1484948 - Parse dynamic module import syntax

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jon Coppeard (:jonco)]

Currently any use of an |import(specifier)| expression in scripts is a SyntaxError.  In classic scripts, any use of |import| at all is an error and in module scripts it is an error because it's not a valid import statement.

As a step towards implementing dynamic import, this bug is to make the engine parse this syntax but throw an error when it is encountered.  This won't change observable behaviour except:

 - probably the type of error thrown will be different
 - Reflect.parse will succeed for this syntax

Comment 1

[Jon Coppeard (:jonco)]

Attachment: bug1484948-parse-dynamic-import

Patch to parse dynamic import syntax.

This adds a CallImport parse node and makes the bytecode emitter throw when it encounters it.  I added tests to check we can parse this.

I had to update the wpt test expectations because the dynamic import tests now fail in a slightly different way.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: bug1484948-parse-dynamic-import-2

Update to previous patch to make this throw a syntax error rather than an internal error until dynamic import is implemented.

Comment 3

[Jason Orendorff [:jorendorff]]

Comment on attachment 9002770 [details] [diff] [review]
bug1484948-parse-dynamic-import

Review of attachment 9002770 [details] [diff] [review]:
-----------------------------------------------------------------

I'm sorry for the slow review here. Looks good.

Comment 4

[Jason Orendorff [:jorendorff]]

Comment on attachment 9006554 [details] [diff] [review]
bug1484948-parse-dynamic-import-2

Review of attachment 9006554 [details] [diff] [review]:
-----------------------------------------------------------------

That's better. Thanks.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/d1b2141b1c45
Parse dynamic module import syntax but throw SyntaxError if used r=jorendorff

Comment 6

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/d1b2141b1c45

Comment 7

[Ryan VanderMeulen [:RyanVM]]

This was reverted for Fx64 in bug 1503009. It remains on Fx65+.