Initial commit

crates/wasm-bindgen-macro/src/ast.rs

@@ -0,0 +1,151 @@
+use proc_macro2::Literal;
+use quote::{ToTokens, Tokens};
+use serde_json;
+use syn;
+use wasm_bindgen_shared as shared;
+
+pub struct Function {
+    pub name: syn::Ident,
+    pub arguments: Vec<Type>,
+    pub ret: Option<Type>,
+}
+
+pub enum Type {
+    Integer(syn::Ident),
+}
+
+impl Function {
+    pub fn from(input: &syn::ItemFn) -> Function {
+        match input.vis {
+            syn::Visibility::Public(_) => {}
+            _ => panic!("can only bindgen public functions"),
+        }
+        match input.constness {
+            syn::Constness::NotConst => {}
+            _ => panic!("can only bindgen non-const functions"),
+        }
+        match input.unsafety {
+            syn::Unsafety::Normal => {}
+            _ => panic!("can only bindgen safe functions"),
+        }
+        if !input.abi.is_none() {
+            panic!("can only bindgen Rust ABI functions")
+        }
+        if !input.abi.is_none() {
+            panic!("can only bindgen Rust ABI functions")
+        }
+        if input.decl.variadic {
+            panic!("can't bindgen variadic functions")
+        }
+        if input.decl.generics.params.len() > 0 {
+            panic!("can't bindgen functions with lifetime or type parameters")
+        }
+
+        let arguments = input.decl.inputs.iter()
+            .map(|i| i.into_item())
+            .map(|arg| {
+                match *arg {
+                    syn::FnArg::Captured(ref c) => c,
+                    _ => panic!("arguments cannot be `self` or ignored"),
+                }
+            })
+            .map(|arg| Type::from(&arg.ty))
+            .collect::<Vec<_>>();
+
+        let ret = match input.decl.output {
+            syn::ReturnType::Default => None,
+            syn::ReturnType::Type(ref t, _) => Some(Type::from(t)),
+        };
+
+        Function {
+            name: input.ident,
+            arguments,
+            ret,
+        }
+    }
+
+    pub fn export_name(&self) -> syn::Lit {
+        syn::Lit {
+            value: syn::LitKind::Other(Literal::string(self.name.sym.as_str())),
+            span: Default::default(),
+        }
+    }
+
+    pub fn rust_symbol(&self) -> syn::Ident {
+        let generated_name = format!("__wasm_bindgen_generated_{}",
+                                     self.name.sym.as_str());
+        syn::Ident::from(generated_name)
+    }
+
+    pub fn generated_static_name(&self) -> syn::Ident {
+        let generated_name = format!("__WASM_BINDGEN_GENERATED_{}",
+                                     self.name.sym.as_str());
+        syn::Ident::from(generated_name)
+    }
+
+    pub fn generate_static(&self) -> Vec<u8> {
+        let mut prefix = String::from("wbg:");
+        prefix.push_str(&serde_json::to_string(&self.shared()).unwrap());
+        prefix.into_bytes()
+    }
+
+    fn shared(&self) -> shared::Function {
+        shared::Function {
+            name: self.name.sym.as_str().to_string(),
+            arguments: self.arguments.iter().map(|t| t.shared()).collect(),
+            ret: self.ret.as_ref().map(|t| t.shared()),
+        }
+    }
+}
+
+impl Type {
+    pub fn from(ty: &syn::Type) -> Type {
+        match *ty {
+            // syn::Type::Reference(ref r) => {
+            // }
+            syn::Type::Path(syn::TypePath { qself: None, ref path }) => {
+                if path.leading_colon.is_some() {
+                    panic!("unsupported leading colon in path")
+                }
+                if path.segments.len() != 1 {
+                    panic!("unsupported path that needs name resolution")
+                }
+                match path.segments.get(0).item().arguments {
+                    syn::PathArguments::None => {}
+                    _ => panic!("unsupported path that has path arguments")
+                }
+                let ident = path.segments.get(0).item().ident;
+                match ident.sym.as_str() {
+                    "i8" |
+                    "u8" |
+                    "u16" |
+                    "i16" |
+                    "u32" |
+                    "i32" |
+                    "isize" |
+                    "usize" |
+                    "f32" |
+                    "f64" => {
+                        Type::Integer(ident)
+                    }
+                    s => panic!("unsupported type: {}", s),
+                }
+            }
+            _ => panic!("unsupported type"),
+        }
+    }
+
+    fn shared(&self) -> shared::Type {
+        match *self {
+            Type::Integer(_) => shared::Type::Number,
+        }
+    }
+}
+
+impl ToTokens for Type {
+    fn to_tokens(&self, tokens: &mut Tokens) {
+        match *self {
+            Type::Integer(i) => i.to_tokens(tokens),
+        }
+    }
+}