val.h File Reference

#include <stdalign.h>
#include <wasm.h>
#include <wasmtime/extern.h>

Go to the source code of this file.

Data Structures
union	wasmtime_valunion
	Container for different kinds of wasm values. More...
union	wasmtime_val_raw
	Container for possible wasm values. More...
union	wasmtime_val
	Container for different kinds of wasm values. More...

Macros
#define	WASMTIME_I32   0
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is an i32.
#define	WASMTIME_I64   1
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is an i64.
#define	WASMTIME_F32   2
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is a f32.
#define	WASMTIME_F64   3
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is a f64.
#define	WASMTIME_V128   4
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is a v128.
#define	WASMTIME_FUNCREF   5
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is a funcref.
#define	WASMTIME_EXTERNREF   6
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is an externref.
#define	WASMTIME_ANYREF   7
	Value of wasmtime_valkind_t meaning that wasmtime_val_t is an anyref.

Typedefs
typedef struct wasmtime_anyref	wasmtime_anyref_t
	Convenience alias for wasmtime_anyref.
typedef struct wasmtime_externref	wasmtime_externref_t
	Convenience alias for wasmtime_externref.
typedef uint8_t	wasmtime_valkind_t
	Discriminant stored in wasmtime_val::kind.
typedef uint8_t	wasmtime_v128[16]
	A 128-bit value representing the WebAssembly v128 type. Bytes are stored in little-endian order.
typedef union wasmtime_valunion	wasmtime_valunion_t
	Convenience alias for wasmtime_valunion.
typedef union wasmtime_val_raw	wasmtime_val_raw_t
	Convenience alias for wasmtime_val_raw.
typedef struct wasmtime_val	wasmtime_val_t
	Convenience alias for wasmtime_val_t.

Functions
wasmtime_anyref_t *	wasmtime_anyref_clone (wasmtime_context_t *context, wasmtime_anyref_t *ref)
	Creates a shallow copy of the anyref argument, returning a separately owned pointer (depending on the configured collector this might increase a reference count or create a new GC root).
void	wasmtime_anyref_delete (wasmtime_context_t *context, wasmtime_anyref_t *ref)
	Drops an owned pointer to ref, potentially deleting it if it's the last reference, or allowing it to be collected during the next GC.
wasmtime_anyref_t *	wasmtime_anyref_from_raw (wasmtime_context_t *context, uint32_t raw)
	Converts a raw anyref value coming from wasmtime_val_raw_t into a wasmtime_anyref_t. More...
uint32_t	wasmtime_anyref_to_raw (wasmtime_context_t *context, const wasmtime_anyref_t *ref)
	Converts a wasmtime_anyref_t to a raw value suitable for storing into a wasmtime_val_raw_t. More...
wasmtime_anyref_t *	wasmtime_anyref_from_i31 (wasmtime_context_t *context, uint32_t i31val)
	Create a new i31ref value. More...
bool	wasmtime_anyref_i31_get_u (wasmtime_context_t *context, wasmtime_anyref_t *anyref, uint32_t *dst)
	Get the anyref's underlying i31ref value, zero extended, if any. More...
bool	wasmtime_anyref_i31_get_s (wasmtime_context_t *context, wasmtime_anyref_t *anyref, int32_t *dst)
	Get the anyref's underlying i31ref value, sign extended, if any. More...
wasmtime_externref_t *	wasmtime_externref_new (wasmtime_context_t *context, void *data, void(*finalizer)(void *))
	Create a new externref value. More...
void *	wasmtime_externref_data (wasmtime_context_t *context, wasmtime_externref_t *data)
	Get an externref's wrapped data. More...
wasmtime_externref_t *	wasmtime_externref_clone (wasmtime_context_t *context, wasmtime_externref_t *ref)
	Creates a shallow copy of the externref argument, returning a separately owned pointer (depending on the configured collector this might increase a reference count or create a new GC root).
void	wasmtime_externref_delete (wasmtime_context_t *context, wasmtime_externref_t *ref)
	Drops an owned pointer to ref, potentially deleting it if it's the last reference, or allowing it to be collected during the next GC.
wasmtime_externref_t *	wasmtime_externref_from_raw (wasmtime_context_t *context, uint32_t raw)
	Converts a raw externref value coming from wasmtime_val_raw_t into a wasmtime_externref_t. More...
uint32_t	wasmtime_externref_to_raw (wasmtime_context_t *context, const wasmtime_externref_t *ref)
	Converts a wasmtime_externref_t to a raw value suitable for storing into a wasmtime_val_raw_t. More...
void	wasmtime_val_delete (wasmtime_context_t *context, wasmtime_val_t *val)
	Deletes an owned wasmtime_val_t. More...
void	wasmtime_val_copy (wasmtime_context_t *context, wasmtime_val_t *dst, const wasmtime_val_t *src)
	Copies src into dst.

Detailed Description

APIs for interacting with WebAssembly values in Wasmtime.

Function Documentation

wasmtime_anyref_from_i31()

wasmtime_anyref_t * wasmtime_anyref_from_i31	(	wasmtime_context_t *	context,
		uint32_t	i31val
	)

Create a new i31ref value.

Creates a new i31ref value (which is a subtype of anyref) and returns a pointer to it.

If i31val does not fit in 31 bits, it is wrapped.

wasmtime_anyref_from_raw()

wasmtime_anyref_t * wasmtime_anyref_from_raw	(	wasmtime_context_t *	context,
		uint32_t	raw
	)

Converts a raw anyref value coming from wasmtime_val_raw_t into a wasmtime_anyref_t.

Note that the returned wasmtime_anyref_t is an owned value that must be deleted via wasmtime_anyref_delete by the caller if it is non-null.

wasmtime_anyref_i31_get_s()

bool wasmtime_anyref_i31_get_s	(	wasmtime_context_t *	context,
		wasmtime_anyref_t *	anyref,
		int32_t *	dst
	)

Get the anyref's underlying i31ref value, sign extended, if any.

If the given anyref is an instance of i31ref, then its value is sign extended to 32 bits, written to dst, and true is returned.

If the given anyref is not an instance of i31ref, then false is returned and dst is left unmodified.

wasmtime_anyref_i31_get_u()

bool wasmtime_anyref_i31_get_u	(	wasmtime_context_t *	context,
		wasmtime_anyref_t *	anyref,
		uint32_t *	dst
	)

Get the anyref's underlying i31ref value, zero extended, if any.

If the given anyref is an instance of i31ref, then its value is zero extended to 32 bits, written to dst, and true is returned.

If the given anyref is not an instance of i31ref, then false is returned and dst is left unmodified.

wasmtime_anyref_to_raw()

uint32_t wasmtime_anyref_to_raw	(	wasmtime_context_t *	context,
		const wasmtime_anyref_t *	ref
	)

Converts a wasmtime_anyref_t to a raw value suitable for storing into a wasmtime_val_raw_t.

Note that the returned underlying value is not tracked by Wasmtime's garbage collector until it enters WebAssembly. This means that a GC may release the context's reference to the raw value, making the raw value invalid within the context of the store. Do not perform a GC between calling this function and passing it to WebAssembly.

wasmtime_externref_data()

void * wasmtime_externref_data	(	wasmtime_context_t *	context,
		wasmtime_externref_t *	data
	)

Get an externref's wrapped data.

Returns the original data passed to wasmtime_externref_new. It is required that data is not NULL.

wasmtime_externref_from_raw()

wasmtime_externref_t * wasmtime_externref_from_raw	(	wasmtime_context_t *	context,
		uint32_t	raw
	)

Converts a raw externref value coming from wasmtime_val_raw_t into a wasmtime_externref_t.

Note that the returned wasmtime_externref_t is an owned value that must be deleted via wasmtime_externref_delete by the caller if it is non-null.

wasmtime_externref_new()

wasmtime_externref_t * wasmtime_externref_new	(	wasmtime_context_t *	context,
		void *	data,
		void(*)(void *)	finalizer
	)

Create a new externref value.

Creates a new externref value wrapping the provided data, returning the pointer to the externref.

Parameters

context	the store context to allocate this externref within
data	the host-specific data to wrap
finalizer	an optional finalizer for data

When the reference is reclaimed, the wrapped data is cleaned up with the provided finalizer.

The returned value must be deleted with wasmtime_externref_delete and may not be used after the context is destroyed.

wasmtime_externref_to_raw()

uint32_t wasmtime_externref_to_raw	(	wasmtime_context_t *	context,
		const wasmtime_externref_t *	ref
	)

Converts a wasmtime_externref_t to a raw value suitable for storing into a wasmtime_val_raw_t.

Note that the returned underlying value is not tracked by Wasmtime's garbage collector until it enters WebAssembly. This means that a GC may release the context's reference to the raw value, making the raw value invalid within the context of the store. Do not perform a GC between calling this function and passing it to WebAssembly.

wasmtime_val_delete()

void wasmtime_val_delete	(	wasmtime_context_t *	context,
		wasmtime_val_t *	val
	)

Deletes an owned wasmtime_val_t.

Note that this only deletes the contents, not the memory that val points to itself (which is owned by the caller).