v8/src/objects-visiting.cc
rossberg@chromium.org 764e1a0fcf ES6 symbols: Introduce Symbol class, along with abstract Name class
The new instance type 'Symbol' represents ES6 symbols (a.k.a. private/unique names). Currently, symbols are simple data objects that only carry a hash code, random-generated upon allocation.

The new type 'Name' now serves as the common super class for strings and symbols, and is supposed to represent property names. We will eventually migrate APIs from String to Name for the standard key type.

Strings and symbols share the same hash field representation, via the Name class. This way, we should be able to use the same code paths for symbols and internalized strings in most cases. Also, Symbol's instance type code is allocated adjacent to internalized string codes in the enum, allowing a simple range check for the common case.

Baseline CL: https://codereview.chromium.org/12210083/

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/12223071

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-01 10:34:31 +00:00

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// 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// 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.
#include "v8.h"
#include "ic-inl.h"
#include "objects-visiting.h"
namespace v8 {
namespace internal {
static inline bool IsShortcutCandidate(int type) {
return ((type & kShortcutTypeMask) == kShortcutTypeTag);
}
StaticVisitorBase::VisitorId StaticVisitorBase::GetVisitorId(
int instance_type,
int instance_size) {
if (instance_type < FIRST_NONSTRING_TYPE) {
switch (instance_type & kStringRepresentationMask) {
case kSeqStringTag:
if ((instance_type & kStringEncodingMask) == kOneByteStringTag) {
return kVisitSeqOneByteString;
} else {
return kVisitSeqTwoByteString;
}
case kConsStringTag:
if (IsShortcutCandidate(instance_type)) {
return kVisitShortcutCandidate;
} else {
return kVisitConsString;
}
case kSlicedStringTag:
return kVisitSlicedString;
case kExternalStringTag:
return GetVisitorIdForSize(kVisitDataObject,
kVisitDataObjectGeneric,
instance_size);
}
UNREACHABLE();
}
switch (instance_type) {
case BYTE_ARRAY_TYPE:
return kVisitByteArray;
case FREE_SPACE_TYPE:
return kVisitFreeSpace;
case FIXED_ARRAY_TYPE:
return kVisitFixedArray;
case FIXED_DOUBLE_ARRAY_TYPE:
return kVisitFixedDoubleArray;
case ODDBALL_TYPE:
return kVisitOddball;
case MAP_TYPE:
return kVisitMap;
case CODE_TYPE:
return kVisitCode;
case JS_GLOBAL_PROPERTY_CELL_TYPE:
return kVisitPropertyCell;
case JS_SET_TYPE:
return GetVisitorIdForSize(kVisitStruct,
kVisitStructGeneric,
JSSet::kSize);
case JS_MAP_TYPE:
return GetVisitorIdForSize(kVisitStruct,
kVisitStructGeneric,
JSMap::kSize);
case JS_WEAK_MAP_TYPE:
return kVisitJSWeakMap;
case JS_REGEXP_TYPE:
return kVisitJSRegExp;
case SHARED_FUNCTION_INFO_TYPE:
return kVisitSharedFunctionInfo;
case JS_PROXY_TYPE:
return GetVisitorIdForSize(kVisitStruct,
kVisitStructGeneric,
JSProxy::kSize);
case JS_FUNCTION_PROXY_TYPE:
return GetVisitorIdForSize(kVisitStruct,
kVisitStructGeneric,
JSFunctionProxy::kSize);
case FOREIGN_TYPE:
return GetVisitorIdForSize(kVisitDataObject,
kVisitDataObjectGeneric,
Foreign::kSize);
case SYMBOL_TYPE:
return GetVisitorIdForSize(kVisitDataObject,
kVisitDataObjectGeneric,
Symbol::kSize);
case FILLER_TYPE:
return kVisitDataObjectGeneric;
case JS_OBJECT_TYPE:
case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
case JS_MODULE_TYPE:
case JS_VALUE_TYPE:
case JS_DATE_TYPE:
case JS_ARRAY_TYPE:
case JS_GLOBAL_PROXY_TYPE:
case JS_GLOBAL_OBJECT_TYPE:
case JS_BUILTINS_OBJECT_TYPE:
case JS_MESSAGE_OBJECT_TYPE:
return GetVisitorIdForSize(kVisitJSObject,
kVisitJSObjectGeneric,
instance_size);
case JS_FUNCTION_TYPE:
return kVisitJSFunction;
case HEAP_NUMBER_TYPE:
case EXTERNAL_PIXEL_ARRAY_TYPE:
case EXTERNAL_BYTE_ARRAY_TYPE:
case EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE:
case EXTERNAL_SHORT_ARRAY_TYPE:
case EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE:
case EXTERNAL_INT_ARRAY_TYPE:
case EXTERNAL_UNSIGNED_INT_ARRAY_TYPE:
case EXTERNAL_FLOAT_ARRAY_TYPE:
case EXTERNAL_DOUBLE_ARRAY_TYPE:
return GetVisitorIdForSize(kVisitDataObject,
kVisitDataObjectGeneric,
instance_size);
#define MAKE_STRUCT_CASE(NAME, Name, name) \
case NAME##_TYPE:
STRUCT_LIST(MAKE_STRUCT_CASE)
#undef MAKE_STRUCT_CASE
return GetVisitorIdForSize(kVisitStruct,
kVisitStructGeneric,
instance_size);
default:
UNREACHABLE();
return kVisitorIdCount;
}
}
} } // namespace v8::internal