Fix capturing variables in optimized compilations

Fix capturing variables in optimized compilations

When a local function gets compiled the second time, constant
expressions may not be parsed again, since the constant value
is found in the cache. If the expression refers to an outer
variable, it does not get captured correctly.

Fix: instead of parsing a local function repeatedly to capture
outer variables, use the local function’s context scope to mark
outer variables as captured. This fixes the bug, and makes the
compiler more efficient as well.

No wall-time improvement found when running dart2js, though.

BUG=26453
R=regis@google.com

Committed: https://github.com/dart-lang/sdk/commit/3968005cc8cc2509ac8e47fe2e5aa989569e43df

[hausner, 2016-05-16 22:19:51]

Description was changed from

==========
Fix capturing variables in optimized compilations

When a local function gets compiled the second time, constant
expressions may not be parsed again, since the constant value
is found in the cache. If the expression refers to an outer
variable, it does not get captured correctly.

Fix: instead of parsing a local function repeatedly to capture
outer variables, use the local function’s context scope to mark
outer variables as captured. This fixes the bug, and makes the
compiler more efficient as well.

No wall-time improvement found when running dart2js, though.

BUG=26453
==========

to

==========
Fix capturing variables in optimized compilations

When a local function gets compiled the second time, constant
expressions may not be parsed again, since the constant value
is found in the cache. If the expression refers to an outer
variable, it does not get captured correctly.

Fix: instead of parsing a local function repeatedly to capture
outer variables, use the local function’s context scope to mark
outer variables as captured. This fixes the bug, and makes the
compiler more efficient as well.

No wall-time improvement found when running dart2js, though.

BUG=26453
==========

[hausner, 2016-05-16 22:19:51]

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

[regis, 2016-05-16 22:42:15]

LGTM

https://codereview.chromium.org/1980193002/diff/1/runtime/vm/ast.h
File runtime/vm/ast.h (right):

https://codereview.chromium.org/1980193002/diff/1/runtime/vm/ast.h#newcode543
runtime/vm/ast.h:543: LocalScope* scope)  // Null for implicit closures.
... or for closures that have already been compiled.

https://codereview.chromium.org/1980193002/diff/1/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/1980193002/diff/1/runtime/vm/parser.cc#newcod...
runtime/vm/parser.cc:7690: // The local function was parsed before. The captrued
variables are
captured

[hausner, 2016-05-16 22:53:05]

Description was changed from

==========
Fix capturing variables in optimized compilations

When a local function gets compiled the second time, constant
expressions may not be parsed again, since the constant value
is found in the cache. If the expression refers to an outer
variable, it does not get captured correctly.

Fix: instead of parsing a local function repeatedly to capture
outer variables, use the local function’s context scope to mark
outer variables as captured. This fixes the bug, and makes the
compiler more efficient as well.

No wall-time improvement found when running dart2js, though.

BUG=26453
==========

to

==========
Fix capturing variables in optimized compilations

When a local function gets compiled the second time, constant
expressions may not be parsed again, since the constant value
is found in the cache. If the expression refers to an outer
variable, it does not get captured correctly.

Fix: instead of parsing a local function repeatedly to capture
outer variables, use the local function’s context scope to mark
outer variables as captured. This fixes the bug, and makes the
compiler more efficient as well.

No wall-time improvement found when running dart2js, though.

BUG=26453
R=regis@google.com

Committed:
https://github.com/dart-lang/sdk/commit/3968005cc8cc2509ac8e47fe2e5aa989569e43df
==========

[hausner, 2016-05-16 22:53:06]

Committed patchset #2 (id:20001) manually as
3968005cc8cc2509ac8e47fe2e5aa989569e43df (presubmit successful).