Previously some decls (TypeAliasDecl and ExtensionDecl) had bits
explicitly marking whether they've been validated, while other decls
just deduced this from hasInterfaceType. The doing the latter doesn't
work when the interface type can be computed before doing full
validation (such as protocols and associatedtypes, which have trivial
interface types), and so an explicit bit is adopted for all decls.
The list of directly inherited protocols of a ProtocolDecl is already
encoded in the requirement signature, as conformance constraints where
the subject is Self. Gather the list from there rather than separately
computing/storing the list of "inherited protocols".
When we deserialize a protocol declaration, we had a bunch of
intervening code before it would deserialize and wire up its generic
parameter (Self), including configuring the generic environment. If
any of that code referenced an AssociatedTypeDecl of that protocol,
the deserialization of the AssociatedTypeDecl could end up computing
an erroneous type.
This might be the source of the nondeterministic deserialization
failure that seems to afflict AssociatedTypeDecls in
rdar://problem/30382791.
Previously looking up an extension would result in all extensions for
types with the same name (nested or not) being deserialized; this
could even bring in base types that had not been deserialized yet. Add
in a string to distinguish an extension's base type; in the top-level
case this is just a module name, but for nested types it's a full
mangled name.
This is a little heavier than I'd like it to be, since it means we
mangle names and then throw them away, and since it means there's a
whole bunch of extra string data in the module just for uniquely
identifying a declaration. But it's correct, and does less work than
before, and fixes a circularity issue with a nested type A.B.A that
apparently used to work.
https://bugs.swift.org/browse/SR-3915
Rather than serializing the complete structure of all archetypes
(which is completely redundant), serialize a reference to their owning
generic environment as well as their interface type. The archetype
itself will be reconsituted by mapping the interface type into that
generic environment.
Another spurious failure we're seeing occasionally in CI: a
deserialization issue involving the interface types of parameter
declarations. If this happens---either when serializing or
deserializing---dump some more debugging information.
This biggest change is:
- LayoutConstraintInfo is now a FoldingSetNode, which allows for proper canonicalization of LayoutConstraints. This is important for the correctness of type comparisons if types contain layout constraints.
No functionality changes from the client's point of view.
There's a speculative path note warning people about accidentally
using swiftmodules whose dependencies might have changed, but this
doesn't make sense when the module with the problem is also the
module being built (which happens during the module-merging phase
of multi-file compilation). In that case, pay an extra branch to
avoid showing the note.
No intended functionality change.
Introduce an algorithm to canonicalize and minimize same-type
constraints. The algorithm itself computes the equivalence classes
that would exist if all explicitly-provided same-type constraints are
ignored, and then forms a minimal, canonical set of explicit same-type
constraints to reform the actual equivalence class known to the type
checker. This should eliminate a number of problems we've seen with
inconsistently-chosen same-type constraints affecting
canonicalization.
Every other declaration kind gets this for free in its interface type,
but properties don't. Just add a bit, it's simple enough.
rdar://problem/30289803
Storing this separately is unnecessary since we already
serialize the enum element's interface type. Also, this
eliminates one of the few remaining cases where we serialize
archetypes during AST serialization.
There's a class of errors in Serialization called "circularity
issues", where declaration A in file A.swift depends on declaration B
in file B.swift, and B also depends on A. In some cases we can manage
to type-check each of these files individually due to the laziness of
'validateDecl', but then fail to merge the "partial modules" generated
from A.swift and B.swift to form a single swiftmodule for the library
(because deserialization is a little less lazy for some things). A
common case of this is when at least one of the declarations is
nested, in which case a lookup to find that declaration needs to load
all the members of the parent type. This gets even worse when the
nested type is defined in an extension.
This commit sidesteps that issue specifically for nested types by
creating a top-level, per-file table of nested types in the "partial
modules". When a type is in the same module, we can then look it up
/without/ importing all other members of the parent type.
The long-term solution is to allow accessing any members of a type
without having to load them all, something we should support not just
for module-merging while building a single target but when reading
from imported modules as well. This should improve both compile time
and memory usage, though I'm not sure to what extent. (Unfortunately,
too many things still depend on the whole members list being loaded.)
Because this is a new code path, I put in a switch to turn it off:
frontend flag -disable-serialization-nested-type-lookup-table
https://bugs.swift.org/browse/SR-3707 (and possibly others)
This is dead code and can be re-added if it is needed. Right now though there
really isnt a ValueOwnershipKind that corresponds to deallocating and I do not
want to add a new ValueOwnershipKind for dead code.
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.
The typedef `swift::Module` was a temporary solution that allowed
`swift::Module` to be renamed to `swift::ModuleDecl` without requiring
every single callsite to be modified.
Modify all the callsites, and get rid of the typedef.
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.
Teach the serialization of SIL generic environments, which used to be
a trailing record following the SIL function definition, to use the
same uniqued "generic environment IDs" that are used for the AST
generic environments. Many of them overlap anyway, and SIL functions
tend to have AST generic environments anyway.
This approach guarantees that the AST + SIL deserialization provide
the same uniqueness of generic environments present prior to
serialization.
Like c70a5a5d67, but for deserialization. This was causing assertion
failures during the merge-module step of building a module that had a
private/fileprivate protocol with an associated type because the
associated type wouldn't have a valid private discriminator (because
the original source file didn't consider it to be private).
https://bugs.swift.org/browse/SR-2576
