Use lang items instead of hard-coded paths in HIR lowering

Author: matthewjasper

src/libcore/convert/mod.rs

@@ -381,6 +381,7 @@ pub trait Into<T>: Sized {
 pub trait From<T>: Sized {
     /// Performs the conversion.
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "from_method")]
     fn from(_: T) -> Self;
 }
 

src/libcore/iter/traits/collect.rs

@@ -236,6 +236,7 @@ pub trait IntoIterator {
     /// assert_eq!(None, iter.next());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "into_iter")]
     fn into_iter(self) -> Self::IntoIter;
 }
 

src/libcore/iter/traits/iterator.rs

@@ -127,6 +127,7 @@ pub trait Iterator {
     /// assert_eq!(None, iter.next());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "iter_next")]
     fn next(&mut self) -> Option<Self::Item>;
 
     /// Returns the bounds on the remaining length of the iterator.

src/libcore/ops/range.rs

@@ -41,6 +41,7 @@ use crate::hash::{Hash, Hasher};
 #[doc(alias = "..")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), lang = "range_full")]
 pub struct RangeFull;
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -73,6 +74,7 @@ impl fmt::Debug for RangeFull {
 #[doc(alias = "..")]
 #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), lang = "range")]
 pub struct Range<Idx> {
     /// The lower bound of the range (inclusive).
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -178,6 +180,7 @@ impl<Idx: PartialOrd<Idx>> Range<Idx> {
 #[doc(alias = "..")]
 #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), lang = "range_from")]
 pub struct RangeFrom<Idx> {
     /// The lower bound of the range (inclusive).
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -262,6 +265,7 @@ impl<Idx: PartialOrd<Idx>> RangeFrom<Idx> {
 #[doc(alias = "..")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), lang = "range_to")]
 pub struct RangeTo<Idx> {
     /// The upper bound of the range (exclusive).
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -404,6 +408,7 @@ impl<Idx> RangeInclusive<Idx> {
     #[inline]
     #[rustc_promotable]
     #[rustc_const_stable(feature = "const_range_new", since = "1.32.0")]
+    #[cfg_attr(not(bootstrap), lang = "range_inclusive")]
     pub const fn new(start: Idx, end: Idx) -> Self {
         Self { start, end, is_empty: None }
     }
@@ -607,6 +612,7 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
 #[doc(alias = "..=")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "inclusive_range", since = "1.26.0")]
+#[cfg_attr(not(bootstrap), lang = "range_to_inclusive")]
 pub struct RangeToInclusive<Idx> {
     /// The upper bound of the range (inclusive)
     #[stable(feature = "inclusive_range", since = "1.26.0")]

src/libcore/ops/try.rs

@@ -43,15 +43,18 @@ pub trait Try {
     /// `Try`). Specifically, the value `X::from_error(From::from(e))`
     /// is returned, where `X` is the return type of the enclosing function.
     #[unstable(feature = "try_trait", issue = "42327")]
+    #[cfg_attr(not(bootstrap), lang = "try_into_result")]
     fn into_result(self) -> Result<Self::Ok, Self::Error>;
 
     /// Wrap an error value to construct the composite result. For example,
     /// `Result::Err(x)` and `Result::from_error(x)` are equivalent.
     #[unstable(feature = "try_trait", issue = "42327")]
+    #[cfg_attr(not(bootstrap), lang = "try_from_error")]
     fn from_error(v: Self::Error) -> Self;
 
     /// Wrap an OK value to construct the composite result. For example,
     /// `Result::Ok(x)` and `Result::from_ok(x)` are equivalent.
     #[unstable(feature = "try_trait", issue = "42327")]
+    #[cfg_attr(not(bootstrap), lang = "try_from_ok")]
     fn from_ok(v: Self::Ok) -> Self;
 }

src/libcore/option.rs

@@ -156,9 +156,11 @@ use crate::{
 pub enum Option<T> {
     /// No value
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "option_none")]
     None,
     /// Some value `T`
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "option_some")]
     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
 }
 

src/libcore/pin.rs

@@ -562,6 +562,7 @@ impl<P: Deref> Pin<P> {
     /// [`mem::swap`]: ../../std/mem/fn.swap.html
     #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
+    #[cfg_attr(not(bootstrap), lang = "pin_new_unchecked")]
     pub unsafe fn new_unchecked(pointer: P) -> Pin<P> {
         Pin { pointer }
     }

src/libcore/result.rs

@@ -247,10 +247,12 @@ use crate::ops::{self, Deref, DerefMut};
 pub enum Result<T, E> {
     /// Contains the success value
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "result_ok")]
     Ok(#[stable(feature = "rust1", since = "1.0.0")] T),
 
     /// Contains the error value
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(bootstrap), lang = "result_err")]
     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
 }
 

src/libcore/task/poll.rs

@@ -11,6 +11,7 @@ use crate::result::Result;
 pub enum Poll<T> {
     /// Represents that a value is immediately ready.
     #[stable(feature = "futures_api", since = "1.36.0")]
+    #[cfg_attr(not(bootstrap), lang = "poll_ready")]
     Ready(#[stable(feature = "futures_api", since = "1.36.0")] T),
 
     /// Represents that a value is not ready yet.
@@ -19,6 +20,7 @@ pub enum Poll<T> {
     /// ensure that the current task is scheduled to be awoken when
     /// progress can be made.
     #[stable(feature = "futures_api", since = "1.36.0")]
+    #[cfg_attr(not(bootstrap), lang = "poll_pending")]
     Pending,
 }
 

src/librustc/hir/mod.rs

@@ -8,9 +8,20 @@ pub mod map;
 pub mod upvars;
 
 use crate::ty::query::Providers;
+use crate::ty::TyCtxt;
+use rustc_hir as hir;
+use rustc_hir::def_id::DefId;
+use rustc_hir::lang_item::LangItem;
+use rustc_span::Span;
 
 pub fn provide(providers: &mut Providers<'_>) {
     check_attr::provide(providers);
     map::provide(providers);
     upvars::provide(providers);
 }
+
+impl hir::RequireLangItem for TyCtxt<'_> {
+    fn require_lang_item(self, lang_item: LangItem, span: Span) -> DefId {
+        self.require_lang_item(lang_item, Some(span))
+    }
+}