Preparse functions in the scope that was created when parsing of the function was started

Preparse functions in the scope that was created when parsing of the function was started

This reduces the number of scopes for lazily parsed top-level functions from 3 to 1

BUG=v8:5209
Committed: https://crrev.com/9618d095903c604a032b33792c068f4a6169503c
Cr-Commit-Position: refs/heads/master@{#39725}

[Toon Verwaest, 2016-09-26 12:24:12]

verwaest@chromium.org changed reviewers:
+ marja@chromium.org

[Toon Verwaest, 2016-09-26 12:24:12]

ptal

[marja, 2016-09-26 12:38:27]

https://codereview.chromium.org/2370713003/diff/1/src/ast/scopes.h
File src/ast/scopes.h (right):

https://codereview.chromium.org/2370713003/diff/1/src/ast/scopes.h#newcode809
src/ast/scopes.h:809: void ResetAfterPreparsing() {
Why do we need this? Just by reading the code, it's unclear to me 1) is this
something that needs to be done for correctness or is it just cleaning up things
we don't need to save memory? 2) why does it clear exactly these things and not
some other things?

(Adding a comment here w/ the answer is welcome. :))

https://codereview.chromium.org/2370713003/diff/1/src/parsing/parser-base.h
File src/parsing/parser-base.h (right):

https://codereview.chromium.org/2370713003/diff/1/src/parsing/parser-base.h#n...
src/parsing/parser-base.h:388: DeclarationScope* scope() {
Should this be const?

And even better, can it return const DeclarationScope*?

https://codereview.chromium.org/2370713003/diff/1/src/parsing/preparser.cc
File src/parsing/preparser.cc (right):

https://codereview.chromium.org/2370713003/diff/1/src/parsing/preparser.cc#ne...
src/parsing/preparser.cc:97: if (is_strict(function_scope->language_mode())) {
Here we have already reset the function scope, and then we read data from it...
hmmmm.... in this case you don't clear language_mode, but it's quite a
surprising pattern.

[Toon Verwaest, 2016-09-26 12:56:59]

Addressed comments and rebased. Now resetting is done much later, close to where
the other resetting is done. They should be unified though. (We probably
shouldn't be allocating 2 function scopes even with temp zones)

[marja, 2016-09-26 13:06:10]

lgtm

[Toon Verwaest, 2016-09-26 13:11:14]

The CQ bit was checked by verwaest@chromium.org

[commit-bot: I haz the power, 2016-09-26 13:11:23]

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, 2016-09-26 13:41:08]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-26 13:41:28]

Description was changed from

==========
Preparse functions in the scope that was created when parsing of the function
was started

This reduces the number of scopes for lazily parsed top-level functions from 3
to 1

BUG=v8:5209
==========

to

==========
Preparse functions in the scope that was created when parsing of the function
was started

This reduces the number of scopes for lazily parsed top-level functions from 3
to 1

BUG=v8:5209

Committed: https://crrev.com/9618d095903c604a032b33792c068f4a6169503c
Cr-Commit-Position: refs/heads/master@{#39725}
==========

[commit-bot: I haz the power, 2016-09-26 13:41:29]

Patchset 2 (id:??) landed as
https://crrev.com/9618d095903c604a032b33792c068f4a6169503c
Cr-Commit-Position: refs/heads/master@{#39725}

[Michael Hablich, 2016-09-26 14:02:03]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/2365393002/ by hablich@chromium.org.

The reason for reverting is: Needed for
https://codereview.chromium.org/2373443003/.