Noticed by Slava: when the requirement is non-generic, the requirement
signature's generic signature is always going to be the same as the
conformance declaration context's generic signature, so use that immediately.
This eliminates a large number of generic signature builders created due to
requirement signatures (e.g., from 4893 -> 569 when measured against
the standard library work for SE-0157).
Short-circuit build of requirement environment.
This is all Slava and it’s magnificent.
FIXUP for “the Slava change”
In a number of cases, we would form a `GenericSignatureBuilder` as part
of computing the RequirementEnvironment, only to throw it away when we
realized we didn’t need it. Stop doing that.
Presence of some constraints (Subtype at least) requires a certain
contextual ranking of the type variables associated with them when
it comes to picking bindings, otherwise it might lead to no or
invalid solutions, because only a set of the bindings for the best
type variable is attempted.
Resolves: rdar://problem/22898292
While trying to find a fixed type for a given type variable, check if
it has representative and if it does, reflect that in the returned type.
Resolves: rdar://problem/34670592
Once we compute a generic signature from a generic signature builder,
all queries involving that generic signature will go through a separate
(canonicalized) builder, and the original builder can no longer be used.
The canonicalization process then creates a new, effectively identical
generic signature builder. How silly.
Once we’ve computed the signature of a generic signature builder, “register”
it with the ASTContext, allowing us to move the existing generic signature
builder into place as the canonical generic signature builder. The builder
requires minimal patching but is otherwise fully usable.
Thanks to Slava Pestov for the idea!
The type checker shouldn’t know about potential archetypes. Use
GenericSignatureBuilder::resolveEquivalenceClass() and perform the lookup
into that instead.
The test case change highlights an existing problem with generic signature
minimization.
Funnel all places where we create a generic signature builder to compute
the generic signature through a single entry point in the GSB
(`computeGenericSignature()`), and make `finalize` and `getGenericSignature`
private so no new uses crop up.
Tighten up the signature of `computeGenericSignature()` so it only works on
GSB rvalues, and ensure that all clients consider the GSB dead after that
point by clearing out the internal representation of the GSB.
The full state of the GSB isn’t all that useful for testing, creates a ton of noise and gets in the way of some cleanups we’d like to make in the interface.
Stop dumping it as part of `-debug-generic-signatures`.
CSDiag was misinterpreting the result of checkGenericArguments().
A result of SubstitutionFailure does not mean a diagnostic was
emitted, only a result of Failure means that. This fixes a case
where we did not emit a diagnostic, result in a crash on invalid.
The diagnostic is still poor, but that's better than crashing.
Fixes <https://bugs.swift.org/browse/SR-5932>,
<rdar://problem/34522739>.
We are currently in process of removing `InOutType`
so `VarDecl::get{Interface}Type` is going to wrap base
type into `InOutType` if its flag indicates that it's
an `inout` parameter declaration. But such type can't
be restored directly using `VarDecl::set{Interface}Type`
caller needs additional logic to extract base type.
Resolves: rdar://problem/33613329
The type checker shouldn’t know about potential archetypes. Use
GenericSignatureBuilder::resolveEquivalenceClass() and perform the lookup
into that instead.
The test case change highlights an existing problem with generic signature
minimization.
Funnel all places where we create a generic signature builder to compute
the generic signature through a single entry point in the GSB
(`computeGenericSignature()`), and make `finalize` and `getGenericSignature`
private so no new uses crop up.
Tighten up the signature of `computeGenericSignature()` so it only works on
GSB rvalues, and ensure that all clients consider the GSB dead after that
point by clearing out the internal representation of the GSB.
The full state of the GSB isn’t all that useful for testing, creates a ton of noise and gets in the way of some cleanups we’d like to make in the interface.
Stop dumping it as part of `-debug-generic-signatures`.
An unconstrained extension will always have the same generic signature as the
nominal type it extends. Rather can constructing a new generic signature
builder to tell us that, just re-use the generic signature. Improves
type-checking performance of the standard library by 15%.
When type-checking a function or subscript that itself does not have generic
parameters (but is within a generic context), we were creating a generic
signature builder which will always produce the same generic signature as
the enclosing context. Stop creating that generic signature builder.
Instead, teach the CompleteGenericTypeResolver to use the generic signature
+ the canonical generic signature builder for that signature to resolve
types, which also eliminates some extraneous re-type-checking.
Improves type-checking performance of the standard library by 36%.
This fixes a pre-existing bug where implicit DeclRefExprs involving
*any* expression of the same type within a getter were flagged with
warnings, even if they were references to something other than "self".
