These include the pointer-to-pointer and pointer-to-buffer-pointer
initialiser parameters amongst a couple of others, such as
`Unmanaged.fromOpaque`, and the source for the `move[...]` family of
methods.
This fix updates various initializers to handle incoming empty buffers
that happen to have a nil base. They should simply create another
buffer with nil base rather than crashing!
It is valid for an Unsafe[Raw]BufferPointer can have a nil base
address. This allows round-tripping with C code that takes a
pointer/length pair and uses `0` as the pointer value.
The original design wrongly assumed that we would use a sentinel value
for empty buffers and was never updated for or tested with the current
design.
Fixes <rdar://problem/47946984> Regression in Foundation.Data's
UnsafeBufferPointer constructor.
It is unfortunate that `Unsafe[Raw]BufferPointer._pointer` and
`baseAddress` are declared Optional. This leaves extra runtime checks
in the code in the most performance critical paths. Contrast this with
Array, which uses an sentinal pointer for the empty representation.
This forces us to use _unsafelyUnwrappedUnchecked whenever we just
want to dereference a non-empty buffer pointer.
Fixes SR-9809: swiftc appears to make some sub-optimal optimization choices
This fixes the Windows platform, where the aligned allocation path is
not malloc-compatible. It won't have any observable difference on
Darwin or Linux, aside from manually allocated memory on Linux now
being consistently 16-byte aligned (heap objects will still be 8-byte
aligned on Linux).
It is unfortunate that we can't guarantee Swift-allocated memory via
Unsafe*Pointer is malloc compatible on Windows. It would have been
nice for that to be a cross platform guarantee since it's normal to
allocate in C and deallocate in Swift or vice-versa. Now we have to
tell developers to always use _aligned_malloc/_aligned_free when
transitioning between Swift/C if they expect their code to work on
Windows.
Even though this fix isn't required today on Darwin/Linux, it makes
good sense to guarantee that the allocation/deallocation paths are
consistent.
This is done by specifying a constant that stdlib can use to round up
alignment, _swift_MinAllocationAlignment. The runtime asserts that
this constant is greater than MALLOC_ALIGN_MASK for all platforms.
This way, manually allocated buffers will always use the aligned
allocation path. If users specify an alignment less than m
round up so users don't need
to pass the same alignment to deallocate the buffer). This constant
does not need to be ABI.
Alternatives are:
1. Require users of Unsafe*Pointer to specify the same alignment
during deallocation. This is obviously madness.
2. Introduce new runtime entry points:
swift_alignedAlloc/swift_alignedDealloc, introduce corresponding
new builtins, and have Unsafe*Pointer always call those. This would
make the runtime API a little more obvious but would introduce
complexity in other areas of the compiler and it doesn't have any
other significant benefit. Less than 16-byte alignment of manually
allocated buffers on Linux is a non-goal.
Add a use an unchecked subscript on UnsafeBufferPointer, which skips
debugPrecondition checks (in case we're not inlined) as well as a
force-unwrap check.
This switches the standard library's sort algorithm from an in-place
introsort to use a modified timsort, a stable, adaptive sort that
merges runs using a temporary buffer. This implementation performs
straight merges instead of adopting timsort's galloping strategy.
In addition to maintaining the relative order of equal/non-comparable
elements, this algorithm outperforms the introsort on data with any
intrinsic structure, such as runs of ascending or descending elements
or a significant number of equality collisions.
This saves a few instructions for some operations, like getting the count.
Also, it avoids the check for unwrapping the optional end pointer. For example, iterating over an unsafe buffer now has no overhead.
Also remove the _unboundedStartingAt initializer, which is not needed anymore.
* 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
- Revise Equatable and Hashable for synthesized requirements
- Complete Strideable and stride(from:...:by:) documentation
- Revise DoubleWidth type docs
- Add complexity notes for Set.index(of:) and .contains(_:)
- Fix typos in Set.formUnion docs
- Add missing axioms for SetAlgebra (SR-6319)
- Improve guidance for description and debugDescription
- Add note about the result of passing duplicate keys to
Dictionary(uniqueKeysWithValues:)
- Fix typo in BinaryInteger docs
- Update Substring docs with better conversion example
- Improve docs for withMemoryRebound and isKnownUniquelyReferenced
- Add missing docs not propagated from protocols
* Nest various top-level Iterator and Index types, and flatten extensions.
* Fix tests from nesting iterator
* Nest Unsafe*BufferPointer.Iterator, extensionify UnsafeBufferPointer
* Degyb LazyCollection
* Nest Flatten iterator and index
* Eradicate IndexDistance associated type, replacing with Int everywhere
* Consistently use Int for ExistentialCollection’s IndexDistance type.
* Fix test for IndexDistance removal
* Remove a handful of no-longer-needed explicit types
* Add compatibility shims for non-Int index distances
* Test compatibility shim
* Move IndexDistance typealias into the Collection protocol
* Refactor Indices and Slice to use conditional conformance
* Replace ReversedRandomAccessCollection with a conditional extension
* Refactor some types into struct+extensions
* Revise Slice documentation
* Fix test cases for adoption of conditional conformances.
* [RangeReplaceableCollection] Eliminate unnecessary slicing subscript operator.
* Add -enable-experimental-conditional-conformances to test.
* Gruesome workaround for crasher in MutableSlice tests
- Revisions to unsafeDowncast and withVaList
- Fix the Int64/UInt64 discussion
- Buffer pointer revisions
- Fix Optional example to use new integer methods
- Revise and correct some UnsafeRawBufferPointer docs
- Fix symmetricDifference examples
- Fix wording in FloatingPoint.nextDown
- Update ImplicitlyUnwrappedOptional
- Clarify elementsEqual
- Minor integer doc fixes
- Comment for _AppendKeyPath
- Clarification re collection indices
- Revise RangeExpression.relative(to:)
- Codable revisions
* 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
* Add sliceability tests for Unsafe(Raw)BufferPointer.
Improve the generic sliceability tests to verify that SubSequence indices are
compatible with their parents indices.
* Fix and enable testing stdlib Collection instances.
Top-level entry points fully testing a collection instance:
check${Traversal}Collection
One level of recursion into all slices of the collection instance
O(n^2). (Not combinatorial).
Previously, checkCollection() did nothing. So much of the testing infrastructure was inactive. Now it runs all forward collection tests.
Fixes a bug in subscriptRangeTests.
The UnsafeRawBufferPointer and Data collection testing is disabled and
will be fixed in the following commit.
* Give UnsafeRawBufferPointer a distinct slice type.
SubSequence = RandomAccessSlice<Self>
* Fix raw buffer pointer tests after changing the API
* Add UnsafeRawBuffer(rebasing:) initializers.
Allows converting a raw slice into a zero-based raw buffer,
which is a common operation on flat memory.
Add and update UnsafeRawBufferPointer unit tests.
* Do not run recursive O(n^2) collection slice testing on large collections.
Now, even with collection unit testing wired up, the validation tests
take the same amount of time to execute.
* Add init(rebasing:) to UnsafeBufferPointer.
This is required for consistency with UnsafeRawBufferPointer.
* Update CHANGELOG.md for SE-0138 amendment: UnsafeRawBufferPointer slice type.
