Struct TableGuards 

pub struct TableGuards {
    pub table_size: Option<u32>,
    pub base_byte_offset: Option<u32>,
    pub type_reject: Vec<Option<String>>,
    pub has_null_slots: bool,
    pub runtime_type_check: bool,
}

#642/#650: one table’s call_indirect guard inputs — see CallIndirectGuards for the layout contract and soundness argument.

Fields

table_size: Option<u32>

Compile-time size of this table (entries); None = no sound bound known (an imported table with growable limits).

base_byte_offset: Option<u32>

#650: byte offset of this table’s base within the contiguous R11 region — sum(size(0..N)) * 4, a compile-time constant. None when any PRECEDING table’s size is unknown (the base is then not a compile-time constant and the lowering declines).

type_reject: Vec<Option<String>>

Per expected-type index: None = closed-world type property VERIFIED against THIS table; Some(reason) = not verifiable (the lowering declines).

has_null_slots: bool

#664: whether this table’s image contains at least one uninitialized (null funcref) slot. WASM Core §4.4.8 requires a call_indirect reaching a null slot to TRAP — the closed-world type check verifies the INITIALIZED slots only, and the lowering must emit a runtime null check (pointer == 0 → trap) before the indirect branch when this is set. false for a fully-initialized table keeps today’s exact dispatch bytes (no null check) BY CONSTRUCTION. Only meaningful when the type verdict is None (verified); reject paths decline before it is consulted.

runtime_type_check: bool

#676: this table’s image is statically known but HETEROGENEOUS — its initialized slots span at least two distinct STRUCTURAL signature classes, so no expected type’s closed world can hold (type_reject[t] is Some for every t) — yet the mismatch trap (WASM Core §4.4.8) IS dischargeable at runtime: the type-id sidecar (see CallIndirectGuards) carries each slot’s structural class id, and the dispatch compares the indexed slot’s id against the expected type’s class id (a compile-time immediate), trapping on inequality. When set (and CallIndirectGuards::type_ids_byte_offset is known), the lowering emits that runtime check INSTEAD of declining. false keeps the pre-#676 behavior: verified tables dispatch unchecked (byte-identical), unverifiable tables decline.

Trait Implementations

impl Clone for TableGuards

fn clone(&self) -> TableGuards

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TableGuards

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

Formats the value using the given formatter.

impl Default for TableGuards

fn default() -> TableGuards

Returns the “default value” for a type.

impl Eq for TableGuards

impl PartialEq for TableGuards

fn eq(&self, other: &TableGuards) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for TableGuards