Formal access alone does not take into account @testable imports of
internal types. This prevented otherwise valid conditional conformances
of these types from compiling.
rdar://72875683
A request is intended to be a pure function of its inputs. That function could, in theory, fail. In practice, there were basically no requests taking advantage of this ability - the few that were using it to explicitly detect cycles can just return reasonable defaults instead of forwarding the error on up the stack.
This is because cycles are checked by *the Evaluator*, and are unwound by the Evaluator.
Therefore, restore the idea that the evaluate functions are themselves pure, but keep the idea that *evaluation* of those requests may fail. This model enables the best of both worlds: we not only keep the evaluator flexible enough to handle future use cases like cancellation and diagnostic invalidation, but also request-based dependencies using the values computed at the evaluation points. These aforementioned use cases would use the llvm::Expected interface and the regular evaluation-point interface respectively.
Patch up all the places that are making a syntactic judgement about the
isInvalid() bit in a ValueDecl. They may continue to use that query,
but most guard themselves on whether the interface type has been set.
Like the last commit, SourceFile is used a lot by Parse and Sema, but
less so by the ClangImporter and (de)Serialization. Split it out to
cut down on recompilation times when something changes.
This commit does /not/ split the implementation of SourceFile out of
Module.cpp, which is where most of it lives. That might also be a
reasonable change, but the reason I was reluctant to is because a
number of SourceFile members correspond to the entry points in
ModuleDecl. Someone else can pick this up later if they decide it's a
good idea.
No functionality change.
Most of AST, Parse, and Sema deal with FileUnits regularly, but SIL
and IRGen certainly don't. Split FileUnit out into its own header to
cut down on recompilation times when something changes.
No functionality change.
Since the return value of getAccessor() depends on mutable state, it
does not make sense in the request evaluator world. Let's begin by
removing some utility methods derived from getAccessor(), replacing
calls to them with calls to getAccessor().
This silences the instances of the warning from Visual Studio about not all
codepaths returning a value. This makes the output more readable and less
likely to lose useful warnings. NFC.
Our walk over the requirement interface types meant that
computing the access level of an extension member depended
on type resolution and the GSB.
Fix this by adding a new request that simply collects all
TypeDecls referenced from a TypeRepr, and compute the
extension's maximum access level using that.
If we use Structural rather than Interface type resolution when
walking the extension's requirements, we don't have to build its
generic signature first.
Most of this patch is just removing special cases for materializeForSet
or other fairly mechanical replacements. Unfortunately, the rest is
still a fairly big change, and not one that can be easily split apart
because of the quite reasonable reliance on metaprogramming throughout
the compiler. And, of course, there are a bunch of test updates that
have to be sync'ed with the actual change to code-generation.
This is SR-7134.
Rather than using RequirementRequest::visitRequirements() for its side
effects, then reading from the TypeLocs left behind, start eliminating
TypeLoc-based APIs so we pass Type and TypeRepr separately.
Add some utilities to dig into a possibly-null RequirementRepr* and dig
out the appropriate TypeReprs.
This patch removes the need for Request objects to provide a default
cycle-breaking value, instead opting to return llvm::Expected so clients
must handle a cycle failure explicitly.
Currently, all clients do the 'default' behavior, but this opens the
possibility for future requests to handle failures explicitly.
Introduce ExtensionDecl::getExtendedNominal() to provide the nominal
type declaration that the extension declaration extends. Move most
of the existing callers of the callers to getExtendedType() over to
getExtendedNominal(), because they don’t need the full type information.
ExtensionDecl::getExtendedNominal() is itself not very interesting yet,
because it depends on getExtendedType().
For now, the accessors have been underscored as `_read` and `_modify`.
I'll prepare an evolution proposal for this feature which should allow
us to remove the underscores or, y'know, rename them to `purple` and
`lettuce`.
`_read` accessors do not make any effort yet to avoid copying the
value being yielded. I'll work on it in follow-up patches.
Opaque accesses to properties and subscripts defined with `_modify`
accessors will use an inefficient `materializeForSet` pattern that
materializes the value to a temporary instead of accessing it in-place.
That will be fixed by migrating to `modify` over `materializeForSet`,
which is next up after the `read` optimizations.
SIL ownership verification doesn't pass yet for the test cases here
because of a general fault in SILGen where borrows can outlive their
borrowed value due to being cleaned up on the general cleanup stack
when the borrowed value is cleaned up on the formal-access stack.
Michael, Andy, and I discussed various ways to fix this, but it seems
clear to me that it's not in any way specific to coroutine accesses.
rdar://35399664
