Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Add const generics support for pattern types #123689

Merged
merged 2 commits into from Apr 10, 2024
Merged

Add const generics support for pattern types #123689

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a2bdb99
Add const generics failing test for pattern types
spastorino Apr 9, 2024
30c546a
Handle const generic pattern types
spastorino Feb 20, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
18 changes: 18 additions & 0 deletions compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
View file
Open in desktop
Expand Up @@ -2223,6 +2223,24 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
Err(LitToConstError::TypeError) => todo!(),
}
}

hir::ExprKind::Path(hir::QPath::Resolved(
_,
&hir::Path {
res: Res::Def(DefKind::ConstParam, def_id), ..
},
)) => {
Copy link
Member

@fmease fmease Apr 12, 2024 •
edited

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note that we're missing a call to prohibit_generic_args here. Right now, we permit:

pattern_type!(u32 is START::<(), i32, 2>..=END::<_>)

where START and END are u32s like in the UI test.

While we could add this check, this just reinforces oli's point: #123689 (comment), Zulip discussion.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Just noticed this while reviewing an unrelated PR.

let ty = tcx
.type_of(def_id)
.no_bound_vars()
.expect("const parameter types cannot be generic");
let item_def_id = tcx.parent(def_id);
let generics = tcx.generics_of(item_def_id);
let index = generics.param_def_id_to_index[&def_id];
let name = tcx.item_name(def_id);
ty::Const::new_param(tcx, ty::ParamConst::new(index, name), ty)
}

_ => {
let err = tcx
.dcx()
Expand Down
8 changes: 6 additions & 2 deletions compiler/rustc_ty_utils/src/layout.rs
View file
Open in desktop
Expand Up @@ -133,10 +133,14 @@ fn layout_of_uncached<'tcx>(
ty::PatternKind::Range { start, end, include_end } => {
if let Abi::Scalar(scalar) | Abi::ScalarPair(scalar, _) = &mut layout.abi {
if let Some(start) = start {
scalar.valid_range_mut().start = start.eval_bits(tcx, param_env);
scalar.valid_range_mut().start = start
.try_eval_bits(tcx, param_env)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
}
if let Some(end) = end {
let mut end = end.eval_bits(tcx, param_env);
let mut end = end
.try_eval_bits(tcx, param_env)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
if !include_end {
end = end.wrapping_sub(1);
}
Expand Down
13 changes: 13 additions & 0 deletions tests/ui/type/pattern_types/const_generics.rs
View file
Open in desktop
@@ -0,0 +1,13 @@
//@ check-pass

#![feature(pattern_types)]
#![feature(core_pattern_types)]
#![feature(core_pattern_type)]

use std::pat::pattern_type;

trait Foo {}

impl<const START: u32, const END: u32> Foo for pattern_type!(u32 is START..=END) {}

fn main() {}