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Use UnsafeRawPointer in StringCore.

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This is another necessary step in introducing changes
for SE-0107: UnsafeRawPointer.

UnsafeRawPointer is great for bytewise pointer operations.

OpaquePointer goes away.

The _RawByte type goes away.

StringBuffer always binds memory to the correct CodeUnit
when allocating memory.

Before accessing the string, a dynamic element width check
allows us to assume the bound memory type.

Generic entry points like atomicCompareExchange no longer handle
both kinds of pointers. Normally that's good because you
should not be using generics in that case, just upcast
to raw pointer. However, with pointers-to-pointers
you can't do that.
This commit is contained in:
Andrew Trick
2016-07-26 18:28:39 -07:00
parent 3e2372b6a3
commit 9886e4ef54
12 changed files with 133 additions and 119 deletions
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40
stdlib/public/core/String.swift
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@@ -400,7 +400,7 @@ extension String : _ExpressibleByBuiltinUTF16StringLiteral {
) {
self = String(
_StringCore(
baseAddress: OpaquePointer(start),
baseAddress: UnsafeMutableRawPointer(start),
count: Int(utf16CodeUnitCount),
elementShift: 1,
hasCocoaBuffer: false,
@@ -418,7 +418,7 @@ extension String : _ExpressibleByBuiltinStringLiteral {
if Bool(isASCII) {
self = String(
_StringCore(
baseAddress: OpaquePointer(start),
baseAddress: UnsafeMutableRawPointer(start),
count: Int(utf8CodeUnitCount),
elementShift: 0,
hasCocoaBuffer: false,
@@ -699,13 +699,15 @@ extension String : Hashable {
}
#else
if self._core.isASCII {
return _swift_stdlib_unicode_hash_ascii(
UnsafeMutablePointer<Int8>(_core.startASCII),
Int32(_core.count))
return _core.startASCII.withMemoryRebound(
to: CChar.self, capacity: _core.count) {
_swift_stdlib_unicode_hash_ascii($0, Int32(_core.count))
}
} else {
return _swift_stdlib_unicode_hash(
UnsafeMutablePointer<UInt16>(_core.startUTF16),
Int32(_core.count))
return _core.startUTF16.withMemoryRebound(
to: UInt16.self, capacity: _core.count) {
_swift_stdlib_unicode_hash($0, Int32(_core.count))
}
}
#endif
}
@@ -821,7 +823,8 @@ internal func _nativeUnicodeLowercaseString(_ str: String) -> String {
capacity: str._core.count, initialSize: str._core.count, elementWidth: 2)
// Try to write it out to the same length.
let dest = UnsafeMutablePointer<UTF16.CodeUnit>(buffer.start)
let dest = buffer.start.bindMemory(
to: UTF16.CodeUnit.self, capacity: str._core.count)
let z = _swift_stdlib_unicode_strToLower(
dest, Int32(str._core.count),
str._core.startUTF16, Int32(str._core.count))
@@ -831,7 +834,8 @@ internal func _nativeUnicodeLowercaseString(_ str: String) -> String {
if correctSize != str._core.count {
buffer = _StringBuffer(
capacity: correctSize, initialSize: correctSize, elementWidth: 2)
let dest = UnsafeMutablePointer<UTF16.CodeUnit>(buffer.start)
let dest = buffer.start.bindMemory(
to: UTF16.CodeUnit.self, capacity: str._core.count)
_swift_stdlib_unicode_strToLower(
dest, Int32(correctSize), str._core.startUTF16, Int32(str._core.count))
}
@@ -844,7 +848,8 @@ internal func _nativeUnicodeUppercaseString(_ str: String) -> String {
capacity: str._core.count, initialSize: str._core.count, elementWidth: 2)
// Try to write it out to the same length.
let dest = UnsafeMutablePointer<UTF16.CodeUnit>(buffer.start)
let dest = buffer.start.bindMemory(
to: UTF16.CodeUnit.self, capacity: str._core.count)
let z = _swift_stdlib_unicode_strToUpper(
dest, Int32(str._core.count),
str._core.startUTF16, Int32(str._core.count))
@@ -854,7 +859,8 @@ internal func _nativeUnicodeUppercaseString(_ str: String) -> String {
if correctSize != str._core.count {
buffer = _StringBuffer(
capacity: correctSize, initialSize: correctSize, elementWidth: 2)
let dest = UnsafeMutablePointer<UTF16.CodeUnit>(buffer.start)
let dest = buffer.start.bindMemory(
to: UTF16.CodeUnit.self, capacity: str._core.count)
_swift_stdlib_unicode_strToUpper(
dest, Int32(correctSize), str._core.startUTF16, Int32(str._core.count))
}
@@ -904,7 +910,7 @@ extension String {
let source = self._core.startASCII
let buffer = _StringBuffer(
capacity: count, initialSize: count, elementWidth: 1)
let dest = UnsafeMutablePointer<UInt8>(buffer.start)
let dest = buffer.start
for i in 0..<count {
// For each character in the string, we lookup if it should be shifted
// in our ascii table, then we return 0x20 if it should, 0x0 if not.
@@ -923,7 +929,8 @@ extension String {
// Since we are left with either 0x0 or 0x20, we can safely truncate to
// a UInt8 and add to our ASCII value (this will not overflow numbers in
// the ASCII range).
dest[i] = value &+ UInt8(truncatingBitPattern: add)
dest.storeBytes(of: value &+ UInt8(truncatingBitPattern: add),
toByteOffset: i, as: UInt8.self)
}
return String(_storage: buffer)
}
@@ -953,7 +960,7 @@ extension String {
let source = self._core.startASCII
let buffer = _StringBuffer(
capacity: count, initialSize: count, elementWidth: 1)
let dest = UnsafeMutablePointer<UInt8>(buffer.start)
let dest = buffer.start
for i in 0..<count {
// See the comment above in lowercaseString.
let value = source[i]
@@ -961,7 +968,8 @@ extension String {
_asciiLowerCaseTable >>
UInt64(((value &- 1) & 0b0111_1111) >> 1)
let add = (isLower & 0x1) << 5
dest[i] = value &- UInt8(truncatingBitPattern: add)
dest.storeBytes(of: value &- UInt8(truncatingBitPattern: add),
toByteOffset: i, as: UInt8.self)
}
return String(_storage: buffer)
}