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Notes/notes-service/vendor/wasm-bindgen-macro-support/src/ast.rs
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2026-08-01 16:11:49 +03:00

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26 KiB
Rust

//! A representation of the Abstract Syntax Tree of a Rust program,
//! with all the added metadata necessary to generate Wasm bindings
//! for it.
use crate::{hash::ShortHash, Diagnostic};
use proc_macro2::{Ident, Span};
use std::hash::{Hash, Hasher};
use syn::Path;
use wasm_bindgen_shared as shared;
pub fn use_js_sys_futures() -> bool {
// Honor either the build-time cfg or an expansion-time environment variable.
// The env-var form is necessary because `cfg!(...)` is resolved when this
// proc-macro crate is itself compiled (on the host), and Cargo does not pass
// `--cfg`/`RUSTFLAGS` to host proc-macros when `--target` is used. Reading
// an env var at expansion time provides a stable workflow that works
// regardless of how the consumer configures Cargo.
cfg!(wasm_bindgen_use_js_sys) || std::env::var_os("WASM_BINDGEN_USE_JS_SYS").is_some()
}
/// Whether a function is a start function, and if so, whether it
/// should be exported to JS.
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum StartKind {
None,
Public,
Private,
}
impl StartKind {
pub fn is_start(self) -> bool {
matches!(self, StartKind::Public | StartKind::Private)
}
}
/// An abstract syntax tree representing a rust program. Contains
/// extra information for joining up this rust code with javascript.
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct Program {
/// rust -> js interfaces
pub exports: Vec<Export>,
/// js -> rust interfaces
pub imports: Vec<Import>,
/// linked-to modules
pub linked_modules: Vec<ImportModule>,
/// rust enums
pub enums: Vec<Enum>,
/// rust structs
pub structs: Vec<Struct>,
/// custom typescript sections to be included in the definition file
pub typescript_custom_sections: Vec<LitOrExpr>,
/// Inline JS snippets
pub inline_js: Vec<String>,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Path to js_sys
pub js_sys: Path,
/// Path to wasm_bindgen_futures
pub wasm_bindgen_futures: Path,
}
impl Default for Program {
fn default() -> Self {
Self {
exports: Default::default(),
imports: Default::default(),
linked_modules: Default::default(),
enums: Default::default(),
structs: Default::default(),
typescript_custom_sections: Default::default(),
inline_js: Default::default(),
wasm_bindgen: syn::parse_quote! { wasm_bindgen },
js_sys: syn::parse_quote! { js_sys },
wasm_bindgen_futures: syn::parse_quote! { wasm_bindgen_futures },
}
}
}
impl Program {
/// Name of the link function for a specific linked module
pub fn link_function_name(&self, idx: usize) -> String {
let hash = match &self.linked_modules[idx] {
ImportModule::Inline(idx) => ShortHash((1, &self.inline_js[*idx])).to_string(),
other => ShortHash((0, other)).to_string(),
};
format!("__wbindgen_link_{hash}")
}
}
/// An abstract syntax tree representing a link to a module in Rust.
/// In contrast to Program, LinkToModule must expand to an expression.
/// linked_modules of the inner Program must contain exactly one element
/// whose link is produced by the expression.
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct LinkToModule(pub Program);
/// A rust to js interface. Allows interaction with rust objects/functions
/// from javascript.
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct Export {
/// Comments extracted from the rust source.
pub comments: Vec<String>,
/// The rust function
pub function: Function,
/// The class name in JS this is attached to
pub js_class: Option<String>,
/// The namespace to export the item through, if any
pub js_namespace: Option<Vec<String>>,
/// The kind (static, named, regular)
pub method_kind: MethodKind,
/// The type of `self` (either `self`, `&self`, or `&mut self`)
pub method_self: Option<MethodSelf>,
/// The struct name, in Rust, this is attached to
pub rust_class: Option<Ident>,
/// The name of the rust function/method on the rust side.
pub rust_name: Ident,
/// Whether or not this function should be flagged as the Wasm start
/// function.
pub start: StartKind,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Path to wasm_bindgen_futures
pub wasm_bindgen_futures: Path,
/// Path to js_sys
pub js_sys: Path,
}
/// The 3 types variations of `self`.
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Copy, Clone)]
pub enum MethodSelf {
/// `self`
ByValue,
/// `&mut self`
RefMutable,
/// `&self`
RefShared,
}
/// Things imported from a JS module (in an `extern` block)
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct Import {
/// The type of module being imported from, if any
pub module: Option<ImportModule>,
/// The namespace to access the item through, if any
pub js_namespace: Option<Vec<String>>,
/// If Some, this import should be re-exported with the optional given name
pub reexport: Option<Option<String>>,
/// The type of item being imported
pub kind: ImportKind,
}
/// The possible types of module to import from
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub enum ImportModule {
/// Import from the named module, with relative paths interpreted
Named(String, Span),
/// Import from the named module, without interpreting paths
RawNamed(String, Span),
/// Import from an inline JS snippet
Inline(usize),
}
impl Hash for ImportModule {
fn hash<H: Hasher>(&self, h: &mut H) {
match self {
ImportModule::Named(name, _) => (1u8, name).hash(h),
ImportModule::Inline(idx) => (2u8, idx).hash(h),
ImportModule::RawNamed(name, _) => (3u8, name).hash(h),
}
}
}
/// The type of item being imported
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub enum ImportKind {
/// Importing a function
Function(ImportFunction),
/// Importing a static value
Static(ImportStatic),
/// Importing a static string
String(ImportString),
/// Importing a type/class
Type(ImportType),
/// Importing a JS string enum
Enum(StringEnum),
/// Importing a dynamic union (with fallback variant support)
DynamicUnion(DynamicUnion),
}
/// A function being imported from JS
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct ImportFunction {
/// The full signature of the function
pub function: Function,
/// The name rust code will use
pub rust_name: Ident,
/// The type being returned
pub js_ret: Option<syn::Type>,
/// Whether to catch JS exceptions
pub catch: bool,
/// Whether the function is variadic on the JS side
pub variadic: bool,
/// Whether the function should use structural type checking
pub structural: bool,
/// Causes the Builder (See cli-support::js::binding::Builder) to error out if
/// it finds itself generating code for a function with this signature
pub assert_no_shim: bool,
/// The kind of function being imported
pub kind: ImportFunctionKind,
/// The shim name to use in the generated code. The 'shim' is a function that appears in
/// the generated JS as a wrapper around the actual function to import, performing any
/// necessary conversions (EG adding a try/catch to change a thrown error into a Result)
pub shim: Ident,
/// The doc comment on this import, if one is provided
pub doc_comment: String,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Path to wasm_bindgen_futures
pub wasm_bindgen_futures: Path,
/// Path to js_sys
pub js_sys: Path,
/// Generic parameters as validated simple type parameters for this function
pub generics: syn::Generics,
}
/// The type of a function being imported
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub enum ImportFunctionKind {
/// A class method
Method {
/// The name of the class for this method, in JS
class: String,
/// The type of the class for this method, in Rust
ty: syn::Type,
/// The kind of method this is
kind: MethodKind,
},
/// A standard function
Normal,
}
/// The type of a method
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub enum MethodKind {
/// A class constructor
Constructor,
/// Any other kind of method
Operation(Operation),
}
/// The operation performed by a class method
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct Operation {
/// Whether this method is static
pub is_static: bool,
/// The internal kind of this Operation
pub kind: OperationKind,
}
/// The kind of operation performed by a method
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub enum OperationKind {
/// A standard method, nothing special
Regular,
/// A free function that receives JS `this` as its first parameter
RegularThis,
/// A method for getting the value of the provided Ident or String
Getter(Option<String>),
/// A method for setting the value of the provided Ident or String
Setter(Option<String>),
/// A dynamically intercepted getter
IndexingGetter,
/// A dynamically intercepted setter
IndexingSetter,
/// A dynamically intercepted deleter
IndexingDeleter,
}
/// The type of a static being imported
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct ImportStatic {
/// The visibility of this static in Rust
pub vis: syn::Visibility,
/// The type of static being imported
pub ty: syn::Type,
/// The name of the shim function used to access this static
pub shim: Ident,
/// The name of this static on the Rust side
pub rust_name: Ident,
/// The name of this static on the JS side
pub js_name: String,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Version of `thread_local`, if any.
pub thread_local: Option<ThreadLocal>,
}
/// Which version of the `thread_local` attribute is enabled.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum ThreadLocal {
/// V1.
V1,
/// V2.
V2,
}
/// The type of a static string being imported
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct ImportString {
/// The visibility of this static string in Rust
pub vis: syn::Visibility,
/// The type specified by the user, which we only use to show an error if the wrong type is used.
pub ty: syn::Type,
/// The name of the shim function used to access this static
pub shim: Ident,
/// The name of this static on the Rust side
pub rust_name: Ident,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Path to js_sys
pub js_sys: Path,
/// The string to export.
pub string: String,
/// Version of `thread_local`.
pub thread_local: ThreadLocal,
}
/// The metadata for a type being imported
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct ImportType {
/// The visibility of this type in Rust
pub vis: syn::Visibility,
/// The name of this type on the Rust side
pub rust_name: Ident,
/// The name of this type on the JS side
pub js_name: String,
/// The custom attributes to apply to this type
pub attrs: Vec<syn::Attribute>,
/// The TS definition to generate for this type
pub typescript_type: Option<String>,
/// The doc comment applied to this type, if one exists
pub doc_comment: Option<String>,
/// The name of the shim to check instanceof for this type
pub instanceof_shim: String,
/// The name of the remote function to use for the generated is_type_of
pub is_type_of: Option<syn::Expr>,
/// The list of classes this extends, if any
pub extends: Vec<syn::Path>,
/// A custom prefix to add and attempt to fall back to, if the type isn't found
pub vendor_prefixes: Vec<Ident>,
/// If present, don't generate a `Deref` impl
pub no_deref: bool,
/// If present, don't generate `Upcast` impls
pub no_upcast: bool,
/// If present, don't generate a `Promising` impl
pub no_promising: bool,
/// If present, don't generate an `IntoJsGeneric` impl
pub no_into_js_generic: bool,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
/// Validated generics
pub generics: syn::Generics,
}
/// The metadata for a String Enum
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct StringEnum {
/// The Rust enum's visibility
pub vis: syn::Visibility,
/// The Rust enum's identifiers
pub name: Ident,
/// The export name of this string enum in JS/TS code
pub export_name: String,
/// The Rust identifiers for the variants
pub variants: Vec<Ident>,
/// The JS string values of the variants
pub variant_values: Vec<String>,
/// The doc comments on this enum, if any
pub comments: Vec<String>,
/// Attributes to apply to the Rust enum
pub rust_attrs: Vec<syn::Attribute>,
/// Whether to generate a typescript definition for this enum
pub generate_typescript: bool,
/// Whether to suppress the `export` keyword on the generated TS type
/// alias (matches the existing flag on c-style enums and structs).
pub private: bool,
/// The namespace to export the enum through, if any
pub js_namespace: Option<Vec<String>>,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
}
/// The metadata for a Dynamic Union (an untagged JS-side union of string
/// literals and single-field tuple variants, dispatched at runtime).
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct DynamicUnion {
/// The Rust enum's visibility
pub vis: syn::Visibility,
/// The Rust enum's identifiers
pub name: Ident,
/// The name of this enum in JS/TS code
pub js_name: String,
/// The Rust identifiers for the variants
pub variants: Vec<Ident>,
/// The JS string values of the known string variants
pub variant_values: Vec<String>,
/// The field types for each variant (empty for known string variants, one element for fallback variant)
pub variant_fields: Vec<Vec<syn::Type>>,
/// The doc comments on this enum, if any
pub comments: Vec<String>,
/// Attributes to apply to the Rust enum
pub rust_attrs: Vec<syn::Attribute>,
/// Whether to generate a typescript definition for this enum
pub generate_typescript: bool,
/// Whether to suppress the `export` keyword on the generated TS type alias.
pub private: bool,
/// Whether the last tuple variant should act as an unconditional
/// fallback rather than a runtime-checked variant. Set via the
/// `#[wasm_bindgen(fallback)]` attribute on the enum.
pub fallback: bool,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
}
/// Information about a function being imported or exported
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct Function {
/// The exported name of the function
pub name: String,
/// The span of the function's name in Rust code
pub name_span: Span,
/// The arguments to the function
pub arguments: Vec<FunctionArgumentData>,
/// The data of return type of the function
pub ret: Option<FunctionReturnData>,
/// Any custom attributes being applied to the function
pub rust_attrs: Vec<syn::Attribute>,
/// The visibility of this function in Rust
pub rust_vis: syn::Visibility,
/// Whether this is an `unsafe` function
pub r#unsafe: bool,
/// Whether this is an `async` function
pub r#async: bool,
/// Whether to generate a typescript definition for this function
pub generate_typescript: bool,
/// Whether to generate jsdoc documentation for this function
pub generate_jsdoc: bool,
/// Whether this is a function with a variadict parameter
pub variadic: bool,
}
/// Information about a function's return
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct FunctionReturnData {
/// Specifies the type of the function's return
pub r#type: syn::Type,
/// Specifies the JS return type override
pub js_type: Option<String>,
/// Specifies the return description
pub desc: Option<String>,
}
/// Information about a function's argument
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct FunctionArgumentData {
/// Specifies the type of the function's argument
pub pat_type: syn::PatType,
/// Specifies the JS argument name override
pub js_name: Option<String>,
/// Specifies the JS function argument type override
pub js_type: Option<String>,
/// Specifies whether the parameter is optional
pub optional: bool,
/// Specifies the argument description
pub desc: Option<String>,
/// When set, an `&[T]` (or `Option<&[T]>`) argument is converted to a
/// freshly-allocated buffer the JS side observes as a plain `Array`
/// rather than a typed array. Only meaningful for outgoing arguments
/// (Rust calling JS); ignored on exported functions.
pub slice_to_array: bool,
}
/// Information about a Struct being exported
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct Struct {
/// The name of the struct in Rust code
pub rust_name: Ident,
/// The export name of the struct in JS code
pub js_name: String,
/// The namespace-qualified internal name used for wasm symbol generation.
/// When a namespace is present, this is `ns1_ns2_JsName`; otherwise it equals `js_name`.
pub qualified_name: String,
/// All the fields of this struct to export
pub fields: Vec<StructField>,
/// The doc comments on this struct, if provided
pub comments: Vec<String>,
/// Whether this struct is inspectable (provides toJSON/toString properties to JS)
pub is_inspectable: bool,
/// Whether to generate a typescript definition for this struct
pub generate_typescript: bool,
/// Whether to skip exporting this struct from the module exports
pub private: bool,
/// The namespace to export the struct through, if any
pub js_namespace: Option<Vec<String>>,
/// The parent type this struct extends, if any. When set, the macro
/// auto-injects a `parent: wasm_bindgen::Parent<Parent>` field at the
/// head of the struct; that field is used as the upcast projection
/// target. Users must not declare a `Parent<T>` field themselves.
pub extends: Option<Path>,
/// The JS-side `js_name` of the parent class, declared on the child
/// via `extends_js_class = "..."`. Required when the parent struct
/// uses `js_name`: the child macro cannot see the parent struct's
/// attributes cross-invocation, so the parent's JS-side identity must
/// be redeclared here for `exported_classes` lookup to resolve.
/// Defaults to the last segment of the `extends` Rust path (matching
/// the no-rename case).
pub extends_js_class: Option<String>,
/// The JS-side `js_namespace` of the parent class, declared on the
/// child via `extends_js_namespace = ...`. Required when the parent
/// struct uses `js_namespace`. Defaults to `None`.
pub extends_js_namespace: Option<Vec<String>>,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
}
/// The field of a struct
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub struct StructField {
/// The name of the field in Rust code
pub rust_name: syn::Member,
/// The name of the field in JS code
pub js_name: String,
/// The name of the struct this field is part of
pub struct_name: Ident,
/// Whether this value is read-only to JS
pub readonly: bool,
/// The type of this field
pub ty: syn::Type,
/// The name of the getter shim for this field
pub getter: Ident,
/// The name of the setter shim for this field
pub setter: Ident,
/// The doc comments on this field, if any
pub comments: Vec<String>,
/// Whether to generate a typescript definition for this field
pub generate_typescript: bool,
/// Whether to generate jsdoc documentation for this field
pub generate_jsdoc: bool,
/// The span of the `#[wasm_bindgen(getter_with_clone)]` attribute applied
/// to this field, if any.
///
/// If this is `Some`, the auto-generated getter for this field must clone
/// the field instead of copying it.
pub getter_with_clone: Option<Span>,
/// Whether this field is the macro-injected parent field — i.e. has
/// type `wasm_bindgen::Parent<T>` — for an `extends` relationship.
/// Parent fields are not exposed to JS as getters/setters; they exist
/// only for Rust-side upcast projection.
pub is_parent: bool,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
}
/// The metadata for an Enum
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct Enum {
/// The name of this enum in Rust code
pub rust_name: Ident,
/// The export name of this enum in JS code
pub js_name: String,
/// Whether the variant values and hole are signed, meaning that they
/// represent the bits of a `i32` value.
pub signed: bool,
/// The variants provided by this enum
pub variants: Vec<Variant>,
/// The doc comments on this enum, if any
pub comments: Vec<String>,
/// The value to use for a `none` variant of the enum
pub hole: u32,
/// Whether to generate a typescript definition for this enum
pub generate_typescript: bool,
/// Whether to hide this enum from the module exports
pub private: bool,
/// The namespace to export the enum through, if any
pub js_namespace: Option<Vec<String>>,
/// Path to wasm_bindgen
pub wasm_bindgen: Path,
}
/// The variant of an enum
#[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
#[derive(Clone)]
pub struct Variant {
/// The name of this variant in Rust
pub rust_name: Ident,
/// The name of this variant in JS
pub js_name: String,
/// The backing value of this variant
pub value: u32,
/// The doc comments on this variant, if any
pub comments: Vec<String>,
}
/// An enum representing either a literal value (`Lit`) or an expression (`syn::Expr`).
#[cfg_attr(feature = "extra-traits", derive(Debug))]
#[derive(Clone)]
pub enum LitOrExpr {
/// Represents an expression that needs to be evaluated before it can be encoded
Expr(syn::Expr),
/// Represents a literal string that can be directly encoded.
Lit(String),
}
impl Export {
/// Mangles a rust -> javascript export, so that the created Ident will be unique over function
/// name and class name, if the function belongs to a javascript class.
pub(crate) fn rust_symbol(&self) -> Ident {
let mut generated_name = String::from("__wasm_bindgen_generated");
if let Some(class) = &self.js_class {
generated_name.push('_');
generated_name.push_str(class);
}
generated_name.push('_');
// The JS-side name may contain characters that aren't valid in a
// Rust identifier (notably the `[Symbol.<name>]` computed-key form
// accepted by `js_name`). Filter to a valid identifier suffix; this
// is a no-op for plain identifier names.
for c in self.function.name.chars() {
if c.is_ascii_alphanumeric() || c == '_' {
generated_name.push(c);
}
}
Ident::new(&generated_name, Span::call_site())
}
/// This is the name of the shim function that gets exported and takes the raw
/// ABI form of its arguments and converts them back into their normal,
/// "high level" form before calling the actual function.
pub(crate) fn export_name(&self) -> String {
let fn_name = self.function.name.to_string();
let base_name = match &self.js_class {
Some(class) => shared::struct_function_export_name(class, &fn_name),
None => shared::free_function_export_name(&fn_name),
};
if let Some(ns) = &self.js_namespace {
format!("{}__{base_name}", ns.join("__"))
} else {
base_name
}
}
}
impl ImportKind {
/// Whether this type can be inside an `impl` block.
pub fn fits_on_impl(&self) -> bool {
match *self {
ImportKind::Function(_) => true,
ImportKind::Static(_) => false,
ImportKind::String(_) => false,
ImportKind::Type(_) => false,
ImportKind::Enum(_) => false,
ImportKind::DynamicUnion(_) => false,
}
}
}
impl Function {
/// If the rust object has a `fn xxx(&self) -> MyType` method, get the name for a getter in
/// javascript (in this case `xxx`, so you can write `val = obj.xxx`)
pub fn infer_getter_property(&self) -> &str {
&self.name
}
/// If the rust object has a `fn set_xxx(&mut self, MyType)` style method, get the name
/// for a setter in javascript (in this case `xxx`, so you can write `obj.xxx = val`)
pub fn infer_setter_property(&self) -> Result<String, Diagnostic> {
let name = self.name.to_string();
// Otherwise we infer names based on the Rust function name.
if !name.starts_with("set_") {
bail_span!(
syn::token::Pub(self.name_span),
"setters must start with `set_`, found: {}",
name,
);
}
Ok(name[4..].to_string())
}
}