Make file system watcher compile on Mac OS 106, and add a runtime-call to test if the system suppor…

Make file system watcher compile on Mac OS 106, and add a runtime-call to test if the system supports the feature.

BUG=
R=kustermann@google.com, sgjesse@google.com

Committed: https://code.google.com/p/dart/source/detail?r=27064

[Søren Gjesse, 2013-09-03 15:15:50]

lgtm

[kustermann, 2013-09-03 15:18:58]

LGTM to get the bot green. But I think soeren should also take a closer look at
it.

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_patch.dart
File runtime/bin/file_patch.dart (right):

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_patch.dart#n...
runtime/bin/file_patch.dart:50: /* patch */ static bool get isSupported =>
_FileSystemWatcherImpl.isSupported;
Wouldn't it make sense to cache the 'isSupported' value.
Otherwise we always call into c++ and do a syscall.

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_system_watch...
File runtime/bin/file_system_watcher_macos.cc (right):

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_system_watch...
runtime/bin/file_system_watcher_macos.cc:216: Gestalt(gestaltSystemVersion,
&version);
Seems like 'Gestalt' is deprecated / will be removed:

http://stackoverflow.com/questions/11072804/mac-os-x-10-8-replacement-for-ges...

Building on 10.8 will emit the deprecation warnings (I don't know if they're
considered fatal or not) -- i.e. this could break a 10.8 build?

This returns an OSError. We may not want to ignore it.


"Never infer the availability of hardware or software features from the value
that the Gestalt function returns when you pass it the gestaltSystemVersion
selector.":
https://developer.apple.com/library/mac/documentation/Carbon/reference/Gestal...

[Anders Johnsen, 2013-09-03 15:32:56]

PTAL

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_patch.dart
File runtime/bin/file_patch.dart (right):

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_patch.dart#n...
runtime/bin/file_patch.dart:50: /* patch */ static bool get isSupported =>
_FileSystemWatcherImpl.isSupported;
On 2013/09/03 15:18:58, kustermann wrote:
> Wouldn't it make sense to cache the 'isSupported' value.
> Otherwise we always call into c++ and do a syscall.

As this is not performance critical, I'll not cache it, but you are right, it
could be done here.

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_system_watch...
File runtime/bin/file_system_watcher_macos.cc (right):

https://codereview.chromium.org/23483030/diff/1/runtime/bin/file_system_watch...
runtime/bin/file_system_watcher_macos.cc:216: Gestalt(gestaltSystemVersion,
&version);
On 2013/09/03 15:18:58, kustermann wrote:
> Seems like 'Gestalt' is deprecated / will be removed:
> 
>
http://stackoverflow.com/questions/11072804/mac-os-x-10-8-replacement-for-ges...
> 
> Building on 10.8 will emit the deprecation warnings (I don't know if they're
> considered fatal or not) -- i.e. this could break a 10.8 build?
> 
> This returns an OSError. We may not want to ignore it.
> 
> 
> "Never infer the availability of hardware or software features from the value
> that the Gestalt function returns when you pass it the gestaltSystemVersion
> selector.":
>
https://developer.apple.com/library/mac/documentation/Carbon/reference/Gestal...

Nicely spotted, changed.

[kustermann, 2013-09-03 15:39:42]

LGTM

[Anders Johnsen, 2013-09-03 15:42:41]

Committed patchset #3 manually as r27064 (presubmit successful).