AnalyzeFunctions was reusing the `ReactiveScopeDependency` type since it happened to have a convenient shape, but we need to change this type to represent optionality. We now use a locally defined type instead.
ghstack-source-id: e305c6ede4
Pull Request resolved: https://github.com/facebook/react/pull/30811
Summary:
Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges.
Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends.
ghstack-source-id: e8f36ac25e
Pull Request resolved: https://github.com/facebook/react/pull/30713
This PR updates to use SSA form through the entire compilation pipeline. This means that in both HIR form and ReactiveFunction form, `Identifier` instances map 1:1 to `IdentifierId` values. If two identifiers have the same IdentifierId, they are the same instance. What this means is that all our passes can use this more precise information to determine if two particular identifiers are not just the same variable, but the same SSA "version" of that variable.
However, some parts of our analysis really care about program variables as opposed to SSA versions, and were relying on LeaveSSA to reset identifiers such that all Identifier instances for a particular program variable would have the same IdentifierId (though not necessarily the same Identifier instance). With LeaveSSA removed, those analysis passes can now use DeclarationId instead to uniquely identify a program variable.
Note that this PR surfaces some opportunties to improve edge-cases around reassigned values being declared/reassigned/depended-upon across multiple scopes. Several passes could/should use IdentifierId to more precisely identify exactly which values are accessed - for example, a scope that reassigns `x` but doesn't use `x` prior to reassignment doesn't have to take a dependency on `x`. But today we take a dependnecy.
My approach for these cases was to add a "TODO LeaveSSA" comment with notes and the name of the fixture demonstrating the difference, but to intentionally preserve the existing behavior (generally, switching to use DeclarationId when IdentifierId would have been more precise).
Beyond updating passes to use DeclarationId instead of Identifier/IdentifierId, the other change here is to extract out the remaining necessary bits of LeaveSSA into a new pass that rewrites InstructionKind (const/let/reassign/etc) based on whether a value is actually const or has reassignments and should be let.
ghstack-source-id: 69afdaee5f
Pull Request resolved: https://github.com/facebook/react/pull/30573
Updates the prettier config to format all `.ts` and `.tsx` files in the
repo using the existing defaults and removing overrides.
The first commit in this PR contains the config changes, the second is
just the result of running `yarn prettier-all`.
Joe Savona
Mike Vitousek
Jan Kassens