Write the magic number 0xf5f5dcdc into a script snapshot file and use this to distinguish whether a…

Write the magic number 0xf5f5dcdc into a script snapshot file and use this to distinguish whether a script snapshot or a regular script file is being passed on the command line (removed the --use-script-snapshot option).
Committed: https://code.google.com/p/dart/source/detail?r=20339

[Ivan Posva, 2013-03-20 06:18:00]

https://codereview.chromium.org/12438033/diff/9001/runtime/bin/dartutils.cc
File runtime/bin/dartutils.cc (right):

https://codereview.chromium.org/12438033/diff/9001/runtime/bin/dartutils.cc#n...
runtime/bin/dartutils.cc:372: Dart_Handle script_path =
DartUtils::FilePathFromUri(resolved_script_uri,
Does this mean that script snapshots can be loaded from URIs recognized by the
standalone VM?

https://codereview.chromium.org/12438033/diff/9001/runtime/bin/dartutils.cc#n...
runtime/bin/dartutils.cc:388: return Dart_LoadScriptFromSnapshot(text_buffer);
I am wondering whether we should be passing the length of the buffer as well to
make sure it matches the expected length.

https://codereview.chromium.org/12438033/diff/9001/runtime/bin/main.cc
File runtime/bin/main.cc (right):

https://codereview.chromium.org/12438033/diff/9001/runtime/bin/main.cc#newcod...
runtime/bin/main.cc:459: Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
Isn't this library also part of the script snapshot? Will it be loaded twice in
this case? Once here and once from the script snapshot, further below when we
determine to be loading a script snapshot.

I understand that this was already happening before, but I would like to make
sure this is correct.

[ahe, 2013-03-20 06:59:28]

Dart2js changes, LGTM

https://chromiumcodereview.appspot.com/12438033/diff/9001/sdk/bin/dart2js
File sdk/bin/dart2js (left):

https://chromiumcodereview.appspot.com/12438033/diff/9001/sdk/bin/dart2js#old...
sdk/bin/dart2js:44: echo Using snapshot "$SNAPSHOT" 1>&2
Could you retain this for now?

[ahe, 2013-03-20 09:23:14]

+Alexander who is working on fixing a bug in dart2js.bat.

[siva, 2013-03-20 20:57:20]

https://chromiumcodereview.appspot.com/12438033/diff/9001/runtime/bin/dartuti...
File runtime/bin/dartutils.cc (right):

https://chromiumcodereview.appspot.com/12438033/diff/9001/runtime/bin/dartuti...
runtime/bin/dartutils.cc:372: Dart_Handle script_path =
DartUtils::FilePathFromUri(resolved_script_uri,
Yes, that was the intent. I wanted to make the code as uniform as possible for
both the regular script and script snapshot case.

On 2013/03/20 06:18:00, Ivan Posva wrote:
> Does this mean that script snapshots can be loaded from URIs recognized by the
> standalone VM?

https://chromiumcodereview.appspot.com/12438033/diff/9001/runtime/bin/dartuti...
runtime/bin/dartutils.cc:388: return Dart_LoadScriptFromSnapshot(text_buffer);
On 2013/03/20 06:18:00, Ivan Posva wrote:
> I am wondering whether we should be passing the length of the buffer as well
to
> make sure it matches the expected length.

Done.

https://chromiumcodereview.appspot.com/12438033/diff/9001/runtime/bin/main.cc
File runtime/bin/main.cc (right):

https://chromiumcodereview.appspot.com/12438033/diff/9001/runtime/bin/main.cc...
runtime/bin/main.cc:459: Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
This library is part of the core snapshot, It will not end up in the script
snapshot.
We should find it already here when we lookup. I will add a comment to that
effect.

On 2013/03/20 06:18:00, Ivan Posva wrote:
> Isn't this library also part of the script snapshot? Will it be loaded twice
in
> this case? Once here and once from the script snapshot, further below when we
> determine to be loading a script snapshot.
> 
> I understand that this was already happening before, but I would like to make
> sure this is correct.

https://chromiumcodereview.appspot.com/12438033/diff/9001/sdk/bin/dart2js
File sdk/bin/dart2js (left):

https://chromiumcodereview.appspot.com/12438033/diff/9001/sdk/bin/dart2js#old...
sdk/bin/dart2js:44: echo Using snapshot "$SNAPSHOT" 1>&2
On 2013/03/20 06:59:28, ahe wrote:
> Could you retain this for now?

Done.

[Ivan Posva, 2013-03-21 00:42:00]

LGTM -ip

[siva, 2013-03-21 00:55:17]

Anton, need to co-ordinate tomorrow regarding changing
Dart_LoadScriptFromSnapshot to take an additional argument buffer_len.

[siva, 2013-03-21 18:47:55]

Committed patchset #4 manually as r20339 (presubmit successful).