Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 957 insertions, 0 deletions

diff --git a/rust/syn/pat.rs b/rust/syn/pat.rs
new file mode 100644
index 000000000..46edd63d5
--- /dev/null
+++ b/rust/syn/pat.rs
@@ -0,0 +1,957 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use crate::attr::Attribute;
+use crate::expr::Member;
+use crate::ident::Ident;
+use crate::path::{Path, QSelf};
+use crate::punctuated::Punctuated;
+use crate::token;
+use crate::ty::Type;
+use proc_macro2::TokenStream;
+
+pub use crate::expr::{
+    ExprConst as PatConst, ExprLit as PatLit, ExprMacro as PatMacro, ExprPath as PatPath,
+    ExprRange as PatRange,
+};
+
+ast_enum_of_structs! {
+    /// A pattern in a local binding, function signature, match expression, or
+    /// various other places.
+    ///
+    /// # Syntax tree enum
+    ///
+    /// This type is a [syntax tree enum].
+    ///
+    /// [syntax tree enum]: crate::expr::Expr#syntax-tree-enums
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    #[non_exhaustive]
+    pub enum Pat {
+        /// A const block: `const { ... }`.
+        Const(PatConst),
+
+        /// A pattern that binds a new variable: `ref mut binding @ SUBPATTERN`.
+        Ident(PatIdent),
+
+        /// A literal pattern: `0`.
+        Lit(PatLit),
+
+        /// A macro in pattern position.
+        Macro(PatMacro),
+
+        /// A pattern that matches any one of a set of cases.
+        Or(PatOr),
+
+        /// A parenthesized pattern: `(A | B)`.
+        Paren(PatParen),
+
+        /// A path pattern like `Color::Red`, optionally qualified with a
+        /// self-type.
+        ///
+        /// Unqualified path patterns can legally refer to variants, structs,
+        /// constants or associated constants. Qualified path patterns like
+        /// `<A>::B::C` and `<A as Trait>::B::C` can only legally refer to
+        /// associated constants.
+        Path(PatPath),
+
+        /// A range pattern: `1..=2`.
+        Range(PatRange),
+
+        /// A reference pattern: `&mut var`.
+        Reference(PatReference),
+
+        /// The dots in a tuple or slice pattern: `[0, 1, ..]`.
+        Rest(PatRest),
+
+        /// A dynamically sized slice pattern: `[a, b, ref i @ .., y, z]`.
+        Slice(PatSlice),
+
+        /// A struct or struct variant pattern: `Variant { x, y, .. }`.
+        Struct(PatStruct),
+
+        /// A tuple pattern: `(a, b)`.
+        Tuple(PatTuple),
+
+        /// A tuple struct or tuple variant pattern: `Variant(x, y, .., z)`.
+        TupleStruct(PatTupleStruct),
+
+        /// A type ascription pattern: `foo: f64`.
+        Type(PatType),
+
+        /// Tokens in pattern position not interpreted by Syn.
+        Verbatim(TokenStream),
+
+        /// A pattern that matches any value: `_`.
+        Wild(PatWild),
+
+        // For testing exhaustiveness in downstream code, use the following idiom:
+        //
+        //     match pat {
+        //         #![cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+        //
+        //         Pat::Box(pat) => {...}
+        //         Pat::Ident(pat) => {...}
+        //         ...
+        //         Pat::Wild(pat) => {...}
+        //
+        //         _ => { /* some sane fallback */ }
+        //     }
+        //
+        // This way we fail your tests but don't break your library when adding
+        // a variant. You will be notified by a test failure when a variant is
+        // added, so that you can add code to handle it, but your library will
+        // continue to compile and work for downstream users in the interim.
+    }
+}
+
+ast_struct! {
+    /// A pattern that binds a new variable: `ref mut binding @ SUBPATTERN`.
+    ///
+    /// It may also be a unit struct or struct variant (e.g. `None`), or a
+    /// constant; these cannot be distinguished syntactically.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatIdent {
+        pub attrs: Vec<Attribute>,
+        pub by_ref: Option<Token![ref]>,
+        pub mutability: Option<Token![mut]>,
+        pub ident: Ident,
+        pub subpat: Option<(Token![@], Box<Pat>)>,
+    }
+}
+
+ast_struct! {
+    /// A pattern that matches any one of a set of cases.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatOr {
+        pub attrs: Vec<Attribute>,
+        pub leading_vert: Option<Token![|]>,
+        pub cases: Punctuated<Pat, Token![|]>,
+    }
+}
+
+ast_struct! {
+    /// A parenthesized pattern: `(A | B)`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatParen {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub pat: Box<Pat>,
+    }
+}
+
+ast_struct! {
+    /// A reference pattern: `&mut var`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatReference {
+        pub attrs: Vec<Attribute>,
+        pub and_token: Token![&],
+        pub mutability: Option<Token![mut]>,
+        pub pat: Box<Pat>,
+    }
+}
+
+ast_struct! {
+    /// The dots in a tuple or slice pattern: `[0, 1, ..]`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatRest {
+        pub attrs: Vec<Attribute>,
+        pub dot2_token: Token![..],
+    }
+}
+
+ast_struct! {
+    /// A dynamically sized slice pattern: `[a, b, ref i @ .., y, z]`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatSlice {
+        pub attrs: Vec<Attribute>,
+        pub bracket_token: token::Bracket,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A struct or struct variant pattern: `Variant { x, y, .. }`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatStruct {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+        pub brace_token: token::Brace,
+        pub fields: Punctuated<FieldPat, Token![,]>,
+        pub rest: Option<PatRest>,
+    }
+}
+
+ast_struct! {
+    /// A tuple pattern: `(a, b)`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatTuple {
+        pub attrs: Vec<Attribute>,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A tuple struct or tuple variant pattern: `Variant(x, y, .., z)`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatTupleStruct {
+        pub attrs: Vec<Attribute>,
+        pub qself: Option<QSelf>,
+        pub path: Path,
+        pub paren_token: token::Paren,
+        pub elems: Punctuated<Pat, Token![,]>,
+    }
+}
+
+ast_struct! {
+    /// A type ascription pattern: `foo: f64`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatType {
+        pub attrs: Vec<Attribute>,
+        pub pat: Box<Pat>,
+        pub colon_token: Token![:],
+        pub ty: Box<Type>,
+    }
+}
+
+ast_struct! {
+    /// A pattern that matches any value: `_`.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct PatWild {
+        pub attrs: Vec<Attribute>,
+        pub underscore_token: Token![_],
+    }
+}
+
+ast_struct! {
+    /// A single field in a struct pattern.
+    ///
+    /// Patterns like the fields of Foo `{ x, ref y, ref mut z }` are treated
+    /// the same as `x: x, y: ref y, z: ref mut z` but there is no colon token.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct FieldPat {
+        pub attrs: Vec<Attribute>,
+        pub member: Member,
+        pub colon_token: Option<Token![:]>,
+        pub pat: Box<Pat>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use crate::attr::Attribute;
+    use crate::error::{self, Result};
+    use crate::expr::{
+        Expr, ExprConst, ExprLit, ExprMacro, ExprPath, ExprRange, Member, RangeLimits,
+    };
+    use crate::ext::IdentExt as _;
+    use crate::ident::Ident;
+    use crate::lit::Lit;
+    use crate::mac::{self, Macro};
+    use crate::parse::{Parse, ParseBuffer, ParseStream};
+    use crate::pat::{
+        FieldPat, Pat, PatIdent, PatOr, PatParen, PatReference, PatRest, PatSlice, PatStruct,
+        PatTuple, PatTupleStruct, PatType, PatWild,
+    };
+    use crate::path::{self, Path, QSelf};
+    use crate::punctuated::Punctuated;
+    use crate::stmt::Block;
+    use crate::token;
+    use crate::verbatim;
+    use proc_macro2::TokenStream;
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Pat {
+        /// Parse a pattern that does _not_ involve `|` at the top level.
+        ///
+        /// This parser matches the behavior of the `$:pat_param` macro_rules
+        /// matcher, and on editions prior to Rust 2021, the behavior of
+        /// `$:pat`.
+        ///
+        /// In Rust syntax, some examples of where this syntax would occur are
+        /// in the argument pattern of functions and closures. Patterns using
+        /// `|` are not allowed to occur in these positions.
+        ///
+        /// ```compile_fail
+        /// fn f(Some(_) | None: Option<T>) {
+        ///     let _ = |Some(_) | None: Option<T>| {};
+        ///     //       ^^^^^^^^^^^^^^^^^^^^^^^^^??? :(
+        /// }
+        /// ```
+        ///
+        /// ```console
+        /// error: top-level or-patterns are not allowed in function parameters
+        ///  --> src/main.rs:1:6
+        ///   |
+        /// 1 | fn f(Some(_) | None: Option<T>) {
+        ///   |      ^^^^^^^^^^^^^^ help: wrap the pattern in parentheses: `(Some(_) | None)`
+        /// ```
+        pub fn parse_single(input: ParseStream) -> Result<Self> {
+            let begin = input.fork();
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Ident)
+                && (input.peek2(Token![::])
+                    || input.peek2(Token![!])
+                    || input.peek2(token::Brace)
+                    || input.peek2(token::Paren)
+                    || input.peek2(Token![..]))
+                || input.peek(Token![self]) && input.peek2(Token![::])
+                || lookahead.peek(Token![::])
+                || lookahead.peek(Token![<])
+                || input.peek(Token![Self])
+                || input.peek(Token![super])
+                || input.peek(Token![crate])
+            {
+                pat_path_or_macro_or_struct_or_range(input)
+            } else if lookahead.peek(Token![_]) {
+                input.call(pat_wild).map(Pat::Wild)
+            } else if input.peek(Token![box]) {
+                pat_box(begin, input)
+            } else if input.peek(Token![-]) || lookahead.peek(Lit) || lookahead.peek(Token![const])
+            {
+                pat_lit_or_range(input)
+            } else if lookahead.peek(Token![ref])
+                || lookahead.peek(Token![mut])
+                || input.peek(Token![self])
+                || input.peek(Ident)
+            {
+                input.call(pat_ident).map(Pat::Ident)
+            } else if lookahead.peek(Token![&]) {
+                input.call(pat_reference).map(Pat::Reference)
+            } else if lookahead.peek(token::Paren) {
+                input.call(pat_paren_or_tuple)
+            } else if lookahead.peek(token::Bracket) {
+                input.call(pat_slice).map(Pat::Slice)
+            } else if lookahead.peek(Token![..]) && !input.peek(Token![...]) {
+                pat_range_half_open(input)
+            } else if lookahead.peek(Token![const]) {
+                input.call(pat_const).map(Pat::Verbatim)
+            } else {
+                Err(lookahead.error())
+            }
+        }
+
+        /// Parse a pattern, possibly involving `|`, but not a leading `|`.
+        pub fn parse_multi(input: ParseStream) -> Result<Self> {
+            multi_pat_impl(input, None)
+        }
+
+        /// Parse a pattern, possibly involving `|`, possibly including a
+        /// leading `|`.
+        ///
+        /// This parser matches the behavior of the Rust 2021 edition's `$:pat`
+        /// macro_rules matcher.
+        ///
+        /// In Rust syntax, an example of where this syntax would occur is in
+        /// the pattern of a `match` arm, where the language permits an optional
+        /// leading `|`, although it is not idiomatic to write one there in
+        /// handwritten code.
+        ///
+        /// ```
+        /// # let wat = None;
+        /// match wat {
+        ///     | None | Some(false) => {}
+        ///     | Some(true) => {}
+        /// }
+        /// ```
+        ///
+        /// The compiler accepts it only to facilitate some situations in
+        /// macro-generated code where a macro author might need to write:
+        ///
+        /// ```
+        /// # macro_rules! doc {
+        /// #     ($value:expr, ($($conditions1:pat),*), ($($conditions2:pat),*), $then:expr) => {
+        /// match $value {
+        ///     $(| $conditions1)* $(| $conditions2)* => $then
+        /// }
+        /// #     };
+        /// # }
+        /// #
+        /// # doc!(true, (true), (false), {});
+        /// # doc!(true, (), (true, false), {});
+        /// # doc!(true, (true, false), (), {});
+        /// ```
+        ///
+        /// Expressing the same thing correctly in the case that either one (but
+        /// not both) of `$conditions1` and `$conditions2` might be empty,
+        /// without leading `|`, is complex.
+        ///
+        /// Use [`Pat::parse_multi`] instead if you are not intending to support
+        /// macro-generated macro input.
+        pub fn parse_multi_with_leading_vert(input: ParseStream) -> Result<Self> {
+            let leading_vert: Option<Token![|]> = input.parse()?;
+            multi_pat_impl(input, leading_vert)
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for PatType {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(PatType {
+                attrs: Vec::new(),
+                pat: Box::new(Pat::parse_single(input)?),
+                colon_token: input.parse()?,
+                ty: input.parse()?,
+            })
+        }
+    }
+
+    fn multi_pat_impl(input: ParseStream, leading_vert: Option<Token![|]>) -> Result<Pat> {
+        let mut pat = Pat::parse_single(input)?;
+        if leading_vert.is_some()
+            || input.peek(Token![|]) && !input.peek(Token![||]) && !input.peek(Token![|=])
+        {
+            let mut cases = Punctuated::new();
+            cases.push_value(pat);
+            while input.peek(Token![|]) && !input.peek(Token![||]) && !input.peek(Token![|=]) {
+                let punct = input.parse()?;
+                cases.push_punct(punct);
+                let pat = Pat::parse_single(input)?;
+                cases.push_value(pat);
+            }
+            pat = Pat::Or(PatOr {
+                attrs: Vec::new(),
+                leading_vert,
+                cases,
+            });
+        }
+        Ok(pat)
+    }
+
+    fn pat_path_or_macro_or_struct_or_range(input: ParseStream) -> Result<Pat> {
+        let expr_style = true;
+        let (qself, path) = path::parsing::qpath(input, expr_style)?;
+
+        if qself.is_none()
+            && input.peek(Token![!])
+            && !input.peek(Token![!=])
+            && path.is_mod_style()
+        {
+            let bang_token: Token![!] = input.parse()?;
+            let (delimiter, tokens) = mac::parse_delimiter(input)?;
+            return Ok(Pat::Macro(ExprMacro {
+                attrs: Vec::new(),
+                mac: Macro {
+                    path,
+                    bang_token,
+                    delimiter,
+                    tokens,
+                },
+            }));
+        }
+
+        if input.peek(token::Brace) {
+            pat_struct(input, qself, path).map(Pat::Struct)
+        } else if input.peek(token::Paren) {
+            pat_tuple_struct(input, qself, path).map(Pat::TupleStruct)
+        } else if input.peek(Token![..]) {
+            pat_range(input, qself, path)
+        } else {
+            Ok(Pat::Path(ExprPath {
+                attrs: Vec::new(),
+                qself,
+                path,
+            }))
+        }
+    }
+
+    fn pat_wild(input: ParseStream) -> Result<PatWild> {
+        Ok(PatWild {
+            attrs: Vec::new(),
+            underscore_token: input.parse()?,
+        })
+    }
+
+    fn pat_box(begin: ParseBuffer, input: ParseStream) -> Result<Pat> {
+        input.parse::<Token![box]>()?;
+        Pat::parse_single(input)?;
+        Ok(Pat::Verbatim(verbatim::between(&begin, input)))
+    }
+
+    fn pat_ident(input: ParseStream) -> Result<PatIdent> {
+        Ok(PatIdent {
+            attrs: Vec::new(),
+            by_ref: input.parse()?,
+            mutability: input.parse()?,
+            ident: {
+                if input.peek(Token![self]) {
+                    input.call(Ident::parse_any)?
+                } else {
+                    input.parse()?
+                }
+            },
+            subpat: {
+                if input.peek(Token![@]) {
+                    let at_token: Token![@] = input.parse()?;
+                    let subpat = Pat::parse_single(input)?;
+                    Some((at_token, Box::new(subpat)))
+                } else {
+                    None
+                }
+            },
+        })
+    }
+
+    fn pat_tuple_struct(
+        input: ParseStream,
+        qself: Option<QSelf>,
+        path: Path,
+    ) -> Result<PatTupleStruct> {
+        let content;
+        let paren_token = parenthesized!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            elems.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(PatTupleStruct {
+            attrs: Vec::new(),
+            qself,
+            path,
+            paren_token,
+            elems,
+        })
+    }
+
+    fn pat_struct(input: ParseStream, qself: Option<QSelf>, path: Path) -> Result<PatStruct> {
+        let content;
+        let brace_token = braced!(content in input);
+
+        let mut fields = Punctuated::new();
+        let mut rest = None;
+        while !content.is_empty() {
+            let attrs = content.call(Attribute::parse_outer)?;
+            if content.peek(Token![..]) {
+                rest = Some(PatRest {
+                    attrs,
+                    dot2_token: content.parse()?,
+                });
+                break;
+            }
+            let mut value = content.call(field_pat)?;
+            value.attrs = attrs;
+            fields.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct: Token![,] = content.parse()?;
+            fields.push_punct(punct);
+        }
+
+        Ok(PatStruct {
+            attrs: Vec::new(),
+            qself,
+            path,
+            brace_token,
+            fields,
+            rest,
+        })
+    }
+
+    fn field_pat(input: ParseStream) -> Result<FieldPat> {
+        let begin = input.fork();
+        let boxed: Option<Token![box]> = input.parse()?;
+        let by_ref: Option<Token![ref]> = input.parse()?;
+        let mutability: Option<Token![mut]> = input.parse()?;
+
+        let member = if boxed.is_some() || by_ref.is_some() || mutability.is_some() {
+            input.parse().map(Member::Named)
+        } else {
+            input.parse()
+        }?;
+
+        if boxed.is_none() && by_ref.is_none() && mutability.is_none() && input.peek(Token![:])
+            || !member.is_named()
+        {
+            return Ok(FieldPat {
+                attrs: Vec::new(),
+                member,
+                colon_token: Some(input.parse()?),
+                pat: Box::new(Pat::parse_multi_with_leading_vert(input)?),
+            });
+        }
+
+        let ident = match member {
+            Member::Named(ident) => ident,
+            Member::Unnamed(_) => unreachable!(),
+        };
+
+        let pat = if boxed.is_some() {
+            Pat::Verbatim(verbatim::between(&begin, input))
+        } else {
+            Pat::Ident(PatIdent {
+                attrs: Vec::new(),
+                by_ref,
+                mutability,
+                ident: ident.clone(),
+                subpat: None,
+            })
+        };
+
+        Ok(FieldPat {
+            attrs: Vec::new(),
+            member: Member::Named(ident),
+            colon_token: None,
+            pat: Box::new(pat),
+        })
+    }
+
+    fn pat_range(input: ParseStream, qself: Option<QSelf>, path: Path) -> Result<Pat> {
+        let limits = RangeLimits::parse_obsolete(input)?;
+        let end = input.call(pat_range_bound)?;
+        if let (RangeLimits::Closed(_), None) = (&limits, &end) {
+            return Err(input.error("expected range upper bound"));
+        }
+        Ok(Pat::Range(ExprRange {
+            attrs: Vec::new(),
+            start: Some(Box::new(Expr::Path(ExprPath {
+                attrs: Vec::new(),
+                qself,
+                path,
+            }))),
+            limits,
+            end: end.map(PatRangeBound::into_expr),
+        }))
+    }
+
+    fn pat_range_half_open(input: ParseStream) -> Result<Pat> {
+        let limits: RangeLimits = input.parse()?;
+        let end = input.call(pat_range_bound)?;
+        if end.is_some() {
+            Ok(Pat::Range(ExprRange {
+                attrs: Vec::new(),
+                start: None,
+                limits,
+                end: end.map(PatRangeBound::into_expr),
+            }))
+        } else {
+            match limits {
+                RangeLimits::HalfOpen(dot2_token) => Ok(Pat::Rest(PatRest {
+                    attrs: Vec::new(),
+                    dot2_token,
+                })),
+                RangeLimits::Closed(_) => Err(input.error("expected range upper bound")),
+            }
+        }
+    }
+
+    fn pat_paren_or_tuple(input: ParseStream) -> Result<Pat> {
+        let content;
+        let paren_token = parenthesized!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            if content.is_empty() {
+                if elems.is_empty() && !matches!(value, Pat::Rest(_)) {
+                    return Ok(Pat::Paren(PatParen {
+                        attrs: Vec::new(),
+                        paren_token,
+                        pat: Box::new(value),
+                    }));
+                }
+                elems.push_value(value);
+                break;
+            }
+            elems.push_value(value);
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(Pat::Tuple(PatTuple {
+            attrs: Vec::new(),
+            paren_token,
+            elems,
+        }))
+    }
+
+    fn pat_reference(input: ParseStream) -> Result<PatReference> {
+        Ok(PatReference {
+            attrs: Vec::new(),
+            and_token: input.parse()?,
+            mutability: input.parse()?,
+            pat: Box::new(Pat::parse_single(input)?),
+        })
+    }
+
+    fn pat_lit_or_range(input: ParseStream) -> Result<Pat> {
+        let start = input.call(pat_range_bound)?.unwrap();
+        if input.peek(Token![..]) {
+            let limits = RangeLimits::parse_obsolete(input)?;
+            let end = input.call(pat_range_bound)?;
+            if let (RangeLimits::Closed(_), None) = (&limits, &end) {
+                return Err(input.error("expected range upper bound"));
+            }
+            Ok(Pat::Range(ExprRange {
+                attrs: Vec::new(),
+                start: Some(start.into_expr()),
+                limits,
+                end: end.map(PatRangeBound::into_expr),
+            }))
+        } else {
+            Ok(start.into_pat())
+        }
+    }
+
+    // Patterns that can appear on either side of a range pattern.
+    enum PatRangeBound {
+        Const(ExprConst),
+        Lit(ExprLit),
+        Path(ExprPath),
+    }
+
+    impl PatRangeBound {
+        fn into_expr(self) -> Box<Expr> {
+            Box::new(match self {
+                PatRangeBound::Const(pat) => Expr::Const(pat),
+                PatRangeBound::Lit(pat) => Expr::Lit(pat),
+                PatRangeBound::Path(pat) => Expr::Path(pat),
+            })
+        }
+
+        fn into_pat(self) -> Pat {
+            match self {
+                PatRangeBound::Const(pat) => Pat::Const(pat),
+                PatRangeBound::Lit(pat) => Pat::Lit(pat),
+                PatRangeBound::Path(pat) => Pat::Path(pat),
+            }
+        }
+    }
+
+    fn pat_range_bound(input: ParseStream) -> Result<Option<PatRangeBound>> {
+        if input.is_empty()
+            || input.peek(Token![|])
+            || input.peek(Token![=])
+            || input.peek(Token![:]) && !input.peek(Token![::])
+            || input.peek(Token![,])
+            || input.peek(Token![;])
+            || input.peek(Token![if])
+        {
+            return Ok(None);
+        }
+
+        let lookahead = input.lookahead1();
+        let expr = if lookahead.peek(Lit) {
+            PatRangeBound::Lit(input.parse()?)
+        } else if lookahead.peek(Ident)
+            || lookahead.peek(Token![::])
+            || lookahead.peek(Token![<])
+            || lookahead.peek(Token![self])
+            || lookahead.peek(Token![Self])
+            || lookahead.peek(Token![super])
+            || lookahead.peek(Token![crate])
+        {
+            PatRangeBound::Path(input.parse()?)
+        } else if lookahead.peek(Token![const]) {
+            PatRangeBound::Const(input.parse()?)
+        } else {
+            return Err(lookahead.error());
+        };
+
+        Ok(Some(expr))
+    }
+
+    fn pat_slice(input: ParseStream) -> Result<PatSlice> {
+        let content;
+        let bracket_token = bracketed!(content in input);
+
+        let mut elems = Punctuated::new();
+        while !content.is_empty() {
+            let value = Pat::parse_multi_with_leading_vert(&content)?;
+            match value {
+                Pat::Range(pat) if pat.start.is_none() || pat.end.is_none() => {
+                    let (start, end) = match pat.limits {
+                        RangeLimits::HalfOpen(dot_dot) => (dot_dot.spans[0], dot_dot.spans[1]),
+                        RangeLimits::Closed(dot_dot_eq) => {
+                            (dot_dot_eq.spans[0], dot_dot_eq.spans[2])
+                        }
+                    };
+                    let msg = "range pattern is not allowed unparenthesized inside slice pattern";
+                    return Err(error::new2(start, end, msg));
+                }
+                _ => {}
+            }
+            elems.push_value(value);
+            if content.is_empty() {
+                break;
+            }
+            let punct = content.parse()?;
+            elems.push_punct(punct);
+        }
+
+        Ok(PatSlice {
+            attrs: Vec::new(),
+            bracket_token,
+            elems,
+        })
+    }
+
+    fn pat_const(input: ParseStream) -> Result<TokenStream> {
+        let begin = input.fork();
+        input.parse::<Token![const]>()?;
+
+        let content;
+        braced!(content in input);
+        content.call(Attribute::parse_inner)?;
+        content.call(Block::parse_within)?;
+
+        Ok(verbatim::between(&begin, input))
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use crate::attr::FilterAttrs;
+    use crate::pat::{
+        FieldPat, Pat, PatIdent, PatOr, PatParen, PatReference, PatRest, PatSlice, PatStruct,
+        PatTuple, PatTupleStruct, PatType, PatWild,
+    };
+    use crate::path;
+    use crate::path::printing::PathStyle;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatIdent {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.by_ref.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.ident.to_tokens(tokens);
+            if let Some((at_token, subpat)) = &self.subpat {
+                at_token.to_tokens(tokens);
+                subpat.to_tokens(tokens);
+            }
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatOr {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.leading_vert.to_tokens(tokens);
+            self.cases.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatParen {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.paren_token.surround(tokens, |tokens| {
+                self.pat.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatReference {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.and_token.to_tokens(tokens);
+            self.mutability.to_tokens(tokens);
+            self.pat.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatRest {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.dot2_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatSlice {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.bracket_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            path::printing::print_qpath(tokens, &self.qself, &self.path, PathStyle::Expr);
+            self.brace_token.surround(tokens, |tokens| {
+                self.fields.to_tokens(tokens);
+                // NOTE: We need a comma before the dot2 token if it is present.
+                if !self.fields.empty_or_trailing() && self.rest.is_some() {
+                    <Token![,]>::default().to_tokens(tokens);
+                }
+                self.rest.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatTuple {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+                // If there is only one element, a trailing comma is needed to
+                // distinguish PatTuple from PatParen, unless this is `(..)`
+                // which is a tuple pattern even without comma.
+                if self.elems.len() == 1
+                    && !self.elems.trailing_punct()
+                    && !matches!(self.elems[0], Pat::Rest { .. })
+                {
+                    <Token![,]>::default().to_tokens(tokens);
+                }
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatTupleStruct {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            path::printing::print_qpath(tokens, &self.qself, &self.path, PathStyle::Expr);
+            self.paren_token.surround(tokens, |tokens| {
+                self.elems.to_tokens(tokens);
+            });
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatType {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.pat.to_tokens(tokens);
+            self.colon_token.to_tokens(tokens);
+            self.ty.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PatWild {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            self.underscore_token.to_tokens(tokens);
+        }
+    }
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for FieldPat {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.outer());
+            if let Some(colon_token) = &self.colon_token {
+                self.member.to_tokens(tokens);
+                colon_token.to_tokens(tokens);
+            }
+            self.pat.to_tokens(tokens);
+        }
+    }
+}