Auto merge of #19397 - cbrewster:create_element_for_token, r=jdm,nox

Implement the create an element for token algorithm

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #19392 and fix #19393 (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19397)
<!-- Reviewable:end -->

components/script/dom/bindings/settings_stack.rs

@@ -35,6 +35,12 @@ pub unsafe fn trace(tracer: *mut JSTracer) {
     })
 }
 
+pub fn is_execution_stack_empty() -> bool {
+    STACK.with(|stack| {
+        stack.borrow().is_empty()
+    })
+}
+
 /// RAII struct that pushes and pops entries from the script settings stack.
 pub struct AutoEntryScript {
     global: DomRoot<GlobalScope>,

components/script/dom/document.rs

@@ -364,6 +364,8 @@ pub struct Document {
     tti_window: DomRefCell<InteractiveWindow>,
     /// RAII canceller for Fetch
     canceller: FetchCanceller,
+    /// https://html.spec.whatwg.org/multipage/#throw-on-dynamic-markup-insertion-counter
+    throw_on_dynamic_markup_insertion_counter: Cell<u64>,
 }
 
 #[derive(JSTraceable, MallocSizeOf)]
@@ -1894,7 +1896,12 @@ impl Document {
 
     pub fn can_invoke_script(&self) -> bool {
         match self.get_current_parser() {
-            Some(parser) => parser.parser_is_not_active(),
+            Some(parser) => {
+                // It is safe to run script if the parser is not actively parsing,
+                // or if it is impossible to interact with the token stream.
+                parser.parser_is_not_active() ||
+                self.throw_on_dynamic_markup_insertion_counter.get() > 0
+            }
             None => true,
         }
     }
@@ -2053,6 +2060,16 @@ impl Document {
         let global_scope = self.window.upcast::<GlobalScope>();
         global_scope.script_to_constellation_chan().send(msg).unwrap();
     }
+
+    pub fn increment_throw_on_dynamic_markup_insertion_counter(&self) {
+        let counter = self.throw_on_dynamic_markup_insertion_counter.get();
+        self.throw_on_dynamic_markup_insertion_counter.set(counter + 1);
+    }
+
+    pub fn decrement_throw_on_dynamic_markup_insertion_counter(&self) {
+        let counter = self.throw_on_dynamic_markup_insertion_counter.get();
+        self.throw_on_dynamic_markup_insertion_counter.set(counter - 1);
+    }
 }
 
 #[derive(MallocSizeOf, PartialEq)]
@@ -2294,6 +2311,7 @@ impl Document {
             interactive_time: DomRefCell::new(interactive_time),
             tti_window: DomRefCell::new(InteractiveWindow::new()),
             canceller: canceller,
+            throw_on_dynamic_markup_insertion_counter: Cell::new(0),
         }
     }
 
@@ -3717,7 +3735,9 @@ impl DocumentMethods for Document {
         }
 
         // Step 2.
-        // TODO: handle throw-on-dynamic-markup-insertion counter.
+        if self.throw_on_dynamic_markup_insertion_counter.get() > 0 {
+            return Err(Error::InvalidState);
+        }
 
         if !self.is_active() {
             // Step 3.
@@ -3863,7 +3883,10 @@ impl DocumentMethods for Document {
         }
 
         // Step 2.
-        // TODO: handle throw-on-dynamic-markup-insertion counter.
+        if self.throw_on_dynamic_markup_insertion_counter.get() > 0 {
+            return Err(Error::InvalidState);
+        }
+
         if !self.is_active() {
             // Step 3.
             return Ok(());
@@ -3910,7 +3933,9 @@ impl DocumentMethods for Document {
         }
 
         // Step 2.
-        // TODO: handle throw-on-dynamic-markup-insertion counter.
+        if self.throw_on_dynamic_markup_insertion_counter.get() > 0 {
+            return Err(Error::InvalidState);
+        }
 
         let parser = match self.get_current_parser() {
             Some(ref parser) if parser.is_script_created() => DomRoot::from_ref(&**parser),

components/script/dom/servoparser/async_html.rs

@@ -12,14 +12,15 @@ use dom::bindings::str::DOMString;
 use dom::comment::Comment;
 use dom::document::Document;
 use dom::documenttype::DocumentType;
-use dom::element::{CustomElementCreationMode, Element, ElementCreator};
+use dom::element::{Element, ElementCreator};
 use dom::htmlformelement::{FormControlElementHelpers, HTMLFormElement};
 use dom::htmlscriptelement::HTMLScriptElement;
 use dom::htmltemplateelement::HTMLTemplateElement;
 use dom::node::Node;
 use dom::processinginstruction::ProcessingInstruction;
+use dom::servoparser::{ElementAttribute, create_element_for_token, ParsingAlgorithm};
 use dom::virtualmethods::vtable_for;
-use html5ever::{Attribute as HtmlAttribute, ExpandedName, LocalName, QualName};
+use html5ever::{Attribute as HtmlAttribute, ExpandedName, QualName};
 use html5ever::buffer_queue::BufferQueue;
 use html5ever::tendril::{SendTendril, StrTendril, Tendril};
 use html5ever::tendril::fmt::UTF8;
@@ -335,20 +336,18 @@ impl Tokenizer {
                 self.insert_node(contents, Dom::from_ref(template.Content().upcast()));
             }
             ParseOperation::CreateElement { node, name, attrs, current_line } => {
-                let is = attrs.iter()
-                              .find(|attr| attr.name.local.eq_str_ignore_ascii_case("is"))
-                              .map(|attr| LocalName::from(&*attr.value));
-
-                let elem = Element::create(name,
-                                           is,
-                                           &*self.document,
-                                           ElementCreator::ParserCreated(current_line),
-                                           CustomElementCreationMode::Synchronous);
-                for attr in attrs {
-                    elem.set_attribute_from_parser(attr.name, DOMString::from(attr.value), None);
-                }
-
-                self.insert_node(node, Dom::from_ref(elem.upcast()));
+                let attrs = attrs
+                    .into_iter()
+                    .map(|attr| ElementAttribute::new(attr.name, DOMString::from(attr.value)))
+                    .collect();
+                let element = create_element_for_token(
+                    name,
+                    attrs,
+                    &*self.document,
+                    ElementCreator::ParserCreated(current_line),
+                    ParsingAlgorithm::Normal
+                );
+                self.insert_node(node, Dom::from_ref(element.upcast()));
             }
             ParseOperation::CreateComment { text, node } => {
                 let comment = Comment::new(DOMString::from(text), document);

components/script/dom/servoparser/html.rs

@@ -16,7 +16,7 @@ use dom::htmlscriptelement::HTMLScriptElement;
 use dom::htmltemplateelement::HTMLTemplateElement;
 use dom::node::Node;
 use dom::processinginstruction::ProcessingInstruction;
-use dom::servoparser::Sink;
+use dom::servoparser::{ParsingAlgorithm, Sink};
 use html5ever::QualName;
 use html5ever::buffer_queue::BufferQueue;
 use html5ever::serialize::{AttrRef, Serialize, Serializer};
@@ -39,13 +39,15 @@ impl Tokenizer {
     pub fn new(
             document: &Document,
             url: ServoUrl,
-            fragment_context: Option<super::FragmentContext>)
+            fragment_context: Option<super::FragmentContext>,
+            parsing_algorithm: ParsingAlgorithm)
             -> Self {
         let sink = Sink {
             base_url: url,
             document: Dom::from_ref(document),
             current_line: 1,
             script: Default::default(),
+            parsing_algorithm: parsing_algorithm,
         };
 
         let options = TreeBuilderOpts {

components/script/dom/servoparser/mod.rs

@@ -13,6 +13,7 @@ use dom::bindings::inheritance::Castable;
 use dom::bindings::refcounted::Trusted;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot, MutNullableDom, RootedReference};
+use dom::bindings::settings_stack::is_execution_stack_empty;
 use dom::bindings::str::DOMString;
 use dom::characterdata::CharacterData;
 use dom::comment::Comment;
@@ -101,6 +102,26 @@ enum LastChunkState {
     NotReceived,
 }
 
+pub struct ElementAttribute {
+    name: QualName,
+    value: DOMString
+}
+
+#[derive(Clone, Copy, JSTraceable, MallocSizeOf, PartialEq)]
+pub enum ParsingAlgorithm {
+    Normal,
+    Fragment,
+}
+
+impl ElementAttribute {
+    pub fn new(name: QualName, value: DOMString) -> ElementAttribute {
+        ElementAttribute {
+            name: name,
+            value: value
+        }
+    }
+}
+
 impl ServoParser {
     pub fn parser_is_not_active(&self) -> bool {
         self.can_write() || self.tokenizer.try_borrow_mut().is_ok()
@@ -114,7 +135,7 @@ impl ServoParser {
                              ParserKind::Normal)
         } else {
             ServoParser::new(document,
-                             Tokenizer::Html(self::html::Tokenizer::new(document, url, None)),
+                             Tokenizer::Html(self::html::Tokenizer::new(document, url, None, ParsingAlgorithm::Normal)),
                              LastChunkState::NotReceived,
                              ParserKind::Normal)
         };
@@ -160,7 +181,8 @@ impl ServoParser {
         let parser = ServoParser::new(&document,
                                       Tokenizer::Html(self::html::Tokenizer::new(&document,
                                                                                  url,
-                                                                                 Some(fragment_context))),
+                                                                                 Some(fragment_context),
+                                                                                 ParsingAlgorithm::Fragment)),
                                       LastChunkState::Received,
                                       ParserKind::Normal);
         parser.parse_string_chunk(String::from(input));
@@ -173,10 +195,17 @@ impl ServoParser {
     }
 
     pub fn parse_html_script_input(document: &Document, url: ServoUrl, type_: &str) {
-        let parser = ServoParser::new(document,
-                                      Tokenizer::Html(self::html::Tokenizer::new(document, url, None)),
-                                      LastChunkState::NotReceived,
-                                      ParserKind::ScriptCreated);
+        let parser = ServoParser::new(
+            document,
+            Tokenizer::Html(self::html::Tokenizer::new(
+                document,
+                url,
+                None,
+                ParsingAlgorithm::Normal,
+            )),
+            LastChunkState::NotReceived,
+            ParserKind::ScriptCreated,
+        );
         document.set_current_parser(Some(&parser));
         if !type_.eq_ignore_ascii_case("text/html") {
             parser.parse_string_chunk("<pre>\n".to_owned());
@@ -748,6 +777,7 @@ pub struct Sink {
     document: Dom<Document>,
     current_line: u64,
     script: MutNullableDom<HTMLScriptElement>,
+    parsing_algorithm: ParsingAlgorithm,
 }
 
 impl Sink {
@@ -795,21 +825,18 @@ impl TreeSink for Sink {
 
     fn create_element(&mut self, name: QualName, attrs: Vec<Attribute>, _flags: ElementFlags)
             -> Dom<Node> {
-        let is = attrs.iter()
-                      .find(|attr| attr.name.local.eq_str_ignore_ascii_case("is"))
-                      .map(|attr| LocalName::from(&*attr.value));
-
-        let elem = Element::create(name,
-                                   is,
-                                   &*self.document,
-                                   ElementCreator::ParserCreated(self.current_line),
-                                   CustomElementCreationMode::Synchronous);
-
-        for attr in attrs {
-            elem.set_attribute_from_parser(attr.name, DOMString::from(String::from(attr.value)), None);
-        }
-
-        Dom::from_ref(elem.upcast())
+        let attrs = attrs
+            .into_iter()
+            .map(|attr| ElementAttribute::new(attr.name, DOMString::from(String::from(attr.value))))
+            .collect();
+        let element = create_element_for_token(
+            name,
+            attrs,
+            &*self.document,
+            ElementCreator::ParserCreated(self.current_line),
+            self.parsing_algorithm,
+        );
+        Dom::from_ref(element.upcast())
     }
 
     fn create_comment(&mut self, text: StrTendril) -> Dom<Node> {
@@ -950,3 +977,64 @@ impl TreeSink for Sink {
         vtable_for(&node).pop();
     }
 }
+
+/// https://html.spec.whatwg.org/multipage/#create-an-element-for-the-token
+fn create_element_for_token(
+    name: QualName,
+    attrs: Vec<ElementAttribute>,
+    document: &Document,
+    creator: ElementCreator,
+    parsing_algorithm: ParsingAlgorithm,
+) -> DomRoot<Element> {
+    // Step 3.
+    let is = attrs.iter()
+        .find(|attr| attr.name.local.eq_str_ignore_ascii_case("is"))
+        .map(|attr| LocalName::from(&*attr.value));
+
+    // Step 4.
+    let definition = document.lookup_custom_element_definition(&name.ns, &name.local, is.as_ref());
+
+    // Step 5.
+    let will_execute_script = definition.is_some() && parsing_algorithm != ParsingAlgorithm::Fragment;
+
+    // Step 6.
+    if will_execute_script {
+        // Step 6.1.
+        document.increment_throw_on_dynamic_markup_insertion_counter();
+        // Step 6.2
+        if is_execution_stack_empty() {
+            document.window().upcast::<GlobalScope>().perform_a_microtask_checkpoint();
+        }
+        // Step 6.3
+        ScriptThread::push_new_element_queue()
+    }
+
+    // Step 7.
+    let creation_mode = if will_execute_script {
+        CustomElementCreationMode::Synchronous
+    } else {
+        CustomElementCreationMode::Asynchronous
+    };
+    let element = Element::create(name, is, document, creator, creation_mode);
+
+    // Step 8.
+    for attr in attrs {
+        element.set_attribute_from_parser(attr.name, attr.value, None);
+    }
+
+    // Step 9.
+    if will_execute_script {
+        // Steps 9.1 - 9.2.
+        ScriptThread::pop_current_element_queue();
+        // Step 9.3.
+        document.decrement_throw_on_dynamic_markup_insertion_counter();
+    }
+
+    // TODO: Step 10.
+    // TODO: Step 11.
+
+    // Step 12 is handled in `associate_with_form`.
+
+    // Step 13.
+    element
+}

components/script/dom/servoparser/xml.rs

@@ -9,7 +9,7 @@ use dom::bindings::trace::JSTraceable;
 use dom::document::Document;
 use dom::htmlscriptelement::HTMLScriptElement;
 use dom::node::Node;
-use dom::servoparser::Sink;
+use dom::servoparser::{ParsingAlgorithm, Sink};
 use js::jsapi::JSTracer;
 use servo_url::ServoUrl;
 use xml5ever::buffer_queue::BufferQueue;
@@ -30,6 +30,7 @@ impl Tokenizer {
             document: Dom::from_ref(document),
             current_line: 1,
             script: Default::default(),
+            parsing_algorithm: ParsingAlgorithm::Normal,
         };
 
         let tb = XmlTreeBuilder::new(sink, Default::default());

tests/wpt/metadata/custom-elements/microtasks-and-constructors.html.ini

@@ -1,3 +0,0 @@
-[microtasks-and-constructors.html]
-  expected: CRASH
-  bug: https://github.com/servo/servo/issues/19392

tests/wpt/metadata/custom-elements/parser/parser-fallsback-to-unknown-element.html.ini

@@ -1,3 +0,0 @@
-[parser-fallsback-to-unknown-element.html]
-  expected: CRASH
-  bug: https://github.com/servo/servo/issues/19392