Fix FuncNameInferrer usage in ParseAssignmentExpression

Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y

Committed: https://crrev.com/eb67f85439dcc273501e9fba5a9e883585505aa8
Cr-Commit-Position: refs/heads/master@{#32768}

[adamk, 2015-12-09 23:04:46]

Description was changed from

==========
FuncNameInferrer shouldn't check the length of AstConsStrings repeatedly

BUG=v8:4595
LOG=n
==========

to

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode still, so I've skipped it there.

BUG=v8:4595
LOG=y
==========

[adamk, 2015-12-09 23:05:08]

adamk@chromium.org changed reviewers:
+ littledan@chromium.org

[Dan Ehrenberg, 2015-12-10 01:06:23]

You were suggesting off-line that RAII would've made this a lot easier to
prevent. Do you want to do that cleanup as part of this patch?

[adamk, 2015-12-10 01:56:43]

Description was changed from

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode still, so I've skipped it there.

BUG=v8:4595
LOG=y
==========

to

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y
==========

[adamk, 2015-12-10 01:56:53]

RAII'd

https://codereview.chromium.org/1507283003/diff/40001/src/parsing/parser.cc
File src/parsing/parser.cc (left):

https://codereview.chromium.org/1507283003/diff/40001/src/parsing/parser.cc#o...
src/parsing/parser.cc:2588: if (single_name && fni_ != NULL) fni_->Leave();
Pretty sure this was a bug before.

[Dan Ehrenberg, 2015-12-10 18:22:41]

lgtm

I really like this more comprehensive fix

https://codereview.chromium.org/1507283003/diff/40001/src/parsing/parser.cc
File src/parsing/parser.cc (left):

https://codereview.chromium.org/1507283003/diff/40001/src/parsing/parser.cc#o...
src/parsing/parser.cc:2588: if (single_name && fni_ != NULL) fni_->Leave();
On 2015/12/10 at 01:56:53, adamk wrote:
> Pretty sure this was a bug before.

Awesome!

[adamk, 2015-12-10 19:17:28]

The CQ bit was checked by adamk@chromium.org

[commit-bot: I haz the power, 2015-12-10 19:17:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1507283003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1507283003/40001

[commit-bot: I haz the power, 2015-12-10 19:18:59]

Description was changed from

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y
==========

to

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y
==========

[commit-bot: I haz the power, 2015-12-10 19:18:59]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-12-10 19:19:42]

Description was changed from

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y
==========

to

==========
Fix FuncNameInferrer usage in ParseAssignmentExpression

Without this fix, AssignmentExpressions that happen to be arrow functions
would lead to unbalanced Enter/Leave calls on the fni_, causing thrashing
while trying to infer function names. Symptoms include slow parsing
or OOM (when we create too many AstConsStrings).

To try to keep this from happening in the future, added an RAII helper
class to handle Entering/Leaving FNI state.

The included regression test crashes on my workstation without the patch.
Note that it's too slow in debug mode (as well as under TurboFan),
so I've skipped it there.

BUG=v8:4595
LOG=y

Committed: https://crrev.com/eb67f85439dcc273501e9fba5a9e883585505aa8
Cr-Commit-Position: refs/heads/master@{#32768}
==========

[commit-bot: I haz the power, 2015-12-10 19:19:43]

Patchset 3 (id:??) landed as
https://crrev.com/eb67f85439dcc273501e9fba5a9e883585505aa8
Cr-Commit-Position: refs/heads/master@{#32768}