mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
4cd1e812b7
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:)
173 lines
4.5 KiB
Swift
173 lines
4.5 KiB
Swift
// RUN: %empty-directory(%t)
|
||
// RUN: %target-build-swift %s -o %t/a.out_Debug -Onone
|
||
// RUN: %target-build-swift %s -o %t/a.out_Release -O
|
||
//
|
||
// RUN: %target-codesign %t/a.out_Debug
|
||
// RUN: %target-codesign %t/a.out_Release
|
||
// RUN: %target-run %t/a.out_Debug
|
||
// RUN: %target-run %t/a.out_Release
|
||
// REQUIRES: executable_test
|
||
|
||
import StdlibUnittest
|
||
|
||
let testSuiteSuffix = _isDebugAssertConfiguration() ? "_debug" : "_release"
|
||
|
||
var StringTraps = TestSuite("StringTraps" + testSuiteSuffix)
|
||
|
||
StringTraps.test("startIndex/predecessor")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.startIndex
|
||
i = s.index(after: i)
|
||
i = s.index(before: i)
|
||
expectCrashLater()
|
||
i = s.index(before: i)
|
||
}
|
||
|
||
StringTraps.test("endIndex/successor")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.startIndex
|
||
i = s.index(after: i)
|
||
i = s.index(after: i)
|
||
i = s.index(after: i)
|
||
expectCrashLater()
|
||
i = s.index(after: i)
|
||
}
|
||
|
||
StringTraps.test("subscript(_:)/endIndex")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.startIndex
|
||
i = s.index(after: i)
|
||
i = s.index(after: i)
|
||
i = s.index(after: i)
|
||
expectCrashLater()
|
||
_ = s[i]
|
||
}
|
||
|
||
StringTraps.test("UTF8ViewSubscript/endIndexSuccessor")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.utf8.startIndex
|
||
i = s.utf8.index(after: i)
|
||
i = s.utf8.index(after: i)
|
||
i = s.utf8.index(after: i)
|
||
expectCrashLater()
|
||
i = s.utf8.index(after: i)
|
||
_ = s.utf8[i]
|
||
}
|
||
|
||
StringTraps.test("UTF8ViewSubscript/endIndex")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.utf8.startIndex
|
||
i = s.utf8.index(after: i)
|
||
i = s.utf8.index(after: i)
|
||
i = s.utf8.index(after: i)
|
||
expectCrashLater()
|
||
_ = s.utf8[i]
|
||
}
|
||
|
||
StringTraps.test("UTF16ViewSubscript/DecrementedStartIndex")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s = "abc"
|
||
var i = s.utf16.startIndex
|
||
expectCrashLater()
|
||
i = s.utf16.index(before: i)
|
||
_ = s.utf16[i]
|
||
}
|
||
|
||
StringTraps.test("UTF16ViewSubscript/endIndex")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
var s = "abc"
|
||
var i = s.utf16.startIndex
|
||
i = s.utf16.index(after: i)
|
||
i = s.utf16.index(after: i)
|
||
i = s.utf16.index(after: i)
|
||
expectCrashLater()
|
||
_ = s.utf16[i]
|
||
}
|
||
|
||
StringTraps.test("UTF16ViewIndex/offsetLimited")
|
||
.code {
|
||
let sa = "foo"
|
||
let u16a = sa.utf16
|
||
let s16 = sa + "🤦🏻♀️"
|
||
let u16 = s16.utf16
|
||
|
||
let iaBegin = u16a.index(sa.startIndex, offsetBy: 99, limitedBy: sa.endIndex)
|
||
expectNil(iaBegin)
|
||
let iaEnd = u16a.index(sa.endIndex, offsetBy: 99, limitedBy: sa.endIndex)
|
||
expectNil(iaEnd)
|
||
let i16Begin = u16.index(u16.startIndex, offsetBy: 99, limitedBy: u16.endIndex)
|
||
expectNil(i16Begin)
|
||
let i16End = u16.index(u16.startIndex, offsetBy: 99, limitedBy: u16.endIndex)
|
||
expectNil(i16End)
|
||
}
|
||
|
||
StringTraps.test("UTF16ViewIndex/offsetCrash")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s16 = "foo🤦🏻♀️"
|
||
let u16 = s16.utf16
|
||
expectCrashLater()
|
||
let i = u16.index(u16.startIndex, offsetBy: 99)
|
||
_ = s16.utf16[i]
|
||
}
|
||
|
||
StringTraps.test("UTF8ViewIndex/offsetLimited")
|
||
.code {
|
||
let sa = "foo"
|
||
let u8a = sa.utf8
|
||
let s8 = sa + "🤦🏻♀️"
|
||
let u8 = s8.utf8
|
||
|
||
let iaBegin = u8a.index(sa.startIndex, offsetBy: 99, limitedBy: sa.endIndex)
|
||
expectNil(iaBegin)
|
||
let iaEnd = u8a.index(sa.endIndex, offsetBy: 99, limitedBy: sa.endIndex)
|
||
expectNil(iaEnd)
|
||
let i8Begin = u8.index(u8.startIndex, offsetBy: 99, limitedBy: u8.endIndex)
|
||
expectNil(i8Begin)
|
||
let i8End = u8.index(u8.startIndex, offsetBy: 99, limitedBy: u8.endIndex)
|
||
expectNil(i8End)
|
||
}
|
||
|
||
StringTraps.test("UTF8ViewIndex/offsetCrash")
|
||
.skip(.custom(
|
||
{ _isFastAssertConfiguration() },
|
||
reason: "this trap is not guaranteed to happen in -Ounchecked"))
|
||
.code {
|
||
let s8 = "foo🤦🏻♀️"
|
||
let u8 = s8.utf8
|
||
expectCrashLater()
|
||
let i = u8.index(u8.startIndex, offsetBy: 99)
|
||
_ = s8.utf8[i]
|
||
}
|
||
|
||
runAllTests()
|
||
|