Commit Graph

2 Commits

Author SHA1 Message Date
Benedikt Meurer
93043d6482 [async] Add CallSite#getPromiseIndex() builtin.
In order for Error.prepareStackTrace() to be able to reconstruct the
same stack frame that the internal mechanism can, we need to also
expose the index for the Promise.all() builtin. The newly added
CallSite#getPromiseIndex() does exactly that.

Bug: v8:7522
Change-Id: I904a4c1005f539536a71926ea1da38b31e2a2e8a
Reviewed-on: https://chromium-review.googlesource.com/c/1304293
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57055}
2018-10-29 08:47:59 +00:00
Benedikt Meurer
6f39ab8911 [async] Add Promise.all() support to --async-stack-traces.
This adds support for Promise.all() to --async-stack-traces (also at
zero cost, since we can derive the relevant information from the resolve
element closure and context). In case of `Promise.all(a)` the stack
trace even tells you which element of `a` is responsible, for example

```js
async function fine() {}
async function thrower() { await fine(); throw new Error(); }
async function test() { await Promise.all([fine(), thrower()]); }
```

will generate the following stack trace

```
Error
    at thrower (something.js:1:9)
    at async Promise.all (index 1)
    at async test (something.js:3:3)
```

so it not only shows the async Promise.all() frames, but even tells the
user exactly that the second element of `[fine(), thrower()]` is the
relevant one.

Bug: v8:7522
Change-Id: I279a845888e06053cf0e3c9338ab71caabaabf45
Reviewed-on: https://chromium-review.googlesource.com/c/1299248
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57023}
2018-10-26 09:53:50 +00:00