1541433 - Add a static analysis that detects Promises that are dropped on the floor

Status: NEW

(Developer Infrastructure :: Source Code Analysis, task, P3)

Description

[(no longer active)]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1498102#c54 and the resulting fix (https://hg.mozilla.org/integration/autoland/rev/3236fd896ae0).

The interesting pattern to detect here is when we have:

void f() {
  RefPtr<Promise> promise = foo();

  // promise won't escape
}

We should statically verify that the promise is either passed to something (e.g. returned to the caller or passed to another function) or a method that adds a rejection handler to it is called on it, like AppendNativeHandler(), Then(), etc.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:sylvestre, could you have a look please?