add tool to verify dependency information

add tool to verify dependency information

the tools verifies that all elements are reachable from main

BUG=
R=sigmund@google.com

Committed: https://github.com/dart-lang/dart2js_info/commit/11c920c72606869c528f27e7eb05fb7911dc724c

[Harry Terkelsen, 2015-10-14 23:14:37]

het@google.com changed reviewers:
+ sigmund@google.com

[Siggi Cherem (dart-lang), 2015-10-14 23:37:02]

lgtm

https://codereview.chromium.org/1406803003/diff/20001/CHANGELOG.md
File CHANGELOG.md (right):

https://codereview.chromium.org/1406803003/diff/20001/CHANGELOG.md#newcode3
CHANGELOG.md:3: ## 0.1.1
FYI up to you if you want to publish right away or later - if you prefer to
publish later, let's use 0.1.1-dev for now

https://codereview.chromium.org/1406803003/diff/20001/README.md
File README.md (right):

https://codereview.chromium.org/1406803003/diff/20001/README.md#newcode192
README.md:192: bootstrapping code and lazy static initializers are missing.
thanks for all the typo fixes!

https://codereview.chromium.org/1406803003/diff/20001/README.md#newcode279
README.md:279: output anything and will return with exitcode 0. Otherwise, the
tool will
sometimes not seeing any results feels like a mystery. How about we print a
single line saying "everything appears reachable" or something similar?

https://codereview.chromium.org/1406803003/diff/20001/lib/info.dart
File lib/info.dart (right):

https://codereview.chromium.org/1406803003/diff/20001/lib/info.dart#newcode153
lib/info.dart:153: factory AllInfo.fromJson(Map json) => new
_ParseHelper().parseAll(json);
since this is a breaking change, we might need to change the version to 0.2.0.

FWIW - I was hoping we remove it entirely once we split the serialization to be
outside of the info classes
(https://github.com/dart-lang/dart2js_info/issues/4), then all to/from json is
detached and we can support different encodings without changing the info API.

[Harry Terkelsen, 2015-10-15 00:13:55]

https://codereview.chromium.org/1406803003/diff/20001/CHANGELOG.md
File CHANGELOG.md (right):

https://codereview.chromium.org/1406803003/diff/20001/CHANGELOG.md#newcode3
CHANGELOG.md:3: ## 0.1.1
On 2015/10/14 23:37:02, Siggi Cherem (dart-lang) wrote:
> FYI up to you if you want to publish right away or later - if you prefer to
> publish later, let's use 0.1.1-dev for now

let's do 0.2.0-dev for now and release when we have a proper Codec for Info

https://codereview.chromium.org/1406803003/diff/20001/README.md
File README.md (right):

https://codereview.chromium.org/1406803003/diff/20001/README.md#newcode192
README.md:192: bootstrapping code and lazy static initializers are missing.
On 2015/10/14 23:37:02, Siggi Cherem (dart-lang) wrote:
> thanks for all the typo fixes!

no problem :)

https://codereview.chromium.org/1406803003/diff/20001/README.md#newcode279
README.md:279: output anything and will return with exitcode 0. Otherwise, the
tool will
On 2015/10/14 23:37:02, Siggi Cherem (dart-lang) wrote:
> sometimes not seeing any results feels like a mystery. How about we print a
> single line saying "everything appears reachable" or something similar?

Done.

https://codereview.chromium.org/1406803003/diff/20001/lib/info.dart
File lib/info.dart (right):

https://codereview.chromium.org/1406803003/diff/20001/lib/info.dart#newcode153
lib/info.dart:153: factory AllInfo.fromJson(Map json) => new
_ParseHelper().parseAll(json);
On 2015/10/14 23:37:02, Siggi Cherem (dart-lang) wrote:
> since this is a breaking change, we might need to change the version to 0.2.0.
> 
> FWIW - I was hoping we remove it entirely once we split the serialization to
be
> outside of the info classes
> (https://github.com/dart-lang/dart2js_info/issues/4), then all to/from json is
> detached and we can support different encodings without changing the info API.

I added a TODO for this. Let's go with 0.2.0-dev and then roll when we have an
InfoCodec

[Harry Terkelsen, 2015-10-15 00:15:07]

Committed patchset #3 (id:40001) manually as
11c920c72606869c528f27e7eb05fb7911dc724c (presubmit successful).