Trait cranelift_wasm::FuncEnvironment

pub trait FuncEnvironment: TargetEnvironment {
    // Required methods
    fn make_global(
        &mut self,
        func: &mut Function,
        index: GlobalIndex
    ) -> WasmResult<GlobalVariable>;
    fn heaps(&self) -> &PrimaryMap<Heap, HeapData>;
    fn make_heap(
        &mut self,
        func: &mut Function,
        index: MemoryIndex
    ) -> WasmResult<Heap>;
    fn make_indirect_sig(
        &mut self,
        func: &mut Function,
        index: TypeIndex
    ) -> WasmResult<SigRef>;
    fn make_direct_func(
        &mut self,
        func: &mut Function,
        index: FuncIndex
    ) -> WasmResult<FuncRef>;
    fn translate_call_indirect(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        table_index: TableIndex,
        sig_index: TypeIndex,
        sig_ref: SigRef,
        callee: Value,
        call_args: &[Value]
    ) -> WasmResult<Option<Inst>>;
    fn translate_return_call_indirect(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        table_index: TableIndex,
        sig_index: TypeIndex,
        sig_ref: SigRef,
        callee: Value,
        call_args: &[Value]
    ) -> WasmResult<()>;
    fn translate_return_call_ref(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        sig_ref: SigRef,
        callee: Value,
        call_args: &[Value]
    ) -> WasmResult<()>;
    fn translate_call_ref(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        sig_ref: SigRef,
        callee: Value,
        call_args: &[Value]
    ) -> WasmResult<Inst>;
    fn translate_memory_grow(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap,
        val: Value
    ) -> WasmResult<Value>;
    fn translate_memory_size(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap
    ) -> WasmResult<Value>;
    fn translate_memory_copy(
        &mut self,
        pos: FuncCursor<'_>,
        src_index: MemoryIndex,
        src_heap: Heap,
        dst_index: MemoryIndex,
        dst_heap: Heap,
        dst: Value,
        src: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_memory_fill(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap,
        dst: Value,
        val: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_memory_init(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap,
        seg_index: u32,
        dst: Value,
        src: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_data_drop(
        &mut self,
        pos: FuncCursor<'_>,
        seg_index: u32
    ) -> WasmResult<()>;
    fn translate_table_size(
        &mut self,
        pos: FuncCursor<'_>,
        index: TableIndex
    ) -> WasmResult<Value>;
    fn translate_table_grow(
        &mut self,
        pos: FuncCursor<'_>,
        table_index: TableIndex,
        delta: Value,
        init_value: Value
    ) -> WasmResult<Value>;
    fn translate_table_get(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        table_index: TableIndex,
        index: Value
    ) -> WasmResult<Value>;
    fn translate_table_set(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        table_index: TableIndex,
        value: Value,
        index: Value
    ) -> WasmResult<()>;
    fn translate_table_copy(
        &mut self,
        pos: FuncCursor<'_>,
        dst_table_index: TableIndex,
        src_table_index: TableIndex,
        dst: Value,
        src: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_table_fill(
        &mut self,
        pos: FuncCursor<'_>,
        table_index: TableIndex,
        dst: Value,
        val: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_table_init(
        &mut self,
        pos: FuncCursor<'_>,
        seg_index: u32,
        table_index: TableIndex,
        dst: Value,
        src: Value,
        len: Value
    ) -> WasmResult<()>;
    fn translate_elem_drop(
        &mut self,
        pos: FuncCursor<'_>,
        seg_index: u32
    ) -> WasmResult<()>;
    fn translate_ref_func(
        &mut self,
        pos: FuncCursor<'_>,
        func_index: FuncIndex
    ) -> WasmResult<Value>;
    fn translate_custom_global_get(
        &mut self,
        pos: FuncCursor<'_>,
        global_index: GlobalIndex
    ) -> WasmResult<Value>;
    fn translate_custom_global_set(
        &mut self,
        pos: FuncCursor<'_>,
        global_index: GlobalIndex,
        val: Value
    ) -> WasmResult<()>;
    fn translate_atomic_wait(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap,
        addr: Value,
        expected: Value,
        timeout: Value
    ) -> WasmResult<Value>;
    fn translate_atomic_notify(
        &mut self,
        pos: FuncCursor<'_>,
        index: MemoryIndex,
        heap: Heap,
        addr: Value,
        count: Value
    ) -> WasmResult<Value>;
    fn translate_ref_i31(
        &mut self,
        pos: FuncCursor<'_>,
        val: Value
    ) -> WasmResult<Value>;
    fn translate_i31_get_s(
        &mut self,
        pos: FuncCursor<'_>,
        i31ref: Value
    ) -> WasmResult<Value>;
    fn translate_i31_get_u(
        &mut self,
        pos: FuncCursor<'_>,
        i31ref: Value
    ) -> WasmResult<Value>;

    // Provided methods
    fn is_wasm_parameter(&self, signature: &Signature, index: usize) -> bool { ... }
    fn is_wasm_return(&self, signature: &Signature, index: usize) -> bool { ... }
    fn after_locals(&mut self, num_locals_defined: usize) { ... }
    fn translate_call(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        _callee_index: FuncIndex,
        callee: FuncRef,
        call_args: &[Value]
    ) -> WasmResult<Inst> { ... }
    fn translate_return_call(
        &mut self,
        builder: &mut FunctionBuilder<'_>,
        _callee_index: FuncIndex,
        callee: FuncRef,
        call_args: &[Value]
    ) -> WasmResult<()> { ... }
    fn translate_ref_null(
        &mut self,
        pos: FuncCursor<'_>,
        ty: WasmHeapType
    ) -> WasmResult<Value> { ... }
    fn translate_ref_is_null(
        &mut self,
        pos: FuncCursor<'_>,
        value: Value
    ) -> WasmResult<Value> { ... }
    fn translate_loop_header(
        &mut self,
        _builder: &mut FunctionBuilder<'_>
    ) -> WasmResult<()> { ... }
    fn before_translate_operator(
        &mut self,
        _op: &Operator<'_>,
        _builder: &mut FunctionBuilder<'_>,
        _state: &FuncTranslationState
    ) -> WasmResult<()> { ... }
    fn after_translate_operator(
        &mut self,
        _op: &Operator<'_>,
        _builder: &mut FunctionBuilder<'_>,
        _state: &FuncTranslationState
    ) -> WasmResult<()> { ... }
    fn before_unconditionally_trapping_memory_access(
        &mut self,
        _builder: &mut FunctionBuilder<'_>
    ) -> WasmResult<()> { ... }
    fn before_translate_function(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _state: &FuncTranslationState
    ) -> WasmResult<()> { ... }
    fn after_translate_function(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _state: &FuncTranslationState
    ) -> WasmResult<()> { ... }
    fn relaxed_simd_deterministic(&self) -> bool { ... }
    fn has_native_fma(&self) -> bool { ... }
    fn is_x86(&self) -> bool { ... }
    fn use_x86_blendv_for_relaxed_laneselect(&self, ty: Type) -> bool { ... }
    fn use_x86_pshufb_for_relaxed_swizzle(&self) -> bool { ... }
    fn use_x86_pmulhrsw_for_relaxed_q15mul(&self) -> bool { ... }
    fn use_x86_pmaddubsw_for_dot(&self) -> bool { ... }
    fn handle_before_return(
        &mut self,
        _retvals: &[Value],
        _builder: &mut FunctionBuilder<'_>
    ) { ... }
    fn before_load(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _val_size: u8,
        _addr: Value,
        _offset: u64
    ) { ... }
    fn before_store(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _val_size: u8,
        _addr: Value,
        _offset: u64
    ) { ... }
    fn update_global(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _global_index: u32,
        _value: Value
    ) { ... }
    fn before_memory_grow(
        &mut self,
        _builder: &mut FunctionBuilder<'_>,
        _num_bytes: Value,
        _mem_index: MemoryIndex
    ) { ... }
}

Environment affecting the translation of a single WebAssembly function.

A FuncEnvironment trait object is required to translate a WebAssembly function to Cranelift IR. The function environment provides information about the WebAssembly module as well as the runtime environment.

Required Methods

fn make_global( &mut self, func: &mut Function, index: GlobalIndex ) -> WasmResult<GlobalVariable>

Set up the necessary preamble definitions in func to access the global variable identified by index.

The index space covers both imported globals and globals defined by the module.

Return the global variable reference that should be used to access the global and the WebAssembly type of the global.

fn heaps(&self) -> &PrimaryMap<Heap, HeapData>

Get the heaps for this function environment.

The returned map should provide heap format details (encoded in HeapData) for each Heap that was previously returned by make_heap(). The translator will first call make_heap for each Wasm memory, and then later when translating code, will invoke heaps() to learn how to access the environment’s implementation of each memory.

fn make_heap( &mut self, func: &mut Function, index: MemoryIndex ) -> WasmResult<Heap>

Set up the necessary preamble definitions in func to access the linear memory identified by index.

The index space covers both imported and locally declared memories.

fn make_indirect_sig( &mut self, func: &mut Function, index: TypeIndex ) -> WasmResult<SigRef>

Set up a signature definition in the preamble of func that can be used for an indirect call with signature index.

The signature may contain additional arguments needed for an indirect call, but the arguments marked as ArgumentPurpose::Normal must correspond to the WebAssembly signature arguments.

The signature will only be used for indirect calls, even if the module has direct function calls with the same WebAssembly type.

fn make_direct_func( &mut self, func: &mut Function, index: FuncIndex ) -> WasmResult<FuncRef>

Set up an external function definition in the preamble of func that can be used to directly call the function index.

The index space covers both imported functions and functions defined in the current module.

The function’s signature may contain additional arguments needed for a direct call, but the arguments marked as ArgumentPurpose::Normal must correspond to the WebAssembly signature arguments.

The function’s signature will only be used for direct calls, even if the module has indirect calls with the same WebAssembly type.

fn translate_call_indirect( &mut self, builder: &mut FunctionBuilder<'_>, table_index: TableIndex, sig_index: TypeIndex, sig_ref: SigRef, callee: Value, call_args: &[Value] ) -> WasmResult<Option<Inst>>

Translate a call_indirect WebAssembly instruction at pos.

Insert instructions at pos for an indirect call to the function callee in the table table_index with WebAssembly signature sig_index. The callee value will have type i32.

The signature sig_ref was previously created by make_indirect_sig().

Return the call instruction whose results are the WebAssembly return values. Returns None if this statically traps instead of creating a call instruction.

fn translate_return_call_indirect( &mut self, builder: &mut FunctionBuilder<'_>, table_index: TableIndex, sig_index: TypeIndex, sig_ref: SigRef, callee: Value, call_args: &[Value] ) -> WasmResult<()>

Translate a return_call_indirect WebAssembly instruction at the builder’s current position.

Insert instructions at the builder’s current position for an indirect tail call to the function callee in the table table_index with WebAssembly signature sig_index. The callee value will have type i32.

The signature sig_ref was previously created by make_indirect_sig().

fn translate_return_call_ref( &mut self, builder: &mut FunctionBuilder<'_>, sig_ref: SigRef, callee: Value, call_args: &[Value] ) -> WasmResult<()>

Translate a return_call_ref WebAssembly instruction at the builder’s given position.

Insert instructions at the builder’s current position for an indirect tail call to the function callee. The callee value will be a Wasm funcref that may need to be translated to a native function address depending on your implementation of this trait.

The signature sig_ref was previously created by make_indirect_sig().

fn translate_call_ref( &mut self, builder: &mut FunctionBuilder<'_>, sig_ref: SigRef, callee: Value, call_args: &[Value] ) -> WasmResult<Inst>

Translate a call_ref WebAssembly instruction at the builder’s current position.

Insert instructions at the builder’s current position for an indirect call to the function callee. The callee value will be a Wasm funcref that may need to be translated to a native function address depending on your implementation of this trait.

The signature sig_ref was previously created by make_indirect_sig().

Return the call instruction whose results are the WebAssembly return values.

fn translate_memory_grow( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap, val: Value ) -> WasmResult<Value>

Translate a memory.grow WebAssembly instruction.

The index provided identifies the linear memory to grow, and heap is the heap reference returned by make_heap for the same index.

The val value is the requested memory size in pages.

Returns the old size (in pages) of the memory.

fn translate_memory_size( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap ) -> WasmResult<Value>

Translates a memory.size WebAssembly instruction.

The index provided identifies the linear memory to query, and heap is the heap reference returned by make_heap for the same index.

Returns the size in pages of the memory.

fn translate_memory_copy( &mut self, pos: FuncCursor<'_>, src_index: MemoryIndex, src_heap: Heap, dst_index: MemoryIndex, dst_heap: Heap, dst: Value, src: Value, len: Value ) -> WasmResult<()>

Translate a memory.copy WebAssembly instruction.

The index provided identifies the linear memory to query, and heap is the heap reference returned by make_heap for the same index.

fn translate_memory_fill( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap, dst: Value, val: Value, len: Value ) -> WasmResult<()>

Translate a memory.fill WebAssembly instruction.

The index provided identifies the linear memory to query, and heap is the heap reference returned by make_heap for the same index.

fn translate_memory_init( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap, seg_index: u32, dst: Value, src: Value, len: Value ) -> WasmResult<()>

Translate a memory.init WebAssembly instruction.

The index provided identifies the linear memory to query, and heap is the heap reference returned by make_heap for the same index. seg_index is the index of the segment to copy from.

fn translate_data_drop( &mut self, pos: FuncCursor<'_>, seg_index: u32 ) -> WasmResult<()>

Translate a data.drop WebAssembly instruction.

fn translate_table_size( &mut self, pos: FuncCursor<'_>, index: TableIndex ) -> WasmResult<Value>

Translate a table.size WebAssembly instruction.

fn translate_table_grow( &mut self, pos: FuncCursor<'_>, table_index: TableIndex, delta: Value, init_value: Value ) -> WasmResult<Value>

Translate a table.grow WebAssembly instruction.

fn translate_table_get( &mut self, builder: &mut FunctionBuilder<'_>, table_index: TableIndex, index: Value ) -> WasmResult<Value>

Translate a table.get WebAssembly instruction.

fn translate_table_set( &mut self, builder: &mut FunctionBuilder<'_>, table_index: TableIndex, value: Value, index: Value ) -> WasmResult<()>

Translate a table.set WebAssembly instruction.

fn translate_table_copy( &mut self, pos: FuncCursor<'_>, dst_table_index: TableIndex, src_table_index: TableIndex, dst: Value, src: Value, len: Value ) -> WasmResult<()>

Translate a table.copy WebAssembly instruction.

fn translate_table_fill( &mut self, pos: FuncCursor<'_>, table_index: TableIndex, dst: Value, val: Value, len: Value ) -> WasmResult<()>

Translate a table.fill WebAssembly instruction.

fn translate_table_init( &mut self, pos: FuncCursor<'_>, seg_index: u32, table_index: TableIndex, dst: Value, src: Value, len: Value ) -> WasmResult<()>

Translate a table.init WebAssembly instruction.

fn translate_elem_drop( &mut self, pos: FuncCursor<'_>, seg_index: u32 ) -> WasmResult<()>

Translate a elem.drop WebAssembly instruction.

fn translate_ref_func( &mut self, pos: FuncCursor<'_>, func_index: FuncIndex ) -> WasmResult<Value>

Translate a ref.func WebAssembly instruction.

fn translate_custom_global_get( &mut self, pos: FuncCursor<'_>, global_index: GlobalIndex ) -> WasmResult<Value>

Translate a global.get WebAssembly instruction at pos for a global that is custom.

fn translate_custom_global_set( &mut self, pos: FuncCursor<'_>, global_index: GlobalIndex, val: Value ) -> WasmResult<()>

Translate a global.set WebAssembly instruction at pos for a global that is custom.

fn translate_atomic_wait( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap, addr: Value, expected: Value, timeout: Value ) -> WasmResult<Value>

Translate an i32.atomic.wait or i64.atomic.wait WebAssembly instruction. The index provided identifies the linear memory containing the value to wait on, and heap is the heap reference returned by make_heap for the same index. Whether the waited-on value is 32- or 64-bit can be determined by examining the type of expected, which must be only I32 or I64.

Note that the addr here is the host linear memory address rather than a relative wasm linear memory address. The type of this value is the same as the host’s pointer.

Returns an i32, which is negative if the helper call failed.

fn translate_atomic_notify( &mut self, pos: FuncCursor<'_>, index: MemoryIndex, heap: Heap, addr: Value, count: Value ) -> WasmResult<Value>

Translate an atomic.notify WebAssembly instruction. The index provided identifies the linear memory containing the value to wait on, and heap is the heap reference returned by make_heap for the same index.

Note that the addr here is the host linear memory address rather than a relative wasm linear memory address. The type of this value is the same as the host’s pointer.

Returns an i64, which is negative if the helper call failed.

fn translate_ref_i31( &mut self, pos: FuncCursor<'_>, val: Value ) -> WasmResult<Value>

Translate an i32 value into an i31ref.

fn translate_i31_get_s( &mut self, pos: FuncCursor<'_>, i31ref: Value ) -> WasmResult<Value>

Sign-extend an i31ref into an i32.

fn translate_i31_get_u( &mut self, pos: FuncCursor<'_>, i31ref: Value ) -> WasmResult<Value>

Zero-extend an i31ref into an i32.

Provided Methods

fn is_wasm_parameter(&self, signature: &Signature, index: usize) -> bool

Is the given parameter of the given function a wasm-level parameter, as opposed to a hidden parameter added for use by the implementation?

fn is_wasm_return(&self, signature: &Signature, index: usize) -> bool

Is the given return of the given function a wasm-level parameter, as opposed to a hidden parameter added for use by the implementation?

fn after_locals(&mut self, num_locals_defined: usize)

Called after the locals for a function have been parsed, and the number of variables defined by this function is provided.

fn translate_call( &mut self, builder: &mut FunctionBuilder<'_>, _callee_index: FuncIndex, callee: FuncRef, call_args: &[Value] ) -> WasmResult<Inst>

Translate a call WebAssembly instruction at pos.

Insert instructions at pos for a direct call to the function callee_index.

The function reference callee was previously created by make_direct_func().

Return the call instruction whose results are the WebAssembly return values.

fn translate_return_call( &mut self, builder: &mut FunctionBuilder<'_>, _callee_index: FuncIndex, callee: FuncRef, call_args: &[Value] ) -> WasmResult<()>

Translate a return_call WebAssembly instruction at the builder’s current position.

Insert instructions at the builder’s current position for a direct tail call to the function callee_index.

The function reference callee was previously created by make_direct_func().

Return the call instruction whose results are the WebAssembly return values.

fn translate_ref_null( &mut self, pos: FuncCursor<'_>, ty: WasmHeapType ) -> WasmResult<Value>

Translate a ref.null T WebAssembly instruction.

By default, translates into a null reference type.

Override this if you don’t use Cranelift reference types for all Wasm reference types (e.g. you use a raw pointer for funcrefs) or if the null sentinel is not a null reference type pointer for your type. If you override this method, then you should also override translate_ref_is_null as well.

fn translate_ref_is_null( &mut self, pos: FuncCursor<'_>, value: Value ) -> WasmResult<Value>

Translate a ref.is_null WebAssembly instruction.

By default, assumes that value is a Cranelift reference type, and that a null Cranelift reference type is the null value for all Wasm reference types.

If you override this method, you probably also want to override translate_ref_null as well.

fn translate_loop_header( &mut self, _builder: &mut FunctionBuilder<'_> ) -> WasmResult<()>

Emit code at the beginning of every wasm loop.

This can be used to insert explicit interrupt or safepoint checking at the beginnings of loops.

fn before_translate_operator( &mut self, _op: &Operator<'_>, _builder: &mut FunctionBuilder<'_>, _state: &FuncTranslationState ) -> WasmResult<()>

Optional callback for the FunctionEnvironment performing this translation to maintain internal state or prepare custom state for the operator to translate

fn after_translate_operator( &mut self, _op: &Operator<'_>, _builder: &mut FunctionBuilder<'_>, _state: &FuncTranslationState ) -> WasmResult<()>

Optional callback for the FunctionEnvironment performing this translation to maintain internal state or finalize custom state for the operator that was translated

fn before_unconditionally_trapping_memory_access( &mut self, _builder: &mut FunctionBuilder<'_> ) -> WasmResult<()>

Optional callback for the FuncEnvironment performing this translation to maintain, prepare, or finalize custom, internal state when we statically determine that a Wasm memory access will unconditionally trap, rendering the rest of the block unreachable. Called just before the unconditional trap is emitted.

fn before_translate_function( &mut self, _builder: &mut FunctionBuilder<'_>, _state: &FuncTranslationState ) -> WasmResult<()>

Optional callback for the FunctionEnvironment performing this translation to perform work before the function body is translated.

fn after_translate_function( &mut self, _builder: &mut FunctionBuilder<'_>, _state: &FuncTranslationState ) -> WasmResult<()>

Optional callback for the FunctionEnvironment performing this translation to perform work after the function body is translated.

fn relaxed_simd_deterministic(&self) -> bool

Whether or not to force relaxed simd instructions to have deterministic lowerings meaning they will produce the same results across all hosts, regardless of the cost to performance.

fn has_native_fma(&self) -> bool

Whether or not the target being translated for has a native fma instruction. If it does not then when relaxed simd isn’t deterministic the translation of the f32x4.relaxed_fma instruction, for example, will do a multiplication and then an add instead of the fused version.

fn is_x86(&self) -> bool

Returns whether this is an x86 target, which may alter lowerings of relaxed simd instructions.

fn use_x86_blendv_for_relaxed_laneselect(&self, ty: Type) -> bool

Returns whether the CLIF x86_blendv instruction should be used for the relaxed simd *.relaxed_laneselect instruction for the specified type.

fn use_x86_pshufb_for_relaxed_swizzle(&self) -> bool

Returns whether the CLIF x86_pshufb instruction should be used for the i8x16.relaxed_swizzle instruction.

fn use_x86_pmulhrsw_for_relaxed_q15mul(&self) -> bool

Returns whether the CLIF x86_pmulhrsw instruction should be used for the i8x16.relaxed_q15mulr_s instruction.

fn use_x86_pmaddubsw_for_dot(&self) -> bool

Returns whether the CLIF x86_pmaddubsw instruction should be used for the relaxed-simd dot-product instructions instruction.

fn handle_before_return( &mut self, _retvals: &[Value], _builder: &mut FunctionBuilder<'_> )

Inserts code before a function return.

fn before_load( &mut self, _builder: &mut FunctionBuilder<'_>, _val_size: u8, _addr: Value, _offset: u64 )

Inserts code before a load.

fn before_store( &mut self, _builder: &mut FunctionBuilder<'_>, _val_size: u8, _addr: Value, _offset: u64 )

Inserts code before a store.

fn update_global( &mut self, _builder: &mut FunctionBuilder<'_>, _global_index: u32, _value: Value )

Inserts code before updating a global.

fn before_memory_grow( &mut self, _builder: &mut FunctionBuilder<'_>, _num_bytes: Value, _mem_index: MemoryIndex )

Inserts code before memory.grow.

Implementors