[modules] Detect and throw exceptions for cyclic dependencies

[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569
Committed: https://crrev.com/b48eb56905e7fb3f14d9f54adb4853e01fdacc4e
Cr-Commit-Position: refs/heads/master@{#39743}

[adamk, 2016-09-23 23:53:20]

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

[commit-bot: I haz the power, 2016-09-23 23:53:30]

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

[adamk, 2016-09-23 23:56:20]

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

[commit-bot: I haz the power, 2016-09-23 23:56:30]

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

[adamk, 2016-09-23 23:58:40]

Description was changed from

==========
[modules] Detect and throw exceptions for cyclic dependencies

BUG=v8:1569
==========

to

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

BUG=v8:1569
==========

[adamk, 2016-09-23 23:59:45]

Description was changed from

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

BUG=v8:1569
==========

to

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569
==========

[adamk, 2016-09-24 00:04:07]

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

[adamk, 2016-09-24 00:04:07]

This is ready for initial review, even if it's not quite done.

[commit-bot: I haz the power, 2016-09-24 00:29:23]

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

[commit-bot: I haz the power, 2016-09-24 00:29:24]

Dry run: This issue passed the CQ dry run.

[adamk, 2016-09-26 19:01:38]

Okay, this is ready for review again

[neis, 2016-09-26 21:06:28]

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h#newcode7953
src/objects.h:7953: 
s/Returns/Get/ for consistency

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h#newcode7958
src/objects.h:7958: inline uint32_t Hash() const;
s/code //

[adamk, 2016-09-26 21:20:47]

Handled review comments, clarified unordered_map usage, added a more complicated
cyclic test. PTAL.

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h#newcode7953
src/objects.h:7953: 
On 2016/09/26 21:06:28, neis wrote:
> s/Returns/Get/ for consistency

Done.

https://codereview.chromium.org/2367623004/diff/20001/src/objects.h#newcode7958
src/objects.h:7958: inline uint32_t Hash() const;
On 2016/09/26 21:06:28, neis wrote:
> s/code //

Done.

[neis, 2016-09-26 22:13:40]

The CQ bit was checked by neis@chromium.org

[neis, 2016-09-26 22:13:40]

lgtm

[commit-bot: I haz the power, 2016-09-26 22:13:54]

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 22:42:25]

Description was changed from

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569
==========

to

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569
==========

[commit-bot: I haz the power, 2016-09-26 22:42:25]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-09-26 22:42:53]

Description was changed from

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569
==========

to

==========
[modules] Detect and throw exceptions for cyclic dependencies

Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.

This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.

Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.

BUG=v8:1569

Committed: https://crrev.com/b48eb56905e7fb3f14d9f54adb4853e01fdacc4e
Cr-Commit-Position: refs/heads/master@{#39743}
==========

[commit-bot: I haz the power, 2016-09-26 22:42:54]

Patchset 4 (id:??) landed as
https://crrev.com/b48eb56905e7fb3f14d9f54adb4853e01fdacc4e
Cr-Commit-Position: refs/heads/master@{#39743}