Introduce a flag --limit-ints-to-64-bits in the VM in order to investigate the

Introduce a flag --limit-ints-to-64-bits in the VM in order to investigate the
use of Bigint (see issue #28595).
A RangeError with the message "Integer operand requires conversion to Bigint" is
thrown when a Bigint gets allocated. However, parsing a Bigint literal in Dart
source will not throw the RangeError (as long as the literal is not used).

R=asiva@google.com

Committed: https://github.com/dart-lang/sdk/commit/54c1cbd6eab80a6e3f8347b3f3e2aae40bb329c2

[regis, 2017-02-21 23:29:59]

regis@google.com changed reviewers:
+ asiva@google.com

[siva, 2017-02-22 01:48:51]

lgtm with couple of comments.

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:19170: RawBigint* Bigint::NewFromInt64(int64_t value,
Heap::Space space) {
This function seems to be used only as a convenience for converting smi and mint
values into a Hex C String, should we really throw an exception in this case? We
might end up throwing exceptions in a number of cases where only smi or mint
values are in use.

We have a bunch of unit tests which use it but other than these I don't see any
use for it.

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:19196: // be used as an operand in an operation resulting
in a Bigint.
Why do you say the value is not necessarily out of range? the caller seems to
check that the value is > Mint::kMaxValue

[regis, 2017-02-22 17:30:49]

Thanks!

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:19170: RawBigint* Bigint::NewFromInt64(int64_t value,
Heap::Space space) {
On 2017/02/22 01:48:51, siva wrote:
> This function seems to be used only as a convenience for converting smi and
mint
> values into a Hex C String, should we really throw an exception in this case?
We
> might end up throwing exceptions in a number of cases where only smi or mint
> values are in use.
> 
> We have a bunch of unit tests which use it but other than these I don't see
any
> use for it.

Done.

https://codereview.chromium.org/2708213004/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:19196: // be used as an operand in an operation resulting
in a Bigint.
On 2017/02/22 01:48:51, siva wrote:
> Why do you say the value is not necessarily out of range? the caller seems to
> check that the value is > Mint::kMaxValue

You are right. I duplicated the same comment without actually checking how this
was called. I removed this comment.

[regis, 2017-02-22 17:49:09]

Description was changed from

==========
Introduce a flag --limit-ints-to-64-bits in the VM in order to investigate the
use of Bigint (see issue #28595).
A RangeError with the message "Integer operand requires conversion to Bigint" is
thrown when a Bigint gets allocated. However, parsing a Bigint literal in Dart
source will not throw the RangeError (as long as the literal is not used).
==========

to

==========
Introduce a flag --limit-ints-to-64-bits in the VM in order to investigate the
use of Bigint (see issue #28595).
A RangeError with the message "Integer operand requires conversion to Bigint" is
thrown when a Bigint gets allocated. However, parsing a Bigint literal in Dart
source will not throw the RangeError (as long as the literal is not used).

R=asiva@google.com

Committed:
https://github.com/dart-lang/sdk/commit/54c1cbd6eab80a6e3f8347b3f3e2aae40bb329c2
==========

[regis, 2017-02-22 17:49:11]

Committed patchset #2 (id:20001) manually as
54c1cbd6eab80a6e3f8347b3f3e2aae40bb329c2 (presubmit successful).