Add convenience getter to extract the location of an AST node.

Add convenience getter to extract the location of an AST node.

TreeNode.location is a getter for use in diagnostics and debugging.

It uses parent pointers to find the enclosing file URI and line ending
table of the node. If the node has no offset stored, it will use that
of the first enclosing parent that has an offset.

BUG=
R=ahe@google.com, jensj@google.com

Committed: https://github.com/dart-lang/kernel/commit/5a40636eef78d5ab1a87fe100ce0fd98bd7f0a22

[asgerf, 2016-10-25 14:29:09]

asgerf@google.com changed reviewers:
+ jensj@google.com, kmillikin@google.com

[ahe, 2016-10-25 14:43:34]

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

[ahe, 2016-10-25 14:43:35]

lgtm

https://codereview.chromium.org/2448873004/diff/20001/lib/ast.dart
File lib/ast.dart (right):

https://codereview.chromium.org/2448873004/diff/20001/lib/ast.dart#newcode3553
lib/ast.dart:3553: /// A tuple with file, line, and column number, for
displaying human-readable
(and Emacs-readable)

Nice touch :-)

[jensj, 2016-10-26 06:23:52]

lgtm

[asgerf, 2016-10-31 10:29:41]

Description was changed from

==========
Add convenience getter to extract the location of an AST node.

TreeNode.location is a getter for use in diagnostics and debugging.

It uses parent pointers to find the enclosing file URI and line ending
table of the node. If the node has no offset stored, it will use that
of the first enclosing parent that has an offset.

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

to

==========
Add convenience getter to extract the location of an AST node.

TreeNode.location is a getter for use in diagnostics and debugging.

It uses parent pointers to find the enclosing file URI and line ending
table of the node. If the node has no offset stored, it will use that
of the first enclosing parent that has an offset.

BUG=
R=ahe@google.com, jensj@google.com

Committed:
https://github.com/dart-lang/kernel/commit/5a40636eef78d5ab1a87fe100ce0fd98bd...
==========

[asgerf, 2016-10-31 10:29:43]

Committed patchset #2 (id:20001) manually as
5a40636eef78d5ab1a87fe100ce0fd98bd7f0a22 (presubmit successful).