Compile tearoffs of static functions as constants.

Compile tearoffs of static functions as constants.

BUG=
R=zerny@google.com

Committed: https://github.com/dart-lang/fletch/commit/efdb86b437643ce6b2bbf06878cfc6528d1dd352

[Anders Johnsen, 2015-04-06 12:57:46]

ajohnsen@google.com changed reviewers:
+ zerny@google.com

[zerny-google, 2015-04-07 08:05:05]

lgtm

[Anders Johnsen, 2015-04-07 08:18:53]

Committed patchset #1 (id:1) manually as
efdb86b437643ce6b2bbf06878cfc6528d1dd352 (presubmit successful).

[ahe, 2015-04-07 15:00:10]

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

[ahe, 2015-04-07 15:00:11]

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
File pkg/fletchc/lib/src/codegen_visitor.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:195:
context.markConstantUsed(constant);
Why isn't this called for other constants?

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/fletch_...
File pkg/fletchc/lib/src/fletch_constants.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/fletch_...
pkg/fletchc/lib/src/fletch_constants.dart:64: class FletchClassInstanceConstant
extends ConstantValue {
Why is this needed?

[ahe, 2015-04-07 15:03:30]

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
File pkg/fletchc/lib/src/codegen_visitor.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:1106: if (value >= 0x3FFFFFFF) {
0x3FFFFFFF should probably be a named constant with some documentation.

Also, what happens if value is a negative value of high magnitude?

[Anders Johnsen, 2015-04-08 06:32:14]

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
File pkg/fletchc/lib/src/codegen_visitor.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:195:
context.markConstantUsed(constant);
On 2015/04/07 15:00:11, ahe wrote:
> Why isn't this called for other constants?

It is, through "compileConstant".

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:1106: if (value >= 0x3FFFFFFF) {
On 2015/04/07 15:03:30, ahe wrote:
> 0x3FFFFFFF should probably be a named constant with some documentation.
> 
> Also, what happens if value is a negative value of high magnitude?

literal ints are never negative.

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/fletch_...
File pkg/fletchc/lib/src/fletch_constants.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/fletch_...
pkg/fletchc/lib/src/fletch_constants.dart:64: class FletchClassInstanceConstant
extends ConstantValue {
On 2015/04/07 15:00:11, ahe wrote:
> Why is this needed?

Because we create artificial constants, not present in the Dart system: a const
instance of a generated tearoff class.

[ahe, 2015-04-08 08:04:18]

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
File pkg/fletchc/lib/src/codegen_visitor.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:725: if (compiledClass.fields == 0) {
Why is it the number of fields that determine if you use
allocateConstantClassInstance?

You stated that the reason for using FletchClassInstanceConstant is that
compiledClass isn't a real class. Why is that the same as having no fields?

Also, when would the tearoff class have fields?

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:1106: if (value >= 0x3FFFFFFF) {
On 2015/04/08 06:32:13, Anders Johnsen wrote:
> On 2015/04/07 15:03:30, ahe wrote:
> > 0x3FFFFFFF should probably be a named constant with some documentation.
> > 
> > Also, what happens if value is a negative value of high magnitude?
> 
> literal ints are never negative.

Assert that?

[Anders Johnsen, 2015-04-08 08:37:58]

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
File pkg/fletchc/lib/src/codegen_visitor.dart (right):

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:725: if (compiledClass.fields == 0) {
On 2015/04/08 08:04:18, ahe wrote:
> Why is it the number of fields that determine if you use
> allocateConstantClassInstance?
> 
> You stated that the reason for using FletchClassInstanceConstant is that
> compiledClass isn't a real class. Why is that the same as having no fields?
> 
> Also, when would the tearoff class have fields?

Because the field is not a constant - it can only be a constant if it doesn't
have any fields. But in this case, we can assert it.

https://codereview.chromium.org/1059573004/diff/1/pkg/fletchc/lib/src/codegen...
pkg/fletchc/lib/src/codegen_visitor.dart:1106: if (value >= 0x3FFFFFFF) {
On 2015/04/08 08:04:18, ahe wrote:
> On 2015/04/08 06:32:13, Anders Johnsen wrote:
> > On 2015/04/07 15:03:30, ahe wrote:
> > > 0x3FFFFFFF should probably be a named constant with some documentation.
> > > 
> > > Also, what happens if value is a negative value of high magnitude?
> > 
> > literal ints are never negative.
> 
> Assert that?

Done.