When applying the set of fixes introduced by a solution, don't rely on
a walk from the "root" expression of the constraint system to
attribute the fixes to expressions. Rather, collect the fixes and emit
diagnostics in source order of the expressions that pertain to.
In anticipation of eliminating this solution-application logic, centralize
to application of solutions back to the constraint system for the purpose
of applying the solution to update ASTs.
diagnosing failures in applySolutionFixes, coalesce fixes and
diagnose failures in one method on ConstraintFix.
This eliminates the need for the `DefaultGenericArgument` fix (which
was renamed from `ExplicitlySpecifyGenericArguments`) to have an
array of missing parameters, which was only used when the fixes were
coalesced. Instead, the coalesced arguments are used to create the
`MissingGenericArgumentsFailure` diagnostic directly.
It belongs on Solutionn, which should contain all of the information
needed to perform the operation. Simplify the implementation slightly
while doing this, eliminating some dead code.
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.
Using mapTypeIntoContext() is incorrect here, because we might not
be calling the default argument from the callee's context. Instead,
use the substitutions from the ConcreteDeclRef.
Fixes <rdar://problem/55739617>.
Rather than attempting to pull out a concrete decl
ref from the rewritten function expr, retrieve the
callee from the solution using a callee locator
computed before the apply is rewritten, and then
pass this callee down through `finishApply` and
`coerceCallArguments`.
Resolves SR-11648.
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.
