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/**
* \file wasi.h
*
* C API for WASI
*/
#ifndef WASI_H
#define WASI_H
#include "wasm.h"
#ifndef WASI_API_EXTERN
#ifdef _WIN32
#define WASI_API_EXTERN __declspec(dllimport)
#else
#define WASI_API_EXTERN
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
#define own
#define WASI_DECLARE_OWN(name) \
typedef struct wasi_##name##_t wasi_##name##_t; \
WASI_API_EXTERN void wasi_##name##_delete(own wasi_##name##_t*);
/**
* \typedef wasi_config_t
* \brief Convenience alias for #wasi_config_t
*
* \struct wasi_config_t
* \brief Opaque type used to create a #wasi_instance_t.
*
* \fn void wasi_config_delete(own wasi_config_t *);
* \brief Deletes a configuration object.
*/
WASI_DECLARE_OWN(config)
/**
* \brief Creates a new empty configuration object.
*
* The caller is expected to deallocate the returned configuration
*/
WASI_API_EXTERN own wasi_config_t* wasi_config_new();
/**
* \brief Sets the argv list for this configuration object.
*
* By default WASI programs have an empty argv list, but this can be used to
* explicitly specify what the argv list for the program is.
*
* The arguments are copied into the `config` object as part of this function
* call, so the `argv` pointer only needs to stay alive for this function call.
*/
WASI_API_EXTERN void wasi_config_set_argv(wasi_config_t* config, int argc, const char* argv[]);
/**
* \brief Indicates that the argv list should be inherited from this process's
* argv list.
*/
WASI_API_EXTERN void wasi_config_inherit_argv(wasi_config_t* config);
/**
* \brief Sets the list of environment variables available to the WASI instance.
*
* By default WASI programs have a blank environment, but this can be used to
* define some environment variables for them.
*
* It is required that the `names` and `values` lists both have `envc` entries.
*
* The env vars are copied into the `config` object as part of this function
* call, so the `names` and `values` pointers only need to stay alive for this
* function call.
*/
WASI_API_EXTERN void wasi_config_set_env(wasi_config_t* config, int envc, const char* names[], const char* values[]);
/**
* \brief Indicates that the entire environment of the calling process should be
* inherited by this WASI configuration.
*/
WASI_API_EXTERN void wasi_config_inherit_env(wasi_config_t* config);
/**
* \brief Configures standard input to be taken from the specified file.
*
* By default WASI programs have no stdin, but this configures the specified
* file to be used as stdin for this configuration.
*
* If the stdin location does not exist or it cannot be opened for reading then
* `false` is returned. Otherwise `true` is returned.
*/
WASI_API_EXTERN bool wasi_config_set_stdin_file(wasi_config_t* config, const char* path);
/**
* \brief Configures this process's own stdin stream to be used as stdin for
* this WASI configuration.
*/
WASI_API_EXTERN void wasi_config_inherit_stdin(wasi_config_t* config);
/**
* \brief Configures standard output to be written to the specified file.
*
* By default WASI programs have no stdout, but this configures the specified
* file to be used as stdout.
*
* If the stdout location could not be opened for writing then `false` is
* returned. Otherwise `true` is returned.
*/
WASI_API_EXTERN bool wasi_config_set_stdout_file(wasi_config_t* config, const char* path);
/**
* \brief Configures this process's own stdout stream to be used as stdout for
* this WASI configuration.
*/
WASI_API_EXTERN void wasi_config_inherit_stdout(wasi_config_t* config);
/**
* \brief Configures standard output to be written to the specified file.
*
* By default WASI programs have no stderr, but this configures the specified
* file to be used as stderr.
*
* If the stderr location could not be opened for writing then `false` is
* returned. Otherwise `true` is returned.
*/
WASI_API_EXTERN bool wasi_config_set_stderr_file(wasi_config_t* config, const char* path);
/**
* \brief Configures this process's own stderr stream to be used as stderr for
* this WASI configuration.
*/
WASI_API_EXTERN void wasi_config_inherit_stderr(wasi_config_t* config);
/**
* \brief Configures a "preopened directory" to be available to WASI APIs.
*
* By default WASI programs do not have access to anything on the filesystem.
* This API can be used to grant WASI programs access to a directory on the
* filesystem, but only that directory (its whole contents but nothing above it).
*
* The `path` argument here is a path name on the host filesystem, and
* `guest_path` is the name by which it will be known in wasm.
*/
WASI_API_EXTERN bool wasi_config_preopen_dir(wasi_config_t* config, const char* path, const char* guest_path);
/**
* \typedef wasi_instance_t
* \brief Convenience alias for #wasi_instance_t
*
* \struct wasi_instance_t
* \brief Opaque type representing a WASI instance.
*
* \fn void wasi_instance_delete(own wasi_instance_t *);
* \brief Deletes an instance object.
*/
WASI_DECLARE_OWN(instance)
/**
* \brief Creates a new WASI instance from the specified configuration.
*
* \param store the store which functions will be attached to
* \param name the WASI module name that is being instantiated, currently either
* `wasi_unstable` or `wasi_snapshot_preview`.
* \param config the configuration object which has settings for how WASI APIs
* will behave.
* \param trap a location, if `NULL` is returned, that contains information
* about why instantiation failed.
*
* \return a #wasi_instance_t owned by the caller on success or `NULL` on
* failure.
*
* Note that this function takes ownership of the `config` argument whether this
* function succeeds or not. Ownership of the #wasi_instance_t and #wasm_trap_t
* are transferred to the caller.
*
* With a #wasi_instance_t you'll likely call either
* #wasmtime_linker_define_wasi or #wasi_instance_bind_import afterwards.
*/
WASI_API_EXTERN own wasi_instance_t* wasi_instance_new(
wasm_store_t* store,
const char* name,
own wasi_config_t* config,
own wasm_trap_t** trap
);
/**
* \brief Extracts a matching item for the given import from a #wasi_instance_t.
*
* \param instance the WASI instance an export is extracted from
* \param import the desired import type that is being extracted, typically
* acquired from #wasm_module_imports.
*
* \return a #wasm_extern_t which can be used to satisfy the `import`
* requested, or `NULL` if the provided `instance` cannot satisfy `import`.
*
* This function does not take ownership of its arguments, and the lifetime of
* the #wasm_extern_t is tied to the #wasi_instance_t argument.
*/
WASI_API_EXTERN const wasm_extern_t* wasi_instance_bind_import(
const wasi_instance_t* instance,
const wasm_importtype_t* import
);
#undef own
#ifdef __cplusplus
} // extern "C"
#endif
#endif // #ifdef WASI_H