Add flag to disable string externalization

Add flag to disable string externalization, allowing the compiler to rely on string class checks remaining valid across calls.

R=fschneider@google.com

Committed: https://github.com/dart-lang/sdk/commit/34e4107c0d4f73586ac59337c058c87377431243

[rmacnak, 2016-04-06 21:40:24]

Description was changed from

==========
.


.


.


stashing

BUG=
==========

to

==========
Add flag to disable string externalization, allowing the compiler to rely on
string class checks remaining valid across calls.
==========

[rmacnak, 2016-04-06 23:33:50]

rmacnak@google.com changed reviewers:
+ fschneider@google.com

[Florian Schneider, 2016-04-07 16:28:27]

Lgtm

[srdjan, 2016-04-07 16:47:35]

srdjan@google.com changed reviewers:
+ srdjan@google.com

[srdjan, 2016-04-07 16:47:36]

DBC

https://codereview.chromium.org/1859273002/diff/40001/runtime/vm/dart_api_imp...
File runtime/vm/dart_api_impl_test.cc (right):

https://codereview.chromium.org/1859273002/diff/40001/runtime/vm/dart_api_imp...
runtime/vm/dart_api_impl_test.cc:5579: FLAG_support_externalizable_strings =
true;
It seems that we are not that consistent, but many times we restore the old flag
value before existing the test, so that the local flag value does not escape the
test.

https://codereview.chromium.org/1859273002/diff/40001/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/1859273002/diff/40001/runtime/vm/object.cc#ne...
runtime/vm/object.cc:7819: bool Field::IsExternalizableCid(intptr_t cid) {
I wonder why we put this static method in Field?

[rmacnak, 2016-04-07 20:22:37]

https://chromiumcodereview.appspot.com/1859273002/diff/40001/runtime/vm/dart_...
File runtime/vm/dart_api_impl_test.cc (right):

https://chromiumcodereview.appspot.com/1859273002/diff/40001/runtime/vm/dart_...
runtime/vm/dart_api_impl_test.cc:5579: FLAG_support_externalizable_strings =
true;
On 2016/04/07 16:47:36, srdjan wrote:
> It seems that we are not that consistent, but many times we restore the old
flag
> value before existing the test, so that the local flag value does not escape
the
> test.

Added a restore for these changes.

https://chromiumcodereview.appspot.com/1859273002/diff/40001/runtime/vm/objec...
File runtime/vm/object.cc (right):

https://chromiumcodereview.appspot.com/1859273002/diff/40001/runtime/vm/objec...
runtime/vm/object.cc:7819: bool Field::IsExternalizableCid(intptr_t cid) {
On 2016/04/07 16:47:36, srdjan wrote:
> I wonder why we put this static method in Field?

Field guard logic uses it.

[rmacnak, 2016-04-07 20:24:48]

Description was changed from

==========
Add flag to disable string externalization, allowing the compiler to rely on
string class checks remaining valid across calls.
==========

to

==========
Add flag to disable string externalization, allowing the compiler to rely on
string class checks remaining valid across calls.

R=fschneider@google.com

Committed:
https://github.com/dart-lang/sdk/commit/34e4107c0d4f73586ac59337c058c87377431243
==========

[rmacnak, 2016-04-07 20:24:50]

Committed patchset #4 (id:60001) manually as
34e4107c0d4f73586ac59337c058c87377431243 (presubmit successful).