https://github.com/swiftlang/swift/pull/72612 can be reverted because it is no
longer necessary for the interface of the stdlib to be compatible with
compilers without `$TypedThrows` support.
Functions that are used in public `@inlinable` function bodies can't be marked
`@_spi` nor can they be made obsolete. Also, they must retain `rethrows` so
that use of these entry points from other `rethrows` functions is accepted.
Builds on https://github.com/apple/swift/pull/72365. Once we no longer have to
support pre-`$TypedThrows` compilers, all of this can be reverted.
Part of rdar://125138945
This isn't a "complete" port of the standard library for embedded Swift, but
something that should serve as a starting point for further iterations on the
stdlib.
- General CMake logic for building a library as ".swiftmodule only" (ONLY_SWIFTMODULE).
- CMake logic in stdlib/public/core/CMakeLists.txt to start building the embedded stdlib for a handful of hardcoded target triples.
- Lots of annotations throughout the standard library to make types, functions, protocols unavailable in embedded Swift (@_unavailableInEmbedded).
- Mainly this is about stdlib functionality that relies on existentials, type erasure, metatypes, reflection, string interpolations.
- We rely on function body removal of unavailable functions to eliminate the actual problematic SIL code (existentials).
- Many .swift files are not included in the compilation of embedded stdlib at all, to simplify the scope of the annotations.
- EmbeddedStubs.swift is used to stub out (as unavailable and fatalError'd) the missing functionality.
`String.debugDescription` currently fails to protect the contents of
the string from combining with the opening or closing `”` characters
or one of the characters of a quoted scalar:
```swift
let s = “\u{301}A\n\u{302}B\u{70F}”
print(s.debugDescription)
// ⟹ “́A\n̂B” (characters: “́, A, \, n̂, B, ”)
```
This can make debug output difficult to read, as string contents are
allowed to spread over and pollute neighboring meta-characters.
This change fixes this by force-quoting the problematic scalars in
these cases:
```swift
let s = “\u{301}A\n\u{302}B\u{70F}”
print(s.debugDescription)
// ⟹ “\u{301}A\n\u{302}B\u{70F}”
```
Of course, Unicode scalars that don’t engage in such behavior are
still allowed to pass through unchanged:
```swift
let s = “Cafe\u{301}”
print(s.debugDescription)
// ⟹ “Café”
```
We trust the internal implementation of the stdlib to not cause any unintentional buffer overflows.
In such cases we can use the "unprotected" address-to-pointer conversions.
This avoids inserting stack protections where it's not needed.
Introduce checking of ConcurrentValue conformances:
- For structs, check that each stored property conforms to ConcurrentValue
- For enums, check that each associated value conforms to ConcurrentValue
- For classes, check that each stored property is immutable and conforms
to ConcurrentValue
Because all of the stored properties / associated values need to be
visible for this check to work, limit ConcurrentValue conformances to
be in the same source file as the type definition.
This checking can be disabled by conforming to a new marker protocol,
UnsafeConcurrentValue, that refines ConcurrentValue.
UnsafeConcurrentValue otherwise his no specific meaning. This allows
both "I know what I'm doing" for types that manage concurrent access
themselves as well as enabling retroactive conformance, both of which
are fundamentally unsafe but also quite necessary.
The bulk of this change ended up being to the standard library, because
all conformances of standard library types to the ConcurrentValue
protocol needed to be sunk down into the standard library so they
would benefit from the checking above. There were numerous little
mistakes in the initial pass through the stsandard library types that
have now been corrected.
* Replace stdlib and test/stdlib 9999 availability.
macOS 9999 -> macOS 10.15
iOS 9999 -> iOS 13
tvOS 9999 -> tvOS 13
watchOS 9999 -> watchOS 6
* Restore the pre-10.15 version of public init?(_: NSRange, in: __shared String)
We need this to allow master to work on 10.14 systems (in particular, to allow PR testing to work correctly without disabling back-deployment tests).
Since scalar-alignment is set in inlinable code, switch the alignment
bit to one of the previously-reserved bits rather than a grapheme
cache bit. Setting a grapheme cache bit in inlinable would break
backward deployment, as older versions would interpret it as a cached
value.
Also adjust the name to "scalar-aligned", which is clearer, and
removed assertion (which should be a real precondition).
Fixes a general category (pun intended) of scalar-alignment bugs
surrounding exchanging non-scalar-aligned indices between views and
for slicing.
SE-0180 unifies the Index type of String and all its views and allows
non-scalar-aligned indices to be used across views. In order to
guarantee behavior, we often have to check and perform scalar
alignment. To speed up these checks, we allocate a bit denoting
known-to-be-aligned, so that the alignment check can skip the
load. The below shows what views need to check for alignment before
they can operate, and whether the indices they produce are aligned.
┌───────────────╥────────────────────┬──────────────────────────┐
│ View ║ Requires Alignment │ Produces Aligned Indices │
╞═══════════════╬════════════════════╪══════════════════════════╡
│ Native UTF8 ║ no │ no │
├───────────────╫────────────────────┼──────────────────────────┤
│ Native UTF16 ║ yes │ no │
╞═══════════════╬════════════════════╪══════════════════════════╡
│ Foreign UTF8 ║ yes │ no │
├───────────────╫────────────────────┼──────────────────────────┤
│ Foreign UTF16 ║ no │ no │
╞═══════════════╬════════════════════╪══════════════════════════╡
│ UnicodeScalar ║ yes │ yes │
├───────────────╫────────────────────┼──────────────────────────┤
│ Character ║ yes │ yes │
└───────────────╨────────────────────┴──────────────────────────┘
The "requires alignment" applies to any operation taking a
String.Index that's not defined entirely in terms of other operations
taking a String.Index. These include:
* index(after:)
* index(before:)
* subscript
* distance(from:to:) (since `to` is compared against directly)
* UTF16View._nativeGetOffset(for:)
This adds new (availability-controlled) API to Unicode.Scalar,
exposing the scalar's UTF-8 code units as a random-access collection
similarly to how it currently exposes UTF-16 code units.
Tests added.
We need to explicity ensure that an integer is in the required byte
order (little-endian in this case) before accessing it as an array
of bytes through an unsafe pointer.
As a general rule, it is safe to mark the implementation of hash(into:) and _rawHashValue(seed:) for @_fixed_layout structs as inlinable.
However, some structs (like String guts, Character, KeyPath-related types) have complicated enough hashing that it seems counterproductive to inline them. Mark these with @effects(releasenone) instead.
This includes various revisions to the APIs landing in Swift 4.2, including:
- Random and other randomness APIs
- Hashable changes
- MemoryLayout.offset(of:)
Streamline internal String creation. Previously, everything funneled
into a single generic function, however, every single call of the
generic funnel had relevant specific information that could be used
for a more efficient algorithm.
In preparation for efficiently forming small strings, refactor this
logic into a handful of more specialized subroutines to preserve more
specific information from the callers.
* 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
Include the initial implementation of _StringGuts, a 2-word
replacement for _LegacyStringCore. 64-bit Darwin supported, 32-bit and
Linux support in subsequent commits.
- Update NSRange -> Range guidance
- Fix example in Optional
- Improve RangeExpression docs
- Fix issue in UnsafeRawBufferPointer.initializeMemory
- Code point -> scalar value most places
- Reposition the dot above the scripty `i'
- Fix ExpressibleByArrayLiteral code sample
Piggybacks some resilience diagnostics onto the availability
checking code.
Public and versioned functions with inlineable bodies can only
reference other public and internal entities, since the SIL code
for the function body is serialized and stored as part of the
module.
This includes @_transparent functions, @_inlineable functions,
accessors for @_inlineable storage, @inline(__always) functions,
and in Swift 4 mode, default argument expressions.
The new checks are a source-breaking change, however we don't
guarantee source compatibility for underscored attributes.
The new ABI and tests for the default argument model will come in
subsequent commits.
