The debugger can be entered from the deferred stack check in optimized code. This can cause both lazy deoptimization and debugger deoptimization (setting the first break point and inspecting the stack for optimized code respectively). This required deoptimization support from the deferred stack check.
The lazy deoptimiztion call is inserted when the deferred code is done including restoring the registers. The bailout to the full code is the begining of the loop body as that is where the stack check is sitting in the optimized code. The bailout is not to the stack check in the full code as that is sitting at the end of the loop.
R=kmillikin@chromium.org
BUG=none
TEST=none
Review URL: http://codereview.chromium.org//7212025
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8535 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Thread class was receiving an isolate parameter by default.
This approact violates the assumption that only VM threads
can have an associated isolate, and can lead to troubles,
because accessing the same isolate from different threads
leads to race conditions.
This was found by investigating mysterious failures of the
CPU profiler layout test on Linux Chromium. As almost all
threads were associated with some isolate, the sampler was
trying to sample them.
As a side effect, we have also fixed the DebuggerAgent test.
Thanks to Vitaly for help in fixing isolates handling!
R=vitalyr@chromium.org
BUG=none
TEST=none
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8259 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.
Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.
Code Review URL: http://codereview.chromium.org/6474026/
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6760 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.
Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.
Code Review URL: http://codereview.chromium.org/6474026/
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6756 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1. Added gdb style debugger commands (and their shortcuts) for d8.
These include:
- s[tep] : step into the current statement.
- s[tep]i[n]: step into the current statement with the minimum step.
- n[ext] : step to the next statement.
- fin[ish] : step out of the current function.
- cond : setting conditions on breakpoints.
- d[elete] : deletes breakpoints.
- en[able]|dis[able]: enables/disables breakpoints including
exception breakpoints.
- ignore : ignores a breakpoint for a specified period.
- inf[o] ar[gs] : info on arguments of the current function.
- inf[o] lo[cals] : info on local vars of the current function.
- inf[o] br[eakpoints] : info on breakpoints.
- l[ist] : similar to source, but allows the user to continually
dump subsequent lines of source code either in the
forward or backward direction.
- quit / exit / disconnect : terminates the remote debugger
session.
NOTE: Active breakpoints will automatically be disabled when
the remote debugger detaches. This allows v8 to continue to
run without worrying about a loss of a debugger session.
2. Added support for breaking the debugger by simply typing ENTER.
The break command is now optional.
3. Once the debugger is broken, the user can now just type ENTER
to repeat the last command. This is useful to functionality that
needs to be invoked repeatedly e.g. step, list.
4. Added more verbose descriptions in d8's help.
5. Fixed a line and column number offset bug in the listing of breakpoint
line and column numbers.
6. Added a gc command to allow GCs to be requested from the debugger
interface. The plumbing for requesting different types of GCs is
there, but the underlying implementation currently only triggers a
full mark-compact GC. The command also returns the before and after
sizes of the heap.
7. Added trace json, and flags commands that are not published in help.
trace json is used for tracing the debugger packets send from and
received by d8. flags is for setting v8 flags. These are useful for
people debugging v8 itself, but not necessarily users of v8.
8. Added the ability to enable and disable break on all / uncaught
exceptions in to d8.
9. Added a fix to prevent the Debugger Agent from being re-instantiated
if one already exists.
10. Added the ability to filter results of the script command by matching
text or numbers on the results.
11. Added v8 flags to enable/disable the sending of debugger BeforeCompile,
AfterCompile, and ScriptCollected events.
12. Fixed some undefined value bugs that resulted in v8 or the debugger
failing.
13. Added a few minor WEBOS__ customizations (analogous to ANDROID
customizations).
Patch by Mark Lam from Hewlett-Packard Development Company, LP
Review URL: http://codereview.chromium.org/5980006
Review URL: http://codereview.chromium.org/6086010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6200 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The live registers are now only stored to the expression stack with the non pointer values being stored as smis (on the 32-bit platforms these values are assumed to be 31-bit max).
This makes the CEntryStub entry/exit code much simpler, and there is no longer any need for a mode (debug or normal) on it.
Fix a missing live register when breaking at ARM keyed load.
Review URL: http://codereview.chromium.org/3141047
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5358 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When removing debug_info from SharedFunctionInfo, clear all breakpoints associated with that debug_info.
This is needed because function will live in heap until next gc, and therefore can be found
by Runtime::FindSharedFunctionInfoInScript.
Review URL: http://codereview.chromium.org/2848032
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4997 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This changes the way the constants kJSObjectType, kFirstNonstringType and kProxyType are made available to the inlined part of the V8 API. This change to fixed constants resolves linker this linker error Windows
error LNK2001: unresolved external symbol "public: static int v8::internal::Internals::kJSObjectType" (?kJSObjectType@Internals@internal@v8@@2HA)
when linking against a V8 DLL.
This change also makes it possible to build all the C++ tests with ENABLE_DEBUGGER_SUPPORT not defined. Now C++ tests run ENABLE_DEBUGGER_SUPPORT not defined, and only the JavaScript tests which tests the debugger fails when ENABLE_DEBUGGER_SUPPORT is not defined.
Review URL: http://codereview.chromium.org/2820016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4898 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added support for more precise break points when debugging and stepping. To achieve that additional nop instructions are inserted where breaking would otherwise be impossible. The number of nop instructions inserted are sufficient to make place for patching with a call to a debug break code stub. On Intel that is 5 nop's for 32-bit and 13 for 64-bit. Om ARM 3 nop instructions (12 bytes) are required.
In order to avoid inserting nop's in to many places a simple ast checker have been added to check whether there are breakable code in a statement or expression. If it is possible to break in an expression no additional break enabeling code is inserted.
Added break locations to the true and false part of a conditional expression.
Added stepping tests to cover more constructs.
These changes are only in the full compiler.
Changed the default value for the option --debugger in teh d8 shell from true to false. The reason for this is that with --debugger turned on the full compiler will be used for all code in when running d8, which can be unexpeceted.
Review URL: http://codereview.chromium.org/2693002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Eventually named property query callbacks will return attributes
(as an integer) or an empty handle if property is not intercepted.
To gradually migrate to this new API, USE_NEW_QUERY_CALLBACK
macro would control if old or new style API is used.
So the migration plan is:
1) introduce new API which should be explictily enabled;
2) switch to new API defining USE_NEW_QUERY_CALLBACK before
include of <v8.h> (that would require changes to client code as well)
3) remove old API from v8
4) remove #define USE_NEW_QUERY_CALLBACK from clients.
Review URL: http://codereview.chromium.org/2576003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4797 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1) Exposes Local<Context> v8::Debug::GetDebugContext().
Rationale: We can already get debugger context instance using various workarounds,
so exposing it explicitly in the API only makes things more clear.
2) Removes debugger.HasJavaScriptFrames() requirement for entering debugger context.
Rationale: Sometimes we'd like to call into debugger from the external native code.
3) Makes Debugger v8::Debug::Call execute on debugger context's global object.
Rationale: This is somewhat arguable, but temporary measure. We've agreed that we
should introduce a DebugAPI object that would expose necessary API in the debug-delay.
The problem is that it would take some time to define this API and it is not really
convenient to do that on the v8 land given the difference in v8 / host lifecycle.
The plan is to compose this API as a Debug.* wrapper outside v8 by means of exposing
debugger context's global object here, and once API settles down, upstream it to v8 and
start making Debug::Calls on this new DebugAPI object instead.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4251 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Storing a JSArray in the Script object could cause an indirect reference from the compilation cache to a global object to be created. Now the line ends are only stored as a FixedArrya and when that is needed in JavaScript a JSArray copy is created. Changed some of the JavaScript code to cache the line ends in a local variable for better performance.
BUG=http://code.google.com/p/v8/issues/detail?id=528
TEST=test/test-api/Bug528
Review URL: http://codereview.chromium.org/434117
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3374 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A callback on the debugger thread when a message is received. Allows the
embedding application to wake up the main thread in order to handle the
message. Useful when the embedding application is idle and sitting in a
select() call.
Patch by Ryan Dahl <coldredlemur@gmail.com>
Review URL: http://codereview.chromium.org/395013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3326 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In the generated code for function.apply there was a loop checking the stack limit for interruption. This loop would call into the runtime system to handle interuption and keep running until there was no interruption. However if the interuption was debug break the runtime system would never clear the interruption as debug break is prevented in builtins are prevented and the assumption here was that returning with the debug break flag set would move execution forward.
Renamed initial_jslimit and initial_climit to real_jslimit and real_climit. Renamed a few external references related to the stack limit as well.
Exposed the real stack limit to generated code to make the stack check when entering function.apply use the real stack limit and not the stack limit which is changed to signal interruption.
Added the real stack limit to the roots array.
BUG=http://code.google.com/p/v8/issues/detail?id=493
TEST=cctest/test-debug/DebugBreakFunctionApply
Review URL: http://codereview.chromium.org/345048
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3229 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
of individual changes:
- Added infrastructure for custom stub caching.
- Push the code object onto the stack in exit calls instead of a
debug/non-debug marker.
- Remove the DEBUG_EXIT frame type.
- Add a new exit stub generator for API getters.
Review URL: http://codereview.chromium.org/330017
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3130 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The main piece of this change was to add support for break on return for ARM. On ARM the normal js function return consist of the following code sequence.
mov sp, fp
ldmia sp!, {fp, lr}
add sp, sp, #4
bx lr
to a call to the debug break return entry code using the following code sequence
mov lr, pc
ldr pc, [pc, #-4]
<debug break return entry code entry point address>
bktp 0
The values of Assembler::kPatchReturnSequenceLength and Assembler::kPatchReturnSequenceLength are somewhat misleading, but they fit the current use in the debugger. Also Assembler::kPatchReturnSequenceLength is used in the IC code as well (for something which is not related to return sequences at all). I will change that in a separate changelist.
For the debugger to work also added recording of the return sequence in the relocation info and handling of source position recording when a function ends with a return statement.
Used the constant kInstrSize instead of sizeof(Instr).
Passes all debugger tests on both simulator and hardware (only release mode tested on hardware).
Review URL: http://codereview.chromium.org/199075
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2879 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Running "system" JavaScript with the debug break flag active leads to slow running code while waiting for the break in non "system" JavaScript (one exception to this it is to try to avoid breaks in the clear mirror cache JavaScript code called when leaving the debugger).
* If this happens while processing RegExp running in native code an infinite loop is created as the stack guard handler for RegExp does not move execution forward
Fixed a GC bug in the interrupt handling for RegExp running in native code.
Added test of debug break while in debug message handler callback and debug break while executing a RegExp.
Review URL: http://codereview.chromium.org/115262
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2074 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.
Review URL: http://codereview.chromium.org/115756
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Without the change the debugger may crash as Debugger::EventActive(v8::Break) called from OnDebugBreak may clear current debugger context.
Also when compilation cache was enabled debugger could fail on second attach for the same reason(see AfterCompileMessageWhenMessageHandlerIsReset).
BUG=12404
Review URL: http://codereview.chromium.org/115709
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2035 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When loaded scripts are requested this cache is filled with all the script objects in the heap. Hereafter its content is kept in sync with the active scripts in the heap through the notifications of new scripts compiled and by using weak handles to get notified when a script is collected.
Through the tracking of collected scripts the debugger event OnScriptCollected have been added to notify a debugger that a script previously returned through the scripts command is no longer in use.
Make the ComputeIntegerHash globally available.
Moved clearing of the mirror cache to when debugger is really left. Previously recursive invocations of the debugger cause the mirror cache to be cleared causing handles to become either stale or reference other objects.
Review URL: http://codereview.chromium.org/115462
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1988 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The object delivered to the debug message handler contains additional information on the current break handling the messages.
Clients which require just JSON message parsing can simply get the JSON using the GetJSON message on the message object to still have the previous behaviour.
NewMessageHangler(const v8::Debug::Message& message) {
v8::String::Value val(message.GetJSON());
OldMessageHandler(Vector<uint16_t>(const_cast<uint16_t*>(*val), val.length()));
}
Refactored some of the debugger code to use internal handles instead of API handles. Also changed Object to JSObject is some places.
The access to the active context when the break occurred is still not implemented. I will add this in a new CL, as this one is quite big already.
Review URL: http://codereview.chromium.org/99122
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1811 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The debug message thread was introduced to make it possible to have the message handler callback be called from a different thread than the thread running V8 where the debug event occoured, but it never had any practical use, and prevents providing information to the message handler which is only available from the V8 thread.
In the future any thread decoupling will have do be done by the embedder.
This also removes the queue used for outbound messages.
Renamed the class Message to CommandMessage as it is only used for debugger commands from the client. Related message queue classes has also been renamed.
Review URL: http://codereview.chromium.org/93118
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1788 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For keyed IC loads setting a break point now ensures that the inlined code is not used. When the break point is set the inlined map check is changed to fail causing the inlined code not to be used but the IC to be called. As long at the break point is set the map check will stay invalid.
Review URL: http://codereview.chromium.org/87025
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1756 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The generic step-in mechanism floods the function called with break points to ensure a break is hit when entering the function. This generic mechanism was also used for function.apply. The code for function.apply contains a keyed load IC which was patched when stepping into function.apply. However function.apply enteres an internal frame not a JavaScript frame. This caused the logic for returning from the break in function.apply to fail as it forced a jump to the IC on the top JavaScript frame. The top JavaScript frame was the frame for the function calling function.apply not the frame for the apply function. Now returning from the break point in the keyed load IC in the apply code caused a jump to the code for the call IC for the function calling function.apply in the first place. Not a pretty sight.
Step-in now handles function.apply as a separate case where the actual JavaScript function called through apply is flodded with breakpoints instead of the function.apply function.
BUG=269
BUG=8210@chromium.org
Review URL: http://codereview.chromium.org/63055
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1683 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add a semaphore for accessing debugger varaibles which can be changed from a different thread. This is mainly the debug message handler which can be set to NULL to disconnect the debugger.
Control the unloading of the debugger from the V8 thread. Before the debugger unload was called from the thread setting the debug message handler to NULL. This was not safe as this involves calling into V8. This change handles the unloading of the debugger either when entering a debugger event and the debugger was disconnected while the debugger was not active or when leaving the debugger and the debugger was disconnected while the debugger was active.
Add a flag to avoid unloading the debugger if debugger code is used by the application for other purposes than debugging.
Added tests for clearing the debug message handler.
Review URL: http://codereview.chromium.org/56102
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1648 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When the debugger agent terminates the used port can be stuck in TIME_WAIT for some time depending on the OS and the state of the socket. With this change will allow the debug agent to start listening on a port still in TIME_WAIT. During development of both V8 and embedding applications this makes it much easier to restart an application using the debugger agent.
This also makes it possible to run the tests involving the debugger agent multiple times without failure.
Review URL: http://codereview.chromium.org/50050
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1558 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
During bind and listen socket errors are now handled. If the listen socket is occoupied the agent will retry its bind operation until success or shutdown.
Added orderly shutdown of the debugger agent both with and without a client connected.
Review URL: http://codereview.chromium.org/50007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1552 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This makes it possible to remote debuggers to just add commands to the queue without having to request a break as well. As soon as any JavaScript executes the debugger commands will be processed and the response send to the remote debugger.
Currently hide this behind a flag (--debugger-auto-break) as the current command line debugger in Chrome is not designed for this new behaviour, whereas the new Chrome developer tools will use it.
Review URL: http://codereview.chromium.org/42173
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1508 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Changed the script break points to be able to handle both break points based on script names and script ids. When break points are set through a script id the position is relative to the script itself. This is different from the script break points set through script names where the line/coulmn offset is taken into account.
This has the side effect that function break points are not converted into script break points for named scripts.
Show the script id in the D8 shell debugger when listing all scripts using the 'scripts' command.
Review URL: http://codereview.chromium.org/40317
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1468 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add the ability to have the host embedding V8 receive a callback in the V8 thread while V8 is processing a debug callback. When V8 is processing a debug callback the thread where V8 is executing is sitting in a tight loop processing debug commands until the continue command has been executed. In some embedding situations it is beneficial to be able to call back into the embedding host from the thread where V8 is sitting. The might have functions which needs to be called to complement the JavaScript debugging.
Using the uint16_t array to pass a void* is a temporary hack.
Review URL: http://codereview.chromium.org/20491
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1318 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added a number of handle scopes to the debugger code to keep handles local to the function using them.
Fixed SetDebugEventListener to actually unregister when passed a NULL pointer. Previously this NULL pointer was wrapped in a Proxy.
BUG=1242702
Review URL: http://codereview.chromium.org/21347
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1269 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Changed the name of Runtime_GetPrototype to Runtime_DebugGetPrototype to indicate that it is a debugger related function and changed its implementation to do the correct __proto__ lookup.
Added some more information to the Map debug print.
Review URL: http://codereview.chromium.org/18658
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1126 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added quoting of the name of the ref property using {"ref":1} instead of {ref:1}. The Chrome C++ JSON parser implementation requires quoted property names.
Changed the JSON format for non finite numbers. The previous formatting using NaN, Infinite and -Infinite caused the Chrome C++ JSON parser implementation to fail. Values "NaN", "Infinite" and "-Infinite" (incuding quotes) are now used.
Reverted changes to DebugLookupResultValue (runtime.cc) from http://codereview.chromium.org/17377. The change caused callback into Chrome with the current V8 context expected to have a DOM Window global object. This is not the case when the debugger context is the active context. This causes properties from interceptors and accessors to be reported as undefined in the debugger.
Review URL: http://codereview.chromium.org/18194
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1101 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
instead of normal JSObjects.
This ensures that __proto__ and accessors on the Object prototype do
not interfere with catch scopes. Also, it fixes the bug that catch
variables were not DontDelete (issue 74).
Next step is to create special lookup routines for context extension
objects and remove the special handling of context extension objects
from the general javascript object lookup routines.
Review URL: http://codereview.chromium.org/18143
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1091 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Properties from interceptors are also reflected through PropertyMirror as the distinction did not make sense seen from a JavaScript debugging perspective. The isNative function on a PropertyMirror can be used to check whether a property is defined natively by the host (or V8).
Simplified the local property lookup in the debug runtime call to just call GetProperty as the property is known to be a local property.
Review URL: http://codereview.chromium.org/17377
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1068 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Here is a description of the background and design of split window in Chrome and V8:
https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr
This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables.
V8 support of split window:
There are a small number of changes on V8 api to support split window:
Security context is removed from V8, so does related API functions;
A global object can be detached from its context and reused by a new context;
Access checks on an object template can be turned on/off by default;
An object can turn on its access checks later;
V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc.
Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object.
When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks.
It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding.
I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8.
Review URL: http://codereview.chromium.org/7366
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
upper case. Moved it into the RelocInfo class together with the associated
is_xxx functions. Renamed is_xxx to IsXxx in the process.
Removed the exit_js_frame mode as it was no longer used.
Patch Set 2 renames RELOC_MODE_COUNT to NUMBER_OF_MODES and fixes a couple of lint errors.
Review URL: http://codereview.chromium.org/3186
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@354 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Make old_data_space non-executable on OSs and hardware that support it.
* Rename old_space to old_pointer_space (can contain pointers, esp. to new space).
* Ensure that individual pages allocated for old_space are only executable when
they are for code objects.
* Ensure Space::Setup can cope with non-aligned memory.
* Make some methods on Spaces virtual. Make a way to iterate over all spaces.
* Replace executability flag with Executability enum in order to make intent at
call site clearer.
* Fix serialization/deserialization to allocate write barrier memory for large
arrays.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@165 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
while V8 is running.
A debugger using the V8 message based interface now needs to control the
call to DebugBreak in order for the messages send to be processed. Commands can
still be send when V8 is not in a break, but they will not be processed until
there is a break. The response "request queued" when queuing up messages have
been removed. This gets rid of a non JSON message being used.
Modified the threaded debugger tests to call DebugBreak instead of relying
on it occouring automatically.
This change will not be committed until the outstanding Chrome change
http://chrome-reviews.prom.corp.google.com/2072 (which updates Chrome to control
the DebugBreak call) have been reviewed and committed.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@47 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added better test support.
Added load, quit and version functions to the shell sample so it's easier to run benchmarks and tests.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In the shell sample don't print the result of executing a script, only
evaluating expressions.
Fixed issue when building samples on Windows using a shared V8
library. Added visibility option on Linux build which makes the
generated library 18% smaller.
Changed build system to accept multiple build modes in one build and
generate seperate objects, libraries and executables for each mode.
Removed deferred negation optimization (a * -b => -(a * b)) since this
visibly changes operand conversion order.
Improved parsing performance by introducing stack guard in preparsing.
Without a stack guard preparsing always bails out with stack overflow.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
