[wasm] Adjust crash message of the correctness fuzzer to avoid clustering.

[wasm] Adjust crash message of the correctness fuzzer to avoid clustering.

The correctness fuzzer executes the input array in two different
execution engines and compares the results. If the results don't match,
the correctness fuzzer crashes.

Since the crash signature is always the same if the results don't match,
cluster fuzz would group all inputs which lead to non-matching results.

To avoid the grouping a base64 hash has to be appended to the crash
signature. This CL changes the text which is appended to the crash
signature to a base64 hash.

Note that I do not create a base64 hash directly because the base64
class is not available in V8. Instead I create a string which looks
like a base64 hash.

R=mmoroz@chromium.org, aarya@chromium.org, titzer@chromium.org

Committed: https://crrev.com/55da769bafac8b531cd8b388df56161b8b7c6416
Cr-Commit-Position: refs/heads/master@{#39953}

[ahaas, 2016-10-04 10:02:55]

The CQ bit was checked by ahaas@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-04 10:03:04]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-04 10:26:14]

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

[commit-bot: I haz the power, 2016-10-04 10:26:15]

Dry run: This issue passed the CQ dry run.

[mmoroz, 2016-10-04 11:00:29]

LGTM, hope it will work as we expect

[titzer, 2016-10-04 12:12:33]

lgtm.

We might have to explore a bit more to get the right clustering.

[ahaas, 2016-10-04 12:15:16]

The CQ bit was checked by ahaas@chromium.org

[commit-bot: I haz the power, 2016-10-04 12:15:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-04 12:17:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-04 12:18:19]

Description was changed from

==========
[wasm] Adjust crash message of the correctness fuzzer to avoid clustering.

The correctness fuzzer executes the input array in two different
execution engines and compares the results. If the results don't match,
the correctness fuzzer crashes.

Since the crash signature is always the same if the results don't match,
cluster fuzz would group all inputs which lead to non-matching results.

To avoid the grouping a base64 hash has to be appended to the crash
signature. This CL changes the text which is appended to the crash
signature to a base64 hash.

Note that I do not create a base64 hash directly because the base64
class is not available in V8. Instead I create a string which looks
like a base64 hash.

R=mmoroz@chromium.org, aarya@chromium.org, titzer@chromium.org
==========

to

==========
[wasm] Adjust crash message of the correctness fuzzer to avoid clustering.

The correctness fuzzer executes the input array in two different
execution engines and compares the results. If the results don't match,
the correctness fuzzer crashes.

Since the crash signature is always the same if the results don't match,
cluster fuzz would group all inputs which lead to non-matching results.

To avoid the grouping a base64 hash has to be appended to the crash
signature. This CL changes the text which is appended to the crash
signature to a base64 hash.

Note that I do not create a base64 hash directly because the base64
class is not available in V8. Instead I create a string which looks
like a base64 hash.

R=mmoroz@chromium.org, aarya@chromium.org, titzer@chromium.org

Committed: https://crrev.com/55da769bafac8b531cd8b388df56161b8b7c6416
Cr-Commit-Position: refs/heads/master@{#39953}
==========

[commit-bot: I haz the power, 2016-10-04 12:18:20]

Patchset 1 (id:??) landed as
https://crrev.com/55da769bafac8b531cd8b388df56161b8b7c6416
Cr-Commit-Position: refs/heads/master@{#39953}