Pull the implicit 'Self' associated type out of the protocol and into
an implicitly-declared generic parameter list for the protocol. This
makes all of the methods of a protocol polymorphic, e.g., given
protocol P {
typealias Assoc
func getAssoc() -> Assoc
}
the type of P.getAssoc is:
<Self : P> (self : @inout P) -> () -> Self.Assoc
This directly expresses the notion that protocol methods are
polymorphic, even though 'Self' is always implicitly bound. It can be
used to simplify IRgen and some parts of the type checker, as well as
laying more of the groundwork for default definitions within
protocols as well as sundry other improvements to the generics
system.
There are a number of moving parts that needed to be updated in tandem
for this. In no particular order:
- Protocols always get an implicit generic parameter list, with a
single generic parameter 'Self' that conforms to the protocol itself.
- The 'Self' archetype type now knows which protocol it is
associated with (since we can no longer point it at the Self
associated type declaration).
- Protocol methods now get interface types (i.e., canonicalizable
dependent function types).
- The "all archetypes" list for a polymorphic function type does not
include the Self archetype nor its nested types, because they are
handled implicitly. This avoids the need to rework IRGen's handling
of archetypes for now.
- When (de-)serializing a XREF for a function type that has an
interface type, use the canonicalized interface type, which can be
meaningfully compared during deserialization (unlike the
PolymorphicFunctionType we'd otherwise be dealing with).
- Added a SIL-specific type attribute @sil_self, which extracts the
'Self' archetype of a protocol, because we can no longer refer to
the associated type "P.Self".
Swift SVN r9066
Put generic nominal type declarations through the same dependent-type
validation as generic functions, then capture their generic parameters
and requirements in their generic signature. This allows us to
re-instate the requirements in their dependent forms, before the
archetypes ruin them completely.
Swift SVN r8958
When type checking, allow the caller to customize the resolution of generic
type parameter types based on the context, for example, by choosing to
substitute in an archetype (or not) and allowing one to resolve a dependent
member reference via a specific archetype.
No actual functionality change here.
Swift SVN r8797
Instead of relying on the subpattern being a well-formed TuplePattern, let's track our own subelements so we can associate them to properties and validate them ourselves.
Swift SVN r8771
For PolymorphicFunctionType used in a SILFunction, we don't have a
corresponding Decl to share the parameter list with. In that case,
we set the owning Decl ID to 0 and add a trailing param lists.
We add a helper function to find the TypeAliasDecl for a Builtin type.
If the lookup is expensive, we can cache the lookup.
Deserializing SILBasicBlock and SILInstruction is not implemented yet.
SIL serializer and deserializer are implicitly tested when a module
contains transparant SILFunctions.
Swift SVN r8230
SerializedSILLoader to hold a list of SIL deserializers.
Also add an intial implementation of a linking pass that is run right after
SILGen to link the declaration of SILFunction to the actual definition in
the serialized module.
We add two blocks to the serialized module: a sil index block that
maps identifier to a function ID and also holds a list of function offsets,
and a sil block for the actual SILFunctions. We can probably use subblock
instead of two top-level blocks.
The serialization/de-serialization of the function hash table and the function
offsets are implemented. But we are missing handling of types (see FIXME in
the code).
ModuleFile::Serialized is made public to be used by SIL deserializer, as well
as ModuleFile::getType.
The SIL deserializer holds a pointer to the ModuleFile, it gets the sil cursor
and the sil index cursor from the ModuleFile. The other option is for SIL
deserializer to find the start of the two sil blocks within itself, thus having
less coupling with ModuleFile.
No testing case yet because we are missing handling of types.
Swift SVN r8206
We often won't need the complete substitutions, so only compute them
when needed. This also means that we don't need to serialize them into
module files.
Swift SVN r8194
few SIL instructions types.
This will be tested when we have a SIL deserializer. Testing cases covering
each implemented SIL instruction will be added.
Swift SVN r8094
As a bring-up hack, the module serializer would write a special record,
FALL_BACK_TO_TRANSLATION_UNIT, if it encountered something it didn't know
how to serialize. This then directed the deserializer to ignore the
contents of the module file and instead reload the original source file.
Now that we can serialize pretty much everything*, though, we don't need
this, and instead we'd rather know where the serialization coverage has
gaps (by asserting).
Swift SVN r7752
When performing member lookup into an existential that involves the
DynamicLookup protocol, look into all classes and protocols for that
member. References to anything found via this lookup mechanism are
returned as instances of Optional.
This introduces the basic lookup mechanics into the type
checker. There are still numerous issues to work through:
- Subscripting isn't supported yet
- There's no SILGen or IRGen support
- The ASTs probably aren't good enough for the above anyway
- References to generics will be broken
- Ambiguity resolution or non-resolution
Thanks to Jordan for the patch wiring up DynamicLookup.
Swift SVN r7689
Each nested archetype X.Y corresponds to an associated type named 'Y'
within one of the protocols to which X conforms. Record the associated
type within the archetype itself. When performing type substitutions,
use that associated type to extract the corresponding type witness
rather than looking for the type itself. This is technically more
correct (since we used the type witness for type checking), and a step
toward pulling type substitutions into the AST.
Swift SVN r7624
We previously relied on the type checker to fill in the implementation
types (swift.Slice<T> and swift.Optional<T>, respectively), which
limited our ability to perform type transformations in the AST. Now,
the AST knows how to form these implementation types on demand.
Swift SVN r7587
In Swift, a module is expected to know which libraries it needs, rather than
having this specified by an external module map. While we haven't quite
designed this yet (frameworks get this for free in Clang, for example),
we can at least provide a simple option for the common case of a module
associated with a single library.
This will probably change in the future, so I left in the more general
deserialization code I was working on before simplifying the use case.
A loaded module can in theory specify any arbitrary frameworks or libraries
as dependencies, not just a single dylib.
Swift SVN r7583
This breaks the type-canonicalization link between a generic parameter
type and the archetype to which it maps. Generic type parameter types
are now separate entities (that can eventually be canonicalized) from
archetypes (rather than just being sugar).
Most of the front end still traffics in archetypes. As a step away
from this, allow us to type-check the generic parameter list's types
prior to wiring the generic type parameter declarations to archetypes,
using the new "dependent" member type to describe assocaited
types. The archetype builder understands dependent member types and
uses them to map down to associated types when building archetypes.
Once we have assigned archetypes, we revert the dependent identifier
types within the generic parameter list to an un-type-checked state
and do the type checking again in the presence of archetypes, so that
nothing beyond the generic-parameter-list checking code has to deal
with dependent types. We'll creep support out to other dependent types
elsewhere over time.
Swift SVN r7462
Previously, we were creating the type corresponding to
class/struct/union declarations as part of creating the declaration
node, which happens at parse time. The main problem with this (at the
moment) occurs with nested nominal types, where we'd end up with the
wrong "parent" type when the type was nested inside an extension
(because the extension hadn't been resolved at the time we accessed
the parent's type). Amusingly, only code completion observed this,
because the canonical type system hid the problem. The churn in the
code-completion tests come from the fact that we now have the proper
declared type for class/struct/union declarations within extensions.
Take a step toward order-independent type checking by setting the type
of a class/struct/union declaration in type checking when we either
find the declaration (e.g., due to name lookup) or walk to the
declaration (in our walk of the whole translation unit to type-check
it), extending the existing TypeChecker::validateTypeDecl() entry
point and adding a few more callers.
The removeShadowedDecls() hack is awful; this needs to move out to the
callers, which should be abstracted better in the type checker anyway.
Incremental, non-obvious step toward fixing the representation of
polymorphic function types. This yak has a *lot* of hair.
Swift SVN r7444
Another baby step toward a proper canonical form for polymorphic
function types: generic parameters will eventually be uniquable by
their depth and index.
Swift SVN r7380
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
...by adding a new callback to ModuleLoader: loadDeclsConformingTo.
This is used only when the type checker doesn't have enough contextual
information to resolve an expression involving a literal, so it's
possible many *LiteralConvertible types will never be loaded.
Deserialization of types with conversion methods is still eager, since
there's no easy hook to tell when they're needed, but the list has been
renamed to refer to any decls that need to be eagerly deserialized, in
case we need it for other purposes in the future.
This probably won't help much in a real program, but it cuts the test
run time by about 5-10% in my build.
Swift SVN r7268
This is really two commits in one: first, change the AST and TypeChecker
to only track conformances to known protocols, and second, make sure we
can deserialize decls that conform to known protocols on demand. The
latter is necessary for the type checker to solve constraint systems that
are not fully constrained, and also requires tracking decls with conversion
methods.
Currently decls conforming to known protocols are eagerly deserialized;
that will change soon to be a new ModuleLoader callback. Decls with
conversion functions will continue to be eagerly deserialized for the near
future.
This fixes the initial regressions in making decl deserialization lazy.
Swift SVN r7264
This also makes extension-loading slightly more precise; if asked to
load extensions for some struct Foo, we will load extensions for /every/
struct Foo...but now we won't /also/ load extensions for every /class/ Foo.
Swift SVN r7260
This switches from simple lists of decls to name-based on-disk hash tables,
which allows decls to be loaded lazily when doing simple lookup (but not
code completion, at least not yet).
The on-disk hash table implementation is borrowed from Clang; eventually
it will be pushed down to LLVM's Support library. (Fortunately the
implementation is header-only.)
This breaks a few tests that rely on magic protocols like
IntegerLiteralConvertible, because the type checker won't have seen the
types that conform to those protocols yet. This will be fixed by doing
an additional "hey, modules, got any of these?" lookup.
Swift SVN r7259
- New type representation OptionalTypeRepr.
- New sugared type OptionalType.
- New base type SyntaxSugarType, parent of ArraySliceType and OptionalType.
These two are the same in a lot of ways.
- The form "T[]?" is forbidden, because it makes "Int[4][2]" oddly
different from "Int[4]?[2]". The type can be spelled "(T[])?" or
Optional<T[]>.
- Like Slice, "Optional" is just looked up in the current module. This may
or may not be the desired behavior in the long run.
<rdar://problem/14666783>
Swift SVN r7100
Previously, a module contained references to every module listed in the
ASTContext. Now, we actually only encode the imports from the TU itself,
which allows us to include access paths for scoped imports.
This is necessary to implement proper name lookup shadowing rules.
Swift SVN r7013
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
Factor the ProtocolConformance class into a small hierarchy of
protocol conformances:
- "normal" conformance, which provides a complete mapping for the
explicit conformance of a nominal type (which may be generic) to a
protocol;
- "specialized" conformance, which specializes a generic
conformance by applying a set of substitutions; and
- "inherited" conformance, which projects the conformance from a
superclass to a conformance for a subclass.
In this scheme "normal" conformances are fairly heavyweight, because
they provide a complete mapping. Normal conformances are unique,
because they're associated with explicit conformance declarations
(which cannot be repeated within a module; checking is TBD). Thus, IR
generation will eventually emit them as strong symbols.
"Specialized" and "inherited" conformances occur when we're dealing
with generic specializations or subclasses. They project most of their
members through to some underlying conformance, eventually landing at
a "normal" conformance. ASTContext is responsible for uniquing these
conformances when it sees them. The IR generation model for
specialized conformances will involve runtime specialization of the
underlying witness table; inherited conformances are probably no-ops
from the IR generation perspective.
Aside from being the right thing to do, having small, uniqued
conformances for the specialization and inheritance cases is good for
compile-time performance and memory usage. We're not really taking
advantage of this everywhere we could, yet.
This change uncovered a few existing issues (one known, one not
known), particularly because we're projecting inherited conformances
rather than building new conformances:
- <rdar://problem/14620454>: protocol witnesses to methods of
classes need to perform dynamic dispatch. See the
test/Interpreter/typeof.swift test for an example.
- <rdar://problem/14637688>: comparing NSString and String with ==
fails, because they are inter-convertible. I suspect we were missing
some protocol conformances previously, and therefore accepting this
obviously-invalid code.
Swift SVN r6865
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
This should include all of the attributes we care about for the time being.
Only the resilience attributes (not designed) and [force_inline] are left
unaccounted for.
Swift SVN r6767
This makes ProtocolConformances fully self-identifying so that a ProtocolConformance* pointer alone is enough to identify a conformance as a link entity.
We currently lose the conforming decl during deserialization because trying to deserialize a reference to an ExtensionDecl asserts out. I'll bug Jordan about that.
Swift SVN r6735
