Introduce a new kind of constraint, the "value witness" constraint,
which captures a reference to a witness for a specific protocol
conformance. It otherwise acts like a more restricted form of a "value
member" constraint, where the specific member is known (as a
ValueDecl*) in advance.
The constraint is effectively dependent on the protocol
conformance itself; if that conformance fails, mark the type variables
in the resolved member type as "holes", so that the conformance
failure does not cascade.
Note that the resolved overload for this constraint always refers to
the requirement, rather than the witness, so we will end up recording
witness-method references in the AST rather than concrete references,
and leave it up to the optimizers to perform devirtualization. This is
demonstrated by the SIL changes needed in tests, and is part of the
wider resilience issue with conformances described by
rdar://problem/22708391.
Currently DeclName uses an inline representation for compound names with no argument labels. This is more compact, but it costs a spare bit that we need for other purposes. This commit switches over to representing this using a separate CompoundDeclName allocation with zero trailing argument labels instead.
Note: The change in ASTBuilder::createFunctionType is functionally minor,
but we need the FunctionType::Params computed _before_ the ExtInfo, so we
need to shuffle a bunch of code around.
The ExistentialSpecializer incorrectly assumed that an existential's conformances match an opened archetype. They don't. Opened archetypes strip inherited conformances per the ABI for generic argument passing. Existential values retain those inherited conformances (for some inexplicable reason).
- Rename ASTContext::getExistentialSignature() to
getOpenedArchetypeSiganture() because it was doing exactly the wrong
thing for existentials.
- Fix ConcreteExistentialInfo to produce the correct SubstitutionMap.
- Fix ExistentialSpecializer to generate the correct conformances for
init_existential by adding a collectExistentialConformances() helper.
Fixes <rdar://problem/57025861> "Assertion failed: (conformances.size() == numConformanceRequirements)" in ExistentialSpecializer on inlined code
This used to be a lot more relevant a long time ago when typeCheckFunctionsAndExternalDecls actually did type check external functions defined in C. Now, it serves no purpose.
The validation order change from just type checking these things eagerly doesn't seem to affect anything.
This commit moves the getNSObjectType and
getObjCSelectorType methods from TypeChecker
onto ASTContext. In addition, it moves the
FOR_KNOWN_FOUNDATION_TYPES macro into a separate
file to define each of the Obj-C type decls
we want to have access to.
The `_Differentiation` module is the experimental support library for
differentiable programming. It is built when the build-script flag
`--enable-experimental-differentiable-programming` is enabled.
The `Differentiable` protocol generalizes all types that work with
differentiation. It is a core piece of the differentiable programming
project. Other parts depending on the `Differentiable` protocol will
be upstreamed piece by piece.
The `Differentiable` protocol is compiler-known and will be used during
type-checking, SILGen, and the SIL differentiation transform.
This non-user-facing attribute is used to denote pointer parameters
which do not accept pointers produced from temporary pointer conversions
such as array-to-pointer, string-to-pointer, and in some cases
inout-to-pointer.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
