Add label support to ExitDetector

pkg/analyzer/test/generated/all_the_rest_test.dart

Index: pkg/analyzer/test/generated/all_the_rest_test.dart
diff --git a/pkg/analyzer/test/generated/all_the_rest_test.dart b/pkg/analyzer/test/generated/all_the_rest_test.dart
index c01ed0b03b5f083b124ead1acd302bc892ba0ed1..9445d72b08eedd4c524fc3f9efee7015eca2f02f 100644
--- a/pkg/analyzer/test/generated/all_the_rest_test.dart
+++ b/pkg/analyzer/test/generated/all_the_rest_test.dart
@@ -3856,6 +3856,20 @@ class ExitDetectorTest extends ParserTestCase {
  */
 @reflectiveTest
 class ExitDetectorTest2 extends ResolverTestCase {
+  void test_forStatement_implicitTrue_breakWithLabel() {
+    Source source = addSource(r'''
+void f() {
+  x: for (;;) {
+    if (1 < 2) {
+      break x;
+    }
+    return;
+  }
+}
+''');
+    _assertNthStatementDoesNotExit(source, 0);
+  }
+
   void test_switch_withEnum_false_noDefault() {
     Source source = addSource(r'''
 enum E { A, B }
@@ -3870,12 +3884,7 @@ String f(E e) {
   return x;
 }
 ''');
-    LibraryElement element = resolve2(source);
-    CompilationUnit unit = resolveCompilationUnit(source, element);
-    FunctionDeclaration function = unit.declarations.last;
-    BlockFunctionBody body = function.functionExpression.body;
-    Statement statement = body.block.statements[1];
-    expect(ExitDetector.exits(statement), false);
+    _assertNthStatementDoesNotExit(source, 1);
   }
 
   void test_switch_withEnum_false_withDefault() {
@@ -3892,12 +3901,7 @@ String f(E e) {
   return x;
 }
 ''');
-    LibraryElement element = resolve2(source);
-    CompilationUnit unit = resolveCompilationUnit(source, element);
-    FunctionDeclaration function = unit.declarations.last;
-    BlockFunctionBody body = function.functionExpression.body;
-    Statement statement = body.block.statements[1];
-    expect(ExitDetector.exits(statement), false);
+    _assertNthStatementDoesNotExit(source, 1);
   }
 
   void test_switch_withEnum_true_noDefault() {
@@ -3912,12 +3916,7 @@ String f(E e) {
   }
 }
 ''');
-    LibraryElement element = resolve2(source);
-    CompilationUnit unit = resolveCompilationUnit(source, element);
-    FunctionDeclaration function = unit.declarations.last;
-    BlockFunctionBody body = function.functionExpression.body;
-    Statement statement = body.block.statements[0];
-    expect(ExitDetector.exits(statement), true);
+    _assertNthStatementExits(source, 0);
   }
 
   void test_switch_withEnum_true_withDefault() {
@@ -3932,12 +3931,56 @@ String f(E e) {
   }
 }
 ''');
+    _assertNthStatementExits(source, 0);
+  }
+
+  void test_whileStatement_breakWithLabel() {
+    Source source = addSource(r'''
+void f() {
+  x: while (true) {
+    if (1 < 2) {
+      break x;
+    }
+    return;
+  }
+}
+''');
+    _assertNthStatementDoesNotExit(source, 0);
+  }
+
+  void test_whileStatement_breakWithLabel_afterExting() {
+    Source source = addSource(r'''
+void f() {
+  x: while (true) {
+    return;
+    if (1 < 2) {
+      break x;
+    }
+  }
+}
+''');
+    _assertNthStatementExits(source, 0);
+  }
+
+  void _assertHasReturn(bool expectedResult, String source, int n) {
     LibraryElement element = resolve2(source);
     CompilationUnit unit = resolveCompilationUnit(source, element);
     FunctionDeclaration function = unit.declarations.last;
     BlockFunctionBody body = function.functionExpression.body;
-    Statement statement = body.block.statements[0];
-    expect(ExitDetector.exits(statement), true);
+    Statement statement = body.block.statements[n];
+    expect(ExitDetector.exits(statement), expectedResult);
+  }
+
+  // Assert that the [n]th statement in the last function declaration of
+  // [source] exits.
+  void _assertNthStatementExits(String source, int n) {
+    _assertHasReturn(true, source, n);
+  }
+
+  // Assert that the [n]th statement in the last function declaration of
+  // [source] does not exit.
+  void _assertNthStatementDoesNotExit(String source, int n) {
+    _assertHasReturn(false, source, n);
   }
 }