Since symbols and strings share a common representation, most of this change is about consistently replacing 'String' with 'Name' in all places where property names are expected. In particular, no new logic at all is necessary for maps, property dictionaries, or transitions. :) The only places where an actual case distinction is needed have to do with generated type checks, and with conversions of names to strings (especially in logger and profiler).
Left in some TODOs wrt to the API: interceptors and native getters don't accept symbols as property names yet, because that would require extending the external v8.h.
(Baseline CL: https://codereview.chromium.org/12296026/)
R=verwaest@chromium.org,mstarzinger@chromium.org
BUG=v8:2158
Review URL: https://codereview.chromium.org/12330012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13811 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Add --harmony-symbols flag.
- Add Symbol constructor; allow symbols as (unreplaced) return value from constructors.
- Introduce %CreateSymbol and %_IsSymbol natives and respective instructions.
- Extend 'typeof' code generation to handle symbols.
- Extend CompareIC with a UNIQUE_NAMES state that (uniformly) handles internalized strings and symbols.
- Property lookup delegates to SymbolDelegate object for symbols, which only carries the toString method.
- Extend Object.prototype.toString to recognise symbols.
Per the current draft spec, symbols are actually pseudo objects that are frozen with a null prototype and only one property (toString). For simplicity, we do not treat them as proper objects for now, although typeof will return "object". Only property access works as if they were (frozen) objects (via the internal delegate object).
(Baseline CL: https://codereview.chromium.org/12223071/)
R=mstarzinger@chromium.org
BUG=v8:2158
Review URL: https://codereview.chromium.org/12296026
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13786 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
in preparation of the introduction of ES6 'symbols' (aka private/unique names).
The SymbolTable became the StringTable. I also made sure to adapt all comments. The only remaining use of the term "symbol" (other than unrelated uses in the parser and such) is now 'NewSymbol' in the API and the 'V8.KeyedLoadGenericSymbol' counter, changing which might break embedders.
The one functional change in this CL is that I removed the former 'empty_string' constant, since it is redundant given the 'empty_symbol' constant that we also had (and both were used inconsistently).
R=yangguo@chromium.org
BUG=
Review URL: https://codereview.chromium.org/12210083
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13781 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This fixes the deoptimizer to materialize arguments objects of correct
length even in cases where the actual argument values are unknown and
were optimized away by Crankshaft. This can happen if only the length
property or the identity of an arguments object is used.
R=svenpanne@chromium.org
BUG=chromium:163530
TEST=mjsunit/regress/regress-crbug-163530
Review URL: https://codereview.chromium.org/12335132
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13763 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This moves the __proto__ property to Object.prototype and turns it into
a callback property actually present in the descriptor array as opposed
to a hack in the properties lookup. For now it still is a "magic" data
property using foreign callbacks and not an accessor property visible to
JavaScript.
The second effect of this change is that JSON.parse() no longer treats
the __proto__ property specially, it will be defined as any other data
property. Note that object literals still have their special handling.
R=rossberg@chromium.org
BUG=v8:621,v8:1949,v8:2441
TEST=mjsunit,cctest,test262
Review URL: https://codereview.chromium.org/12212011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13728 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Unified parameter order of CreateHandle with the rest of v8 on the way. A few
Isolate::Current()s had to be introduced, which is not nice, and not every place
will win a beauty contest, but we can clean this up later easily in smaller steps.
Review URL: https://codereview.chromium.org/12300018
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13717 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
transitioned from a map with a different descriptor array (or has no back
pointer), mark all valid descriptors from the start.
This fixes the following memory leak: Map A shares a descriptor array
with map B. Map B adds constant function c that in its scope holds on to
an instance of B. If the descriptor array of A would keep all the shared
descriptors alive, including c, this keeps alive both A and c
indefinitely.
This CL also fixes a bug in descriptor array trimming. When trimming
descriptor arrays we need to trim off the slack as well (thus the entire
storage); and since we are trimming a descriptor array, we need to trim
* kDescriptorSize.
Review URL: https://chromiumcodereview.appspot.com/12084066
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13566 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When a data property has its attributes changed but its value remains the same,
don't emit an oldValue. This makes the API more consistent by only emitting
oldValue when the value of a property has actually changed (or been removed,
in the case of a reconfiguration as an accessor property or a deletion).
Review URL: https://codereview.chromium.org/11820004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13565 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The basic idea is to tag OOM-Failure objects with an ID indicating where they were created. This requires changes to equality comparisons.
Note to MIPS folks: I'm planning to revert this CL in a couple of days, so feel free to skip porting the platform-specific changes.
BUG=chromium:156010
Review URL: https://codereview.chromium.org/11818023
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13341 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
