Previously, TypeAliasDecl was used for typealiases, generic
parameters, and assocaited types, which is hideous and the source of
much confusion. Factor the latter two out into their own decl nodes,
with a common abstract base for "type parameters", and push these
nodes throughout the frontend.
No real functionality change, but this is a step toward uniquing
polymorphic types, among other things.
Swift SVN r7345
Add packUnionPayload and unpackUnionPayload methods to LoadableTypeInfo that pack an explosion into a union payload and unpack an explosion from a union payload.
Swift SVN r7321
Dynamic forms of these methods will ultimately move to the fully general TypeInfo class, but for now I'm focusing on getting fixed-layout unions working. Set up methods on FixedTypeInfo for getting the fixed count of extra inhabitants and the spare bit mask for a type. Have the default implementation of extra inhabitants count use the spare bits. For now, only actually set spare bits for types with IR-level single scalar non-power-of-two integer representation (e.g., i1, or i21).
Swift SVN r7289
These value witness table entries will be conditionally available for types that support specialized union representation through extra inhabitants and/or spare bits and for union value witnesses:
- storeExtraInhabitant, to store an extra inhabitant representation;
- getExtraInhabitantIndex, to recognize an extra inhabitant representation;
- getUnionTag, to get a union's discriminator; and
- inplaceProjectUnionData, to extract the value in place from a union.
This just sets up the enumerators and related IR types and mangling; nothing emits these witnesses yet.
Swift SVN r7234
the new LoadableTypeInfo refinement interface.
This protects against bugs which would introduce unbalanced
allocations of temporary memory.
Swift SVN r7227
The current implementation of dealloc_stack in IR-gen is a
no-op, but that's very much wrong for types with non-trivial
local allocation requirements, e.g. archetypes. So we need
to be able to do non-trivial code here. However, that means
modeling both the buffer pointer and the allocated address
in SIL.
To make this more type-safe, introduce a SIL-specific
'[local_storage] T' type that represents the required
allocation for locally storing a T. alloc_stack now returns
one of those in additon to a *T, and dealloc_stack expects
the former.
IR-gen still implements dealloc_stack as a no-op, but
that's now easy to fix.
Swift SVN r6937
We haven't fully updated references to union cases, and enums still are not
their own thing yet, but "oneof" is gone. Long live "union"!
Swift SVN r6783
Reserve slots in protocol witness table layout to drop in associated type metadata and witnesses. To actually populate these, we'll need to move the ABI to lazy conformance-instantiation functions.
Swift SVN r6702
Switch a few more clients from ::getInherited() to
::getProtocols(). The trajectory here is that ::getInherited() will
turn into something only populated when we've parsed the inheritance
clause, and that "the truth" will be getProtocols(). The former will
cease being serialized once this is the case.
Swift SVN r6661
The value witnesses are always available through type metadata (through an extra indirection). Saving that indirection costs 16 words (and growing!) in every witness table, and when we start instantiating conformances for generic instances, would require us to instantiate practically every generic witness table. Removing the value witnesses from the protocol witness table means we will only need to instantiate witness tables when associated types are dependent on the conforming type's type variables.
This is an ABI break, but should have no user-visible functional change.
Swift SVN r6651
"SILConstant" doesn't really describe its role in SIL anymore, which is to provide a reference to a Swift declaration in a SIL instruction, such as a method or nominal type field.
Swift SVN r6559
Have WitnessBuilder awkwardly ask SIL's TypeConverter to uncurry witness types, so that polymorphic arguments get emitted in the right order consistent with lowered SILFunctions, instead of doing the uncurrying itself directly from the Swift type. This is layer-violating as hell but gets generic witness codegen working. I have a feeling SILGen will want to take over witness thunk emission at some point.
Swift SVN r6401
If a protocol requirement is satisfied by a generic method, we'll need to save the substitutions necessary to call that method from the witness thunk. This patch adds the spot in the ProtocolConformance::Mapping to save the substitutions; for now, always leave it empty and update the code for the type change.
Swift SVN r6399
When an existential's contained type is used as a generic parameter, unwrap the existential container and save its metadata and witnesses to be used as polymorphic arguments.
Our AST representation can't quite express the distinction between a type parameter being satisfied by the existential type itself from being satisfied by the existential's contained yet. I use a goofy heuristic where I assume a protocol type bound to a type variable with no requirements is satisfied by the protocol type itself; this covers all of the existing <T> (Slice<T>, T) cases that come up in the library, while enabling the <T:Foo> (T) cases. This hopefully addresses <rdar://problem/14470097> well enough to unblock library work until we get a solid AST representation of this difference.
Swift SVN r6352
The idea for now is that this is a SIL-only type used for
representing the storage of a weak or unowned reference.
Having it be its own type is pretty vital for reasonable
behavior in SIL and IR-generation, and it's likely that
this will surface into runtime metadata as well (hence
the mangling).
I've implemented a bunch of things that technically I don't
think are necessary if this stays out of the typechecker,
but it's easier to implement half-a-dozen "recurse into
the child type" methods now that it would be to find them
all later if we change our minds.
Swift SVN r6091
Improve our representations of casts in the AST and SIL so that 'as!' and 'is' (and eventually 'as?') can share almost all of the same type-checking, SILGen, and IRGen code.
In the AST, we now represent 'as!' and 'is' as UnconditionalCheckedCastExpr and IsaExpr, respectively, with the semantic variations of cast (downcast, super-to-archetype, archetype-to-concrete, etc.) discriminated by an enum field. This keeps the user-visible syntactic and type behavior differences of the two forms cleanly separated for AST consumers.
At the SIL level, we transpose the representation so that the different cast semantics get their own instructions and the conditional/unconditional cast behavior is indicated by an enum, making it easy for IRGen to discriminate the different code paths for the different semantics. We also add an 'IsNonnull' instruction to cover the conditional-cast-result-to-boolean conversion common to all the forms of 'is'.
The upshot of all this is that 'x is T' now works for all the new archetype and existential cast forms supported by 'as!'.
Swift SVN r5737
Use the new swift_dynamicCastIndirect runtime functions to implement casts from opaque archetype and existential types to concrete types.
Swift SVN r5684
Just refer to "class archetypes" and "class protocols". Change 'isClassBounded' methods to 'requiresClass', which is a character shorter.
Swift SVN r5674
If an archetype has a superclass bound, we can assume the superclass's
retain semantics for the type. We can also use the superclass's storage pointer type to cut down on some bitcast IR noise when calling superclass methods on the archetype value.
Swift SVN r5642
Provide a lowering for the DeinitExistential instruction to deallocate the buffer in an existential container with an uninitialized value, using its deallocateBuffer witness.
Swift SVN r5623
