When the page is controlled by a ServiceWorker, the ServiceWorker can return an opaque (non-CORS cross origin) resource response.
We need to treat the messages from such script resource as opaque.
Committed: https://crrev.com/7a599c5e1242d3c5ab7515ee149623da90ae69ec
Cr-Commit-Position: refs/heads/master@{#28445}
Review URL: https://codereview.chromium.org/1140673002
Cr-Commit-Position: refs/heads/master@{#28459}
When the page is controlled by a ServiceWorker, the ServiceWorker can return an opaque (non-CORS cross origin) resource response.
We need to treat the messages from such script resource as opaque.
Review URL: https://codereview.chromium.org/1140673002
Cr-Commit-Position: refs/heads/master@{#28445}
Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
BUG=chromium:481845
LOG=Y
Review URL: https://codereview.chromium.org/1134193002
Cr-Commit-Position: refs/heads/master@{#28371}
Reason for revert:
GC mole issues: https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux%20-%20gcmole/builds/1950/steps/GCMole%20ia32/logs/stdio
Original issue's description:
> Provide accessor for object internal properties that doesn't require debugger to be active
>
> Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
>
> Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
>
> BUG=chromium:481845
> LOG=Y
>
> Committed: https://crrev.com/bdeb0de88c8cf5f2c78f261b45314138f525110d
> Cr-Commit-Position: refs/heads/master@{#28362}
TBR=pfeldman@chromium.org,kozyatinskiy@chromium.org,yurys@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:481845
Review URL: https://codereview.chromium.org/1133243002
Cr-Commit-Position: refs/heads/master@{#28365}
Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
BUG=chromium:481845
LOG=Y
Review URL: https://codereview.chromium.org/1126103006
Cr-Commit-Position: refs/heads/master@{#28362}
If there had been no debug listener v8::Debug::GetDebugContext would have created new context and wouln't have kept reference to it. This way we may well end up with several debug contexts and disabled debugger.
As a side effect this change allows to efficiently distinguish debug context from blink contexts by simply comparing handles.
BUG=chromium:482290
LOG=Y
Review URL: https://codereview.chromium.org/1136733002
Cr-Commit-Position: refs/heads/master@{#28356}
Exposed to the extras as extrasExports (on the builtins object), on
which they can put things that should be accessible from C++. Exposed
to C++ through the V8 API as v8::Context::GetExtrasExportsObject().
Adding a test (in test-api.cc) required adding a simple extra,
test-extra.js, which we build into the standalone builds.
R=yangguo@chromium.org, jochen@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1128113006
Cr-Commit-Position: refs/heads/master@{#28317}
I know the bug has been closed but this seems like a simple addition that may
be useful in other ways as well.
BUG=v8:2180
LOG=N
Review URL: https://codereview.chromium.org/1128553002
Cr-Commit-Position: refs/heads/master@{#28261}
These macros are not needed anymore, so there's no point in supporting
them.
Review URL: https://codereview.chromium.org/1123723003
Cr-Commit-Position: refs/heads/master@{#28214}
Just give internal ones an ArrayBuffer with a NULL backing store. This
simplifies the access checks a lot.
BUG=v8:3996
R=hpayer@chromium.org,verwaest@chromium.org
LOG=n
Review URL: https://codereview.chromium.org/1109353003
Cr-Commit-Position: refs/heads/master@{#28168}
We shouldn't have shared state between isolates by default. The embedder
is free to pass the same allocator to all isolates it creates.
BUG=none
R=dcarney@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1116633002
Cr-Commit-Position: refs/heads/master@{#28127}
For dumping memory statistics about v8 heap, we need the total
available size of the heap. This CL adds extra field in HeapStatistics
to return the available size.
BUG=476013
LOG=Y
Review URL: https://codereview.chromium.org/1104123002
Cr-Commit-Position: refs/heads/master@{#28100}
The embedder has to take appropriate steps to ensure that the
ArrayBuffer doesn't die while it's accessing the pointer, e.g. keep a
Local handle to it around
BUG=none
R=dslomov@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1095083002
Cr-Commit-Position: refs/heads/master@{#27942}
This class was added in crrev.com/1058253003 and missed V8_EXPORT in
definition.
BUG=466141, 476013
LOG=Y
Review URL: https://codereview.chromium.org/1090333002
Cr-Commit-Position: refs/heads/master@{#27926}
This is first step towards adding V8 heap statistics to the memory
tracing infrastructure. For being able to get useful memory number into
the memory dump, v8 needs to provide an external api needs to obtain
more information about the heap. So, this Cl extends the api to give
information about the memory allocated and used in the spaces.
BUG=466141, 476013
LOG=Y
Review URL: https://codereview.chromium.org/1058253003
Cr-Commit-Position: refs/heads/master@{#27919}
The embedder can control how many threads it wants to use via the
v8::Platform implementation. V8 internally doesn't spin up threads
anymore. If the embedder doesn't want to use any threads at all, it's
v8::Platform implementation must either run the background jobs on
the foreground thread, or the embedder should specify --predictable
BUG=none
R=yangguo@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1064723005
Cr-Commit-Position: refs/heads/master@{#27833}
As uClibc defines __GLIBC__ in an attempt to look like glibc, V8_LIBC_GLIBC
was true for uClibc as well. Checking for uClibc before glibc fixes this
and restores the correct behavior.
BUG=
Review URL: https://codereview.chromium.org/1066573005
Cr-Commit-Position: refs/heads/master@{#27806}
This allows the embedder to decide whether it's worthwhile to copy the
contents to avoid materializing a buffer.
BUG=v8:3996
R=dslomov@chromium.org,kbr@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1084513002
Cr-Commit-Position: refs/heads/master@{#27782}
When debugging Handle leaks in io.js we found it very convenient to be
able to Seal some specific (root in our case) scope to prevent Handle
allocations in it, and easily find leakage.
R=yangguo
BUG=
Review URL: https://codereview.chromium.org/1079713002
Cr-Commit-Position: refs/heads/master@{#27766}
gcc rejects the following snippet, clang rejects it in -std=c++11 mode:
namespace A { template<class T> class C {}; }
namespace B { template class A::C<int>; }
Indeed, the C++ standard says in 14.7.2p2 "An explicit instantiation shall
appear in an enclosing namespace of its template", so cl.exe is incorrect to
allow this.
Just move the instantiation out of the v8 namespace to fix. No intended
behavior change. Fixes building with clang-cl on Windows.
BUG=chromium:475643
LOG=N
TBR=svenpanne@chromium.org
Review URL: https://codereview.chromium.org/1073903002
Cr-Commit-Position: refs/heads/master@{#27721}
Reason for revert:
Causes test failures on ARM bots related to cells and write barriers.
Original issue's description:
> Merge cellspace into old pointer space
>
> BUG=
>
> Committed: https://crrev.com/4e7163ce05f135918205c7855ae60a48e5d46cc5
> Cr-Commit-Position: refs/heads/master@{#27707}
TBR=hpayer@chromium.org,balazs.kilvady@imgtec.com,yangguo@chromium.org,verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1053243003
Cr-Commit-Position: refs/heads/master@{#27711}
Instead, please use v8::Isolate::RequestInterrupt to synchronize
to the main thread.
R=yurys@chromium.org
API=Removed v8::Debug::DebugBreakForCommand
LOG=Y
Review URL: https://codereview.chromium.org/1036863002
Cr-Commit-Position: refs/heads/master@{#27625}
The motivation is that we prefer to avoid creating internal properties, and we have a usable field on maps ("transitions", which is not used for prototype maps).
This CL also ensures the invariant that prototype maps are never shared, even if they are in dictionary mode.
Review URL: https://codereview.chromium.org/1033653002
Cr-Commit-Position: refs/heads/master@{#27617}
It triggers once per context that calls observe (or attempts to access
any observation metadata, e.g. through Object.getNotifier).
Review URL: https://codereview.chromium.org/1048213002
Cr-Commit-Position: refs/heads/master@{#27557}
Before this patch the embedder could assign timestamp to the last interval after calling GetHeapStats. This would be slightly different from the timstamps assigned by v8 internally and written into heap snapshot. This patch allow to avoid this small discrepancy by returning timestamp along with last heap stats update.
BUG=chromium:467222
LOG=Y
Review URL: https://codereview.chromium.org/1037803002
Cr-Commit-Position: refs/heads/master@{#27466}
If the Maybe is nothing or the MaybeLocal is empty, it means that the
API call either threw an exception or an exception was already pending.
In that case, the embedder needs to handle the exception or otherwise
react to the failed API call.
BUG=v8:3929
R=svenpanne@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1022803002
Cr-Commit-Position: refs/heads/master@{#27298}
Some native counters (e.g. KeyedLoadGenericSlow) are referenced from stubs that are generated very early in the Isolate lifecycle before v8::Isolate::New returns. Thus counter lookup callback also needs to be installed early prior to v8::internal::Isolate::Init call. Otherwise assembler will just assume that the counter is not enabled and produce no code from IncrementCounter - because address of the counter is not yet available.
Histogram related callbacks are moved for consistency to make them able to collect samples which occur at isolate initialization time.
BUG=
Review URL: https://codereview.chromium.org/1010233002
Cr-Commit-Position: refs/heads/master@{#27262}
It should be possible to cast a Value to Int32 without throwing an exception
when IsInt32() is true. Same for Uint32.
BUG=chromium:462402
LOG=Y
Review URL: https://codereview.chromium.org/1003663002
Cr-Commit-Position: refs/heads/master@{#27156}
This removes the separate tracking of the pending message script,
because that script is already stored in the message object and
duplicating it in the ThreadLocalTop makes it more brittle.
R=bmeurer@chromium.org
Review URL: https://codereview.chromium.org/995013005
Cr-Commit-Position: refs/heads/master@{#27127}
We should be able to cast a Value to Boolean when IsBoolean() is true.
Review URL: https://codereview.chromium.org/990943003
Cr-Commit-Position: refs/heads/master@{#27124}
None of these fields is used in Blink. Embedder always can implement them using existing API.
BUG=chromium:465651
LOG=Y
Review URL: https://codereview.chromium.org/983833006
Cr-Commit-Position: refs/heads/master@{#27113}
This makes sure that the pending message location is only tracked by
the message object, as only this is saved for finally-blocks. The
location information is duplicated and becomes stale.
R=titzer@chromium.org
TEST=maeh, not so much.
Review URL: https://codereview.chromium.org/987353002
Cr-Commit-Position: refs/heads/master@{#27109}
since the old style weakness is slated for removal, we might as well reuse the name to limit confusion. additionally I simplified the callback type to a enum to either get internal field values or not
this should be a non-breaking change with the exception of PhantomPersistentValueMap, which is unused.
R=jochen@chromium.org, erikcorry@chromium.org
BUG=
Review URL: https://codereview.chromium.org/989153003
Cr-Commit-Position: refs/heads/master@{#27084}
This keeps dying maps alive for FLAG_retain_maps_for_n_gc garbage collections
to increase chances of them being reused for new objects in future and
decrease number of deoptimizations.
BUG=v8:3664
LOG=N
TEST=cctest/test-heap/MapRetaining
Review URL: https://codereview.chromium.org/980523004
Cr-Commit-Position: refs/heads/master@{#27040}
According to Source Map specification [1] source map url can be passed either as a magic comment at the end of script or as SourceMap http header. We already parse the former value and expose it on Script object. This change allows to unify the way we deal with source map urls received in http header by providing api for passing that url into the script being compiled.
source_map_url is intentionally not passed into CompilationCacheScript::Lookup. The cache is anyways disabled when debugger is on.
[1] https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit
LOG=Y
BUG=chromium:462572
Review URL: https://codereview.chromium.org/983603003
Cr-Commit-Position: refs/heads/master@{#27017}
Side note: tools/v8-info.sh seems to have been broken ever
since the move to git. At least it's not more broken now.
BUG=v8:3075
LOG=y
TEST=./script_test.py
Review URL: https://codereview.chromium.org/959713003
Cr-Commit-Position: refs/heads/master@{#26873}
This adds an "experimental" API hook (v8::ScriptCompiler::CompileModule)
allowing compilation of modules. The code gen is incredibly basic: the
module body is represented by a Block in the AST. But this at least gets
more of the pipeline working, and opens the door to writing mjsunit tests
(once d8 is modified to support module compilation).
BUG=v8:1569
LOG=n
Review URL: https://codereview.chromium.org/902093002
Cr-Commit-Position: refs/heads/master@{#26496}
A new map wich references its keys weakly is added to v8.h. Internally it uses the same storage as JSWeakMap but doesn't depend on the JavaScript part of WeakMap implementation in weak-collection.js, hence it can be instantiated without entering any context.
BUG=chromium:437416
LOG=Y
Review URL: https://codereview.chromium.org/900123003
Cr-Commit-Position: refs/heads/master@{#26451}
When embedder detaches the global objects, its context must be garbage
collected eventually.
BUG=
Review URL: https://codereview.chromium.org/898663005
Cr-Commit-Position: refs/heads/master@{#26450}
A new map wich references its keys weakly is added to v8.h. Internally it uses the same storage as JSWeakMap but doesn't depend on the JavaScript part of WeakMap implementation in weak-collection.js, hence it can be instantiated without entering any context.
BUG=chromium:437416
LOG=Y
Review URL: https://codereview.chromium.org/891473005
Cr-Commit-Position: refs/heads/master@{#26425}
A new map wich references its keys weakly is added to v8.h. Internally it uses the same storage as JSWeakMap but doesn't depend on the JavaScript part of WeakMap implementation in weak-collection.js, hence it can be instantiated without entering any context.
BUG=chromium:437416
LOG=Y
Review URL: https://codereview.chromium.org/886473005
Cr-Commit-Position: refs/heads/master@{#26401}
When --vector-ics is true, we still tail-call to the hand-written
megamorphic KeyedLoadIC (formerly "generic"). Now that this code uses
the megamorphic cache, it needs to deal properly with the vector and
slot registers. Achieve this with a sentinel vectors/slot combo.
R=dcarney@chromium.org
BUG=
Review URL: https://codereview.chromium.org/892173002
Cr-Commit-Position: refs/heads/master@{#26381}
Contribution of PowerPC port (continuation of 422063005 and 817143002). This patch covers
the key changes needed to the common files needed to support AIX. Subsequent
patches will cover:
- changes to update the ppc directories so they are current with the changes
in the rest of the project.
- remaining AIX changes not resolved by 4.8 compiler
- individual optimizations for PPC
This is based off of the GitHub repository
https://github.com/andrewlow/v8ppcR=danno@chromium.org, svenpanne@chromium.org
BUG=
Review URL: https://codereview.chromium.org/866843003
Cr-Commit-Position: refs/heads/master@{#26343}
In DevTools we need one more flag for script origin - is debugger script. We already have "is shared origin" flag. The new flag added by analogy with the old but new has accessor in script object.
R=yurys@chromium.org
Review URL: https://codereview.chromium.org/879553002
Cr-Commit-Position: refs/heads/master@{#26324}
This method circumvented JS semantics, and should not be used.
BUG=
Review URL: https://codereview.chromium.org/854493004
Cr-Commit-Position: refs/heads/master@{#26157}
Support for it is slow and difficult to implement, and it's not used in
Blink. An embedder that uses this feature will have to check the
argument types itself.
BUG=none
R=dcarney@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/848173002
Cr-Commit-Position: refs/heads/master@{#26058}
This API is used by Blink to inform V8 about HTML frames being disposed.
Using the optional parameter, Blink can tell V8 whether the disposed
frame was a main frame. In that case, we might want to reset GC
parameters
BUG=none
R=hpayer@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/823583003
Cr-Commit-Position: refs/heads/master@{#25926}
There might be a number of clients that would like to
setup an interrupt request on the Isolate.
The patch also deprecates ClearInterrupt API. As long as
the interrupt handler is called outside of locks there's no way
to guarantee that the handler will not be called after
ClearInterrupt was invoked as it might have already started execution.
Review URL: https://codereview.chromium.org/796623003
Cr-Commit-Position: refs/heads/master@{#25910}
v8::Object already has GetIdentityHash on it. This change adds its counterpart to v8::Name.
BUG=chromium:437416
LOG=Y
Review URL: https://codereview.chromium.org/753373003
Cr-Commit-Position: refs/heads/master@{#25598}
Also, remove V8_CC_CLANG since it's not read anywhere (and ideally shouldn't
be).
Clang tries to be compatible with gcc in clang mode, and with msvc in clang-cl
mode. It wants to go down the same code paths that these compilers want to go
down in most cases.
For example, V8PRIxPTR was set incorrectly on Windows 64-bit before this change
since macros.h assumed that checking for V8_CC_MSVC is enough to find LLP64
systems, but V8_CC_MSVC wasn't set for clang. Most other existing checks for
V8_CC_MSVC should be taken for clang-cl too (and for the remaining ones,
clang-cl is happy with either code path).
Likewise, V8_IMMEDIATE_CRASH is currently set to a suboptimal value with clang
since __builtin_trap() is only used if V8_CC_GNU is set.
Including clang in the gcc and cl macros is also what chromium does.
BUG=chromium:82385
LOG=y
Review URL: https://codereview.chromium.org/757553004
Cr-Commit-Position: refs/heads/master@{#25592}
Reduces dependencies on #include files, making it easier for other
build systems to include this library.
BUG=
Review URL: https://codereview.chromium.org/740493002
Cr-Commit-Position: refs/heads/master@{#25408}
This implements correct semantics for "extensible" top level lexical scope.
The entire lexical scope is represented at runtime by GlobalContextTable, reachable from native context and accumulating global contexts from every script loaded into the context.
When the new script starts executing, it does the following validation:
- checks the GlobalContextTable and global object (non-configurable own) properties against the set of declarations it introduces and reports potential conflicts.
- invalidates the conflicting PropertyCells on global object, so that any code depending on them will miss/deopt causing any contextual lookups to be reexecuted under the new bindings
- adds the lexical bindings it introduces to the GlobalContextTable
Loads and stores for contextual lookups are modified so that they check the GlobalContextTable before looking up properties on global object, thus implementing the shadowing of global object properties by lexical declarations.
R=adamk@chromium.org, rossberg@chromium.org
Review URL: https://codereview.chromium.org/705663004
Cr-Commit-Position: refs/heads/master@{#25220}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25220 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
During generation code and relocation info are generated simultaneously.
When code generation is done you each code object has associated "relocation info".
Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection),
correspondences between the machine program counter and source locations for stack walking.
This patch:
1. Add more source positions info in reloc info to make it suitable for source level mapping.
The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and
(2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other).
I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark).
2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line.
If a source line is found that hit counter is increased by one for this line.
3. Add a new public V8 API to get the hit source lines by CDT CPU profiler.
Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown.
4.Add a test that checks how the samples are distributed through source lines.
It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version.
Patch from Denis Pravdin <denis.pravdin@intel.com>;
R=svenpanne@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/682143003
Patch from Weiliang <weiliang.lin@intel.com>.
Cr-Commit-Position: refs/heads/master@{#25182}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Updates Object.prototype.toString() to use algorithm described in harmony drafts.
Currently, the behaviour is essentially the same as ES262's version, however this changes when internal structures
such as Promise make use of symbolToStringTag (as they are supposed to, see v8:3241), and changes further once
Symbol.toStringTag is exposed publicly.
BUG=v8:3241, v8:3502
LOG=N
R=dslomov@chromium.org
Review URL: https://codereview.chromium.org/546803003
Patch from Caitlin Potter <caitpotter88@gmail.com>.
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Reason for revert:
It broke layout test fast/events/window-onerror-02.html, error column reported by window.onerror is now wrong (I believe it is because of the change in full-codegen):
http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg%29/builds/652
Original issue's description:
> Extend CPU profiler with mapping ticks to source lines
>
> The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers.
> During generation code and relocation info are generated simultaneously.
> When code generation is done you each code object has associated "relocation info".
> Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection),
> correspondences between the machine program counter and source locations for stack walking.
>
> This patch:
> 1. Add more source positions info in reloc info to make it suitable for source level mapping.
> The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and
> (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other).
> I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark).
>
> 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line.
> If a source line is found that hit counter is increased by one for this line.
>
> 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler.
> Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown.
>
> 4.Add a test that checks how the samples are distributed through source lines.
> It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version.
>
> Patch from Denis Pravdin <denis.pravdin@intel.com>
> BUG=None
> LOG=Y
> R=svenpanne@chromium.org
>
> Committed: https://code.google.com/p/v8/source/detail?r=24389TBR=svenpanne@chromium.org,danno@chromium.org,alph@chromium.org,denis.pravdin@intel.com,weiliang.lin@intel.com
BUG=None
LOG=N
Review URL: https://codereview.chromium.org/624443005
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24394 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers.
During generation code and relocation info are generated simultaneously.
When code generation is done you each code object has associated "relocation info".
Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection),
correspondences between the machine program counter and source locations for stack walking.
This patch:
1. Add more source positions info in reloc info to make it suitable for source level mapping.
The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and
(2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other).
I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark).
2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line.
If a source line is found that hit counter is increased by one for this line.
3. Add a new public V8 API to get the hit source lines by CDT CPU profiler.
Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown.
4.Add a test that checks how the samples are distributed through source lines.
It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version.
Patch from Denis Pravdin <denis.pravdin@intel.com>
BUG=None
LOG=Y
R=svenpanne@chromium.org
Review URL: https://codereview.chromium.org/616963005
Patch from Denis Pravdin <denis.pravdin@intel.com>.
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24389 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
