Instead of forcing the client to provide a way to de-parenthesize an
expression, the client informs flow analysis when a parenthesized
expression is encountered. This reduces the runtime overhead to zero
for non-parenthesized expressions, and it saves the front end from
having to worry about support for parenthesized expressions (since its
internal representation doesn't care about parentheses).
Change-Id: I0bb6e91c87acaa05591e1b075da18700b11e4aae
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121080
Reviewed-by: Mike Fairhurst <mfairhurst@google.com>
Rather than suppress all promotions for variables written to in
closures, we track whether a closure might exist that captures a write
to a variable, and only suppress promotions once such a closure
exists. This is consistent with what is proposed in
https://github.com/dart-lang/language/pull/473.
Contains a repro of #38791.
Change-Id: I4683581908703b510a3231b8fa8ed697121b09da
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120680
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Previously, we considered a variable to be captured by a closure if a
write to that variable occurred anywhere inside a local function. But
that was overly broad; it meant that we incorrectly classified all
written-to local variables of a local function to be captured.
This CL makes the AssignedVariables logic aware of variable
declaration sites, so that it only considers a variable to be captured
if it is written to at a lower level of local function nesting than
its declaration. As a side bonus, it means that it can now exclude
out-of-scope variables from all sets of closed-upon and written-to
variables, which should make flow analysis faster by preventing it
from spending a lot of time accounting for variables that aren't
visible.
It also adds tracking of the set of all variables written to and
captured within each top level function.
This partially reverts commit 55466fd3cc.
Change-Id: Ibcd6476445addebed13cfc5ecc470d644e519148
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120800
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
In a follow-up CL, I'm going to add logic to track the complete set of
assigned and captured variables seen so far. We will need these sets
in order to properly cancel promotions on entry to a closure or nested
function. But for performance reasons we don't want these sets to
include all variables seen in the entire file; just the local function
is sufficient.
Change-Id: I32a42075916be791f2fb7798814cec4c020e8b3b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120751
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
This makes trial_migration.dart report two new exceptions:
_EdgeBuilder&GeneralizingAstVisitor&_AssignmentChecker._checkAssignment (package:nnbd_migration/src/edge_builder.dart:2169:14) (x30)
_EdgeBuilder&GeneralizingAstVisitor&_AssignmentChecker._checkDowncast (package:nnbd_migration/src/edge_builder.dart:2351:14) (x7)
30 & 7 is not great but not terrible. These also do not break path, logging, or
charcode.
Failing tests show why we cannot correctly cover remaining cases without
a larger CL.
Change-Id: I6e510db147f60cc8ee047d45e4ce2d95d26cccc4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119533
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Mike Fairhurst <mfairhurst@google.com>
This visitor, once completed, will visit code after migration is
complete, determining the post-migration type of each expression, and
deciding where null checks are needed.
See #38472 for more information about why this is necessary.
Change-Id: I8c7dece643cf5417dbb66d5290fcdbad68d3e690
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119400
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
This interface is a callback interface that allows the client to
receive detailed information about the decisions made by the migration
tool, and the source code locations associated with those decisions.
The idea is that a client of this interface can put together a report
to the user to help them understand the behavior of the migration
tool.
The instrumentation interface mostly exposes internals of the
migration engine through some safe, non-destructive interfaces. The
interface itself is documented in the new file
pkg/nnbd_migration/lib/instrumentation.dart. For examples of what
information the client can expect to receive through the
instrumentation interface, see the new file
pkg/nnbd_migration/test/instrumentation_test.dart.
Change-Id: I079551922bff75e0e8d290819f31533c29d7b62f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117285
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
This will allow richer information to be passed back to the client
about how the nullability graph relates to the source code.
Also in this CL: eliminate the _CompoundOperatorInfo class, since
everything it tracked was already available from the
AssignmentExpression AST node.
Change-Id: I3f2a37d7cbef2c69358b5f68667f8ff8afafc517
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117283
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
This CL combines the EdgeOrigin and EdgeOriginWithLocation classes, so
that all EdgeOrigin objects are associated with source locations. And
it separates the EdgeOrigin and PotentialModification roles of the
ExpressionChecks class into two separate classes.
This will enable a follow-up CL that switches the EdgeOrigin class
over to track source locations via AST nodes rather than offsets,
which will in turn allow rich information to be delivered to the
client about how the nullability graph relates to source code.
Change-Id: I736f60f93681fbbfbd5f9ee9a5589f99f819b9aa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117282
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
This will pave the way for a follow-up CL that stores AST nodes in
EdgeOrigin objects without bloating memory usage; that in turn will
prepare for an instrumentation interface that allows the migration
client to gather useful details about how the nullability graph
relates to the source code.
Change-Id: I3689ee68de7c9969776564db4678e8c1e0344519
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117281
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
This should address ~12 exceptions whose stack trace includes the line:
_AssignmentChecker._checkAssignment_recursion (package:nnbd_migration/src/edge_builder.dart:2153:16)
Change-Id: I8375cfcc4e11b5c12c75e465d9de0af060b860dd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117160
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Mike Fairhurst <mfairhurst@google.com>
Should address ~21 exceptions whose stack trace includes the line
EdgeBuilder.visitBinaryExpression (package:nnbd_migration/src/edge_builder.dart:374:14)
Change-Id: I884ac0884e4249028219ca7ba374ec95a0849d7a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/116683
Reviewed-by: Mike Fairhurst <mfairhurst@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
This is necessary in case any parameters are found that trigger flow
analysis methods to be called.
Should address ~24 exceptions whose stack trace contains the line:
EdgeBuilder.visitBooleanLiteral (package:nnbd_migration/src/edge_builder.dart:390:19)
Change-Id: I08dc31a8acdaaf0685516aab872905f620602806
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/116488
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Paul Berry