Introduce a new request kind to capture the computation of the set of
overridden declarations of a given declaration, eliminating the
stateful “setOverriddenDecls()” calls from the type checker.
The default move constructor and move assignment operator of AnyRequest
would leave the source object in an odd state that’s destructible but
does not maintain the invariant that all “normal” states store a real
instance. This state breaks DenseMap, which assumes that a moved-from
object is still washable.
Make the TypeChecker’s name-lookup routines static, so they don’t depend
on the TypeCheck instance… except for one pesky place where we jump back
into protocol conformance checking. This is part of teasing apart the type
checker.
From the perspective of the compiler implementation, they're elements. But users will think of these as cases—and many diagnostics already refer to these as enum cases.
Replace the last (and most obscure) use of the poor “use ‘?’ or ‘!’” diagnostic with the
new, more explanatory version that provides separate notes with Fix-Its for coalescing or
force-unwrapping the value.
Finishes rdar://problem/42081852.
Improve diagnostics when referencing a member of an optional base, where the
Optional type does not have the member but the wrapped type does. Specifically,
suggest both the chaining ‘?’ and the force-unwrapping ‘!’ Fix-Its via explanatory
notes, e.g.:
error: value of optional type '[Int]?' must be unwrapped to refer to member 'subscript' of wrapped base type '[Int]'
return foo.array[0]
^
note: chain the optional using '?' to access member 'subscript' only for non-'nil' base values
return foo.array[0]
^
?
note: force-unwrap using '!' to abort execution if the optional value contains 'nil'
return foo.array[0]
^
!
More of rdar://problem/42081852.
When we determine that an optional value needs to be unwrapped to make
an expression type check, use notes to provide several different
Fix-It options (with descriptions) rather than always pushing users
toward '!'. Specifically, the errors + Fix-Its now looks like this:
error: value of optional type 'X?' must be unwrapped to a value of
type 'X'
f(x)
^
note: coalesce using '??' to provide a default when the optional
value contains 'nil'
f(x)
^
?? <#default value#>
note: force-unwrap using '!' to abort execution if the optional
value contains 'nil'
f(x)
^
!
Fixes rdar://problem/42081852.
Parse-only invocations do not support the proper creation of dependency files or reference dependency files because they have not yet run name binding. Ban these invocations by diagnostic and add a new diagnostic specifically for reference dependencies.
I picked accessors that not only return the same result every time,
but also do no interesting validation work with possible side effects.
We have a lot more accessors that return the same result but also
force a bunch of things to be loaded or diagnostics to be emitted, and
I didn't want to change the behavior of any of those.
No intended functionality change; this is just supposed to be a small
optimization hint.
When users override a SDK function whose parameter types have been changed,
we should introduce a local variable in the body of the function definition
to shadow the changed parameter. Also, a proper conversion function should
be applied to bridge the parameter to the local variable.
rdar://41828411
The diagnostic when a user attempts to pass an argument requiring an implicit conversion (e.g. declared as a subclass, type conforming to protocol, etc.) to an inout parameter seems to be confusing for users—see e.g. SR-8155, SR-8148. This change replaces it with a more specific diagnostic which clearly suggests a solution. It also includes a fix-it suggesting the user change the type of the original variable if it’s a local with a simple type signature.
