Skip to content

Remove deprecated lang items #44526

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 5 commits into from
Sep 14, 2017
Merged

Remove deprecated lang items #44526

Show file tree
Hide file tree
Changes from 4 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
4738231
Remove deprecated lang items
leoyvens Sep 12, 2017
74107f9
Remove require_owned_box
leoyvens Sep 13, 2017
ab30b6a
Refactor how to get a lang item's name
leoyvens Sep 13, 2017
c2fb70b
Refactor fn_trait_kind
leoyvens Sep 13, 2017
9218e44
Fix initial review
leoyvens Sep 13, 2017
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
55 changes: 15 additions & 40 deletions src/librustc/middle/lang_items.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,14 @@ enum_from_u32! {
}
}

impl LangItem {
fn name(self) -> &'static str {
match self {
$( $variant => $name, )*
}
}
}

pub struct LanguageItems {
pub items: Vec<Option<DefId>>,
pub missing: Vec<LangItem>,
Expand All @@ -65,42 +73,17 @@ impl LanguageItems {
&*self.items
}

pub fn item_name(index: usize) -> &'static str {
let item: Option<LangItem> = LangItem::from_u32(index as u32);
match item {
$( Some($variant) => $name, )*
None => "???"
}
}

pub fn require(&self, it: LangItem) -> Result<DefId, String> {
match self.items[it as usize] {
Some(id) => Ok(id),
None => {
Err(format!("requires `{}` lang_item",
LanguageItems::item_name(it as usize)))
}
}
}

pub fn require_owned_box(&self) -> Result<DefId, String> {
self.require(OwnedBoxLangItem)
self.items[it as usize].ok_or(format!("requires `{}` lang_item", it.name()))
Copy link
Member

Choose a reason for hiding this comment

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

Please make this an ok_or_else since otherwise we allocate a String each name, and also go through a lookup table to get the name of the lang item, both of which are somewhat expensive operations to do for lang item lookup.

}

pub fn fn_trait_kind(&self, id: DefId) -> Option<ty::ClosureKind> {
let def_id_kinds = [
(self.fn_trait(), ty::ClosureKind::Fn),
(self.fn_mut_trait(), ty::ClosureKind::FnMut),
(self.fn_once_trait(), ty::ClosureKind::FnOnce),
];

for &(opt_def_id, kind) in &def_id_kinds {
if Some(id) == opt_def_id {
return Some(kind);
}
match Some(id) {
x if x == self.fn_trait() => Some(ty::ClosureKind::Fn),
x if x == self.fn_mut_trait() => Some(ty::ClosureKind::FnMut),
x if x == self.fn_once_trait() => Some(ty::ClosureKind::FnOnce),
Copy link
Member

Choose a reason for hiding this comment

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

nit: Extra space after the =>.

_ => None
}

None
}

$(
Expand Down Expand Up @@ -162,7 +145,7 @@ impl<'a, 'tcx> LanguageItemCollector<'a, 'tcx> {
// Check for duplicates.
match self.items.items[item_index] {
Some(original_def_id) if original_def_id != item_def_id => {
let name = LanguageItems::item_name(item_index);
let name = LangItem::from_u32(item_index as u32).unwrap().name();
let mut err = match self.tcx.hir.span_if_local(item_def_id) {
Some(span) => struct_span_err!(
self.tcx.sess,
Expand Down Expand Up @@ -327,14 +310,6 @@ language_item_table! {

PhantomDataItem, "phantom_data", phantom_data;

// Deprecated:
CovariantTypeItem, "covariant_type", covariant_type;
ContravariantTypeItem, "contravariant_type", contravariant_type;
InvariantTypeItem, "invariant_type", invariant_type;
CovariantLifetimeItem, "covariant_lifetime", covariant_lifetime;
ContravariantLifetimeItem, "contravariant_lifetime", contravariant_lifetime;
InvariantLifetimeItem, "invariant_lifetime", invariant_lifetime;

NonZeroItem, "non_zero", non_zero;

DebugTraitLangItem, "debug_trait", debug_trait;
Expand Down
9 changes: 0 additions & 9 deletions src/librustc_typeck/variance/terms.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -98,15 +98,6 @@ fn lang_items(tcx: TyCtxt) -> Vec<(ast::NodeId, Vec<ty::Variance>)> {
let all = vec![
(lang_items.phantom_data(), vec![ty::Covariant]),
(lang_items.unsafe_cell_type(), vec![ty::Invariant]),

// Deprecated:
(lang_items.covariant_type(), vec![ty::Covariant]),
(lang_items.contravariant_type(), vec![ty::Contravariant]),
(lang_items.invariant_type(), vec![ty::Invariant]),
(lang_items.covariant_lifetime(), vec![ty::Covariant]),
(lang_items.contravariant_lifetime(), vec![ty::Contravariant]),
(lang_items.invariant_lifetime(), vec![ty::Invariant]),

];

all.into_iter() // iterating over (Option<DefId>, Variance)
Expand Down