Return correct ActivationFrameAlignment for iOS simulator variants

runtime/vm/os_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "vm/os.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 131 matching lines @@
 
 
 intptr_t OS::ActivationFrameAlignment() {
 #if TARGET_OS_IOS
 #if TARGET_ARCH_ARM
   // Even if we generate code that maintains a stronger alignment, we cannot
   // assert the stronger stack alignment because C++ code will not maintain it.
   return 8;
 #elif TARGET_ARCH_ARM64
   return 16;
+#else

[rmacnak, 2015/11/03 21:13:00]

Let's avoid fall through.

#elif TARGET_ARCH_IA32
  return 16;  // iOS simulator
#elif TARGET_ARCH_X64
  return 16;  // iOS simulator
#else
#error Unimplemented

+  // If the target is iOS but arch not one of ARM or ARM64, this is a simulator
+  // build
+  return 16;
 #endif
 #else  // TARGET_OS_IOS
   // OS X activation frames must be 16 byte-aligned; see "Mac OS X ABI
   // Function Call Guide".
   return 16;
 #endif  // TARGET_OS_IOS
 }
 
 
 intptr_t OS::PreferredCodeAlignment() {
@@ skipping 201 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)