Move #[css(iterable)] on fields rather than variants

components/style/counter_style/mod.rs

@@ -547,9 +547,8 @@ impl Parse for Fallback {
 
 /// <https://drafts.csswg.org/css-counter-styles/#descdef-counter-style-symbols>
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[css(iterable)]
 #[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
-pub struct Symbols(pub Vec<Symbol>);
+pub struct Symbols(#[css(iterable)] pub Vec<Symbol>);
 
 impl Parse for Symbols {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {

components/style/media_queries.rs

@@ -25,10 +25,11 @@ pub use gecko::media_queries::{Device, Expression};
 
 /// A type that encapsulates a media query list.
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
-#[css(comma, iterable)]
+#[css(comma)]
 #[derive(Clone, Debug, ToCss)]
 pub struct MediaList {
     /// The list of media queries.
+    #[css(iterable)]
     pub media_queries: Vec<MediaQuery>,
 }
 

components/style/properties/helpers.mako.rs

@@ -126,9 +126,7 @@
             % endif
             % if not allow_empty:
             % if separator == "Comma":
-            #[css(comma, iterable)]
+            #[css(comma)]
-            % else:
-            #[css(iterable)]
             % endif
             #[derive(ToCss)]
             % endif
@@ -136,6 +134,9 @@
                 % if allow_empty and allow_empty != "NotInitial":
                 pub Vec<single_value::T>,
                 % else:
+                % if not allow_empty:
+                #[css(iterable)]
+                % endif
                 pub SmallVec<[single_value::T; 1]>,
                 % endif
             );
@@ -189,13 +190,16 @@
         #[derive(Clone, Debug, MallocSizeOf, PartialEq)]
         % if not allow_empty:
         % if separator == "Comma":
-        #[css(comma, iterable)]
+        #[css(comma)]
-        % else:
-        #[css(iterable)]
         % endif
         #[derive(ToCss)]
         % endif
-        pub struct SpecifiedValue(pub Vec<single_value::SpecifiedValue>);
+        pub struct SpecifiedValue(
+            % if not allow_empty:
+            #[css(iterable)]
+            % endif
+            pub Vec<single_value::SpecifiedValue>,
+        );
 
         % if allow_empty:
         impl ToCss for SpecifiedValue {

components/style/stylesheets/document_rule.rs

@@ -176,9 +176,9 @@ impl UrlMatchingFunction {
 /// The `@document` rule's condition is written as a comma-separated list of
 /// URL matching functions, and the condition evaluates to true whenever any
 /// one of those functions evaluates to true.
-#[css(comma, iterable)]
+#[css(comma)]
 #[derive(Clone, Debug, ToCss)]
-pub struct DocumentCondition(Vec<UrlMatchingFunction>);
+pub struct DocumentCondition(#[css(iterable)] Vec<UrlMatchingFunction>);
 
 impl DocumentCondition {
     /// Parse a document condition.

components/style/stylesheets/font_feature_values_rule.rs

@@ -118,9 +118,8 @@ impl ToGeckoFontFeatureValues for PairValues {
 }
 
 /// A @font-feature-values block declaration value that keeps a list of values.
-#[css(iterable)]
 #[derive(Clone, Debug, PartialEq, ToCss)]
-pub struct VectorValues(pub Vec<u32>);
+pub struct VectorValues(#[css(iterable)] pub Vec<u32>);
 
 impl Parse for VectorValues {
     fn parse<'i, 't>(_context: &ParserContext, input: &mut Parser<'i, 't>)

components/style/stylesheets/keyframes_rule.rs

@@ -145,9 +145,9 @@ impl KeyframePercentage {
 
 /// A keyframes selector is a list of percentages or from/to symbols, which are
 /// converted at parse time to percentages.
-#[css(comma, iterable)]
+#[css(comma)]
 #[derive(Clone, Debug, Eq, PartialEq, ToCss)]
-pub struct KeyframeSelector(Vec<KeyframePercentage>);
+pub struct KeyframeSelector(#[css(iterable)] Vec<KeyframePercentage>);
 
 impl KeyframeSelector {
     /// Return the list of percentages this selector contains.

components/style/values/specified/box.rs

@@ -369,9 +369,9 @@ pub enum OverflowClipBox {
 pub enum WillChange {
     /// Expresses no particular intent
     Auto,
-    #[css(comma, iterable)]
     /// <custom-ident>
-    AnimateableFeatures(Box<[CustomIdent]>),
+    #[css(comma)]
+    AnimateableFeatures(#[css(iterable)] Box<[CustomIdent]>),
 }
 
 impl WillChange {

components/style/values/specified/counters.rs

@@ -92,8 +92,7 @@ pub enum Content {
     #[cfg(feature = "gecko")]
     MozAltContent,
     /// Content items.
-    #[css(iterable)]
+    Items(#[css(iterable)] Box<[ContentItem]>),
-    Items(Box<[ContentItem]>),
 }
 
 /// Items for the `content` property.

components/style/values/specified/font.rs

@@ -152,8 +152,8 @@ impl From<LengthOrPercentage> for FontSize {
 #[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss)]
 pub enum FontFamily {
     /// List of `font-family`
-    #[css(iterable, comma)]
+    #[css(comma)]
-    Values(FontFamilyList),
+    Values(#[css(iterable)] FontFamilyList),
     /// System font
     System(SystemFont),
 }
@@ -718,11 +718,11 @@ pub enum VariantAlternates {
     #[css(function)]
     Stylistic(CustomIdent),
     /// Enables display with stylistic sets
-    #[css(comma, function, iterable)]
+    #[css(comma, function)]
-    Styleset(Box<[CustomIdent]>),
+    Styleset(#[css(iterable)] Box<[CustomIdent]>),
     /// Enables display of specific character variants
-    #[css(comma, function, iterable)]
+    #[css(comma, function)]
-    CharacterVariant(Box<[CustomIdent]>),
+    CharacterVariant(#[css(iterable)] Box<[CustomIdent]>),
     /// Enables display of swash glyphs
     #[css(function)]
     Swash(CustomIdent),

components/style_derive/to_css.rs

@@ -4,7 +4,7 @@
 
 use cg::{self, WhereClause};
 use darling::util::Override;
-use quote::Tokens;
+use quote::{ToTokens, Tokens};
 use syn::{self, Data};
 use synstructure::{Structure, VariantInfo};
 
@@ -18,7 +18,6 @@ pub fn derive(input: syn::DeriveInput) -> Tokens {
     if let Data::Enum(_) = input.data {
         assert!(input_attrs.function.is_none(), "#[css(function)] is not allowed on enums");
         assert!(!input_attrs.comma, "#[css(comma)] is not allowed on enums");
-        assert!(!input_attrs.iterable, "#[css(iterable)] is not allowed on enums");
     }
     let s = Structure::new(&input);
 
@@ -86,30 +85,24 @@ fn derive_variant_arm(
         }
     } else if !bindings.is_empty() {
         let mut expr = quote! {};
-        if variant_attrs.iterable {
-            assert_eq!(bindings.len(), 1);
-            let binding = &bindings[0];
-            expr = quote! {
-                #expr
-
-                for item in #binding.iter() {
-                    writer.item(&item)?;
-                }
-            };
-        } else {
         for binding in bindings {
             let attrs = cg::parse_field_attrs::<CssFieldAttrs>(&binding.ast());
             if attrs.skip {
                 continue;
             }
+            let variant_expr = if attrs.iterable {
+                quote! {
+                    for item in #binding.iter() {
+                        writer.item(&item)?;
+                    }
+                }
+            } else {
                 if !attrs.ignore_bound {
                     where_clause.add_trait_bound(&binding.ast().ty);
                 }
-                expr = quote! {
+                quote!{ writer.item(#binding)?; }
-                    #expr
-                    writer.item(#binding)?;
             };
-            }
+            variant_expr.to_tokens(&mut expr)
         }
 
         quote! {{
@@ -148,15 +141,12 @@ struct CssInputAttrs {
     function: Option<Override<String>>,
     // Here because structs variants are also their whole type definition.
     comma: bool,
-    // Here because structs variants are also their whole type definition.
-    iterable: bool,
 }
 
 #[darling(attributes(css), default)]
 #[derive(Default, FromVariant)]
 pub struct CssVariantAttrs {
     pub function: Option<Override<String>>,
-    pub iterable: bool,
     pub comma: bool,
     pub dimension: bool,
     pub keyword: Option<String>,
@@ -167,5 +157,6 @@ pub struct CssVariantAttrs {
 #[derive(Default, FromField)]
 struct CssFieldAttrs {
     ignore_bound: bool,
+    iterable: bool,
     skip: bool,
 }