Auto merge of #94860 - Dylan-DPC:rollup-n06j8h6, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #87618 (Add missing documentation for std::char types)
 - #94769 (Collapse blanket and auto-trait impls by default)
 - #94798 (`parse_tt` refactorings)
 - #94818 (Rename `IntoFuture::Future` to `IntoFuture::IntoFuture`)
 - #94827 (CTFE/Miri: detect out-of-bounds pointers in offset_from)
 - #94838 (Make float parsing docs more comprehensive)
 - #94839 (Suggest using double colon when a struct field type include single colon)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -307,53 +307,57 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 self.write_pointer(offset_ptr, dest)?;
             }
             sym::ptr_offset_from => {
-                let a = self.read_immediate(&args[0])?.to_scalar()?;
+                let a = self.read_pointer(&args[0])?;
-                let b = self.read_immediate(&args[1])?.to_scalar()?;
+                let b = self.read_pointer(&args[1])?;
 
                 // Special case: if both scalars are *equal integers*
                 // and not null, we pretend there is an allocation of size 0 right there,
                 // and their offset is 0. (There's never a valid object at null, making it an
                 // exception from the exception.)
                 // This is the dual to the special exception for offset-by-0
-                // in the inbounds pointer offset operation (see the Miri code, `src/operator.rs`).
+                // in the inbounds pointer offset operation (see `ptr_offset_inbounds` below).
-                //
+                match (self.memory.ptr_try_get_alloc(a), self.memory.ptr_try_get_alloc(b)) {
-                // Control flow is weird because we cannot early-return (to reach the
+                    (Err(a), Err(b)) if a == b && a != 0 => {
-                // `go_to_block` at the end).
+                        // Both are the same non-null integer.
-                let done = if let (Ok(a), Ok(b)) = (a.try_to_int(), b.try_to_int()) {
-                    let a = a.try_to_machine_usize(*self.tcx).unwrap();
-                    let b = b.try_to_machine_usize(*self.tcx).unwrap();
-                    if a == b && a != 0 {
                         self.write_scalar(Scalar::from_machine_isize(0, self), dest)?;
-                        true
-                    } else {
-                        false
                     }
-                } else {
+                    (Err(offset), _) | (_, Err(offset)) => {
-                    false
+                        throw_ub!(DanglingIntPointer(offset, CheckInAllocMsg::OffsetFromTest));
-                };
+                    }
+                    (Ok((a_alloc_id, a_offset, _)), Ok((b_alloc_id, b_offset, _))) => {
+                        // Both are pointers. They must be into the same allocation.
+                        if a_alloc_id != b_alloc_id {
+                            throw_ub_format!(
+                                "ptr_offset_from cannot compute offset of pointers into different \
+                                allocations.",
+                            );
+                        }
+                        // And they must both be valid for zero-sized accesses ("in-bounds or one past the end").
+                        self.memory.check_ptr_access_align(
+                            a,
+                            Size::ZERO,
+                            Align::ONE,
+                            CheckInAllocMsg::OffsetFromTest,
+                        )?;
+                        self.memory.check_ptr_access_align(
+                            b,
+                            Size::ZERO,
+                            Align::ONE,
+                            CheckInAllocMsg::OffsetFromTest,
+                        )?;
 
-                if !done {
+                        // Compute offset.
-                    // General case: we need two pointers.
+                        let usize_layout = self.layout_of(self.tcx.types.usize)?;
-                    let a = self.scalar_to_ptr(a);
+                        let isize_layout = self.layout_of(self.tcx.types.isize)?;
-                    let b = self.scalar_to_ptr(b);
+                        let a_offset = ImmTy::from_uint(a_offset.bytes(), usize_layout);
-                    let (a_alloc_id, a_offset, _) = self.memory.ptr_get_alloc(a)?;
+                        let b_offset = ImmTy::from_uint(b_offset.bytes(), usize_layout);
-                    let (b_alloc_id, b_offset, _) = self.memory.ptr_get_alloc(b)?;
+                        let (val, _overflowed, _ty) =
-                    if a_alloc_id != b_alloc_id {
+                            self.overflowing_binary_op(BinOp::Sub, &a_offset, &b_offset)?;
-                        throw_ub_format!(
+                        let pointee_layout = self.layout_of(substs.type_at(0))?;
-                            "ptr_offset_from cannot compute offset of pointers into different \
+                        let val = ImmTy::from_scalar(val, isize_layout);
-                            allocations.",
+                        let size = ImmTy::from_int(pointee_layout.size.bytes(), isize_layout);
-                        );
+                        self.exact_div(&val, &size, dest)?;
                     }
-                    let usize_layout = self.layout_of(self.tcx.types.usize)?;
-                    let isize_layout = self.layout_of(self.tcx.types.isize)?;
-                    let a_offset = ImmTy::from_uint(a_offset.bytes(), usize_layout);
-                    let b_offset = ImmTy::from_uint(b_offset.bytes(), usize_layout);
-                    let (val, _overflowed, _ty) =
-                        self.overflowing_binary_op(BinOp::Sub, &a_offset, &b_offset)?;
-                    let pointee_layout = self.layout_of(substs.type_at(0))?;
-                    let val = ImmTy::from_scalar(val, isize_layout);
-                    let size = ImmTy::from_int(pointee_layout.size.bytes(), isize_layout);
-                    self.exact_div(&val, &size, dest)?;
                 }
             }
 

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -388,9 +388,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
                 CheckInAllocMsg::DerefTest | CheckInAllocMsg::MemoryAccessTest => {
                     AllocCheck::Dereferenceable
                 }
-                CheckInAllocMsg::PointerArithmeticTest | CheckInAllocMsg::InboundsTest => {
+                CheckInAllocMsg::PointerArithmeticTest
-                    AllocCheck::Live
+                | CheckInAllocMsg::OffsetFromTest
-                }
+                | CheckInAllocMsg::InboundsTest => AllocCheck::Live,
             };
             let (size, align) = self.get_size_and_align(alloc_id, check)?;
             Ok((size, align, ()))

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -122,7 +122,7 @@ impl<'tt> TokenTreeOrTokenTreeSlice<'tt> {
 
 /// An unzipping of `TokenTree`s... see the `stack` field of `MatcherPos`.
 ///
-/// This is used by `inner_parse_loop` to keep track of delimited submatchers that we have
+/// This is used by `parse_tt_inner` to keep track of delimited submatchers that we have
 /// descended into.
 #[derive(Clone)]
 struct MatcherTtFrame<'tt> {
@@ -439,9 +439,8 @@ fn nameize<I: Iterator<Item = NamedMatch>>(
                 }
                 Occupied(..) => return Err((sp, format!("duplicated bind name: {}", bind_name))),
             },
-            // FIXME(c410-f3r) MetaVar and MetaVarExpr should be handled instead of being ignored
+            TokenTree::Token(..) => (),
-            // https://github.com/rust-lang/rust/issues/9390
+            TokenTree::MetaVar(..) | TokenTree::MetaVarExpr(..) => unreachable!(),
-            TokenTree::MetaVar(..) | TokenTree::MetaVarExpr(..) | TokenTree::Token(..) => {}
         }
 
         Ok(())
@@ -481,21 +480,24 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
 ///   successful execution of this function.
 /// - `next_items`: the set of newly generated items. These are used to replenish `cur_items` in
 ///   the function `parse`.
-/// - `eof_items`: the set of items that would be valid if this was the EOF.
 /// - `bb_items`: the set of items that are waiting for the black-box parser.
 /// - `token`: the current token of the parser.
 ///
 /// # Returns
 ///
-/// A `ParseResult`. Note that matches are kept track of through the items generated.
+/// `Some(result)` if everything is finished, `None` otherwise. Note that matches are kept track of
-fn inner_parse_loop<'root, 'tt>(
+/// through the items generated.
+fn parse_tt_inner<'root, 'tt>(
     sess: &ParseSess,
+    ms: &[TokenTree],
     cur_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
-    next_items: &mut Vec<MatcherPosHandle<'root, 'tt>>,
+    next_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
     bb_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
-    eof_items: &mut EofItems<'root, 'tt>,
     token: &Token,
-) -> Result<(), (rustc_span::Span, String)> {
+) -> Option<NamedParseResult> {
+    // Matcher positions that would be valid if the macro invocation was over now
+    let mut eof_items = EofItems::None;
+
     // Pop items from `cur_items` until it is empty.
     while let Some(mut item) = cur_items.pop() {
         // When unzipped trees end, remove them. This corresponds to backtracking out of a
@@ -522,6 +524,8 @@ fn inner_parse_loop<'root, 'tt>(
             // then we could be at the end of a sequence or at the beginning of the next
             // repetition.
             if let Some(repetition) = &item.repetition {
+                debug_assert!(matches!(item.top_elts, Tt(TokenTree::Sequence(..))));
+
                 // At this point, regardless of whether there is a separator, we should add all
                 // matches from the complete repetition of the sequence to the shared, top-level
                 // `matches` list (actually, `up.matches`, which could itself not be the top-level,
@@ -565,7 +569,7 @@ fn inner_parse_loop<'root, 'tt>(
             } else {
                 // If we are not in a repetition, then being at the end of a matcher means that we
                 // have reached the potential end of the input.
-                *eof_items = match eof_items {
+                eof_items = match eof_items {
                     EofItems::None => EofItems::One(item),
                     EofItems::One(_) | EofItems::Multiple => EofItems::Multiple,
                 }
@@ -613,7 +617,7 @@ fn inner_parse_loop<'root, 'tt>(
                 // We need to match a metavar (but the identifier is invalid)... this is an error
                 TokenTree::MetaVarDecl(span, _, None) => {
                     if sess.missing_fragment_specifiers.borrow_mut().remove(&span).is_some() {
-                        return Err((span, "missing fragment specifier".to_string()));
+                        return Some(Error(span, "missing fragment specifier".to_string()));
                     }
                 }
 
@@ -655,13 +659,36 @@ fn inner_parse_loop<'root, 'tt>(
                 // rules. NOTE that this is not necessarily an error unless _all_ items in
                 // `cur_items` end up doing this. There may still be some other matchers that do
                 // end up working out.
-                TokenTree::Token(..) | TokenTree::MetaVar(..) | TokenTree::MetaVarExpr(..) => {}
+                TokenTree::Token(..) => {}
+
+                TokenTree::MetaVar(..) | TokenTree::MetaVarExpr(..) => unreachable!(),
             }
         }
     }
 
-    // Yay a successful parse (so far)!
+    // If we reached the EOF, check that there is EXACTLY ONE possible matcher. Otherwise,
-    Ok(())
+    // either the parse is ambiguous (which should never happen) or there is a syntax error.
+    if *token == token::Eof {
+        Some(match eof_items {
+            EofItems::One(mut eof_item) => {
+                let matches =
+                    eof_item.matches.iter_mut().map(|dv| Lrc::make_mut(dv).pop().unwrap());
+                nameize(sess, ms, matches)
+            }
+            EofItems::Multiple => {
+                Error(token.span, "ambiguity: multiple successful parses".to_string())
+            }
+            EofItems::None => Failure(
+                Token::new(
+                    token::Eof,
+                    if token.span.is_dummy() { token.span } else { token.span.shrink_to_hi() },
+                ),
+                "missing tokens in macro arguments",
+            ),
+        })
+    } else {
+        None
+    }
 }
 
 /// Use the given sequence of token trees (`ms`) as a matcher. Match the token
@@ -672,7 +699,7 @@ pub(super) fn parse_tt(
     macro_name: Ident,
 ) -> NamedParseResult {
     // A queue of possible matcher positions. We initialize it with the matcher position in which
-    // the "dot" is before the first token of the first token tree in `ms`. `inner_parse_loop` then
+    // the "dot" is before the first token of the first token tree in `ms`. `parse_tt_inner` then
     // processes all of these possible matcher positions and produces possible next positions into
     // `next_items`. After some post-processing, the contents of `next_items` replenish `cur_items`
     // and we start over again.
@@ -681,135 +708,118 @@ pub(super) fn parse_tt(
     // there are frequently *no* others! -- are allocated on the heap.
     let mut initial = MatcherPos::new(ms);
     let mut cur_items = smallvec![MatcherPosHandle::Ref(&mut initial)];
-    let mut next_items = Vec::new();
 
     loop {
-        assert!(next_items.is_empty());
+        let mut next_items = SmallVec::new();
 
         // Matcher positions black-box parsed by parser.rs (`parser`)
         let mut bb_items = SmallVec::new();
 
-        // Matcher positions that would be valid if the macro invocation was over now
-        let mut eof_items = EofItems::None;
-
         // Process `cur_items` until either we have finished the input or we need to get some
         // parsing from the black-box parser done. The result is that `next_items` will contain a
         // bunch of possible next matcher positions in `next_items`.
-        match inner_parse_loop(
+        if let Some(result) = parse_tt_inner(
             parser.sess,
+            ms,
             &mut cur_items,
             &mut next_items,
             &mut bb_items,
-            &mut eof_items,
             &parser.token,
         ) {
-            Ok(()) => {}
+            return result;
-            Err((sp, msg)) => return Error(sp, msg),
         }
 
-        // inner parse loop handled all cur_items, so it's empty
+        // `parse_tt_inner` handled all cur_items, so it's empty.
         assert!(cur_items.is_empty());
 
-        // We need to do some post processing after the `inner_parse_loop`.
+        // We need to do some post processing after the `parse_tt_inner`.
         //
         // Error messages here could be improved with links to original rules.
 
-        // If we reached the EOF, check that there is EXACTLY ONE possible matcher. Otherwise,
+        match (next_items.len(), bb_items.len()) {
-        // either the parse is ambiguous (which should never happen) or there is a syntax error.
+            (0, 0) => {
-        if parser.token == token::Eof {
+                // There are no possible next positions AND we aren't waiting for the black-box
-            return match eof_items {
+                // parser: syntax error.
-                EofItems::One(mut eof_item) => {
+                return Failure(parser.token.clone(), "no rules expected this token in macro call");
-                    let matches =
+            }
-                        eof_item.matches.iter_mut().map(|dv| Lrc::make_mut(dv).pop().unwrap());
+
-                    nameize(parser.sess, ms, matches)
+            (_, 0) => {
-                }
+                // Dump all possible `next_items` into `cur_items` for the next iteration. Then
-                EofItems::Multiple => {
+                // process the next token.
-                    Error(parser.token.span, "ambiguity: multiple successful parses".to_string())
+                cur_items.extend(next_items.drain(..));
-                }
+                parser.to_mut().bump();
-                EofItems::None => Failure(
+            }
-                    Token::new(
+
-                        token::Eof,
+            (0, 1) => {
-                        if parser.token.span.is_dummy() {
+                // We need to call the black-box parser to get some nonterminal.
-                            parser.token.span
+                let mut item = bb_items.pop().unwrap();
-                        } else {
+                if let TokenTree::MetaVarDecl(span, _, Some(kind)) = item.top_elts.get_tt(item.idx)
-                            parser.token.span.shrink_to_hi()
+                {
-                        },
+                    let match_cur = item.match_cur;
-                    ),
+                    // We use the span of the metavariable declaration to determine any
-                    "missing tokens in macro arguments",
+                    // edition-specific matching behavior for non-terminals.
-                ),
+                    let nt = match parser.to_mut().parse_nonterminal(kind) {
-            };
+                        Err(mut err) => {
-        }
+                            err.span_label(
-        // Performance hack: `eof_items` may share matchers via `Rc` with other things that we want
+                                span,
-        // to modify. Dropping `eof_items` now may drop these refcounts to 1, preventing an
+                                format!("while parsing argument for this `{kind}` macro fragment"),
-        // unnecessary implicit clone later in `Rc::make_mut`.
+                            )
-        drop(eof_items);
+                            .emit();
-
+                            return ErrorReported;
-        // If there are no possible next positions AND we aren't waiting for the black-box parser,
+                        }
-        // then there is a syntax error.
+                        Ok(nt) => nt,
-        if bb_items.is_empty() && next_items.is_empty() {
+                    };
-            return Failure(parser.token.clone(), "no rules expected this token in macro call");
+                    item.push_match(match_cur, MatchedNonterminal(Lrc::new(nt)));
-        }
+                    item.idx += 1;
-
+                    item.match_cur += 1;
-        if (!bb_items.is_empty() && !next_items.is_empty()) || bb_items.len() > 1 {
+                } else {
-            // We need to call out to parse some rust nonterminal (black-box) parser. But something
+                    unreachable!()
-            // is wrong, because there is not EXACTLY ONE of these.
+                }
-            let nts = bb_items
+                cur_items.push(item);
-                .iter()
+            }
-                .map(|item| match item.top_elts.get_tt(item.idx) {
+
-                    TokenTree::MetaVarDecl(_, bind, Some(kind)) => format!("{} ('{}')", kind, bind),
+            (_, _) => {
-                    _ => panic!(),
+                // We need to call the black-box parser to get some nonterminal, but something is
-                })
+                // wrong.
-                .collect::<Vec<String>>()
+                return bb_items_ambiguity_error(
-                .join(" or ");
+                    macro_name,
-
+                    next_items,
-            return Error(
+                    bb_items,
-                parser.token.span,
+                    parser.token.span,
-                format!(
+                );
-                    "local ambiguity when calling macro `{macro_name}`: multiple parsing options: {}",
-                    match next_items.len() {
-                        0 => format!("built-in NTs {}.", nts),
-                        1 => format!("built-in NTs {} or 1 other option.", nts),
-                        n => format!("built-in NTs {} or {} other options.", nts, n),
-                    }
-                ),
-            );
-        }
-
-        if !next_items.is_empty() {
-            // Dump all possible `next_items` into `cur_items` for the next iteration. Then process
-            // the next token.
-            cur_items.extend(next_items.drain(..));
-            parser.to_mut().bump();
-        } else {
-            // Finally, we have the case where we need to call the black-box parser to get some
-            // nonterminal.
-            assert_eq!(bb_items.len(), 1);
-
-            let mut item = bb_items.pop().unwrap();
-            if let TokenTree::MetaVarDecl(span, _, Some(kind)) = item.top_elts.get_tt(item.idx) {
-                let match_cur = item.match_cur;
-                // We use the span of the metavariable declaration to determine any
-                // edition-specific matching behavior for non-terminals.
-                let nt = match parser.to_mut().parse_nonterminal(kind) {
-                    Err(mut err) => {
-                        err.span_label(
-                            span,
-                            format!("while parsing argument for this `{}` macro fragment", kind),
-                        )
-                        .emit();
-                        return ErrorReported;
-                    }
-                    Ok(nt) => nt,
-                };
-                item.push_match(match_cur, MatchedNonterminal(Lrc::new(nt)));
-                item.idx += 1;
-                item.match_cur += 1;
-            } else {
-                unreachable!()
             }
-            cur_items.push(item);
         }
 
         assert!(!cur_items.is_empty());
     }
 }
+
+fn bb_items_ambiguity_error<'root, 'tt>(
+    macro_name: Ident,
+    next_items: SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
+    bb_items: SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
+    token_span: rustc_span::Span,
+) -> NamedParseResult {
+    let nts = bb_items
+        .iter()
+        .map(|item| match item.top_elts.get_tt(item.idx) {
+            TokenTree::MetaVarDecl(_, bind, Some(kind)) => {
+                format!("{} ('{}')", kind, bind)
+            }
+            _ => panic!(),
+        })
+        .collect::<Vec<String>>()
+        .join(" or ");
+
+    Error(
+        token_span,
+        format!(
+            "local ambiguity when calling macro `{macro_name}`: multiple parsing options: {}",
+            match next_items.len() {
+                0 => format!("built-in NTs {}.", nts),
+                1 => format!("built-in NTs {} or 1 other option.", nts),
+                n => format!("built-in NTs {} or {} other options.", nts, n),
+            }
+        ),
+    )
+}

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -184,6 +184,8 @@ pub enum CheckInAllocMsg {
     MemoryAccessTest,
     /// We are doing pointer arithmetic.
     PointerArithmeticTest,
+    /// We are doing pointer offset_from.
+    OffsetFromTest,
     /// None of the above -- generic/unspecific inbounds test.
     InboundsTest,
 }
@@ -199,6 +201,7 @@ impl fmt::Display for CheckInAllocMsg {
                 CheckInAllocMsg::DerefTest => "dereferencing pointer failed: ",
                 CheckInAllocMsg::MemoryAccessTest => "memory access failed: ",
                 CheckInAllocMsg::PointerArithmeticTest => "pointer arithmetic failed: ",
+                CheckInAllocMsg::OffsetFromTest => "out-of-bounds offset_from: ",
                 CheckInAllocMsg::InboundsTest => "",
             }
         )
@@ -358,6 +361,9 @@ impl fmt::Display for UndefinedBehaviorInfo<'_> {
             DanglingIntPointer(0, CheckInAllocMsg::InboundsTest) => {
                 write!(f, "null pointer is not a valid pointer for this operation")
             }
+            DanglingIntPointer(0, msg) => {
+                write!(f, "{}null pointer is not a valid pointer", msg)
+            }
             DanglingIntPointer(i, msg) => {
                 write!(f, "{}0x{:x} is not a valid pointer", msg, i)
             }

compiler/rustc_parse/src/parser/item.rs

@@ -1534,6 +1534,16 @@ impl<'a> Parser<'a> {
         let name = self.parse_field_ident(adt_ty, lo)?;
         self.expect_field_ty_separator()?;
         let ty = self.parse_ty()?;
+        if self.token.kind == token::Colon && self.look_ahead(1, |tok| tok.kind != token::Colon) {
+            self.struct_span_err(self.token.span, "found single colon in a struct field type path")
+                .span_suggestion_verbose(
+                    self.token.span,
+                    "write a path separator here",
+                    "::".to_string(),
+                    Applicability::MaybeIncorrect,
+                )
+                .emit();
+        }
         if self.token.kind == token::Eq {
             self.bump();
             let const_expr = self.parse_anon_const_expr()?;

library/core/src/char/convert.rs

@@ -218,6 +218,8 @@ impl const From<u8> for char {
 }
 
 /// An error which can be returned when parsing a char.
+///
+/// This `struct` is created when using the [`char::from_str`] method.
 #[stable(feature = "char_from_str", since = "1.20.0")]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct ParseCharError {
@@ -300,7 +302,10 @@ impl TryFrom<u32> for char {
     }
 }
 
-/// The error type returned when a conversion from u32 to char fails.
+/// The error type returned when a conversion from [`prim@u32`] to [`prim@char`] fails.
+///
+/// This `struct` is created by the [`char::try_from<u32>`](char#impl-TryFrom<u32>) method.
+/// See its documentation for more.
 #[stable(feature = "try_from", since = "1.34.0")]
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub struct CharTryFromError(());

library/core/src/future/into_future.rs

@@ -9,20 +9,20 @@ pub trait IntoFuture {
 
     /// Which kind of future are we turning this into?
     #[unstable(feature = "into_future", issue = "67644")]
-    type Future: Future<Output = Self::Output>;
+    type IntoFuture: Future<Output = Self::Output>;
 
     /// Creates a future from a value.
     #[unstable(feature = "into_future", issue = "67644")]
     #[lang = "into_future"]
-    fn into_future(self) -> Self::Future;
+    fn into_future(self) -> Self::IntoFuture;
 }
 
 #[unstable(feature = "into_future", issue = "67644")]
 impl<F: Future> IntoFuture for F {
     type Output = F::Output;
-    type Future = F;
+    type IntoFuture = F;
 
-    fn into_future(self) -> Self::Future {
+    fn into_future(self) -> Self::IntoFuture {
         self
     }
 }

library/core/src/num/dec2flt/mod.rs

@@ -112,21 +112,24 @@ macro_rules! from_str_float_impl {
             /// * '2.5E-10'
             /// * '5.'
             /// * '.5', or, equivalently, '0.5'
-            /// * 'inf', '-inf', 'NaN'
+            /// * 'inf', '-inf', '+infinity', 'NaN'
+            ///
+            /// Note that alphabetical characters are not case-sensitive.
             ///
             /// Leading and trailing whitespace represent an error.
             ///
             /// # Grammar
             ///
-            /// All strings that adhere to the following [EBNF] grammar
+            /// All strings that adhere to the following [EBNF] grammar when
-            /// will result in an [`Ok`] being returned:
+            /// lowercased will result in an [`Ok`] being returned:
             ///
             /// ```txt
-            /// Float  ::= Sign? ( 'inf' | 'NaN' | Number )
+            /// Float  ::= Sign? ( 'inf' | 'infinity' | 'nan' | Number )
             /// Number ::= ( Digit+ |
+            ///              '.' Digit* |
             ///              Digit+ '.' Digit* |
             ///              Digit* '.' Digit+ ) Exp?
-            /// Exp    ::= [eE] Sign? Digit+
+            /// Exp    ::= 'e' Sign? Digit+
             /// Sign   ::= [+-]
             /// Digit  ::= [0-9]
             /// ```

src/librustdoc/html/render/mod.rs

@@ -699,7 +699,13 @@ fn short_item_info(
 
 // Render the list of items inside one of the sections "Trait Implementations",
 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
-fn render_impls(cx: &Context<'_>, w: &mut Buffer, impls: &[&&Impl], containing_item: &clean::Item) {
+fn render_impls(
+    cx: &Context<'_>,
+    w: &mut Buffer,
+    impls: &[&&Impl],
+    containing_item: &clean::Item,
+    toggle_open_by_default: bool,
+) {
     let tcx = cx.tcx();
     let mut rendered_impls = impls
         .iter()
@@ -722,7 +728,7 @@ fn render_impls(cx: &Context<'_>, w: &mut Buffer, impls: &[&&Impl], containing_i
                     is_on_foreign_type: false,
                     show_default_items: true,
                     show_non_assoc_items: true,
-                    toggle_open_by_default: true,
+                    toggle_open_by_default,
                 },
             );
             buffer.into_inner()
@@ -1143,7 +1149,7 @@ fn render_assoc_items_inner(
             concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
 
         let mut impls = Buffer::empty_from(w);
-        render_impls(cx, &mut impls, &concrete, containing_item);
+        render_impls(cx, &mut impls, &concrete, containing_item, true);
         let impls = impls.into_inner();
         if !impls.is_empty() {
             write!(
@@ -1165,7 +1171,7 @@ fn render_assoc_items_inner(
                  </h2>\
                  <div id=\"synthetic-implementations-list\">",
             );
-            render_impls(cx, w, &synthetic, containing_item);
+            render_impls(cx, w, &synthetic, containing_item, false);
             w.write_str("</div>");
         }
 
@@ -1177,7 +1183,7 @@ fn render_assoc_items_inner(
                  </h2>\
                  <div id=\"blanket-implementations-list\">",
             );
-            render_impls(cx, w, &blanket_impl, containing_item);
+            render_impls(cx, w, &blanket_impl, containing_item, false);
             w.write_str("</div>");
         }
     }

src/test/rustdoc-gui/toggle-docs.goml

@@ -17,7 +17,14 @@ assert-text: ("#toggle-all-docs", "[−]")
 goto: file://|DOC_PATH|/test_docs/struct.Foo.html
 // We first check that everything is visible.
 assert-text: ("#toggle-all-docs", "[−]")
-assert-attribute: ("details.rustdoc-toggle", {"open": ""}, ALL)
+assert-attribute: ("#implementations-list details.rustdoc-toggle", {"open": ""}, ALL)
+assert-attribute: ("#trait-implementations-list details.rustdoc-toggle", {"open": ""}, ALL)
+assert-attribute-false: (
+    "#blanket-implementations-list > details.rustdoc-toggle",
+    {"open": ""},
+    ALL,
+)
+
 // We collapse them all.
 click: "#toggle-all-docs"
 wait-for: 50

src/test/ui/async-await/await-into-future.rs

@@ -10,9 +10,9 @@ struct AwaitMe;
 
 impl IntoFuture for AwaitMe {
     type Output = i32;
-    type Future = Pin<Box<dyn Future<Output = i32>>>;
+    type IntoFuture = Pin<Box<dyn Future<Output = i32>>>;
 
-    fn into_future(self) -> Self::Future {
+    fn into_future(self) -> Self::IntoFuture {
         Box::pin(me())
     }
 }

src/test/ui/consts/offset_from_ub.rs

@@ -1,4 +1,4 @@
-#![feature(const_ptr_offset_from)]
+#![feature(const_ptr_offset_from, const_ptr_offset)]
 #![feature(core_intrinsics)]
 
 use std::intrinsics::ptr_offset_from;
@@ -44,4 +44,30 @@ pub const DIFFERENT_INT: isize = { // offset_from with two different integers: l
     //~| 0x10 is not a valid pointer
 };
 
+const OUT_OF_BOUNDS_1: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    // First ptr is out of bounds
+    unsafe { ptr_offset_from(end_ptr, start_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer at offset 10 is out-of-bounds
+};
+
+const OUT_OF_BOUNDS_2: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    // Second ptr is out of bounds
+    unsafe { ptr_offset_from(start_ptr, end_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer at offset 10 is out-of-bounds
+};
+
+const OUT_OF_BOUNDS_SAME: isize = {
+    let start_ptr = &4 as *const _ as *const u8;
+    let length = 10;
+    let end_ptr = (start_ptr).wrapping_add(length);
+    unsafe { ptr_offset_from(end_ptr, end_ptr) } //~ERROR evaluation of constant value failed
+    //~| pointer at offset 10 is out-of-bounds
+};
+
 fn main() {}

src/test/ui/consts/offset_from_ub.stderr

@@ -10,7 +10,7 @@ error[E0080]: evaluation of constant value failed
 LL |         unsafe { intrinsics::ptr_offset_from(self, origin) }
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |                  |
-   |                  0x2a is not a valid pointer
+   |                  out-of-bounds offset_from: 0x2a is not a valid pointer
    |                  inside `ptr::const_ptr::<impl *const u8>::offset_from` at $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
    |
   ::: $DIR/offset_from_ub.rs:23:14
@@ -28,14 +28,32 @@ error[E0080]: evaluation of constant value failed
   --> $DIR/offset_from_ub.rs:36:14
    |
 LL |     unsafe { ptr_offset_from(ptr, ptr) }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^ null pointer is not a valid pointer for this operation
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds offset_from: null pointer is not a valid pointer
 
 error[E0080]: evaluation of constant value failed
   --> $DIR/offset_from_ub.rs:43:14
    |
 LL |     unsafe { ptr_offset_from(ptr2, ptr1) }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0x10 is not a valid pointer
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds offset_from: 0x10 is not a valid pointer
 
-error: aborting due to 5 previous errors
+error[E0080]: evaluation of constant value failed
+  --> $DIR/offset_from_ub.rs:52:14
+   |
+LL |     unsafe { ptr_offset_from(end_ptr, start_ptr) }
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds offset_from: alloc18 has size 4, so pointer at offset 10 is out-of-bounds
+
+error[E0080]: evaluation of constant value failed
+  --> $DIR/offset_from_ub.rs:61:14
+   |
+LL |     unsafe { ptr_offset_from(start_ptr, end_ptr) }
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds offset_from: alloc21 has size 4, so pointer at offset 10 is out-of-bounds
+
+error[E0080]: evaluation of constant value failed
+  --> $DIR/offset_from_ub.rs:69:14
+   |
+LL |     unsafe { ptr_offset_from(end_ptr, end_ptr) }
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds offset_from: alloc24 has size 4, so pointer at offset 10 is out-of-bounds
+
+error: aborting due to 8 previous errors
 
 For more information about this error, try `rustc --explain E0080`.

src/test/ui/consts/offset_ub.stderr

@@ -144,7 +144,7 @@ error[E0080]: evaluation of constant value failed
 LL |         unsafe { intrinsics::offset(self, count) }
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |                  |
-   |                  pointer arithmetic failed: 0x0 is not a valid pointer
+   |                  pointer arithmetic failed: null pointer is not a valid pointer
    |                  inside `ptr::const_ptr::<impl *const u8>::offset` at $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
    |
   ::: $DIR/offset_ub.rs:22:50

src/test/ui/suggestions/struct-field-type-including-single-colon.rs

@@ -0,0 +1,20 @@
+mod foo {
+    struct A;
+    mod bar {
+        struct B;
+    }
+}
+
+struct Foo {
+    a: foo:A,
+    //~^ ERROR found single colon in a struct field type path
+    //~| expected `,`, or `}`, found `:`
+}
+
+struct Bar {
+    b: foo::bar:B,
+    //~^ ERROR found single colon in a struct field type path
+    //~| expected `,`, or `}`, found `:`
+}
+
+fn main() {}

src/test/ui/suggestions/struct-field-type-including-single-colon.stderr

@@ -0,0 +1,36 @@
+error: found single colon in a struct field type path
+  --> $DIR/struct-field-type-including-single-colon.rs:9:11
+   |
+LL |     a: foo:A,
+   |           ^
+   |
+help: write a path separator here
+   |
+LL |     a: foo::A,
+   |           ~~
+
+error: expected `,`, or `}`, found `:`
+  --> $DIR/struct-field-type-including-single-colon.rs:9:11
+   |
+LL |     a: foo:A,
+   |           ^
+
+error: found single colon in a struct field type path
+  --> $DIR/struct-field-type-including-single-colon.rs:15:16
+   |
+LL |     b: foo::bar:B,
+   |                ^
+   |
+help: write a path separator here
+   |
+LL |     b: foo::bar::B,
+   |                ~~
+
+error: expected `,`, or `}`, found `:`
+  --> $DIR/struct-field-type-including-single-colon.rs:15:16
+   |
+LL |     b: foo::bar:B,
+   |                ^
+
+error: aborting due to 4 previous errors
+