This abbreviation for "if and only if" is confusing to those not coming
from a background in formal mathematics, and is frequently reported as a
type by developers reading the documentation.
This commit also changes doc comments in internal and private members,
which don't become part of the public documentation, because omitting
"iff" everywhere makes it much easier to check for any later changes
that reintroduce it.
And set this option in various presets for buildbots.
Don't enable the checks by default because when linking against the OS library (which does not support COW checking) it will result in unresolved symbol errors.
So far it was handled by an availability checks against 9999 (which was a hack), but this does not work anymore.
Note, all this is only relevant for assert builds of the stdlib.
rdar://83673798
`_copyContents(initializing:)` is a core method of Sequence, and it is used surprisingly often to copy stuff out of sequences. Array’s internal types currently have explicit implementations of it that trap (to prevent a performance bug due to the default iterator-based implementation. This has proved a bad idea, as not all code paths that end up calling `_copyContents` have actually been expunged — so we replaced a performance bug with a catastrophic correctness bug. 😥
Rather than trying to play whack-a-mole with code paths that end up in `_copyContents`, replace the traps with (relatively) efficient implementations, based on the ancient `_copyContents(subRange:initializing)` methods that have already been there all this time.
This resolves https://bugs.swift.org/browse/SR-14663.
I expect specialization will make this fix deploy back to earlier OSes in most (but unfortunately not all) cases.
Use the new builtins for COW representation in Array, ContiguousArray and ArraySlice.
The basic idea is to strictly separate code which mutates an array buffer from code which reads from an array.
The concept is explained in more detail in docs/SIL.rst, section "Copy-on-Write Representation".
The main change is to use beginCOWMutation() instead of isUniquelyReferenced() and insert endCOWMutation() at the end of all mutating functions. Also, reading from the array buffer must be done differently, depending on if the buffer is in a mutable or immutable state.
All the required invariants are enforced by runtime checks - but only in an assert-build of the library: a bit in the buffer object side-table indicates if the buffer is mutable or not.
Along with the library changes, also two optimizations needed to be updated: COWArrayOpt and ObjectOutliner.
This fixes a major perform bug involving array initialization from any
contiguously stored collection. This is not a recent regression. This fix
results in a 10,000X speedup (that's 4 zeros) for this code path:
func initializeFromSlice(_ a: [Int]) -> [Int] {
return Array<Int>(a[...])
}
A benchmark is included.
Inlinable code is permitted to rely on these associated types, so we
need to make sure their declarations are printed in the parseable
interface.
Part of rdar://problem/43824052
* Make Range conditionally a Collection
* Convert ClosedRange to conditionally a collection
* De-gyb Range/ClosedRange, refactoring some methods.
* Remove use of Countable{Closed}Range from stdlib
* Remove Countable use from Foundation
* Fix test errors and warnings resulting from Range/CountableRange collapse
* fix prespecialize test for new mangling
* Update CoreAudio use of CountableRange
* Update SwiftSyntax use of CountableRange
* Restore ClosedRange.Index: Hashable conformance
* Move fixed typechecker slowness test for array-of-ranges from slow to fast, yay
* Apply Doug's patch to loosen test to just check for error
Using && here causes us to go down a SILGen path that guarantees that self will
be evaluated over the entire && expression instead of just the LHS. This cause
the uniqueness check to always return false at -Onone. At -O, the optimizer is
smart enough to remove this issue.
rdar://33358110
* Give Sequence a top-level Element, constrain Iterator to match
* Remove many instances of Iterator.
* Fixed various hard-coded tests
* XFAIL a few tests that need further investigation
* Change assoc type for arrayLiteralConvertible
* Mop up remaining "better expressed as a where clause" warnings
* Fix UnicodeDecoders prototype test
* Fix UIntBuffer
* Fix hard-coded Element identifier in CSDiag
* Fix up more tests
* Account for flatMap changes
A recent change made accessibility checking stricter. This had some
fallout on the half-baked @_versioned attribute, where we could no
longer define @_versioned members on a non-@_versioned type.
This was wrong anyway (and will be diagnosed when we add proper
diagnostics for @_versioned), because type metadata for the
internal type did not get the right linkage, but it used to work
as long as you didn't try to get the type metadata at runtime.
This patch adds @_versioned attributes to the right types now that
this broken behavior is gone.
As a result, _Variant{Set,Dictionary}Storage became resilient
(non-@_versioned internal types are not resilient), which broke
too many tests that assumed you can exhaustively switch over all
the cases. Since eager-bridging is going to eliminate this enum
anyway (or so I've heard), make it @_fixed_layout for now.
* Migrate from `UnsafePointer<Void>` to `UnsafeRawPointer`.
As proposed in SE-0107: UnsafeRawPointer.
`void*` imports as `UnsafeMutableRawPointer`.
`const void*` imports as `UnsafeRawPointer`.
Occurrences of `UnsafePointer<Void>` are replaced with UnsafeRawPointer.
* Migrate overlays from UnsafePointer<Void> to UnsafeRawPointer.
This requires explicit memory binding in several places,
particularly in NSData and CoreAudio.
* Fix a bunch of test cases for Void->Raw migration.
* qsort takes IUO values
* Bridge `Unsafe[Mutable]RawPointer as `void [const] *`.
* Parse #dsohandle as UnsafeMutableRawPointer
* Update a bunch of test cases for Void->Raw migration.
* Trivial fix for the SceneKit test case.
* Add an UnsafeRawPointer self initializer.
This is unfortunately necessary for assignment between types imported from C.
* Tiny simplification of the initializer.
We can express the same using the `isUniquelyReferencedNonObjC` API.
- Rename `isUniquelyReferencedNonObjC` to `isKnownUniquelyReferenced`.
- Cleanup `ManagedBufferPointer` by removing holdsUniqueOrPinnedReference` and
renaming `holdsUniqueReference` to `isUniqueReference`.
- No longer promise to return false from `isKnownUniquelyReferenced` for @objc
class instances.
SR-1962
rdar://21886410
* Migrate from `UnsafePointer<Void>` to `UnsafeRawPointer`.
As proposed in SE-0107: UnsafeRawPointer.
`void*` imports as `UnsafeMutableRawPointer`.
`const void*` imports as `UnsafeRawPointer`.
Occurrences of `UnsafePointer<Void>` are replaced with UnsafeRawPointer.
* Migrate overlays from UnsafePointer<Void> to UnsafeRawPointer.
This requires explicit memory binding in several places,
particularly in NSData and CoreAudio.
* Fix a bunch of test cases for Void->Raw migration.
* qsort takes IUO values
* Bridge `Unsafe[Mutable]RawPointer as `void [const] *`.
* Parse #dsohandle as UnsafeMutableRawPointer
* Update a bunch of test cases for Void->Raw migration.
* Trivial fix for the SceneKit test case.
* Add an UnsafeRawPointer self initializer.
This is unfortunately necessary for assignment between types imported from C.
* Tiny simplification of the initializer.
This documentation revision covers a large number of types & protocols:
String, its views and their indices, the Unicode codec types and protocol,
as well as Character, UnicodeScalar, and StaticString, among others.
This also includes a few small changes across the standard library for
consistency.
