Move some utility functions from the webidl crate into the backend crate

crates/backend/src/ast.rs

@@ -1,8 +1,8 @@
 use proc_macro2::{Ident, Span, TokenStream, TokenTree};
 use quote::ToTokens;
 use shared;
-use std::iter::FromIterator;
 use syn;
+use util;
 
 #[cfg_attr(feature = "extra-traits", derive(Debug, PartialEq, Eq))]
 #[derive(Default)]
@@ -416,20 +416,7 @@ impl Program {
         } else if let Some(cls) = wasm.opts.static_method_of() {
             let class = cls.to_string();
             let kind = MethodKind::Static;
-
-            let segments = syn::punctuated::Punctuated::from_iter(Some(syn::PathSegment {
-                ident: cls.clone(),
-                arguments: syn::PathArguments::None,
-            }));
-
-            let ty = syn::Type::Path(syn::TypePath {
-                qself: None,
-                path: syn::Path {
-                    leading_colon: None,
-                    segments,
-                },
-            });
-
+            let ty = util::ident_ty(cls.clone());
             ImportFunctionKind::Method { class, ty, kind }
         } else if wasm.opts.constructor() {
             let class = match wasm.ret {

crates/backend/src/lib.rs

@@ -12,3 +12,4 @@ extern crate wasm_bindgen_shared as shared;
 
 pub mod ast;
 mod codegen;
+pub mod util;

crates/backend/src/util.rs

@@ -0,0 +1,69 @@
+use std::iter::FromIterator;
+
+use ast;
+use proc_macro2::{self, Ident};
+use syn;
+
+fn is_rust_keyword(name: &str) -> bool {
+    match name {
+        "abstract" | "alignof" | "as" | "become" | "box" | "break" | "const" | "continue"
+        | "crate" | "do" | "else" | "enum" | "extern" | "false" | "final" | "fn" | "for" | "if"
+        | "impl" | "in" | "let" | "loop" | "macro" | "match" | "mod" | "move" | "mut"
+        | "offsetof" | "override" | "priv" | "proc" | "pub" | "pure" | "ref" | "return"
+        | "Self" | "self" | "sizeof" | "static" | "struct" | "super" | "trait" | "true"
+        | "type" | "typeof" | "unsafe" | "unsized" | "use" | "virtual" | "where" | "while"
+        | "yield" | "bool" | "_" => true,
+        _ => false,
+    }
+}
+
+// Create an `Ident`, possibly mangling it if it conflicts with a Rust keyword.
+pub fn rust_ident(name: &str) -> Ident {
+    if is_rust_keyword(name) {
+        Ident::new(&format!("{}_", name), proc_macro2::Span::call_site())
+    } else {
+        raw_ident(name)
+    }
+}
+
+// Create an `Ident` without checking to see if it conflicts with a Rust
+// keyword.
+pub fn raw_ident(name: &str) -> Ident {
+    Ident::new(name, proc_macro2::Span::call_site())
+}
+
+/// Create a path type from the given segments. For example an iterator yielding
+/// the idents `[foo, bar, baz]` will result in the path type `foo::bar::baz`.
+pub fn simple_path_ty<I>(segments: I) -> syn::Type
+where
+    I: IntoIterator<Item = Ident>,
+{
+    let segments: Vec<_> = segments
+        .into_iter()
+        .map(|i| syn::PathSegment {
+            ident: i,
+            arguments: syn::PathArguments::None,
+        })
+        .collect();
+
+    syn::TypePath {
+        qself: None,
+        path: syn::Path {
+            leading_colon: None,
+            segments: syn::punctuated::Punctuated::from_iter(segments),
+        },
+    }.into()
+}
+
+pub fn ident_ty(ident: Ident) -> syn::Type {
+    simple_path_ty(Some(ident))
+}
+
+pub fn wrap_import_function(function: ast::ImportFunction) -> ast::Import {
+    ast::Import {
+        module: None,
+        version: None,
+        js_namespace: None,
+        kind: ast::ImportKind::Function(function),
+    }
+}