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Greatly simplify handling of types in Rust

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Push the compiler to do trait resolution to figure out what each type is bound
with in JS, and that way we can accept effectively all types (so long as they
implement a trait).
This commit is contained in:
Alex Crichton
2018-02-06 07:56:14 -08:00
parent 0320bc0d7c
commit d5ff725913
8 changed files with 772 additions and 534 deletions
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290
crates/wasm-bindgen-macro/src/lib.rs
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@ -1,3 +1,4 @@
#![recursion_limit = "128"]
#![feature(proc_macro)]
#[macro_use]
@ -7,23 +8,24 @@ extern crate quote;
extern crate proc_macro;
extern crate proc_macro2;
extern crate serde_json;
extern crate wasm_bindgen_shared;
extern crate wasm_bindgen_shared as shared;
use std::char;
use std::sync::atomic::*;
use proc_macro::TokenStream;
use proc_macro2::{Span, TokenNode, Delimiter, TokenTree};
use quote::{Tokens, ToTokens};
macro_rules! my_quote {
($($t:tt)*) => (quote_spanned!(Span::call_site() => $($t)*))
}
mod ast;
static MALLOC_GENERATED: AtomicBool = ATOMIC_BOOL_INIT;
static BOXED_STR_GENERATED: AtomicBool = ATOMIC_BOOL_INIT;
macro_rules! my_quote {
($($t:tt)*) => (quote_spanned!(Span::call_site() => $($t)*))
}
#[proc_macro]
pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
// Parse the input as a list of Rust items, reusing the `syn::File` parser.
@ -80,8 +82,8 @@ pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
for function in program.free_functions.iter() {
bindgen_fn(function, &mut ret);
}
for s in program.structs.iter() {
bindgen_struct(s, &mut ret);
for (i, s) in program.structs.iter().enumerate() {
bindgen_struct(i, s, &mut ret);
}
for i in program.imports.iter() {
bindgen_import(i, &mut ret);
@ -98,19 +100,14 @@ pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
let generated_static_name = format!("__WASM_BINDGEN_GENERATED{}",
CNT.fetch_add(1, Ordering::SeqCst));
let generated_static_name = syn::Ident::from(generated_static_name);
let mut generated_static = String::from("wbg:");
generated_static.push_str(&serde_json::to_string(&program.shared()).unwrap());
let generated_static_value = syn::LitByteStr::new(
generated_static.as_bytes(),
Span::def_site(),
);
let generated_static_length = generated_static.len();
let mut generated_static_value = Tokens::new();
let generated_static_length = program.wbg_literal(&mut generated_static_value);
(my_quote! {
#[no_mangle]
#[allow(non_upper_case_globals)]
pub static #generated_static_name: [u8; #generated_static_length] =
*#generated_static_value;
[#generated_static_value];
}).to_tokens(&mut ret);
// println!("{}", ret);
@ -127,7 +124,7 @@ fn bindgen_fn(function: &ast::Function, into: &mut Tokens) {
into)
}
fn bindgen_struct(s: &ast::Struct, into: &mut Tokens) {
fn bindgen_struct(idx: usize, s: &ast::Struct, into: &mut Tokens) {
for f in s.functions.iter() {
bindgen_struct_fn(s, f, into);
}
@ -137,11 +134,47 @@ fn bindgen_struct(s: &ast::Struct, into: &mut Tokens) {
let name = &s.name;
let free_fn = s.free_function();
let c = char::from_u32(idx as u32 * 2 + shared::TYPE_CUSTOM_START);
(my_quote! {
impl ::wasm_bindgen::convert::WasmBoundary for #name {
type Js = u32;
const DESCRIPTOR: char = #c;
fn into_js(self) -> u32 {
Box::into_raw(Box::new(::wasm_bindgen::__rt::WasmRefCell::new(self))) as u32
}
unsafe fn from_js(js: u32) -> Self {
let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
::wasm_bindgen::__rt::assert_not_null(js);
let js = Box::from_raw(js);
js.borrow_mut(); // make sure no one's borrowing
js.into_inner()
}
}
impl ::wasm_bindgen::convert::FromRefWasmBoundary for #name {
type RefAnchor = ::wasm_bindgen::__rt::Ref<'static, #name>;
unsafe fn from_js_ref(js: Self::Js) -> Self::RefAnchor {
let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
::wasm_bindgen::__rt::assert_not_null(js);
(*js).borrow()
}
}
impl ::wasm_bindgen::convert::FromRefMutWasmBoundary for #name {
type RefAnchor = ::wasm_bindgen::__rt::RefMut<'static, #name>;
unsafe fn from_js_ref_mut(js: Self::Js) -> Self::RefAnchor {
let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
::wasm_bindgen::__rt::assert_not_null(js);
(*js).borrow_mut()
}
}
#[no_mangle]
pub unsafe extern fn #free_fn(ptr: *mut ::wasm_bindgen::__rt::WasmRefCell<#name>) {
::wasm_bindgen::__rt::assert_not_null(ptr);
drop(Box::from_raw(ptr));
pub unsafe extern fn #free_fn(ptr: u32) {
<#name as ::wasm_bindgen::convert::WasmBoundary>::from_js(ptr);
}
}).to_tokens(into);
}
@ -198,21 +231,6 @@ fn bindgen(export_name: &syn::LitStr,
let i = i + offset;
let ident = syn::Ident::from(format!("arg{}", i));
match *ty {
ast::Type::Integer(i) => {
args.push(my_quote! { #ident: #i });
}
ast::Type::Boolean => {
args.push(my_quote! { #ident: u32 });
arg_conversions.push(my_quote! {
let #ident = #ident != 0;
});
}
ast::Type::RawMutPtr(i) => {
args.push(my_quote! { #ident: *mut #i });
}
ast::Type::RawConstPtr(i) => {
args.push(my_quote! { #ident: *const #i });
}
ast::Type::BorrowedStr => {
malloc = malloc || !MALLOC_GENERATED.swap(true, Ordering::SeqCst);
let ptr = syn::Ident::from(format!("arg{}_ptr", i));
@ -239,90 +257,63 @@ fn bindgen(export_name: &syn::LitStr,
};
});
}
ast::Type::ByValue(name) => {
args.push(my_quote! { #ident: *mut ::wasm_bindgen::__rt::WasmRefCell<#name> });
ast::Type::ByValue(ref t) => {
args.push(my_quote! {
#ident: <#t as ::wasm_bindgen::convert::WasmBoundary >::Js
});
arg_conversions.push(my_quote! {
::wasm_bindgen::__rt::assert_not_null(#ident);
let #ident = unsafe {
(*#ident).borrow_mut();
Box::from_raw(#ident).into_inner()
<#t as ::wasm_bindgen::convert::WasmBoundary>
::from_js(#ident)
};
});
}
ast::Type::ByRef(name) => {
args.push(my_quote! { #ident: *mut ::wasm_bindgen::__rt::WasmRefCell<#name> });
ast::Type::ByRef(ref ty) => {
args.push(my_quote! {
#ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
});
arg_conversions.push(my_quote! {
::wasm_bindgen::__rt::assert_not_null(#ident);
let #ident = unsafe { (*#ident).borrow() };
let #ident = unsafe {
<#ty as ::wasm_bindgen::convert::FromRefWasmBoundary>
::from_js_ref(#ident)
};
let #ident = &*#ident;
});
}
ast::Type::ByMutRef(name) => {
args.push(my_quote! { #ident: *mut ::wasm_bindgen::__rt::WasmRefCell<#name> });
ast::Type::ByMutRef(ref ty) => {
args.push(my_quote! {
#ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
});
arg_conversions.push(my_quote! {
::wasm_bindgen::__rt::assert_not_null(#ident);
let mut #ident = unsafe { (*#ident).borrow_mut() };
let mut #ident = unsafe {
<#ty as ::wasm_bindgen::convert::FromRefMutWasmBoundary>
::from_js_ref_mut(#ident)
};
let #ident = &mut *#ident;
});
}
ast::Type::JsObject => {
args.push(my_quote! { #ident: u32 });
arg_conversions.push(my_quote! {
let #ident = ::wasm_bindgen::JsObject::__from_idx(#ident);
});
}
ast::Type::JsObjectRef => {
args.push(my_quote! { #ident: u32 });
arg_conversions.push(my_quote! {
let #ident = ::std::mem::ManuallyDrop::new(
::wasm_bindgen::JsObject::__from_idx(#ident)
);
let #ident = &*#ident;
});
}
}
converted_arguments.push(my_quote! { #ident });
}
let ret_ty;
let convert_ret;
match ret_type {
Some(&ast::Type::Integer(i)) => {
ret_ty = my_quote! { -> #i };
convert_ret = my_quote! { #ret };
}
Some(&ast::Type::Boolean) => {
ret_ty = my_quote! { -> u32 };
convert_ret = my_quote! { #ret as u32 };
}
Some(&ast::Type::RawMutPtr(i)) => {
ret_ty = my_quote! { -> *mut #i };
convert_ret = my_quote! { #ret };
}
Some(&ast::Type::RawConstPtr(i)) => {
ret_ty = my_quote! { -> *const #i };
convert_ret = my_quote! { #ret };
}
Some(&ast::Type::BorrowedStr) => panic!("can't return a borrowed string"),
Some(&ast::Type::ByRef(_)) => panic!("can't return a borrowed ref"),
Some(&ast::Type::ByMutRef(_)) => panic!("can't return a borrowed ref"),
Some(&ast::Type::String) => {
boxed_str = !BOXED_STR_GENERATED.swap(true, Ordering::SeqCst);
ret_ty = my_quote! { -> *mut String };
convert_ret = my_quote! { Box::into_raw(Box::new(#ret)) };
}
Some(&ast::Type::ByValue(name)) => {
ret_ty = my_quote! { -> *mut ::wasm_bindgen::__rt::WasmRefCell<#name> };
Some(&ast::Type::ByValue(ref t)) => {
ret_ty = my_quote! {
-> <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
};
convert_ret = my_quote! {
Box::into_raw(Box::new(::wasm_bindgen::__rt::WasmRefCell::new(#ret)))
<#t as ::wasm_bindgen::convert::WasmBoundary>::into_js(#ret)
};
}
Some(&ast::Type::JsObject) => {
ret_ty = my_quote! { -> u32 };
convert_ret = my_quote! {
::wasm_bindgen::JsObject::__into_idx(#ret)
};
}
Some(&ast::Type::JsObjectRef) => {
Some(&ast::Type::BorrowedStr) |
Some(&ast::Type::ByMutRef(_)) |
Some(&ast::Type::ByRef(_)) => {
panic!("can't return a borrowed ref");
}
None => {
@ -331,6 +322,8 @@ fn bindgen(export_name: &syn::LitStr,
}
}
// TODO: move this function into wasm-bindgen-the-crate and then gc it out
// if it's not used.
let malloc = if malloc {
my_quote! {
#[no_mangle]
@ -429,8 +422,10 @@ impl ToTokens for Receiver {
}
fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
let import_name = import.function.wasm_function.shared()
.mangled_import_name(None);
let import_name = shared::mangled_import_name(
None,
import.function.wasm_function.name.as_ref(),
);
bindgen_import_function(&import.function, &import_name, tokens);
}
@ -445,8 +440,10 @@ fn bindgen_imported_struct(import: &ast::ImportStruct, tokens: &mut Tokens) {
let mut methods = Tokens::new();
for &(_is_method, ref f) in import.functions.iter() {
let import_name = f.wasm_function.shared()
.mangled_import_name(Some(&import.name.to_string()));
let import_name = shared::mangled_import_name(
Some(&import.name.to_string()),
f.wasm_function.name.as_ref(),
);
bindgen_import_function(f, &import_name, &mut methods);
}
@ -494,26 +491,6 @@ fn bindgen_import_function(import: &ast::ImportFunction,
for (ty, name) in import.wasm_function.arguments.iter().zip(names) {
match *ty {
ast::Type::Integer(i) => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: #i });
arg_conversions.push(my_quote! {});
}
ast::Type::Boolean => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: u32 });
arg_conversions.push(my_quote! { let #name = #name as u32; });
}
ast::Type::RawMutPtr(i) => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: *mut #i });
arg_conversions.push(my_quote! {});
}
ast::Type::RawConstPtr(i) => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: *const #i });
arg_conversions.push(my_quote! {});
}
ast::Type::BorrowedStr => {
let ptr = syn::Ident::from(format!("{}_ptr", name));
let len = syn::Ident::from(format!("{}_len", name));
@ -526,59 +503,70 @@ fn bindgen_import_function(import: &ast::ImportFunction,
let #len = #name.len();
});
}
ast::Type::JsObject => {
ast::Type::ByValue(ref t) => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! {
#name: <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
});
arg_conversions.push(my_quote! {
let #name = <#t as ::wasm_bindgen::convert::WasmBoundary>
::into_js(#name);
});
}
ast::Type::ByMutRef(_) => panic!("urgh mut"),
ast::Type::ByRef(ref t) => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: u32 });
arg_conversions.push(my_quote! {
let #name = ::wasm_bindgen::JsObject::__into_idx(#name);
let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
::to_js_ref(#name);
});
}
ast::Type::JsObjectRef => {
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: u32 });
// TODO: need to test this
ast::Type::String => {
let ptr = syn::Ident::from(format!("{}_ptr", name));
let len = syn::Ident::from(format!("{}_len", name));
abi_argument_names.push(ptr);
abi_argument_names.push(len);
abi_arguments.push(my_quote! { #ptr: *const u8 });
abi_arguments.push(my_quote! { #len: usize });
arg_conversions.push(my_quote! {
let #name = ::wasm_bindgen::JsObject::__get_idx(#name);
let #ptr = #name.as_ptr();
let #len = #name.len();
::std::mem::forget(#name);
});
}
ast::Type::String => panic!("can't use `String` in foreign functions"),
ast::Type::ByValue(_name) |
ast::Type::ByRef(_name) |
ast::Type::ByMutRef(_name) => {
panic!("can't use struct types in foreign functions yet");
}
}
}
let abi_ret;
let convert_ret;
match import.wasm_function.ret {
Some(ast::Type::Integer(i)) => {
abi_ret = my_quote! { #i };
convert_ret = my_quote! { #ret_ident };
}
Some(ast::Type::Boolean) => {
abi_ret = my_quote! { u32 };
convert_ret = my_quote! { #ret_ident != 0 };
}
Some(ast::Type::RawConstPtr(i)) => {
abi_ret = my_quote! { *const #i };
convert_ret = my_quote! { #ret_ident };
}
Some(ast::Type::RawMutPtr(i)) => {
abi_ret = my_quote! { *mut #i };
convert_ret = my_quote! { #ret_ident };
}
Some(ast::Type::JsObject) => {
abi_ret = my_quote! { u32 };
Some(ast::Type::ByValue(ref t)) => {
abi_ret = my_quote! {
<#t as ::wasm_bindgen::convert::WasmBoundary>::Js
};
convert_ret = my_quote! {
::wasm_bindgen::JsObject::__from_idx(#ret_ident)
<#t as ::wasm_bindgen::convert::WasmBoundary>::from_js(#ret_ident)
};
}
Some(ast::Type::JsObjectRef) => panic!("can't return a borrowed ref"),
Some(ast::Type::BorrowedStr) => panic!("can't return a borrowed string"),
Some(ast::Type::ByRef(_)) => panic!("can't return a borrowed ref"),
// TODO: add a test for this
Some(ast::Type::String) => {
let name = syn::Ident::from("__ret_strlen");
abi_argument_names.push(name);
abi_arguments.push(my_quote! { #name: *mut usize });
arg_conversions.push(my_quote! {
let mut #name = 0;
});
abi_ret = my_quote! { *const u8 };
convert_ret = my_quote! {
let __v = Vec::from_raw_parts(#ret_ident, #name, #name);
String::from_utf8_unchecked(__v)
};
}
Some(ast::Type::BorrowedStr) |
Some(ast::Type::ByRef(_)) |
Some(ast::Type::ByMutRef(_)) => panic!("can't return a borrowed ref"),
Some(ast::Type::String) => panic!("can't return a string in foreign functions"),
Some(ast::Type::ByValue(_)) => panic!("can't return a struct in a foreign function"),
None => {
abi_ret = my_quote! { () };
convert_ret = my_quote! {};