1126361 - Default value in destructuring cannot access to function argument.

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Tooru Fujisawa [:arai]]

Currently identifierName in default value in destructuring is not linked to definition node, and it's emitted as JSOP_GETNAME/JSOP_SETNAME, so it cannot access to function argument:

  js> ((a, [b=a]) => b)(1, [])
  typein:1:5 ReferenceError: a is not defined

It should be 1.

Comment 1

[Tooru Fujisawa [:arai]]

try is running: https://treeherder.mozilla.org/#/jobs?repo=try&revision=8c2ed4a0c781

Comment 2

[Tooru Fujisawa [:arai]]

Attachment: Lookup definition node for identifierName in default value in destructuring.

Set `pc->inDeclDestructuring` to false for RHS of assignment expression, so `noteNameUse` will be called in identifierName for default values.

Green on try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=8c2ed4a0c781

With this fix, I can write remaining part of the patch in bug 1018628, yay :)

Comment 3

[Jason Orendorff [:jorendorff]]

Comment on attachment 8555409 [details] [diff] [review]
Lookup definition node for identifierName in default value in destructuring.

Review of attachment 8555409 [details] [diff] [review]:
-----------------------------------------------------------------

Thank you. Sorry for the slow review here!

::: js/src/frontend/Parser.cpp
@@ +6297,2 @@
>      Node rhs = assignExpr();
> +    pc->inDeclDestructuring = saved;

Good. I ran into the same thing in bug 1051760. I wish the front end wasn't so precarious. :-\

Comment 4

[Tooru Fujisawa [:arai]]

Thank you for reviewing! :D
https://hg.mozilla.org/integration/mozilla-inbound/rev/6b0631da5300

Comment 5

[Tooru Fujisawa [:arai]]

bug number in the commit message was wrong, sorry for my mistake!

https://hg.mozilla.org/mozilla-central/rev/6b0631da5300