Make bin/pub script work when run from the repo.

Make bin/pub script work when run from the repo.

BUG=https://code.google.com/p/dart/issues/detail?id=10928
R=dgrove@google.com, nweiz@google.com

Committed: https://code.google.com/p/dart/source/detail?r=23438

[Bob Nystrom, 2013-05-29 17:32:07]

I haven't updated the Windows batch file to work yet. I can do that in a
separate patch.

[nweiz, 2013-05-29 17:57:00]

One question, otherwise LGTM.

https://codereview.chromium.org/15949005/diff/1/sdk/lib/_internal/pub/lib/src...
File sdk/lib/_internal/pub/lib/src/sdk.dart (right):

https://codereview.chromium.org/15949005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/sdk.dart:50: if (!fileExists(revisionPath)) return
new Version.parse("0.1.2+repo");
Under what circumstances would a version file not exist in the repo? Won't the
SDK be built whenever the packages directory is built?

[Bob Nystrom, 2013-05-29 19:45:35]

Dan, can you take a look at my change to bin/dart?

This helps running pub from the repo by letting it find other stuff in the SDK
relative to the Dart executable.

https://codereview.chromium.org/15949005/diff/1/sdk/lib/_internal/pub/lib/src...
File sdk/lib/_internal/pub/lib/src/sdk.dart (right):

https://codereview.chromium.org/15949005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/sdk.dart:50: if (!fileExists(revisionPath)) return
new Version.parse("0.1.2+repo");
On 2013/05/29 17:57:00, nweiz wrote:
> Under what circumstances would a version file not exist in the repo? Won't the
> SDK be built whenever the packages directory is built?

Oh, good point. We rely on the SDK being built anyway (to find the dart
executable, and the "packages" directory for pub) so we should be able to find
the version file in there too.

It turns out the problem here was that the dart binary being run was the one in
the root of the build directory, not in the built SDK directory. Changed that
script and this is no longer needed.

[dgrove, 2013-05-30 17:52:56]

lgtm

https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart
File sdk/bin/dart (right):

https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart#newcode19
sdk/bin/dart:19: BIN_DIR="$CUR_DIR"/../../out/$DART_CONFIGURATION/dart-sdk/bin
I think this will work. I talked with the VM team, and none of them sound like
they'd be impacted by this change.

[Bob Nystrom, 2013-05-30 19:36:56]

Committed patchset #2 manually as r23438 (presubmit successful).

[ricow1, 2013-06-03 07:21:58]

[+ahe,+kasperl]
This makes it impossible to run dart2js from sdk/bin unless you have build the
sdk!

[kasperl, 2013-06-03 07:25:39]

On 2013/06/03 07:21:58, ricow1 wrote:
> [+ahe,+kasperl]
> This makes it impossible to run dart2js from sdk/bin unless you have build the
> sdk!

That sounds bad. The whole point of this exercise was to make it easier to run
stuff from the repo, right?

[ahe, 2013-06-03 07:50:09]

I have previously asked that Rico, Martin, and me are involved in CLs that
change the build system. This allows us to save time by getting people involved
in the review who are aware of the big picture.

https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart
File sdk/bin/dart (right):

https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart#newcode19
sdk/bin/dart:19: BIN_DIR="$CUR_DIR"/../../out/$DART_CONFIGURATION/dart-sdk/bin
On 2013/05/30 17:52:56, dgrove wrote:
> I think this will work. I talked with the VM team, and none of them sound like
> they'd be impacted by this change.

This won't work. The original idea was as follows:

You run stuff from dart/sdk/bin to avoid building the SDK. 

You run stuff from PRODUCT_DIR/dart-sdk/bin if you want to test the SDK
(including snapshots).

The advantage to this setup is that there is no build step required to test
incremental changes to dart2js, I assume pub would benefit from this as well.

[dgrove, 2013-06-03 14:52:31]

On 2013/06/03 07:50:09, ahe wrote:
> I have previously asked that Rico, Martin, and me are involved in CLs that
> change the build system. This allows us to save time by getting people
involved
> in the review who are aware of the big picture.
> 
> https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart
> File sdk/bin/dart (right):
> 
> https://codereview.chromium.org/15949005/diff/4001/sdk/bin/dart#newcode19
> sdk/bin/dart:19: BIN_DIR="$CUR_DIR"/../../out/$DART_CONFIGURATION/dart-sdk/bin
> On 2013/05/30 17:52:56, dgrove wrote:
> > I think this will work. I talked with the VM team, and none of them sound
like
> > they'd be impacted by this change.
> 
> This won't work. The original idea was as follows:
> 
> You run stuff from dart/sdk/bin to avoid building the SDK. 
> 
> You run stuff from PRODUCT_DIR/dart-sdk/bin if you want to test the SDK
> (including snapshots).
> 
> The advantage to this setup is that there is no build step required to test
> incremental changes to dart2js, I assume pub would benefit from this as well.

Sorry about this - my mistake here. I didn't realize that anyone was running
without building the SDK. It appears to me that with this change, you could
still test incremental changes in dart2js without rebuilding. What am I missing?

[Bob Nystrom, 2013-06-03 15:25:21]

On 2013/06/03 07:50:09, ahe wrote:
> I have previously asked that Rico, Martin, and me are involved in CLs that
> change the build system.

Sorry, this patch was a shell script in sdk/ so I didn't realize this was build
related. The initial version of this patch didn't touch the dart2js shell
script. The pub shell script only had Dan in its history, so I added him to the
patch and Kasper.

> You run stuff from dart/sdk/bin to avoid building the SDK. 

Is the goal here to avoid *ever* building the SDK? I thought the intent was just
to not have to build the SDK *every time you make a change to dart2js*. My
intent with this patch was that it would run dart2js directly from the repo. It
just runs it on the Dart VM binary copied into <out>/dart-sdk/dart instead of
<out>/dart.

I thought the only reason we even had a Dart binary at <out>/dart was so that
the VM guys didn't have to think about the SDK. Does the dart2js team also not
build the SDK?

> The advantage to this setup is that there is no build step required to test
> incremental changes to dart2js, I assume pub would benefit from this as well.

Yes, that's the exact intent of this change. I'm not very familiar with these
scripts, but I thought this change did that. What did I miss?