Struct CallIndirectGuards 

pub struct CallIndirectGuards {
    pub tables: Vec<TableGuards>,
}

#642/#650: everything the call_indirect lowering needs to emit its guards — computed once per module by DecodedModule::call_indirect_guards and threaded to the instruction selector via CompileConfig.

The R11 multi-table layout contract (#650)

The runtime/harness links every funcref table as ONE contiguous region of raw 4-byte code pointers based at R11, in declaration order (imported tables first): table 0 at R11 + 0, table N at R11 + sum(size(0..N)) * 4. The offsets are compile-time constants because tables are provably fixed-size (table.grow/table.set are unsupported ops whose functions loud-skip at decode — #642). A single-table module degenerates to the pre-#650 contract (table 0 at R11, offset 0) BY CONSTRUCTION, keeping its emitted bytes identical.

WASM Core §4.4.8 requires call_indirect to trap when index >= table.size and when the callee’s type does not match the instruction’s expected type. The region stores no size fields and no type ids, so, per table:

• the BOUNDS check is emitted at runtime against THAT table’s compile-time table_size immediate (sound: fixed-size, see above), and
• the TYPE check is discharged at COMPILE time: for expected type t, tables[n].type_reject[t] is None only when every INITIALIZED slot of table n verifiably holds a function whose signature structurally equals type t (the closed-world property — no runtime mismatch is then possible). Otherwise it holds the reason, and the lowering declines LOUDLY rather than emit an unchecked indirect branch, and
• a NULL (uninitialized) slot traps at RUNTIME (#664): the layout contract requires the runtime/harness to link every uninitialized slot as a ZERO word (null funcref has no code address; 0 is never a valid function pointer in the region), and when has_null_slots is set the dispatch emits a null check on the loaded pointer (CMP #0 → trap) between the bounds guard and the indirect branch. A fully-initialized table (has_null_slots == false) keeps the pre-#664 dispatch bytes identical BY CONSTRUCTION.

Fields

tables: Vec<TableGuards>

Per-table guard inputs, indexed by table index (imports first). The default (empty — no module context) DECLINES every call_indirect.

Implementations

impl CallIndirectGuards

pub fn single_table( table_size: Option<u32>, type_reject: Vec<Option<String>>, ) -> Self

Single-table (table 0 at R11 offset 0) guards — the pre-#650 shape, used by tests and single-table call sites.

Trait Implementations

impl Clone for CallIndirectGuards

fn clone(&self) -> CallIndirectGuards

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CallIndirectGuards

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

Formats the value using the given formatter.

impl Default for CallIndirectGuards

fn default() -> CallIndirectGuards

Returns the “default value” for a type.

impl Eq for CallIndirectGuards

impl PartialEq for CallIndirectGuards

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for CallIndirectGuards