Refactoring only: Make the handling of PropertyType more explicit.

src/v8globals.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_V8GLOBALS_H_
 #define V8_V8GLOBALS_H_
 
 #include "globals.h"
+#include "checks.h"
 
 namespace v8 {
 namespace internal {
 
 // This file contains constants and global declarations related to the
 // V8 system.
 
 // Mask for the sign bit in a smi.
 const intptr_t kSmiSignMask = kIntptrSignBit;
 
@@ skipping 298 matching lines @@
   NULL_DESCRIPTOR           = 9,  // only in fast mode
   // All properties before MAP_TRANSITION are real.
   FIRST_PHANTOM_PROPERTY_TYPE = MAP_TRANSITION,
   // There are no IC stubs for NULL_DESCRIPTORS. Therefore,
   // NULL_DESCRIPTOR can be used as the type flag for IC stubs for
   // nonexistent properties.
   NONEXISTENT = NULL_DESCRIPTOR
 };
 
 
+inline bool IsTransitionType(PropertyType type) {

[Kevin Millikin (Chromium), 2011/11/07 14:13:39]

I'm a bit nervous about this.  I honestly don't know if compilers do a good job
of inlining the switch.  I wonder if it's best just to put this in property.cc
(and then you don't need checks.h in this header)?

I'm also nervous about the near-circularity of putting checks.h into
v8globals.h.  v8.h contains the headers that need a fixed include order for one
reason or another, and it has v8globals.h followed by v8checks.h (which includes
checks.h).

So, not exactly a circularity but already getting tangled.

[Sven Panne, 2011/11/08 07:36:10]

I'm looking into this, but this is a bit unrelated to the other changes, so I'll
tackle this in another patch to the CL to make the review easier.

+  switch (type) {
+    case MAP_TRANSITION:
+    case CONSTANT_TRANSITION:
+    case ELEMENTS_TRANSITION:
+      return true;
+    case NORMAL:
+    case FIELD:
+    case CONSTANT_FUNCTION:
+    case CALLBACKS:
+    case HANDLER:
+    case INTERCEPTOR:
+    case NULL_DESCRIPTOR:
+      return false;
+  }
+  UNREACHABLE();  // keep the compiler happy
+  return false;
+}
+
 // Whether to remove map transitions and constant transitions from a
 // DescriptorArray.
 enum TransitionFlag {
   REMOVE_TRANSITIONS,
   KEEP_TRANSITIONS
 };
 
 
 // Union used for fast testing of specific double values.
 union DoubleRepresentation {
@@ skipping 228 matching lines @@
 
 enum ClearExceptionFlag {
   KEEP_EXCEPTION,
   CLEAR_EXCEPTION
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8GLOBALS_H_