786 lines
26 KiB
Rust

/*!
# `wasm_bindgen_webidl`
Converts WebIDL into wasm-bindgen's internal AST form, so that bindings can be
emitted for the types and methods described in the WebIDL.
*/
#![deny(missing_docs)]
#![deny(missing_debug_implementations)]
#![doc(html_root_url = "https://docs.rs/wasm-bindgen-webidl/0.2")]
#[macro_use]
extern crate failure;
#[macro_use]
extern crate failure_derive;
extern crate heck;
#[macro_use]
extern crate log;
extern crate proc_macro2;
#[macro_use]
extern crate quote;
#[macro_use]
extern crate syn;
extern crate wasm_bindgen_backend as backend;
extern crate weedle;
mod first_pass;
mod util;
mod error;
use std::collections::BTreeSet;
use std::fs;
use std::io::{self, Read};
use std::iter::FromIterator;
use std::path::Path;
use backend::TryToTokens;
use backend::defined::{ImportedTypeDefinitions, RemoveUndefinedImports};
use backend::util::{ident_ty, rust_ident, wrap_import_function};
use failure::ResultExt;
use heck::{ShoutySnakeCase};
use proc_macro2::{Ident, Span};
use weedle::argument::Argument;
use weedle::attribute::{ExtendedAttribute, ExtendedAttributeList};
use first_pass::{FirstPass, FirstPassRecord};
use util::{public, webidl_const_v_to_backend_const_v, TypePosition, camel_case_ident, mdn_doc};
use util::ToSynType;
pub use error::{Error, ErrorKind, Result};
/// Parse the WebIDL at the given path into a wasm-bindgen AST.
fn parse_file(webidl_path: &Path) -> Result<backend::ast::Program> {
let file = fs::File::open(webidl_path).context(ErrorKind::OpeningWebIDLFile)?;
let mut file = io::BufReader::new(file);
let mut source = String::new();
file.read_to_string(&mut source).context(ErrorKind::ReadingWebIDLFile)?;
parse(&source)
}
/// Parse a string of WebIDL source text into a wasm-bindgen AST.
fn parse(webidl_source: &str) -> Result<backend::ast::Program> {
let definitions = match weedle::parse(webidl_source) {
Ok(def) => def,
Err(e) => {
return Err(match &e {
weedle::Err::Incomplete(needed) => {
format_err!("needed {:?} more bytes", needed)
.context(ErrorKind::ParsingWebIDLSource).into()
}
weedle::Err::Error(cx) |
weedle::Err::Failure(cx) => {
let remaining = match cx {
weedle::Context::Code(remaining, _) => remaining,
};
let pos = webidl_source.len() - remaining.len();
format_err!("failed to parse WebIDL")
.context(ErrorKind::ParsingWebIDLSourcePos(pos)).into()
}
// webidl::ParseError::UnrecognizedToken { token: Some((start, ..)), .. } => {
// ErrorKind::ParsingWebIDLSourcePos(*start)
// }
// webidl::ParseError::ExtraToken { token: (start, ..) } => {
// ErrorKind::ParsingWebIDLSourcePos(*start)
// },
// _ => ErrorKind::ParsingWebIDLSource
});
}
};
let mut first_pass_record = Default::default();
definitions.first_pass(&mut first_pass_record, ())?;
let mut program = Default::default();
definitions.webidl_parse(&mut program, &first_pass_record, ())?;
Ok(program)
}
/// Compile the given WebIDL file into Rust source text containing
/// `wasm-bindgen` bindings to the things described in the WebIDL.
pub fn compile_file(webidl_path: &Path) -> Result<String> {
let ast = parse_file(webidl_path)?;
Ok(compile_ast(ast))
}
/// Compile the given WebIDL source text into Rust source text containing
/// `wasm-bindgen` bindings to the things described in the WebIDL.
pub fn compile(webidl_source: &str) -> Result<String> {
let ast = parse(webidl_source)?;
Ok(compile_ast(ast))
}
/// Run codegen on the AST to generate rust code.
fn compile_ast(mut ast: backend::ast::Program) -> String {
let mut defined = BTreeSet::from_iter(
vec![
"str", "char", "bool", "JsValue", "u8", "i8", "u16", "i16", "u32", "i32", "u64", "i64",
"usize", "isize", "f32", "f64", "Result", "String", "Vec", "Option",
"ArrayBuffer", "Object",
].into_iter()
.map(|id| proc_macro2::Ident::new(id, proc_macro2::Span::call_site())),
);
ast.imported_type_definitions(&mut |id| {
defined.insert(id.clone());
});
ast.remove_undefined_imports(&|id| defined.contains(id));
let mut tokens = proc_macro2::TokenStream::new();
if let Err(e) = ast.try_to_tokens(&mut tokens) {
e.panic();
}
tokens.to_string()
}
/// The main trait for parsing WebIDL AST into wasm-bindgen AST.
trait WebidlParse<'src, Ctx> {
/// Parse `self` into wasm-bindgen AST, and insert it into `program`.
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
context: Ctx,
) -> Result<()>;
}
impl<'src> WebidlParse<'src, ()> for [weedle::Definition<'src>] {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
for def in self {
def.webidl_parse(program, first_pass, ())?;
}
Ok(())
}
}
impl<'src> WebidlParse<'src, ()> for weedle::Definition<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
match self {
weedle::Definition::Enum(enumeration) => {
enumeration.webidl_parse(program, first_pass, ())?
}
weedle::Definition::IncludesStatement(includes) => {
includes.webidl_parse(program, first_pass, ())?
}
weedle::Definition::Interface(interface) => {
interface.webidl_parse(program, first_pass, ())?
}
weedle::Definition::PartialInterface(interface) => {
interface.webidl_parse(program, first_pass, ())?
}
weedle::Definition::Typedef(_) |
weedle::Definition::InterfaceMixin(_) |
weedle::Definition::PartialInterfaceMixin(_) => {
// handled in the first pass
}
weedle::Definition::Implements(..) => {
// nothing to do for this, ignore it
}
// TODO
weedle::Definition::Callback(..)
| weedle::Definition::CallbackInterface(..)
| weedle::Definition::Dictionary(..)
| weedle::Definition::PartialDictionary(..)
| weedle::Definition::Namespace(..)
| weedle::Definition::PartialNamespace(..) => {
warn!("Unsupported WebIDL definition: {:?}", self)
}
}
Ok(())
}
}
impl<'src> WebidlParse<'src, ()> for weedle::IncludesStatementDefinition<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
match first_pass.mixins.get(self.rhs_identifier.0) {
Some(member_lists) => {
for member in member_lists.iter().flat_map(|list| list.iter()) {
member.webidl_parse(program, first_pass, self.lhs_identifier.0)?;
}
}
None => warn!("Tried to include missing mixin {}", self.rhs_identifier.0),
}
Ok(())
}
}
impl<'src> WebidlParse<'src, ()> for weedle::InterfaceDefinition<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
if util::is_chrome_only(&self.attributes) {
return Ok(());
}
if util::is_no_interface_object(&self.attributes) {
return Ok(());
}
let doc_comment = Some(format!(
"The `{}` object\n\n{}",
self.identifier.0,
mdn_doc(self.identifier.0, None),
));
program.imports.push(backend::ast::Import {
module: None,
js_namespace: None,
kind: backend::ast::ImportKind::Type(backend::ast::ImportType {
vis: public(),
rust_name: rust_ident(camel_case_ident(self.identifier.0).as_str()),
js_name: self.identifier.0.to_string(),
attrs: Vec::new(),
doc_comment,
instanceof_shim: format!("__widl_instanceof_{}", self.identifier.0),
extends: first_pass.all_superclasses(self.identifier.0)
.map(|name| Ident::new(&name, Span::call_site()))
.collect(),
}),
});
if let Some(attrs) = &self.attributes {
for attr in &attrs.body.list {
attr.webidl_parse(program, first_pass, self)?;
}
}
for member in &self.members.body {
member.webidl_parse(program, first_pass, self.identifier.0)?;
}
Ok(())
}
}
impl<'src> WebidlParse<'src, ()> for weedle::PartialInterfaceDefinition<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
if util::is_chrome_only(&self.attributes) {
return Ok(());
}
if !first_pass.interfaces.contains_key(self.identifier.0) {
warn!(
"Partial interface {} missing non-partial interface",
self.identifier.0
);
}
for member in &self.members.body {
member.webidl_parse(program, first_pass, self.identifier.0)?;
}
Ok(())
}
}
impl<'src> WebidlParse<'src, &'src weedle::InterfaceDefinition<'src>> for ExtendedAttribute<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
interface: &'src weedle::InterfaceDefinition<'src>,
) -> Result<()> {
let mut add_constructor = |arguments: &[Argument], class: &str| {
let (overloaded, same_argument_names) = first_pass.get_operation_overloading(
arguments,
&::first_pass::OperationId::Constructor,
interface.identifier.0,
);
let self_ty = ident_ty(rust_ident(camel_case_ident(interface.identifier.0).as_str()));
let kind = backend::ast::ImportFunctionKind::Method {
class: class.to_string(),
ty: self_ty.clone(),
kind: backend::ast::MethodKind::Constructor,
};
let structural = false;
// Constructors aren't annotated with `[Throws]` extended attributes
// (how could they be, since they themselves are extended
// attributes?) so we must conservatively assume that they can
// always throw.
//
// From https://heycam.github.io/webidl/#Constructor (emphasis
// mine):
//
// > The prose definition of a constructor must either return an IDL
// > value of a type corresponding to the interface the
// > `[Constructor]` extended attribute appears on, **or throw an
// > exception**.
let throws = true;
first_pass
.create_function(
"new",
overloaded,
same_argument_names,
arguments,
Some(self_ty),
kind,
structural,
throws,
None,
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
};
match self {
ExtendedAttribute::ArgList(list)
if list.identifier.0 == "Constructor" =>
{
add_constructor(&list.args.body.list, interface.identifier.0)
}
ExtendedAttribute::NoArgs(other) if (other.0).0 == "Constructor" => {
add_constructor(&[], interface.identifier.0)
}
ExtendedAttribute::NamedArgList(list)
if list.lhs_identifier.0 == "NamedConstructor" =>
{
add_constructor(&list.args.body.list, list.rhs_identifier.0)
}
// these appear to be mapping to gecko preferences, seems like we
// can safely ignore
ExtendedAttribute::Ident(id) if id.lhs_identifier.0 == "Pref" => {}
// looks to be a gecko-specific attribute to tie WebIDL back to C++
// functions perhaps
ExtendedAttribute::Ident(id) if id.lhs_identifier.0 == "Func" => {}
ExtendedAttribute::Ident(id) if id.lhs_identifier.0 == "JSImplementation" => {}
ExtendedAttribute::Ident(id) if id.lhs_identifier.0 == "HeaderFile" => {}
// Not actually mentioned in the spec and presumably a hint to
// Gecko's JS engine? Unsure, but seems like it doesn't matter to us
ExtendedAttribute::NoArgs(id)
if (id.0).0 == "ProbablyShortLivingWrapper" => {}
// Indicates something about enumerable properties, we're not too
// interested in it
// https://heycam.github.io/webidl/#LegacyUnenumerableNamedProperties
ExtendedAttribute::NoArgs(id)
if (id.0).0 == "LegacyUnenumerableNamedProperties" => {}
// Indicates where objects are defined (web workers and such), we
// may later want to use this for cfgs but for now we ignore it.
// https://heycam.github.io/webidl/#Exposed
ExtendedAttribute::Ident(id) if id.lhs_identifier.0 == "Exposed" => {}
ExtendedAttribute::IdentList(id) if id.identifier.0 == "Exposed" => {}
// We handle this with the "structural" attribute elsewhere
ExtendedAttribute::IdentList(id) if id.identifier.0 == "Global" => {}
// Seems like it's safe to ignore for now, just telling us where a
// binding appears
// https://heycam.github.io/webidl/#SecureContext
ExtendedAttribute::NoArgs(id) if (id.0).0 == "SecureContext" => {}
// We handle this elsewhere
ExtendedAttribute::NoArgs(id) if (id.0).0 == "Unforgeable" => {}
// Looks like this attribute just says that we can't call the
// constructor
// https://html.spec.whatwg.org/multipage/dom.html#htmlconstructor
ExtendedAttribute::NoArgs(id) if (id.0).0 == "HTMLConstructor" => {}
ExtendedAttribute::ArgList(_)
| ExtendedAttribute::Ident(_)
| ExtendedAttribute::IdentList(_)
| ExtendedAttribute::NamedArgList(_)
| ExtendedAttribute::NoArgs(_) => {
warn!("Unsupported WebIDL extended attribute: {:?}", self);
}
}
Ok(())
}
}
impl<'src> WebidlParse<'src, &'src str> for weedle::interface::InterfaceMember<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
use weedle::interface::InterfaceMember::*;
match self {
Attribute(attr) => {
attr.webidl_parse(program, first_pass, self_name)
}
Operation(op) => {
op.webidl_parse(program, first_pass, self_name)
}
Const(cnst) => {
cnst.webidl_parse(program, first_pass, self_name)
}
Iterable(iterable) => {
iterable.webidl_parse(program, first_pass, self_name)
}
// TODO
| Maplike(_)
| Stringifier(_)
| Setlike(_) => {
warn!("Unsupported WebIDL interface member: {:?}", self);
Ok(())
}
}
}
}
impl<'a, 'src> WebidlParse<'src, &'a str> for weedle::mixin::MixinMember<'src> {
fn webidl_parse(
&self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'a str,
) -> Result<()> {
match self {
weedle::mixin::MixinMember::Attribute(attr) => {
attr.webidl_parse(program, first_pass, self_name)
}
weedle::mixin::MixinMember::Operation(op) => {
op.webidl_parse(program, first_pass, self_name)
}
// TODO
weedle::mixin::MixinMember::Stringifier(_) |
weedle::mixin::MixinMember::Const(_) => {
warn!("Unsupported WebIDL mixin member: {:?}", self);
Ok(())
}
}
}
}
impl<'src> WebidlParse<'src, &'src str> for weedle::interface::AttributeInterfaceMember<'src> {
fn webidl_parse(
&self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
member_attribute(
program,
first_pass,
self_name,
&self.attributes,
self.modifier,
self.readonly.is_some(),
&self.type_,
self.identifier.0,
)
}
}
impl<'src> WebidlParse<'src, &'src str> for weedle::mixin::AttributeMixinMember<'src> {
fn webidl_parse(
&self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
member_attribute(
program,
first_pass,
self_name,
&self.attributes,
if let Some(s) = self.stringifier {
Some(weedle::interface::StringifierOrInheritOrStatic::Stringifier(s))
} else {
None
},
self.readonly.is_some(),
&self.type_,
self.identifier.0,
)
}
}
fn member_attribute<'src>(
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
attrs: &'src Option<ExtendedAttributeList>,
modifier: Option<weedle::interface::StringifierOrInheritOrStatic>,
readonly: bool,
type_: &'src weedle::types::AttributedType<'src>,
identifier: &'src str,
) -> Result<()> {
use weedle::interface::StringifierOrInheritOrStatic::*;
if util::is_chrome_only(attrs) {
return Ok(());
}
let statik = match modifier {
Some(Stringifier(_)) => {
warn!("Unsupported stringifier on type {:?}", (self_name, identifier));
return Ok(())
}
Some(Inherit(_)) => false,
Some(Static(_)) => true,
None => false,
};
if type_.attributes.is_some() {
warn!("Unsupported attributes on type {:?}", (self_name, identifier));
return Ok(())
}
let is_structural = util::is_structural(attrs);
let throws = util::throws(attrs);
first_pass
.create_getter(
identifier,
&type_.type_,
self_name,
statik,
is_structural,
throws,
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
if !readonly {
first_pass
.create_setter(
identifier,
type_.type_.clone(),
self_name,
statik,
is_structural,
throws,
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
}
Ok(())
}
impl<'src> WebidlParse<'src, &'src str> for weedle::interface::OperationInterfaceMember<'src> {
fn webidl_parse(
&self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
member_operation(
program,
first_pass,
self_name,
&self.attributes,
self.modifier,
&self.specials,
&self.return_type,
&self.args.body.list,
&self.identifier,
)
}
}
impl<'src> WebidlParse<'src, &'src str> for weedle::mixin::OperationMixinMember<'src> {
fn webidl_parse(
&self,
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
member_operation(
program,
first_pass,
self_name,
&self.attributes,
None,
&[],
&self.return_type,
&self.args.body.list,
&self.identifier,
)
}
}
fn member_operation<'src>(
program: &mut backend::ast::Program,
first_pass: &FirstPassRecord<'src>,
self_name: &'src str,
attrs: &'src Option<ExtendedAttributeList>,
modifier: Option<weedle::interface::StringifierOrStatic>,
specials: &[weedle::interface::Special],
return_type: &'src weedle::types::ReturnType<'src>,
args: &'src [Argument],
identifier: &Option<weedle::common::Identifier<'src>>,
) -> Result<()> {
use weedle::interface::StringifierOrStatic::*;
if util::is_chrome_only(attrs) {
return Ok(());
}
let statik = match modifier {
Some(Stringifier(_)) => {
warn!("Unsupported stringifier on type {:?}", (self_name, identifier));
return Ok(())
}
Some(Static(_)) => true,
None => false,
};
first_pass
.create_basic_method(
args,
match identifier.map(|s| s.0) {
None if specials.is_empty() => ::first_pass::OperationId::Operation(None),
None if specials.len() == 1 => match specials[0] {
weedle::interface::Special::Getter(weedle::term::Getter) => ::first_pass::OperationId::IndexingGetter,
weedle::interface::Special::Setter(weedle::term::Setter) => ::first_pass::OperationId::IndexingSetter,
weedle::interface::Special::Deleter(weedle::term::Deleter) => ::first_pass::OperationId::IndexingDeleter,
weedle::interface::Special::LegacyCaller(weedle::term::LegacyCaller) => return Ok(()),
},
Some(ref name) if specials.is_empty() => ::first_pass::OperationId::Operation(Some(name.clone())),
_ => {
warn!("Unsupported specials on type {:?}", (self_name, identifier));
return Ok(())
}
},
return_type,
self_name,
statik,
specials.len() == 1 || first_pass
.interfaces
.get(self_name)
.map(|interface_data| interface_data.global)
.unwrap_or(false),
util::throws(attrs),
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
Ok(())
}
impl<'src> WebidlParse<'src, &'src str> for weedle::interface::IterableInterfaceMember<'src> {
fn webidl_parse(
&self,
_program: &mut backend::ast::Program,
_first_pass: &FirstPassRecord<'src>,
_self_name: &'src str,
) -> Result<()> {
// if util::is_chrome_only(&self.attributes) {
// return Ok(());
// }
/* TODO
let throws = util::throws(&self.extended_attributes);
let return_value = weedle::ReturnType::NonVoid(self.value_type.clone());
let args = [];
first_pass
.create_basic_method(
&args,
Some(&"values".to_string()),
&return_value,
self_name,
false,
false, // Should be false
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
first_pass
.create_basic_method(
&args,
Some(&"keys".to_string()),
&return_value, // Should be a number
self_name,
false,
false, // Should be false
)
.map(wrap_import_function)
.map(|import| program.imports.push(import));
*/
Ok(())
}
}
impl<'src> WebidlParse<'src, ()> for weedle::EnumDefinition<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
_: &FirstPassRecord<'src>,
(): (),
) -> Result<()> {
let variants = &self.values.body.list;
program.imports.push(backend::ast::Import {
module: None,
js_namespace: None,
kind: backend::ast::ImportKind::Enum(backend::ast::ImportEnum {
vis: public(),
name: rust_ident(camel_case_ident(self.identifier.0).as_str()),
variants: variants
.iter()
.map(|v| {
if !v.0.is_empty() {
rust_ident(camel_case_ident(&v.0).as_str())
} else {
rust_ident("None")
}
})
.collect(),
variant_values: variants.iter().map(|v| v.0.to_string()).collect(),
rust_attrs: vec![parse_quote!(#[derive(Copy, Clone, PartialEq, Debug)])],
}),
});
Ok(())
}
}
impl<'src> WebidlParse<'src, &'src str> for weedle::interface::ConstMember<'src> {
fn webidl_parse(
&'src self,
program: &mut backend::ast::Program,
record: &FirstPassRecord<'src>,
self_name: &'src str,
) -> Result<()> {
let ty = match self.const_type.to_syn_type(record, TypePosition::Return) {
Some(s) => s,
None => return Ok(()),
};
program.consts.push(backend::ast::Const {
vis: public(),
name: rust_ident(self.identifier.0.to_shouty_snake_case().as_str()),
class: Some(rust_ident(camel_case_ident(&self_name).as_str())),
ty,
value: webidl_const_v_to_backend_const_v(&self.const_value),
});
Ok(())
}
}