| use crate::ast; |
| use crate::encode; |
| use crate::Diagnostic; |
| use once_cell::sync::Lazy; |
| use proc_macro2::{Ident, Literal, Span, TokenStream}; |
| use quote::{quote, ToTokens}; |
| use std::collections::{HashMap, HashSet}; |
| use std::sync::Mutex; |
| use wasm_bindgen_shared as shared; |
| |
| /// A trait for converting AST structs into Tokens and adding them to a TokenStream, |
| /// or providing a diagnostic if conversion fails. |
| pub trait TryToTokens { |
| /// Attempt to convert a `Self` into tokens and add it to the `TokenStream` |
| fn try_to_tokens(&self, tokens: &mut TokenStream) -> Result<(), Diagnostic>; |
| |
| /// Attempt to convert a `Self` into a new `TokenStream` |
| fn try_to_token_stream(&self) -> Result<TokenStream, Diagnostic> { |
| let mut tokens = TokenStream::new(); |
| self.try_to_tokens(&mut tokens)?; |
| Ok(tokens) |
| } |
| } |
| |
| impl TryToTokens for ast::Program { |
| // Generate wrappers for all the items that we've found |
| fn try_to_tokens(&self, tokens: &mut TokenStream) -> Result<(), Diagnostic> { |
| let mut errors = Vec::new(); |
| for export in self.exports.iter() { |
| if let Err(e) = export.try_to_tokens(tokens) { |
| errors.push(e); |
| } |
| } |
| for s in self.structs.iter() { |
| s.to_tokens(tokens); |
| } |
| let mut types = HashMap::new(); |
| for i in self.imports.iter() { |
| if let ast::ImportKind::Type(t) = &i.kind { |
| types.insert(t.rust_name.to_string(), t.rust_name.clone()); |
| } |
| } |
| for i in self.imports.iter() { |
| DescribeImport { kind: &i.kind }.to_tokens(tokens); |
| |
| // If there is a js namespace, check that name isn't a type. If it is, |
| // this import might be a method on that type. |
| if let Some(nss) = &i.js_namespace { |
| // When the namespace is `A.B`, the type name should be `B`. |
| if let Some(ns) = nss.last().and_then(|t| types.get(t)) { |
| if i.kind.fits_on_impl() { |
| let kind = match i.kind.try_to_token_stream() { |
| Ok(kind) => kind, |
| Err(e) => { |
| errors.push(e); |
| continue; |
| } |
| }; |
| (quote! { |
| #[automatically_derived] |
| impl #ns { #kind } |
| }) |
| .to_tokens(tokens); |
| continue; |
| } |
| } |
| } |
| |
| if let Err(e) = i.kind.try_to_tokens(tokens) { |
| errors.push(e); |
| } |
| } |
| for e in self.enums.iter() { |
| e.to_tokens(tokens); |
| } |
| |
| Diagnostic::from_vec(errors)?; |
| |
| // Generate a static which will eventually be what lives in a custom section |
| // of the wasm executable. For now it's just a plain old static, but we'll |
| // eventually have it actually in its own section. |
| |
| // See comments in `crates/cli-support/src/lib.rs` about what this |
| // `schema_version` is. |
| let prefix_json = format!( |
| r#"{{"schema_version":"{}","version":"{}"}}"#, |
| shared::SCHEMA_VERSION, |
| shared::version() |
| ); |
| let encoded = encode::encode(self)?; |
| let len = prefix_json.len() as u32; |
| let bytes = [ |
| &len.to_le_bytes()[..], |
| prefix_json.as_bytes(), |
| &encoded.custom_section, |
| ] |
| .concat(); |
| |
| let generated_static_length = bytes.len(); |
| let generated_static_value = syn::LitByteStr::new(&bytes, Span::call_site()); |
| |
| // We already consumed the contents of included files when generating |
| // the custom section, but we want to make sure that updates to the |
| // generated files will cause this macro to rerun incrementally. To do |
| // that we use `include_str!` to force rustc to think it has a |
| // dependency on these files. That way when the file changes Cargo will |
| // automatically rerun rustc which will rerun this macro. Other than |
| // this we don't actually need the results of the `include_str!`, so |
| // it's just shoved into an anonymous static. |
| let file_dependencies = encoded.included_files.iter().map(|file| { |
| let file = file.to_str().unwrap(); |
| quote! { include_str!(#file) } |
| }); |
| |
| (quote! { |
| #[cfg(target_arch = "wasm32")] |
| #[automatically_derived] |
| const _: () = { |
| static _INCLUDED_FILES: &[&str] = &[#(#file_dependencies),*]; |
| |
| #[link_section = "__wasm_bindgen_unstable"] |
| pub static _GENERATED: [u8; #generated_static_length] = |
| *#generated_static_value; |
| }; |
| }) |
| .to_tokens(tokens); |
| |
| Ok(()) |
| } |
| } |
| |
| impl TryToTokens for ast::LinkToModule { |
| fn try_to_tokens(&self, tokens: &mut TokenStream) -> Result<(), Diagnostic> { |
| let mut program = TokenStream::new(); |
| self.0.try_to_tokens(&mut program)?; |
| let link_function_name = self.0.link_function_name(0); |
| let name = Ident::new(&link_function_name, Span::call_site()); |
| let abi_ret = quote! { <std::string::String as wasm_bindgen::convert::FromWasmAbi>::Abi }; |
| let extern_fn = extern_fn(&name, &[], &[], &[], abi_ret); |
| (quote! { |
| { |
| #program |
| #extern_fn |
| |
| unsafe { |
| <std::string::String as wasm_bindgen::convert::FromWasmAbi>::from_abi(#name()) |
| } |
| } |
| }) |
| .to_tokens(tokens); |
| Ok(()) |
| } |
| } |
| |
| impl ToTokens for ast::Struct { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| let name = &self.rust_name; |
| let name_str = self.js_name.to_string(); |
| let name_len = name_str.len() as u32; |
| let name_chars = name_str.chars().map(|c| c as u32); |
| let new_fn = Ident::new(&shared::new_function(&name_str), Span::call_site()); |
| let free_fn = Ident::new(&shared::free_function(&name_str), Span::call_site()); |
| (quote! { |
| #[automatically_derived] |
| impl wasm_bindgen::describe::WasmDescribe for #name { |
| fn describe() { |
| use wasm_bindgen::__wbindgen_if_not_std; |
| __wbindgen_if_not_std! { |
| compile_error! { |
| "exporting a class to JS requires the `std` feature to \ |
| be enabled in the `wasm-bindgen` crate" |
| } |
| } |
| use wasm_bindgen::describe::*; |
| inform(RUST_STRUCT); |
| inform(#name_len); |
| #(inform(#name_chars);)* |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::IntoWasmAbi for #name { |
| type Abi = u32; |
| |
| fn into_abi(self) -> u32 { |
| use wasm_bindgen::__rt::std::boxed::Box; |
| use wasm_bindgen::__rt::WasmRefCell; |
| Box::into_raw(Box::new(WasmRefCell::new(self))) as u32 |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::FromWasmAbi for #name { |
| type Abi = u32; |
| |
| unsafe fn from_abi(js: u32) -> Self { |
| use wasm_bindgen::__rt::std::boxed::Box; |
| use wasm_bindgen::__rt::{assert_not_null, WasmRefCell}; |
| |
| let ptr = js as *mut WasmRefCell<#name>; |
| assert_not_null(ptr); |
| let js = Box::from_raw(ptr); |
| (*js).borrow_mut(); // make sure no one's borrowing |
| js.into_inner() |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::__rt::core::convert::From<#name> for |
| wasm_bindgen::JsValue |
| { |
| fn from(value: #name) -> Self { |
| let ptr = wasm_bindgen::convert::IntoWasmAbi::into_abi(value); |
| |
| #[link(wasm_import_module = "__wbindgen_placeholder__")] |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| extern "C" { |
| fn #new_fn(ptr: u32) -> u32; |
| } |
| |
| #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))] |
| unsafe fn #new_fn(_: u32) -> u32 { |
| panic!("cannot convert to JsValue outside of the wasm target") |
| } |
| |
| unsafe { |
| <wasm_bindgen::JsValue as wasm_bindgen::convert::FromWasmAbi> |
| ::from_abi(#new_fn(ptr)) |
| } |
| } |
| } |
| |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| #[automatically_derived] |
| const _: () = { |
| #[no_mangle] |
| #[doc(hidden)] |
| pub unsafe extern "C" fn #free_fn(ptr: u32) { |
| let _ = <#name as wasm_bindgen::convert::FromWasmAbi>::from_abi(ptr); //implicit `drop()` |
| } |
| }; |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::RefFromWasmAbi for #name { |
| type Abi = u32; |
| type Anchor = wasm_bindgen::__rt::Ref<'static, #name>; |
| |
| unsafe fn ref_from_abi(js: Self::Abi) -> Self::Anchor { |
| let js = js as *mut wasm_bindgen::__rt::WasmRefCell<#name>; |
| wasm_bindgen::__rt::assert_not_null(js); |
| (*js).borrow() |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::RefMutFromWasmAbi for #name { |
| type Abi = u32; |
| type Anchor = wasm_bindgen::__rt::RefMut<'static, #name>; |
| |
| unsafe fn ref_mut_from_abi(js: Self::Abi) -> Self::Anchor { |
| let js = js as *mut wasm_bindgen::__rt::WasmRefCell<#name>; |
| wasm_bindgen::__rt::assert_not_null(js); |
| (*js).borrow_mut() |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::LongRefFromWasmAbi for #name { |
| type Abi = u32; |
| type Anchor = wasm_bindgen::__rt::Ref<'static, #name>; |
| |
| unsafe fn long_ref_from_abi(js: Self::Abi) -> Self::Anchor { |
| <Self as wasm_bindgen::convert::RefFromWasmAbi>::ref_from_abi(js) |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionIntoWasmAbi for #name { |
| #[inline] |
| fn none() -> Self::Abi { 0 } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionFromWasmAbi for #name { |
| #[inline] |
| fn is_none(abi: &Self::Abi) -> bool { *abi == 0 } |
| } |
| }) |
| .to_tokens(tokens); |
| |
| for field in self.fields.iter() { |
| field.to_tokens(tokens); |
| } |
| } |
| } |
| |
| impl ToTokens for ast::StructField { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| let rust_name = &self.rust_name; |
| let struct_name = &self.struct_name; |
| let ty = &self.ty; |
| let getter = &self.getter; |
| let setter = &self.setter; |
| |
| let maybe_assert_copy = if self.getter_with_clone { |
| quote! {} |
| } else { |
| quote! { assert_copy::<#ty>() } |
| }; |
| let maybe_assert_copy = respan(maybe_assert_copy, ty); |
| |
| let maybe_clone = if self.getter_with_clone { |
| quote! { .clone() } |
| } else { |
| quote! {} |
| }; |
| |
| (quote! { |
| #[automatically_derived] |
| const _: () = { |
| #[cfg_attr(all(target_arch = "wasm32", not(target_os = "emscripten")), no_mangle)] |
| #[doc(hidden)] |
| pub unsafe extern "C" fn #getter(js: u32) |
| -> <#ty as wasm_bindgen::convert::IntoWasmAbi>::Abi |
| { |
| use wasm_bindgen::__rt::{WasmRefCell, assert_not_null}; |
| use wasm_bindgen::convert::IntoWasmAbi; |
| |
| fn assert_copy<T: Copy>(){} |
| #maybe_assert_copy; |
| |
| let js = js as *mut WasmRefCell<#struct_name>; |
| assert_not_null(js); |
| let val = (*js).borrow().#rust_name#maybe_clone; |
| <#ty as IntoWasmAbi>::into_abi(val) |
| } |
| }; |
| }) |
| .to_tokens(tokens); |
| |
| Descriptor { |
| ident: &getter, |
| inner: quote! { |
| <#ty as WasmDescribe>::describe(); |
| }, |
| attrs: vec![], |
| } |
| .to_tokens(tokens); |
| |
| if self.readonly { |
| return; |
| } |
| |
| (quote! { |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| #[automatically_derived] |
| const _: () = { |
| #[no_mangle] |
| #[doc(hidden)] |
| pub unsafe extern "C" fn #setter( |
| js: u32, |
| val: <#ty as wasm_bindgen::convert::FromWasmAbi>::Abi, |
| ) { |
| use wasm_bindgen::__rt::{WasmRefCell, assert_not_null}; |
| use wasm_bindgen::convert::FromWasmAbi; |
| |
| let js = js as *mut WasmRefCell<#struct_name>; |
| assert_not_null(js); |
| let val = <#ty as FromWasmAbi>::from_abi(val); |
| (*js).borrow_mut().#rust_name = val; |
| } |
| }; |
| }) |
| .to_tokens(tokens); |
| } |
| } |
| |
| impl TryToTokens for ast::Export { |
| fn try_to_tokens(self: &ast::Export, into: &mut TokenStream) -> Result<(), Diagnostic> { |
| let generated_name = self.rust_symbol(); |
| let export_name = self.export_name(); |
| let mut args = vec![]; |
| let mut arg_conversions = vec![]; |
| let mut converted_arguments = vec![]; |
| let ret = Ident::new("_ret", Span::call_site()); |
| |
| let offset = if self.method_self.is_some() { |
| args.push(quote! { me: u32 }); |
| 1 |
| } else { |
| 0 |
| }; |
| |
| let name = &self.rust_name; |
| let receiver = match self.method_self { |
| Some(ast::MethodSelf::ByValue) => { |
| let class = self.rust_class.as_ref().unwrap(); |
| arg_conversions.push(quote! { |
| let me = unsafe { |
| <#class as wasm_bindgen::convert::FromWasmAbi>::from_abi(me) |
| }; |
| }); |
| quote! { me.#name } |
| } |
| Some(ast::MethodSelf::RefMutable) => { |
| let class = self.rust_class.as_ref().unwrap(); |
| arg_conversions.push(quote! { |
| let mut me = unsafe { |
| <#class as wasm_bindgen::convert::RefMutFromWasmAbi> |
| ::ref_mut_from_abi(me) |
| }; |
| let me = &mut *me; |
| }); |
| quote! { me.#name } |
| } |
| Some(ast::MethodSelf::RefShared) => { |
| let class = self.rust_class.as_ref().unwrap(); |
| arg_conversions.push(quote! { |
| let me = unsafe { |
| <#class as wasm_bindgen::convert::RefFromWasmAbi> |
| ::ref_from_abi(me) |
| }; |
| let me = &*me; |
| }); |
| quote! { me.#name } |
| } |
| None => match &self.rust_class { |
| Some(class) => quote! { #class::#name }, |
| None => quote! { #name }, |
| }, |
| }; |
| |
| let mut argtys = Vec::new(); |
| for (i, arg) in self.function.arguments.iter().enumerate() { |
| argtys.push(&*arg.ty); |
| let i = i + offset; |
| let ident = Ident::new(&format!("arg{}", i), Span::call_site()); |
| let ty = &arg.ty; |
| match &*arg.ty { |
| syn::Type::Reference(syn::TypeReference { |
| mutability: Some(_), |
| elem, |
| .. |
| }) => { |
| args.push(quote! { |
| #ident: <#elem as wasm_bindgen::convert::RefMutFromWasmAbi>::Abi |
| }); |
| arg_conversions.push(quote! { |
| let mut #ident = unsafe { |
| <#elem as wasm_bindgen::convert::RefMutFromWasmAbi> |
| ::ref_mut_from_abi(#ident) |
| }; |
| let #ident = &mut *#ident; |
| }); |
| } |
| syn::Type::Reference(syn::TypeReference { elem, .. }) => { |
| if self.function.r#async { |
| args.push(quote! { |
| #ident: <#elem as wasm_bindgen::convert::LongRefFromWasmAbi>::Abi |
| }); |
| arg_conversions.push(quote! { |
| let #ident = unsafe { |
| <#elem as wasm_bindgen::convert::LongRefFromWasmAbi> |
| ::long_ref_from_abi(#ident) |
| }; |
| let #ident = <<#elem as wasm_bindgen::convert::LongRefFromWasmAbi> |
| ::Anchor as core::borrow::Borrow<#elem>> |
| ::borrow(&#ident); |
| }); |
| } else { |
| args.push(quote! { |
| #ident: <#elem as wasm_bindgen::convert::RefFromWasmAbi>::Abi |
| }); |
| arg_conversions.push(quote! { |
| let #ident = unsafe { |
| <#elem as wasm_bindgen::convert::RefFromWasmAbi> |
| ::ref_from_abi(#ident) |
| }; |
| let #ident = &*#ident; |
| }); |
| } |
| } |
| _ => { |
| args.push(quote! { |
| #ident: <#ty as wasm_bindgen::convert::FromWasmAbi>::Abi |
| }); |
| arg_conversions.push(quote! { |
| let #ident = unsafe { |
| <#ty as wasm_bindgen::convert::FromWasmAbi> |
| ::from_abi(#ident) |
| }; |
| }); |
| } |
| } |
| converted_arguments.push(quote! { #ident }); |
| } |
| let syn_unit = syn::Type::Tuple(syn::TypeTuple { |
| elems: Default::default(), |
| paren_token: Default::default(), |
| }); |
| let syn_ret = self.function.ret.as_ref().unwrap_or(&syn_unit); |
| if let syn::Type::Reference(_) = syn_ret { |
| bail_span!(syn_ret, "cannot return a borrowed ref with #[wasm_bindgen]",) |
| } |
| |
| // For an `async` function we always run it through `future_to_promise` |
| // since we're returning a promise to JS, and this will implicitly |
| // require that the function returns a `Future<Output = Result<...>>` |
| let (ret_ty, inner_ret_ty, ret_expr) = if self.function.r#async { |
| if self.start { |
| ( |
| quote! { () }, |
| quote! { () }, |
| quote! { |
| <#syn_ret as wasm_bindgen::__rt::Start>::start(#ret.await) |
| }, |
| ) |
| } else { |
| ( |
| quote! { wasm_bindgen::JsValue }, |
| quote! { #syn_ret }, |
| quote! { |
| <#syn_ret as wasm_bindgen::__rt::IntoJsResult>::into_js_result(#ret.await) |
| }, |
| ) |
| } |
| } else if self.start { |
| ( |
| quote! { () }, |
| quote! { () }, |
| quote! { <#syn_ret as wasm_bindgen::__rt::Start>::start(#ret) }, |
| ) |
| } else { |
| (quote! { #syn_ret }, quote! { #syn_ret }, quote! { #ret }) |
| }; |
| |
| let mut call = quote! { |
| { |
| #(#arg_conversions)* |
| let #ret = #receiver(#(#converted_arguments),*); |
| #ret_expr |
| } |
| }; |
| |
| if self.function.r#async { |
| if self.start { |
| call = quote! { |
| wasm_bindgen_futures::spawn_local(async move { |
| #call |
| }) |
| } |
| } else { |
| call = quote! { |
| wasm_bindgen_futures::future_to_promise(async move { |
| #call |
| }).into() |
| } |
| } |
| } |
| |
| let projection = quote! { <#ret_ty as wasm_bindgen::convert::ReturnWasmAbi> }; |
| let convert_ret = quote! { #projection::return_abi(#ret) }; |
| let describe_ret = quote! { |
| <#ret_ty as WasmDescribe>::describe(); |
| <#inner_ret_ty as WasmDescribe>::describe(); |
| }; |
| let nargs = self.function.arguments.len() as u32; |
| let attrs = &self.function.rust_attrs; |
| |
| let start_check = if self.start { |
| quote! { const _ASSERT: fn() = || -> #projection::Abi { loop {} }; } |
| } else { |
| quote! {} |
| }; |
| |
| (quote! { |
| #[automatically_derived] |
| const _: () = { |
| #(#attrs)* |
| #[cfg_attr( |
| all(target_arch = "wasm32", not(target_os = "emscripten")), |
| export_name = #export_name, |
| )] |
| pub unsafe extern "C" fn #generated_name(#(#args),*) -> #projection::Abi { |
| #start_check |
| |
| let #ret = #call; |
| #convert_ret |
| } |
| }; |
| }) |
| .to_tokens(into); |
| |
| let describe_args: TokenStream = argtys |
| .iter() |
| .map(|ty| match ty { |
| syn::Type::Reference(reference) |
| if self.function.r#async && reference.mutability.is_none() => |
| { |
| let inner = &reference.elem; |
| quote! { |
| inform(LONGREF); |
| <#inner as WasmDescribe>::describe(); |
| } |
| } |
| _ => quote! { <#ty as WasmDescribe>::describe(); }, |
| }) |
| .collect(); |
| |
| // In addition to generating the shim function above which is what |
| // our generated JS will invoke, we *also* generate a "descriptor" |
| // shim. This descriptor shim uses the `WasmDescribe` trait to |
| // programmatically describe the type signature of the generated |
| // shim above. This in turn is then used to inform the |
| // `wasm-bindgen` CLI tool exactly what types and such it should be |
| // using in JS. |
| // |
| // Note that this descriptor function is a purely an internal detail |
| // of `#[wasm_bindgen]` and isn't intended to be exported to anyone |
| // or actually part of the final was binary. Additionally, this is |
| // literally executed when the `wasm-bindgen` tool executes. |
| // |
| // In any case, there's complications in `wasm-bindgen` to handle |
| // this, but the tl;dr; is that this is stripped from the final wasm |
| // binary along with anything it references. |
| let export = Ident::new(&export_name, Span::call_site()); |
| Descriptor { |
| ident: &export, |
| inner: quote! { |
| inform(FUNCTION); |
| inform(0); |
| inform(#nargs); |
| #describe_args |
| #describe_ret |
| }, |
| attrs: attrs.clone(), |
| } |
| .to_tokens(into); |
| |
| Ok(()) |
| } |
| } |
| |
| impl TryToTokens for ast::ImportKind { |
| fn try_to_tokens(&self, tokens: &mut TokenStream) -> Result<(), Diagnostic> { |
| match *self { |
| ast::ImportKind::Function(ref f) => f.try_to_tokens(tokens)?, |
| ast::ImportKind::Static(ref s) => s.to_tokens(tokens), |
| ast::ImportKind::Type(ref t) => t.to_tokens(tokens), |
| ast::ImportKind::Enum(ref e) => e.to_tokens(tokens), |
| } |
| |
| Ok(()) |
| } |
| } |
| |
| impl ToTokens for ast::ImportType { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| let vis = &self.vis; |
| let rust_name = &self.rust_name; |
| let attrs = &self.attrs; |
| let doc_comment = match &self.doc_comment { |
| None => "", |
| Some(comment) => comment, |
| }; |
| let instanceof_shim = Ident::new(&self.instanceof_shim, Span::call_site()); |
| |
| let internal_obj = match self.extends.first() { |
| Some(target) => { |
| quote! { #target } |
| } |
| None => { |
| quote! { wasm_bindgen::JsValue } |
| } |
| }; |
| |
| let description = if let Some(typescript_type) = &self.typescript_type { |
| let typescript_type_len = typescript_type.len() as u32; |
| let typescript_type_chars = typescript_type.chars().map(|c| c as u32); |
| quote! { |
| use wasm_bindgen::describe::*; |
| inform(NAMED_EXTERNREF); |
| inform(#typescript_type_len); |
| #(inform(#typescript_type_chars);)* |
| } |
| } else { |
| quote! { |
| JsValue::describe() |
| } |
| }; |
| |
| let is_type_of = self.is_type_of.as_ref().map(|is_type_of| { |
| quote! { |
| #[inline] |
| fn is_type_of(val: &JsValue) -> bool { |
| let is_type_of: fn(&JsValue) -> bool = #is_type_of; |
| is_type_of(val) |
| } |
| } |
| }); |
| |
| let no_deref = self.no_deref; |
| |
| (quote! { |
| #[automatically_derived] |
| #(#attrs)* |
| #[doc = #doc_comment] |
| #[repr(transparent)] |
| #vis struct #rust_name { |
| obj: #internal_obj |
| } |
| |
| #[automatically_derived] |
| const _: () = { |
| use wasm_bindgen::convert::{IntoWasmAbi, FromWasmAbi}; |
| use wasm_bindgen::convert::{OptionIntoWasmAbi, OptionFromWasmAbi}; |
| use wasm_bindgen::convert::{RefFromWasmAbi, LongRefFromWasmAbi}; |
| use wasm_bindgen::describe::WasmDescribe; |
| use wasm_bindgen::{JsValue, JsCast, JsObject}; |
| use wasm_bindgen::__rt::core; |
| |
| impl WasmDescribe for #rust_name { |
| fn describe() { |
| #description |
| } |
| } |
| |
| impl IntoWasmAbi for #rust_name { |
| type Abi = <JsValue as IntoWasmAbi>::Abi; |
| |
| #[inline] |
| fn into_abi(self) -> Self::Abi { |
| self.obj.into_abi() |
| } |
| } |
| |
| impl OptionIntoWasmAbi for #rust_name { |
| #[inline] |
| fn none() -> Self::Abi { |
| 0 |
| } |
| } |
| |
| impl<'a> OptionIntoWasmAbi for &'a #rust_name { |
| #[inline] |
| fn none() -> Self::Abi { |
| 0 |
| } |
| } |
| |
| impl FromWasmAbi for #rust_name { |
| type Abi = <JsValue as FromWasmAbi>::Abi; |
| |
| #[inline] |
| unsafe fn from_abi(js: Self::Abi) -> Self { |
| #rust_name { |
| obj: JsValue::from_abi(js).into(), |
| } |
| } |
| } |
| |
| impl OptionFromWasmAbi for #rust_name { |
| #[inline] |
| fn is_none(abi: &Self::Abi) -> bool { *abi == 0 } |
| } |
| |
| impl<'a> IntoWasmAbi for &'a #rust_name { |
| type Abi = <&'a JsValue as IntoWasmAbi>::Abi; |
| |
| #[inline] |
| fn into_abi(self) -> Self::Abi { |
| (&self.obj).into_abi() |
| } |
| } |
| |
| impl RefFromWasmAbi for #rust_name { |
| type Abi = <JsValue as RefFromWasmAbi>::Abi; |
| type Anchor = core::mem::ManuallyDrop<#rust_name>; |
| |
| #[inline] |
| unsafe fn ref_from_abi(js: Self::Abi) -> Self::Anchor { |
| let tmp = <JsValue as RefFromWasmAbi>::ref_from_abi(js); |
| core::mem::ManuallyDrop::new(#rust_name { |
| obj: core::mem::ManuallyDrop::into_inner(tmp).into(), |
| }) |
| } |
| } |
| |
| impl LongRefFromWasmAbi for #rust_name { |
| type Abi = <JsValue as LongRefFromWasmAbi>::Abi; |
| type Anchor = #rust_name; |
| |
| #[inline] |
| unsafe fn long_ref_from_abi(js: Self::Abi) -> Self::Anchor { |
| let tmp = <JsValue as LongRefFromWasmAbi>::long_ref_from_abi(js); |
| #rust_name { obj: tmp.into() } |
| } |
| } |
| |
| // TODO: remove this on the next major version |
| impl From<JsValue> for #rust_name { |
| #[inline] |
| fn from(obj: JsValue) -> #rust_name { |
| #rust_name { obj: obj.into() } |
| } |
| } |
| |
| impl AsRef<JsValue> for #rust_name { |
| #[inline] |
| fn as_ref(&self) -> &JsValue { self.obj.as_ref() } |
| } |
| |
| impl AsRef<#rust_name> for #rust_name { |
| #[inline] |
| fn as_ref(&self) -> &#rust_name { self } |
| } |
| |
| |
| impl From<#rust_name> for JsValue { |
| #[inline] |
| fn from(obj: #rust_name) -> JsValue { |
| obj.obj.into() |
| } |
| } |
| |
| impl JsCast for #rust_name { |
| fn instanceof(val: &JsValue) -> bool { |
| #[link(wasm_import_module = "__wbindgen_placeholder__")] |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| extern "C" { |
| fn #instanceof_shim(val: u32) -> u32; |
| } |
| #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))] |
| unsafe fn #instanceof_shim(_: u32) -> u32 { |
| panic!("cannot check instanceof on non-wasm targets"); |
| } |
| unsafe { |
| let idx = val.into_abi(); |
| #instanceof_shim(idx) != 0 |
| } |
| } |
| |
| #is_type_of |
| |
| #[inline] |
| fn unchecked_from_js(val: JsValue) -> Self { |
| #rust_name { obj: val.into() } |
| } |
| |
| #[inline] |
| fn unchecked_from_js_ref(val: &JsValue) -> &Self { |
| // Should be safe because `#rust_name` is a transparent |
| // wrapper around `val` |
| unsafe { &*(val as *const JsValue as *const #rust_name) } |
| } |
| } |
| |
| impl JsObject for #rust_name {} |
| }; |
| }) |
| .to_tokens(tokens); |
| |
| if !no_deref { |
| (quote! { |
| #[automatically_derived] |
| impl core::ops::Deref for #rust_name { |
| type Target = #internal_obj; |
| |
| #[inline] |
| fn deref(&self) -> &#internal_obj { |
| &self.obj |
| } |
| } |
| }) |
| .to_tokens(tokens); |
| } |
| |
| for superclass in self.extends.iter() { |
| (quote! { |
| #[automatically_derived] |
| impl From<#rust_name> for #superclass { |
| #[inline] |
| fn from(obj: #rust_name) -> #superclass { |
| use wasm_bindgen::JsCast; |
| #superclass::unchecked_from_js(obj.into()) |
| } |
| } |
| |
| #[automatically_derived] |
| impl AsRef<#superclass> for #rust_name { |
| #[inline] |
| fn as_ref(&self) -> &#superclass { |
| use wasm_bindgen::JsCast; |
| #superclass::unchecked_from_js_ref(self.as_ref()) |
| } |
| } |
| }) |
| .to_tokens(tokens); |
| } |
| } |
| } |
| |
| impl ToTokens for ast::ImportEnum { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| let vis = &self.vis; |
| let name = &self.name; |
| let expect_string = format!("attempted to convert invalid {} into JSValue", name); |
| let variants = &self.variants; |
| let variant_strings = &self.variant_values; |
| let attrs = &self.rust_attrs; |
| |
| let mut current_idx: usize = 0; |
| let variant_indexes: Vec<Literal> = variants |
| .iter() |
| .map(|_| { |
| let this_index = current_idx; |
| current_idx += 1; |
| Literal::usize_unsuffixed(this_index) |
| }) |
| .collect(); |
| |
| // Borrow variant_indexes because we need to use it multiple times inside the quote! macro |
| let variant_indexes_ref = &variant_indexes; |
| |
| // A vector of EnumName::VariantName tokens for this enum |
| let variant_paths: Vec<TokenStream> = self |
| .variants |
| .iter() |
| .map(|v| quote!(#name::#v).into_token_stream()) |
| .collect(); |
| |
| // Borrow variant_paths because we need to use it multiple times inside the quote! macro |
| let variant_paths_ref = &variant_paths; |
| |
| (quote! { |
| #(#attrs)* |
| #vis enum #name { |
| #(#variants = #variant_indexes_ref,)* |
| #[automatically_derived] |
| #[doc(hidden)] |
| __Nonexhaustive, |
| } |
| |
| #[automatically_derived] |
| impl #name { |
| fn from_str(s: &str) -> Option<#name> { |
| match s { |
| #(#variant_strings => Some(#variant_paths_ref),)* |
| _ => None, |
| } |
| } |
| |
| fn to_str(&self) -> &'static str { |
| match self { |
| #(#variant_paths_ref => #variant_strings,)* |
| #name::__Nonexhaustive => panic!(#expect_string), |
| } |
| } |
| |
| #vis fn from_js_value(obj: &wasm_bindgen::JsValue) -> Option<#name> { |
| obj.as_string().and_then(|obj_str| Self::from_str(obj_str.as_str())) |
| } |
| } |
| |
| // It should really be using &str for all of these, but that requires some major changes to cli-support |
| #[automatically_derived] |
| impl wasm_bindgen::describe::WasmDescribe for #name { |
| fn describe() { |
| <wasm_bindgen::JsValue as wasm_bindgen::describe::WasmDescribe>::describe() |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::IntoWasmAbi for #name { |
| type Abi = <wasm_bindgen::JsValue as wasm_bindgen::convert::IntoWasmAbi>::Abi; |
| |
| #[inline] |
| fn into_abi(self) -> Self::Abi { |
| <wasm_bindgen::JsValue as wasm_bindgen::convert::IntoWasmAbi>::into_abi(self.into()) |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::FromWasmAbi for #name { |
| type Abi = <wasm_bindgen::JsValue as wasm_bindgen::convert::FromWasmAbi>::Abi; |
| |
| unsafe fn from_abi(js: Self::Abi) -> Self { |
| let s = <wasm_bindgen::JsValue as wasm_bindgen::convert::FromWasmAbi>::from_abi(js); |
| #name::from_js_value(&s).unwrap_or(#name::__Nonexhaustive) |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionIntoWasmAbi for #name { |
| #[inline] |
| fn none() -> Self::Abi { <::js_sys::Object as wasm_bindgen::convert::OptionIntoWasmAbi>::none() } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionFromWasmAbi for #name { |
| #[inline] |
| fn is_none(abi: &Self::Abi) -> bool { <::js_sys::Object as wasm_bindgen::convert::OptionFromWasmAbi>::is_none(abi) } |
| } |
| |
| #[automatically_derived] |
| impl From<#name> for wasm_bindgen::JsValue { |
| fn from(obj: #name) -> wasm_bindgen::JsValue { |
| wasm_bindgen::JsValue::from(obj.to_str()) |
| } |
| } |
| }).to_tokens(tokens); |
| } |
| } |
| |
| impl TryToTokens for ast::ImportFunction { |
| fn try_to_tokens(&self, tokens: &mut TokenStream) -> Result<(), Diagnostic> { |
| let mut class_ty = None; |
| let mut is_method = false; |
| match self.kind { |
| ast::ImportFunctionKind::Method { |
| ref ty, ref kind, .. |
| } => { |
| if let ast::MethodKind::Operation(ast::Operation { |
| is_static: false, .. |
| }) = kind |
| { |
| is_method = true; |
| } |
| class_ty = Some(ty); |
| } |
| ast::ImportFunctionKind::Normal => {} |
| } |
| let vis = &self.function.rust_vis; |
| let ret = match &self.function.ret { |
| Some(ty) => quote! { -> #ty }, |
| None => quote!(), |
| }; |
| |
| let mut abi_argument_names = Vec::new(); |
| let mut abi_arguments = Vec::new(); |
| let mut arg_conversions = Vec::new(); |
| let mut arguments = Vec::new(); |
| let ret_ident = Ident::new("_ret", Span::call_site()); |
| |
| for (i, arg) in self.function.arguments.iter().enumerate() { |
| let ty = &arg.ty; |
| let name = match &*arg.pat { |
| syn::Pat::Ident(syn::PatIdent { |
| by_ref: None, |
| ident, |
| subpat: None, |
| .. |
| }) => ident.clone(), |
| syn::Pat::Wild(_) => syn::Ident::new(&format!("__genarg_{}", i), Span::call_site()), |
| _ => bail_span!( |
| arg.pat, |
| "unsupported pattern in #[wasm_bindgen] imported function", |
| ), |
| }; |
| |
| abi_argument_names.push(name.clone()); |
| abi_arguments.push(quote! { |
| #name: <#ty as wasm_bindgen::convert::IntoWasmAbi>::Abi |
| }); |
| let var = if i == 0 && is_method { |
| quote! { self } |
| } else { |
| arguments.push(quote! { #name: #ty }); |
| quote! { #name } |
| }; |
| arg_conversions.push(quote! { |
| let #name = <#ty as wasm_bindgen::convert::IntoWasmAbi> |
| ::into_abi(#var); |
| }); |
| } |
| let abi_ret; |
| let mut convert_ret; |
| match &self.js_ret { |
| Some(syn::Type::Reference(_)) => { |
| bail_span!( |
| self.js_ret, |
| "cannot return references in #[wasm_bindgen] imports yet" |
| ); |
| } |
| Some(ref ty) => { |
| if self.function.r#async { |
| abi_ret = |
| quote! { <js_sys::Promise as wasm_bindgen::convert::FromWasmAbi>::Abi }; |
| let future = quote! { |
| wasm_bindgen_futures::JsFuture::from( |
| <js_sys::Promise as wasm_bindgen::convert::FromWasmAbi> |
| ::from_abi(#ret_ident) |
| ).await |
| }; |
| convert_ret = if self.catch { |
| quote! { Ok(#future?) } |
| } else { |
| quote! { #future.expect("unexpected exception") } |
| }; |
| } else { |
| abi_ret = quote! { |
| <#ty as wasm_bindgen::convert::FromWasmAbi>::Abi |
| }; |
| convert_ret = quote! { |
| <#ty as wasm_bindgen::convert::FromWasmAbi> |
| ::from_abi(#ret_ident) |
| }; |
| } |
| } |
| None => { |
| if self.function.r#async { |
| abi_ret = |
| quote! { <js_sys::Promise as wasm_bindgen::convert::FromWasmAbi>::Abi }; |
| let future = quote! { |
| wasm_bindgen_futures::JsFuture::from( |
| <js_sys::Promise as wasm_bindgen::convert::FromWasmAbi> |
| ::from_abi(#ret_ident) |
| ).await |
| }; |
| convert_ret = if self.catch { |
| quote! { #future?; Ok(()) } |
| } else { |
| quote! { #future.expect("uncaught exception"); } |
| }; |
| } else { |
| abi_ret = quote! { () }; |
| convert_ret = quote! { () }; |
| } |
| } |
| } |
| |
| let mut exceptional_ret = quote!(); |
| if self.catch && !self.function.r#async { |
| convert_ret = quote! { Ok(#convert_ret) }; |
| exceptional_ret = quote! { |
| wasm_bindgen::__rt::take_last_exception()?; |
| }; |
| } |
| |
| let rust_name = &self.rust_name; |
| let import_name = &self.shim; |
| let attrs = &self.function.rust_attrs; |
| let arguments = &arguments; |
| let abi_arguments = &abi_arguments[..]; |
| let abi_argument_names = &abi_argument_names[..]; |
| |
| let doc_comment = &self.doc_comment; |
| let me = if is_method { |
| quote! { &self, } |
| } else { |
| quote!() |
| }; |
| |
| // Route any errors pointing to this imported function to the identifier |
| // of the function we're imported from so we at least know what function |
| // is causing issues. |
| // |
| // Note that this is where type errors like "doesn't implement |
| // FromWasmAbi" or "doesn't implement IntoWasmAbi" currently get routed. |
| // I suspect that's because they show up in the signature via trait |
| // projections as types of arguments, and all that needs to typecheck |
| // before the body can be typechecked. Due to rust-lang/rust#60980 (and |
| // probably related issues) we can't really get a precise span. |
| // |
| // Ideally what we want is to point errors for particular types back to |
| // the specific argument/type that generated the error, but it looks |
| // like rustc itself doesn't do great in that regard so let's just do |
| // the best we can in the meantime. |
| let extern_fn = respan( |
| extern_fn( |
| import_name, |
| attrs, |
| abi_arguments, |
| abi_argument_names, |
| abi_ret, |
| ), |
| &self.rust_name, |
| ); |
| |
| let maybe_async = if self.function.r#async { |
| Some(quote! {async}) |
| } else { |
| None |
| }; |
| let invocation = quote! { |
| // This is due to `#[automatically_derived]` attribute cannot be |
| // placed onto bare functions. |
| #[allow(nonstandard_style)] |
| #[allow(clippy::all, clippy::nursery, clippy::pedantic, clippy::restriction)] |
| #(#attrs)* |
| #[doc = #doc_comment] |
| #vis #maybe_async fn #rust_name(#me #(#arguments),*) #ret { |
| #extern_fn |
| |
| unsafe { |
| let #ret_ident = { |
| #(#arg_conversions)* |
| #import_name(#(#abi_argument_names),*) |
| }; |
| #exceptional_ret |
| #convert_ret |
| } |
| } |
| }; |
| |
| if let Some(class) = class_ty { |
| (quote! { |
| #[automatically_derived] |
| impl #class { |
| #invocation |
| } |
| }) |
| .to_tokens(tokens); |
| } else { |
| invocation.to_tokens(tokens); |
| } |
| |
| Ok(()) |
| } |
| } |
| |
| // See comment above in ast::Export for what's going on here. |
| struct DescribeImport<'a> { |
| kind: &'a ast::ImportKind, |
| } |
| |
| impl<'a> ToTokens for DescribeImport<'a> { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| let f = match *self.kind { |
| ast::ImportKind::Function(ref f) => f, |
| ast::ImportKind::Static(_) => return, |
| ast::ImportKind::Type(_) => return, |
| ast::ImportKind::Enum(_) => return, |
| }; |
| let argtys = f.function.arguments.iter().map(|arg| &arg.ty); |
| let nargs = f.function.arguments.len() as u32; |
| let inform_ret = match &f.js_ret { |
| Some(ref t) => quote! { <#t as WasmDescribe>::describe(); }, |
| // async functions always return a JsValue, even if they say to return () |
| None if f.function.r#async => quote! { <JsValue as WasmDescribe>::describe(); }, |
| None => quote! { <() as WasmDescribe>::describe(); }, |
| }; |
| |
| Descriptor { |
| ident: &f.shim, |
| inner: quote! { |
| inform(FUNCTION); |
| inform(0); |
| inform(#nargs); |
| #(<#argtys as WasmDescribe>::describe();)* |
| #inform_ret |
| #inform_ret |
| }, |
| attrs: f.function.rust_attrs.clone(), |
| } |
| .to_tokens(tokens); |
| } |
| } |
| |
| impl ToTokens for ast::Enum { |
| fn to_tokens(&self, into: &mut TokenStream) { |
| let enum_name = &self.rust_name; |
| let hole = &self.hole; |
| let cast_clauses = self.variants.iter().map(|variant| { |
| let variant_name = &variant.name; |
| quote! { |
| if js == #enum_name::#variant_name as u32 { |
| #enum_name::#variant_name |
| } |
| } |
| }); |
| (quote! { |
| #[automatically_derived] |
| impl wasm_bindgen::convert::IntoWasmAbi for #enum_name { |
| type Abi = u32; |
| |
| #[inline] |
| fn into_abi(self) -> u32 { |
| self as u32 |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::FromWasmAbi for #enum_name { |
| type Abi = u32; |
| |
| #[inline] |
| unsafe fn from_abi(js: u32) -> Self { |
| #(#cast_clauses else)* { |
| wasm_bindgen::throw_str("invalid enum value passed") |
| } |
| } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionFromWasmAbi for #enum_name { |
| #[inline] |
| fn is_none(val: &u32) -> bool { *val == #hole } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::convert::OptionIntoWasmAbi for #enum_name { |
| #[inline] |
| fn none() -> Self::Abi { #hole } |
| } |
| |
| #[automatically_derived] |
| impl wasm_bindgen::describe::WasmDescribe for #enum_name { |
| fn describe() { |
| use wasm_bindgen::describe::*; |
| inform(ENUM); |
| inform(#hole); |
| } |
| } |
| }) |
| .to_tokens(into); |
| } |
| } |
| |
| impl ToTokens for ast::ImportStatic { |
| fn to_tokens(&self, into: &mut TokenStream) { |
| let name = &self.rust_name; |
| let ty = &self.ty; |
| let shim_name = &self.shim; |
| let vis = &self.vis; |
| (quote! { |
| #[automatically_derived] |
| #vis static #name: wasm_bindgen::JsStatic<#ty> = { |
| fn init() -> #ty { |
| #[link(wasm_import_module = "__wbindgen_placeholder__")] |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| extern "C" { |
| fn #shim_name() -> <#ty as wasm_bindgen::convert::FromWasmAbi>::Abi; |
| } |
| #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))] |
| unsafe fn #shim_name() -> <#ty as wasm_bindgen::convert::FromWasmAbi>::Abi { |
| panic!("cannot access imported statics on non-wasm targets") |
| } |
| |
| unsafe { |
| <#ty as wasm_bindgen::convert::FromWasmAbi>::from_abi(#shim_name()) |
| } |
| } |
| thread_local!(static _VAL: #ty = init();); |
| wasm_bindgen::JsStatic { |
| __inner: &_VAL, |
| } |
| }; |
| }) |
| .to_tokens(into); |
| |
| Descriptor { |
| ident: &shim_name, |
| inner: quote! { |
| <#ty as WasmDescribe>::describe(); |
| }, |
| attrs: vec![], |
| } |
| .to_tokens(into); |
| } |
| } |
| |
| /// Emits the necessary glue tokens for "descriptor", generating an appropriate |
| /// symbol name as well as attributes around the descriptor function itself. |
| struct Descriptor<'a, T> { |
| ident: &'a Ident, |
| inner: T, |
| attrs: Vec<syn::Attribute>, |
| } |
| |
| impl<'a, T: ToTokens> ToTokens for Descriptor<'a, T> { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| // It's possible for the same descriptor to be emitted in two different |
| // modules (aka a value imported twice in a crate, each in a separate |
| // module). In this case no need to emit duplicate descriptors (which |
| // leads to duplicate symbol errors), instead just emit one. |
| // |
| // It's up to the descriptors themselves to ensure they have unique |
| // names for unique items imported, currently done via `ShortHash` and |
| // hashing appropriate data into the symbol name. |
| static DESCRIPTORS_EMITTED: Lazy<Mutex<HashSet<String>>> = Lazy::new(Default::default); |
| |
| let ident = self.ident; |
| |
| if !DESCRIPTORS_EMITTED |
| .lock() |
| .unwrap() |
| .insert(ident.to_string()) |
| { |
| return; |
| } |
| |
| let name = Ident::new(&format!("__wbindgen_describe_{}", ident), ident.span()); |
| let inner = &self.inner; |
| let attrs = &self.attrs; |
| (quote! { |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| #[automatically_derived] |
| const _: () = { |
| #(#attrs)* |
| #[no_mangle] |
| #[doc(hidden)] |
| pub extern "C" fn #name() { |
| use wasm_bindgen::describe::*; |
| // See definition of `link_mem_intrinsics` for what this is doing |
| wasm_bindgen::__rt::link_mem_intrinsics(); |
| #inner |
| } |
| }; |
| }) |
| .to_tokens(tokens); |
| } |
| } |
| |
| fn extern_fn( |
| import_name: &Ident, |
| attrs: &[syn::Attribute], |
| abi_arguments: &[TokenStream], |
| abi_argument_names: &[Ident], |
| abi_ret: TokenStream, |
| ) -> TokenStream { |
| quote! { |
| #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] |
| #(#attrs)* |
| #[link(wasm_import_module = "__wbindgen_placeholder__")] |
| extern "C" { |
| fn #import_name(#(#abi_arguments),*) -> #abi_ret; |
| } |
| |
| #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))] |
| unsafe fn #import_name(#(#abi_arguments),*) -> #abi_ret { |
| #( |
| drop(#abi_argument_names); |
| )* |
| panic!("cannot call wasm-bindgen imported functions on \ |
| non-wasm targets"); |
| } |
| } |
| } |
| |
| /// Converts `span` into a stream of tokens, and attempts to ensure that `input` |
| /// has all the appropriate span information so errors in it point to `span`. |
| fn respan(input: TokenStream, span: &dyn ToTokens) -> TokenStream { |
| let mut first_span = Span::call_site(); |
| let mut last_span = Span::call_site(); |
| let mut spans = TokenStream::new(); |
| span.to_tokens(&mut spans); |
| |
| for (i, token) in spans.into_iter().enumerate() { |
| if i == 0 { |
| first_span = token.span(); |
| } |
| last_span = token.span(); |
| } |
| |
| let mut new_tokens = Vec::new(); |
| for (i, mut token) in input.into_iter().enumerate() { |
| if i == 0 { |
| token.set_span(first_span); |
| } else { |
| token.set_span(last_span); |
| } |
| new_tokens.push(token); |
| } |
| new_tokens.into_iter().collect() |
| } |
