1414684 - [jsdbg2] Debugger.Environment.prototype.callee should not return undefined for inner functions

Status: RESOLVED DUPLICATE of bug 1663847

(Core :: JavaScript Engine, enhancement, P3)

Description

[Jim Blandy :jimb]

Debugger.Environment.prototype.callee returns undefined on "declarative" environments if the referent environment is "hollow" (i.e., was optimized out). This is surprising to users, who expect environments for function calls to have functions associated with them.

This behavior was introduced deliberately in bug 1163520. In the implementation, fetching the callee of a hollow environment returns an internal function object, which should never be exposed to content.

Instead of returning undefined, the callee accessor should probably return an object like { optimizedOut: true }, like D.E.p.getVariable.

See also bug 1414683.

Comment 1

[Jan de Mooij [:jandem]]

I'm fixing this in 1663847. I'll post before and after screenshots of the debugger when I break on the console.log here:

    function outer(a, b) {
      function inner(x, y) {
        console.log("Hello");
        return x + y;
      }
      return inner(a + 4, b + 6);
    }
    outer(1, 3);

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Before (inner function reported as Block)

Comment 3

[Jan de Mooij [:jandem]]

Attachment: After (inner function reported properly)