Add native extensions to the Dart shell, on the linux platform.

Add native extensions to the Dart shell, on the linux platform.


BUG=
TEST=standalone/TestExtensionTest

Committed: https://code.google.com/p/dart/source/detail?r=4529

[Bill Hesse, 2012-02-22 16:37:26]

All comments addressed.  Symbolic links work for the .so files.

[Søren Gjesse, 2012-02-23 07:47:27]

lgtm

[Mads Ager (google), 2012-02-23 09:26:56]

LGTM

We need to get in a position where this is tested on the buildbots.

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/dartutils.cc
File runtime/bin/dartutils.cc (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/dartutils....
runtime/bin/dartutils.cc:13: const char* DartUtils::kDartExtensionScheme =
"dartext:";
Should we make this "dart-ext:"?

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/extensions.h
File runtime/bin/extensions.h (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/extensions...
runtime/bin/extensions.h:13: // TODO(whesse): Make loading extensions lazy, so
dynamic library is loaded
I'm not sure about this one. It could be an advantage as well to get all the
libraries loaded up front so you don't get load overhead at some random point.

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/extensions...
File runtime/bin/extensions_linux.cc (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/extensions...
runtime/bin/extensions_linux.cc:8: #include "bin/file.h"
Is anything from file used in this file?

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/extensions...
runtime/bin/extensions_linux.cc:15: // The current implementation allows names
only, not paths, and
I would get rid of the fixed-size buffer here and just use the computed length
and dynamic allocation.

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/test_exten...
File runtime/bin/test_extension_linux.cc (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/test_exten...
runtime/bin/test_extension_linux.cc:13: extern "C" EXPORT_SYMBOL Dart_Handle
test_extension_Init(Dart_Handle library) {
Maybe we should use lower-case 'init' as well?

https://chromiumcodereview.appspot.com/9430051/diff/16/tests/standalone/src/t...
File tests/standalone/src/test_extension.dart (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/tests/standalone/src/t...
tests/standalone/src/test_extension.dart:16: static int ifNull(a, b) native
'Cat_IfNull';
Could you add a comment to this? I don't understand why this is called ifNull?

https://chromiumcodereview.appspot.com/9430051/diff/16/tests/standalone/stand...
File tests/standalone/standalone.status (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/tests/standalone/stand...
tests/standalone/standalone.status:18: TestExtensionTest: Fail  # Requires
test_extension library in current directory.
The test is disabled everywhere at this point. This is temporary, right? Could
you add a bug report number to track the testing of extensions?

[Søren Gjesse, 2012-02-23 10:20:29]

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/test_exten...
File runtime/bin/test_extension_linux.cc (right):

https://chromiumcodereview.appspot.com/9430051/diff/16/runtime/bin/test_exten...
runtime/bin/test_extension_linux.cc:13: extern "C" EXPORT_SYMBOL Dart_Handle
test_extension_Init(Dart_Handle library) {
On 2012/02/23 09:26:56, Mads Ager wrote:
> Maybe we should use lower-case 'init' as well? 

It was originally "init" and I suggested to change it to "Init" to somehow
conform to the Dart API "Dart_XxxYyy". Alternatively "test_extension" could be
"TestExtension" making it "TestExtension_Init". I have no strong opinion here.
Whatever we do extension writers will use "my_extension" or "MyExtension" or
"My_Extension" or "myExtension" or ...