Split out the AST and codegen into the wasm-bindgen-backend crate

crates/backend/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "wasm-bindgen-backend"
+version = "0.1.0"
+authors = ["Nick Fitzgerald <fitzgen@gmail.com>"]
+
+[dependencies]
+quote = '0.4'
+proc-macro2 = { version = "0.2", features = ["nightly"] }
+wasm-bindgen-shared = { path = "../shared", version = "0.1.0" }
+syn = { version = '0.12', features = ['full'] }

crates/backend/src/ast.rs

@@ -1,6 +1,6 @@
 use literal::{self, Literal};
 use proc_macro2::Span;
-use quote::{Tokens, ToTokens};
+use quote::{ToTokens, Tokens};
 use shared;
 use syn;
 
@@ -39,14 +39,8 @@ pub struct ImportFunction {
 }
 
 pub enum ImportFunctionKind {
-    Method {
+    Method { class: String, ty: syn::Type },
-        class: String,
+    JsConstructor { class: String, ty: syn::Type },
-        ty: syn::Type,
-    },
-    JsConstructor {
-        class: String,
-        ty: syn::Type,
-    },
     Normal,
 }
 
@@ -79,7 +73,7 @@ pub struct Struct {
 
 pub struct Enum {
     pub name: syn::Ident,
-    pub variants: Vec<Variant>
+    pub variants: Vec<Variant>,
 }
 
 pub struct Variant {
@@ -110,20 +104,20 @@ pub enum VectorType {
 }
 
 impl Program {
-    pub fn push_item(&mut self,
+    pub fn push_item(&mut self, item: syn::Item, opts: Option<BindgenAttrs>, tokens: &mut Tokens) {
-                     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()
+                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); }
+                    Some((i, _)) => {
+                        f.attrs.remove(i);
+                    }
                     _ => {}
                 }
                 f.to_tokens(tokens);
@@ -153,8 +147,10 @@ impl Program {
                 e.to_tokens(tokens);
                 self.push_enum(e, opts);
             }
-            _ => panic!("#[wasm_bindgen] can only be applied to a function, \
+            _ => panic!(
-                         struct, enum, impl, or extern block"),
+                "#[wasm_bindgen] can only be applied to a function, \
+                 struct, enum, impl, or extern block"
+            ),
         }
     }
 
@@ -172,12 +168,13 @@ impl Program {
             panic!("generic impls aren't supported");
         }
         let name = match *item.self_ty {
-            syn::Type::Path(syn::TypePath { qself: None, ref path }) => {
+            syn::Type::Path(syn::TypePath {
-                match extract_path_ident(path) {
+                qself: None,
-                    Some(ident) => ident,
+                ref path,
-                    None => panic!("unsupported self type in impl"),
+            }) => 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.into_iter() {
@@ -209,12 +206,14 @@ impl Program {
 
         let opts = BindgenAttrs::find(&mut method.attrs);
 
-        let (function, mutable) = Function::from_decl(method.sig.ident,
+        let (function, mutable) = Function::from_decl(
-                                                      Box::new(method.sig.decl),
+            method.sig.ident,
-                                                      method.attrs,
+            Box::new(method.sig.decl),
-                                                      opts,
+            method.attrs,
-                                                      method.vis,
+            opts,
-                                                      true);
+            method.vis,
+            true,
+        );
         self.exports.push(Export {
             class: Some(class),
             method: mutable.is_some(),
@@ -229,30 +228,40 @@ impl Program {
             _ => panic!("only public enums are allowed"),
         }
 
-        let variants = item.variants.iter().enumerate().map(|(i, v)| {
+        let variants = item.variants
-            match v.fields {
+            .iter()
-                syn::Fields::Unit => (),
+            .enumerate()
-                _ => panic!("Only C-Style enums allowed")
+            .map(|(i, v)| {
-            }
+                match v.fields {
-            let value = match v.discriminant {
+                    syn::Fields::Unit => (),
-                Some((_, syn::Expr::Lit(syn::ExprLit {attrs: _, lit: syn::Lit::Int(ref int_lit)}))) => {
+                    _ => panic!("Only C-Style enums allowed"),
-                    if int_lit.value() > <u32>::max_value() as u64 {
+                }
-                        panic!("Enums can only support numbers that can be represented as u32");
+                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
                     }
-                    int_lit.value() as u32
+                    None => i as u32,
-                },
+                    _ => panic!("Enums may only have number literal values"),
-                None => i as u32,
+                };
-                _ => panic!("Enums may only have number literal values")
-            };
 
-            Variant {
+                Variant {
-                name: v.ident,
+                    name: v.ident,
-                value,
+                    value,
-            }
+                }
-        }).collect();
+            })
+            .collect();
         self.enums.push(Enum {
             name: item.ident,
-            variants
+            variants,
         });
     }
 
@@ -281,20 +290,17 @@ impl Program {
                 _ => panic!("only foreign functions/types allowed for now"),
             };
 
-            self.imports.push(Import { module, js_namespace, kind });
+            self.imports.push(Import {
+                module,
+                js_namespace,
+                kind,
+            });
         }
     }
 
-    pub fn push_foreign_fn(&mut self, f: syn::ForeignItemFn, opts: BindgenAttrs)
+    pub fn push_foreign_fn(&mut self, f: syn::ForeignItemFn, opts: BindgenAttrs) -> ImportKind {
-        -> ImportKind
-    {
         let js_name = opts.js_name().unwrap_or(f.ident);
-        let mut wasm = Function::from_decl(js_name,
+        let mut wasm = Function::from_decl(js_name, f.decl, f.attrs, opts, f.vis, false).0;
-                                           f.decl,
-                                           f.attrs,
-                                           opts,
-                                           f.vis,
-                                           false).0;
         if wasm.opts.catch() {
             // TODO: this assumes a whole bunch:
             //
@@ -308,20 +314,19 @@ impl Program {
         }
 
         let kind = if wasm.opts.method() {
-            let class = wasm.arguments.get(0)
+            let class = wasm.arguments
+                .get(0)
                 .expect("methods must have at least one argument");
             let class = match *class {
-                Type::ByRef(ref t) |
+                Type::ByRef(ref t) | Type::ByValue(ref t) => t,
-                Type::ByValue(ref t) => t,
+                Type::ByMutRef(_) => panic!("first method argument cannot be mutable ref"),
-                Type::ByMutRef(_) => {
+                Type::Vector(..) => panic!("method receivers cannot be vectors"),
-                    panic!("first method argument cannot be mutable ref")
-                }
-                Type::Vector(..) => {
-                    panic!("method receivers cannot be vectors")
-                }
             };
             let class_name = match *class {
-                syn::Type::Path(syn::TypePath { qself: None, ref path }) => path,
+                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)
@@ -337,7 +342,10 @@ impl Program {
                 _ => panic!("constructor returns must be bare types"),
             };
             let class_name = match *class {
-                syn::Type::Path(syn::TypePath { qself: None, ref path }) => path,
+                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)
@@ -367,20 +375,18 @@ impl Program {
         })
     }
 
-    pub fn push_foreign_ty(&mut self, f: syn::ForeignItemType)
+    pub fn push_foreign_ty(&mut self, f: syn::ForeignItemType) -> ImportKind {
-        -> ImportKind
-    {
         ImportKind::Type(ImportType {
             vis: f.vis,
-            name: f.ident
+            name: f.ident,
         })
     }
 
-    pub fn push_foreign_static(&mut self,
+    pub fn push_foreign_static(
-                               f: syn::ForeignItemStatic,
+        &mut self,
-                               opts: BindgenAttrs)
+        f: syn::ForeignItemStatic,
-        -> ImportKind
+        opts: BindgenAttrs,
-    {
+    ) -> ImportKind {
         if f.mutability.is_some() {
             panic!("cannot import mutable globals yet")
         }
@@ -427,20 +433,17 @@ impl Function {
             panic!("can only bindgen safe functions");
         }
 
-        Function::from_decl(input.ident,
+        Function::from_decl(input.ident, input.decl, input.attrs, opts, input.vis, false).0
-                            input.decl,
-                            input.attrs,
-                            opts,
-                            input.vis,
-                            false).0
     }
 
-    pub fn from_decl(name: syn::Ident,
+    pub fn from_decl(
-                     decl: Box<syn::FnDecl>,
+        name: syn::Ident,
-                     attrs: Vec<syn::Attribute>,
+        decl: Box<syn::FnDecl>,
-                     opts: BindgenAttrs,
+        attrs: Vec<syn::Attribute>,
-                     vis: syn::Visibility,
+        opts: BindgenAttrs,
-                     allow_self: bool) -> (Function, Option<bool>) {
+        vis: syn::Visibility,
+        allow_self: bool,
+    ) -> (Function, Option<bool>) {
         if decl.variadic.is_some() {
             panic!("can't bindgen variadic functions")
         }
@@ -449,20 +452,19 @@ impl Function {
         }
 
         let mut mutable = None;
-        let arguments = decl.inputs.iter()
+        let arguments = decl.inputs
-            .filter_map(|arg| {
+            .iter()
-                match *arg {
+            .filter_map(|arg| match *arg {
-                    syn::FnArg::Captured(ref c) => Some(c),
+                syn::FnArg::Captured(ref c) => Some(c),
-                    syn::FnArg::SelfValue(_) => {
+                syn::FnArg::SelfValue(_) => {
-                        panic!("by-value `self` not yet supported");
+                    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"),
                 }
+                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| Type::from(&arg.ty))
             .collect::<Vec<_>>();
@@ -472,24 +474,27 @@ impl Function {
             syn::ReturnType::Type(_, ref t) => Some(Type::from(t)),
         };
 
-        (Function {
+        (
-            name,
+            Function {
-            arguments,
+                name,
-            ret,
+                arguments,
-            opts,
+                ret,
-            rust_vis: vis,
+                opts,
-            rust_decl: decl,
+                rust_vis: vis,
-            rust_attrs: attrs,
+                rust_decl: decl,
-        }, mutable)
+                rust_attrs: attrs,
+            },
+            mutable,
+        )
     }
 }
 
 pub fn extract_path_ident(path: &syn::Path) -> Option<syn::Ident> {
     if path.leading_colon.is_some() {
-        return None
+        return None;
     }
     if path.segments.len() != 1 {
-        return None
+        return None;
     }
     match path.segments.first().unwrap().value().arguments {
         syn::PathArguments::None => {}
@@ -503,7 +508,10 @@ impl Type {
         match *ty {
             syn::Type::Reference(ref r) => {
                 match *r.elem {
-                    syn::Type::Path(syn::TypePath { qself: None, ref path }) => {
+                    syn::Type::Path(syn::TypePath {
+                        qself: None,
+                        ref path,
+                    }) => {
                         let ident = extract_path_ident(path);
                         match ident.as_ref().map(|s| s.as_ref()) {
                             Some("str") => return Type::Vector(VectorType::String, false),
@@ -512,7 +520,7 @@ impl Type {
                     }
                     syn::Type::Slice(ref slice) => {
                         if let Some(ty) = VectorType::from(&slice.elem) {
-                            return Type::Vector(ty, false)
+                            return Type::Vector(ty, false);
                         }
                     }
                     _ => {}
@@ -521,26 +529,26 @@ impl Type {
                     Type::ByMutRef((*r.elem).clone())
                 } else {
                     Type::ByRef((*r.elem).clone())
-                }
+                };
             }
-            syn::Type::Path(syn::TypePath { qself: None, ref path })
+            syn::Type::Path(syn::TypePath {
-                if path.leading_colon.is_none() && path.segments.len() == 1 =>
+                qself: None,
+                ref path,
+            }) if path.leading_colon.is_none() && path.segments.len() == 1 =>
             {
                 let seg = path.segments.first().unwrap().into_value();
                 match seg.arguments {
-                    syn::PathArguments::None => {
+                    syn::PathArguments::None => match seg.ident.as_ref() {
-                        match seg.ident.as_ref() {
+                        "String" => return Type::Vector(VectorType::String, true),
-                            "String" => return Type::Vector(VectorType::String, true),
+                        _ => {}
-                            _ => {}
+                    },
-                        }
-                    }
                     syn::PathArguments::AngleBracketed(ref t)
                         if seg.ident == "Vec" && t.args.len() == 1 =>
                     {
                         match **t.args.first().unwrap().value() {
                             syn::GenericArgument::Type(ref t) => {
                                 if let Some(ty) = VectorType::from(t) {
-                                    return Type::Vector(ty, true)
+                                    return Type::Vector(ty, true);
                                 }
                             }
                             _ => {}
@@ -571,14 +579,9 @@ impl Export {
     pub fn export_name(&self) -> syn::LitStr {
         let name = match self.class {
             Some(class) => {
-                shared::struct_function_export_name(
+                shared::struct_function_export_name(class.as_ref(), self.function.name.as_ref())
-                    class.as_ref(),
-                    self.function.name.as_ref(),
-                )
-            }
-            None => {
-                shared::free_function_export_name(self.function.name.as_ref())
             }
+            None => shared::free_function_export_name(self.function.name.as_ref()),
         };
         syn::LitStr::new(&name, Span::def_site())
     }
@@ -609,7 +612,8 @@ pub struct BindgenAttrs {
 
 impl BindgenAttrs {
     pub fn find(attrs: &mut Vec<syn::Attribute>) -> BindgenAttrs {
-        let pos = attrs.iter()
+        let pos = attrs
+            .iter()
             .enumerate()
             .find(|&(_, ref m)| m.path.segments[0].ident == "wasm_bindgen")
             .map(|a| a.0);
@@ -617,101 +621,83 @@ impl BindgenAttrs {
             Some(i) => i,
             None => return BindgenAttrs::default(),
         };
-        syn::parse(attrs.remove(pos).tts.into())
+        syn::parse(attrs.remove(pos).tts.into()).expect("malformed #[wasm_bindgen] attribute")
-            .expect("malformed #[wasm_bindgen] attribute")
     }
 
     fn module(&self) -> Option<&str> {
-        self.attrs.iter()
+        self.attrs
-            .filter_map(|a| {
+            .iter()
-                match *a {
+            .filter_map(|a| match *a {
-                    BindgenAttr::Module(ref s) => Some(&s[..]),
+                BindgenAttr::Module(ref s) => Some(&s[..]),
-                    _ => None,
+                _ => None,
-                }
             })
             .next()
     }
 
     pub fn catch(&self) -> bool {
-        self.attrs.iter()
+        self.attrs.iter().any(|a| match *a {
-            .any(|a| {
+            BindgenAttr::Catch => true,
-                match *a {
+            _ => false,
-                    BindgenAttr::Catch => true,
+        })
-                    _ => false,
-                }
-            })
     }
 
     fn constructor(&self) -> bool {
-        self.attrs.iter()
+        self.attrs.iter().any(|a| match *a {
-            .any(|a| {
+            BindgenAttr::Constructor => true,
-                match *a {
+            _ => false,
-                    BindgenAttr::Constructor => true,
+        })
-                    _ => false,
-                }
-            })
     }
 
     fn method(&self) -> bool {
-        self.attrs.iter()
+        self.attrs.iter().any(|a| match *a {
-            .any(|a| {
+            BindgenAttr::Method => true,
-                match *a {
+            _ => false,
-                    BindgenAttr::Method => true,
+        })
-                    _ => false,
-                }
-            })
     }
 
     fn js_namespace(&self) -> Option<syn::Ident> {
-        self.attrs.iter()
+        self.attrs
-            .filter_map(|a| {
+            .iter()
-                match *a {
+            .filter_map(|a| match *a {
-                    BindgenAttr::JsNamespace(s) => Some(s),
+                BindgenAttr::JsNamespace(s) => Some(s),
-                    _ => None,
+                _ => None,
-                }
             })
             .next()
     }
 
     pub fn getter(&self) -> Option<Option<syn::Ident>> {
-        self.attrs.iter()
+        self.attrs
-            .filter_map(|a| {
+            .iter()
-                match *a {
+            .filter_map(|a| match *a {
-                    BindgenAttr::Getter(s) => Some(s),
+                BindgenAttr::Getter(s) => Some(s),
-                    _ => None,
+                _ => None,
-                }
             })
             .next()
     }
 
     pub fn setter(&self) -> Option<Option<syn::Ident>> {
-        self.attrs.iter()
+        self.attrs
-            .filter_map(|a| {
+            .iter()
-                match *a {
+            .filter_map(|a| match *a {
-                    BindgenAttr::Setter(s) => Some(s),
+                BindgenAttr::Setter(s) => Some(s),
-                    _ => None,
+                _ => None,
-                }
             })
             .next()
     }
 
     pub fn structural(&self) -> bool {
-        self.attrs.iter()
+        self.attrs.iter().any(|a| match *a {
-            .any(|a| {
+            BindgenAttr::Structural => true,
-                match *a {
+            _ => false,
-                    BindgenAttr::Structural => true,
+        })
-                    _ => false,
-                }
-            })
     }
 
     pub fn js_name(&self) -> Option<syn::Ident> {
-        self.attrs.iter()
+        self.attrs
-            .filter_map(|a| {
+            .iter()
-                match *a {
+            .filter_map(|a| match *a {
-                    BindgenAttr::JsName(s) => Some(s),
+                BindgenAttr::JsName(s) => Some(s),
-                    _ => None,
+                _ => None,
-                }
             })
             .next()
     }
@@ -800,14 +786,17 @@ impl syn::synom::Synom for BindgenAttr {
 fn extract_first_ty_param(ty: Option<&Type>) -> Option<Option<Type>> {
     let ty = match ty {
         Some(t) => t,
-        None => return Some(None)
+        None => return Some(None),
     };
     let ty = match *ty {
         Type::ByValue(ref t) => t,
         _ => return None,
     };
     let path = match *ty {
-        syn::Type::Path(syn::TypePath { qself: None, ref path }) => path,
+        syn::Type::Path(syn::TypePath {
+            qself: None,
+            ref path,
+        }) => path,
         _ => return None,
     };
     let seg = path.segments.last()?.into_value();
@@ -826,12 +815,10 @@ fn extract_first_ty_param(ty: Option<&Type>) -> Option<Option<Type>> {
     Some(Some(Type::from(ty)))
 }
 
-fn term<'a>(cursor: syn::buffer::Cursor<'a>, name: &str)
+fn term<'a>(cursor: syn::buffer::Cursor<'a>, name: &str) -> syn::synom::PResult<'a, ()> {
-    -> syn::synom::PResult<'a, ()>
-{
     if let Some((_span, term, next)) = cursor.term() {
         if term.as_str() == name {
-            return Ok(((), next))
+            return Ok(((), next));
         }
     }
     syn::parse_error()
@@ -847,7 +834,10 @@ fn ungroup(input: &syn::Type) -> &syn::Type {
 impl VectorType {
     fn from(ty: &syn::Type) -> Option<VectorType> {
         let path = match *ungroup(ty) {
-            syn::Type::Path(syn::TypePath { qself: None, ref path }) => path,
+            syn::Type::Path(syn::TypePath {
+                qself: None,
+                ref path,
+            }) => path,
             _ => return None,
         };
         match extract_path_ident(path)?.as_ref() {

crates/backend/src/codegen.rs

@@ -0,0 +1,621 @@
+use ast;
+use quote::{ToTokens, Tokens};
+use proc_macro2::Span;
+use shared;
+use std::borrow::Cow;
+use std::collections::HashSet;
+use std::env;
+use std::sync::atomic::{ATOMIC_USIZE_INIT, AtomicUsize, Ordering};
+use syn;
+
+fn to_ident_name(s: &str) -> Cow<str> {
+    if s.chars().all(|c| match c {
+        'a'...'z' | 'A'...'Z' | '0'...'9' | '_' => true,
+        _ => false,
+    }) {
+        return Cow::from(s);
+    }
+
+    Cow::from(
+        s.chars()
+            .map(|c| match c {
+                'a'...'z' | 'A'...'Z' | '0'...'9' | '_' => c,
+                _ => '_',
+            })
+            .collect::<String>(),
+    )
+}
+
+impl ToTokens for ast::Program {
+    // Generate wrappers for all the items that we've found
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        for export in self.exports.iter() {
+            export.to_tokens(tokens);
+        }
+        for s in self.structs.iter() {
+            s.to_tokens(tokens);
+        }
+        let mut types = HashSet::new();
+        for i in self.imports.iter() {
+            if let ast::ImportKind::Type(ref t) = i.kind {
+                types.insert(t.name);
+            }
+        }
+        for i in self.imports.iter() {
+            match i.js_namespace {
+                Some(ns) if types.contains(&ns) => {
+                    let kind = &i.kind;
+                    (quote! { impl #ns { #kind } }).to_tokens(tokens);
+                }
+                _ => i.kind.to_tokens(tokens),
+            }
+        }
+        for e in self.enums.iter() {
+            e.to_tokens(tokens);
+        }
+
+        // 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.
+
+        static CNT: AtomicUsize = ATOMIC_USIZE_INIT;
+
+        let crate_name = env::var("CARGO_PKG_NAME").expect("should have CARGO_PKG_NAME env var");
+        let crate_vers =
+            env::var("CARGO_PKG_VERSION").expect("should have CARGO_PKG_VERSION env var");
+
+        let generated_static_name = format!(
+            "__WASM_BINDGEN_GENERATED_{}_{}_{}",
+            to_ident_name(&crate_name),
+            to_ident_name(&crate_vers),
+            CNT.fetch_add(1, Ordering::SeqCst)
+        );
+        let generated_static_name = syn::Ident::from(generated_static_name);
+
+        let mut generated_static_value = Tokens::new();
+        let generated_static_length = self.literal(&mut generated_static_value);
+
+        (my_quote! {
+            #[allow(non_upper_case_globals)]
+            #[wasm_custom_section = "__wasm_bindgen_unstable"]
+            const #generated_static_name: [u8; #generated_static_length] =
+                [#generated_static_value];
+        }).to_tokens(tokens);
+    }
+}
+
+impl ToTokens for ast::Struct {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        let name = &self.name;
+        let free_fn = syn::Ident::from(shared::free_function(self.name.as_ref()));
+        let c = shared::name_to_descriptor(name.as_ref()) as u32;
+        (my_quote! {
+            impl ::wasm_bindgen::convert::WasmBoundary for #name {
+                type Js = u32;
+                const DESCRIPTOR: u32 = #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: u32) {
+                <#name as ::wasm_bindgen::convert::WasmBoundary>::from_js(ptr);
+            }
+        }).to_tokens(tokens);
+    }
+}
+
+impl ToTokens for ast::Export {
+    fn to_tokens(self: &ast::Export, into: &mut Tokens) {
+        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 = syn::Ident::from("_ret");
+
+        let mut offset = 0;
+        if self.method {
+            let class = self.class.unwrap();
+            args.push(my_quote! { me: *mut ::wasm_bindgen::__rt::WasmRefCell<#class> });
+            arg_conversions.push(my_quote! {
+                ::wasm_bindgen::__rt::assert_not_null(me);
+                let me = unsafe { &*me };
+            });
+            offset = 1;
+        }
+
+        for (i, ty) in self.function.arguments.iter().enumerate() {
+            let i = i + offset;
+            let ident = syn::Ident::from(format!("arg{}", i));
+            match *ty {
+                ast::Type::Vector(ref ty, owned) => {
+                    let ptr = syn::Ident::from(format!("arg{}_ptr", i));
+                    let len = syn::Ident::from(format!("arg{}_len", i));
+                    let abi_ty = ty.abi_element();
+                    args.push(my_quote! { #ptr: *mut #abi_ty });
+                    args.push(my_quote! { #len: usize });
+                    if owned {
+                        arg_conversions.push(my_quote! {
+                            let #ident = unsafe {
+                                ::std::vec::Vec::from_raw_parts(#ptr, #len, #len)
+                            };
+                        });
+                    } else {
+                        arg_conversions.push(my_quote! {
+                            let #ident = unsafe {
+                                ::std::slice::from_raw_parts(#ptr as *const #abi_ty, #len)
+                            };
+                        });
+                    }
+                    if let ast::VectorType::String = *ty {
+                        if owned {
+                            arg_conversions.push(my_quote! {
+                                let #ident = unsafe {
+                                    ::std::string::String::from_utf8_unchecked(#ident)
+                                };
+                            });
+                        } else {
+                            arg_conversions.push(my_quote! {
+                                let #ident = unsafe {
+                                    ::std::str::from_utf8_unchecked(#ident)
+                                };
+                            });
+                        }
+                    }
+                }
+                ast::Type::ByValue(ref t) => {
+                    args.push(my_quote! {
+                        #ident: <#t as ::wasm_bindgen::convert::WasmBoundary >::Js
+                    });
+                    arg_conversions.push(my_quote! {
+                        let #ident = unsafe {
+                            <#t as ::wasm_bindgen::convert::WasmBoundary>
+                                ::from_js(#ident)
+                        };
+                    });
+                }
+                ast::Type::ByRef(ref ty) => {
+                    args.push(my_quote! {
+                        #ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
+                    });
+                    arg_conversions.push(my_quote! {
+                        let #ident = unsafe {
+                            <#ty as ::wasm_bindgen::convert::FromRefWasmBoundary>
+                                ::from_js_ref(#ident)
+                        };
+                        let #ident = &*#ident;
+                    });
+                }
+                ast::Type::ByMutRef(ref ty) => {
+                    args.push(my_quote! {
+                        #ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
+                    });
+                    arg_conversions.push(my_quote! {
+                        let mut #ident = unsafe {
+                            <#ty as ::wasm_bindgen::convert::FromRefMutWasmBoundary>
+                                ::from_js_ref_mut(#ident)
+                        };
+                        let #ident = &mut *#ident;
+                    });
+                }
+            }
+            converted_arguments.push(my_quote! { #ident });
+        }
+        let ret_ty;
+        let convert_ret;
+        match self.function.ret {
+            Some(ast::Type::Vector(ref ty, true)) => {
+                ret_ty = my_quote! { -> *mut #ty };
+                convert_ret = my_quote! { Box::into_raw(Box::new(#ret)) };
+            }
+            Some(ast::Type::ByValue(ref t)) => {
+                ret_ty = my_quote! {
+                    -> <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
+                };
+                convert_ret = my_quote! {
+                    <#t as ::wasm_bindgen::convert::WasmBoundary>::into_js(#ret)
+                };
+            }
+            Some(ast::Type::Vector(_, false))
+            | Some(ast::Type::ByMutRef(_))
+            | Some(ast::Type::ByRef(_)) => {
+                panic!("can't return a borrowed ref");
+            }
+            None => {
+                ret_ty = my_quote!{};
+                convert_ret = my_quote!{};
+            }
+        }
+
+        let name = self.function.name;
+        let receiver = match self.class {
+            Some(_) if self.method => {
+                if self.mutable {
+                    my_quote! { me.borrow_mut().#name }
+                } else {
+                    my_quote! { me.borrow().#name }
+                }
+            }
+            Some(class) => my_quote! { #class::#name },
+            None => my_quote!{ #name },
+        };
+
+        let tokens = my_quote! {
+            #[export_name = #export_name]
+            #[allow(non_snake_case)]
+            pub extern fn #generated_name(#(#args),*) #ret_ty {
+                ::wasm_bindgen::__rt::link_this_library();
+                #(#arg_conversions)*
+                let #ret = #receiver(#(#converted_arguments),*);
+                #convert_ret
+            }
+        };
+        tokens.to_tokens(into);
+    }
+}
+
+impl ToTokens for ast::ImportType {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        let vis = &self.vis;
+        let name = &self.name;
+        (my_quote! {
+            #[allow(bad_style)]
+            #vis struct #name {
+                obj: ::wasm_bindgen::JsValue,
+            }
+
+            impl ::wasm_bindgen::convert::WasmBoundary for #name {
+                type Js = <::wasm_bindgen::JsValue as
+                    ::wasm_bindgen::convert::WasmBoundary>::Js;
+                const DESCRIPTOR: u32 = <::wasm_bindgen::JsValue as
+                    ::wasm_bindgen::convert::WasmBoundary>::DESCRIPTOR;
+
+                fn into_js(self) -> Self::Js {
+                    self.obj.into_js()
+                }
+
+                unsafe fn from_js(js: Self::Js) -> Self {
+                    #name { obj: ::wasm_bindgen::JsValue::from_js(js) }
+                }
+            }
+
+            impl ::wasm_bindgen::convert::ToRefWasmBoundary for #name {
+                fn to_js_ref(&self) -> u32 {
+                    self.obj.to_js_ref()
+                }
+            }
+
+            impl ::wasm_bindgen::convert::FromRefWasmBoundary for #name {
+                type RefAnchor = ::std::mem::ManuallyDrop<#name>;
+                unsafe fn from_js_ref(js: Self::Js) -> Self::RefAnchor {
+                    let obj = <::wasm_bindgen::JsValue as ::wasm_bindgen::convert::WasmBoundary>
+                        ::from_js(js);
+                    ::std::mem::ManuallyDrop::new(#name { obj })
+                }
+            }
+
+
+            impl From<::wasm_bindgen::JsValue> for #name {
+                fn from(obj: ::wasm_bindgen::JsValue) -> #name {
+                    #name { obj }
+                }
+            }
+
+            impl From<#name> for ::wasm_bindgen::JsValue {
+                fn from(obj: #name) -> ::wasm_bindgen::JsValue {
+                    obj.obj
+                }
+            }
+        }).to_tokens(tokens);
+    }
+}
+
+impl ToTokens for ast::ImportKind {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        match *self {
+            ast::ImportKind::Function(ref f) => f.to_tokens(tokens),
+            ast::ImportKind::Static(ref s) => s.to_tokens(tokens),
+            ast::ImportKind::Type(ref t) => t.to_tokens(tokens),
+        }
+    }
+}
+
+impl ToTokens for ast::ImportFunction {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        let mut class_ty = None;
+        let mut is_method = false;
+        match self.kind {
+            ast::ImportFunctionKind::Method { ref ty, .. } => {
+                is_method = true;
+                class_ty = Some(ty);
+            }
+            ast::ImportFunctionKind::JsConstructor { ref ty, .. } => {
+                class_ty = Some(ty);
+            }
+            ast::ImportFunctionKind::Normal => {}
+        }
+        let vis = &self.function.rust_vis;
+        let ret = &self.function.rust_decl.output;
+        let fn_token = &self.function.rust_decl.fn_token;
+
+        let mut abi_argument_names = Vec::new();
+        let mut abi_arguments = Vec::new();
+        let mut arg_conversions = Vec::new();
+        let ret_ident = syn::Ident::from("_ret");
+
+        let names = self.function
+            .rust_decl
+            .inputs
+            .iter()
+            .map(|arg| match *arg {
+                syn::FnArg::Captured(ref c) => c,
+                _ => panic!("arguments cannot be `self` or ignored"),
+            })
+            .map(|arg| match arg.pat {
+                syn::Pat::Ident(syn::PatIdent {
+                    by_ref: None,
+                    ident,
+                    subpat: None,
+                    ..
+                }) => ident,
+                _ => panic!("unsupported pattern in foreign function"),
+            });
+
+        for (i, (ty, name)) in self.function.arguments.iter().zip(names).enumerate() {
+            match *ty {
+                ast::Type::Vector(ref ty, owned) => {
+                    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);
+                    let abi_ty = ty.abi_element();
+                    abi_arguments.push(my_quote! { #ptr: *const #abi_ty });
+                    abi_arguments.push(my_quote! { #len: usize });
+                    arg_conversions.push(my_quote! {
+                        let #ptr = #name.as_ptr();
+                        let #len = #name.len();
+                    });
+                    if owned {
+                        arg_conversions.push(my_quote! { ::std::mem::forget(#name); });
+                    }
+                }
+                ast::Type::ByValue(ref t) => {
+                    abi_argument_names.push(name);
+                    abi_arguments.push(my_quote! {
+                        #name: <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
+                    });
+                    if i == 0 && is_method {
+                        arg_conversions.push(my_quote! {
+                            let #name = <#t as ::wasm_bindgen::convert::WasmBoundary>
+                                ::into_js(self);
+                        });
+                    } else {
+                        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 });
+                    if i == 0 && is_method {
+                        arg_conversions.push(my_quote! {
+                            let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
+                                ::to_js_ref(self);
+                        });
+                    } else {
+                        arg_conversions.push(my_quote! {
+                            let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
+                                ::to_js_ref(#name);
+                        });
+                    }
+                }
+            }
+        }
+        let abi_ret;
+        let mut convert_ret;
+        match self.function.ret {
+            Some(ast::Type::ByValue(ref t)) => {
+                abi_ret = my_quote! {
+                    <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
+                };
+                convert_ret = my_quote! {
+                    <#t as ::wasm_bindgen::convert::WasmBoundary>::from_js(#ret_ident)
+                };
+            }
+
+            Some(ast::Type::Vector(ref ty, true)) => {
+                let name = syn::Ident::from("__ret_len");
+                let name_ptr = syn::Ident::from("__ret_len_ptr");
+                abi_argument_names.push(name_ptr);
+                abi_arguments.push(my_quote! { #name_ptr: *mut usize });
+                arg_conversions.push(my_quote! {
+                    let mut #name = 0;
+                    let mut #name_ptr = &mut #name as *mut usize;
+                });
+                let abi_ty = ty.abi_element();
+                abi_ret = my_quote! { *mut #abi_ty };
+                if let ast::VectorType::String = *ty {
+                    convert_ret = my_quote! {
+                        String::from_utf8_unchecked(
+                            Vec::from_raw_parts(#ret_ident, #name, #name)
+                        )
+                    };
+                } else {
+                    convert_ret = my_quote! {
+                        Vec::from_raw_parts(#ret_ident, #name, #name)
+                    };
+                }
+            }
+            Some(ast::Type::ByRef(_))
+            | Some(ast::Type::Vector(_, false))
+            | Some(ast::Type::ByMutRef(_)) => panic!("can't return a borrowed ref"),
+            None => {
+                abi_ret = my_quote! { () };
+                convert_ret = my_quote! { () };
+            }
+        }
+
+        let mut exceptional_ret = my_quote!{};
+        if self.function.opts.catch() {
+            let exn_data = syn::Ident::from("exn_data");
+            let exn_data_ptr = syn::Ident::from("exn_data_ptr");
+            abi_argument_names.push(exn_data_ptr);
+            abi_arguments.push(my_quote! { #exn_data_ptr: *mut u32 });
+            arg_conversions.push(my_quote! {
+                let mut #exn_data = [0; 2];
+                let #exn_data_ptr = #exn_data.as_mut_ptr();
+            });
+            convert_ret = my_quote! { Ok(#convert_ret) };
+            exceptional_ret = my_quote! {
+                if #exn_data[0] == 1 {
+                    return Err(<::wasm_bindgen::JsValue as
+                        ::wasm_bindgen::convert::WasmBoundary>::from_js(#exn_data[1]))
+                }
+            };
+        }
+
+        let rust_name = self.rust_name;
+        let import_name = self.shim;
+        let attrs = &self.function.rust_attrs;
+
+        let arguments = self.function
+            .rust_decl
+            .inputs
+            .iter()
+            .skip(if is_method { 1 } else { 0 })
+            .collect::<Vec<_>>();
+
+        let me = if is_method {
+            my_quote! { &self, }
+        } else {
+            quote!()
+        };
+
+        let invocation = my_quote! {
+            #(#attrs)*
+            #[allow(bad_style)]
+            #vis extern #fn_token #rust_name(#me #(#arguments),*) #ret {
+                ::wasm_bindgen::__rt::link_this_library();
+                #[wasm_import_module = "__wbindgen_placeholder__"]
+                extern {
+                    fn #import_name(#(#abi_arguments),*) -> #abi_ret;
+                }
+                unsafe {
+                    #(#arg_conversions)*
+                    let #ret_ident = #import_name(#(#abi_argument_names),*);
+                    #exceptional_ret
+                    #convert_ret
+                }
+            }
+        };
+
+        if let Some(class) = class_ty {
+            (quote! {
+                impl #class {
+                    #invocation
+                }
+            }).to_tokens(tokens);
+        } else {
+            invocation.to_tokens(tokens);
+        }
+    }
+}
+
+impl ToTokens for ast::Enum {
+    fn to_tokens(&self, into: &mut Tokens) {
+        let enum_name = &self.name;
+        let c = shared::TYPE_ENUM as u32;
+        let incoming_u32 = quote! { n };
+        let enum_name_as_string = enum_name.to_string();
+        let cast_clauses = self.variants.iter().map(|variant| {
+            let variant_name = &variant.name;
+            quote! {
+                if #incoming_u32 == #enum_name::#variant_name as u32 {
+                    #enum_name::#variant_name
+                }
+            }
+        });
+        (my_quote! {
+            impl #enum_name {
+                fn from_u32(#incoming_u32: u32) -> #enum_name {
+                    #(#cast_clauses else)* {
+                        wasm_bindgen::throw(&format!("Could not cast {} as {}", #incoming_u32, #enum_name_as_string));
+                    }
+                }
+            }
+
+            impl ::wasm_bindgen::convert::WasmBoundary for #enum_name {
+                type Js = u32;
+                const DESCRIPTOR: u32 = #c;
+
+                fn into_js(self) -> u32 {
+                    self as u32
+                }
+
+                unsafe fn from_js(js: u32) -> Self {
+                    #enum_name::from_u32(js)
+                }
+            }
+        }).to_tokens(into);
+    }
+}
+
+impl ToTokens for ast::ImportStatic {
+    fn to_tokens(&self, into: &mut Tokens) {
+        let name = self.rust_name;
+        let ty = &self.ty;
+        let shim_name = self.shim;
+        let vis = &self.vis;
+        (my_quote! {
+            #[allow(bad_style)]
+            #vis static #name: ::wasm_bindgen::JsStatic<#ty> = {
+                fn init() -> #ty {
+                    #[wasm_import_module = "__wbindgen_placeholder__"]
+                    extern {
+                        fn #shim_name() -> u32;
+                    }
+                    unsafe {
+                        ::wasm_bindgen::convert::WasmBoundary::from_js(#shim_name())
+                    }
+                }
+                ::wasm_bindgen::JsStatic {
+                    __inner: ::std::cell::UnsafeCell::new(None),
+                    __init: init,
+                }
+            };
+        }).to_tokens(into);
+    }
+}

crates/backend/src/lib.rs

@@ -0,0 +1,25 @@
+#![recursion_limit = "128"]
+
+extern crate proc_macro2;
+#[macro_use]
+extern crate quote;
+#[macro_use]
+extern crate syn;
+
+extern crate wasm_bindgen_shared as shared;
+
+macro_rules! my_quote {
+    ($($t:tt)*) => (quote_spanned!(Span::call_site() => $($t)*))
+}
+
+pub mod ast;
+mod codegen;
+mod literal;
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}

crates/backend/src/literal.rs

@@ -11,10 +11,7 @@ pub struct LiteralBuilder<'a> {
 
 impl<'a> LiteralBuilder<'a> {
     pub fn new(dst: &'a mut Tokens) -> LiteralBuilder<'a> {
-        LiteralBuilder {
+        LiteralBuilder { dst, cnt: 0 }
-            dst,
-            cnt: 0,
-        }
     }
 
     pub fn finish(self) -> usize {
@@ -95,8 +92,9 @@ impl<'a> LiteralBuilder<'a> {
     }
 
     fn list<T, F>(&mut self, list: T, mut cb: F)
-        where F: FnMut(T::Item, &mut Self),
+    where
-              T: IntoIterator,
+        F: FnMut(T::Item, &mut Self),
+        T: IntoIterator,
     {
         self.append("[");
         for (i, element) in list.into_iter().enumerate() {
@@ -316,8 +314,6 @@ impl Literal for ast::ImportStatic {
 
 impl Literal for ast::ImportType {
     fn literal(&self, a: &mut LiteralBuilder) {
-        a.fields(&[
+        a.fields(&[("kind", &|a| a.str("type"))])
-            ("kind", &|a| a.str("type")),
-        ])
     }
 }

crates/macro/Cargo.toml

@@ -19,3 +19,4 @@ quote = '0.4'
 proc-macro2 = { version = "0.2", features = ["nightly"] }
 serde_json = "1"
 wasm-bindgen-shared = { path = "../shared", version = "0.1.0" }
+wasm-bindgen-backend = { path = "../backend", version = "0.1.0" }

crates/macro/src/lib.rs

@@ -1,40 +1,24 @@
-#![recursion_limit = "128"]
 #![feature(proc_macro)]
 
-#[macro_use]
 extern crate syn;
-#[macro_use]
 extern crate quote;
 extern crate proc_macro;
 extern crate proc_macro2;
 extern crate serde_json;
+extern crate wasm_bindgen_backend as backend;
 extern crate wasm_bindgen_shared as shared;
 
-use std::borrow::Cow;
-use std::env;
-use std::sync::atomic::*;
-use std::collections::HashSet;
-
 use proc_macro::TokenStream;
-use proc_macro2::Span;
+use quote::{ToTokens, Tokens};
-use quote::{Tokens, ToTokens};
-
-macro_rules! my_quote {
-    ($($t:tt)*) => (quote_spanned!(Span::call_site() => $($t)*))
-}
-
-mod ast;
-mod literal;
 
 #[proc_macro_attribute]
 pub fn wasm_bindgen(attr: TokenStream, input: TokenStream) -> TokenStream {
-    let item = syn::parse::<syn::Item>(input.clone())
+    let item = syn::parse::<syn::Item>(input.clone()).expect("expected a valid Rust item");
-        .expect("expected a valid Rust item");
+    let opts = syn::parse::<backend::ast::BindgenAttrs>(attr)
-    let opts = syn::parse::<ast::BindgenAttrs>(attr)
         .expect("invalid arguments to #[wasm_bindgen]");
 
     let mut ret = Tokens::new();
-    let mut program = ast::Program::default();
+    let mut program = backend::ast::Program::default();
     program.push_item(item, Some(opts), &mut ret);
     program.to_tokens(&mut ret);
 
@@ -42,616 +26,3 @@ pub fn wasm_bindgen(attr: TokenStream, input: TokenStream) -> TokenStream {
 
     ret.into()
 }
-
-fn to_ident_name(s: &str) -> Cow<str> {
-    if s.chars().all(|c| match c {
-        'a'...'z' | 'A'...'Z' | '0'...'9' | '_' => true,
-        _ => false,
-    }) {
-        return Cow::from(s);
-    }
-
-    Cow::from(
-        s.chars()
-            .map(|c| match c {
-                'a'...'z' | 'A'...'Z' | '0'...'9' | '_' => c,
-                _ => '_',
-            })
-            .collect::<String>(),
-    )
-}
-
-impl ToTokens for ast::Program {
-    // Generate wrappers for all the items that we've found
-    fn to_tokens(&self, tokens: &mut Tokens) {
-        for export in self.exports.iter() {
-            export.to_tokens(tokens);
-        }
-        for s in self.structs.iter() {
-            s.to_tokens(tokens);
-        }
-        let mut types = HashSet::new();
-        for i in self.imports.iter() {
-            if let ast::ImportKind::Type(ref t) = i.kind {
-                types.insert(t.name);
-            }
-        }
-        for i in self.imports.iter() {
-            match i.js_namespace {
-                Some(ns) if types.contains(&ns) => {
-                    let kind = &i.kind;
-                    (quote! { impl #ns { #kind } }).to_tokens(tokens);
-                }
-                _ => i.kind.to_tokens(tokens),
-            }
-        }
-        for e in self.enums.iter() {
-            e.to_tokens(tokens);
-        }
-
-        // 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.
-
-        static CNT: AtomicUsize = ATOMIC_USIZE_INIT;
-
-        let crate_name = env::var("CARGO_PKG_NAME").expect("should have CARGO_PKG_NAME env var");
-        let crate_vers = env::var("CARGO_PKG_VERSION").expect("should have CARGO_PKG_VERSION env var");
-
-        let generated_static_name = format!(
-            "__WASM_BINDGEN_GENERATED_{}_{}_{}",
-            to_ident_name(&crate_name),
-            to_ident_name(&crate_vers),
-            CNT.fetch_add(1, Ordering::SeqCst)
-        );
-        let generated_static_name = syn::Ident::from(generated_static_name);
-
-        let mut generated_static_value = Tokens::new();
-        let generated_static_length = self.literal(&mut generated_static_value);
-
-        (my_quote! {
-            #[allow(non_upper_case_globals)]
-            #[wasm_custom_section = "__wasm_bindgen_unstable"]
-            const #generated_static_name: [u8; #generated_static_length] =
-                [#generated_static_value];
-        }).to_tokens(tokens);
-    }
-}
-
-impl ToTokens for ast::Struct {
-    fn to_tokens(&self, tokens: &mut Tokens) {
-        let name = &self.name;
-        let free_fn = syn::Ident::from(shared::free_function(self.name.as_ref()));
-        let c = shared::name_to_descriptor(name.as_ref()) as u32;
-        (my_quote! {
-            impl ::wasm_bindgen::convert::WasmBoundary for #name {
-                type Js = u32;
-                const DESCRIPTOR: u32 = #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: u32) {
-                <#name as ::wasm_bindgen::convert::WasmBoundary>::from_js(ptr);
-            }
-        }).to_tokens(tokens);
-    }
-}
-
-impl ToTokens for ast::Export {
-    fn to_tokens(self: &ast::Export, into: &mut Tokens) {
-        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 = syn::Ident::from("_ret");
-
-        let mut offset = 0;
-        if self.method {
-            let class = self.class.unwrap();
-            args.push(my_quote! { me: *mut ::wasm_bindgen::__rt::WasmRefCell<#class> });
-            arg_conversions.push(my_quote! {
-                ::wasm_bindgen::__rt::assert_not_null(me);
-                let me = unsafe { &*me };
-            });
-            offset = 1;
-        }
-
-        for (i, ty) in self.function.arguments.iter().enumerate() {
-            let i = i + offset;
-            let ident = syn::Ident::from(format!("arg{}", i));
-            match *ty {
-                ast::Type::Vector(ref ty, owned) => {
-                    let ptr = syn::Ident::from(format!("arg{}_ptr", i));
-                    let len = syn::Ident::from(format!("arg{}_len", i));
-                    let abi_ty = ty.abi_element();
-                    args.push(my_quote! { #ptr: *mut #abi_ty });
-                    args.push(my_quote! { #len: usize });
-                    if owned {
-                        arg_conversions.push(my_quote! {
-                            let #ident = unsafe {
-                                ::std::vec::Vec::from_raw_parts(#ptr, #len, #len)
-                            };
-                        });
-                    } else {
-                        arg_conversions.push(my_quote! {
-                            let #ident = unsafe {
-                                ::std::slice::from_raw_parts(#ptr as *const #abi_ty, #len)
-                            };
-                        });
-                    }
-                    if let ast::VectorType::String = *ty {
-                        if owned {
-                            arg_conversions.push(my_quote! {
-                                let #ident = unsafe {
-                                    ::std::string::String::from_utf8_unchecked(#ident)
-                                };
-                            });
-                        } else {
-                            arg_conversions.push(my_quote! {
-                                let #ident = unsafe {
-                                    ::std::str::from_utf8_unchecked(#ident)
-                                };
-                            });
-                        }
-                    }
-                }
-                ast::Type::ByValue(ref t) => {
-                    args.push(my_quote! {
-                        #ident: <#t as ::wasm_bindgen::convert::WasmBoundary >::Js
-                    });
-                    arg_conversions.push(my_quote! {
-                        let #ident = unsafe {
-                            <#t as ::wasm_bindgen::convert::WasmBoundary>
-                                ::from_js(#ident)
-                        };
-                    });
-                }
-                ast::Type::ByRef(ref ty) => {
-                    args.push(my_quote! {
-                        #ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
-                    });
-                    arg_conversions.push(my_quote! {
-                        let #ident = unsafe {
-                            <#ty as ::wasm_bindgen::convert::FromRefWasmBoundary>
-                                ::from_js_ref(#ident)
-                        };
-                        let #ident = &*#ident;
-                    });
-                }
-                ast::Type::ByMutRef(ref ty) => {
-                    args.push(my_quote! {
-                        #ident: <#ty as ::wasm_bindgen::convert::WasmBoundary>::Js
-                    });
-                    arg_conversions.push(my_quote! {
-                        let mut #ident = unsafe {
-                            <#ty as ::wasm_bindgen::convert::FromRefMutWasmBoundary>
-                                ::from_js_ref_mut(#ident)
-                        };
-                        let #ident = &mut *#ident;
-                    });
-                }
-            }
-            converted_arguments.push(my_quote! { #ident });
-        }
-        let ret_ty;
-        let convert_ret;
-        match self.function.ret {
-            Some(ast::Type::Vector(ref ty, true)) => {
-                ret_ty = my_quote! { -> *mut #ty };
-                convert_ret = my_quote! { Box::into_raw(Box::new(#ret)) };
-            }
-            Some(ast::Type::ByValue(ref t)) => {
-                ret_ty = my_quote! {
-                    -> <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
-                };
-                convert_ret = my_quote! {
-                    <#t as ::wasm_bindgen::convert::WasmBoundary>::into_js(#ret)
-                };
-            }
-            Some(ast::Type::Vector(_, false)) |
-            Some(ast::Type::ByMutRef(_)) |
-            Some(ast::Type::ByRef(_)) => {
-                panic!("can't return a borrowed ref");
-            }
-            None => {
-                ret_ty = my_quote! {};
-                convert_ret = my_quote! {};
-            }
-        }
-
-        let name = self.function.name;
-        let receiver = match self.class {
-            Some(_) if self.method => {
-                if self.mutable {
-                    my_quote! { me.borrow_mut().#name }
-                } else {
-                    my_quote! { me.borrow().#name }
-                }
-            }
-            Some(class) => my_quote! { #class::#name },
-            None => my_quote!{ #name },
-        };
-
-        let tokens = my_quote! {
-            #[export_name = #export_name]
-            #[allow(non_snake_case)]
-            pub extern fn #generated_name(#(#args),*) #ret_ty {
-                ::wasm_bindgen::__rt::link_this_library();
-                #(#arg_conversions)*
-                let #ret = #receiver(#(#converted_arguments),*);
-                #convert_ret
-            }
-        };
-        tokens.to_tokens(into);
-    }
-}
-
-impl ToTokens for ast::ImportType {
-    fn to_tokens(&self, tokens: &mut Tokens) {
-        let vis = &self.vis;
-        let name = &self.name;
-        (my_quote! {
-            #[allow(bad_style)]
-            #vis struct #name {
-                obj: ::wasm_bindgen::JsValue,
-            }
-
-            impl ::wasm_bindgen::convert::WasmBoundary for #name {
-                type Js = <::wasm_bindgen::JsValue as
-                    ::wasm_bindgen::convert::WasmBoundary>::Js;
-                const DESCRIPTOR: u32 = <::wasm_bindgen::JsValue as
-                    ::wasm_bindgen::convert::WasmBoundary>::DESCRIPTOR;
-
-                fn into_js(self) -> Self::Js {
-                    self.obj.into_js()
-                }
-
-                unsafe fn from_js(js: Self::Js) -> Self {
-                    #name { obj: ::wasm_bindgen::JsValue::from_js(js) }
-                }
-            }
-
-            impl ::wasm_bindgen::convert::ToRefWasmBoundary for #name {
-                fn to_js_ref(&self) -> u32 {
-                    self.obj.to_js_ref()
-                }
-            }
-
-            impl ::wasm_bindgen::convert::FromRefWasmBoundary for #name {
-                type RefAnchor = ::std::mem::ManuallyDrop<#name>;
-                unsafe fn from_js_ref(js: Self::Js) -> Self::RefAnchor {
-                    let obj = <::wasm_bindgen::JsValue as ::wasm_bindgen::convert::WasmBoundary>
-                        ::from_js(js);
-                    ::std::mem::ManuallyDrop::new(#name { obj })
-                }
-            }
-
-
-            impl From<::wasm_bindgen::JsValue> for #name {
-                fn from(obj: ::wasm_bindgen::JsValue) -> #name {
-                    #name { obj }
-                }
-            }
-
-            impl From<#name> for ::wasm_bindgen::JsValue {
-                fn from(obj: #name) -> ::wasm_bindgen::JsValue {
-                    obj.obj
-                }
-            }
-        }).to_tokens(tokens);
-    }
-}
-
-impl ToTokens for ast::ImportKind {
-    fn to_tokens(&self, tokens: &mut Tokens) {
-        match *self {
-            ast::ImportKind::Function(ref f) => f.to_tokens(tokens),
-            ast::ImportKind::Static(ref s) => s.to_tokens(tokens),
-            ast::ImportKind::Type(ref t) => t.to_tokens(tokens),
-        }
-    }
-}
-
-impl ToTokens for ast::ImportFunction {
-    fn to_tokens(&self, tokens: &mut Tokens) {
-        let mut class_ty = None;
-        let mut is_method = false;
-        match self.kind {
-            ast::ImportFunctionKind::Method { ref ty, .. } => {
-                is_method = true;
-                class_ty = Some(ty);
-            }
-            ast::ImportFunctionKind::JsConstructor { ref ty, .. } => {
-                class_ty = Some(ty);
-            }
-            ast::ImportFunctionKind::Normal => {}
-        }
-        let vis = &self.function.rust_vis;
-        let ret = &self.function.rust_decl.output;
-        let fn_token = &self.function.rust_decl.fn_token;
-
-        let mut abi_argument_names = Vec::new();
-        let mut abi_arguments = Vec::new();
-        let mut arg_conversions = Vec::new();
-        let ret_ident = syn::Ident::from("_ret");
-
-        let names = self.function.rust_decl.inputs
-            .iter()
-            .map(|arg| {
-                match *arg {
-                    syn::FnArg::Captured(ref c) => c,
-                    _ => panic!("arguments cannot be `self` or ignored"),
-                }
-            })
-            .map(|arg| {
-                match arg.pat {
-                    syn::Pat::Ident(syn::PatIdent {
-                        by_ref: None,
-                        ident,
-                        subpat: None,
-                        ..
-                    }) => {
-                        ident
-                    }
-                    _ => panic!("unsupported pattern in foreign function"),
-                }
-            });
-
-        for (i, (ty, name)) in self.function.arguments.iter().zip(names).enumerate() {
-            match *ty {
-                ast::Type::Vector(ref ty, owned) => {
-                    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);
-                    let abi_ty = ty.abi_element();
-                    abi_arguments.push(my_quote! { #ptr: *const #abi_ty });
-                    abi_arguments.push(my_quote! { #len: usize });
-                    arg_conversions.push(my_quote! {
-                        let #ptr = #name.as_ptr();
-                        let #len = #name.len();
-                    });
-                    if owned {
-                        arg_conversions.push(my_quote! { ::std::mem::forget(#name); });
-                    }
-                }
-                ast::Type::ByValue(ref t) => {
-                    abi_argument_names.push(name);
-                    abi_arguments.push(my_quote! {
-                        #name: <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
-                    });
-                    if i == 0 && is_method {
-                        arg_conversions.push(my_quote! {
-                            let #name = <#t as ::wasm_bindgen::convert::WasmBoundary>
-                                ::into_js(self);
-                        });
-                    } else {
-                        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 });
-                    if i == 0 && is_method {
-                        arg_conversions.push(my_quote! {
-                            let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
-                                ::to_js_ref(self);
-                        });
-                    } else {
-                        arg_conversions.push(my_quote! {
-                            let #name = <#t as ::wasm_bindgen::convert::ToRefWasmBoundary>
-                                ::to_js_ref(#name);
-                        });
-                    }
-                }
-            }
-        }
-        let abi_ret;
-        let mut convert_ret;
-        match self.function.ret {
-            Some(ast::Type::ByValue(ref t)) => {
-                abi_ret = my_quote! {
-                    <#t as ::wasm_bindgen::convert::WasmBoundary>::Js
-                };
-                convert_ret = my_quote! {
-                    <#t as ::wasm_bindgen::convert::WasmBoundary>::from_js(#ret_ident)
-                };
-            }
-
-            Some(ast::Type::Vector(ref ty, true)) => {
-                let name = syn::Ident::from("__ret_len");
-                let name_ptr = syn::Ident::from("__ret_len_ptr");
-                abi_argument_names.push(name_ptr);
-                abi_arguments.push(my_quote! { #name_ptr: *mut usize });
-                arg_conversions.push(my_quote! {
-                    let mut #name = 0;
-                    let mut #name_ptr = &mut #name as *mut usize;
-                });
-                let abi_ty = ty.abi_element();
-                abi_ret = my_quote! { *mut #abi_ty };
-                if let ast::VectorType::String = *ty {
-                    convert_ret = my_quote! {
-                        String::from_utf8_unchecked(
-                            Vec::from_raw_parts(#ret_ident, #name, #name)
-                        )
-                    };
-                } else {
-                    convert_ret = my_quote! {
-                        Vec::from_raw_parts(#ret_ident, #name, #name)
-                    };
-                }
-            }
-            Some(ast::Type::ByRef(_)) |
-            Some(ast::Type::Vector(_, false)) |
-            Some(ast::Type::ByMutRef(_)) => panic!("can't return a borrowed ref"),
-            None => {
-                abi_ret = my_quote! { () };
-                convert_ret = my_quote! { () };
-            }
-        }
-
-        let mut exceptional_ret = my_quote! {};
-        if self.function.opts.catch() {
-            let exn_data = syn::Ident::from("exn_data");
-            let exn_data_ptr = syn::Ident::from("exn_data_ptr");
-            abi_argument_names.push(exn_data_ptr);
-            abi_arguments.push(my_quote! { #exn_data_ptr: *mut u32 });
-            arg_conversions.push(my_quote! {
-                let mut #exn_data = [0; 2];
-                let #exn_data_ptr = #exn_data.as_mut_ptr();
-            });
-            convert_ret = my_quote! { Ok(#convert_ret) };
-            exceptional_ret = my_quote! {
-                if #exn_data[0] == 1 {
-                    return Err(<::wasm_bindgen::JsValue as
-                        ::wasm_bindgen::convert::WasmBoundary>::from_js(#exn_data[1]))
-                }
-            };
-        }
-
-        let rust_name = self.rust_name;
-        let import_name = self.shim;
-        let attrs = &self.function.rust_attrs;
-
-        let arguments = self.function.rust_decl.inputs
-            .iter()
-            .skip(if is_method { 1 } else { 0 })
-            .collect::<Vec<_>>();
-
-        let me = if is_method {
-            my_quote! { &self, }
-        } else {
-            quote!()
-        };
-
-        let invocation = my_quote! {
-            #(#attrs)*
-            #[allow(bad_style)]
-            #vis extern #fn_token #rust_name(#me #(#arguments),*) #ret {
-                ::wasm_bindgen::__rt::link_this_library();
-                #[wasm_import_module = "__wbindgen_placeholder__"]
-                extern {
-                    fn #import_name(#(#abi_arguments),*) -> #abi_ret;
-                }
-                unsafe {
-                    #(#arg_conversions)*
-                    let #ret_ident = #import_name(#(#abi_argument_names),*);
-                    #exceptional_ret
-                    #convert_ret
-                }
-            }
-        };
-
-        if let Some(class) = class_ty {
-            (quote! {
-                impl #class {
-                    #invocation
-                }
-            }).to_tokens(tokens);
-        } else {
-            invocation.to_tokens(tokens);
-        }
-    }
-}
-
-impl ToTokens for ast::Enum {
-    fn to_tokens(&self, into: &mut Tokens) {
-        let enum_name = &self.name;
-        let c = shared::TYPE_ENUM as u32;
-        let incoming_u32 = quote! { n };
-        let enum_name_as_string = enum_name.to_string();
-        let cast_clauses = self.variants.iter().map(|variant| {
-            let variant_name = &variant.name;
-            quote! {
-                if #incoming_u32 == #enum_name::#variant_name as u32 {
-                    #enum_name::#variant_name
-                }
-            }
-        });
-        (my_quote! {
-            impl #enum_name {
-                fn from_u32(#incoming_u32: u32) -> #enum_name {
-                    #(#cast_clauses else)* {
-                        wasm_bindgen::throw(&format!("Could not cast {} as {}", #incoming_u32, #enum_name_as_string));
-                    }
-                }
-            }
-
-            impl ::wasm_bindgen::convert::WasmBoundary for #enum_name {
-                type Js = u32;
-                const DESCRIPTOR: u32 = #c;
-
-                fn into_js(self) -> u32 {
-                    self as u32
-                }
-
-                unsafe fn from_js(js: u32) -> Self {
-                    #enum_name::from_u32(js)
-                }
-            }
-        }).to_tokens(into);
-    }
-}
-
-impl ToTokens for ast::ImportStatic {
-    fn to_tokens(&self, into: &mut Tokens) {
-        let name = self.rust_name;
-        let ty = &self.ty;
-        let shim_name = self.shim;
-        let vis = &self.vis;
-        (my_quote! {
-            #[allow(bad_style)]
-            #vis static #name: ::wasm_bindgen::JsStatic<#ty> = {
-                fn init() -> #ty {
-                    #[wasm_import_module = "__wbindgen_placeholder__"]
-                    extern {
-                        fn #shim_name() -> u32;
-                    }
-                    unsafe {
-                        ::wasm_bindgen::convert::WasmBoundary::from_js(#shim_name())
-                    }
-                }
-                ::wasm_bindgen::JsStatic {
-                    __inner: ::std::cell::UnsafeCell::new(None),
-                    __init: init,
-                }
-            };
-        }).to_tokens(into);
-    }
-}