Starting work on full GN build

Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime'
target for x64, ia32, arm, arm64, mips, and the
simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested
on Mac or Windows. That work and more cleanup of
chrome boilerplate will come in follow-up CLs.

R=johnmccutchan@google.com

Committed: https://github.com/dart-lang/sdk/commit/7e1b7e54d735c53af048174f31a49153c678b553

[zra, 2016-09-21 18:28:27]

Description was changed from

==========
Starting work on full GN build
==========

to

==========
Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime' target for x64, ia32, arm,
arm64, mips, and the simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested on Mac or Windows. That
work and more cleanup of chrome boilerplate will come in follow-up CLs.
==========

[zra, 2016-09-21 18:28:51]

Description was changed from

==========
Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime' target for x64, ia32, arm,
arm64, mips, and the simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested on Mac or Windows. That
work and more cleanup of chrome boilerplate will come in follow-up CLs.
==========

to

==========
Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime'
target for x64, ia32, arm, arm64, mips, and the
simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested
on Mac or Windows. That work and more cleanup of
chrome boilerplate will come in follow-up CLs.
==========

[zra, 2016-09-21 18:32:24]

zra@google.com changed reviewers:
+ johnmccutchan@google.com

[zra, 2016-09-21 18:32:25]

We can probably start reviewing this. There's some work by Fuchsia folks that
needs to be merged into //runtime/bin/BUILD.gn, and I need to make sure these
changes don't break Flutter, but if there are any fixes needed they should be
small.

[Cutch, 2016-09-21 23:26:27]

https://codereview.chromium.org/2350583002/diff/40001/runtime/BUILD.gn
File runtime/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/BUILD.gn#newcod...
runtime/BUILD.gn:183: static_library("libdart") {
"libdart" and "libdart_precompiled_runtime" can be put behind a template to
avoid duplication.

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn
File runtime/bin/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:254: static_library("libdart_nosnapshot") {
same comment here about a template to avoid the duplicated code.

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:481: defines = [
just for consistency here:

defines += ...

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:640: executable("dart_precompiled_runtime") {
This is identical to the executable "dart' above. You probably meant to link
against libdart_precompiled_runtime instead of libdart in this target. Same
comment here as other "_precompiled_runtime" variants -- we should have a
template that generates both executable rules.

https://codereview.chromium.org/2350583002/diff/40001/runtime/observatory/BUI...
File runtime/observatory/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/observatory/BUI...
runtime/observatory/BUILD.gn:159: assert(defined(invoker.inner_namespace), "Need
inner_namespace in $target_name")
line length

[zra, 2016-09-22 06:08:17]

https://codereview.chromium.org/2350583002/diff/40001/runtime/BUILD.gn
File runtime/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/BUILD.gn#newcod...
runtime/BUILD.gn:183: static_library("libdart") {
On 2016/09/21 23:26:27, Cutch wrote:
> "libdart" and "libdart_precompiled_runtime" can be put behind a template to
> avoid duplication.

Done.

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn
File runtime/bin/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:254: static_library("libdart_nosnapshot") {
On 2016/09/21 23:26:27, Cutch wrote:
> same comment here about a template to avoid the duplicated code.

Done.

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:481: defines = [
On 2016/09/21 23:26:27, Cutch wrote:
> just for consistency here:
> 
> defines += ...

Done.

https://codereview.chromium.org/2350583002/diff/40001/runtime/bin/BUILD.gn#ne...
runtime/bin/BUILD.gn:640: executable("dart_precompiled_runtime") {
On 2016/09/21 23:26:27, Cutch wrote:
> This is identical to the executable "dart' above. You probably meant to link
> against libdart_precompiled_runtime instead of libdart in this target. Same
> comment here as other "_precompiled_runtime" variants -- we should have a
> template that generates both executable rules.

Done.

https://codereview.chromium.org/2350583002/diff/40001/runtime/observatory/BUI...
File runtime/observatory/BUILD.gn (right):

https://codereview.chromium.org/2350583002/diff/40001/runtime/observatory/BUI...
runtime/observatory/BUILD.gn:159: assert(defined(invoker.inner_namespace), "Need
inner_namespace in $target_name")
On 2016/09/21 23:26:27, Cutch wrote:
> line length

Done.

[Cutch, 2016-09-22 15:51:16]

lgtm

[zra, 2016-09-23 14:47:39]

Description was changed from

==========
Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime'
target for x64, ia32, arm, arm64, mips, and the
simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested
on Mac or Windows. That work and more cleanup of
chrome boilerplate will come in follow-up CLs.
==========

to

==========
Starting work on full GN build

This change:
- Sucks in gn binaries
- Sucks in a version of llvm that the GN build likes
- Adds tools/gn.py to invoke gn
- Adds a root BUILD.gn and .gn file
- Removes chrome boilerplate we don't need
- etc.

This lets us do a standalone build of the 'runtime'
target for x64, ia32, arm, arm64, mips, and the
simulators on Linux, and arm and arm64 on Android.

It does not include tcmalloc, and hasn't been tested
on Mac or Windows. That work and more cleanup of
chrome boilerplate will come in follow-up CLs.

R=johnmccutchan@google.com

Committed:
https://github.com/dart-lang/sdk/commit/7e1b7e54d735c53af048174f31a49153c678b553
==========

[zra, 2016-09-23 14:47:41]

Committed patchset #6 (id:100001) manually as
7e1b7e54d735c53af048174f31a49153c678b553 (presubmit successful).