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/**
* \file wasmtime/val.h
*
* APIs for interacting with WebAssembly values in Wasmtime.
*/
#ifndef WASMTIME_VAL_H
#define WASMTIME_VAL_H
#include <wasm.h>
#include <wasmtime/extern.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* \typedef wasmtime_externref_t
* \brief Convenience alias for #wasmtime_externref
*
* \struct wasmtime_externref
* \brief A host-defined un-forgeable reference to pass into WebAssembly.
*
* This structure represents an `externref` that can be passed to WebAssembly.
* It cannot be forged by WebAssembly itself and is guaranteed to have been
* created by the host.
*/
typedef struct wasmtime_externref wasmtime_externref_t;
/**
* \brief Create a new `externref` value.
*
* Creates a new `externref` value wrapping the provided data, returning the
* pointer to the externref.
*
* \param data the host-specific data to wrap
* \param 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
*/
WASM_API_EXTERN wasmtime_externref_t *
wasmtime_externref_new(void *data, void (*finalizer)(void *));
/**
* \brief Get an `externref`'s wrapped data
*
* Returns the original `data` passed to #wasmtime_externref_new. It is required
* that `data` is not `NULL`.
*/
WASM_API_EXTERN void *wasmtime_externref_data(wasmtime_externref_t *data);
/**
* \brief Creates a shallow copy of the `externref` argument, returning a
* separately owned pointer (increases the reference count).
*/
WASM_API_EXTERN wasmtime_externref_t *
wasmtime_externref_clone(wasmtime_externref_t *ref);
/**
* \brief Decrements the reference count of the `ref`, deleting it if it's the
* last reference.
*/
WASM_API_EXTERN void wasmtime_externref_delete(wasmtime_externref_t *ref);
/**
* \brief 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.
*/
WASM_API_EXTERN wasmtime_externref_t *
wasmtime_externref_from_raw(wasmtime_context_t *context, void *raw);
/**
* \brief 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.
*/
WASM_API_EXTERN void *
wasmtime_externref_to_raw(wasmtime_context_t *context,
const wasmtime_externref_t *ref);
/// \brief Discriminant stored in #wasmtime_val::kind
typedef uint8_t wasmtime_valkind_t;
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is an i32
#define WASMTIME_I32 0
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is an i64
#define WASMTIME_I64 1
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is a f32
#define WASMTIME_F32 2
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is a f64
#define WASMTIME_F64 3
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is a v128
#define WASMTIME_V128 4
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is a
/// funcref
#define WASMTIME_FUNCREF 5
/// \brief Value of #wasmtime_valkind_t meaning that #wasmtime_val_t is an
/// externref
#define WASMTIME_EXTERNREF 6
/// \brief A 128-bit value representing the WebAssembly `v128` type. Bytes are
/// stored in little-endian order.
typedef uint8_t wasmtime_v128[16];
/**
* \typedef wasmtime_valunion_t
* \brief Convenience alias for #wasmtime_valunion
*
* \union wasmtime_valunion
* \brief Container for different kinds of wasm values.
*
* This type is contained in #wasmtime_val_t and contains the payload for the
* various kinds of items a value can be.
*/
typedef union wasmtime_valunion {
/// Field used if #wasmtime_val_t::kind is #WASMTIME_I32
int32_t i32;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_I64
int64_t i64;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_F32
float32_t f32;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_F64
float64_t f64;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_FUNCREF
///
/// If this value represents a `ref.null func` value then the `store_id` field
/// is set to zero.
wasmtime_func_t funcref;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_EXTERNREF
///
/// If this value represents a `ref.null extern` value then this pointer will
/// be `NULL`.
wasmtime_externref_t *externref;
/// Field used if #wasmtime_val_t::kind is #WASMTIME_V128
wasmtime_v128 v128;
} wasmtime_valunion_t;
/**
* \typedef wasmtime_val_raw_t
* \brief Convenience alias for #wasmtime_val_raw
*
* \union wasmtime_val_raw
* \brief Container for possible wasm values.
*
* This type is used on conjunction with #wasmtime_func_new_unchecked as well
* as #wasmtime_func_call_unchecked. Instances of this type do not have type
* information associated with them, it's up to the embedder to figure out
* how to interpret the bits contained within, often using some other channel
* to determine the type.
*/
typedef union wasmtime_val_raw {
/// Field for when this val is a WebAssembly `i32` value.
///
/// Note that this field is always stored in a little-endian format.
int32_t i32;
/// Field for when this val is a WebAssembly `i64` value.
///
/// Note that this field is always stored in a little-endian format.
int64_t i64;
/// Field for when this val is a WebAssembly `f32` value.
///
/// Note that this field is always stored in a little-endian format.
float32_t f32;
/// Field for when this val is a WebAssembly `f64` value.
///
/// Note that this field is always stored in a little-endian format.
float64_t f64;
/// Field for when this val is a WebAssembly `v128` value.
///
/// Note that this field is always stored in a little-endian format.
wasmtime_v128 v128;
/// Field for when this val is a WebAssembly `funcref` value.
///
/// If this is set to 0 then it's a null funcref, otherwise this must be
/// passed to `wasmtime_func_from_raw` to determine the `wasmtime_func_t`.
///
/// Note that this field is always stored in a little-endian format.
void *funcref;
/// Field for when this val is a WebAssembly `externref` value.
///
/// If this is set to 0 then it's a null externref, otherwise this must be
/// passed to `wasmtime_externref_from_raw` to determine the
/// `wasmtime_externref_t`.
///
/// Note that this field is always stored in a little-endian format.
void *externref;
} wasmtime_val_raw_t;
/**
* \typedef wasmtime_val_t
* \brief Convenience alias for #wasmtime_val_t
*
* \union wasmtime_val
* \brief Container for different kinds of wasm values.
*
* Note that this structure may contain an owned value, namely
* #wasmtime_externref_t, depending on the context in which this is used. APIs
* which consume a #wasmtime_val_t do not take ownership, but APIs that return
* #wasmtime_val_t require that #wasmtime_val_delete is called to deallocate
* the value.
*/
typedef struct wasmtime_val {
/// Discriminant of which field of #of is valid.
wasmtime_valkind_t kind;
/// Container for the extern item's value.
wasmtime_valunion_t of;
} wasmtime_val_t;
/**
* \brief 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).
*/
WASM_API_EXTERN void wasmtime_val_delete(wasmtime_val_t *val);
/**
* \brief Copies `src` into `dst`.
*/
WASM_API_EXTERN void wasmtime_val_copy(wasmtime_val_t *dst,
const wasmtime_val_t *src);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // WASMTIME_VAL_H