Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 775 insertions, 0 deletions

diff --git a/rust/syn/fixup.rs b/rust/syn/fixup.rs
new file mode 100644
index 000000000..79b6d7618
--- /dev/null
+++ b/rust/syn/fixup.rs
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use crate::classify;
+use crate::expr::Expr;
+#[cfg(feature = "full")]
+use crate::expr::{
+    ExprBreak, ExprRange, ExprRawAddr, ExprReference, ExprReturn, ExprUnary, ExprYield,
+};
+use crate::precedence::Precedence;
+#[cfg(feature = "full")]
+use crate::ty::ReturnType;
+
+pub(crate) struct FixupContext {
+    #[cfg(feature = "full")]
+    previous_operator: Precedence,
+    #[cfg(feature = "full")]
+    next_operator: Precedence,
+
+    // Print expression such that it can be parsed back as a statement
+    // consisting of the original expression.
+    //
+    // The effect of this is for binary operators in statement position to set
+    // `leftmost_subexpression_in_stmt` when printing their left-hand operand.
+    //
+    //     (match x {}) - 1;  // match needs parens when LHS of binary operator
+    //
+    //     match x {};  // not when its own statement
+    //
+    #[cfg(feature = "full")]
+    stmt: bool,
+
+    // This is the difference between:
+    //
+    //     (match x {}) - 1;  // subexpression needs parens
+    //
+    //     let _ = match x {} - 1;  // no parens
+    //
+    // There are 3 distinguishable contexts in which `print_expr` might be
+    // called with the expression `$match` as its argument, where `$match`
+    // represents an expression of kind `ExprKind::Match`:
+    //
+    //   - stmt=false leftmost_subexpression_in_stmt=false
+    //
+    //     Example: `let _ = $match - 1;`
+    //
+    //     No parentheses required.
+    //
+    //   - stmt=false leftmost_subexpression_in_stmt=true
+    //
+    //     Example: `$match - 1;`
+    //
+    //     Must parenthesize `($match)`, otherwise parsing back the output as a
+    //     statement would terminate the statement after the closing brace of
+    //     the match, parsing `-1;` as a separate statement.
+    //
+    //   - stmt=true leftmost_subexpression_in_stmt=false
+    //
+    //     Example: `$match;`
+    //
+    //     No parentheses required.
+    #[cfg(feature = "full")]
+    leftmost_subexpression_in_stmt: bool,
+
+    // Print expression such that it can be parsed as a match arm.
+    //
+    // This is almost equivalent to `stmt`, but the grammar diverges a tiny bit
+    // between statements and match arms when it comes to braced macro calls.
+    // Macro calls with brace delimiter terminate a statement without a
+    // semicolon, but do not terminate a match-arm without comma.
+    //
+    //     m! {} - 1;  // two statements: a macro call followed by -1 literal
+    //
+    //     match () {
+    //         _ => m! {} - 1,  // binary subtraction operator
+    //     }
+    //
+    #[cfg(feature = "full")]
+    match_arm: bool,
+
+    // This is almost equivalent to `leftmost_subexpression_in_stmt`, other than
+    // for braced macro calls.
+    //
+    // If we have `m! {} - 1` as an expression, the leftmost subexpression
+    // `m! {}` will need to be parenthesized in the statement case but not the
+    // match-arm case.
+    //
+    //     (m! {}) - 1;  // subexpression needs parens
+    //
+    //     match () {
+    //         _ => m! {} - 1,  // no parens
+    //     }
+    //
+    #[cfg(feature = "full")]
+    leftmost_subexpression_in_match_arm: bool,
+
+    // This is the difference between:
+    //
+    //     if let _ = (Struct {}) {}  // needs parens
+    //
+    //     match () {
+    //         () if let _ = Struct {} => {}  // no parens
+    //     }
+    //
+    #[cfg(feature = "full")]
+    condition: bool,
+
+    // This is the difference between:
+    //
+    //     if break Struct {} == (break) {}  // needs parens
+    //
+    //     if break break == Struct {} {}  // no parens
+    //
+    #[cfg(feature = "full")]
+    rightmost_subexpression_in_condition: bool,
+
+    // This is the difference between:
+    //
+    //     if break ({ x }).field + 1 {}  needs parens
+    //
+    //     if break 1 + { x }.field {}  // no parens
+    //
+    #[cfg(feature = "full")]
+    leftmost_subexpression_in_optional_operand: bool,
+
+    // This is the difference between:
+    //
+    //     let _ = (return) - 1;  // without paren, this would return -1
+    //
+    //     let _ = return + 1;  // no paren because '+' cannot begin expr
+    //
+    #[cfg(feature = "full")]
+    next_operator_can_begin_expr: bool,
+
+    // This is the difference between:
+    //
+    //     let _ = 1 + return 1;  // no parens if rightmost subexpression
+    //
+    //     let _ = 1 + (return 1) + 1;  // needs parens
+    //
+    #[cfg(feature = "full")]
+    next_operator_can_continue_expr: bool,
+
+    // This is the difference between:
+    //
+    //     let _ = x as u8 + T;
+    //
+    //     let _ = (x as u8) < T;
+    //
+    // Without parens, the latter would want to parse `u8<T...` as a type.
+    next_operator_can_begin_generics: bool,
+}
+
+impl FixupContext {
+    /// The default amount of fixing is minimal fixing. Fixups should be turned
+    /// on in a targeted fashion where needed.
+    pub const NONE: Self = FixupContext {
+        #[cfg(feature = "full")]
+        previous_operator: Precedence::MIN,
+        #[cfg(feature = "full")]
+        next_operator: Precedence::MIN,
+        #[cfg(feature = "full")]
+        stmt: false,
+        #[cfg(feature = "full")]
+        leftmost_subexpression_in_stmt: false,
+        #[cfg(feature = "full")]
+        match_arm: false,
+        #[cfg(feature = "full")]
+        leftmost_subexpression_in_match_arm: false,
+        #[cfg(feature = "full")]
+        condition: false,
+        #[cfg(feature = "full")]
+        rightmost_subexpression_in_condition: false,
+        #[cfg(feature = "full")]
+        leftmost_subexpression_in_optional_operand: false,
+        #[cfg(feature = "full")]
+        next_operator_can_begin_expr: false,
+        #[cfg(feature = "full")]
+        next_operator_can_continue_expr: false,
+        next_operator_can_begin_generics: false,
+    };
+
+    /// Create the initial fixup for printing an expression in statement
+    /// position.
+    #[cfg(feature = "full")]
+    pub fn new_stmt() -> Self {
+        FixupContext {
+            stmt: true,
+            ..FixupContext::NONE
+        }
+    }
+
+    /// Create the initial fixup for printing an expression as the right-hand
+    /// side of a match arm.
+    #[cfg(feature = "full")]
+    pub fn new_match_arm() -> Self {
+        FixupContext {
+            match_arm: true,
+            ..FixupContext::NONE
+        }
+    }
+
+    /// Create the initial fixup for printing an expression as the "condition"
+    /// of an `if` or `while`. There are a few other positions which are
+    /// grammatically equivalent and also use this, such as the iterator
+    /// expression in `for` and the scrutinee in `match`.
+    #[cfg(feature = "full")]
+    pub fn new_condition() -> Self {
+        FixupContext {
+            condition: true,
+            rightmost_subexpression_in_condition: true,
+            ..FixupContext::NONE
+        }
+    }
+
+    /// Transform this fixup into the one that should apply when printing the
+    /// leftmost subexpression of the current expression.
+    ///
+    /// The leftmost subexpression is any subexpression that has the same first
+    /// token as the current expression, but has a different last token.
+    ///
+    /// For example in `$a + $b` and `$a.method()`, the subexpression `$a` is a
+    /// leftmost subexpression.
+    ///
+    /// Not every expression has a leftmost subexpression. For example neither
+    /// `-$a` nor `[$a]` have one.
+    pub fn leftmost_subexpression_with_operator(
+        self,
+        expr: &Expr,
+        #[cfg(feature = "full")] next_operator_can_begin_expr: bool,
+        next_operator_can_begin_generics: bool,
+        #[cfg(feature = "full")] precedence: Precedence,
+    ) -> (Precedence, Self) {
+        let fixup = FixupContext {
+            #[cfg(feature = "full")]
+            next_operator: precedence,
+            #[cfg(feature = "full")]
+            stmt: false,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_stmt: self.stmt || self.leftmost_subexpression_in_stmt,
+            #[cfg(feature = "full")]
+            match_arm: false,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_match_arm: self.match_arm
+                || self.leftmost_subexpression_in_match_arm,
+            #[cfg(feature = "full")]
+            rightmost_subexpression_in_condition: false,
+            #[cfg(feature = "full")]
+            next_operator_can_begin_expr,
+            #[cfg(feature = "full")]
+            next_operator_can_continue_expr: true,
+            next_operator_can_begin_generics,
+            ..self
+        };
+
+        (fixup.leftmost_subexpression_precedence(expr), fixup)
+    }
+
+    /// Transform this fixup into the one that should apply when printing a
+    /// leftmost subexpression followed by a `.` or `?` token, which confer
+    /// different statement boundary rules compared to other leftmost
+    /// subexpressions.
+    pub fn leftmost_subexpression_with_dot(self, expr: &Expr) -> (Precedence, Self) {
+        let fixup = FixupContext {
+            #[cfg(feature = "full")]
+            next_operator: Precedence::Unambiguous,
+            #[cfg(feature = "full")]
+            stmt: self.stmt || self.leftmost_subexpression_in_stmt,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_stmt: false,
+            #[cfg(feature = "full")]
+            match_arm: self.match_arm || self.leftmost_subexpression_in_match_arm,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_match_arm: false,
+            #[cfg(feature = "full")]
+            rightmost_subexpression_in_condition: false,
+            #[cfg(feature = "full")]
+            next_operator_can_begin_expr: false,
+            #[cfg(feature = "full")]
+            next_operator_can_continue_expr: true,
+            next_operator_can_begin_generics: false,
+            ..self
+        };
+
+        (fixup.leftmost_subexpression_precedence(expr), fixup)
+    }
+
+    fn leftmost_subexpression_precedence(self, expr: &Expr) -> Precedence {
+        #[cfg(feature = "full")]
+        if !self.next_operator_can_begin_expr || self.next_operator == Precedence::Range {
+            if let Scan::Bailout = scan_right(expr, self, Precedence::MIN, 0, 0) {
+                if scan_left(expr, self) {
+                    return Precedence::Unambiguous;
+                }
+            }
+        }
+
+        self.precedence(expr)
+    }
+
+    /// Transform this fixup into the one that should apply when printing the
+    /// rightmost subexpression of the current expression.
+    ///
+    /// The rightmost subexpression is any subexpression that has a different
+    /// first token than the current expression, but has the same last token.
+    ///
+    /// For example in `$a + $b` and `-$b`, the subexpression `$b` is a
+    /// rightmost subexpression.
+    ///
+    /// Not every expression has a rightmost subexpression. For example neither
+    /// `[$b]` nor `$a.f($b)` have one.
+    pub fn rightmost_subexpression(
+        self,
+        expr: &Expr,
+        #[cfg(feature = "full")] precedence: Precedence,
+    ) -> (Precedence, Self) {
+        let fixup = self.rightmost_subexpression_fixup(
+            #[cfg(feature = "full")]
+            false,
+            #[cfg(feature = "full")]
+            false,
+            #[cfg(feature = "full")]
+            precedence,
+        );
+        (fixup.rightmost_subexpression_precedence(expr), fixup)
+    }
+
+    pub fn rightmost_subexpression_fixup(
+        self,
+        #[cfg(feature = "full")] reset_allow_struct: bool,
+        #[cfg(feature = "full")] optional_operand: bool,
+        #[cfg(feature = "full")] precedence: Precedence,
+    ) -> Self {
+        FixupContext {
+            #[cfg(feature = "full")]
+            previous_operator: precedence,
+            #[cfg(feature = "full")]
+            stmt: false,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_stmt: false,
+            #[cfg(feature = "full")]
+            match_arm: false,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_match_arm: false,
+            #[cfg(feature = "full")]
+            condition: self.condition && !reset_allow_struct,
+            #[cfg(feature = "full")]
+            leftmost_subexpression_in_optional_operand: self.condition && optional_operand,
+            ..self
+        }
+    }
+
+    pub fn rightmost_subexpression_precedence(self, expr: &Expr) -> Precedence {
+        let default_prec = self.precedence(expr);
+
+        #[cfg(feature = "full")]
+        if match self.previous_operator {
+            Precedence::Assign | Precedence::Let | Precedence::Prefix => {
+                default_prec < self.previous_operator
+            }
+            _ => default_prec <= self.previous_operator,
+        } && match self.next_operator {
+            Precedence::Range | Precedence::Or | Precedence::And => true,
+            _ => !self.next_operator_can_begin_expr,
+        } {
+            if let Scan::Bailout | Scan::Fail = scan_right(expr, self, self.previous_operator, 1, 0)
+            {
+                if scan_left(expr, self) {
+                    return Precedence::Prefix;
+                }
+            }
+        }
+
+        default_prec
+    }
+
+    /// Determine whether parentheses are needed around the given expression to
+    /// head off the early termination of a statement or condition.
+    #[cfg(feature = "full")]
+    pub fn parenthesize(self, expr: &Expr) -> bool {
+        (self.leftmost_subexpression_in_stmt && !classify::requires_semi_to_be_stmt(expr))
+            || ((self.stmt || self.leftmost_subexpression_in_stmt) && matches!(expr, Expr::Let(_)))
+            || (self.leftmost_subexpression_in_match_arm
+                && !classify::requires_comma_to_be_match_arm(expr))
+            || (self.condition && matches!(expr, Expr::Struct(_)))
+            || (self.rightmost_subexpression_in_condition
+                && matches!(
+                    expr,
+                    Expr::Return(ExprReturn { expr: None, .. })
+                        | Expr::Yield(ExprYield { expr: None, .. })
+                ))
+            || (self.rightmost_subexpression_in_condition
+                && !self.condition
+                && matches!(
+                    expr,
+                    Expr::Break(ExprBreak { expr: None, .. })
+                        | Expr::Path(_)
+                        | Expr::Range(ExprRange { end: None, .. })
+                ))
+            || (self.leftmost_subexpression_in_optional_operand
+                && matches!(expr, Expr::Block(expr) if expr.attrs.is_empty() && expr.label.is_none()))
+    }
+
+    /// Determines the effective precedence of a subexpression. Some expressions
+    /// have higher or lower precedence when adjacent to particular operators.
+    fn precedence(self, expr: &Expr) -> Precedence {
+        #[cfg(feature = "full")]
+        if self.next_operator_can_begin_expr {
+            // Decrease precedence of value-less jumps when followed by an
+            // operator that would otherwise get interpreted as beginning a
+            // value for the jump.
+            if let Expr::Break(ExprBreak { expr: None, .. })
+            | Expr::Return(ExprReturn { expr: None, .. })
+            | Expr::Yield(ExprYield { expr: None, .. }) = expr
+            {
+                return Precedence::Jump;
+            }
+        }
+
+        #[cfg(feature = "full")]
+        if !self.next_operator_can_continue_expr {
+            match expr {
+                // Increase precedence of expressions that extend to the end of
+                // current statement or group.
+                Expr::Break(_)
+                | Expr::Closure(_)
+                | Expr::Let(_)
+                | Expr::Return(_)
+                | Expr::Yield(_) => {
+                    return Precedence::Prefix;
+                }
+                Expr::Range(e) if e.start.is_none() => return Precedence::Prefix,
+                _ => {}
+            }
+        }
+
+        if self.next_operator_can_begin_generics {
+            if let Expr::Cast(cast) = expr {
+                if classify::trailing_unparameterized_path(&cast.ty) {
+                    return Precedence::MIN;
+                }
+            }
+        }
+
+        Precedence::of(expr)
+    }
+}
+
+impl Copy for FixupContext {}
+
+impl Clone for FixupContext {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+#[cfg(feature = "full")]
+enum Scan {
+    Fail,
+    Bailout,
+    Consume,
+}
+
+#[cfg(feature = "full")]
+impl Copy for Scan {}
+
+#[cfg(feature = "full")]
+impl Clone for Scan {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+#[cfg(feature = "full")]
+impl PartialEq for Scan {
+    fn eq(&self, other: &Self) -> bool {
+        *self as u8 == *other as u8
+    }
+}
+
+#[cfg(feature = "full")]
+fn scan_left(expr: &Expr, fixup: FixupContext) -> bool {
+    match expr {
+        Expr::Assign(_) => fixup.previous_operator <= Precedence::Assign,
+        Expr::Binary(e) => match Precedence::of_binop(&e.op) {
+            Precedence::Assign => fixup.previous_operator <= Precedence::Assign,
+            binop_prec => fixup.previous_operator < binop_prec,
+        },
+        Expr::Cast(_) => fixup.previous_operator < Precedence::Cast,
+        Expr::Range(e) => e.start.is_none() || fixup.previous_operator < Precedence::Assign,
+        _ => true,
+    }
+}
+
+#[cfg(feature = "full")]
+fn scan_right(
+    expr: &Expr,
+    fixup: FixupContext,
+    precedence: Precedence,
+    fail_offset: u8,
+    bailout_offset: u8,
+) -> Scan {
+    let consume_by_precedence = if match precedence {
+        Precedence::Assign | Precedence::Compare => precedence <= fixup.next_operator,
+        _ => precedence < fixup.next_operator,
+    } || fixup.next_operator == Precedence::MIN
+    {
+        Scan::Consume
+    } else {
+        Scan::Bailout
+    };
+    if fixup.parenthesize(expr) {
+        return consume_by_precedence;
+    }
+    match expr {
+        Expr::Assign(e) if e.attrs.is_empty() => {
+            if match fixup.next_operator {
+                Precedence::Unambiguous => fail_offset >= 2,
+                _ => bailout_offset >= 1,
+            } {
+                return Scan::Consume;
+            }
+            let right_fixup = fixup.rightmost_subexpression_fixup(false, false, Precedence::Assign);
+            let scan = scan_right(
+                &e.right,
+                right_fixup,
+                Precedence::Assign,
+                match fixup.next_operator {
+                    Precedence::Unambiguous => fail_offset,
+                    _ => 1,
+                },
+                1,
+            );
+            if let Scan::Bailout | Scan::Consume = scan {
+                Scan::Consume
+            } else if let Precedence::Unambiguous = fixup.next_operator {
+                Scan::Fail
+            } else {
+                Scan::Bailout
+            }
+        }
+        Expr::Binary(e) if e.attrs.is_empty() => {
+            if match fixup.next_operator {
+                Precedence::Unambiguous => {
+                    fail_offset >= 2
+                        && (consume_by_precedence == Scan::Consume || bailout_offset >= 1)
+                }
+                _ => bailout_offset >= 1,
+            } {
+                return Scan::Consume;
+            }
+            let binop_prec = Precedence::of_binop(&e.op);
+            if binop_prec == Precedence::Compare && fixup.next_operator == Precedence::Compare {
+                return Scan::Consume;
+            }
+            let right_fixup = fixup.rightmost_subexpression_fixup(false, false, binop_prec);
+            let scan = scan_right(
+                &e.right,
+                right_fixup,
+                binop_prec,
+                match fixup.next_operator {
+                    Precedence::Unambiguous => fail_offset,
+                    _ => 1,
+                },
+                consume_by_precedence as u8 - Scan::Bailout as u8,
+            );
+            match scan {
+                Scan::Fail => {}
+                Scan::Bailout => return consume_by_precedence,
+                Scan::Consume => return Scan::Consume,
+            }
+            let right_needs_group = binop_prec != Precedence::Assign
+                && right_fixup.rightmost_subexpression_precedence(&e.right) <= binop_prec;
+            if right_needs_group {
+                consume_by_precedence
+            } else if let (Scan::Fail, Precedence::Unambiguous) = (scan, fixup.next_operator) {
+                Scan::Fail
+            } else {
+                Scan::Bailout
+            }
+        }
+        Expr::RawAddr(ExprRawAddr { expr, .. })
+        | Expr::Reference(ExprReference { expr, .. })
+        | Expr::Unary(ExprUnary { expr, .. }) => {
+            if match fixup.next_operator {
+                Precedence::Unambiguous => {
+                    fail_offset >= 2
+                        && (consume_by_precedence == Scan::Consume || bailout_offset >= 1)
+                }
+                _ => bailout_offset >= 1,
+            } {
+                return Scan::Consume;
+            }
+            let right_fixup = fixup.rightmost_subexpression_fixup(false, false, Precedence::Prefix);
+            let scan = scan_right(
+                expr,
+                right_fixup,
+                precedence,
+                match fixup.next_operator {
+                    Precedence::Unambiguous => fail_offset,
+                    _ => 1,
+                },
+                consume_by_precedence as u8 - Scan::Bailout as u8,
+            );
+            match scan {
+                Scan::Fail => {}
+                Scan::Bailout => return consume_by_precedence,
+                Scan::Consume => return Scan::Consume,
+            }
+            if right_fixup.rightmost_subexpression_precedence(expr) < Precedence::Prefix {
+                consume_by_precedence
+            } else if let (Scan::Fail, Precedence::Unambiguous) = (scan, fixup.next_operator) {
+                Scan::Fail
+            } else {
+                Scan::Bailout
+            }
+        }
+        Expr::Range(e) if e.attrs.is_empty() => match &e.end {
+            Some(end) => {
+                if fail_offset >= 2 {
+                    return Scan::Consume;
+                }
+                let right_fixup =
+                    fixup.rightmost_subexpression_fixup(false, true, Precedence::Range);
+                let scan = scan_right(
+                    end,
+                    right_fixup,
+                    Precedence::Range,
+                    fail_offset,
+                    match fixup.next_operator {
+                        Precedence::Assign | Precedence::Range => 0,
+                        _ => 1,
+                    },
+                );
+                if match (scan, fixup.next_operator) {
+                    (Scan::Fail, _) => false,
+                    (Scan::Bailout, Precedence::Assign | Precedence::Range) => false,
+                    (Scan::Bailout | Scan::Consume, _) => true,
+                } {
+                    return Scan::Consume;
+                }
+                if right_fixup.rightmost_subexpression_precedence(end) <= Precedence::Range {
+                    Scan::Consume
+                } else {
+                    Scan::Fail
+                }
+            }
+            None => {
+                if fixup.next_operator_can_begin_expr {
+                    Scan::Consume
+                } else {
+                    Scan::Fail
+                }
+            }
+        },
+        Expr::Break(e) => match &e.expr {
+            Some(value) => {
+                if bailout_offset >= 1 || e.label.is_none() && classify::expr_leading_label(value) {
+                    return Scan::Consume;
+                }
+                let right_fixup = fixup.rightmost_subexpression_fixup(true, true, Precedence::Jump);
+                match scan_right(value, right_fixup, Precedence::Jump, 1, 1) {
+                    Scan::Fail => Scan::Bailout,
+                    Scan::Bailout | Scan::Consume => Scan::Consume,
+                }
+            }
+            None => match fixup.next_operator {
+                Precedence::Assign if precedence > Precedence::Assign => Scan::Fail,
+                _ => Scan::Consume,
+            },
+        },
+        Expr::Return(ExprReturn { expr, .. }) | Expr::Yield(ExprYield { expr, .. }) => match expr {
+            Some(e) => {
+                if bailout_offset >= 1 {
+                    return Scan::Consume;
+                }
+                let right_fixup =
+                    fixup.rightmost_subexpression_fixup(true, false, Precedence::Jump);
+                match scan_right(e, right_fixup, Precedence::Jump, 1, 1) {
+                    Scan::Fail => Scan::Bailout,
+                    Scan::Bailout | Scan::Consume => Scan::Consume,
+                }
+            }
+            None => match fixup.next_operator {
+                Precedence::Assign if precedence > Precedence::Assign => Scan::Fail,
+                _ => Scan::Consume,
+            },
+        },
+        Expr::Closure(e) => {
+            if matches!(e.output, ReturnType::Default)
+                || matches!(&*e.body, Expr::Block(body) if body.attrs.is_empty() && body.label.is_none())
+            {
+                if bailout_offset >= 1 {
+                    return Scan::Consume;
+                }
+                let right_fixup =
+                    fixup.rightmost_subexpression_fixup(false, false, Precedence::Jump);
+                match scan_right(&e.body, right_fixup, Precedence::Jump, 1, 1) {
+                    Scan::Fail => Scan::Bailout,
+                    Scan::Bailout | Scan::Consume => Scan::Consume,
+                }
+            } else {
+                Scan::Consume
+            }
+        }
+        Expr::Let(e) => {
+            if bailout_offset >= 1 {
+                return Scan::Consume;
+            }
+            let right_fixup = fixup.rightmost_subexpression_fixup(false, false, Precedence::Let);
+            let scan = scan_right(
+                &e.expr,
+                right_fixup,
+                Precedence::Let,
+                1,
+                if fixup.next_operator < Precedence::Let {
+                    0
+                } else {
+                    1
+                },
+            );
+            match scan {
+                Scan::Fail | Scan::Bailout if fixup.next_operator < Precedence::Let => {
+                    return Scan::Bailout;
+                }
+                Scan::Consume => return Scan::Consume,
+                _ => {}
+            }
+            if right_fixup.rightmost_subexpression_precedence(&e.expr) < Precedence::Let {
+                Scan::Consume
+            } else if let Scan::Fail = scan {
+                Scan::Bailout
+            } else {
+                Scan::Consume
+            }
+        }
+        Expr::Array(_)
+        | Expr::Assign(_)
+        | Expr::Async(_)
+        | Expr::Await(_)
+        | Expr::Binary(_)
+        | Expr::Block(_)
+        | Expr::Call(_)
+        | Expr::Cast(_)
+        | Expr::Const(_)
+        | Expr::Continue(_)
+        | Expr::Field(_)
+        | Expr::ForLoop(_)
+        | Expr::Group(_)
+        | Expr::If(_)
+        | Expr::Index(_)
+        | Expr::Infer(_)
+        | Expr::Lit(_)
+        | Expr::Loop(_)
+        | Expr::Macro(_)
+        | Expr::Match(_)
+        | Expr::MethodCall(_)
+        | Expr::Paren(_)
+        | Expr::Path(_)
+        | Expr::Range(_)
+        | Expr::Repeat(_)
+        | Expr::Struct(_)
+        | Expr::Try(_)
+        | Expr::TryBlock(_)
+        | Expr::Tuple(_)
+        | Expr::Unsafe(_)
+        | Expr::Verbatim(_)
+        | Expr::While(_) => match fixup.next_operator {
+            Precedence::Assign | Precedence::Range if precedence == Precedence::Range => Scan::Fail,
+            _ if precedence == Precedence::Let && fixup.next_operator < Precedence::Let => {
+                Scan::Fail
+            }
+            _ => consume_by_precedence,
+        },
+    }
+}