Version 2.10.0-22.0.dev

Merge commit '7e42cbf5828ae800853c4baf1745d17ebc01bf2f' into 'dev'

Author: Dart CI

pkg/_fe_analyzer_shared/lib/src/parser/forwarding_listener.dart

@@ -1121,8 +1121,8 @@ class ForwardingListener implements Listener {
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
-    listener?.handleClassExtends(extendsKeyword);
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
+    listener?.handleClassExtends(extendsKeyword, typeCount);
   }
 
   @override

pkg/_fe_analyzer_shared/lib/src/parser/listener.dart

@@ -126,7 +126,10 @@ class Listener implements UnescapeErrorListener {
 
   /// Handle an extends clause in a class declaration. Substructures:
   /// - supertype (may be a mixin application)
-  void handleClassExtends(Token extendsKeyword) {
+  /// The typeCount is for error recovery: Invalid code might have more than one
+  /// class specified in the extends clause. A parser error has already been
+  /// issued.
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     logEvent("ClassExtends");
   }
 

pkg/_fe_analyzer_shared/lib/src/parser/parser_impl.dart

@@ -1903,10 +1903,7 @@ class Parser {
           const ['extend', 'on'].contains(token.next.lexeme)) {
         reportRecoverableError(
             token.next, codes.templateExpectedInstead.withArguments('extends'));
-        Token incorrectExtendsKeyword = token.next;
-        token = computeType(incorrectExtendsKeyword, /* required = */ true)
-            .ensureTypeNotVoid(incorrectExtendsKeyword, this);
-        listener.handleClassExtends(incorrectExtendsKeyword);
+        token = parseClassExtendsSeenExtendsClause(token.next, token);
       } else {
         token = parseClassExtendsOpt(token);
       }
@@ -1966,17 +1963,36 @@ class Parser {
     // extends <typeNotVoid>
     Token next = token.next;
     if (optional('extends', next)) {
-      Token extendsKeyword = next;
-      token = computeType(next, /* required = */ true)
-          .ensureTypeNotVoid(next, this);
-      listener.handleClassExtends(extendsKeyword);
+      token = parseClassExtendsSeenExtendsClause(next, token);
     } else {
       listener.handleNoType(token);
-      listener.handleClassExtends(/* extendsKeyword = */ null);
+      listener.handleClassExtends(null, 1);
     }
     return token;
   }
 
+  Token parseClassExtendsSeenExtendsClause(Token extendsKeyword, Token token) {
+    Token next = extendsKeyword;
+    token =
+        computeType(next, /* required = */ true).ensureTypeNotVoid(next, this);
+    int count = 1;
+
+    // Error recovery: extends <typeNotVoid>, <typeNotVoid> [...]
+    if (optional(',', token.next)) {
+      reportRecoverableError(token.next, codes.messageMultipleExtends);
+
+      while (optional(',', token.next)) {
+        next = token.next;
+        token = computeType(next, /* required = */ true)
+            .ensureTypeNotVoid(next, this);
+        count++;
+      }
+    }
+
+    listener.handleClassExtends(extendsKeyword, count);
+    return token;
+  }
+
   /// ```
   /// implementsClause:
   ///   'implements' typeName (',' typeName)*

pkg/_fe_analyzer_shared/lib/src/parser/recovery_listeners.dart

@@ -18,9 +18,9 @@ class ClassHeaderRecoveryListener extends ForwardingListener {
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     this.extendsKeyword = extendsKeyword;
-    super.handleClassExtends(extendsKeyword);
+    super.handleClassExtends(extendsKeyword, typeCount);
   }
 
   @override

pkg/_fe_analyzer_shared/lib/src/parser/stack_listener.dart

@@ -306,7 +306,7 @@ abstract class StackListener extends Listener {
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     debugEvent("ClassExtends");
   }
 

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -2447,10 +2447,16 @@ class AstBuilder extends StackListener {
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     assert(extendsKeyword == null || extendsKeyword.isKeywordOrIdentifier);
     debugEvent("ClassExtends");
 
+    // If more extends clauses was specified (parser has already issued an
+    // error) throw them away for now and pick the first one.
+    while (typeCount > 1) {
+      pop();
+      typeCount--;
+    }
     TypeName supertype = pop();
     if (supertype != null) {
       push(ast.extendsClause(extendsKeyword, supertype));

pkg/analyzer/test/generated/parser_fasta_listener.dart

@@ -1260,9 +1260,9 @@ class ForwardingTestListener extends ForwardingListener {
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     expectIn('ClassDeclaration');
-    listener.handleClassExtends(extendsKeyword);
+    listener.handleClassExtends(extendsKeyword, typeCount);
   }
 
   @override

pkg/front_end/lib/src/fasta/source/outline_builder.dart

@@ -522,6 +522,11 @@ class OutlineBuilder extends StackListenerImpl {
   @override
   void handleRecoverClassHeader() {
     debugEvent("handleRecoverClassHeader");
+    // TODO(jensj): Possibly use these instead... E.g. "class A extend B {}"
+    // will get here (because it's 'extends' with an 's') and discard the B...
+    // Also Analyzer actually merges the information meaning that the two could
+    // give different errors (if, say, one later assigns
+    // A to a variable of type B).
     pop(NullValue.TypeBuilderList); // Interfaces.
     pop(); // Supertype offset.
     pop(); // Supertype.
@@ -530,13 +535,19 @@ class OutlineBuilder extends StackListenerImpl {
   @override
   void handleRecoverMixinHeader() {
     debugEvent("handleRecoverMixinHeader");
+    // TODO(jensj): Possibly use these instead...
+    // See also handleRecoverClassHeader
     pop(NullValue.TypeBuilderList); // Interfaces.
     pop(NullValue.TypeBuilderList); // Supertype constraints.
   }
 
   @override
-  void handleClassExtends(Token extendsKeyword) {
+  void handleClassExtends(Token extendsKeyword, int typeCount) {
     debugEvent("handleClassExtends");
+    while (typeCount > 1) {
+      pop();
+      typeCount--;
+    }
     push(extendsKeyword?.charOffset ?? -1);
   }
 

pkg/front_end/messages.status

@@ -481,8 +481,6 @@ MixinFunction/script: Fail # TODO(johnniwinther): This message is currently igno
 MixinInferenceNoMatchingClass/example: Fail
 ModifierOutOfOrder/part_wrapped_script1: Fail
 ModifierOutOfOrder/script1: Fail
-MultipleExtends/part_wrapped_script: Fail
-MultipleExtends/script: Fail
 MultipleImplements/part_wrapped_script: Fail
 MultipleImplements/script: Fail
 MultipleLibraryDirectives/example: Fail

pkg/front_end/messages.yaml

@@ -366,7 +366,9 @@ MultipleExtends:
   template: "Each class definition can have at most one extends clause."
   tip: "Try choosing one superclass and define your class to implement (or mix in) the others."
   analyzerCode: ParserErrorCode.MULTIPLE_EXTENDS_CLAUSES
-  script: "class A extends B extends C {}"
+  script:
+    - "class B{} class C{} class A extends B extends C {}"
+    - "class B{} class C{} class A extends B, C {}"
 
 MultipleWith:
   index: 24