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
We use foreign callbacks to make some properties shadow internal values
but still behave as data properties from within JavaScript. This means
when a value is passed to Object.defineProperty() on such a property,
it should update the internal value instead of redefinind the property
and destroying the shadowing.
R=rossberg@chromium.org
BUG=v8:1530
TEST=mjsunit/regress/regress-1530,test262/S15.3.3.1_A4
Review URL: http://codereview.chromium.org/8996008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10279 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
source code positions it gets from the program counter to recreate the scope
chain by reparsing the function or program.
This CL includes the following changes
* Adds source code positions for the assignment added by the rewriter.
* Run the preparser over global code first.
* Use the ScopeType from the ScopeInfo to determine if the code being debugged
is eval, function or global code instead of looking up the '.result' symbol.
TEST=mjsunit/debug-stepout-scope.js
Review URL: http://codereview.chromium.org/8590027
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10076 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
So far free variables references in eval code are not statically
resolved. For example in
function foo() { var x = 1; eval("y = x"); }
the variable x will get mode DYNAMIC and y will get mode DYNAMIC_GLOBAL,
i.e. free variable references trigger dynamic lookups with a fast case
handling for global variables.
The CL introduces static resolution of free variables references in eval
code. If possible variable references are resolved to bindings belonging to
outer scopes of the eval call site.
This is achieved by deserializing the outer scope chain using
Scope::DeserializeScopeChain prior to parsing the eval code similar to lazy
parsing of functions. The existing code for variable resolution is used,
however resolution starts at the first outer unresolved scope instead of
always starting at the root of the scope tree.
This is a prerequisite for statically checking validity of assignments in
the extended code as specified by the current ES.next draft which will be
introduced by a subsequent CL. More specifically section 11.13 of revision 4
of the ES.next draft 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.
TEST=existing tests in mjsunit
Review URL: http://codereview.chromium.org/8508052
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9999 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Do not rely on 'default' clauses or 'if's when analysing a PropertyType, because
this makes it hard to find the relevant places when a new type is added. Note
that the detection of "phantom property types" is left untouched, because this
might have a performance impact, especially for the GC (to be investigated).
This is a preliminary step for introducing a new kind of map transition.
Review URL: http://codereview.chromium.org/8491016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9900 ce2b1a6d-e550-0410-aec6-3dcde31c8c00