mirror of
https://github.com/fluencelabs/wasm-bindgen
synced 2025-06-16 14:31:22 +00:00
Overhaul the conversion traits
This commit overhauls the conversion traits used for types crossing the Rust/JS boundary. Previously there were a few ad-hoc traits but now there've been slightly reduced and decoupled. Conversion from Rust values to JS values is now exclusively done through `IntoWasmAbi` with no special treatment for references. Conversion from JS to Rust is a bit trickier as we want to create references in Rust which have implications in terms of safety. As a result there are now three traits for this, `FromWasmAbi`, `RefFromWasmAbi`, and `RefMutFromWasmAbi`. These three traits are implemented for various types and specially dispatched to depending on the type of argument in the code generator. The goal of this commit is to lay the groundwork for using these traits in closures with straightforward-ish definitions.
This commit is contained in:
Alex Crichton
@ -116,7 +116,7 @@ impl ToTokens for ast::Struct {
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}
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}
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impl ::wasm_bindgen::convert::WasmBoundary for #name {
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impl ::wasm_bindgen::convert::IntoWasmAbi for #name {
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type Abi = u32;
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fn into_abi(self, _extra: &mut ::wasm_bindgen::convert::Stack)
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@ -124,40 +124,44 @@ impl ToTokens for ast::Struct {
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{
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Box::into_raw(Box::new(::wasm_bindgen::__rt::WasmRefCell::new(self))) as u32
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}
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}
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unsafe fn from_abi(js: u32, _extra: &mut ::wasm_bindgen::convert::Stack)
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impl ::wasm_bindgen::convert::FromWasmAbi for #name {
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type Abi = u32;
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unsafe fn from_abi(js: u32, extra: &mut ::wasm_bindgen::convert::Stack)
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-> Self
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{
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let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
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::wasm_bindgen::__rt::assert_not_null(js);
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let js = Box::from_raw(js);
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let ptr = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
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::wasm_bindgen::__rt::assert_not_null(ptr);
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let js = Box::from_raw(ptr);
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js.borrow_mut(); // make sure no one's borrowing
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js.into_inner()
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}
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}
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impl ::wasm_bindgen::convert::FromRefWasmBoundary for #name {
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impl ::wasm_bindgen::convert::RefFromWasmAbi for #name {
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type Abi = u32;
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type RefAnchor = ::wasm_bindgen::__rt::Ref<'static, #name>;
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type Anchor = ::wasm_bindgen::__rt::Ref<'static, #name>;
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unsafe fn from_abi_ref(
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unsafe fn ref_from_abi(
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js: Self::Abi,
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_extra: &mut ::wasm_bindgen::convert::Stack,
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) -> Self::RefAnchor {
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) -> Self::Anchor {
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let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
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::wasm_bindgen::__rt::assert_not_null(js);
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(*js).borrow()
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}
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}
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impl ::wasm_bindgen::convert::FromRefMutWasmBoundary for #name {
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impl ::wasm_bindgen::convert::RefMutFromWasmAbi for #name {
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type Abi = u32;
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type RefAnchor = ::wasm_bindgen::__rt::RefMut<'static, #name>;
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type Anchor = ::wasm_bindgen::__rt::RefMut<'static, #name>;
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unsafe fn from_abi_ref_mut(
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unsafe fn ref_mut_from_abi(
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js: Self::Abi,
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_extra: &mut ::wasm_bindgen::convert::Stack,
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) -> Self::RefAnchor {
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) -> Self::Anchor {
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let js = js as *mut ::wasm_bindgen::__rt::WasmRefCell<#name>;
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::wasm_bindgen::__rt::assert_not_null(js);
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(*js).borrow_mut()
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@ -166,7 +170,7 @@ impl ToTokens for ast::Struct {
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impl ::std::convert::From<#name> for ::wasm_bindgen::JsValue {
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fn from(value: #name) -> Self {
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let ptr = ::wasm_bindgen::convert::WasmBoundary::into_abi(
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let ptr = ::wasm_bindgen::convert::IntoWasmAbi::into_abi(
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value,
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unsafe { &mut ::wasm_bindgen::convert::GlobalStack::new() },
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);
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@ -177,7 +181,7 @@ impl ToTokens for ast::Struct {
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}
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unsafe {
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<::wasm_bindgen::JsValue as ::wasm_bindgen::convert::WasmBoundary>
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<::wasm_bindgen::JsValue as ::wasm_bindgen::convert::FromWasmAbi>
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::from_abi(
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#new_fn(ptr),
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&mut ::wasm_bindgen::convert::GlobalStack::new(),
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@ -188,7 +192,7 @@ impl ToTokens for ast::Struct {
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#[no_mangle]
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pub unsafe extern fn #free_fn(ptr: u32) {
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<#name as ::wasm_bindgen::convert::WasmBoundary>::from_abi(
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<#name as ::wasm_bindgen::convert::FromWasmAbi>::from_abi(
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ptr,
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&mut ::wasm_bindgen::convert::GlobalStack::new(),
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);
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@ -220,41 +224,44 @@ impl ToTokens for ast::Export {
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for (i, ty) in self.function.arguments.iter().enumerate() {
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let i = i + offset;
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let ident = syn::Ident::from(format!("arg{}", i));
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let t = &ty.ty;
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match ty.kind {
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ast::TypeKind::ByValue => {
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match *ty {
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syn::Type::Reference(syn::TypeReference {
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mutability: Some(_),
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ref elem,
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..
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}) => {
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args.push(quote! {
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#ident: <#t as ::wasm_bindgen::convert::WasmBoundary>::Abi
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#ident: <#elem as ::wasm_bindgen::convert::RefMutFromWasmAbi>::Abi
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});
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arg_conversions.push(quote! {
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let #ident = unsafe {
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<#t as ::wasm_bindgen::convert::WasmBoundary>
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::from_abi(#ident, &mut __stack)
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let mut #ident = unsafe {
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<#elem as ::wasm_bindgen::convert::RefMutFromWasmAbi>
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::ref_mut_from_abi(#ident, &mut __stack)
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};
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let #ident = &mut *#ident;
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});
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}
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ast::TypeKind::ByRef => {
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syn::Type::Reference(syn::TypeReference { ref elem, .. }) => {
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args.push(quote! {
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#ident: <#t as ::wasm_bindgen::convert::FromRefWasmBoundary>::Abi
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#ident: <#elem as ::wasm_bindgen::convert::RefFromWasmAbi>::Abi
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});
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arg_conversions.push(quote! {
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let #ident = unsafe {
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<#t as ::wasm_bindgen::convert::FromRefWasmBoundary>
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::from_abi_ref(#ident, &mut __stack)
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<#elem as ::wasm_bindgen::convert::RefFromWasmAbi>
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::ref_from_abi(#ident, &mut __stack)
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};
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let #ident = &*#ident;
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});
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}
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ast::TypeKind::ByMutRef => {
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_ => {
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args.push(quote! {
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#ident: <#t as ::wasm_bindgen::convert::FromRefMutWasmBoundary>::Abi
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#ident: <#ty as ::wasm_bindgen::convert::FromWasmAbi>::Abi
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});
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arg_conversions.push(quote! {
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let mut #ident = unsafe {
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<#t as ::wasm_bindgen::convert::FromRefMutWasmBoundary>
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::from_abi_ref_mut(#ident, &mut __stack)
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let #ident = unsafe {
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<#ty as ::wasm_bindgen::convert::FromWasmAbi>
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::from_abi(#ident, &mut __stack)
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};
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let #ident = &mut *#ident;
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});
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}
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}
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@ -263,28 +270,25 @@ impl ToTokens for ast::Export {
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let ret_ty;
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let convert_ret;
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match self.function.ret {
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Some(ast::Type { ref ty, kind: ast::TypeKind::ByValue, .. }) => {
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Some(syn::Type::Reference(_)) => panic!("can't return a borrowed ref"),
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Some(ref ty) => {
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ret_ty = quote! {
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-> <#ty as ::wasm_bindgen::convert::WasmBoundary>::Abi
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-> <#ty as ::wasm_bindgen::convert::IntoWasmAbi>::Abi
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};
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convert_ret = quote! {
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<#ty as ::wasm_bindgen::convert::WasmBoundary>
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<#ty as ::wasm_bindgen::convert::IntoWasmAbi>
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::into_abi(#ret, &mut unsafe {
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::wasm_bindgen::convert::GlobalStack::new()
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})
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};
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}
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Some(ast::Type { kind: ast::TypeKind::ByMutRef, .. }) |
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Some(ast::Type { kind: ast::TypeKind::ByRef, .. }) => {
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panic!("can't return a borrowed ref");
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}
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None => {
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ret_ty = quote!{};
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convert_ret = quote!{};
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}
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}
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let describe_ret = match self.function.ret {
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Some(ast::Type { ref ty, .. }) => {
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Some(ref ty) => {
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quote! {
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inform(1);
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<#ty as WasmDescribe>::describe();
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@ -380,47 +384,55 @@ impl ToTokens for ast::ImportType {
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}
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}
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impl ::wasm_bindgen::convert::WasmBoundary for #name {
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impl ::wasm_bindgen::convert::IntoWasmAbi for #name {
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type Abi = <::wasm_bindgen::JsValue as
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::wasm_bindgen::convert::WasmBoundary>::Abi;
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::wasm_bindgen::convert::IntoWasmAbi>::Abi;
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fn into_abi(self, extra: &mut ::wasm_bindgen::convert::Stack) -> Self::Abi {
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self.obj.into_abi(extra)
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}
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}
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impl ::wasm_bindgen::convert::FromWasmAbi for #name {
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type Abi = <::wasm_bindgen::JsValue as
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::wasm_bindgen::convert::FromWasmAbi>::Abi;
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unsafe fn from_abi(
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js: Self::Abi,
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extra: &mut ::wasm_bindgen::convert::Stack,
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) -> Self {
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#name { obj: ::wasm_bindgen::JsValue::from_abi(js, extra) }
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#name {
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obj: ::wasm_bindgen::JsValue::from_abi(js, extra),
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}
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}
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}
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impl ::wasm_bindgen::convert::ToRefWasmBoundary for #name {
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type Abi = <::wasm_bindgen::JsValue as
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::wasm_bindgen::convert::ToRefWasmBoundary>::Abi;
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impl<'a> ::wasm_bindgen::convert::IntoWasmAbi for &'a #name {
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type Abi = <&'a ::wasm_bindgen::JsValue as
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::wasm_bindgen::convert::IntoWasmAbi>::Abi;
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fn to_abi_ref(&self, extra: &mut ::wasm_bindgen::convert::Stack) -> u32 {
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self.obj.to_abi_ref(extra)
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fn into_abi(self, extra: &mut ::wasm_bindgen::convert::Stack) -> Self::Abi {
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(&self.obj).into_abi(extra)
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}
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}
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impl ::wasm_bindgen::convert::FromRefWasmBoundary for #name {
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impl ::wasm_bindgen::convert::RefFromWasmAbi for #name {
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type Abi = <::wasm_bindgen::JsValue as
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::wasm_bindgen::convert::ToRefWasmBoundary>::Abi;
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type RefAnchor = ::std::mem::ManuallyDrop<#name>;
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::wasm_bindgen::convert::RefFromWasmAbi>::Abi;
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type Anchor = ::std::mem::ManuallyDrop<#name>;
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unsafe fn from_abi_ref(
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unsafe fn ref_from_abi(
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js: Self::Abi,
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extra: &mut ::wasm_bindgen::convert::Stack,
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) -> Self::RefAnchor {
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let obj = <::wasm_bindgen::JsValue as ::wasm_bindgen::convert::WasmBoundary>
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::from_abi(js, extra);
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::std::mem::ManuallyDrop::new(#name { obj })
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) -> Self::Anchor {
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let tmp = <::wasm_bindgen::JsValue as ::wasm_bindgen::convert::RefFromWasmAbi>
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::ref_from_abi(js, extra);
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::std::mem::ManuallyDrop::new(#name {
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obj: ::std::mem::ManuallyDrop::into_inner(tmp),
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})
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}
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}
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impl From<::wasm_bindgen::JsValue> for #name {
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fn from(obj: ::wasm_bindgen::JsValue) -> #name {
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#name { obj }
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@ -478,65 +490,38 @@ impl ToTokens for ast::ImportFunction {
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});
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for (i, (ty, name)) in self.function.arguments.iter().zip(names).enumerate() {
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let t = &ty.ty;
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match ty.kind {
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ast::TypeKind::ByValue => {
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abi_argument_names.push(name);
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abi_arguments.push(quote! {
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#name: <#t as ::wasm_bindgen::convert::WasmBoundary>::Abi
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});
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let var = if i == 0 && is_method {
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quote! { self }
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} else {
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quote! { #name }
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};
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arg_conversions.push(quote! {
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let #name = <#t as ::wasm_bindgen::convert::WasmBoundary>
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::into_abi(#var, &mut __stack);
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});
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}
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ast::TypeKind::ByMutRef => {
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abi_argument_names.push(name);
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abi_arguments.push(quote! { #name: u32 });
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arg_conversions.push(quote! {
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let #name = <#t as ::wasm_bindgen::convert::ToRefMutWasmBoundary>
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::to_abi_ref_mut(#name, &mut __stack);
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});
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}
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ast::TypeKind::ByRef => {
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abi_argument_names.push(name);
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abi_arguments.push(quote! { #name: u32 });
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let var = if i == 0 && is_method {
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quote! { self }
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} else {
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quote! { #name }
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};
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arg_conversions.push(quote! {
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let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
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::to_abi_ref(#var, &mut __stack);
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});
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}
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}
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abi_argument_names.push(name);
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abi_arguments.push(quote! {
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#name: <#ty as ::wasm_bindgen::convert::IntoWasmAbi>::Abi
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});
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let var = if i == 0 && is_method {
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quote! { self }
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} else {
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quote! { #name }
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};
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arg_conversions.push(quote! {
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let #name = <#ty as ::wasm_bindgen::convert::IntoWasmAbi>
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::into_abi(#var, &mut __stack);
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});
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}
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let abi_ret;
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let mut convert_ret;
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match self.function.ret {
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Some(ast::Type { ref ty, kind: ast::TypeKind::ByValue, .. }) => {
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Some(syn::Type::Reference(_)) => {
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panic!("cannot return references in imports yet");
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}
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Some(ref ty) => {
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abi_ret = quote! {
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<#ty as ::wasm_bindgen::convert::WasmBoundary>::Abi
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<#ty as ::wasm_bindgen::convert::FromWasmAbi>::Abi
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};
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convert_ret = quote! {
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<#ty as ::wasm_bindgen::convert::WasmBoundary>
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<#ty as ::wasm_bindgen::convert::FromWasmAbi>
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::from_abi(
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#ret_ident,
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&mut ::wasm_bindgen::convert::GlobalStack::new(),
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)
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};
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}
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Some(ast::Type { kind: ast::TypeKind::ByRef, .. }) |
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Some(ast::Type { kind: ast::TypeKind::ByMutRef, .. }) => {
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panic!("can't return a borrowed ref")
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}
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None => {
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abi_ret = quote! { () };
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convert_ret = quote! { () };
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@ -554,8 +539,8 @@ impl ToTokens for ast::ImportFunction {
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if #exn_data[0] == 1 {
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return Err(
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<
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::wasm_bindgen::JsValue as ::wasm_bindgen::convert::WasmBoundary
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>::from_abi(#exn_data[1], &mut ::wasm_bindgen::convert::GlobalStack::new()),
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::wasm_bindgen::JsValue as ::wasm_bindgen::convert::FromWasmAbi
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>::from_abi(#exn_data[1], &mut ::wasm_bindgen::convert::GlobalStack::new())
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)
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}
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};
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@ -663,12 +648,16 @@ impl ToTokens for ast::Enum {
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}
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});
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(quote! {
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impl ::wasm_bindgen::convert::WasmBoundary for #enum_name {
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impl ::wasm_bindgen::convert::IntoWasmAbi for #enum_name {
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type Abi = u32;
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|
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fn into_abi(self, _extra: &mut ::wasm_bindgen::convert::Stack) -> u32 {
|
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self as u32
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}
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}
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impl ::wasm_bindgen::convert::FromWasmAbi for #enum_name {
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type Abi = u32;
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unsafe fn from_abi(
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js: u32,
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@ -702,13 +691,14 @@ impl ToTokens for ast::ImportStatic {
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fn init() -> #ty {
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#[wasm_import_module = "__wbindgen_placeholder__"]
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extern {
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fn #shim_name() -> <#ty as ::wasm_bindgen::convert::WasmBoundary>::Abi;
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fn #shim_name() -> <#ty as ::wasm_bindgen::convert::FromWasmAbi>::Abi;
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}
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unsafe {
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::wasm_bindgen::convert::WasmBoundary::from_abi(
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<#ty as ::wasm_bindgen::convert::FromWasmAbi>::from_abi(
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#shim_name(),
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&mut ::wasm_bindgen::convert::GlobalStack::new(),
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)
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}
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}
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::wasm_bindgen::JsStatic {
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@ -719,19 +709,3 @@ impl ToTokens for ast::ImportStatic {
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}).to_tokens(into);
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}
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}
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impl ToTokens for ast::Type {
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fn to_tokens(&self, into: &mut Tokens) {
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match self.kind {
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ast::TypeKind::ByValue => {}
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ast::TypeKind::ByRef => {
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syn::token::And::default().to_tokens(into);
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}
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ast::TypeKind::ByMutRef => {
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syn::token::And::default().to_tokens(into);
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syn::token::Mut::default().to_tokens(into);
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}
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}
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self.ty.to_tokens(into);
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}
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}
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Reference in New Issue
Block a user