gen_snapshot should be in the SDK

[jmesserly]

If we want developers to have access to this, it should be included in the SDK.

I wanted to try using it for one of our packages, but I can't add an automated step because you would need to have a Dart source tree checkout.

[dgrove]

Here's a CL that I put together to address this, but it can't be checked in until there are tests for gen_snapshot: https://codereview.chromium.org/11416255/

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Set owner to @peter-ahe-google.
Marked this as being blocked by #7020.

[peter-ahe-google]

cc @iposva-google.

[peter-ahe-google]

Ivan, please set a milestone that you feel comfortable with.

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Removed this from the M2 milestone.

[jmesserly]

Marked this as blocking #7947.

[jmesserly]

Marked this as blocking #7948.

[iposva-google]

Added this to the Later milestone.

[devoncarew]

Would it be possible for the stand-alone VM to create the snapshot itself? I imagine that gen_snapshot shares a lot of the same source with the VM. If the VM could create a snapshot (via something like --gen_snapshot), we'd save ~4.5 MB in the SDK and the user would have one less tool to have to learn.

[jmesserly]

+1 on having the VM just do this.
but in the meantime, even gen_snapshot would be super useful

In web_ui our tool has >300ms startup time just from Dart VM parsing and loading files. Snapshots could help this tremendously. Plus, I think this is a great chance to show off how useful snapshots can be.

[peter-ahe-google]

You don't need gen_snapshot in the SDK to start creating snapshots. Just build the tool yourself and call it.

[dgrove]

I don't understand. It isn't viable to get people building dart outside the repo to build the entire source (they have to get the machines set up to build chromium, etc). If we want gen_snapshot (and it appears to be very important important), we need to figure out how to get it into the SDK.

Can we get some clear criteria for what it would take to make this happen?

[dgrove]

I don't understand. It isn't viable to get people building dart outside the repo to build the entire source (they have to get the machines set up to build chromium, etc). If we want gen_snapshot (and it appears to be very important important), we need to figure out how to get it into the SDK.

Can we get some clear criteria for what it would take to make this happen?

[peter-ahe-google]

I'm saying that issue #7947 is not blocked on this issue. I'm not saying that is a convenient solution, or that it is a viable long term solution. I'm not saying that we shouldn't fix this bug.

[jmesserly]

Agree Peter with respect to that particular issue.
But not everyone using web_ui uses the Dart Editor.

I can't tell users of web_ui that they need a C++ compiler and build system (meaning they need to buy Visual Studio if on Windows...), a Dart SVN checkout, Chromium build tools, and Python, just to make Dart program startup fast...

[jmesserly]

(I worry people will get the perception that web_ui and/or Dart VM is slow to startup, which is the opposite of our design goal for the language)

[peter-ahe-google]

John, are you worried about startup times of a tool, or what the tool generates? Are you worried about startup performance of browser apps?

I'm not sure gen_snapshot fits the bill for all these situations, so I'd like to understand exactly what problem you have at present.