(qua last week's TC39)
Specifically:
- Install Symbol constructor function on the global object.
- Adjust code generation for typeof.
- Remove IsSymbol built-in, IS_SYMBOL macro now defined using typeof.
- Remove hack that allowed symbols as constructor results, and some other special cases.
- Remove symbol_delegate and GetDelegate function.
- Extend ToBoolean stub to handle symbols.
- Extend ToNumber to return NaN on symbols.
- Poison symbol's toString function, and thereby ToString on symbols.
R=mstarzinger@chromium.org
BUG=v8:2158
Review URL: https://codereview.chromium.org/12957004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
The approach in this change is to handle the unwrapping/wrapping of the global object transparently with respect to the JS implementation of Object.observe. An alternate approach would be to add a runtime method like %IsJSGlobalProxy and %UnwrapJSGlobalProxy, but it seems ugly to give JS (even implementation JS) access to the unwrapped global.
BUG=v8:2409
Review URL: https://codereview.chromium.org/11414094
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13142 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Making the code size predictable is hard, and to make things even more
complicated, the start of a function can contain various stuff like calls to a
profiling hook, receiver adjustment or dynamic frame alignment. Instead of
tackling all these problems separately, we now simply record the offset where
patching should happen later in the Code object itself.
Review URL: https://codereview.chromium.org/11316218
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13081 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
These are likely causing some of the flaky crashes in Object.observe code. I've reorganized some of the code to minimize the number of necessary calls to map() (by saving the result of map()->is_observed() in a local bool).
Also move down an unnecessarily early call to Uint32ToString when sending an element deletion notification.
Review URL: https://chromiumcodereview.appspot.com/11316202
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13070 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Modules now have their own local scope, represented by their own context.
Module instance objects have an accessor for every export that forwards
access to the respective slot from the module's context. (Exports that are
modules themselves, however, are simple data properties.)
All modules have a _hosting_ scope/context, which (currently) is the
(innermost) enclosing global scope. To deal with recursion, nested modules
are hosted by the same scope as global ones.
For every (global or nested) module literal, the hosting context has an
internal slot that points directly to the respective module context. This
enables quick access to (statically resolved) module members by 2-dimensional
access through the hosting context. For example,
module A {
let x;
module B { let y; }
}
module C { let z; }
allocates contexts as follows:
[header| .A | .B | .C | A | C ] (global)
| | |
| | +-- [header| z ] (module)
| |
| +------- [header| y ] (module)
|
+------------ [header| x | B ] (module)
Here, .A, .B, .C are the internal slots pointing to the hosted module
contexts, whereas A, B, C hold the actual instance objects (note that every
module context also points to the respective instance object through its
extension slot in the header).
To deal with arbitrary recursion and aliases between modules,
they are created and initialized in several stages. Each stage applies to
all modules in the hosting global scope, including nested ones.
1. Allocate: for each module _literal_, allocate the module contexts and
respective instance object and wire them up. This happens in the
PushModuleContext runtime function, as generated by AllocateModules
(invoked by VisitDeclarations in the hosting scope).
2. Bind: for each module _declaration_ (i.e. literals as well as aliases),
assign the respective instance object to respective local variables. This
happens in VisitModuleDeclaration, and uses the instance objects created
in the previous stage.
For each module _literal_, this phase also constructs a module descriptor
for the next stage. This happens in VisitModuleLiteral.
3. Populate: invoke the DeclareModules runtime function to populate each
_instance_ object with accessors for it exports. This is generated by
DeclareModules (invoked by VisitDeclarations in the hosting scope again),
and uses the descriptors generated in the previous stage.
4. Initialize: execute the module bodies (and other code) in sequence. This
happens by the separate statements generated for module bodies. To reenter
the module scopes properly, the parser inserted ModuleStatements.
R=mstarzinger@chromium.org,svenpanne@chromium.org
BUG=
Review URL: https://codereview.chromium.org/11093074
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13033 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The previous implementation in Accessors::ArraySetLength failed when array length was set through StoreIC_ArrayLength. But that stub and the accessor both delegate to JSArray::SetElementsLength, so moving the code there allows notifications to be sent in both cases.
Review URL: https://codereview.chromium.org/11275292
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12962 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL has two parts: the first is the logic itself, whereby each observer callback is assigned
a "priority" number the first time it's passed as an observer to Object.observe(), and that
priority is used to determine the order of delivery.
The second part invokes the above logic as part of the API, when the JS stack winds down to
zero.
Added several tests via the API, as the delivery logic isn't testable from a JS test
(it runs after such a test would exit).
Review URL: https://codereview.chromium.org/11266011
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12902 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When code objects in the heap for FUNCTIONs and OPTIMIZED_FUNCTIONs are marked by the GC, their prologue is patched with a call to a stub that removes the patch. This allows the collector to quickly identify code objects that haven't been executed since the last full collection (they are the ones that sill contain the patch). The functionality is currently disabled, but can be activated by specifying the "--age-code".
R=mstarzinger@chromium.org
Review URL: https://codereview.chromium.org/10837037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12898 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This fixes a corner case when the instance prototype of a function is
changed while inobject slack tracking is still in progress. This caused
the intial map to be unrelated for functions with the same shared info
and hence the shared construct stub is no longer generic enough to work
for all those functions.
R=danno@chromium.org
BUG=chromium:157019
TEST=mjsunit/regress/regress-crbug-157019
Review URL: https://codereview.chromium.org/11293059
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In more detail:
- Set observation bit for observed objects (and make NormalizedMapCache respect it).
- Mutation of observed objects is always delegated from ICs to runtime.
- Introduce JS runtime function for notifying generated changes.
- Invoke this function in the appropriate places (including some local refactoring).
- Inclusion of oldValue field is not yet implemented, nor element properties.
Also, shortened flag to --harmony-observation.
R=verwaest@chromium.org
BUG=
Review URL: https://codereview.chromium.org/11347037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12867 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The delete operator always return true in case of indexed property. It
should return false if an indexed property can't be deleted (eg.
DontDelete attribute is set or a string object is the holder).
Contributed by Peter Varga <pvarga@inf.u-szeged.hu>
BUG=none
TEST=mjsunit/delete-non-configurable
Review URL: https://codereview.chromium.org/11094021
Patch from Peter Varga <pvarga@inf.u-szeged.hu>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12736 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This happens when a map A with no descriptors in fast_holey_elements
mode first gets some properties, making it share descriptor arrays with
a map B to which it transitions. Then map A transitions elements kind to
dictionary_elements in map C. C stores the empty_descriptor_array in its
own transition array. When adding a property to C, C transitions to D
and shares the descriptors. If D dies, a CNLT clears the transition
array of C, making the descriptor array of A (and thus also of B) shine
through. If a property is now added to an object in state C, it'll inherit
all the properties of A (and B). If those properties had high field indices,
we do not have a large enough backing store for the single newly added
property, and we'll write out of bounds.
BUG=chromium:151749
Review URL: https://chromiumcodereview.appspot.com/11017054
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12687 ce2b1a6d-e550-0410-aec6-3dcde31c8c00