of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
This speculatively re-applies 7576a91009,
i.e. reverts commit 11ab3d537f.
We have not been able to duplicate the build failure in
independent testing; it might have been spurious or unrelated.
of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
This reverts commit 6528ec2887, i.e.
it reapplies b1e3120a28, with a fix
to unbreak release builds.
This reverts commit b1e3120a28.
Reverting because this patch uses WitnessTableBuilder::PI in NDEBUG code.
That field only exists when NDEBUG is not defined, but now NextCacheIndex, a
field that exists regardless, is being updated based on information from PI.
This problem means that Release builds do not work.
of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
Fix a layout discrepancy when an associated type had @objc protocol constraints, in which case WitnessTableLayout would reserve a slot for the witness table, but WitnessTableBuilder would never emit it. Also add assertions to WitnessTableBuilder that check that the witness table we're building follows the claimed WitnessTableLayout. Fixes rdar://problem/20418117.
Swift SVN r26953
Make WitnessVisitor not freak out when it sees an init requirement, allowing 'init' requirements to be used in non-@objc protocols. Fixes <rdar://problem/13695680>.
Swift SVN r14744
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
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
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
This is kindof a pain in a few places where the type system
doesn't propagate canonicality. Also, member initializations
are always direct-initializations and so are allowed to use
explicit constructors, which is a hole in our canonicality
tracking. But overall I like the idea of always working
with canonical types.
Swift SVN r2893
