The LastAdded points to the descriptor that was last added to the array. From the descriptor we can deduce the NextEnumerationIndex. This allows us to quickly find the property that we are transitioning to, which is necessary for transition-intensive code, eg JSON parsing.
Review URL: https://chromiumcodereview.appspot.com/10695120
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12042 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Specifically:
- In parser, check that all exports are defined.
- Move JSModule allocation from parser to scope resolution.
- Move JSModule linking from full codegen to scope resolution.
- Implement module accessors for exported value members.
- Allocate module contexts statically along with JSModules
(to allow static linking), but chain them when module literal is evaluated.
- Make module contexts' extension slot refer to resp. JSModule
(makes modules' ScopeInfo accessible from context).
- Some other tweaks to context handling in general.
- Make any code containing module literals (and thus embedding
static references to JSModules) non-cacheable.
This enables accessing module instance objects as expected.
Import declarations are a separate feature and do not work yet.
R=mstarzinger@chromium.org
BUG=v8:1569
TEST=
Review URL: https://chromiumcodereview.appspot.com/10690043
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12010 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In this design maps contain descriptor arrays, which in turn can contain transition arrays. If transitions are needed when no descriptor array is present, a descriptor array without real descriptors is inserted just so it can point at the transition array.
The transition array does not contain details about the field it transitions to. In order to weed out transitions to FIELDs from CONSTANT_FUNCTION (what used to be MAP_TRANSITION vs CONSTANT_TRANSITION), the transition needs to be followed and the details need to be looked up in the target map. CALLBACKS transitions are still easy to recognize since the transition targets are stored as an AccessorPair containing the maps, rather than the maps directly.
Currently AccessorPairs containing a transition and an accessor are shared between the descriptor array and the transition array. This simplifies lookup since we only have to look in one of both arrays. This will change in subsequent revisions, when descriptor arrays will become shared between multiple maps, since transitions cannot be shared.
Review URL: https://chromiumcodereview.appspot.com/10697015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11994 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of overwriting non-live transitions with NULL_DESCRIPTORs, we remove them from the array by compacting the array (shifting live values to the left) and in-place trimming the array. If the final descriptor array contains no live values (only contained transitions which are now all cleared), we move bit_field3 back from the descriptor array to the map. The descriptor array itself will be collected in the next GC.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10575032
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This changes the compiler to be more aggressive about lazy compilation
of closures with non-trivial outer context. Compilation can only be
triggered with a valid outer context now. One exception is the debugger,
which can request compilation of arbitrary shared code, but it ensures
to trigger compilation only at points where no context is needed.
This relands r11782, r11783, r11790 and a minor fix.
R=ulan@chromium.org
TEST=mjsunit/debug-script-breakpoints-nested
Review URL: https://chromiumcodereview.appspot.com/10543141
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11866 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Fixed invalid memory access when reading enum-cache from descriptor array with elements transitions but 0 real descriptors.
- Fixed infinite recursion in the intrusive map iterator when visiting elements transitions.
- Properly cached non-fastmode elements transitions.
Review URL: https://chromiumcodereview.appspot.com/10565030
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11841 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This changes the compiler to be more aggressive about lazy compilation
of closures with non-trivial outer context. Compilation can only be
triggered with a valid outer context now. One exception is the debugger,
which can request compilation of arbitrary shared code, but it ensures
to trigger compilation only at points where no context is needed.
R=ulan@chromium.org
TEST=mjsunit/debug-script-breakpoints-nested
Review URL: https://chromiumcodereview.appspot.com/10538102
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11782 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Removes 6 out of 8 of our remaining unintentional failures on test262.
Also fixes treatment of inherited setters added after the fact.
Specifically:
- In the runtime, when looking for setter callbacks in the prototype chain,
also look for read-only properties. If one is found, reject (exception in
strict mode). If a proxy is found, invoke proper trap.
Note: this folds in the CanPut function from the spec and avoids an extra
lookup over the prototype chain.
- In generated code for stores, insert a test for the maps from the prototype
chain, but only up to the object where the property already exists (which
may be the object itself).
In Hydrogen, if the found property is read-only or not cacheable (e.g. a
proxy), bail out; in a stub, generate an unconditional miss (to get an
exception in strict mode).
- Add test cases and adapt existing test expectations.
R=mstarzinger@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10388047
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11694 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is basically r11496, with the following changes:
* Set back pointers in maps (cherry-picked from r11528)
* Fixed size calculation in CopyInsert, as proposed by mstarzinger/rossberg
* DefineFastAccessor uses GetCallbackObject instead of GetValue (for __proto__)
* Put the code under a new flag, which is disabled by default
* Cut down the corresponding regression test
* Adapted bootup memory test, we actually only need a bit more memory on 64bit without snapshots, which can easily explained by more live maps lying around. Note that the snapshot variants are back to their previous limits.
Next steps: Investigate any performance degradationswith the flag enabled, and finally remove the flag when things are OK. Furthermore, GetCallbackObject should be merged into GetValue, the distinction is confusing and error-prone.
Review URL: https://chromiumcodereview.appspot.com/10445009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11651 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This makes back pointers in the map transition tree explicit by having
accurate back pointers throughout the lifetime of maps instead of
establishing and destroying back pointers before and after each marking
phase. This is a prerequisite for being able to clear map transitions
during incremental marking.
R=vegorov@chromium.org
BUG=v8:1465
Review URL: https://chromiumcodereview.appspot.com/10381053
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11528 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
AccessorPairs can now contain map transitions, which is similar to our current
handling of CONSTANT_FUNCTION/CONSTANT_TRANSITION, but generalized to a pair for
holding info about the getter and the setter. This way we can achieve map
sharing for objects with accessor properties, which is a prerequisite for making
them fast via inlining. We fall back to the previous way of handling accessor
properties when sharing is not possible or we don't handle a special case.
Note: When an exisiting accessor property is redefined we could in principle
move the AccessorPair out of the descriptor into the object itself (again just
like the way we do something similar for CONSTANT_FUNCTION/CONSTANT_TRANSITION),
but this would require a new property kind for holding a pair of values. Perhaps
we can implement this later, but for now this hopefully rare case is handled
like before, losing map sharing and potentially creating more maps than strictly
necessary.
Review URL: https://chromiumcodereview.appspot.com/10238005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11496 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
