Show references from weak containers as weak in heap snapshots.

Show references from weak containers as weak in heap snapshots.

BUG=356590
LOG=Y
R=ulan@chromium.org, yurys@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=20429

[alph, 2014-04-01 15:38:53]

ptal

[yurys, 2014-04-01 15:51:54]

lgtm,

would be nice to have a test for these cases

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator.cc
File src/heap-snapshot-generator.cc (right):

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator....
src/heap-snapshot-generator.cc:1152: HeapEntry* heap_entry = GetEntry(obj);
Consider extracting common prologue and epilogue of ExtractReferencesPass{1,2} 
into IterateAndExtractSinglePass.

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator....
src/heap-snapshot-generator.cc:2189: if (IsEssentialObject(object)) {
Can you add an assert that the object passed in is a FixedArray or change the
parameter type to FixedArray?

[alph, 2014-04-01 16:30:03]

Ulan, could you please take a look.

Also do you know a non-flaky way to obtain a weak FixedArray container on a heap
object for the test purposes?

Thanks

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator.cc
File src/heap-snapshot-generator.cc (right):

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator....
src/heap-snapshot-generator.cc:1152: HeapEntry* heap_entry = GetEntry(obj);
On 2014/04/01 15:51:55, yurys wrote:
> Consider extracting common prologue and epilogue of ExtractReferencesPass{1,2}

> into IterateAndExtractSinglePass.

Done.

https://codereview.chromium.org/213673006/diff/1/src/heap-snapshot-generator....
src/heap-snapshot-generator.cc:2189: if (IsEssentialObject(object)) {
On 2014/04/01 15:51:55, yurys wrote:
> Can you add an assert that the object passed in is a FixedArray or change the
> parameter type to FixedArray?

Done.

[ulan, 2014-04-01 17:28:36]

lgtm!

> Also do you know a non-flaky way to obtain a weak FixedArray container on a
heap
> object for the test purposes?

function foo(a) {
  return a.x;
}

var obj = {x : 1};

foo(obj);
foo(obj);
%OptimizeFunctionOnNextCall(foo);
foo(obj);

Now the map of obj will contain dependent_code with the optimized code of foo.

[alph, 2014-04-02 11:14:05]

The CQ bit was checked by alph@chromium.org

[commit-bot: I haz the power, 2014-04-02 11:14:15]

CQ is trying da patch. Follow status at
https://v8-status.appspot.com/cq/alph@chromium.org/213673006/40001

[commit-bot: I haz the power, 2014-04-02 11:14:15]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-02 11:14:16]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[alph, 2014-04-02 11:20:25]

Committed patchset #3 manually as r20429 (presubmit successful).