Struct wit_parser::Resolve

pub struct Resolve {
    pub worlds: Arena<World>,
    pub interfaces: Arena<Interface>,
    pub types: Arena<TypeDef>,
    pub packages: Arena<Package>,
    pub package_names: IndexMap<PackageName, PackageId>,
}

Representation of a fully resolved set of WIT packages.

This structure contains a graph of WIT packages and all of their contents merged together into the contained arenas. All items are sorted topologically and everything here is fully resolved, so with a Resolve no name lookups are necessary and instead everything is index-based.

Working with a WIT package requires inserting it into a Resolve to ensure that all of its dependencies are satisfied. This will give the full picture of that package’s types and such.

Each item in a Resolve has a parent link to trace it back to the original package as necessary.

Fields

worlds: Arena<World>

interfaces: Arena<Interface>

types: Arena<TypeDef>

packages: Arena<Package>

package_names: IndexMap<PackageName, PackageId>

Implementations

impl Resolve

pub fn wasm_signature( &self, variant: AbiVariant, func: &Function ) -> WasmSignature

Get the WebAssembly type signature for this interface function

The first entry returned is the list of parameters and the second entry is the list of results for the wasm function signature.

pub fn call( &self, variant: AbiVariant, lift_lower: LiftLower, func: &Function, bindgen: &mut impl Bindgen )

Generates an abstract sequence of instructions which represents this function being adapted as an imported function.

The instructions here, when executed, will emulate a language with interface types calling the concrete wasm implementation. The parameters for the returned instruction sequence are the language’s own interface-types parameters. One instruction in the instruction stream will be a Call which represents calling the actual raw wasm function signature.

This function is useful, for example, if you’re building a language generator for WASI bindings. This will document how to translate language-specific values into the wasm types to call a WASI function, and it will also automatically convert the results of the WASI function back to a language-specific value.

pub fn guest_export_needs_post_return(&self, func: &Function) -> bool

Returns whether the Function specified needs a post-return function to be generated in guest code.

This is used when the return value contains a memory allocation such as a list or a string primarily.

pub fn post_return(&self, func: &Function, bindgen: &mut impl Bindgen)

Used in a similar manner as the Interface::call function except is used to generate the post-return callback for func.

This is only intended to be used in guest generators for exported functions and will primarily generate GuestDeallocate* instructions, plus others used as input to those instructions.

impl Resolve

pub fn new() -> Resolve

Creates a new Resolve with no packages/items inside of it.

pub fn push_dir(&mut self, path: &Path) -> Result<(PackageId, Vec<PathBuf>)>

Parses the filesystem directory at path as a WIT package and returns the fully resolved PackageId as a result.

Dependencies referenced by the WIT package at path will be loaded from a deps/.. directory under path. All directories under deps/ will be parsed as a WIT package. The directory name containing each package is not used as each package is otherwise self-identifying.

This function returns the PackageId of the root parsed package at path, along with a list of all paths that were consumed during parsing for the root package and all dependency packages.

pub fn push(&mut self, unresolved: UnresolvedPackage) -> Result<PackageId>

Appends a new UnresolvedPackage to this Resolve, creating a fully resolved package with no dangling references.

The deps argument indicates that the named dependencies in unresolved to packages are resolved by the mapping specified.

Any dependency resolution error or otherwise world-elaboration error will be returned here. If successful a package identifier is returned.

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

pub fn merge(&mut self, resolve: Resolve) -> Result<Remap>

Merges all the contents of a different Resolve into this one. The Remap structure returned provides a mapping from all old indices to new indices

This operation can fail if resolve disagrees with self about the packages being inserted. Otherwise though this will additionally attempt to “union” packages found in resolve with those found in self. Unioning packages is keyed on the name/url of packages for those with URLs present. If found then it’s assumed that both Resolve instances were originally created from the same contents and are two views of the same package.

pub fn merge_worlds(&mut self, from: WorldId, into: WorldId) -> Result<()>

Merges the world from into the world into.

This will attempt to merge one world into another, unioning all of its imports and exports together. This is an operation performed by wit-component, for example where two different worlds from two different libraries were linked into the same core wasm file and are producing a singular world that will be the final component’s interface.

This operation can fail if the imports/exports overlap.

pub fn id_of(&self, interface: InterfaceId) -> Option<String>

Returns the ID of the specified interface.

Returns None for unnamed interfaces.

pub fn select_world( &self, pkg: PackageId, world: Option<&str> ) -> Result<WorldId>

Attempts to locate a world given the “default” package pkg and the optional string specifier world.

This method is intended to be used by bindings generation tools to select a world from either pkg or a package in this Resolve.

If world is None then pkg must have precisely one world which will be returned.

If world is Some then it can either be:

• A kebab-name of a world contained within pkg which is being selected, such as "the-world".

• An ID-based form of a world which is selected within this Resolve, ignoring pkg. For example "wasi:http/proxy".

If successful the corresponding WorldId is returned, otherwise an error is returned.

pub fn name_world_key(&self, key: &WorldKey) -> String

Assigns a human readable name to the WorldKey specified.

pub fn interface_direct_deps( &self, id: InterfaceId ) -> impl Iterator<Item = InterfaceId> + '_

Returns an iterator of all interfaces that the interface id depends on.

Interfaces may depend on others for type information to resolve type imports.

Note that the returned iterate may yield the same interface as a dependency multiple times. Additionally only direct dependencies of id are yielded, not transitive dependencies.

Trait Implementations

impl Clone for Resolve

fn clone(&self) -> Resolve

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Default for Resolve

fn default() -> Resolve

Returns the “default value” for a type.