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svenpanne@chromium.org d56a21ebff 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>;

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
2014-11-06 09:17:14 +00:00
benchmarks Revert "Refactoring: Make gtest testsuite the default." 2014-09-02 09:17:26 +00:00
build Remove deprecated lexer-shell. 2014-10-23 11:42:30 +00:00
include The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. 2014-11-06 09:17:14 +00:00
samples Reland 24052 - Require V8 to be explicitly initialized before an Isolate is created 2014-09-19 08:01:35 +00:00
src The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. 2014-11-06 09:17:14 +00:00
test The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. 2014-11-06 09:17:14 +00:00
testing Remove v8stdint.h, it doesn't serve a purpose anymore. 2014-10-21 08:25:14 +00:00
tools Whitespace change to trigger bots (5) 2014-11-05 22:09:11 +00:00
.clang-format Change clang-format config to allow for two empty lines between functions 2013-12-03 10:39:21 +00:00
.DEPS.git Add android tools to v8's deps. 2014-08-28 11:09:46 +00:00
.gitignore Make GIT ignore all turbo.cfg files. 2014-10-23 16:11:56 +00:00
AUTHORS Improve String.repeat. 2014-10-17 10:01:38 +00:00
BUILD.gn Introduce Diamond, a helper for building diamond-shaped control patterns. 2014-11-04 14:37:44 +00:00
ChangeLog Sync change log file with trunk. 2014-05-19 15:29:29 +00:00
codereview.settings Add PROJECT to v8 2014-06-23 15:33:19 +00:00
DEPS Add android tools to v8's deps. 2014-08-28 11:09:46 +00:00
LICENSE Update LICENSE date. 2014-02-18 10:50:22 +00:00
LICENSE.strongtalk Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.v8 Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.valgrind Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
Makefile Add turbocheck Makefile target. 2014-10-31 08:39:43 +00:00
Makefile.android Update toolchain for Android mipsel, ia32, x87. 2014-08-19 11:20:42 +00:00
Makefile.nacl Use the pnacl-clang toolchain for (P)NaCL builds 2014-10-06 08:10:50 +00:00
OWNERS Revoke my own OWNERS bit. 2014-10-28 23:47:39 +00:00
PRESUBMIT.py Add a PRESUBMIT check that production code does not call test code 2014-09-23 08:14:06 +00:00
README.md Add README.md file 2014-10-20 11:37:06 +00:00
WATCHLISTS Add myself to a watchlist for the public API. 2013-10-10 11:37:48 +00:00

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://code.google.com/p/v8/

Getting the Code

V8 Git repository: https://chromium.googlesource.com/v8/v8.git GitHub mirror: https://github.com/v8/v8-git-mirror

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*