Codable's deep magic currently forces conformance checks in the middle
of name lookup in order to inject CodingKeys into lookup results. This
is compounded by the fact that this lookup fixup is occuring
incrementally, meaning depending on order of requirements being looked
up, Decl::getMembers() will give you a different answer.
Compounding this, NameLookup relied on the LazyResolver to formalize
this layering violation, and relied on implicit laziness to guard
against re-entrancy.
The approach is multi-pronged:
1) Shift the layering violation into the request evaluator
2) Spell out the kinds of resolution we support explicitly (make them
easier to find and kill)
3) Remove the LazyResolver entrypoint this was relying on
4) Split off the property wrappers part into its own utility
Now that isInvalid() is a semantic property, drop the assertion for this
invariant in the ASTVerifier. This should also remove the last client
that wasn't registering the lazy resolver and expecting to pull any old
interface type out, so change a hack to an assertion to hopefully catch
future callers before we remove the LazyResolver entirely.
This non-user-facing attribute is used to denote pointer parameters
which do not accept pointers produced from temporary pointer conversions
such as array-to-pointer, string-to-pointer, and in some cases
inout-to-pointer.
It's nice to be able to set a breakpoint on this method when
debugging the type checker, but recently we started unconditionally
calling it to get the circularity sentinel before kicking off a
request.
Instead, let's only call it when we're in the failure path.
* [Sema] Factor out shouldAttemptInitializerSynthesis
This makes sure we don't attempt to synthesize
a memberwise or default initializer for an invalid
decl, or one in a module interface.
* [Sema] Requesify inheritsSuperclassInitializers
This commit introduces a request for computing
whether a class inherits both designated and
convenience initializers from its superclass.
The shared logic of finding initializers which the
subclass hasn't overriden has been factored out
into `collectNonOveriddenSuperclassInits`.
* Cleanup addImplicitInheritedConstructorsToClass
This commit removes some code that's no longer
needed. In addition, now that we've requestified
`inheritsSuperclassInitializers`, we can directly
diagnose on non-inherited required convenience
inits within the loop.
* Inherited init synthesis no longer deals with clang decls
Now that the computation of
`inheritsSuperclassInitializers` has been split off
into a request, we can avoid calling
`addImplicitInheritedConstructorsToClass` for clang
decls.
* Address review feedback
Continue to cache the InheritsSuperclassInits bit
on the AST.
This commit adds two requests, one to compute
whether or not a decl should have a default
initializer, and another to synthesize it.
This then allows us to remove the default constructor
synthesis from addImplicitConstructorsToClass as
well as completely eliminate addImplicitConstructorsToStruct.
For now, we can just force the requests in
addImplicitConstructors.
Use the request evaluator to get the easier in-module precedence group cycles. Unfortunately, cross-module precedence group cycles are still a possibility, and do not actually cause cyclic request evaluation, so we cannot completely erase the old diagnostics machinery.
Move the machinery itself into the type checker and shift the request into that zone as well to appease the linker.
The moment you've all been waiting for...
Define InterfaceTypeRequest and use it to, well, compute the interface
type. This naturally widens the few cycles that we pick up with the
request evaluator.
There is still a lot of work to get done here, mostly around scaling
back all of the ad-hoc circularity checks around the interface type
computation. It would also be great to improve the circularity
diagnostics.
Switch most callers to explicit indices. The exceptions lie in things that needs to manipulate the parsed output directly including the Parser and components of the ASTScope. These are included as friend class exceptions.
Use it to provide an idealized API for the VarDecl case in validateDecl.
In reality, a lot of work is needed to rationalize the dependency
structure of this request. To start, the callers of
typeCheckPatternBinding must be eliminated piecemeal. Once that is
done, the AST should introduce pattern binding decls along all the
places where getParentStmt() used to apply.
When Decl::getLoc() is called upon a serialized AST and the
serialized source location is available, we lazily open the
external buffer and return a valid SourceLoc instance pointing
into the buffer.
Inline the interface type reset into its callers and make sure they're
also setting the invalid bit - which this was not doing before.
Unfortunately, this is not enough to be able to simplify any part of var
decl validation.
This is an amalgam of simplifications to the way VarDecls are checked
and assigned interface types.
First, remove TypeCheckPattern's ability to assign the interface and
contextual types for a given var decl. Instead, replace it with the
notion of a "naming pattern". This is the pattern that semantically
binds a given VarDecl into scope, and whose type will be used to compute
the interface type. Note that not all VarDecls have a naming pattern
because they may not be canonical.
Second, remove VarDecl's separate contextual type member, and force the
contextual type to be computed the way it always was: by mapping the
interface type into the parent decl context.
Third, introduce a catch-all diagnostic to properly handle the change in
the way that circularity checking occurs. This is also motivated by
TypeCheckPattern not being principled about which parts of the AST it
chooses to invalidate, especially the parent pattern and naming patterns
for a given VarDecl. Once VarDecls are invalidated along with their
parent patterns, a large amount of this diagnostic churn can disappear.
Unfortunately, if this isn't here, we will fail to catch a number of
obviously circular cases and fail to emit a diagnostic.
VarDecls inherit their TypeRepr from their enclosing pattern, if any.
To retrieve the TypeRepr attached to a VarDecl or a ParamDecl in
a uniform way, the getTypeReprOrParentPatternTypeRepr API has been
provided.
TypeCheckPattern used to splat the interface type into this, and
different parts of the compiler would check one or the other. There is
now one source of truth: The interface type. The type repr is now just
a signal that the user has written an explicit type annotation on
a parameter. For variables, we will eventually be able to just grab
this information from the parent pattern.
