[type profile] Collect return types.

Collect type information of return values.

Use *one* feedback slot per function for all its return
statements. For assignments, we currently use
several slots per function, because not all
assignments refer to the same variable.

Instead of the variable names, pass the
source location and print the function name.

Add an integration test for --type-profile that checks
for crashes.

Remove type feedback for assignments for now as it convolutes the output.

************ Function with 2 return statements ********
function testFunction(param, flag) {
  // We want to test 2 different return positions in one function.
  if (flag) {
    var first_var = param;
    return first_var;
  var second_var = param;
  return second_var;

testFunction(123, true);

************* Sample Output ***************************
Function: testFunction
424: Object
374: number
424: string
424: undefined

Missing work:
* Handle fall-off returns
* Collect types for parameters
* Remove duplicates from the list of collected types and use a common base class.


Review-Url: https://codereview.chromium.org/2755973002
Cr-Commit-Position: refs/heads/master@{#43956}
14 files changed
tree: 61179e3de7618d21d63ed3c98e526f3431f6c8f2
  1. .clang-format
  2. .gitignore
  3. .gn
  4. .ycm_extra_conf.py
  6. BUILD.gn
  8. ChangeLog
  9. DEPS
  11. LICENSE.fdlibm
  12. LICENSE.strongtalk
  13. LICENSE.v8
  14. LICENSE.valgrind
  15. Makefile
  16. Makefile.android
  17. OWNERS
  18. PRESUBMIT.py
  19. README.md
  21. benchmarks/
  22. build_overrides/
  23. codereview.settings
  24. docs/
  25. gni/
  26. gypfiles/
  27. include/
  28. infra/
  29. samples/
  30. snapshot_toolchain.gni
  31. src/
  32. test/
  33. testing/
  34. third_party/
  35. tools/

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://github.com/v8/v8/wiki

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

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/*


Please follow the instructions mentioned on the V8 wiki.