Alex Crichton c6f7d3dfd5 Fix methods returning Self
Rewrite any instance of `Self` to the name of the class

Closes #137
2018-04-19 18:43:37 -07:00

958 lines
28 KiB
Rust

use quote::{ToTokens, Tokens};
use shared;
use syn;
#[derive(Default)]
pub struct Program {
pub exports: Vec<Export>,
pub imports: Vec<Import>,
pub enums: Vec<Enum>,
pub structs: Vec<Struct>,
}
pub struct Export {
pub class: Option<syn::Ident>,
pub method: bool,
pub mutable: bool,
pub constructor: Option<String>,
pub function: Function,
}
pub struct Import {
pub module: Option<String>,
pub js_namespace: Option<syn::Ident>,
pub kind: ImportKind,
}
pub enum ImportKind {
Function(ImportFunction),
Static(ImportStatic),
Type(ImportType),
}
pub struct ImportFunction {
pub function: Function,
pub rust_name: syn::Ident,
pub kind: ImportFunctionKind,
pub shim: syn::Ident,
}
pub enum ImportFunctionKind {
Method { class: String, ty: syn::Type },
JsConstructor { class: String, ty: syn::Type },
Normal,
}
pub struct ImportStatic {
pub vis: syn::Visibility,
pub ty: syn::Type,
pub shim: syn::Ident,
pub rust_name: syn::Ident,
pub js_name: syn::Ident,
}
pub struct ImportType {
pub vis: syn::Visibility,
pub name: syn::Ident,
}
pub struct Function {
pub name: syn::Ident,
pub arguments: Vec<syn::Type>,
pub ret: Option<syn::Type>,
pub opts: BindgenAttrs,
pub rust_attrs: Vec<syn::Attribute>,
pub rust_decl: Box<syn::FnDecl>,
pub rust_vis: syn::Visibility,
}
pub struct Struct {
pub name: syn::Ident,
pub fields: Vec<StructField>,
}
pub struct StructField {
pub name: syn::Ident,
pub struct_name: syn::Ident,
pub ty: syn::Type,
pub getter: syn::Ident,
pub setter: syn::Ident,
}
pub struct Enum {
pub name: syn::Ident,
pub variants: Vec<Variant>,
}
pub struct Variant {
pub name: syn::Ident,
pub value: u32,
}
#[derive(Copy, Clone)]
pub enum TypeKind {
ByRef,
ByMutRef,
ByValue,
}
#[derive(Copy, Clone)]
pub enum TypeLocation {
ImportArgument,
ImportRet,
ExportArgument,
ExportRet,
}
impl Program {
pub fn push_item(&mut self, item: syn::Item, opts: Option<BindgenAttrs>, tokens: &mut Tokens) {
match item {
syn::Item::Fn(mut f) => {
let opts = opts.unwrap_or_else(|| BindgenAttrs::find(&mut f.attrs));
let no_mangle = f.attrs
.iter()
.enumerate()
.filter_map(|(i, m)| m.interpret_meta().map(|m| (i, m)))
.find(|&(_, ref m)| m.name() == "no_mangle");
match no_mangle {
Some((i, _)) => {
f.attrs.remove(i);
}
_ => {}
}
f.to_tokens(tokens);
self.exports.push(Export {
class: None,
method: false,
mutable: false,
constructor: None,
function: Function::from(f, opts),
});
}
syn::Item::Struct(mut s) => {
let opts = opts.unwrap_or_else(|| BindgenAttrs::find(&mut s.attrs));
s.to_tokens(tokens);
self.structs.push(Struct::from(s, opts));
}
syn::Item::Impl(mut i) => {
let opts = opts.unwrap_or_else(|| BindgenAttrs::find(&mut i.attrs));
self.push_impl(&mut i, opts);
i.to_tokens(tokens);
}
syn::Item::ForeignMod(mut f) => {
let opts = opts.unwrap_or_else(|| BindgenAttrs::find(&mut f.attrs));
self.push_foreign_mod(f, opts);
}
syn::Item::Enum(mut e) => {
let opts = opts.unwrap_or_else(|| BindgenAttrs::find(&mut e.attrs));
e.to_tokens(tokens);
self.push_enum(e, opts);
}
_ => panic!(
"#[wasm_bindgen] can only be applied to a function, \
struct, enum, impl, or extern block"
),
}
}
pub fn push_impl(&mut self, item: &mut syn::ItemImpl, _opts: BindgenAttrs) {
if item.defaultness.is_some() {
panic!("default impls are not supported");
}
if item.unsafety.is_some() {
panic!("unsafe impls are not supported");
}
if item.trait_.is_some() {
panic!("trait impls are not supported");
}
if item.generics.params.len() > 0 {
panic!("generic impls aren't supported");
}
let name = match *item.self_ty {
syn::Type::Path(syn::TypePath {
qself: None,
ref path,
}) => match extract_path_ident(path) {
Some(ident) => ident,
None => panic!("unsupported self type in impl"),
},
_ => panic!("unsupported self type in impl"),
};
for item in item.items.iter_mut() {
self.push_impl_item(name, item);
}
}
fn push_impl_item(&mut self, class: syn::Ident, item: &mut syn::ImplItem) {
replace_self(class, item);
let method = match item {
syn::ImplItem::Const(_) => panic!("const definitions aren't supported"),
syn::ImplItem::Type(_) => panic!("type definitions in impls aren't supported"),
syn::ImplItem::Method(ref mut m) => m,
syn::ImplItem::Macro(_) => panic!("macros in impls aren't supported"),
syn::ImplItem::Verbatim(_) => panic!("unparsed impl item?"),
};
match method.vis {
syn::Visibility::Public(_) => {}
_ => return,
}
if method.defaultness.is_some() {
panic!("default methods are not supported");
}
if method.sig.constness.is_some() {
panic!("can only bindgen non-const functions");
}
if method.sig.unsafety.is_some() {
panic!("can only bindgen safe functions");
}
let opts = BindgenAttrs::find(&mut method.attrs);
let is_constructor = opts.constructor();
let constructor = if is_constructor {
Some(method.sig.ident.to_string())
} else {
None
};
let (function, mutable) = Function::from_decl(
method.sig.ident,
Box::new(method.sig.decl.clone()),
method.attrs.clone(),
opts,
method.vis.clone(),
true,
);
self.exports.push(Export {
class: Some(class),
method: mutable.is_some(),
mutable: mutable.unwrap_or(false),
constructor,
function,
});
}
pub fn push_enum(&mut self, item: syn::ItemEnum, _opts: BindgenAttrs) {
match item.vis {
syn::Visibility::Public(_) => {}
_ => panic!("only public enums are allowed"),
}
let variants = item.variants
.iter()
.enumerate()
.map(|(i, v)| {
match v.fields {
syn::Fields::Unit => (),
_ => panic!("Only C-Style enums allowed"),
}
let value = match v.discriminant {
Some((
_,
syn::Expr::Lit(syn::ExprLit {
attrs: _,
lit: syn::Lit::Int(ref int_lit),
}),
)) => {
if int_lit.value() > <u32>::max_value() as u64 {
panic!("Enums can only support numbers that can be represented as u32");
}
int_lit.value() as u32
}
None => i as u32,
_ => panic!("Enums may only have number literal values"),
};
Variant {
name: v.ident,
value,
}
})
.collect();
self.enums.push(Enum {
name: item.ident,
variants,
});
}
pub fn push_foreign_mod(&mut self, f: syn::ItemForeignMod, opts: BindgenAttrs) {
match f.abi.name {
Some(ref l) if l.value() == "C" => {}
None => {}
_ => panic!("only foreign mods with the `C` ABI are allowed"),
}
for mut item in f.items.into_iter() {
let item_opts = {
let attrs = match item {
syn::ForeignItem::Fn(ref mut f) => &mut f.attrs,
syn::ForeignItem::Type(ref mut t) => &mut t.attrs,
syn::ForeignItem::Static(ref mut s) => &mut s.attrs,
_ => panic!("only foreign functions/types allowed for now"),
};
BindgenAttrs::find(attrs)
};
let module = item_opts.module().or(opts.module()).map(|s| s.to_string());
let js_namespace = item_opts.js_namespace().or(opts.js_namespace());
let mut kind = match item {
syn::ForeignItem::Fn(f) => self.push_foreign_fn(f, item_opts),
syn::ForeignItem::Type(t) => self.push_foreign_ty(t),
syn::ForeignItem::Static(s) => self.push_foreign_static(s, item_opts),
_ => panic!("only foreign functions/types allowed for now"),
};
self.imports.push(Import {
module,
js_namespace,
kind,
});
}
}
pub fn push_foreign_fn(&mut self, f: syn::ForeignItemFn, opts: BindgenAttrs) -> ImportKind {
let js_name = opts.js_name().unwrap_or(f.ident);
let mut wasm = Function::from_decl(
js_name,
f.decl,
f.attrs,
opts,
f.vis,
false,
).0;
if wasm.opts.catch() {
// TODO: this assumes a whole bunch:
//
// * The outer type is actually a `Result`
// * The error type is a `JsValue`
// * The actual type is the first type parameter
//
// should probably fix this one day...
wasm.ret = extract_first_ty_param(wasm.ret.as_ref())
.expect("can't `catch` without returning a Result");
}
let kind = if wasm.opts.method() {
let class = wasm.arguments
.get(0)
.expect("methods must have at least one argument");
let class = match *class {
syn::Type::Reference(syn::TypeReference {
mutability: None,
ref elem,
..
}) => &**elem,
_ => panic!("first argument of method must be a shared reference"),
};
let class_name = match *class {
syn::Type::Path(syn::TypePath {
qself: None,
ref path,
}) => path,
_ => panic!("first argument of method must be a path"),
};
let class_name = extract_path_ident(class_name)
.expect("first argument of method must be a bare type");
ImportFunctionKind::Method {
class: class_name.as_ref().to_string(),
ty: class.clone(),
}
} else if wasm.opts.constructor() {
let class = match wasm.ret {
Some(ref ty) => ty,
_ => panic!("constructor returns must be bare types"),
};
let class_name = match *class {
syn::Type::Path(syn::TypePath {
qself: None,
ref path,
}) => path,
_ => panic!("first argument of method must be a path"),
};
let class_name = extract_path_ident(class_name)
.expect("first argument of method must be a bare type");
ImportFunctionKind::JsConstructor {
class: class_name.as_ref().to_string(),
ty: class.clone(),
}
} else {
ImportFunctionKind::Normal
};
let shim = {
let ns = match kind {
ImportFunctionKind::Normal => "n",
ImportFunctionKind::Method { ref class, .. } => class,
ImportFunctionKind::JsConstructor { ref class, .. } => class,
};
format!("__wbg_f_{}_{}_{}", js_name, f.ident, ns)
};
ImportKind::Function(ImportFunction {
function: wasm,
kind,
rust_name: f.ident,
shim: shim.into(),
})
}
pub fn push_foreign_ty(&mut self, f: syn::ForeignItemType) -> ImportKind {
ImportKind::Type(ImportType {
vis: f.vis,
name: f.ident,
})
}
pub fn push_foreign_static(
&mut self,
f: syn::ForeignItemStatic,
opts: BindgenAttrs,
) -> ImportKind {
if f.mutability.is_some() {
panic!("cannot import mutable globals yet")
}
let js_name = opts.js_name().unwrap_or(f.ident);
let shim = format!("__wbg_static_accessor_{}_{}", js_name, f.ident);
ImportKind::Static(ImportStatic {
ty: *f.ty,
vis: f.vis,
rust_name: f.ident,
js_name,
shim: shim.into(),
})
}
pub fn shared(&self) -> shared::Program {
shared::Program {
exports: self.exports.iter().map(|a| a.shared()).collect(),
structs: self.structs.iter().map(|a| a.shared()).collect(),
enums: self.enums.iter().map(|a| a.shared()).collect(),
imports: self.imports.iter().map(|a| a.shared()).collect(),
version: shared::version(),
schema_version: shared::SCHEMA_VERSION.to_string(),
}
}
}
impl Function {
pub fn from(input: syn::ItemFn, opts: BindgenAttrs) -> Function {
match input.vis {
syn::Visibility::Public(_) => {}
_ => panic!("can only bindgen public functions"),
}
if input.constness.is_some() {
panic!("can only bindgen non-const functions");
}
if input.unsafety.is_some() {
panic!("can only bindgen safe functions");
}
Function::from_decl(
input.ident,
input.decl,
input.attrs,
opts,
input.vis,
false,
).0
}
pub fn from_decl(
name: syn::Ident,
mut decl: Box<syn::FnDecl>,
attrs: Vec<syn::Attribute>,
opts: BindgenAttrs,
vis: syn::Visibility,
allow_self: bool,
) -> (Function, Option<bool>) {
if decl.variadic.is_some() {
panic!("can't bindgen variadic functions")
}
if decl.generics.params.len() > 0 {
panic!("can't bindgen functions with lifetime or type parameters")
}
assert_no_lifetimes(&mut decl);
let mut mutable = None;
let arguments = decl.inputs
.iter()
.filter_map(|arg| match *arg {
syn::FnArg::Captured(ref c) => Some(c),
syn::FnArg::SelfValue(_) => {
panic!("by-value `self` not yet supported");
}
syn::FnArg::SelfRef(ref a) if allow_self => {
assert!(mutable.is_none());
mutable = Some(a.mutability.is_some());
None
}
_ => panic!("arguments cannot be `self` or ignored"),
})
.map(|arg| arg.ty.clone())
.collect::<Vec<_>>();
let ret = match decl.output {
syn::ReturnType::Default => None,
syn::ReturnType::Type(_, ref t) => Some((**t).clone()),
};
(
Function {
name,
arguments,
ret,
opts,
rust_vis: vis,
rust_decl: decl,
rust_attrs: attrs,
},
mutable,
)
}
fn shared(&self) -> shared::Function {
shared::Function {
name: self.name.as_ref().to_string(),
}
}
}
pub fn extract_path_ident(path: &syn::Path) -> Option<syn::Ident> {
if path.leading_colon.is_some() {
return None;
}
if path.segments.len() != 1 {
return None;
}
match path.segments.first().unwrap().value().arguments {
syn::PathArguments::None => {}
_ => return None,
}
path.segments.first().map(|v| v.value().ident)
}
impl Export {
pub fn rust_symbol(&self) -> syn::Ident {
let mut generated_name = format!("__wasm_bindgen_generated");
if let Some(class) = self.class {
generated_name.push_str("_");
generated_name.push_str(class.as_ref());
}
generated_name.push_str("_");
generated_name.push_str(self.function.name.as_ref());
syn::Ident::from(generated_name)
}
pub fn export_name(&self) -> String {
match self.class {
Some(class) => {
shared::struct_function_export_name(class.as_ref(), self.function.name.as_ref())
}
None => shared::free_function_export_name(self.function.name.as_ref()),
}
}
fn shared(&self) -> shared::Export {
shared::Export {
class: self.class.map(|s| s.as_ref().to_string()),
method: self.method,
constructor: self.constructor.clone(),
function: self.function.shared(),
}
}
}
impl Enum {
fn shared(&self) -> shared::Enum {
shared::Enum {
name: self.name.as_ref().to_string(),
variants: self.variants.iter().map(|v| v.shared()).collect(),
}
}
}
impl Variant {
fn shared(&self) -> shared::EnumVariant {
shared::EnumVariant {
name: self.name.as_ref().to_string(),
value: self.value,
}
}
}
impl Import {
fn shared(&self) -> shared::Import {
shared::Import {
module: self.module.clone(),
js_namespace: self.js_namespace.map(|s| s.as_ref().to_string()),
kind: self.kind.shared(),
}
}
}
impl ImportKind {
fn shared(&self) -> shared::ImportKind {
match *self {
ImportKind::Function(ref f) => shared::ImportKind::Function(f.shared()),
ImportKind::Static(ref f) => shared::ImportKind::Static(f.shared()),
ImportKind::Type(ref f) => shared::ImportKind::Type(f.shared()),
}
}
}
impl ImportFunction {
pub fn infer_getter_property(&self) -> String {
self.function.name.as_ref().to_string()
}
pub fn infer_setter_property(&self) -> String {
let name = self.function.name.as_ref();
assert!(name.starts_with("set_"), "setters must start with `set_`");
name[4..].to_string()
}
fn shared(&self) -> shared::ImportFunction {
let mut method = false;
let mut js_new = false;
let mut class_name = None;
match self.kind {
ImportFunctionKind::Method { ref class, .. } => {
method = true;
class_name = Some(class);
}
ImportFunctionKind::JsConstructor { ref class, .. } => {
js_new = true;
class_name = Some(class);
}
ImportFunctionKind::Normal => {}
}
let mut getter = None;
let mut setter = None;
if let Some(s) = self.function.opts.getter() {
let s = s.map(|s| s.to_string());
getter = Some(s.unwrap_or_else(|| self.infer_getter_property()));
}
if let Some(s) = self.function.opts.setter() {
let s = s.map(|s| s.to_string());
setter = Some(s.unwrap_or_else(|| self.infer_setter_property()));
}
shared::ImportFunction {
shim: self.shim.as_ref().to_string(),
catch: self.function.opts.catch(),
method,
js_new,
structural: self.function.opts.structural(),
getter,
setter,
class: class_name.cloned(),
function: self.function.shared(),
}
}
}
impl ImportStatic {
fn shared(&self) -> shared::ImportStatic {
shared::ImportStatic {
name: self.js_name.as_ref().to_string(),
shim: self.shim.as_ref().to_string(),
}
}
}
impl ImportType {
fn shared(&self) -> shared::ImportType {
shared::ImportType { }
}
}
impl Struct {
fn from(s: syn::ItemStruct, _opts: BindgenAttrs) -> Struct {
let mut fields = Vec::new();
if let syn::Fields::Named(names) = s.fields {
for field in names.named.iter() {
match field.vis {
syn::Visibility::Public(..) => {}
_ => continue,
}
let name = match field.ident {
Some(n) => n,
None => continue,
};
let getter = shared::struct_field_get(s.ident.as_ref(), name.as_ref());
let setter = shared::struct_field_set(s.ident.as_ref(), name.as_ref());
fields.push(StructField {
name,
struct_name: s.ident,
ty: field.ty.clone(),
getter: getter.into(),
setter: setter.into(),
});
}
}
Struct {
name: s.ident,
fields,
}
}
fn shared(&self) -> shared::Struct {
shared::Struct {
name: self.name.as_ref().to_string(),
fields: self.fields.iter().map(|s| s.shared()).collect(),
}
}
}
impl StructField {
fn shared(&self) -> shared::StructField {
shared::StructField {
name: self.name.as_ref().to_string(),
}
}
}
#[derive(Default)]
pub struct BindgenAttrs {
attrs: Vec<BindgenAttr>,
}
impl BindgenAttrs {
pub fn find(attrs: &mut Vec<syn::Attribute>) -> BindgenAttrs {
let pos = attrs
.iter()
.enumerate()
.find(|&(_, ref m)| m.path.segments[0].ident == "wasm_bindgen")
.map(|a| a.0);
let pos = match pos {
Some(i) => i,
None => return BindgenAttrs::default(),
};
syn::parse(attrs.remove(pos).tts.into()).expect("malformed #[wasm_bindgen] attribute")
}
fn module(&self) -> Option<&str> {
self.attrs
.iter()
.filter_map(|a| match *a {
BindgenAttr::Module(ref s) => Some(&s[..]),
_ => None,
})
.next()
}
pub fn catch(&self) -> bool {
self.attrs.iter().any(|a| match *a {
BindgenAttr::Catch => true,
_ => false,
})
}
fn constructor(&self) -> bool {
self.attrs.iter().any(|a| match *a {
BindgenAttr::Constructor => true,
_ => false,
})
}
fn method(&self) -> bool {
self.attrs.iter().any(|a| match *a {
BindgenAttr::Method => true,
_ => false,
})
}
fn js_namespace(&self) -> Option<syn::Ident> {
self.attrs
.iter()
.filter_map(|a| match *a {
BindgenAttr::JsNamespace(s) => Some(s),
_ => None,
})
.next()
}
pub fn getter(&self) -> Option<Option<syn::Ident>> {
self.attrs
.iter()
.filter_map(|a| match *a {
BindgenAttr::Getter(s) => Some(s),
_ => None,
})
.next()
}
pub fn setter(&self) -> Option<Option<syn::Ident>> {
self.attrs
.iter()
.filter_map(|a| match *a {
BindgenAttr::Setter(s) => Some(s),
_ => None,
})
.next()
}
pub fn structural(&self) -> bool {
self.attrs.iter().any(|a| match *a {
BindgenAttr::Structural => true,
_ => false,
})
}
pub fn js_name(&self) -> Option<syn::Ident> {
self.attrs
.iter()
.filter_map(|a| match *a {
BindgenAttr::JsName(s) => Some(s),
_ => None,
})
.next()
}
}
impl syn::synom::Synom for BindgenAttrs {
named!(parse -> Self, alt!(
do_parse!(
opts: parens!(call!(
syn::punctuated::Punctuated::<_, syn::token::Comma>::parse_terminated
)) >>
(BindgenAttrs {
attrs: opts.1.into_iter().collect(),
})
) => { |s| s }
|
epsilon!() => { |_| BindgenAttrs { attrs: Vec::new() } }
));
}
#[derive(PartialEq)]
enum BindgenAttr {
Catch,
Constructor,
Method,
JsNamespace(syn::Ident),
Module(String),
Getter(Option<syn::Ident>),
Setter(Option<syn::Ident>),
Structural,
JsName(syn::Ident),
}
impl syn::synom::Synom for BindgenAttr {
named!(parse -> Self, alt!(
call!(term, "catch") => { |_| BindgenAttr::Catch }
|
call!(term, "constructor") => { |_| BindgenAttr::Constructor }
|
call!(term, "method") => { |_| BindgenAttr::Method }
|
do_parse!(
call!(term, "getter") >>
val: option!(do_parse!(
punct!(=) >>
s: syn!(syn::Ident) >>
(s)
)) >>
(val)
)=> { BindgenAttr::Getter }
|
do_parse!(
call!(term, "setter") >>
val: option!(do_parse!(
punct!(=) >>
s: syn!(syn::Ident) >>
(s)
)) >>
(val)
)=> { BindgenAttr::Setter }
|
call!(term, "structural") => { |_| BindgenAttr::Structural }
|
do_parse!(
call!(term, "js_namespace") >>
punct!(=) >>
ns: syn!(syn::Ident) >>
(ns)
)=> { BindgenAttr::JsNamespace }
|
do_parse!(
call!(term, "module") >>
punct!(=) >>
s: syn!(syn::LitStr) >>
(s.value())
)=> { BindgenAttr::Module }
|
do_parse!(
call!(term, "js_name") >>
punct!(=) >>
ns: syn!(syn::Ident) >>
(ns)
)=> { BindgenAttr::JsName }
));
}
fn extract_first_ty_param(ty: Option<&syn::Type>) -> Option<Option<syn::Type>> {
let t = match ty {
Some(t) => t,
None => return Some(None),
};
let path = match *t {
syn::Type::Path(syn::TypePath {
qself: None,
ref path,
}) => path,
_ => return None,
};
let seg = path.segments.last()?.into_value();
let generics = match seg.arguments {
syn::PathArguments::AngleBracketed(ref t) => t,
_ => return None,
};
let ty = match *generics.args.first()?.into_value() {
syn::GenericArgument::Type(ref t) => t,
_ => return None,
};
match *ty {
syn::Type::Tuple(ref t) if t.elems.len() == 0 => return Some(None),
_ => {}
}
Some(Some(ty.clone()))
}
fn term<'a>(cursor: syn::buffer::Cursor<'a>, name: &str) -> syn::synom::PResult<'a, ()> {
if let Some((term, next)) = cursor.term() {
if term.as_str() == name {
return Ok(((), next));
}
}
syn::parse_error()
}
fn assert_no_lifetimes(decl: &mut syn::FnDecl) {
struct Walk;
impl<'ast> syn::visit_mut::VisitMut for Walk {
fn visit_lifetime_mut(&mut self, _i: &mut syn::Lifetime) {
panic!("it is currently not sound to use lifetimes in function \
signatures");
}
}
syn::visit_mut::VisitMut::visit_fn_decl_mut(&mut Walk, decl);
}
fn replace_self(name: syn::Ident, item: &mut syn::ImplItem) {
struct Walk(syn::Ident);
impl syn::visit_mut::VisitMut for Walk {
fn visit_ident_mut(&mut self, i: &mut syn::Ident) {
if i.as_ref() == "Self" {
*i = self.0;
}
}
}
syn::visit_mut::VisitMut::visit_impl_item_mut(&mut Walk(name), item);
}