Fix "if" conditions in summary Builder setters.

Fix "if" conditions in summary Builder setters.

Previously, we were generating code like:

    if (_value != null || _value == <default>) {
      <store _value in the summary>
    }

which meant that (a) default values were being unnecessarily stored in
the summaries, and (b) passing null to a summary Builder setter would
have caused a crash.

This CL modifies the code generator to output code like this:

    if (!(_value == null || _value == <default>)) {
      <store _value in the summary>
    }

which has the intended behavior of treating `null` like the default
value, and suppressing the default value from appearing in the summary.

R=brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/f1ea359020ef8b09db37d44b5a6b83d2a4317b9b

[Paul Berry, 2015-12-18 18:09:47]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Paul Berry, 2015-12-18 18:09:47]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Brian Wilkerson, 2015-12-18 18:16:02]

Description was changed from

==========
Fix "if" conditions in summary Builder setters.

Previously, we were generating code like:

    if (_value != null || _value == <default>) {
      <store _value in the summary>
    }

which meant that (a) default values were being unnecessarily stored in
the summaries, and (b) passing null to a summary Builder setter would
have caused a crash.

This CL modifies the code generator to output code like this:

    if (!(_value == null || _value == <default>)) {
      <store _value in the summary>
    }

which has the intended behavior of treating `null` like the default
value, and suppressing the default value from appearing in the summary.
==========

to

==========
Fix "if" conditions in summary Builder setters.

Previously, we were generating code like:

    if (_value != null || _value == <default>) {
      <store _value in the summary>
    }

which meant that (a) default values were being unnecessarily stored in
the summaries, and (b) passing null to a summary Builder setter would
have caused a crash.

This CL modifies the code generator to output code like this:

    if (!(_value == null || _value == <default>)) {
      <store _value in the summary>
    }

which has the intended behavior of treating `null` like the default
value, and suppressing the default value from appearing in the summary.
==========

[Brian Wilkerson, 2015-12-18 18:16:10]

LGTM

https://codereview.chromium.org/1539953002/diff/1/pkg/analyzer/tool/summary/g...
File pkg/analyzer/tool/summary/generate.dart (right):

https://codereview.chromium.org/1539953002/diff/1/pkg/analyzer/tool/summary/g...
pkg/analyzer/tool/summary/generate.dart:335: out('if (!(_value ==
null$condition)) {');
The case where there is no default value got uglier. What would you think of

if (condition.isEmpty) {
  out('if (_value != null) {');
} else {
  out('if (!(_value == null$condition)) {');
}

[Paul Berry, 2015-12-18 18:23:06]

Description was changed from

==========
Fix "if" conditions in summary Builder setters.

Previously, we were generating code like:

    if (_value != null || _value == <default>) {
      <store _value in the summary>
    }

which meant that (a) default values were being unnecessarily stored in
the summaries, and (b) passing null to a summary Builder setter would
have caused a crash.

This CL modifies the code generator to output code like this:

    if (!(_value == null || _value == <default>)) {
      <store _value in the summary>
    }

which has the intended behavior of treating `null` like the default
value, and suppressing the default value from appearing in the summary.
==========

to

==========
Fix "if" conditions in summary Builder setters.

Previously, we were generating code like:

    if (_value != null || _value == <default>) {
      <store _value in the summary>
    }

which meant that (a) default values were being unnecessarily stored in
the summaries, and (b) passing null to a summary Builder setter would
have caused a crash.

This CL modifies the code generator to output code like this:

    if (!(_value == null || _value == <default>)) {
      <store _value in the summary>
    }

which has the intended behavior of treating `null` like the default
value, and suppressing the default value from appearing in the summary.

R=brianwilkerson@google.com

Committed:
https://github.com/dart-lang/sdk/commit/f1ea359020ef8b09db37d44b5a6b83d2a4317b9b
==========

[Paul Berry, 2015-12-18 18:23:08]

Committed patchset #1 (id:1) manually as
f1ea359020ef8b09db37d44b5a6b83d2a4317b9b (presubmit successful).