Merge pull request #792 from afdw/master

Add support for variadic arguments in WebIDL

crates/cli-support/src/js/rust2js.rs

@@ -499,13 +499,26 @@ impl<'a, 'b> Rust2Js<'a, 'b> {
                 return Err(failure::err_msg("a function with no arguments cannot be variadic"));
             }
             let last_arg = self.js_arguments.len() - 1; // check implies >= 0
-            self.ret_expr.replace(
-                "JS",
-                &format!("{}({}, ...{})",
-                         invoc,
-                         self.js_arguments[..last_arg].join(", "),
-                         self.js_arguments[last_arg])
-            )
+            if self.js_arguments.len() != 1 {
+                self.ret_expr.replace(
+                    "JS",
+                    &format!(
+                        "{}({}, ...{})",
+                        invoc,
+                        self.js_arguments[..last_arg].join(", "),
+                        self.js_arguments[last_arg],
+                    )
+                )
+            } else {
+                self.ret_expr.replace(
+                    "JS",
+                    &format!(
+                        "{}(...{})",
+                        invoc,
+                        self.js_arguments[last_arg],
+                    )
+                )
+            }
         } else {
             self.ret_expr.replace(
                 "JS",

crates/webidl-tests/simple.js

@@ -110,6 +110,13 @@ global.OptionalAndUnionArguments = class OptionalAndUnionArguments {
   }
 };
 
+global.Variadic = class Variadic {
+  constructor() {}
+  sum(...values) {
+    return values.reduce((a, b) => a + b, 0);
+  }
+};
+
 global.PartialInterface = class PartialInterface {
   get un() {
     return 1;

crates/webidl-tests/simple.rs

@@ -94,6 +94,24 @@ fn optional_and_union_arguments() {
     assert_eq!(f.m_with_b_and_str_and_opt_bool("abc", false, "5", Some(true)), "string, abc, boolean, false, string, 5, boolean, true");
 }
 
+#[wasm_bindgen_test]
+fn variadic() {
+    let f = Variadic::new().unwrap();
+    assert_eq!(f.sum_5(1, 2, 3, 4, 5), 15);
+    assert_eq!(
+        f.sum(
+            &::js_sys::Array::of5(
+                &JsValue::from_f64(1f64),
+                &JsValue::from_f64(2f64),
+                &JsValue::from_f64(3f64),
+                &JsValue::from_f64(4f64),
+                &JsValue::from_f64(5f64),
+            )
+        ),
+        15
+    );
+}
+
 #[wasm_bindgen_test]
 fn unforgeable_is_structural() {
     let f = Unforgeable::new().unwrap();

crates/webidl-tests/simple.webidl

@@ -57,6 +57,11 @@ interface OptionalAndUnionArguments {
   );
 };
 
+[Constructor()]
+interface Variadic {
+  short sum(short... values);
+};
+
 [Constructor()]
 interface Unforgeable {
   [Unforgeable] readonly attribute short uno;

crates/webidl/src/first_pass.rs

@@ -95,18 +95,19 @@ pub(crate) struct OperationData<'src> {
     pub(crate) is_static: bool,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub(crate) struct Signature<'src> {
     pub(crate) args: Vec<Arg<'src>>,
     pub(crate) ret: weedle::types::ReturnType<'src>,
     pub(crate) attrs: &'src Option<ExtendedAttributeList<'src>>,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub(crate) struct Arg<'src> {
     pub(crate) name: &'src str,
     pub(crate) ty: &'src weedle::types::Type<'src>,
     pub(crate) optional: bool,
+    pub(crate) variadic: bool,
 }
 
 /// Implemented on an AST node to populate the `FirstPassRecord` struct.
@@ -258,19 +259,17 @@ fn first_pass_operation<'src>(
     };
     let mut args = Vec::with_capacity(arguments.len());
     for argument in arguments {
-        let arg = match argument {
-            Argument::Single(single) => single,
-            Argument::Variadic(v) => {
-                warn!("Unsupported variadic argument {} in {}",
-                      v.identifier.0,
-                      self_name);
-                return
-            }
+        let (name, ty, optional, variadic) = match argument {
+            Argument::Single(single) =>
+                (single.identifier.0, &single.type_.type_, single.optional.is_some(), false),
+            Argument::Variadic(variadic) =>
+                (variadic.identifier.0, &variadic.type_, false, true),
         };
         args.push(Arg {
-            name: arg.identifier.0,
-            ty: &arg.type_.type_,
-            optional: arg.optional.is_some(),
+            name,
+            ty,
+            optional,
+            variadic,
         });
     }
     for id in ids {

crates/webidl/src/lib.rs

@@ -142,7 +142,7 @@ fn builtin_idents() -> BTreeSet<Ident> {
         vec![
             "str", "char", "bool", "JsValue", "u8", "i8", "u16", "i16", "u32", "i32", "u64", "i64",
             "usize", "isize", "f32", "f64", "Result", "String", "Vec", "Option",
-            "ArrayBuffer", "Object", "Promise", "Function",
+            "Array", "ArrayBuffer", "Object", "Promise", "Function",
         ].into_iter()
             .map(|id| proc_macro2::Ident::new(id, proc_macro2::Span::call_site())),
     )

crates/webidl/src/util.rs

@@ -13,6 +13,12 @@ use weedle::literal::{ConstValue, FloatLit, IntegerLit};
 use first_pass::{FirstPassRecord, OperationId, OperationData, Signature};
 use idl_type::{IdlType, ToIdlType};
 
+/// For variadic operations an overload with a `js_sys::Array` argument is generated alongside with
+/// `operation_name_0`, `operation_name_1`, `operation_name_2`, ..., `operation_name_n` overloads
+/// which have the count of arguments for passing values to the variadic argument
+/// in their names, where `n` is this constant.
+const MAX_VARIADIC_ARGUMENTS_COUNT: usize = 7;
+
 /// Take a type and create an immutable shared reference to that type.
 pub(crate) fn shared_ref(ty: syn::Type, mutable: bool) -> syn::Type {
     syn::TypeReference {
@@ -223,6 +229,7 @@ impl<'src> FirstPassRecord<'src> {
         kind: backend::ast::ImportFunctionKind,
         structural: bool,
         catch: bool,
+        variadic: bool,
         doc_comment: Option<String>,
     ) -> Option<backend::ast::ImportFunction> where 'src: 'a {
         // Convert all of the arguments from their IDL type to a `syn` type,
@@ -245,7 +252,9 @@ impl<'src> FirstPassRecord<'src> {
         } else {
             Vec::with_capacity(idl_arguments.size_hint().0)
         };
-        for (argument_name, idl_type) in idl_arguments {
+        let idl_arguments: Vec<_> = idl_arguments.collect();
+        let arguments_count = idl_arguments.len();
+        for (i, (argument_name, idl_type)) in idl_arguments.into_iter().enumerate() {
             let syn_type = match idl_type.to_syn_type(TypePosition::Argument) {
                 Some(t) => t,
                 None => {
@@ -257,6 +266,12 @@ impl<'src> FirstPassRecord<'src> {
                     return None
                 }
             };
+            let syn_type = if variadic && i == arguments_count - 1 {
+                let path = vec![rust_ident("js_sys"), rust_ident("Array")];
+                shared_ref(leading_colon_path_ty(path), false)
+            } else {
+                syn_type
+            };
             let argument_name = rust_ident(&argument_name.to_snake_case());
             arguments.push(simple_fn_arg(argument_name, syn_type));
         }
@@ -296,10 +311,10 @@ impl<'src> FirstPassRecord<'src> {
             },
             rust_name: rust_ident(rust_name),
             js_ret: js_ret.clone(),
-            variadic: false,
+            variadic,
             catch,
             structural,
-            shim:{
+            shim: {
                 let ns = match kind {
                     backend::ast::ImportFunctionKind::ScopedMethod { .. } |
                     backend::ast::ImportFunctionKind::Normal => "",
@@ -334,7 +349,8 @@ impl<'src> FirstPassRecord<'src> {
             kind,
             is_structural(attrs.as_ref(), container_attrs),
             throws(attrs),
-            Some(format!("The `{}` getter\n\n{}", name, mdn_doc(self_name, Some(name))))
+            false,
+            Some(format!("The `{}` getter\n\n{}", name, mdn_doc(self_name, Some(name)))),
         )
     }
 
@@ -360,7 +376,8 @@ impl<'src> FirstPassRecord<'src> {
             kind,
             is_structural(attrs.as_ref(), container_attrs),
             throws(attrs),
-            Some(format!("The `{}` setter\n\n{}", name, mdn_doc(self_name, Some(name))))
+            false,
+            Some(format!("The `{}` setter\n\n{}", name, mdn_doc(self_name, Some(name)))),
         )
     }
 
@@ -413,7 +430,14 @@ impl<'src> FirstPassRecord<'src> {
             let mut idl_args = Vec::with_capacity(signature.args.len());
             for (i, arg) in signature.args.iter().enumerate() {
                 if arg.optional {
-                    assert!(signature.args[i..].iter().all(|a| a.optional));
+                    assert!(
+                        signature
+                            .args[i..]
+                            .iter()
+                            .all(|arg| arg.optional || arg.variadic),
+                        "Not optional or variadic argument after optional argument: {:?}",
+                        signature.args,
+                    );
                     signatures.push((signature, idl_args.clone()));
                 }
                 match arg.ty.to_idl_type(self) {
@@ -559,18 +583,47 @@ impl<'src> FirstPassRecord<'src> {
                     rust_name.push_str(&snake_case_ident(arg_name));
                 }
             }
+            let structural = force_structural || is_structural(signature.orig.attrs.as_ref(), container_attrs);
+            let catch = force_throws || throws(&signature.orig.attrs);
+            let variadic = signature.args.len() == signature.orig.args.len()
+                && signature.orig.args.last().map(|arg| arg.variadic).unwrap_or(false);
             ret.extend(self.create_one_function(
                 name,
                 &rust_name,
                 signature.args.iter()
                     .zip(&signature.orig.args)
-                    .map(|(ty, orig_arg)| (orig_arg.name, ty)),
+                    .map(|(idl_type, orig_arg)| (orig_arg.name, idl_type)),
                 &ret_ty,
                 kind.clone(),
-                force_structural || is_structural(signature.orig.attrs.as_ref(), container_attrs),
-                force_throws || throws(&signature.orig.attrs),
+                structural,
+                catch,
+                variadic,
                 None,
             ));
+            if !variadic {
+                continue;
+            }
+            let last_idl_type = &signature.args[signature.args.len() - 1];
+            let last_name = signature.orig.args[signature.args.len() - 1].name;
+            for i in 0..=MAX_VARIADIC_ARGUMENTS_COUNT {
+                ret.extend(self.create_one_function(
+                    name,
+                    &format!("{}_{}", rust_name, i),
+                    signature.args[..signature.args.len() - 1].iter()
+                        .zip(&signature.orig.args)
+                        .map(|(idl_type, orig_arg)| (orig_arg.name.to_string(), idl_type))
+                        .chain((1..=i).map(|j| (format!("{}_{}", last_name, j), last_idl_type)))
+                        .collect::<Vec<_>>()
+                        .iter()
+                        .map(|(name, idl_type)| (&name[..], idl_type.clone())),
+                    &ret_ty,
+                    kind.clone(),
+                    structural,
+                    catch,
+                    false,
+                    None,
+                ));
+            }
         }
         return ret;
     }