If an if or do statement always exits, following statements are dead.

pkg/analyzer/test/generated/hint_code_test.dart

Index: pkg/analyzer/test/generated/hint_code_test.dart
diff --git a/pkg/analyzer/test/generated/hint_code_test.dart b/pkg/analyzer/test/generated/hint_code_test.dart
index bc5c9829dd2dfc060ebf4a60ee98ad0fe4af944d..585f24d4e725bc9d037427ec6c659c5c9c618ddb 100644
--- a/pkg/analyzer/test/generated/hint_code_test.dart
+++ b/pkg/analyzer/test/generated/hint_code_test.dart
@@ -619,6 +619,105 @@ f() {
     verify([source]);
   }
 
+  void test_deadCode_statementAfterExitingIf_function() {

[Brian Wilkerson, 2016/05/04 17:28:19]

If ExitDetector worked, then most of these tests could be moved to be unit tests
for ExitDetector.

[srawlins, 2016/05/19 18:36:44]

You're right. Dramatically reduced tests!

+    Source source = addSource(r'''
+f() {
+  if (1 > 2) {
+    return;
+  } else {
+    return;
+  }
+  var two = 2;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingIf_returns() {
+    Source source = addSource(r'''
+f() {
+  if (1 > 2) {
+    return;
+  } else {
+    return;
+  }
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingIf_throws() {
+    Source source = addSource(r'''
+f() {
+  if (1 > 2) {
+    throw 'Stopping in then';
+  } else {
+    throw 'Stopping in else';
+  }
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingIf_loops() {
+    Source source = addSource(r'''
+f() {
+  if (1 > 2) {
+    while (true) { print('Hello'); }
+  } else {
+    while (true) { print('Hello'); }
+  }
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingDo_returns() {
+    Source source = addSource(r'''
+f() {
+  do {
+    return;
+  } while (1 < 0);
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingDo_throws() {
+    Source source = addSource(r'''
+f() {
+  do {
+    throw 'me';
+  } while (1 < 0);
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
+  void test_deadCode_statementAfterExitingDo_loops() {
+    Source source = addSource(r'''
+f() {
+  do {
+    while (true) print('Hello');
+  } while (1 < 0);
+  var one = 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [HintCode.DEAD_CODE]);
+    verify([source]);
+  }
+
   void test_deprecatedAnnotationUse_assignment() {
     Source source = addSource(r'''
 class A {