Paul Berry
f5208f5d59
`FlowModel.promotionInfo` is currently a map from integer promotion
keys to PromotionModel data structures. This is inefficient because
FlowModel is an immutable data structure, so whenever the promotion
state of a variable changes, the map must be duplicated. In a
follow-up CL I will be changing `FlowModel.promotionInfo` to a much
more efficient data structure. However, that data structure will
require some extra plumbing. For ease in code review, I'm doing the
extra plumbing first, as its own CL.
This CL makes the following changes:
- Removes unnecessary null checks from the `FlowModel.withInfo`
constructor. These null checks are no longer needed because all the
clients of flow analysis are now fully null safe. This change is not
strictly necessary; it's just a long-overdue clean-up.
- Adds a `helper` argument (of type `FlowAnalysisHelper`) to
`FlowModel.conservativeJoin`, `FlowModel.declare`, and
`FlowModel.infoFor`, `FlowModel.inheritTested`, and
`FlowModel._updatePromotionInfo`. This is needed because these
methods will need access to `FlowAnalysisHelper` in order to read
and update the new data structure.
- Removes the `typeOperations` argument of `FlowModel.inheritTested`,
since it can be easily obtained from the new `helper` argument.
- Changes `FlowModel._updatePromotionInfo` to a public method
annotated with `@visibleForTesting`. This will be needed by flow
analysis unit tests to create the new data structure.
Note that this change causes a small regression in the performance of
CFE compilation, due to the extra `helper` arguments:
instructions:u: 0.0693% +/- 0.0008% (13413234.33 +/- 155671.09)
branches:u: 0.0886% +/- 0.0012% (3502620.67 +/- 45724.97)
The follow-up CL that switches to a more efficient data structure will
result in a performance improvement roughly an order of magnitude
larger.
Change-Id: I21c13fb817f05281b558f0473119473a26ea0fb8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/326860
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
FE/analyzer shared code
This package contains logic that is shared between the front_end and analyzer packages. It is intended solely to facilitate development of the Dart SDK, and is not intended for use by end users. In particular, this package has no public API, so no guarantee is made of compatibility between one version of the package and the next.
End users should consider using the analyzer package to analyze Dart source code.