This change adds UnresolvedDotExpr::createImplicit() and UnresolvedDeclRefExpr::createImplicit() helpers. These calls simplify several tedious bits of code synthesis that would otherwise become even more tedious with DeclNameRef in the picture.
Hashable doesn't quite have the know-how to reject invalid derivation contexts before hand. Give it a little help by adding a way to retrieve if a decl added to the conformance context was invalid after type checking completes. Otherwise we'll emit "Hashable is broken".
This used to be a lot more relevant a long time ago when typeCheckFunctionsAndExternalDecls actually did type check external functions defined in C. Now, it serves no purpose.
The validation order change from just type checking these things eagerly doesn't seem to affect anything.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
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.
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.
Since getSpecifier() now kicks off a request instead of always
returning what was previously set, we can't pass a ParamSpecifier
to the ParamDecl constructor anymore. Instead, callers either
call setSpecifier() if the ParamDecl is synthesized, or they
rely on the request, which can compute the specifier in three
specific cases:
- Ordinary parsed parameters get their specifier from the TypeRepr.
- The 'self' parameter's specifier is based on the self access kind.
- Accessor parameters are either the 'newValue' parameter of a
setter, or a cloned subscript parameter.
For closure parameters with inferred types, we still end up
calling setSpecifier() twice, once to set the initial defalut
value and a second time when applying the solution in the
case that we inferred an 'inout' specifier. In practice this
should not be a big problem because expression type checking
walks the AST in a pre-determined order anyway.
Implicit accessors are sometimes transparent for performance reasons.
Previously this was done in Sema by maybeMarkTransparent(), which would
add a TransparentAttr. Replace this with a request.
Accessors logically belong to their storage and can be synthesized
on the fly, so removing them from the members list eliminates one
source of mutability (but doesn't eliminate it; there are also
witnesses for derived conformances, and implicit constructors).
Since a few ASTWalker implementations break in non-trivial ways when
the traversal is changed to visit accessors as children of the storage
rather than peers, I hacked up the ASTWalker to optionally preserve
the old traversal order for now. This is ugly and needs to be cleaned up,
but I want to avoid breaking _too_ much with this commit.
We want to compute the former independently of the latter.
It's only 16 bits so storing it inside the Decl is fine;
it also allows us to eliminate the 'compact' representation
where an AbstractStorageDecl without an accessor record is
assumed to be stored.
Instead of requiring that function body synthesizers will always call
setBody(), which is annoyingly stateful, have function body synthesizers
always return the synthesized brace statement along with a bit that
indicates whether the body was already type-checked. This takes us a
step closer to centralizing the mutation of the body of a function.
Commit e0bba70 added a default implementation, however this is wrong
for non-imported types.
Instead, synthesize the body as before. Since this is one of the few
derived methods that can appear on an imported type, make sure to
build fully type-checked AST.
Fixes <rdar://problem/51322302>.
If a struct/enum cannot have Equatable/Hashable conformance automatically synthesized because a member's type is not Equatable/Hashable, add a note to the existing 'does not conform' diagnostic pointing out the type that blocked synthesis.
This is a step in the direction of fixing the fallthrough bug. Specifically, in
this commit I give case stmts a set of var decls for the bodies of the case
statement. I have not wired them up to anything except the var decl
list/typechecking.
rdar://47467128
