diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index bdddd9717da..eeece1cb86c 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -501,6 +501,7 @@ if (is_win) {
   default_warning_flags += [
     # Permanent.
     "/wd4091",  # typedef warning from dbghelp.h
+    "/wd4722",  # destructor never returns
 
     # Investigate.
     "/wd4312",  # int to pointer of greater size conversion.
diff --git a/runtime/bin/console_posix.cc b/runtime/bin/console_posix.cc
index 61fd677dd77..af28e153e6c 100644
--- a/runtime/bin/console_posix.cc
+++ b/runtime/bin/console_posix.cc
@@ -88,5 +88,5 @@ void Console::RestoreConfig() {
 }  // namespace bin
 }  // namespace dart
 
-#endif  // defined(HOST_OS_LINUX) || defined(HOST_OS_MACOS) ||                 \
+#endif  // defined(HOST_OS_LINUX) || defined(HOST_OS_MACOS) ||
         // defined(HOST_OS_ANDROID) || defined(HOST_OS_FUCHSIA)
diff --git a/runtime/bin/run_vm_tests.cc b/runtime/bin/run_vm_tests.cc
index b89697800f0..9d08b5dca09 100644
--- a/runtime/bin/run_vm_tests.cc
+++ b/runtime/bin/run_vm_tests.cc
@@ -297,7 +297,7 @@ static int Main(int argc, const char** argv) {
     OS::PrintErr("No tests matched: %s\n", run_filter);
     return 1;
   }
-  if (DynamicAssertionHelper::failed()) {
+  if (Expect::failed()) {
     return 255;
   }
   return 0;
diff --git a/runtime/platform/assert.cc b/runtime/platform/assert.cc
index fb7cc8876d4..262548eed19 100644
--- a/runtime/platform/assert.cc
+++ b/runtime/platform/assert.cc
@@ -10,9 +10,9 @@
 
 namespace dart {
 
-bool DynamicAssertionHelper::failed_ = false;
+bool Expect::failed_ = false;
 
-void DynamicAssertionHelper::Fail(const char* format, ...) {
+void DynamicAssertionHelper::Print(const char* format, va_list arguments) {
   // Take only the last 1KB of the file name if it is longer.
   const intptr_t file_len = strlen(file_);
   const intptr_t file_offset = (file_len > (1 * KB)) ? file_len - (1 * KB) : 0;
@@ -25,22 +25,32 @@ void DynamicAssertionHelper::Fail(const char* format, ...) {
       snprintf(buffer, sizeof(buffer), "%s: %d: error: ", file, line_);
 
   // Print the error message into the buffer.
-  va_list arguments;
-  va_start(arguments, format);
   vsnprintf(buffer + file_and_line_length,
             sizeof(buffer) - file_and_line_length, format, arguments);
-  va_end(arguments);
 
   // Print the buffer on stderr and/or syslog.
   OS::PrintErr("%s\n", buffer);
+}
 
-  // In case of failed assertions, abort right away. Otherwise, wait
-  // until the program is exiting before producing a non-zero exit
+void Assert::Fail(const char* format, ...) {
+  va_list arguments;
+  va_start(arguments, format);
+  Print(format, arguments);
+  va_end(arguments);
+
+  // Abort right away.
+  NOT_IN_PRODUCT(Dart_DumpNativeStackTrace(NULL));
+  OS::Abort();
+}
+
+void Expect::Fail(const char* format, ...) {
+  va_list arguments;
+  va_start(arguments, format);
+  Print(format, arguments);
+  va_end(arguments);
+
+  // Wait until the program is exiting before producing a non-zero exit
   // code through abort.
-  if (kind_ == ASSERT) {
-    NOT_IN_PRODUCT(Dart_DumpNativeStackTrace(NULL));
-    OS::Abort();
-  }
   failed_ = true;
 }
 
diff --git a/runtime/platform/assert.h b/runtime/platform/assert.h
index 1b01b736b10..48d1443c443 100644
--- a/runtime/platform/assert.h
+++ b/runtime/platform/assert.h
@@ -26,15 +26,34 @@ namespace dart {
 
 class DynamicAssertionHelper {
  public:
-  enum Kind { ASSERT, EXPECT };
+  DynamicAssertionHelper(const char* file, int line)
+      : file_(file), line_(line) {}
 
-  DynamicAssertionHelper(const char* file, int line, Kind kind)
-      : file_(file), line_(line), kind_(kind) {}
+ protected:
+  void Print(const char* format, va_list arguments);
+
+  const char* const file_;
+  const int line_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(DynamicAssertionHelper);
+};
+
+class Assert : public DynamicAssertionHelper {
+ public:
+  Assert(const char* file, int line) : DynamicAssertionHelper(file, line) {}
+
+  DART_NORETURN void Fail(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
+
+  template <typename T>
+  T NotNull(const T p);
+};
+
+class Expect : public DynamicAssertionHelper {
+ public:
+  Expect(const char* file, int line) : DynamicAssertionHelper(file, line) {}
 
   void Fail(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
 
-  static bool failed() { return failed_; }
-
 #if defined(TESTING)
   template <typename E, typename A>
   void Equals(const E& expected, const A& actual);
@@ -65,38 +84,29 @@ class DynamicAssertionHelper {
 
   template <typename E, typename A>
   void GreaterEqual(const E& left, const A& right);
-#endif
 
   template <typename T>
   T NotNull(const T p);
+#endif
+
+  static bool failed() { return failed_; }
 
  private:
   static bool failed_;
-
-  const char* const file_;
-  const int line_;
-  const Kind kind_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(DynamicAssertionHelper);
 };
 
-class Assert : public DynamicAssertionHelper {
- public:
-  Assert(const char* file, int line)
-      : DynamicAssertionHelper(file, line, ASSERT) {}
-};
-
-class Expect : public DynamicAssertionHelper {
- public:
-  Expect(const char* file, int line)
-      : DynamicAssertionHelper(file, line, EXPECT) {}
-};
+template <typename T>
+T Assert::NotNull(const T p) {
+  if (p != NULL) return p;
+  Fail("expected: not NULL, found NULL");
+  return NULL;
+}
 
 #if defined(TESTING)
 // Only allow the expensive (with respect to code size) assertions
 // in testing code.
 template <typename E, typename A>
-void DynamicAssertionHelper::Equals(const E& expected, const A& actual) {
+void Expect::Equals(const E& expected, const A& actual) {
   if (actual == expected) return;
   std::ostringstream ess, ass;
   ess << expected;
@@ -106,7 +116,7 @@ void DynamicAssertionHelper::Equals(const E& expected, const A& actual) {
 }
 
 template <typename E, typename A>
-void DynamicAssertionHelper::NotEquals(const E& not_expected, const A& actual) {
+void Expect::NotEquals(const E& not_expected, const A& actual) {
   if (actual != not_expected) return;
   std::ostringstream ness;
   ness << not_expected;
@@ -115,9 +125,7 @@ void DynamicAssertionHelper::NotEquals(const E& not_expected, const A& actual) {
 }
 
 template <typename E, typename A, typename T>
-void DynamicAssertionHelper::FloatEquals(const E& expected,
-                                         const A& actual,
-                                         const T& tol) {
+void Expect::FloatEquals(const E& expected, const A& actual, const T& tol) {
   if (((expected - tol) <= actual) && (actual <= (expected + tol))) {
     return;
   }
@@ -131,8 +139,8 @@ void DynamicAssertionHelper::FloatEquals(const E& expected,
 }
 
 template <typename E, typename A>
-NO_SANITIZE_MEMORY void DynamicAssertionHelper::StringEquals(const E& expected,
-                                                             const A& actual) {
+NO_SANITIZE_MEMORY void Expect::StringEquals(const E& expected,
+                                             const A& actual) {
   std::ostringstream ess, ass;
   ess << expected;
   ass << actual;
@@ -142,8 +150,8 @@ NO_SANITIZE_MEMORY void DynamicAssertionHelper::StringEquals(const E& expected,
 }
 
 template <typename E, typename A>
-NO_SANITIZE_MEMORY void DynamicAssertionHelper::IsSubstring(const E& needle,
-                                                            const A& haystack) {
+NO_SANITIZE_MEMORY void Expect::IsSubstring(const E& needle,
+                                            const A& haystack) {
   std::ostringstream ess, ass;
   ess << needle;
   ass << haystack;
@@ -154,9 +162,8 @@ NO_SANITIZE_MEMORY void DynamicAssertionHelper::IsSubstring(const E& needle,
 }
 
 template <typename E, typename A>
-NO_SANITIZE_MEMORY void DynamicAssertionHelper::IsNotSubstring(
-    const E& needle,
-    const A& haystack) {
+NO_SANITIZE_MEMORY void Expect::IsNotSubstring(const E& needle,
+                                               const A& haystack) {
   std::ostringstream ess, ass;
   ess << needle;
   ass << haystack;
@@ -167,7 +174,7 @@ NO_SANITIZE_MEMORY void DynamicAssertionHelper::IsNotSubstring(
 }
 
 template <typename E, typename A>
-void DynamicAssertionHelper::LessThan(const E& left, const A& right) {
+void Expect::LessThan(const E& left, const A& right) {
   if (left < right) return;
   std::ostringstream ess, ass;
   ess << left;
@@ -177,7 +184,7 @@ void DynamicAssertionHelper::LessThan(const E& left, const A& right) {
 }
 
 template <typename E, typename A>
-void DynamicAssertionHelper::LessEqual(const E& left, const A& right) {
+void Expect::LessEqual(const E& left, const A& right) {
   if (left <= right) return;
   std::ostringstream ess, ass;
   ess << left;
@@ -187,7 +194,7 @@ void DynamicAssertionHelper::LessEqual(const E& left, const A& right) {
 }
 
 template <typename E, typename A>
-void DynamicAssertionHelper::GreaterThan(const E& left, const A& right) {
+void Expect::GreaterThan(const E& left, const A& right) {
   if (left > right) return;
   std::ostringstream ess, ass;
   ess << left;
@@ -197,7 +204,7 @@ void DynamicAssertionHelper::GreaterThan(const E& left, const A& right) {
 }
 
 template <typename E, typename A>
-void DynamicAssertionHelper::GreaterEqual(const E& left, const A& right) {
+void Expect::GreaterEqual(const E& left, const A& right) {
   if (left >= right) return;
   std::ostringstream ess, ass;
   ess << left;
@@ -205,14 +212,14 @@ void DynamicAssertionHelper::GreaterEqual(const E& left, const A& right) {
   std::string es = ess.str(), as = ass.str();
   Fail("expected: %s >= %s", es.c_str(), as.c_str());
 }
-#endif
 
 template <typename T>
-T DynamicAssertionHelper::NotNull(const T p) {
+T Expect::NotNull(const T p) {
   if (p != NULL) return p;
   Fail("expected: not NULL, found NULL");
   return NULL;
 }
+#endif
 
 }  // namespace dart
 
diff --git a/runtime/platform/utils.cc b/runtime/platform/utils.cc
index c53af65eb9a..205cafc9f46 100644
--- a/runtime/platform/utils.cc
+++ b/runtime/platform/utils.cc
@@ -78,8 +78,10 @@ uint32_t Utils::StringHash(const char* data, int length) {
   switch (size) {
     case 3:
       hash ^= cursor[2] << 16;
+      /* Falls through. */
     case 2:
       hash ^= cursor[1] << 8;
+      /* Falls through. */
     case 1:
       hash ^= cursor[0];
       hash *= M;
diff --git a/runtime/vm/ast.cc b/runtime/vm/ast.cc
index e7e74bc7f30..08def4b46ad 100644
--- a/runtime/vm/ast.cc
+++ b/runtime/vm/ast.cc
@@ -314,7 +314,7 @@ bool BinaryOpNode::IsPotentiallyConst() const {
           this->right()->AsLiteralNode()->literal().IsNull()) {
         return false;
       }
-    // Fall-through intentional.
+      /* Falls through */
     case Token::kADD:
     case Token::kSUB:
     case Token::kMUL:
@@ -353,7 +353,7 @@ const Instance* BinaryOpNode::EvalConstExpr() const {
       if (left_val->IsString()) {
         return right_val->IsString() ? left_val : NULL;
       }
-    // Fall-through intentional.
+      /* Falls through */
     case Token::kSUB:
     case Token::kMUL:
     case Token::kDIV:
diff --git a/runtime/vm/compiler/backend/il.h b/runtime/vm/compiler/backend/il.h
index 62ebc72e621..2fee1fcd7bb 100644
--- a/runtime/vm/compiler/backend/il.h
+++ b/runtime/vm/compiler/backend/il.h
@@ -3263,7 +3263,10 @@ class InstanceCallInstr : public TemplateDartCall<0> {
   CompileType* result_type() const { return result_type_; }
 
   intptr_t result_cid() const {
-    return (result_type_ != NULL) ? result_type_->ToCid() : kDynamicCid;
+    if (result_type_ == NULL) {
+      return kDynamicCid;
+    }
+    return result_type_->ToCid();
   }
 
   PRINT_OPERANDS_TO_SUPPORT
@@ -3759,7 +3762,10 @@ class StaticCallInstr : public TemplateDartCall<0> {
   CompileType* result_type() const { return result_type_; }
 
   intptr_t result_cid() const {
-    return (result_type_ != NULL) ? result_type_->ToCid() : kDynamicCid;
+    if (result_type_ == NULL) {
+      return kDynamicCid;
+    }
+    return result_type_->ToCid();
   }
 
   bool is_known_list_constructor() const { return is_known_list_constructor_; }
diff --git a/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc b/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
index 943119a2077..9d3d8898138 100644
--- a/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
+++ b/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
@@ -38,43 +38,55 @@ void FunctionNodeHelper::ReadUntilExcluding(Field field) {
       ASSERT(tag == kFunctionNode);
       if (++next_read_ == field) return;
     }
+    /* Falls through */
     case kPosition:
       position_ = helper_->ReadPosition();  // read position.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEndPosition:
       end_position_ = helper_->ReadPosition();  // read end position.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAsyncMarker:
       async_marker_ = static_cast<AsyncMarker>(helper_->ReadByte());
       if (++next_read_ == field) return;
+      /* Falls through */
     case kDartAsyncMarker:
       dart_async_marker_ = static_cast<AsyncMarker>(
           helper_->ReadByte());  // read dart async marker.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kTypeParameters:
       helper_->SkipTypeParametersList();  // read type parameters.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kTotalParameterCount:
       total_parameter_count_ =
           helper_->ReadUInt();  // read total parameter count.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kRequiredParameterCount:
       required_parameter_count_ =
           helper_->ReadUInt();  // read required parameter count.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kPositionalParameters:
       helper_->SkipListOfVariableDeclarations();  // read positionals.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kNamedParameters:
       helper_->SkipListOfVariableDeclarations();  // read named.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kReturnType:
       helper_->SkipDartType();  // read return type.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kBody:
       if (helper_->ReadTag() == kSomething)
         helper_->SkipStatement();  // read body.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -114,25 +126,32 @@ void VariableDeclarationHelper::ReadUntilExcluding(Field field) {
     case kPosition:
       position_ = helper_->ReadPosition();  // read position.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEqualPosition:
       equals_position_ = helper_->ReadPosition();  // read equals position.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations:
       helper_->SkipListOfExpressions();  // read annotations.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFlags:
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kNameIndex:
       name_index_ = helper_->ReadStringReference();  // read name index.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kType:
       helper_->SkipDartType();  // read type.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kInitializer:
       if (helper_->ReadTag() == kSomething)
         helper_->SkipExpression();  // read initializer.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -156,28 +175,35 @@ void FieldHelper::ReadUntilExcluding(Field field,
       ASSERT(tag == kField);
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSourceUriIndex:
       source_uri_index_ = helper_->ReadUInt();  // read source_uri_index.
       helper_->set_current_script_id(source_uri_index_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kPosition:
       position_ = helper_->ReadPosition(false);  // read position.
       helper_->RecordTokenPosition(position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEndPosition:
       end_position_ = helper_->ReadPosition(false);  // read end position.
       helper_->RecordTokenPosition(end_position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFlags:
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kName:
       helper_->SkipName();  // read name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations: {
       annotation_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < annotation_count_; ++i) {
@@ -185,9 +211,11 @@ void FieldHelper::ReadUntilExcluding(Field field,
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kType:
       helper_->SkipDartType();  // read type.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kInitializer:
       if (helper_->ReadTag() == kSomething) {
         if (detect_function_literal_initializer &&
@@ -207,6 +235,7 @@ void FieldHelper::ReadUntilExcluding(Field field,
         helper_->SkipExpression();  // read initializer.
       }
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -222,31 +251,39 @@ void ProcedureHelper::ReadUntilExcluding(Field field) {
       ASSERT(tag == kProcedure);
       if (++next_read_ == field) return;
     }
+    /* Falls through */
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSourceUriIndex:
       source_uri_index_ = helper_->ReadUInt();  // read source_uri_index.
       helper_->set_current_script_id(source_uri_index_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kPosition:
       position_ = helper_->ReadPosition(false);  // read position.
       helper_->RecordTokenPosition(position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEndPosition:
       end_position_ = helper_->ReadPosition(false);  // read end position.
       helper_->RecordTokenPosition(end_position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kKind:
       kind_ = static_cast<Kind>(helper_->ReadByte());
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFlags:
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kName:
       helper_->SkipName();  // read name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations: {
       annotation_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < annotation_count_; ++i) {
@@ -254,20 +291,24 @@ void ProcedureHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kForwardingStubSuperTarget:
       if (helper_->ReadTag() == kSomething) {
         forwarding_stub_super_target_ = helper_->ReadCanonicalNameReference();
       }
       if (++next_read_ == field) return;
+      /* Falls through */
     case kForwardingStubInterfaceTarget:
       if (helper_->ReadTag() == kSomething) {
         helper_->ReadCanonicalNameReference();
       }
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFunction:
       if (helper_->ReadTag() == kSomething)
         helper_->SkipFunctionNode();  // read function node.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -283,28 +324,35 @@ void ConstructorHelper::ReadUntilExcluding(Field field) {
       ASSERT(tag == kConstructor);
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSourceUriIndex:
       source_uri_index_ = helper_->ReadUInt();  // read source_uri_index.
       helper_->set_current_script_id(source_uri_index_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kPosition:
       position_ = helper_->ReadPosition();  // read position.
       helper_->RecordTokenPosition(position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEndPosition:
       end_position_ = helper_->ReadPosition();  // read end position.
       helper_->RecordTokenPosition(end_position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFlags:
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kName:
       helper_->SkipName();  // read name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations: {
       annotation_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < annotation_count_; ++i) {
@@ -312,9 +360,11 @@ void ConstructorHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kFunction:
       helper_->SkipFunctionNode();  // read function.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kInitializers: {
       intptr_t list_length =
           helper_->ReadListLength();  // read initializers list length.
@@ -323,6 +373,7 @@ void ConstructorHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -338,28 +389,35 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       ASSERT(tag == kClass);
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSourceUriIndex:
       source_uri_index_ = helper_->ReadUInt();  // read source_uri_index.
       helper_->set_current_script_id(source_uri_index_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kPosition:
       position_ = helper_->ReadPosition(false);  // read position.
       helper_->RecordTokenPosition(position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEndPosition:
       end_position_ = helper_->ReadPosition();  // read end position.
       helper_->RecordTokenPosition(end_position_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFlags:
       flags_ = helper_->ReadFlags();  // read flags.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kNameIndex:
       name_index_ = helper_->ReadStringReference();  // read name index.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations: {
       annotation_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < annotation_count_; ++i) {
@@ -367,9 +425,11 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kTypeParameters:
       helper_->SkipTypeParametersList();  // read type parameters.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSuperClass: {
       Tag type_tag = helper_->ReadTag();  // read super class type (part 1).
       if (type_tag == kSomething) {
@@ -377,6 +437,7 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kMixinType: {
       Tag type_tag = helper_->ReadTag();  // read mixin type (part 1).
       if (type_tag == kSomething) {
@@ -384,9 +445,11 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kImplementedClasses:
       helper_->SkipListOfDartTypes();  // read implemented_classes.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kFields: {
       intptr_t list_length =
           helper_->ReadListLength();  // read fields list length.
@@ -396,6 +459,7 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kConstructors: {
       intptr_t list_length =
           helper_->ReadListLength();  // read constructors list length.
@@ -406,6 +470,7 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kProcedures: {
       procedure_count_ = helper_->ReadListLength();  // read procedures #.
       for (intptr_t i = 0; i < procedure_count_; i++) {
@@ -415,6 +480,7 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kClassIndex:
       // Read class index.
       for (intptr_t i = 0; i < procedure_count_; ++i) {
@@ -423,6 +489,7 @@ void ClassHelper::ReadUntilExcluding(Field field) {
       helper_->reader_.ReadUInt32();
       helper_->reader_.ReadUInt32();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -437,20 +504,25 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kName:
       name_index_ = helper_->ReadStringReference();  // read name index.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kSourceUriIndex:
       source_uri_index_ = helper_->ReadUInt();  // read source_uri_index.
       helper_->set_current_script_id(source_uri_index_);
       if (++next_read_ == field) return;
+      /* Falls through */
     case kAnnotations:
       helper_->SkipListOfExpressions();  // read annotations.
       if (++next_read_ == field) return;
+      /* Falls through */
     case kDependencies: {
       intptr_t dependency_count = helper_->ReadUInt();  // read list length.
       for (intptr_t i = 0; i < dependency_count; ++i) {
@@ -458,6 +530,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kAdditionalExports: {
       intptr_t name_count = helper_->ReadUInt();
       for (intptr_t i = 0; i < name_count; ++i) {
@@ -465,6 +538,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kParts: {
       intptr_t part_count = helper_->ReadUInt();  // read list length.
       for (intptr_t i = 0; i < part_count; ++i) {
@@ -472,6 +546,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kTypedefs: {
       intptr_t typedef_count = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < typedef_count; i++) {
@@ -479,6 +554,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kClasses: {
       class_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < class_count_; ++i) {
@@ -487,6 +563,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kToplevelField: {
       intptr_t field_count = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < field_count; ++i) {
@@ -495,6 +572,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kToplevelProcedures: {
       procedure_count_ = helper_->ReadListLength();  // read list length.
       for (intptr_t i = 0; i < procedure_count_; ++i) {
@@ -503,6 +581,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kLibraryIndex:
       // Read library index.
       for (intptr_t i = 0; i < class_count_; ++i) {
@@ -516,6 +595,7 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
       helper_->reader_.ReadUInt32();
       helper_->reader_.ReadUInt32();
       if (++next_read_ == field) return;
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -530,22 +610,27 @@ void LibraryDependencyHelper::ReadUntilExcluding(Field field) {
       helper_->ReadPosition();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kFlags: {
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kAnnotations: {
       helper_->SkipListOfExpressions();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kTargetLibrary: {
       target_library_canonical_name_ = helper_->ReadCanonicalNameReference();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kName: {
       name_index_ = helper_->ReadStringReference();
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kCombinators: {
       intptr_t count = helper_->ReadListLength();
       for (intptr_t i = 0; i < count; ++i) {
@@ -556,6 +641,7 @@ void LibraryDependencyHelper::ReadUntilExcluding(Field field) {
       }
       if (++next_read_ == field) return;
     }
+      /* Falls through */
     case kEnd:
       return;
   }
@@ -5779,7 +5865,7 @@ FlowGraph* StreamingFlowGraphBuilder::BuildGraph(intptr_t kernel_offset) {
         return BuildGraphOfImplicitClosureFunction(function);
       }
     }
-    // fallthrough intended
+    /* Falls through */
     case RawFunction::kClosureFunction:
     case RawFunction::kConvertedClosureFunction: {
       ReadUntilFunctionNode(parsed_function());  // read until function node.
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index 17eadb09ad9..31437e41285 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -3268,9 +3268,9 @@ TEST_CASE(StackTraceFormat) {
 
   const char* lib_url =
       isolate->use_dart_frontend() ? "file:///test-lib" : "test-lib";
-  const size_t kExpectedLen = 512;
-  char expected[kExpectedLen];
-  snprintf(expected, kExpectedLen,
+  const size_t kBufferSize = 1024;
+  char expected[kBufferSize];
+  snprintf(expected, kBufferSize,
            "Unhandled exception:\n"
            "MyException\n"
            "#0      baz (%1$s:2:3)\n"
diff --git a/runtime/vm/os.h b/runtime/vm/os.h
index 1fde4dac950..94bb98d194c 100644
--- a/runtime/vm/os.h
+++ b/runtime/vm/os.h
@@ -120,9 +120,9 @@ class OS {
   // Shut down the OS class.
   static void Shutdown();
 
-  static void Abort();
+  static DART_NORETURN void Abort();
 
-  static void Exit(int code);
+  static DART_NORETURN void Exit(int code);
 };
 
 }  // namespace dart
diff --git a/runtime/vm/regexp_parser.cc b/runtime/vm/regexp_parser.cc
index 5d10d0872ed..bd6b1e3b730 100644
--- a/runtime/vm/regexp_parser.cc
+++ b/runtime/vm/regexp_parser.cc
@@ -557,8 +557,8 @@ RegExpTree* RegExpParser::ParseDisjunction() {
           ReportError("Nothing to repeat");
           UNREACHABLE();
         }
-        // fallthrough
       }
+      /* Falls through */
       default:
         builder->AddCharacter(current());
         Advance();