 - Removed `is_const_impl_raw` query. We have `impl_constness`, and the only existing use of that query uses `HirId`, which means we can just operate it with hir.
 - `ty::Destructor` now has a field `constness`, which represents the constness of the destructor.

r? `@oli-obk`
2021-09-15 03:51:03 +00:00
Gary Guo
1c3409f333 Introduce NullOp::AlignOf 2021-09-13 00:08:35 +01:00
Deadbeef
104e40fb74
Const dropping 2021-09-09 05:21:29 +00:00
Camille GILLOT
c5fc2609f0 Rename rustc_mir to rustc_const_eval. 2021-09-07 20:46:26 +02:00
Renamed from compiler/rustc_mir/src/transform/promote_consts.rs (Browse further)