Make int and double nullable by default

Make int and double nullable by default

See patch set 1 for the initial step back and patch set 2 to try to get some of this back.

R=jmesserly@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/f51dc255ae83e23e9b705c9d044e5d64edcb8661

[vsm, 2015-03-03 18:55:16]

vsm@google.com changed reviewers:
+ jmesserly@google.com

[Jennifer Messerly, 2015-03-03 19:14:31]

"looks good" feels like the wrong comment :)

but code changes lgtm.

https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
lib/src/codegen/js_codegen.dart:1050: bool _isNonNullableExpression(Expression
expr) {
add a TODO that this will go away when we have not-nullable types in the type
system?

it's nice, but a shame we'll lose info if you assign an expr to a variable.

https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
File test/codegen/expect/BenchmarkBase.js (right):

https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
test/codegen/expect/BenchmarkBase.js:14: for (let i = 0; dart.notNull(i) <
dart.notNull(actual.length); dart.notNull(i)++) {
here's an example where the type being !null would help
(or tracking the local variable's type)

[vsm, 2015-03-03 19:29:42]

PTAL

Tighten this up a little bit by looking at JS type.

https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
lib/src/codegen/js_codegen.dart:1050: bool _isNonNullableExpression(Expression
expr) {
On 2015/03/03 19:14:30, John Messerly wrote:
> add a TODO that this will go away when we have not-nullable types in the type
> system?
> 
> it's nice, but a shame we'll lose info if you assign an expr to a variable.

Done.

https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
File test/codegen/expect/BenchmarkBase.js (right):

https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
test/codegen/expect/BenchmarkBase.js:14: for (let i = 0; dart.notNull(i) <
dart.notNull(actual.length); dart.notNull(i)++) {
On 2015/03/03 19:14:30, John Messerly wrote:
> here's an example where the type being !null would help
> (or tracking the local variable's type)

Loop vars standout - we could get most of these with local analysis - not much
different from def. assignment analysis.

[vsm, 2015-03-03 20:02:32]

On 2015/03/03 19:29:42, vsm wrote:
> PTAL
> 
> Tighten this up a little bit by looking at JS type.
> 
>
https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
> File lib/src/codegen/js_codegen.dart (right):
> 
>
https://codereview.chromium.org/977613002/diff/20001/lib/src/codegen/js_codeg...
> lib/src/codegen/js_codegen.dart:1050: bool _isNonNullableExpression(Expression
> expr) {
> On 2015/03/03 19:14:30, John Messerly wrote:
> > add a TODO that this will go away when we have not-nullable types in the
type
> > system?
> > 
> > it's nice, but a shame we'll lose info if you assign an expr to a variable.
> 
> Done.
> 
>
https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
> File test/codegen/expect/BenchmarkBase.js (right):
> 
>
https://codereview.chromium.org/977613002/diff/20001/test/codegen/expect/Benc...
> test/codegen/expect/BenchmarkBase.js:14: for (let i = 0; dart.notNull(i) <
> dart.notNull(actual.length); dart.notNull(i)++) {
> On 2015/03/03 19:14:30, John Messerly wrote:
> > here's an example where the type being !null would help
> > (or tracking the local variable's type)
> 
> Loop vars standout - we could get most of these with local analysis - not much
> different from def. assignment analysis.

Uploaded new changes - PTAL

[Jennifer Messerly, 2015-03-03 20:05:01]

Still "lgtm" ;-)

these new changes are really nice though!

https://codereview.chromium.org/977613002/diff/40001/lib/src/codegen/js_codeg...
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/977613002/diff/40001/lib/src/codegen/js_codeg...
lib/src/codegen/js_codegen.dart:1075: if (e is FunctionElement &&
at some point I wonder if we want a helper for this (my bad, using it twice in
the initial CL :) ). Anyway not a big deal though since it's not likely to
change.

[vsm, 2015-03-03 20:08:41]

Committed patchset #3 (id:40001) manually as
f51dc255ae83e23e9b705c9d044e5d64edcb8661 (presubmit successful).