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String.swift
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// RUN: %empty-directory(%t)
// RUN: if [ %target-runtime == "objc" ]; \
// RUN: then \
// RUN: %target-clang -fobjc-arc %S/Inputs/NSSlowString/NSSlowString.m -c -o %t/NSSlowString.o && \
// RUN: %target-build-swift -I %S/Inputs/NSSlowString/ %t/NSSlowString.o %s -Xfrontend -disable-access-control -o %t/String -swift-version 3; \
// RUN: else \
// RUN: %target-build-swift %s -Xfrontend -disable-access-control -o %t/String -swift-version 3; \
// RUN: fi
// RUN: %target-run %t/String
// REQUIRES: executable_test
// XFAIL: interpret
// <rdar://problem/41372546> Migrate validation-test/stdlib/String.swift off Swift 3
import StdlibUnittest
import StdlibCollectionUnittest
#if _runtime(_ObjC)
import NSSlowString
import Foundation // For NSRange
#endif
extension Collection {
internal func index(_nth n: Int) -> Index {
precondition(n >= 0)
return index(startIndex, offsetBy: numericCast(n))
}
internal func index(_nthLast n: Int) -> Index {
precondition(n >= 0)
return index(endIndex, offsetBy: -numericCast(n))
}
}
extension String {
var nativeCapacity: Int {
precondition(_guts._isNative)
return _guts.capacity
}
var capacity: Int {
return _guts.capacity
}
var unusedCapacity: Int {
return Swift.max(0, _guts.capacity - _guts.count)
}
var bufferID: ObjectIdentifier? {
return _rawIdentifier()
}
func _rawIdentifier() -> ObjectIdentifier? {
return _guts._objectIdentifier
}
}
extension Substring {
var bufferID: ObjectIdentifier? {
return _wholeString.bufferID
}
}
// A thin wrapper around _StringGuts implementing RangeReplaceableCollection
struct StringGutsCollection: RangeReplaceableCollection, RandomAccessCollection {
typealias Element = UTF16.CodeUnit
typealias Index = Int
typealias Indices = CountableRange<Int>
init(_ guts: _StringGuts) {
self._guts = guts
}
init() {
self.init(_StringGuts())
}
var _guts: _StringGuts
var startIndex: Index { return 0 }
var endIndex: Index { return _guts.count }
var indices: Indices { return startIndex..<endIndex }
subscript(position: Index) -> Element { return _guts[position] }
mutating func replaceSubrange<C>(
_ subrange: Range<Index>,
with newElements: C
) where C : Collection, C.Element == Element {
_guts.replaceSubrange(subrange, with: newElements)
}
mutating func reserveCapacity(_ n: Int) {
_guts.reserveCapacity(n)
}
}
var StringTests = TestSuite("StringTests")
StringTests.test("sizeof") {
#if arch(i386) || arch(arm)
expectEqual(12, MemoryLayout<String>.size)
#else
expectEqual(16, MemoryLayout<String>.size)
#endif
}
StringTests.test("AssociatedTypes-UTF8View") {
typealias View = String.UTF8View
expectCollectionAssociatedTypes(
collectionType: View.self,
iteratorType: View.Iterator.self,
subSequenceType: Substring.UTF8View.self,
indexType: View.Index.self,
indicesType: DefaultIndices<View>.self)
}
StringTests.test("AssociatedTypes-UTF16View") {
typealias View = String.UTF16View
expectCollectionAssociatedTypes(
collectionType: View.self,
iteratorType: IndexingIterator<View>.self,
subSequenceType: Substring.UTF16View.self,
indexType: View.Index.self,
indicesType: View.Indices.self)
}
StringTests.test("AssociatedTypes-UnicodeScalarView") {
typealias View = String.UnicodeScalarView
expectCollectionAssociatedTypes(
collectionType: View.self,
iteratorType: View.Iterator.self,
subSequenceType: Substring.UnicodeScalarView.self,
indexType: View.Index.self,
indicesType: DefaultIndices<View>.self)
}
StringTests.test("AssociatedTypes-CharacterView") {
expectCollectionAssociatedTypes(
collectionType: String.self,
iteratorType: IndexingIterator<String>.self,
subSequenceType: Substring.self,
indexType: String.Index.self,
indicesType: DefaultIndices<String>.self)
}
func checkUnicodeScalarViewIteration(
_ expectedScalars: [UInt32], _ str: String
) {
do {
let us = str.unicodeScalars
var i = us.startIndex
let end = us.endIndex
var decoded: [UInt32] = []
while i != end {
expectTrue(i < us.index(after: i)) // Check for Comparable conformance
decoded.append(us[i].value)
i = us.index(after: i)
}
expectEqual(expectedScalars, decoded)
}
do {
let us = str.unicodeScalars
let start = us.startIndex
var i = us.endIndex
var decoded: [UInt32] = []
while i != start {
i = us.index(before: i)
decoded.append(us[i].value)
}
expectEqual(expectedScalars, decoded)
}
}
StringTests.test("unicodeScalars") {
checkUnicodeScalarViewIteration([], "")
checkUnicodeScalarViewIteration([ 0x0000 ], "\u{0000}")
checkUnicodeScalarViewIteration([ 0x0041 ], "A")
checkUnicodeScalarViewIteration([ 0x007f ], "\u{007f}")
checkUnicodeScalarViewIteration([ 0x0080 ], "\u{0080}")
checkUnicodeScalarViewIteration([ 0x07ff ], "\u{07ff}")
checkUnicodeScalarViewIteration([ 0x0800 ], "\u{0800}")
checkUnicodeScalarViewIteration([ 0xd7ff ], "\u{d7ff}")
checkUnicodeScalarViewIteration([ 0x8000 ], "\u{8000}")
checkUnicodeScalarViewIteration([ 0xe000 ], "\u{e000}")
checkUnicodeScalarViewIteration([ 0xfffd ], "\u{fffd}")
checkUnicodeScalarViewIteration([ 0xffff ], "\u{ffff}")
checkUnicodeScalarViewIteration([ 0x10000 ], "\u{00010000}")
checkUnicodeScalarViewIteration([ 0x10ffff ], "\u{0010ffff}")
}
StringTests.test("Index/Comparable") {
let empty = ""
expectTrue(empty.startIndex == empty.endIndex)
expectFalse(empty.startIndex != empty.endIndex)
expectTrue(empty.startIndex <= empty.endIndex)
expectTrue(empty.startIndex >= empty.endIndex)
expectFalse(empty.startIndex > empty.endIndex)
expectFalse(empty.startIndex < empty.endIndex)
let nonEmpty = "borkus biqualificated"
expectFalse(nonEmpty.startIndex == nonEmpty.endIndex)
expectTrue(nonEmpty.startIndex != nonEmpty.endIndex)
expectTrue(nonEmpty.startIndex <= nonEmpty.endIndex)
expectFalse(nonEmpty.startIndex >= nonEmpty.endIndex)
expectFalse(nonEmpty.startIndex > nonEmpty.endIndex)
expectTrue(nonEmpty.startIndex < nonEmpty.endIndex)
}
StringTests.test("Index/Hashable") {
let s = "abcdef"
let t = Set(s.indices)
expectEqual(s.count, t.count)
expectTrue(t.contains(s.startIndex))
}
StringTests.test("ForeignIndexes/Valid") {
// It is actually unclear what the correct behavior is. This test is just a
// change detector.
//
// <rdar://problem/18037897> Design, document, implement invalidation model
// for foreign String indexes
do {
let donor = "abcdef"
let acceptor = "uvwxyz"
expectEqual("u", acceptor[donor.startIndex])
expectEqual("wxy",
acceptor[donor.index(_nth: 2)..<donor.index(_nth: 5)])
}
do {
let donor = "abcdef"
let acceptor = "\u{1f601}\u{1f602}\u{1f603}"
expectEqual("\u{1f601}", acceptor[donor.startIndex])
expectEqual("\u{fffd}", acceptor[donor.index(after: donor.startIndex)])
expectEqualUnicodeScalars([ 0xfffd, 0x1f602, 0xfffd ],
acceptor[donor.index(_nth: 1)..<donor.index(_nth: 5)])
expectEqualUnicodeScalars([ 0x1f602, 0xfffd ],
acceptor[donor.index(_nth: 2)..<donor.index(_nth: 5)])
}
}
StringTests.test("ForeignIndexes/UnexpectedCrash")
.xfail(
.always("<rdar://problem/18029290> String.Index caches the grapheme " +
"cluster size, but it is not always correct to use"))
.code {
let donor = "\u{1f601}\u{1f602}\u{1f603}"
let acceptor = "abcdef"
// Adjust donor.startIndex to ensure it caches a stride
let start = donor.index(before: donor.index(after: donor.startIndex))
// FIXME: this traps right now when trying to construct Character("ab").
expectEqual("a", acceptor[start])
}
StringTests.test("ForeignIndexes/subscript(Index)/OutOfBoundsTrap") {
let donor = "abcdef"
let acceptor = "uvw"
expectEqual("u", acceptor[donor.index(_nth: 0)])
expectEqual("v", acceptor[donor.index(_nth: 1)])
expectEqual("w", acceptor[donor.index(_nth: 2)])
let i = donor.index(_nth: 3)
expectCrashLater()
_ = acceptor[i]
}
StringTests.test("String/subscript(_:Range)") {
let s = "foobar"
let from = s.startIndex
let to = s.index(before: s.endIndex)
let actual = s[from..<to]
expectEqual("fooba", actual)
}
StringTests.test("String/subscript(_:ClosedRange)") {
let s = "foobar"
let from = s.startIndex
let to = s.index(before: s.endIndex)
let actual = s[from...to]
expectEqual(s, actual)
}
StringTests.test("ForeignIndexes/subscript(Range)/OutOfBoundsTrap/1") {
let donor = "abcdef"
let acceptor = "uvw"
expectEqual("uvw", acceptor[donor.startIndex..<donor.index(_nth: 3)])
let r = donor.startIndex..<donor.index(_nth: 4)
expectCrashLater()
_ = acceptor[r]
}
StringTests.test("ForeignIndexes/subscript(Range)/OutOfBoundsTrap/2") {
let donor = "abcdef"
let acceptor = "uvw"
expectEqual("uvw", acceptor[donor.startIndex..<donor.index(_nth: 3)])
let r = donor.index(_nth: 4)..<donor.index(_nth: 5)
expectCrashLater()
_ = acceptor[r]
}
StringTests.test("ForeignIndexes/subscript(ClosedRange)/OutOfBoundsTrap/1") {
let donor = "abcdef"
let acceptor = "uvw"
expectEqual("uvw", acceptor[donor.startIndex...donor.index(_nth: 2)])
let r = donor.startIndex...donor.index(_nth: 3)
expectCrashLater()
_ = acceptor[r]
}
StringTests.test("ForeignIndexes/subscript(ClosedRange)/OutOfBoundsTrap/2") {
let donor = "abcdef"
let acceptor = "uvw"
expectEqual("uvw", acceptor[donor.startIndex...donor.index(_nth: 2)])
let r = donor.index(_nth: 3)...donor.index(_nth: 5)
expectCrashLater()
_ = acceptor[r]
}
StringTests.test("ForeignIndexes/replaceSubrange/OutOfBoundsTrap/1") {
let donor = "abcdef"
var acceptor = "uvw"
acceptor.replaceSubrange(
donor.startIndex..<donor.index(_nth: 1), with: "u")
expectEqual("uvw", acceptor)
let r = donor.startIndex..<donor.index(_nth: 4)
expectCrashLater()
acceptor.replaceSubrange(r, with: "")
}
StringTests.test("ForeignIndexes/replaceSubrange/OutOfBoundsTrap/2") {
let donor = "abcdef"
var acceptor = "uvw"
acceptor.replaceSubrange(
donor.startIndex..<donor.index(_nth: 1), with: "u")
expectEqual("uvw", acceptor)
let r = donor.index(_nth: 4)..<donor.index(_nth: 5)
expectCrashLater()
acceptor.replaceSubrange(r, with: "")
}
StringTests.test("ForeignIndexes/removeAt/OutOfBoundsTrap") {
do {
let donor = "abcdef"
var acceptor = "uvw"
let removed = acceptor.remove(at: donor.startIndex)
expectEqual("u", removed)
expectEqual("vw", acceptor)
}
let donor = "abcdef"
var acceptor = "uvw"
let i = donor.index(_nth: 4)
expectCrashLater()
acceptor.remove(at: i)
}
StringTests.test("ForeignIndexes/removeSubrange/OutOfBoundsTrap/1") {
do {
let donor = "abcdef"
var acceptor = "uvw"
acceptor.removeSubrange(
donor.startIndex..<donor.index(after: donor.startIndex))
expectEqual("vw", acceptor)
}
let donor = "abcdef"
var acceptor = "uvw"
let r = donor.startIndex..<donor.index(_nth: 4)
expectCrashLater()
acceptor.removeSubrange(r)
}
StringTests.test("ForeignIndexes/removeSubrange/OutOfBoundsTrap/2") {
let donor = "abcdef"
var acceptor = "uvw"
let r = donor.index(_nth: 4)..<donor.index(_nth: 5)
expectCrashLater()
acceptor.removeSubrange(r)
}
StringTests.test("hasPrefix")
.skip(.nativeRuntime("String.hasPrefix undefined without _runtime(_ObjC)"))
.code {
#if _runtime(_ObjC)
expectTrue("".hasPrefix(""))
expectFalse("".hasPrefix("a"))
expectTrue("a".hasPrefix(""))
expectTrue("a".hasPrefix("a"))
// U+0301 COMBINING ACUTE ACCENT
// U+00E1 LATIN SMALL LETTER A WITH ACUTE
expectFalse("abc".hasPrefix("a\u{0301}"))
expectFalse("a\u{0301}bc".hasPrefix("a"))
expectTrue("\u{00e1}bc".hasPrefix("a\u{0301}"))
expectTrue("a\u{0301}bc".hasPrefix("\u{00e1}"))
#else
expectUnreachable()
#endif
}
StringTests.test("literalConcatenation") {
do {
// UnicodeScalarLiteral + UnicodeScalarLiteral
var s = "1" + "2"
expectType(String.self, &s)
expectEqual("12", s)
}
do {
// UnicodeScalarLiteral + ExtendedGraphemeClusterLiteral
var s = "1" + "a\u{0301}"
expectType(String.self, &s)
expectEqual("1a\u{0301}", s)
}
do {
// UnicodeScalarLiteral + StringLiteral
var s = "1" + "xyz"
expectType(String.self, &s)
expectEqual("1xyz", s)
}
do {
// ExtendedGraphemeClusterLiteral + UnicodeScalar
var s = "a\u{0301}" + "z"
expectType(String.self, &s)
expectEqual("a\u{0301}z", s)
}
do {
// ExtendedGraphemeClusterLiteral + ExtendedGraphemeClusterLiteral
var s = "a\u{0301}" + "e\u{0302}"
expectType(String.self, &s)
expectEqual("a\u{0301}e\u{0302}", s)
}
do {
// ExtendedGraphemeClusterLiteral + StringLiteral
var s = "a\u{0301}" + "xyz"
expectType(String.self, &s)
expectEqual("a\u{0301}xyz", s)
}
do {
// StringLiteral + UnicodeScalar
var s = "xyz" + "1"
expectType(String.self, &s)
expectEqual("xyz1", s)
}
do {
// StringLiteral + ExtendedGraphemeClusterLiteral
var s = "xyz" + "a\u{0301}"
expectType(String.self, &s)
expectEqual("xyza\u{0301}", s)
}
do {
// StringLiteral + StringLiteral
var s = "xyz" + "abc"
expectType(String.self, &s)
expectEqual("xyzabc", s)
}
}
StringTests.test("substringDoesNotCopy/Swift3")
.xfail(.always("Swift 3 compatibility: Self-sliced Strings are copied"))
.code {
let size = 16
for sliceStart in [0, 2, 8, size] {
for sliceEnd in [0, 2, 8, sliceStart + 1] {
if sliceStart > size || sliceEnd > size || sliceEnd < sliceStart {
continue
}
var s0 = String(repeating: "x", count: size)
let originalIdentity = s0.bufferID
s0 = s0[s0.index(_nth: sliceStart)..<s0.index(_nth: sliceEnd)]
expectEqual(originalIdentity, s0.bufferID)
}
}
}
StringTests.test("substringDoesNotCopy/Swift4") {
let size = 16
for sliceStart in [0, 2, 8, size] {
for sliceEnd in [0, 2, 8, sliceStart + 1] {
if sliceStart > size || sliceEnd > size || sliceEnd < sliceStart {
continue
}
let s0 = String(repeating: "x", count: size)
let originalIdentity = s0.bufferID
let s1 = Substring(
_base: s0,
s0.index(_nth: sliceStart)..<s0.index(_nth: sliceEnd))
expectEqual(s1.bufferID, originalIdentity)
}
}
}
StringTests.test("appendToEmptyString") {
let x = "Bumfuzzle"
expectNil(x.bufferID)
// Appending to empty string literal should replace it.
var a1 = ""
a1 += x
expectNil(a1.bufferID)
// Appending to native string should keep the existing buffer.
var b1 = ""
b1.reserveCapacity(20)
let b1ID = b1.bufferID
b1 += x
expectEqual(b1.bufferID, b1ID)
// .append(_:) should have the same behavior as +=
var a2 = ""
a2.append(x)
expectNil(a2.bufferID)
var b2 = ""
b2.reserveCapacity(20)
let b2ID = b2.bufferID
b2.append(x)
expectEqual(b2.bufferID, b2ID)
}
StringTests.test("Swift3Slice/Empty") {
let size = 5
let s = String(repeating: "x", count: size)
for i in 0 ... size {
let slice = s[s.index(_nth: i)..<s.index(_nth: i)]
// Most Swift 3 substrings are extracted into their own buffer,
// but empty substrings get turned into the empty string singleton
expectNil(slice.bufferID)
}
}
StringTests.test("Swift3Slice/Full") {
let size = 5
let s = String(repeating: "x", count: size)
let slice = s[s.startIndex..<s.endIndex]
// Most Swift 3 substrings are extracted into their own buffer,
// but if the substring covers the full original string, it is used instead.
expectEqual(slice.bufferID, s.bufferID)
}
StringTests.test("appendToSubstring") {
for initialSize in 1..<16 {
for sliceStart in [0, 2, 8, initialSize] {
for sliceEnd in [0, 2, 8, sliceStart + 1] {
if sliceStart > initialSize || sliceEnd > initialSize ||
sliceEnd < sliceStart {
continue
}
var s0 = String(repeating: "x", count: initialSize)
s0 = s0[s0.index(_nth: sliceStart)..<s0.index(_nth: sliceEnd)]
s0 += "x"
expectEqual(
String(
repeating: "x",
count: sliceEnd - sliceStart + 1),
s0)
}
}
}
}
StringTests.test("appendToSubstringBug")
.xfail(.always("Swift 3 compatibility: Self-sliced Strings are copied"))
.code {
// String used to have a heap overflow bug when one attempted to append to a
// substring that pointed to the end of a string buffer.
//
// Unused capacity
// VVV
// String buffer [abcdefghijk ]
// ^ ^
// +----+
// Substring -----------+
//
// In the example above, there are only three elements of unused capacity.
// The bug was that the implementation mistakenly assumed 9 elements of
// unused capacity (length of the prefix "abcdef" plus truly unused elements
// at the end).
func stringWithUnusedCapacity() -> (String, Int) {
var s0 = String(repeating: "x", count: 17)
if s0.unusedCapacity == 0 { s0 += "y" }
let cap = s0.unusedCapacity
expectNotEqual(0, cap)
// This sorta checks for the original bug
expectEqual(
cap, s0[s0.index(_nth: 1)..<s0.endIndex].unusedCapacity)
return (s0, cap)
}
do {
var (s, _) = { ()->(String, Int) in
let (s0, unused) = stringWithUnusedCapacity()
return (s0[s0.index(_nth: 5)..<s0.endIndex], unused)
}()
let originalID = s.bufferID
// Appending to a String always results in storage that
// starts at the beginning of its native buffer
s += "z"
expectNotEqual(originalID, s.bufferID)
}
do {
var (s, _) = { ()->(Substring, Int) in
let (s0, unused) = stringWithUnusedCapacity()
return (s0[s0.index(_nth: 5)..<s0.endIndex], unused)
}()
let originalID = s.bufferID
// FIXME: Ideally, appending to a Substring with a unique buffer reference
// does not reallocate unless necessary. Today, however, it appears to do
// so unconditionally unless the slice falls at the beginning of its buffer.
s += "z"
expectNotEqual(originalID, s.bufferID)
}
// Try again at the beginning of the buffer
do {
var (s, unused) = { ()->(Substring, Int) in
let (s0, unused) = stringWithUnusedCapacity()
return (s0[...], unused)
}()
let originalID = s.bufferID
s += "z"
expectEqual(originalID, s.bufferID)
s += String(repeating: "z", count: unused - 1)
expectEqual(originalID, s.bufferID)
s += "."
expectNotEqual(originalID, s.bufferID)
unused += 0 // warning suppression
}
}
StringTests.test("COW/removeSubrange/start") {
var str = "12345678"
let literalIdentity = str.bufferID
// Check literal-to-heap reallocation.
do {
let slice = str
expectEqual(literalIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("12345678", str)
expectEqual("12345678", slice)
// This mutation should reallocate the string.
str.removeSubrange(str.startIndex..<str.index(_nth: 1))
expectNotEqual(literalIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
let heapStrIdentity = str.bufferID
expectEqual("2345678", str)
expectEqual("12345678", slice)
// No more reallocations are expected.
str.removeSubrange(str.startIndex..<str.index(_nth: 1))
expectEqual(heapStrIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("345678", str)
expectEqual("12345678", slice)
}
// Check heap-to-heap reallocation.
expectEqual("345678", str)
do {
let heapStrIdentity1 = str.bufferID
let slice = str
expectEqual(heapStrIdentity1, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
expectEqual("345678", str)
expectEqual("345678", slice)
// This mutation should reallocate the string.
str.removeSubrange(str.startIndex..<str.index(_nth: 1))
expectNotEqual(heapStrIdentity1, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
let heapStrIdentity2 = str.bufferID
expectEqual("45678", str)
expectEqual("345678", slice)
// No more reallocations are expected.
str.removeSubrange(str.startIndex..<str.index(_nth: 1))
expectEqual(heapStrIdentity2, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
expectEqual("5678", str)
expectEqual("345678", slice)
}
}
StringTests.test("COW/removeSubrange/end") {
var str = "12345678"
let literalIdentity = str.bufferID
// Check literal-to-heap reallocation.
expectEqual("12345678", str)
do {
let slice = str
expectEqual(literalIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("12345678", str)
expectEqual("12345678", slice)
// This mutation should reallocate the string.
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectNotEqual(literalIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
let heapStrIdentity = str.bufferID
expectEqual("1234567", str)
expectEqual("12345678", slice)
// No more reallocations are expected.
str.append("x")
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectEqual(heapStrIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("1234567", str)
expectEqual("12345678", slice)
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
str.append("x")
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectEqual(heapStrIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("123456", str)
expectEqual("12345678", slice)
}
// Check heap-to-heap reallocation.
expectEqual("123456", str)
do {
let heapStrIdentity1 = str.bufferID
let slice = str
expectEqual(heapStrIdentity1, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
expectEqual("123456", str)
expectEqual("123456", slice)
// This mutation should reallocate the string.
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectNotEqual(heapStrIdentity1, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
let heapStrIdentity = str.bufferID
expectEqual("12345", str)
expectEqual("123456", slice)
// No more reallocations are expected.
str.append("x")
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectEqual(heapStrIdentity, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
expectEqual("12345", str)
expectEqual("123456", slice)
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
str.append("x")
str.removeSubrange(str.index(_nthLast: 1)..<str.endIndex)
expectEqual(heapStrIdentity, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
expectEqual("1234", str)
expectEqual("123456", slice)
}
}
StringTests.test("COW/replaceSubrange/end") {
// Check literal-to-heap reallocation.
do {
let str = "12345678"
let literalIdentity = str.bufferID
var slice = str[str.startIndex..<str.index(_nth: 7)]
expectEqual(literalIdentity, str.bufferID)
expectEqual(literalIdentity, slice.bufferID)
expectEqual("12345678", str)
expectEqual("1234567", slice)
// This mutation should reallocate the string.
slice.replaceSubrange(slice.endIndex..<slice.endIndex, with: "a")
expectNotEqual(literalIdentity, slice.bufferID)
expectEqual(literalIdentity, str.bufferID)
let heapStrIdentity = slice.bufferID
expectEqual("1234567a", slice)
expectEqual("12345678", str)
// No more reallocations are expected.
slice.replaceSubrange(
slice.index(_nthLast: 1)..<slice.endIndex, with: "b")
expectEqual(heapStrIdentity, slice.bufferID)
expectEqual(literalIdentity, str.bufferID)
expectEqual("1234567b", slice)
expectEqual("12345678", str)
}
// Check literal-to-heap reallocation.
do {
var str = "12345678"
let literalIdentity = str.bufferID
// Move the string to the heap.
str.reserveCapacity(32)
expectNotEqual(literalIdentity, str.bufferID)
let heapStrIdentity1 = str.bufferID
// FIXME: We have to use Swift 4's Substring to get the desired storage
// semantics; in Swift 3 mode, self-sliced strings get allocated a new
// buffer immediately.
var slice = Substring(_base: str, str.startIndex..<str.index(_nth: 7))
expectEqual(heapStrIdentity1, str.bufferID)
expectEqual(heapStrIdentity1, slice.bufferID)
// This mutation should reallocate the string.
slice.replaceSubrange(slice.endIndex..<slice.endIndex, with: "a")
expectNotEqual(heapStrIdentity1, slice.bufferID)
expectEqual(heapStrIdentity1, str.bufferID)
let heapStrIdentity2 = slice.bufferID
expectEqual("1234567a", slice)
expectEqual("12345678", str)
// No more reallocations are expected.
slice.replaceSubrange(
slice.index(_nthLast: 1)..<slice.endIndex, with: "b")
expectEqual(heapStrIdentity2, slice.bufferID)
expectEqual(heapStrIdentity1, str.bufferID)
expectEqual("1234567b", slice)
expectEqual("12345678", str)
}
}
func asciiString<
S: Sequence
>(_ content: S) -> String
where S.Iterator.Element == Character {
var s = String()
s.append(contentsOf: content)
expectTrue(s._guts.isSingleByte)
return s
}
StringTests.test("stringGutsExtensibility")
.skip(.nativeRuntime("Foundation dependency"))
.code {
#if _runtime(_ObjC)
let ascii = UTF16.CodeUnit(UnicodeScalar("X").value)
let nonAscii = UTF16.CodeUnit(UnicodeScalar("é").value)
for k in 0..<3 {
for count in 1..<16 {
for boundary in 0..<count {
var x = (
k == 0 ? asciiString("b")
: k == 1 ? ("b" as NSString as String)
: ("b" as NSMutableString as String)
)._guts
if k == 0 { expectTrue(x.isSingleByte) }
for i in 0..<count {
x.append(contentsOf:
repeatElement(i < boundary ? ascii : nonAscii, count: 3))
}
// Make sure we can append pure ASCII to wide storage
x.append(contentsOf: repeatElement(ascii, count: 2))
expectEqualSequence(
[UTF16.CodeUnit(UnicodeScalar("b").value)]
+ Array(repeatElement(ascii, count: 3*boundary))
+ repeatElement(nonAscii, count: 3*(count - boundary))
+ repeatElement(ascii, count: 2),
StringGutsCollection(x)
)
}
}
}
#else
expectUnreachable()
#endif
}
StringTests.test("stringGutsReserve")
.skip(.nativeRuntime("Foundation dependency"))
.code {
#if _runtime(_ObjC)
for k in 0...7 {
var base: String
var startedNative: Bool
let shared: String = "X"
// Managed native, unmanaged native, or small
func isSwiftNative(_ s: String) -> Bool {
return s._guts._isNative || s._guts._isSmall || s._guts._isUnmanaged
}
switch k {
case 0: (base, startedNative) = (String(), true)
case 1: (base, startedNative) = (asciiString("x"), true)
case 2: (base, startedNative) = ("Ξ", true)
#if arch(i386) || arch(arm)
case 3: (base, startedNative) = ("x" as NSString as String, false)
case 4: (base, startedNative) = ("x" as NSMutableString as String, false)
#else
case 3: (base, startedNative) = ("x" as NSString as String, true)
case 4: (base, startedNative) = ("x" as NSMutableString as String, true)
#endif
case 5: (base, startedNative) = (shared, true)
case 6: (base, startedNative) = ("xá" as NSString as String, false)
case 7: (base, startedNative) = ("xá" as NSMutableString as String, false)
default:
fatalError("case unhandled!")
}
expectEqual(isSwiftNative(base), startedNative)
let originalBuffer = base.bufferID
let isUnique = base._guts._isUniqueNative()
let startedUnique =
startedNative &&
base._guts._objectIdentifier != nil &&
isUnique
base.reserveCapacity(16)
// Now it's unique
// If it was already native and unique, no reallocation
if startedUnique && startedNative {
expectEqual(originalBuffer, base.bufferID)
}
else {
expectNotEqual(originalBuffer, base.bufferID)
}
// Reserving up to the capacity in a unique native buffer is a no-op
let nativeBuffer = base.bufferID
let currentCapacity = base.capacity
base.reserveCapacity(currentCapacity)
expectEqual(nativeBuffer, base.bufferID)
// Reserving more capacity should reallocate
base.reserveCapacity(currentCapacity + 1)
expectNotEqual(nativeBuffer, base.bufferID)
// None of this should change the string contents
var expected: String
switch k {
case 0: expected = ""
case 1,3,4: expected = "x"
case 2: expected = "Ξ"
case 5: expected = shared
case 6,7: expected = "xá"
default:
fatalError("case unhandled!")
}
expectEqual(expected, base)
}
#else
expectUnreachable()
#endif
}
func makeStringGuts(_ base: String) -> _StringGuts {
var x = _StringGuts()
// make sure some - but not all - replacements will have to grow the buffer
x.reserveCapacity(base._guts.count * 3 / 2)
let capacity = x.capacity
x.append(base._guts)
// Widening the guts should not make it lose its capacity,
// but the allocator may decide to get more storage.
expectGE(x.capacity, capacity)
return x
}
StringTests.test("StringGutsReplace") {
let narrow = "01234567890"
let wide = "ⅠⅡⅢⅣⅤⅥⅦⅧⅨⅩⅪ"
for s1 in [narrow, wide] {
for s2 in [narrow, wide] {
let g1 = makeStringGuts(s1)
let g2 = makeStringGuts(s2 + s2)
checkRangeReplaceable(