When attempting to compile Swift 2 code (or any Swift code using the
Swift 2 names) in Swift 3, the compiler diagnostics are often entirely
useless because the names have changed radically enough that one
generally gets "no member named 'foo'" errors rather than a helpful
"'foo' was renamed to 'bar'" error. This makes for a very poor user
experience when (e.g.) trying to move Swift 2 code forward to Swift 3.
To improve the experience, when the Swift 2 and Swift 3 names of an
API differ, the Clang importer will produce a "stub" declaration that
matches the Swift 2 API. That stub will be marked with a synthesized
attribute
@available(unavailable, renamed: "the-swift-3-name")
that enables better diagnostics (e.g., "'foo' is unavailable: renamed
to 'bar') along with Fix-Its (courtesy of @jrose-apple's recent work)
that fix the Swift 2 code to compile in Swift 3.
This change addresses much of rdar://problem/25309323 (concerning QoI
of Swift 2 code compiled with a Swift 3 compiler), but some cleanup
remains.
This was mistakenly reverted in an attempt to fix buildbots.
Unfortunately it's now smashed into one commit.
---
Introduce @_specialize(<type list>) internal attribute.
This attribute can be attached to generic functions. The attribute's
arguments must be a list of concrete types to be substituted in the
function's generic signature. Any number of specializations may be
associated with a generic function.
This attribute provides a hint to the compiler. At -O, the compiler
will generate the specified specializations and emit calls to the
specialized code in the original generic function guarded by type
checks.
The current attribute is designed to be an internal tool for
performance experimentation. It does not affect the language or
API. This work may be extended in the future to add user-visible
attributes that do provide API guarantees and/or direct dispatch to
specialized code.
This attribute works on any generic function: a freestanding function
with generic type parameters, a nongeneric method declared in a
generic class, a generic method in a nongeneric class or a generic
method in a generic class. A function's generic signature is a
concatenation of the generic context and the function's own generic
type parameters.
e.g.
struct S<T> {
var x: T
@_specialize(Int, Float)
mutating func exchangeSecond<U>(u: U, _ t: T) -> (U, T) {
x = t
return (u, x)
}
}
// Substitutes: <T, U> with <Int, Float> producing:
// S<Int>::exchangeSecond<Float>(u: Float, t: Int) -> (Float, Int)
---
[SILOptimizer] Introduce an eager-specializer pass.
This pass finds generic functions with @_specialized attributes and
generates specialized code for the attribute's concrete types. It
inserts type checks and guarded dispatch at the beginning of the
generic function for each specialization. Since we don't currently
expose this attribute as API and don't specialize vtables and witness
tables yet, the only way to reach the specialized code is by calling
the generic function which performs the guarded dispatch.
In the future, we can build on this work in several ways:
- cross module dispatch directly to specialized code
- dynamic dispatch directly to specialized code
- automated specialization based on less specific hints
- partial specialization
- and so on...
I reorganized and refactored the optimizer's generic utilities to
support direct function specialization as opposed to apply
specialization.
Temporarily reverting @_specialize because stdlib unit tests are
failing on an internal branch during deserialization.
This reverts commit e2c43cfe14, reversing
changes made to 9078011f93.
This attribute can be attached to generic functions. The attribute's
arguments must be a list of concrete types to be substituted in the
function's generic signature. Any number of specializations may be
associated with a generic function.
This attribute provides a hint to the compiler. At -O, the compiler
will generate the specified specializations and emit calls to the
specialized code in the original generic function guarded by type
checks.
The current attribute is designed to be an internal tool for
performance experimentation. It does not affect the language or
API. This work may be extended in the future to add user-visible
attributes that do provide API guarantees and/or direct dispatch to
specialized code.
This attribute works on any generic function: a freestanding function
with generic type parameters, a nongeneric method declared in a
generic class, a generic method in a nongeneric class or a generic
method in a generic class. A function's generic signature is a
concatenation of the generic context and the function's own generic
type parameters.
e.g.
struct S<T> {
var x: T
@_specialize(Int, Float)
mutating func exchangeSecond<U>(u: U, _ t: T) -> (U, T) {
x = t
return (u, x)
}
}
// Substitutes: <T, U> with <Int, Float> producing:
// S<Int>::exchangeSecond<Float>(u: Float, t: Int) -> (Float, Int)
There's an immediate need for this in the core libs, and we have most of the necessary pieces on hand to make it easy to implement. This is an unpolished initial implementation, with the following limitations, among others:
- It doesn't support bridging error conventions,
- It relies on ObjC interop,
- It doesn't check for symbol name collisions,
- It has an underscored name with required symbol name `@cdecl("symbol_name")`, awaiting official bikeshed painting.
As a first foray into annotating attribute, add tags around attribute
names. For now, treat any decl-modifiers as keywords. We will also want
to wrap the whole attribute (including any parameters) into tags as
well, but that will require more work in the callback hanlding.
Also factor the attribute printing to handle any special cases early,
which will simplify wrapping attributes in tags, since we can then just
put the whole switch intside the pre/post callbacks.
rdar://problem/24292226
This class formalizes the common case of the "trailing allocation" idiom we use
frequently. I didn't spot any true bugs while making this change, but I did see
places where we were using the wrong pointer type or casting through void* for
no good reason. This will keep us honest.
I'll get to the other libraries soon.
Introduce a new attribute, swift3_migration, that lets us describe the
transformation required to map a Swift 2.x API into its Swift 3
equivalent. The only transformation understood now is "renamed" (to
some other declaration name), but there's a message field where we can
record information about other changes. The attribute can grow
somewhat (e.g., to represent parameter reordering) as we need it.
Right now, we do nothing but store and validate this attribute.
This reflects the fact that the attribute's only for compiler-internal use, and isn't really equivalent to C's asm attribute, since it doesn't change the calling convention to be C-compatible.
We were screwing up mutating_variant-only printing (with an extra ",
") and not properly adding the space after the attribute. Fixes
rdar://problem/21111641.
Swift SVN r29044
Reapply r28734. Argyrios updated SourceKit dependencies on swift and clang libraries in
SourceKit r28765, so this should work now.
Change the AST printer to use the new short-form @available attribute syntax for
attributes with only introduction versions. So, for example, a declaration
annotated as:
@available(iOS, introduced=8.0) @available(OSX, introduced=10.10)
func foo()
will be printed as:
@available(iOS 8.0, OSX 10.10, *) func foo()
We won't include the attribute on the short form if it has a deprecated or
obsoleted version; nor if it has a message, a rename, or marks unconditional
unavailability.
This commit has a corresponding change to the SourceKit tests.
rdar://problem/20982322
Swift SVN r28768
Change the AST printer to use the new short-form @available attribute syntax for
attributes with only introduction versions. So, for example, a declaration
annotated as:
@available(iOS, introduced=8.0)
@available(OSX, introduced=10.10)
func foo()
will be printed as:
@available(iOS 8.0, OSX 10.10, *)
func foo()
We won't include the attribute on the short form if it has a deprecated or
obsoleted version; nor if it has a message, a rename, or marks unconditional
unavailability.
There is a corresponding change to the SourceKit tests.
rdar://problem/20982322
Swift SVN r28734
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
Rather than swizzle the superclass of these bridging classes at +load time, have the compiler set their ObjC runtime base classes, using a "@_swift_native_objc_runtime_base" attribute that tells the compiler to use a different implicit base class from SwiftObject. This lets the runtime shed its last lingering +loads, and should overall be more robust, since it doesn't rely on static initialization order or deprecated ObjC runtime calls.
Swift SVN r28219
@warn_unused_result can be attached to function declarations to
produce a warning if the function is called but its result is not
used. It has two optional parameters that can be placed in
parentheses:
message="some message": a message to include with the warning.
mutable_variant="somedecl": the name of the mutable variant of the
method that should be suggested when the subject method is called on
a mutable value.
The specific use we're implementing this for now is for the mutating
and in-place operations. For example:
@warn_unused_result(mutable_variant="sortInPlace") func sort() -> [Generator.Element] { ... }
mutating func sortInPlace() { ... }
Translate Clang's __attribute__((warn_unused_result)) into
@warn_unused_result.
Implements rdar://problem/18165189.
Swift SVN r28019
Allow an unversioned 'deprecated' attribute to specify unconditional
deprecation of an API, e.g.,
@availability(*, deprecated, message="sorry")
func foo() { }
Also support platform-specific deprecation, e.g.,
@availability(iOS, deprecated, message="don't use this on iOS")
func bar() { }
Addresses rdar://problem/20562871.
Swift SVN r27355
Allow an unversioned 'deprecated' attribute to specify unconditional
deprecation of an API, e.g.,
@availability(*, deprecated, message="sorry")
func foo() { }
Also support platform-specific deprecation, e.g.,
@availability(iOS, deprecated, message="don't use this on iOS")
func bar() { }
Addresses rdar://problem/20562871.
Swift SVN r27339
This is an internal-only affordance for the numerics team to be able to work on SIMD-compatible types. For now, it can only increase alignment of fixed-layout structs and enums; dynamic layout, classes, and other obvious extensions are left to another day when we can design a proper layout control design.
Swift SVN r27323
This is the new and improved version of
__attribute__((annotate("swift1_unavailable"))), with the "improved" being
specifically that the 'availability' attribute supports a message.
This requires a corresponding Clang commit.
Swift side of rdar://problem/18768673.
Swift SVN r27053
This lets us tag imported declarations with arbitrary synthesized
protocols. Use it to handle imported raw option sets as well as the
RawRepresentable conformances of enums that come in as structs.
Swift SVN r26298
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
This has been long in coming. We always had it in IRGenOpts (in string form).
We had the version number in LangOpts for availability purposes. We had to
pass IRGenOpts to the ClangImporter to actually create the right target.
Some of our semantic checks tested the current OS by looking at the "os"
target configuration! And we're about to need to serialize the target for
debugging purposes.
Swift SVN r24468
@objc methods, initializers, deinitializers, properties, and
subscripts all produce Objective-C methods. Diagnose cases where two
such entities (which may be of different kinds) produce the same
Objective-C method in the same class.
As a special exception, one can have an Objective-C method in an
extension that conflicts with an Objective-C method in the original
class definition, so long as the original class definition is from a
different model. This reflects the reality in Objective-C that the
category definition wins over the original definition, and is used in
at least one overlay (SpriteKit).
This is the first part of rdar://problem/18391046; the second part
involves checking that overrides are sane.
Swift SVN r23147
