Don't allow elements of a DartBinaryExpression to be null.

Don't allow elements of a DartBinaryExpression to be null.

Issue:
http://code.google.com/p/dart/issues/detail?id=832

Note; I'm still getting NPEs, but the corelibrary isn't being found (a
different issue between Editor/DartC usage?).

R=danrubel@google.com,mmendez@google.com

Committed: https://code.google.com/p/dart/source/detail?r=2600

[mmendez, 2011-12-19 20:01:37]

LGTM

What would a user see in the editor when this error occurs?  Will the editor log
any information about this?

http://codereview.chromium.org/8993011/diff/1/compiler/java/com/google/dart/c...
File compiler/java/com/google/dart/compiler/ast/DartBinaryExpression.java
(right):

http://codereview.chromium.org/8993011/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/ast/DartBinaryExpression.java:25:
this.arg1 = becomeParentOf(arg1 != null ? arg1 : new
DartSyntheticErrorExpression());
Nit: should you be passing the token string to the DartSyntheticErrorExpression
constructor.

[danrubel, 2011-12-19 20:58:34]

lgtm

[codefu, 2011-12-19 23:24:18]

The error has a warning in the editor about "X" is undefined, and a slew of
other errors later that wont make sense because the AST is still a bit wonky.

http://codereview.chromium.org/8993011/diff/1/compiler/java/com/google/dart/c...
File compiler/java/com/google/dart/compiler/ast/DartBinaryExpression.java
(right):

http://codereview.chromium.org/8993011/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/ast/DartBinaryExpression.java:25:
this.arg1 = becomeParentOf(arg1 != null ? arg1 : new
DartSyntheticErrorExpression());
On 2011/12/19 20:01:37, mmendez wrote:
> Nit: should you be passing the token string to the
DartSyntheticErrorExpression
> constructor.

There is no tokenString in this case as the argument is null.  Two of the other
3 pass either an empty string or a null; all three deal with string
interpolation.  I can update it to pass an empty string.