Skip to content

a small fn needs_drop refactor #113824

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

Merged
merged 2 commits into from
Jul 18, 2023
Merged

a small fn needs_drop refactor #113824

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
8a08020
exhaustive matches are good
lcnr Jul 17, 2023
d1b4b45
some additional refactor
lcnr Jul 18, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 9 additions & 9 deletions compiler/rustc_middle/src/ty/util.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ use rustc_index::bit_set::GrowableBitSet;
use rustc_macros::HashStable;
use rustc_session::Limit;
use rustc_span::sym;
use rustc_target::abi::{Integer, IntegerType, Size, TargetDataLayout};
use rustc_target::abi::{Integer, IntegerType, Size};
use rustc_target::spec::abi::Abi;
use smallvec::SmallVec;
use std::{fmt, iter};
Expand Down Expand Up @@ -1085,7 +1085,7 @@ impl<'tcx> Ty<'tcx> {
#[inline]
pub fn needs_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
// Avoid querying in simple cases.
match needs_drop_components(self, &tcx.data_layout) {
match needs_drop_components(tcx, self) {
Err(AlwaysRequiresDrop) => true,
Ok(components) => {
let query_ty = match *components {
Expand Down Expand Up @@ -1118,7 +1118,7 @@ impl<'tcx> Ty<'tcx> {
#[inline]
pub fn has_significant_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
// Avoid querying in simple cases.
match needs_drop_components(self, &tcx.data_layout) {
match needs_drop_components(tcx, self) {
Err(AlwaysRequiresDrop) => true,
Ok(components) => {
let query_ty = match *components {
Expand Down Expand Up @@ -1278,10 +1278,10 @@ impl<'tcx> ExplicitSelf<'tcx> {
/// *any* of the returned types need drop. Returns `Err(AlwaysRequiresDrop)` if
/// this type always needs drop.
pub fn needs_drop_components<'tcx>(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,
target_layout: &TargetDataLayout,
) -> Result<SmallVec<[Ty<'tcx>; 2]>, AlwaysRequiresDrop> {
match ty.kind() {
match *ty.kind() {
ty::Infer(ty::FreshIntTy(_))
| ty::Infer(ty::FreshFloatTy(_))
| ty::Bool
Expand All @@ -1303,11 +1303,11 @@ pub fn needs_drop_components<'tcx>(

ty::Dynamic(..) | ty::Error(_) => Err(AlwaysRequiresDrop),

ty::Slice(ty) => needs_drop_components(*ty, target_layout),
ty::Slice(ty) => needs_drop_components(tcx, ty),
ty::Array(elem_ty, size) => {
match needs_drop_components(*elem_ty, target_layout) {
match needs_drop_components(tcx, elem_ty) {
Ok(v) if v.is_empty() => Ok(v),
res => match size.try_to_bits(target_layout.pointer_size) {
res => match size.try_to_target_usize(tcx) {
// Arrays of size zero don't need drop, even if their element
// type does.
Some(0) => Ok(SmallVec::new()),
Expand All @@ -1321,7 +1321,7 @@ pub fn needs_drop_components<'tcx>(
}
// If any field needs drop, then the whole tuple does.
ty::Tuple(fields) => fields.iter().try_fold(SmallVec::new(), move |mut acc, elem| {
acc.extend(needs_drop_components(elem, target_layout)?);
acc.extend(needs_drop_components(tcx, elem)?);
Ok(acc)
}),

Expand Down
30 changes: 27 additions & 3 deletions compiler/rustc_ty_utils/src/needs_drop.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,7 @@ where
return Some(Err(AlwaysRequiresDrop));
}

let components = match needs_drop_components(ty, &tcx.data_layout) {
let components = match needs_drop_components(tcx, ty) {
Err(e) => return Some(Err(e)),
Ok(components) => components,
};
Expand Down Expand Up @@ -160,7 +160,7 @@ where
queue_type(self, required);
}
}
ty::Array(..) | ty::Alias(..) | ty::Param(_) => {
ty::Alias(..) | ty::Array(..) | ty::Placeholder(_) | ty::Param(_) => {
if ty == component {
// Return the type to the caller: they may be able
// to normalize further than we can.
Expand All @@ -172,7 +172,31 @@ where
queue_type(self, component);
}
}
_ => return Some(Err(AlwaysRequiresDrop)),

ty::Foreign(_) | ty::Dynamic(..) => {
return Some(Err(AlwaysRequiresDrop));
}

ty::Bool
| ty::Char
| ty::Int(_)
| ty::Uint(_)
| ty::Float(_)
| ty::Str
| ty::Slice(_)
| ty::Ref(..)
| ty::RawPtr(..)
| ty::FnDef(..)
| ty::FnPtr(..)
| ty::Tuple(_)
| ty::Bound(..)
| ty::GeneratorWitness(..)
| ty::GeneratorWitnessMIR(..)
| ty::Never
| ty::Infer(_)
| ty::Error(_) => {
bug!("unexpected type returned by `needs_drop_components`: {component}")
}
}
}
}
Expand Down