This is dead code and can be re-added if it is needed. Right now though there
really isnt a ValueOwnershipKind that corresponds to deallocating and I do not
want to add a new ValueOwnershipKind for dead code.
Quiz: What does @_transparent on an extension actually *do*?
1) Make all members @_transparent?
2) Allow your members to be @_transparent?
3) Some other magical effect that has nothing to do with members?
The correct answer is 1), however a few places in the stdlib defined
a @_transparent extension and then proceeded to make some or all members
also @_transparent, and in a couple of places we defined a @_transparent
extension with no members at all.
To avoid cargo culting and confusion, remove the ability to make
@_transparent extensions altogether, and force usages to be explicit.
When DynamicSelfType occurs outside of a class body (for example,
inside of a SIL function), it is not enough to simply utter 'Self',
because then we lose the underlying type.
Instead, print it out as '@dynamic_self Foo', where 'Foo' is the
underlying class type or archetype, and add parser support for
the same.
Fixes <rdar://problem/27735857>.
Right now 'fileprivate' is parsed as an alias for 'private' (or
perhaps vice versa, since the semantics of 'private' haven't changed
yet). This allows us to migrate code to 'fileprivate' without waiting
for the full implementation.
not have access to their type arguments at runtime. Use this to
fix the emission of native thunks for imported ObjC-generic
initializers, since they may need to perform bridging.
For now, pseudo-genericity is all-or-nothing, but we may want to
make it apply only to certain type arguments.
Also, clean up some code that was using dead mangling nodes.
as well as on parameter decls. Also, tighten up the type checker to look at
parameter types instead of decl attributes in some cases (exposing a type
checker bug).
Still TODO:
- Reject autoclosure/noescape on non-parameter types.
- Move stdlib and other code to use noescape and autoclosure in the right
spot.
- Warn about autoclosure/noescape on parameters decls, with a fixit to move it.
- Upgrade the warning to an error.
This attribute is a stand-in for the versioning annotations
described in docs/LibraryEvolution.rst; right now it's just present
or absent, and its only effect is to make sure versioned internal
decls are treated as public at the SIL level. (This functionality
already existed for -enable-testing, so it can probably be trusted.)
Also, allow inlineable functions to reference transparent and
inline-always functions /if/ they're only called immediately (not used
as values or partial-applied), since they'll be inlined away before
emitting IR. (We should really only allow this /before/ mandatory
inlining, but we don't have a separate SIL stage for that.)
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.
in arbitrary places. This fixes a regression caught by SR-770 that
would otherwise be introduced by us removing automatic currying syntax,
it allows the use of @noescape on typealiases (resolving SR-824),
allows @noescape on nested function types (fixing rdar://19997680)
and allows @noescape to be used on local variables (fixing
rdar://19997577).
At this point, @noescape should stop being a decl attribute, but I'll bring
that up on swift-evolution.
My recent changes added "resiliently-sized" global variables, where a
global in one module is defined to be of a type from another module,
and the type's size is not known at compile time.
This patch adds the other half of the equation: when accessing a
global variable defined by another module, we want to use accessors
since we want to resiliently change global variables from stored to
computed and vice versa.
The main complication here is that the synthesized accessors are not
part of any IterableDeclContext, and require some special-casing in
SILGen and Serialization. There might be simplifications possible here.
For testing and because of how the resilience code works right now,
I added the @_fixed_layout attribute to global variables. In the
future, we probably will not give users a way to promise that a
stored global variable will always remain stored; or perhaps we will
hang this off of a different attribute, once we finalize the precise
set of attributes exposed for resilience.
There's probably some other stuff with lazy and observers I need to
think about here; leaving that for later.
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 is not wired up to SIL yet so whichever is the first value will
take precedence. We already support multiple values at the SIL level, but at the
SIL level the last value takes precedence.
Per Doug's request I added an optional transform range templated on the
attribute. This will make it easy to get all attributes from the AST of a
specific kind.
Modeling nonescaping captures as @inout parameters is wrong, because captures are allowed to share state, unlike 'inout' parameters, which are allowed to assume to some degree that there are no aliases during the parameter's scope. To model this, introduce a new @inout_aliasable parameter convention to indicate an indirect parameter that can be written to, not only by the current function, but by well-typed, well-synchronized aliasing accesses too. (This is unrelated to our discussions of adding a "type-unsafe-aliasable" annotation to pointer_to_address to allow for safe pointer punning.)
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.
A fixed layout type is one about which the compiler is allowed to
make certain assumptions across resilience domains. The assumptions
will be documented elsewhere, but for the purposes of this patch
series, they will include:
- the size of the type
- offsets of stored properties
- whether accessed properties are stored or computed
When -enable-resilience is passed to the frontend, all types become
resilient unless annotated with the @fixed_layout attribute.
So far, the @fixed_layout attribute only comes into play in SIL type
lowering of structs and enums, which now become address-only unless
they are @fixed_layout. For now, @fixed_layout is also allowed on
classes, but has no effect. In the future, support for less resilient
type lowering within a single resilience domain will be added, with
appropriate loads and stores in function prologs and epilogs.
Resilience is not enabled by default, which gives all types fixed
layout and matches the behavior of the compiler today. Since
we do not want the -enable-resilience flag to change the behavior
of existing compiled modules, only the currently-compiling module,
Sema adds the @fixed_layout flag to all declarations when the flag
is off. To reduce the size of .swiftmodule files, this could become
a flag on the module itself in the future.
The reasoning behind this is that the usual case is building
applications and private frameworks, where there is no need to make
anything resilient.
For the standard library, we can start out with resilience disabled,
while perfoming an audit adding @fixed_layout annotations in the
right places. Once the implementation is robust enough we can then
build the standard library with resilience enabled.
Revert "Fix complete_decl_attribute test for @fixed_layout"
Revert "Sema: non-@objc private stored properties do not need accessors"
Revert "Sema: Access stored properties of resilient structs through accessors"
Revert "Strawman @fixed_layout attribute and -{enable,disable}-resilience flags"
This reverts commit c91c6a789e.
This reverts commit 693d3d339f.
This reverts commit 085f88f616.
This reverts commit 5d99dc9bb8.
A fixed layout type is one about which the compiler is allowed to
make certain assumptions across resilience domains. The assumptions
will be documented elsewhere, but for the purposes of this patch
series, they will include:
- the size of the type
- offsets of stored properties
- whether accessed properties are stored or computed
When -enable-resilience is passed to the frontend, all types become
resilient unless annotated with the @fixed_layout attribute.
So far, the @fixed_layout attribute only comes into play in SIL type
lowering of structs and enums, which now become address-only unless
they are @fixed_layout. For now, @fixed_layout is also allowed on
classes, but has no effect. In the future, support for less resilient
type lowering within a single resilience domain will be added, with
appropriate loads and stores in function prologs and epilogs.
Resilience is not enabled by default, which gives all types fixed
layout and matches the behavior of the compiler today. Since
we do not want the -enable-resilience flag to change the behavior
of existing compiled modules, only the currently-compiling module,
Sema adds the @fixed_layout flag to all declarations when the flag
is off. To reduce the size of .swiftmodule files, this could become
a flag on the module itself in the future.
The reasoning behind this is that the usual case is building
applications and private frameworks, where there is no need to make
anything resilient.
For the standard library, we can start out with resilience disabled,
while perfoming an audit adding @fixed_layout annotations in the
right places. Once the implementation is robust enough we can then
build the standard library with resilience enabled.
At some point I want to propose a revised model for exports, but for now
just mark that support for '@exported' is still experimental and subject
to change. (Thanks, Max.)
