940086 - [reflect.jsm] FunctionDeclaration nodes' locations start on the identifier, not the "function" keyword

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

If you parse

  function foo() {
    doStuff();
  }

with location information, the FunctionDeclaration node reports its start column as 9, when it should be 0.

-------------------

In devtools, we want to use Reflect.jsm to parse some text, and then find the sub-slice of the text that corresponds to specific function declarations so we can eval that sub-slice of text to provide simple live editing or something similar to Emacs' eval-defun[0]. We can't do this if we can't rely on the locations reported by Reflect.jsm to be correct.

[0] http://www.gnu.org/software/emacs/manual/html_node/emacs/Lisp-Eval.html

Comment 1

[Jim Blandy :jimb]

I think those coordinates are also used for lazy compilation; but it seems like there's no reason lazy compilation needs to change the function node's coordinates, when it could just as well fetch what it needs from a more appropriate parse node.