423706 - Parser generates ListExpr in many cases when it shouldn't

Status: RESOLVED FIXED

(Tamarin Graveyard :: Self-hosting compiler (ESC), defect)

Description

[Lars T Hansen]

This returns false as it should:
  delete Boolean.prototype

This returns true:
  delete (Boolean.prototype)

Comment 1

[Lars T Hansen]

This is an instance of a general parser bug wherein the parser returns Ast::ListExpr nodes far too often.  The grammar production in question is ListExpression, but this production is overloaded to be used both on function parameters and on comma expressions.  The latter cases should (probably) be rewritten to use a CommaExpression production which produces a simple expression if there's only one and Ast::Comma(x,y) otherwise.  Note, this may cause some wrinkles in cogen which depends on Ast::ListExpr in a couple of places.

Comment 2

[Lars T Hansen]

Also a problem for "typeof (x)" for the same reason.

Comment 3

[Lars T Hansen]

Attachment: Patch

Removes ListExpr from ESC, substitutes CommaExpr and cleans up some hacks that were necessary to support ListExpr previously.

Comment 4

[Jeff Dyer]

Comment on attachment 311190 [details] [diff] [review]
Patch

This matches my updated grammar with one difference being is renamed parenListExpression to parenExpression rather than parenCommaExpression

Comment 5

[Lars T Hansen]

Changeset 485:ca35d6ab0083

Comment 6

[Lars T Hansen]

Was never pushed, new changeset 492:9068d6de7549