hir: introduce lang items for AST lowering

davidtwco · matthewjasper · davidtwco · commit 7dee5f824dad · 2020-08-16T15:42:23.000+01:00
This commit adds new lang items which will be used in AST lowering once
`QPath::LangItem` is introduced.

Co-authored-by: Matthew Jasper &lt;mjjasper1@gmail.com&gt;
Signed-off-by: David Wood &lt;david@davidtw.co&gt;
diff --git a/library/core/src/convert/mod.rs b/library/core/src/convert/mod.rs
@@ -385,6 +385,7 @@ pub trait Into<T>: Sized {
 ))]
 pub trait From<T>: Sized {
     /// Performs the conversion.
+    #[cfg_attr(not(bootstrap), lang = "from")]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn from(_: T) -> Self;
 }
diff --git a/library/core/src/future/future.rs b/library/core/src/future/future.rs
@@ -96,6 +96,7 @@ pub trait Future {
     /// [`Context`]: ../task/struct.Context.html
     /// [`Waker`]: ../task/struct.Waker.html
     /// [`Waker::wake`]: ../task/struct.Waker.html#method.wake
+    #[cfg_attr(not(bootstrap), lang = "poll")]
     #[stable(feature = "futures_api", since = "1.36.0")]
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>;
 }
diff --git a/library/core/src/future/mod.rs b/library/core/src/future/mod.rs
@@ -53,6 +53,7 @@ unsafe impl Sync for ResumeTy {}
 /// This function returns a `GenFuture` underneath, but hides it in `impl Trait` to give
 /// better error messages (`impl Future` rather than `GenFuture<[closure.....]>`).
 // This is `const` to avoid extra errors after we recover from `const async fn`
+#[cfg_attr(not(bootstrap), lang = "from_generator")]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 #[inline]
@@ -85,6 +86,7 @@ where
     GenFuture(gen)
 }
 
+#[cfg_attr(not(bootstrap), lang = "get_context")]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 #[inline]
diff --git a/library/core/src/iter/traits/collect.rs b/library/core/src/iter/traits/collect.rs
@@ -235,6 +235,7 @@ pub trait IntoIterator {
     /// assert_eq!(Some(3), iter.next());
     /// assert_eq!(None, iter.next());
     /// ```
+    #[cfg_attr(not(bootstrap), lang = "into_iter")]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn into_iter(self) -> Self::IntoIter;
 }
diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs
@@ -129,6 +129,7 @@ pub trait Iterator {
     /// assert_eq!(None, iter.next());
     /// assert_eq!(None, iter.next());
     /// ```
+    #[cfg_attr(not(bootstrap), lang = "next")]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn next(&mut self) -> Option<Self::Item>;
 
diff --git a/library/core/src/ops/range.rs b/library/core/src/ops/range.rs
@@ -38,6 +38,7 @@ use crate::hash::Hash;
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[cfg_attr(not(bootstrap), lang = "RangeFull")]
 #[doc(alias = "..")]
 #[derive(Copy, Clone, Default, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -70,6 +71,7 @@ impl fmt::Debug for RangeFull {
 /// assert_eq!(arr[1.. 3], [  1,2    ]);  // Range
 /// assert_eq!(arr[1..=3], [  1,2,3  ]);
 /// ```
+#[cfg_attr(not(bootstrap), lang = "Range")]
 #[doc(alias = "..")]
 #[derive(Clone, Default, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -178,6 +180,7 @@ impl<Idx: PartialOrd<Idx>> Range<Idx> {
 /// ```
 ///
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
+#[cfg_attr(not(bootstrap), lang = "RangeFrom")]
 #[doc(alias = "..")]
 #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -260,6 +263,7 @@ impl<Idx: PartialOrd<Idx>> RangeFrom<Idx> {
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[cfg_attr(not(bootstrap), lang = "RangeTo")]
 #[doc(alias = "..")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -328,6 +332,7 @@ impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
 /// assert_eq!(arr[1.. 3], [  1,2    ]);
 /// assert_eq!(arr[1..=3], [  1,2,3  ]);  // RangeInclusive
 /// ```
+#[cfg_attr(not(bootstrap), lang = "RangeInclusive")]
 #[doc(alias = "..=")]
 #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "inclusive_range", since = "1.26.0")]
@@ -359,6 +364,7 @@ impl<Idx> RangeInclusive<Idx> {
     ///
     /// assert_eq!(3..=5, RangeInclusive::new(3, 5));
     /// ```
+    #[cfg_attr(not(bootstrap), lang = "range_inclusive_new")]
     #[stable(feature = "inclusive_range_methods", since = "1.27.0")]
     #[inline]
     #[rustc_promotable]
@@ -555,6 +561,7 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[cfg_attr(not(bootstrap), lang = "RangeToInclusive")]
 #[doc(alias = "..=")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "inclusive_range", since = "1.26.0")]
diff --git a/library/core/src/ops/try.rs b/library/core/src/ops/try.rs
@@ -43,16 +43,19 @@ pub trait Try {
     /// in the return type of the enclosing scope (which must itself implement
     /// `Try`). Specifically, the value `X::from_error(From::from(e))`
     /// is returned, where `X` is the return type of the enclosing function.
+    #[cfg_attr(not(bootstrap), lang = "into_result")]
     #[unstable(feature = "try_trait", issue = "42327")]
     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.
+    #[cfg_attr(not(bootstrap), lang = "from_error")]
     #[unstable(feature = "try_trait", issue = "42327")]
     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.
+    #[cfg_attr(not(bootstrap), lang = "from_ok")]
     #[unstable(feature = "try_trait", issue = "42327")]
     fn from_ok(v: Self::Ok) -> Self;
 }
diff --git a/library/core/src/option.rs b/library/core/src/option.rs
@@ -144,9 +144,11 @@ use crate::{
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Option<T> {
     /// No value
+    #[cfg_attr(not(bootstrap), lang = "None")]
     #[stable(feature = "rust1", since = "1.0.0")]
     None,
     /// Some value `T`
+    #[cfg_attr(not(bootstrap), lang = "Some")]
     #[stable(feature = "rust1", since = "1.0.0")]
     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
 }
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
@@ -562,6 +562,7 @@ impl<P: Deref> Pin<P> {
     ///  ```
     ///
     /// [`mem::swap`]: ../../std/mem/fn.swap.html
+    #[cfg_attr(not(bootstrap), lang = "new_unchecked")]
     #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
     pub unsafe fn new_unchecked(pointer: P) -> Pin<P> {
diff --git a/library/core/src/result.rs b/library/core/src/result.rs
@@ -246,10 +246,12 @@ use crate::{convert, fmt};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Result<T, E> {
     /// Contains the success value
+    #[cfg_attr(not(bootstrap), lang = "Ok")]
     #[stable(feature = "rust1", since = "1.0.0")]
     Ok(#[stable(feature = "rust1", since = "1.0.0")] T),
 
     /// Contains the error value
+    #[cfg_attr(not(bootstrap), lang = "Err")]
     #[stable(feature = "rust1", since = "1.0.0")]
     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
 }
diff --git a/library/core/src/task/poll.rs b/library/core/src/task/poll.rs
@@ -10,6 +10,7 @@ use crate::result::Result;
 #[stable(feature = "futures_api", since = "1.36.0")]
 pub enum Poll<T> {
     /// Represents that a value is immediately ready.
+    #[cfg_attr(not(bootstrap), lang = "Ready")]
     #[stable(feature = "futures_api", since = "1.36.0")]
     Ready(#[stable(feature = "futures_api", since = "1.36.0")] T),
 
@@ -18,6 +19,7 @@ pub enum Poll<T> {
     /// When a function returns `Pending`, the function *must* also
     /// ensure that the current task is scheduled to be awoken when
     /// progress can be made.
+    #[cfg_attr(not(bootstrap), lang = "Pending")]
     #[stable(feature = "futures_api", since = "1.36.0")]
     Pending,
 }
diff --git a/src/librustc_hir/lang_items.rs b/src/librustc_hir/lang_items.rs
@@ -10,7 +10,7 @@
 pub use self::LangItem::*;
 
 use crate::def_id::DefId;
-use crate::Target;
+use crate::{MethodKind, Target};
 
 use rustc_ast::ast;
 use rustc_data_structures::fx::FxHashMap;
@@ -307,4 +307,38 @@ language_item_table! {
     CountCodeRegionFnLangItem,         sym::count_code_region,         count_code_region_fn,         Target::Fn;
     CoverageCounterAddFnLangItem,      sym::coverage_counter_add,      coverage_counter_add_fn,      Target::Fn;
     CoverageCounterSubtractFnLangItem, sym::coverage_counter_subtract, coverage_counter_subtract_fn, Target::Fn;
+
+    // Language items from AST lowering
+    TryFromError,                  sym::from_error,         from_error_fn,           Target::Method(MethodKind::Trait { body: false });
+    TryFromOk,                     sym::from_ok,            from_ok_fn,              Target::Method(MethodKind::Trait { body: false });
+    TryIntoResult,                 sym::into_result,        into_result_fn,          Target::Method(MethodKind::Trait { body: false });
+
+    PollReady,                     sym::Ready,              poll_ready_variant,      Target::Variant;
+    PollPending,                   sym::Pending,            poll_pending_variant,    Target::Variant;
+
+    FromGenerator,                 sym::from_generator,     from_generator_fn,       Target::Fn;
+    GetContext,                    sym::get_context,        get_context_fn,          Target::Fn;
+
+    FuturePoll,                    sym::poll,               future_poll_fn,          Target::Method(MethodKind::Trait { body: false });
+
+    FromFrom,                      sym::from,               from_fn,                 Target::Method(MethodKind::Trait { body: false });
+
+    OptionSome,                    sym::Some,               option_some_variant,     Target::Variant;
+    OptionNone,                    sym::None,               option_none_variant,     Target::Variant;
+
+    ResultOk,                      sym::Ok,                 result_ok_variant,       Target::Variant;
+    ResultErr,                     sym::Err,                result_err_variant,      Target::Variant;
+
+    IntoIterIntoIter,              sym::into_iter,          into_iter_fn,            Target::Method(MethodKind::Trait { body: false });
+    IteratorNext,                  sym::next,               next_fn,                 Target::Method(MethodKind::Trait { body: false});
+
+    PinNewUnchecked,               sym::new_unchecked,      new_unchecked_fn,        Target::Method(MethodKind::Inherent);
+
+    RangeFrom,                     sym::RangeFrom,           range_from_struct,          Target::Struct;
+    RangeFull,                     sym::RangeFull,           range_full_struct,          Target::Struct;
+    RangeInclusiveStruct,          sym::RangeInclusive,      range_inclusive_struct,     Target::Struct;
+    RangeInclusiveNew,             sym::range_inclusive_new, range_inclusive_new_method, Target::Method(MethodKind::Inherent);
+    Range,                         sym::Range,               range_struct,               Target::Struct;
+    RangeToInclusive,              sym::RangeToInclusive,    range_to_inclusive_struct,  Target::Struct;
+    RangeTo,                       sym::RangeTo,             range_to_struct,            Target::Struct;
 }
diff --git a/src/librustc_span/symbol.rs b/src/librustc_span/symbol.rs
@@ -706,6 +706,7 @@ symbols! {
         never_type,
         never_type_fallback,
         new,
+        new_unchecked,
         next,
         nll,
         no,
@@ -828,6 +829,7 @@ symbols! {
         quad_precision_float,
         question_mark,
         quote,
+        range_inclusive_new,
         raw_dylib,
         raw_identifiers,
         raw_ref_op,

Original file line number	Diff line number	Diff line change
`@@ -385,6 +385,7 @@ pub trait Into<T>: Sized {`
`385`	`385`	`))]`
`386`	`386`	`pub trait From<T>: Sized {`
`387`	`387`	`/// Performs the conversion.`
	`388`	`+ #[cfg_attr(not(bootstrap), lang = "from")]`
`388`	`389`	`#[stable(feature = "rust1", since = "1.0.0")]`
`389`	`390`	`fn from(_: T) -> Self;`
`390`	`391`	`}`
Original file line number	Diff line number	Diff line change
`@@ -96,6 +96,7 @@ pub trait Future {`
`96`	`96`	/// [`Context`]: ../task/struct.Context.html
`97`	`97`	/// [`Waker`]: ../task/struct.Waker.html
`98`	`98`	/// [`Waker::wake`]: ../task/struct.Waker.html#method.wake
	`99`	`+ #[cfg_attr(not(bootstrap), lang = "poll")]`
`99`	`100`	`#[stable(feature = "futures_api", since = "1.36.0")]`
`100`	`101`	`fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>;`
`101`	`102`	`}`
Original file line number	Diff line number	Diff line change
`@@ -235,6 +235,7 @@ pub trait IntoIterator {`
`235`	`235`	`/// assert_eq!(Some(3), iter.next());`
`236`	`236`	`/// assert_eq!(None, iter.next());`
`237`	`237`	/// ```
	`238`	`+ #[cfg_attr(not(bootstrap), lang = "into_iter")]`
`238`	`239`	`#[stable(feature = "rust1", since = "1.0.0")]`
`239`	`240`	`fn into_iter(self) -> Self::IntoIter;`
`240`	`241`	`}`