Enum Terminator 

pub enum Terminator {
    Jump {
        target: BlockId,
        range: SourceRange,
    },
    Branch {
        cond: Expr,
        then_blk: BlockId,
        else_blk: BlockId,
    },
    Switch {
        value: Expr,
        cases: Vec<(CaseRange, BlockId)>,
        default: BlockId,
        range: SourceRange,
    },
    Return {
        value: Option<Expr>,
        range: SourceRange,
    },
    Unreachable,
    InvalidTarget,
}

How a BasicBlock ends.

Variants

Jump

Control moves to another block.

Fields

target: BlockId

The block entered.

range: SourceRange

The construct the edge came from.

Branch

Control moves to one of two blocks depending on a condition.

Fields

cond: Expr

The controlling expression.

then_blk: BlockId

Entered when cond is non-zero.

else_blk: BlockId

Entered otherwise.

Switch

A switch dispatch — also what a computed goto becomes; see Labels as values.

Fields

value: Expr

The controlling expression, after the integer promotions.

cases: Vec<(CaseRange, BlockId)>

The case labels and the blocks they enter, in source order.

default: BlockId

Where default: goes — past the statement when there is none.

range: SourceRange

Where the statement was written.

Return

The function returns.

Fields

value: Option<Expr>

The returned value.

range: SourceRange

Where the statement was written.

Unreachable

Control never gets here.

Only reachable through a bug in this module, and emitted as unreachable!() so that such a bug is loud rather than silent.

InvalidTarget

The default of a computed goto’s dispatch: a value that is no label’s number, which is undefined behaviour in C.

Emitted as unreachable!() in a build with debug assertions, which catches the bug, and as unreachable_unchecked() otherwise — what GCC assumes too, and what lets the match be a bare jump table.

Trait Implementations

impl Clone for Terminator

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Terminator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.