We used to diagnose references to unavailable declarations in
two places:
- inside Exprs, right after type checking the expression
- inside TypeReprs, from resolveType()
In broad terms, resolveType() is called with TypeReprs
stored inside both Stmts and Decls.
To handle the first case, I added a new overload of
diagAvailability() that takes a Stmt, to be called from
typeCheckStmt(). This doesn't actually walk into any Exprs
stored inside the statement; this means it only walks
Patterns and such.
For the second case, a new DeclAvailabilityChecker is
now defined in TypeCheckAccess.cpp. It's structure is
analogous to the other three walkers there:
- AccessControlChecker
- UsableFromInlineChecker
- ExportabilityChecker
The new implementation of availability checking for types
introduces a lot more code than the old online logic
it replaces. However, I hope to consolidate some of the
code duplication among the four checkers that are defined
in TypeCheckAccess.cpp, and do some other cleanups that
will make the benefit of the new approach apparent.
This change permits a subclass to redeclare an unavailable member from a superclass. For instance, suppose you write this code (or, more likely, a version where `Base` is an ObjC class):
```swift
class Base {
@available(*, unavailable) init() {}
}
class Derived: Base {
/* override */ init() {}
}
```
Previously, Swift would reject `Derived.init()` without the `override` keyword, telling you that you should add it, but it would also reject it *with* the `override` keyword, telling you that you can't override something that's unavailable. This PR makes Swift accept it without the `override` keyword; declaring it with the keyword is still forbidden.
Fixes rdar://65702529.
This makes diagnostics more verbose and accurate, because
it's possible to distinguish how many parameters there are
based on the message itself.
Also there are multiple diagnostic messages in a format of
`<descriptive-kind> <decl-name> ...` that get printed as
e.g. `subscript 'subscript'` if empty labels are omitted.
The code that diagnosed availability for types was reverse-engineering
the Type itself, rather than making use of the declaration already
stored within the TypeRepr.
More importantly, it would completely skip nested types, so it would
fail to diagnose a deprecated/unavailable “Bar” in “Foo.Bar”.
Replace the type-inspecting check with a much-simpler walk over the
components of the IdentTypeRepr that looks at the declarations stored
in the IdentTypeRepr directly. This provides proper source-location
information and handles nested types.
This is a source-breaking change for ill-formed Swift 3 code that used
nested type references to refer to something that should be unavailable.
Given that such Swift 3 code was ill-formed, and most uses of it would
crash at runtime, we likely do not need to provide specific logic to
address this in Swift 3 compatibility mode.
This time, propagate the decl marked deprecated or unavailable through
to the fix-it, so we can be sure it's a var.
https://bugs.swift.org/browse/SR-1649
This was easy with a bit of refactoring, but eventually I'd love to
converge override checking and witness checking logic a bit more.
Fixes <rdar://26183366>.
If 'x.init' appears as a member reference other than 'self.init' or 'super.init' within an initializer, treat it as a regular static member lookup for 'init' members. This allows a more explicit syntax for dynamic initializations; 'self.someMetatype()' looks too much like it's invoking a method. It also allows for partial applications of initializers using 'someMetatype.init' (though this needs some SILGen fixes, coming up next). While we're in the neighborhood, do some other correctness and QoI fixes:
- Only lookup initializers as members of metatypes, not instances, and add a fixit (instead of crashing) to insert '.dynamicType' if the initializer is found on an instance.
- Make it so that constructing a class-constrained archetype type correctly requires a 'required' or protocol initializer.
- Warn on unused initializer results. This seems to me like just the right thing to do, but is also a small guard against the fact that 'self.init' is now valid in a static method, but produces a newly-constructed value instead of delegating initialization (and evaluating to void).
Swift SVN r29344
This came out of today's language review meeting.
The intent is to match #available with the attribute
that describes availability.
This is a divergence from Objective-C.
Swift SVN r28484
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
This includes proper printing support as well as proper platform checking
when seeing if a decl is unavailable. A few other places in the code will
now use AvailabilityAttr::isUnavailable instead of just checking the
is-unavailable-always flag (and not always checking the platform).
No new tests yet because this doesn't include /parsing/ the other fields
of AvailabilityAttr. That will come next, at which point we'll test each
of the cases that has been switched over to use
AvailabilityAttr::isUnavailable.
Part of <rdar://problem/17024498>
Swift SVN r20844
There is some follow-up work remaining:
- test/stdlib/UnicodeTrie test kills the type checker without manual type annotations. <rdar://problem/17539704>
- test/Sema/availability test raises a type error on 'a: String == nil', which we want, but probably not as a side effect of string-to-pointer conversions. I'll fix this next.
Swift SVN r19477
This is all goodness, and eliminates a major source of implicit conversions.
One thing this regresses on though, is that we now reject "x == nil" where
x is an option type and the element of the optional is not Equtatable. If
this is important, there are ways to enable this, but directly testing it as
a logic value is more straight-forward.
This does not include support for pattern matching against nil, that will be
a follow on patch.
Swift SVN r18918
We weren't diagnosing initializer delegation/chaining, subscripts, or
(the one that got me concerned) members accessed through AnyObject.
Swift SVN r18271
