The refactoring that moved the substitution of the outer environment
into an opaque type archeptype into the generic environment eliminated
the need for the bound signature entirely, so remove it.
Teach `GenericEnvironment` how to lazily create opaque type archetypes,
performing the contextual substitutions as required but without
building the "bound" generic signature until required. To get here,
augment `GenericEnvironment` with knowledge of the purpose of the
environment, whether it is for normal cases (any signature), an opened
existential type, or an opaque type. For opaque types, store the
opaque type declaration and substitution map, which we also use to
uniquely find the generic environment. Among other things, this
ensures that different opaque type archetypes within the same opaque
type declaration are properly sharing a generic environment, which
wasn't happening before.
Instead of using the recursiveConcreteType and recursiveSuperclass bits in
EquivalenceClass, store an ErrorType to the cached value before we begin
archetype construction. If a recursive call attempts to get the archetype
for the same type re-entrantly, we will return an ErrorType.
Instead of using the recursiveConcreteType and recursiveSuperclass bits in
EquivalenceClass, store an ErrorType to the cached value before we begin
archetype construction. If a recursive call attempts to get the archetype
for the same type re-entrantly, we will return an ErrorType.
VS2015 had an issue with the deletion of an operator. Since VS2017 is
the minimum version that LLVM uses, we can assume that VS2017+ is in use
(_MSC_VER >= 1910). Clean up the now defunct workaround.
By convention, most structs and classes in the Swift compiler include a `dump()` method which prints debugging information. This method is meant to be called only from the debugger, but this means they’re often unused and may be eliminated from optimized binaries. On the other hand, some parts of the compiler call `dump()` methods directly despite them being intended as a pure debugging aid. clang supports attributes which can be used to avoid these problems, but they’re used very inconsistently across the compiler.
This commit adds `SWIFT_DEBUG_DUMP` and `SWIFT_DEBUG_DUMPER(<name>(<params>))` macros to declare `dump()` methods with the appropriate set of attributes and adopts this macro throughout the frontend. It does not pervasively adopt this macro in SILGen, SILOptimizer, or IRGen; these components use `dump()` methods in a different way where they’re frequently called from debugging code. Nor does it adopt it in runtime components like swiftRuntime and swiftReflection, because I’m a bit worried about size.
Despite the large number of files and lines affected, this change is NFC.
Structurally prevent a number of common anti-patterns involving generic
signatures by separating the interface into GenericSignature and the
implementation into GenericSignatureBase. In particular, this allows
the comparison operators to be deleted which forces callers to
canonicalize the signature or ask to compare pointers explicitly.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Introduced during the bring-up of the generics system in July, 2012,
Substitution (and SubstitutionList) has been completely superseded by
SubstitutionMap. R.I.P.
Replace two prominent uses of SubstitutionList, in ConcreteDeclRef and
Witness, with SubstitutionMap. Deal with the myriad places where we
now have substitution maps and need substitution lists (or vice versa)
caused by this change.
Overall, removes ~50 explicit uses of SubstitutionList (of ~400).
Replace manual substitution mapping by using the existing ProtocolConformanceRef::getAssociatedConformance helper to look up the Equatable conformance from Hashable. Replace use of manual Substitution construction with SubstitutionMaps.
The key path pattern needs to include a reference to the external descriptor, along with hooks for lowering its type arguments and indices, if any. The runtime will need to instantiate and interpolate the external component when the key path object is instantiated.
While we're here, let's also reserve some more component header bytes for future expansion, since this is an ABI we're going to be living with for a while.
Except GenericEnvironment.h, because you can't meaningfully use a
GenericEnvironment without its signature. Lots less depends on
GenericSignature.h now. NFC
SubstitutionMap::lookupConformance() would map archetypes out
of context to compute a conformance path. Do the same thing
in SubstitutionMap::lookupSubstitution().
The DenseMap of replacement types in a SubstitutionMap now
always has GenericTypeParamTypes as keys.
This simplifies some code and brings us one step closer to
a more efficient representation of SubstitutionMaps.
When looking for a conformance for an archetype, map it out of context
to compute the conformance access path, then do the actual lookups
based on mapping the starting type back into the context. Eliminate
the parent map and "walk the conformances" functionality.
This was a remnant of the old generics implementation, where
all nested types were expanded into an AllArchetypes list.
For quite some time, this method no longer returned *all*
dependent types, only those with generic requirements on
them, and all if its remaining uses were a bit convoluted.
- In the generic specialization code, we used this to mangle
substitutions for generic parameters that are not subject
to a concrete same-type constraint.
A new GenericSignature::getSubstitutableParams()
function handles this use-case instead. It is similar
to getGenericParams(), but only returns generic parameters
which require substitution.
In the future, SubstitutionLists will only store replacement
types for these generic parameters, instead of the list of
types that we used to produce from getAllDependentTypes().
- In specialization mangling and speculative devirtualization,
we relied on SubstitutionLists having the same size and
order as getAllDependentTypes(). It's better to turn the
SubstitutionList into a SubstitutionMap instead, and do lookups
into the map.
- In the SIL parser, we were making a pass over the generic
requirements before looking at getAllDependentTypes();
enumeratePairedRequirements() gives the correct information
upfront.
- In SIL box serialization, we don't serialize the size of the
substitution list, since it's available from the generic
signature. Add a GenericSignature::getSubstitutionListSize()
method, but that will go away soon once SubstitionList
serialization only serializes replacement types for generic
parameters.
- A few remaining uses now call enumeratePairedRequirements()
directly.
These are no longer necessary now that we have combineSubstitutionMaps(),
and will not make sense once we switch to a more compact representation
for SubstitutionMap.
This method maps interface types to archetypes, which in general
requires a module for performing conformance lookups, if mapping
a member type of a generic parameter which has been made concrete.
However, in practice the types we are mapping here are all canonical
with respect to the generic signature, because they came from
GenericSignature::getAllDependentTypes(), so we actually don't need
to do conformance lookups.
This allows some code to be simplified.
SubstitutionList is going to be a more compact representation of
a SubstitutionMap, suitable for inline allocation inside another
object.
For now, it's just a typedef for ArrayRef<Substitution>.
Just like the recently-added GenericSignature::getSubstitutionMap(),
this takes a type substitution function and conformance lookup
function and produces a new SubstitionMap.
Instead of creating an archetype builder with a module---which was
only used for protocol conformance lookups of concrete types
anyway---create it with a LookupConformanceFn. This is NFC for now,
but moves us closer to making archetype builders more canonicalizable
and reusable.
Teach the serialized form of ArchetypeType about its owning generic
environment, so we can wire up the generic environment of (primary)
archetypes eagerly (at the point of deserialization) rather than when
we form the generic environment. This ensures that there is no point
at which we have a (non-opened-existential) archetype without a
generic environment.
... except that the type reconstruction code creates such archetypes.
- The DeclContext versions of these methods have equivalents
on the DeclContext class; use them instead.
- The GenericEnvironment versions of these methods are now
static methods on the GenericEnvironment class. Note that
these are not made redundant by the instance methods on
GenericEnvironment, since the static methods can also be
called with a null GenericEnvironment, in which case they
just assert that the type is fully concrete.
- Remove some unnecessary #includes of ArchetypeBuilder.h
and GenericEnvironment.h. Now changes to these files
result in a lot less recompilation.
The substitution only replaces archetypes with abstract generic parameters, so no conformance lookup is necessary, and we can provide a "lookup" callback now that just vends abstract conformances.
(Ideally, we'd be able to do this for mapTypeIntoContext too, but we run into problems with generic signatures with same-type constraints on associated types with protocol requirements. Mapping `t_0_0.AssocType` into such a context will require conformance lookup for the concrete type replacement, since same-type Requirements don't preserve the conformances that satisfy the protocol requirements for the same-type relationship.)
While not strictly needed for type checking, it's extremely useful for
debugging and verification to know what context a particular generic
environment is associated with. This information was in a kludgy side
table, but it's worth a pointer in GenericEnvironment to always have
it available.
