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
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
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
Constructs the (generally cyclic) graph of module instance objects
and populates their exports. Any exports other than nested modules
are currently set to 'undefined' (but already present as properties).
Details:
- Added new type JSModule for instance objects: a JSObject carrying a context.
- Statically allocate instance objects for all module literals (in parser 8-}).
- Extend interfaces to record and unify concrete instance objects,
and to support iteration over members.
- Introduce new runtime function for pushing module contexts.
- Generate code for allocating, initializing, and setting module contexts,
and for populating instance objects from module literals.
Currently, all non-module exports are still initialized with 'undefined'.
- Module aliases are resolved statically, so no special code is required.
- Make sure that code containing module constructs is never optimized
(macrofy AST node construction flag setting while we're at it).
- Add test case checking linkage.
Baseline: http://codereview.chromium.org/9722043/R=svenpanne@chromium.org,mstarzinger@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/9844002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11336 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is a preparatory step for using the HashMap clas with Literal keys in the
full code generator. It removes some duplicated code already and removes the
need for 2 HashMaps at each use, which was overly complicated.
Removed one dead function on the way.
Review URL: https://chromiumcodereview.appspot.com/9639011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10973 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
All module expressions, and all variables that might refer to modules,
are assigned interfaces (module types) that are resolved using
unification. This is necessary to deal with the highly recursive
nature of ES6 modules, which does not allow any kind of bottom-up
strategy for resolving module names and paths.
Error messages are rudimental right now. Probably need to track
more information to make them nicer.
R=svenpanne@chromium.org
BUG=v8:1569
TEST=
Review URL: https://chromiumcodereview.appspot.com/9615009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10966 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Main change from the original CL: Call::ComputeTarget does not use IsProperty
anymore, because this would potentially need a holder, which we don't have
here. Using Map::LookupInDescriptors with a NULL holder is a bit fishy in
general, because one has to be *extremely* careful when using its LookupResult.
The original CL made Chrome's NetInternalsTest.netInternalsTourTabs browser test
fail, but it's a mystery how this could happen: We should never reach
Call::ComputeTarget via Call::RecordTypeFeedback with a CALLBACKS property,
because we never consider calls to them monomorphic, which is in turn because of
the stub cache leaving them in the pre-monomorphic state. Therefore, I don't
have a clue how to write a regression test for this...
As an additional tiny bonus, the --trace-opt output for deoptimizations has been
improved.
Review URL: https://chromiumcodereview.appspot.com/9584003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10906 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The old HashMap class had an explicit member to determine the allocation
policy. The template version matches the approach used already for
lists.
Cleanup some include dependencies and unnecessary forward declarations.
Cleanup some dead code from isolate.h and replace some HEAP macros
with GetHeap().
Review URL: https://chromiumcodereview.appspot.com/9372106
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
With the upcoming changes to CALLBACKS properties, a predicate on the transition
type alone doesn't make sense anymore: For CALLBACKS one has to look into the
property's value to decide, and there is even the possibility of having a an
accessor function *and* a transition in the same property.
I am not completely happy with some parts of this CL, because they contain
redundant code, but given the various representations we currently have for
property type/value pairs, I can see no easy way around that. Perhaps one can
improve this a bit in a different CL, the current diversity really, really hurts
productivity...
As a bonus, this CL includes a few minor things:
* CaseClause::RecordTypeFeedback has been cleaned up and it handles the
NULL_DESCRIPTOR case correctly now. Under some (very unlikely) circumstances,
we previously missed some opportunities for monomorphic calls. In general, it
is rather unfortunate that NULL_DESCRIPTOR "shines through", it is just a
hack for the inability to remove a descriptor entry during GC, something
callers shouldn't have to be aware of.
* DescriptorArray::CopyInsert has been cleaned up a bit, preparing it for later
CALLBACKS-related changes.
* LookupResult::Print is now more informative for CONSTANT_TRANSITION.
Review URL: https://chromiumcodereview.appspot.com/9320066
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10600 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Yak shaving for map sharing with accessor properties contd.: When CALLBACKS can
have map transitions, simply looking at the property type is not sufficient
anymore to decide if a property is there or not. One has to look at the actual
contents of the descriptor entry then, but this breaks down sometimes when the
lookup is being done with a NULL holder. Luckily enough, we can oftren replace
IsProperty by the simpler IsFound, because we inspect the type immediately
afterwards, anyway.
Review URL: https://chromiumcodereview.appspot.com/9280007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The ES.next draft rev 4 in section 11.13 reads:
It is a Syntax Error if the AssignmentExpression is contained in extended code
and the LeftHandSideExpression is an Identifier that does not statically resolve
to a declarative environment record binding or if the resolved binding is an
immutable binding.
This CL adds corresponding static checks for the immutable binding case.
TEST=mjsunit/harmony/block-const-assign
Review URL: http://codereview.chromium.org/8688007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10156 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL introduces a third mode next to the non-strict
(henceforth called 'classic mode') and 'strict mode'
which is called 'extended mode' as in the current
ES.next specification drafts. The extended mode is based on
the 'strict mode' and adds new functionality to it. This
means that most of the semantics of these two modes
coincide.
The 'extended mode' is entered instead of the 'strict mode'
during parsing when using the 'strict mode' directive
"use strict" and when the the harmony-scoping flag is
active. This should be changed once it is fully specified how the 'extended mode' is entered.
This change introduces a new 3 valued enum LanguageMode
(see globals.h) corresponding to the modes which is mostly
used by the frontend code. This includes the following
components:
* (Pre)Parser
* Compiler
* SharedFunctionInfo, Scope and ScopeInfo
* runtime functions: StoreContextSlot,
ResolvePossiblyDirectEval, InitializeVarGlobal,
DeclareGlobals
The old enum StrictModeFlag is still used in the backend
when the distinction between the 'strict mode' and the 'extended mode' does not matter. This includes:
* SetProperty runtime function, Delete builtin
* StoreIC and KeyedStoreIC
* StubCache
Review URL: http://codereview.chromium.org/8417035
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10062 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Named function expression have an implicit local variable that
refers to the current function (ThisFunction). Before we only could inline
anonymous function expressions like:
A.prototype.foo = function() {}
as opposed to
A.prototype.foo = function foo() {}
This change enables inlining function of expressions like this.
Review URL: http://codereview.chromium.org/8346032
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9699 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Although this patch is not small, most parts of it are rather mechanical:
* First of all, the concept of a 'nil-like' value is introduced, which can be
null or undefined. They are treated symmetrically regarding comparisons, so
it makes sense to handle them in a uniform manner. It is a mystery why
JavaScript defines two of those beasts, when even *one* is a design wart...
* Extended and renamed a few things which now handle undefined in addition to
null.
* Made the parts of the full code generator and the hydrogen generation which
deal with comparisons a bit more similar regarding their handling of special
cases.
* Refactored the syntactical detection of special cases for comparisons,
hopefully making them a bit more readable and less copy-n-paste-oriented.
Things like this should really be a one-liner in any sane programming
language... :-P
* Cut down the length of the argument lists of a few functions to something
less insane, making them more easily understandable locally. This involves
minor code duplication, but this was a good tradeoff and can be remedied
later if necessary.
* Replaced some boolean arguments with more readable enums.
* Fixed a TODO: Values which are definitely a Smi or unboxed can never be equal
to null or undefined.
Review URL: http://codereview.chromium.org/7918012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9323 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The Great Master Plan is to move the recognition of special cases for
comparisons further down the compilation pipeline where more information is
available. This is a first step into this direction: The special handling of
equality comparisons involving null is pushed from the parser to the code
generators, removing the need for a special AST node. (There are rumors from
usually well-informed sources that this node type is actually a relic of ancient
crankshaft days...)
The next steps will be the unification of null/undefined handling and pushing
the special case handling in crankshaft even further down the pipeline, enabling
the recognition of cases like "var foo=null; if (foo === bar) ...", but these
will be in separate CLs.
Review URL: http://codereview.chromium.org/7887037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9293 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Some AST nodes (Property, Call, etc.) store either a list of receiver
types or a monomorphic receiver type. This patch merges the two fields
using a small pointer list. GetMonomorphicReceiverType() is now a
purely convenience function returning the first and only recorded
type.
This saves about 500K (of about 39M) on average when compiling V8
benchmark as measured by a simple patch adding a zone allocation
counter (https://gist.github.com/1149397).
R=kmillikin@chromium.org
Review URL: http://codereview.chromium.org/7655017
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8993 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove the try/finally used for with and catch. Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.
And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.
BUG=
TEST=
Review URL: http://codereview.chromium.org/7618007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Detect the pattern in both, the full compiler and crankshaft and generate direct pointer
comparisons. Along the way I cleaned up 'typeof <expression> == <string literal>' comparisons
as well by lifting platform independent code and checking the symmetric case.
BUG=v8:1440
TEST=cctest/test-api.cc
Review URL: http://codereview.chromium.org/7216008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8420 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Introduce separate maps for function and with contexts. Use the function
context map for testing whether a context is a function context (global
contexts are no longer function contexts).
Split the paths for allocating with and catch contexts.
Rename some functions. Generally refactor code to make it simpler.
R=ager@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/7003058
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8231 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Only IA32 version for now. I'll start porting.
Strict mode functions are to get 'undefined' as the receiver when
called with an implicit receiver. Modes are bad! It forces us to have
checks on all function calls.
This change attempts to limit the cost by passing information about
whether or not a call is with an implicit or explicit receiver in ecx
as part of the calling convention. The cost is setting ecx on all
calls and checking ecx on entry to strict mode functions.
Implicit/explicit receiver state has to be maintained by ICs. Various
stubs have to not clobber ecx or save and restore it.
CallFunction stub needs to check if the receiver is implicit when it
doesn't know from the context.
Review URL: http://codereview.chromium.org/7039036
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8040 ce2b1a6d-e550-0410-aec6-3dcde31c8c00