Rename 'assignment' attribute of infix operators to 'mutating'. Add
'has_assignment' attribute, which results in an implicit declaration of
the assignment version of the same operator. Parse "func =foo"
declaration and "foo.=bar" expression. Validate some basic properties of
in-place methods.
Not yet implemented: automatic generation of wrapper for =foo() if foo()
is implemented, or vice versa; likewise for operators.
Swift SVN r26508
Start allowing extensions to redeclare type parameters, which will get
different archetypes from the original nominal type. When an extension
does not redeclare type parameters, silently clone the nominal type's
generic type parameters so we still get distinct type parameters.
When deserializing an extension, wire up its generic parameter list so
we get the right archetypes for its members. This doesn't change the
module format (that happened earlier).
When determining the substitutions for an associated type that comes
from a different declaration context from the conformance that will
own the witness, be sure to map into the conformance's
DeclContext. Otherwise, we'll end up with tangled archetypes.
Fixes rdar://problem/16519588.
Swift SVN r26483
This patch also introduces some SILGen infrastructure for
dividing the function into "ordinary" and "postmatter"
sections, with error-handling-like stuff going into the
final section. Currently, this is largely undermined by
SILBuilder, but I'm going to fix that in a follow-up.
Swift SVN r26422
Change availability Fix-It notes to use a DescriptiveDeclKind so that the notes are
more precise in their description of where an availability attribute will be added.
So, for example, the note will now say "add @availability attribute to enclosing class"
instead of "add @availability attribute to enclosing type".
In these Fix-Its, I have special-cased the descriptive kind for PatternBindingDecls to
instead use the description for an associated VarDecl to avoid describing property
declarations as "pattern bindings" to the user.
Swift SVN r26420
This warning is temporarily going being a flag so that, once it is safe to place generic parameters on extensions of generic types, we can opt-in to update our code when it is convenient.
Swift SVN r26416
Minor tweaks to availability diagnostic text based on feedback from Chris, Ted, and Doug.
This changees "'foo' is only available on OS X version 10.10 or greater" to
"'foo' is only available on OS X 10.10 or newer".
This change also updates the deprecation and obsoleted diagnostics to be consistent with
the new text.
Swift SVN r26344
Instead of relying on Sema to set the existential-conforms-to-self bit, compute it lazily in the AST. This is far cleaner and more dependable than the previous solution.
Swift SVN r26225
This is still a subject of discussion on swift-dev, but it seems like clearly the right
way to go to me. If it turns out that this isn't a good direction, I'll revert this and
subsequent patches built on top of it.
Swift SVN r26168
This changes 'if let' conditions to take general refutable patterns, instead of
taking a irrefutable pattern and implicitly matching against an optional.
Where before you might have written:
if let x = foo() {
you now need to write:
if let x? = foo() {
The upshot of this is that you can write anything in an 'if let' that you can
write in a 'case let' in a switch statement, which is pretty general.
To aid with migration, this special cases certain really common patterns like
the above (and any other irrefutable cases, like "if let (a,b) = foo()", and
tells you where to insert the ?. It also special cases type annotations like
"if let x : AnyObject = " since they are no longer allowed.
For transitional purposes, I have intentionally downgraded the most common
diagnostic into a warning instead of an error. This means that you'll get:
t.swift:26:10: warning: condition requires a refutable pattern match; did you mean to match an optional?
if let a = f() {
^
?
I think this is important to stage in, because this is a pretty significant
source breaking change and not everyone internally may want to deal with it
at the same time. I filed 20166013 to remember to upgrade this to an error.
In addition to being a nice user feature, this is a nice cleanup of the guts
of the compiler, since it eliminates the "isConditional()" bit from
PatternBindingDecl, along with the special case logic in the compiler to handle
it (which variously added and removed Optional around these things).
Swift SVN r26150
We now suggest up to three Fix-Its for each reference to a potentially
unavailable symbol: one to wrap the reference in an if #os(...) { ... }
guard (if possible), one to add an @availability attribute to an enclosing
property or method (if possible), and one to add an @availability attribute
to an enclosing class/struct/extension, etc. or global function.
The goal here is not to infer the "best" Fix-It but rather to ensure
discoverability of #os() and @availability attributes. We want the user, when
faced with an availability diagnostic, to be aware of the tools in her toolbox
to deal with it.
This is still missing QoI improvements, including Fix-Its to update
existing @availability attributes and more precise wording in diagnostics
(e.g, "initializer" instead of function, "class" instead of "type"). These
improvements will come in later commits.
Swift SVN r26073
(Note that this registry isn't fully enabled yet; it's built so that
we can test it, but has not yet taken over the primary task of
managing conformances from the existing system).
The conformance registry tracks all of the protocols to which a
particular nominal type conforms, including those for which
conformance was explicitly specified, implied by other explicit
conformances, inherited from a superclass, or synthesized by the
implementation.
The conformance registry is a lazily-built data structure designed for
multi-file support (which has been a problematic area for protocol
conformances). It allows one to query for the conformances of a type
to a particular protocol, enumerate all protocols to which a type
conforms, and enumerate all of the conformances that are associated
with a particular declaration context (important to eliminate
duplicated witness tables).
The conformance registry diagnoses conflicts and ambiguities among
different conformances of the same type to the same protocol. There
are three common cases where we'll see a diagnostic:
1) Redundant explicit conformance of a type to a protocol:
protocol P { }
struct X : P { }
extension X : P { } // error: redundant explicit conformance
2) Explicit conformance to a protocol that collides with an inherited
conformance:
protocol P { }
class Super : P { }
class Sub : Super, P { } // error: redundant explicit conformance
3) Ambiguous placement of an implied conformance:
protocol P1 { }
protocol P2 : P1 { }
protocol P3 : P1 { }
struct Y { }
extension Y : P2 { }
extension Y : P3 { } // error: ambiguous implied conformance to 'P1'
This happens when two different explicit conformances (here, P2 and
P3) placed on different declarations (e.g., two extensions, or the
original definition and other extension) both imply the same
conformance (P1), and neither of the explicit conformances imply
each other. We require the user to explicitly specify the ambiguous
conformance to break the ambiguity and associate the witness table
with a specific context.
Swift SVN r26067
We parse 'try' as if it were a unary operator allowed on an
arbitrary element of an expr-sequence, but sequence-folding
constrains it to never appear on the RHS of most operators.
We do allow it on the RHS of an assignment or conditional
operator, but not if there's anything to the right which
was not parsed within the RHS.
We do this for assignments so that
var x = try whatever
and
x = try whatever
both work as you might expect.
We do this for conditionals because it feels natural to
allow 'try' in the center operand, and then disallowing it
in the right operand feels very strange.
In both case, this works largely because these operators are
assumed to be very low-precedence; there are no standard
operators which would parse outside the RHS. But if you
create one and use 'try' before it, we'll diagnose it.
Swift SVN r26052
Make this diagnostic a little nicer in other ways, too:
- Highlight the whole attribute (including the at-sign).
- Don't hardcode the string "objc".
Swift SVN r25999
In an existential context, allow 'case Enum.Case:' by implicitly introducing a cast pattern, treating it as 'case Enum.Case as Enum:'. This will be important for the error handling design, where we want ErrorType-conforming enums to be pattern-matchable out of an ErrorType existential using 'catch' patterns.
Swift SVN r25968
This reverts commit r25911. Doug points out that a known protocol is sufficient for ErrorType, and we should have a general mechanism for validating known protocols instead of burning an attribute.
Swift SVN r25935
We'll use this to recognize the ErrorType protocol and give it a special optimized representation. Since it will need to box value types in order to be pointer-sized, require that it not contain any mutating methods so that value semantics are preserved.
Swift SVN r25911
This introduces a new pattern, spelled "x?" which is sugar for
matching ".Some(x)". It also changes the parser slightly so that
_ (the discard expr) is parsed as a unary expr instead of as an
expr. This allows it to have postfix ? after it, which is important
in pattern contexts to support "case _?:".
Swift SVN r25907
Also, if warning about an accessor that comes from a stored property,
point to the property rather than the (implicit, source-location-less)
accessor decl.
Both of these changes are aimed at improving the presentation in Xcode.
rdar://problem/19927828
Swift SVN r25725
This doesn't allow 'continue' out of an if statement for the same reason we don't
allow it on switch: we'd prefer people to write loops more explicitly.
Swift SVN r25565
We didn't have a consistent way to utter attributes in diagnostics, sometimes saying the
'foo' attribute is not allowed
@foo attribute is not allowed
'foo' is not allowed
@foo is not allowed
etc. Standardize on the last one, since it is clear (with the @ sign, with no quotes, with no
'attribute' word in the diagnostic) that we're talking about an attribute. Move a bunch of
diagnostics inline with this.
Swift SVN r25524
This commit validates @availability() attribute version ranges to ensure that
a declaration is not more available than its lexically containing scope. To do so,
we find the inner-most declaration containing an @availability attribute that itself
has an @availability attribute and check that first attribute's available
version range is contained in the enclosing declaration's available range. If not,
we emit a diagnostic.
This commit removes a FIXME for checking @availability and overrides. It appears that
the FIXME is a copy/paste to/from AttributeOverrideChecker, where it still resides.
Swift SVN r25453
Always perform override checking based on the Swift type
signatures, rather than alternately relying on the Objective-C
selectors. This ensures that we get consistent override behavior for
@objc vs. non-@objc declarations throughout, and we separately make
sure that the Objective-C names line up.
This also allows us to inherit @objc'ness correctly (which didn't
quite work before), including inferring the Objective-C selector/name
(the actual subject of rdar://problem/18998564).
Fixes rdar://problem/18998564.
Swift SVN r25392
Since a function pointer doesn't carry any context, we can only form a C function pointer from a static reference to a global function or a context-free local function or closure. (Or maybe a static function applied to its metatype, but that's not handled here yet.) As a placeholder for a to-be-bikeshedded surface syntax, let the existing @cc(cdecl) attribute appear in source text when the -enable-c-function-pointers frontend flag is passed.
Swift SVN r25308
Emit a warning when the developer uses an API that has been marked deprecated with an
availability attribute. Following the Clang behavior, we will only warn if the API is
deprecated on all deployment targets. For example, if an API is deprecated as of
OS X 10.11 but the minimum deployment target is 10.10 then no warning will be emitted.
rdar://problem/17406050
Swift SVN r25288
Previously, we were using the Objective-C names to help determine
whether a declaration is an override or not. This is broken, because
we should determine overrides based on the Swift rules for
overriding, then (later) check that the Objective-C runtime will see
the same override behavior that the Swift runtime does. Address this
problem, both by taking the Objective-C selector out of the equation
when matching overrides (except for diagnostic purposes) and by
performing better validation of the Objective-C names for the
overriding vs. overridden methods/properties.
The motivating case here (from rdar://problem/18998564) is an
Objective-C initializer:
-(instancetype)initString:(NSString *)string;
When trying to override this in a Swift subclass, one naturally
writes:
override init(string: String)
which implicitly has the selector initWithString:. We ended up in an
unfortunate place where we rejected the override (because the
selectors didn't match) with a crummy diagnostic, but omitting the
"override" would result in a different conflict with the superclass.
Now, we'll treat this as an override and complain that one needs to
rename the method by adding "@objc(initString:)" (with a Fix-It, of
course). This fixes rdar://problem/18998564, but it is not ideal: the
complete solution (covered by rdar://problem/19812955) involves
reworking the dance between override and @objc so that we compute
'override' first (ignoring @objc-ness entirely), and let the
@objc'ness of the overridden declaration both imply @objc for the
overriding declaration and implicitly fix the selector. However, such
a change is too risky right now, hence the radar clone.
Swift SVN r25243
This re-applies r24987, reverted in r24990, with a fix for a spuriously-
introduced error: don't use a favored constraint in a disjunction to avoid
applying a fix. (Why not? Because favoring bubbles up, i.e. the
/disjunction/ becomes favored even if the particular branch is eventually
rejected.) This doesn't seem to affect the outcome, though: the other
branch of the disjunction doesn't seem to be tried anyway.
Finishes rdar://problem/19600325
Swift SVN r25054
And even if we don't suggest wrapping in a closure (say, because there's
already a closure involved), emit a more relevant diagnostic anyway.
(Wordsmithing welcome.)
Wrapping a function value in a closure essentially explicitly inserts a
conversion thunk that we should eventually be able to implicitly insert;
that's rdar://problem/19517003.
Part of rdar://problem/19600325
Swift SVN r24987
When comparing a requirement to a witness for @objc protocols, strip
optionality out of the types and keep track of the optionality
differences separately. When we have actually matched a witness,
diagnose any unsafe (via an error) or ill-advised (via a warning)
differences, providing Fix-Its to update the optionality.
This change addresses a usable problem introduced by the fix to
rdar://problem/18383574: witnesses for optional requirements of @objc
protocols could previously have completely wrong optionality, and we
would "allow" it by not actually matching the witness to the
requirement. Then it would happen to work at runtime because it's
@objc. Now, we match those witnesses and diagnose issues, with Fix-Its
to clean up the user's code.
Addresses rdar://problem/19656106.
Swift SVN r24939
These haven't ever been safe in Swift's development because they require
generating thunks, and we currently don't do that. However, we were letting
existential conversions slip through the cracks because we consider them
subtypes, so that /metatype/ conversions work correctly. To be concrete:
"let _: Any.Type = Int.self" is okay.
"let _: (Int) -> Void = { (_: Any) -> Void in return }" is not.
We should implement this some day; that's rdar://problem/19517003.
This produces some lousy error messages, which I intend to fix soon.
Part of rdar://problem/19600325
Swift SVN r24915
This commit adds checking for accesses of potentially unavailable getters and setters.
When walking an expression to check availability, AvailabilityWalker now keeps track of
the context for when it encounters a MemberRefExpr. This context be either
(1) the next encountered member reference could cause the member's getter to be called
(e.g., the member ref is for a read of the property); (2) the member's setter could be
called (e.g., the member ref is the left-hand-side of an assignment); or (3) the member
ref generates the lvalue for for an InOutExpr (&) -- in which case we have to assume both
the getter and the setter could be called. These diagnostics are protected by the
-enable-experimental-availability-checking flag.
This commit does not import separate getter and setter availability from Objective-C; that
is coming in a future commit.
Swift SVN r24870
Per discussion with the IB team, a class can retroactively be marked as
designable via an extension (or if not retroactively, at least from elsewhere
in the module). This matches the documentation for Objective-C.
(The attribute still has no semantics in Swift itself. The only restriction
is that it must appear on a class or an extension of a class.)
rdar://problem/19654163
Swift SVN r24837
Previously, we attempted to infer @objc-ness based on conformance, but
doing so is fraught with ordering dependencies, and just doesn't work
in the general case. Among other crimes, this allowed us to
retroactively mark a non-@objc method from an imported module as
@objc... even though nobody would ever then emit the @objc entry
points for it.
Fixes the rest of rdar://problem/18383574.
Swift SVN r24831
An optional @objc requirement within a protocol can be left
unsatisfied in a well-formed program. However, there may still be a
conflict within the Objective-C runtime if the conforming class
defines a method with the corresponding Objective-C selector(s) for
that requirement, which means that the Swift and Objective-C semantics
will differ. Diagnose such issues.
More steps along the road to fixing rdar://problem/18383574.
Diagnose conflicts between unsatisfied, optional @objc requirements and
Swift SVN r24830
