Fix literal pattern availability (#720)

- Updates `_literalPattern` availability to 5.11
- Fixes an issue with testConcurrentAccess, where the
test crashes if declared with unrestricted availability.
- Fixes a release mode testing issue, where the call to disable 
optimizations during testing was in an assert call, so it was 
elided in release builds, even though the code that expected
optimizations to be disabled was still used. This created spurious
failures during release mode testing, which appears to have
recently been enabled in CI.

Author: natecook1000

Package.swift

@@ -15,7 +15,15 @@ let availabilityDefinition = PackageDescription.SwiftSetting.unsafeFlags([
     "-Xfrontend",
     "-define-availability",
     "-Xfrontend",
-    "SwiftStdlib 5.9:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999",
+    "SwiftStdlib 5.9:macOS 14.0, iOS 17.0, watchOS 10.0, tvOS 17.0",
+    "-Xfrontend",
+    "-define-availability",
+    "-Xfrontend",
+    "SwiftStdlib 5.10:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999",
+    "-Xfrontend",
+    "-define-availability",
+    "-Xfrontend",
+    "SwiftStdlib 5.11:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999",
 ])
 
 /// Swift settings for building a private stdlib-like module that is to be used
@@ -89,7 +97,7 @@ let package = Package(
             name: "RegexTests",
             dependencies: ["_StringProcessing", "TestSupport"],
             swiftSettings: [
-                .unsafeFlags(["-Xfrontend", "-disable-availability-checking"]),
+                availabilityDefinition
             ]),
         .testTarget(
             name: "RegexBuilderTests",

Sources/_StringProcessing/LiteralPrinter.swift

@@ -11,7 +11,7 @@
 
 @_implementationOnly import _RegexParser
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.7, *)
 extension Regex {
   /// The literal pattern for this regex.
   ///
@@ -33,6 +33,7 @@ extension Regex {
   /// the `CustomConsumingRegexComponent` protocol, this property is `nil`.
   ///
   /// The value of this property may change between different releases of Swift.
+  @available(SwiftStdlib 5.11, *)
   public var _literalPattern: String? {
     var gen = LiteralPrinter(options: MatchingOptions())
     gen.outputNode(self.program.tree.root)

Tests/RegexTests/LiteralPrinterTests.swift

@@ -14,6 +14,7 @@ import XCTest
 import _StringProcessing
 import RegexBuilder
 
+@available(SwiftStdlib 5.11, *)
 extension RegexTests {
   func testPrintableRegex() throws {
     let regexString = #"([a-fGH1-9[^\D]]+)?b*cd(e.+)\2\w\S+?"#
@@ -55,7 +56,7 @@ extension RegexTests {
 // MARK: - PrintableRegex
 
 // Demonstration of a guaranteed Codable/Sendable regex type.
-@available(macOS 9999, *)
+@available(SwiftStdlib 5.11, *)
 struct PrintableRegex: RegexComponent, @unchecked Sendable {
   var pattern: String
   var regex: Regex<AnyRegexOutput>
@@ -76,7 +77,7 @@ struct PrintableRegex: RegexComponent, @unchecked Sendable {
   }
 }
 
-@available(macOS 9999, *)
+@available(SwiftStdlib 5.11, *)
 extension PrintableRegex: Codable {
   init(from decoder: Decoder) throws {
     let container = try decoder.singleValueContainer()
@@ -90,7 +91,7 @@ extension PrintableRegex: Codable {
   }
 }
 
-@available(macOS 9999, *)
+@available(SwiftStdlib 5.11, *)
 extension PrintableRegex: CustomStringConvertible {
   var description: String {
     pattern

Tests/RegexTests/MatchTests.swift

@@ -23,6 +23,7 @@ struct MatchError: Error {
 
 // This just piggy-backs on the existing match testing to validate that
 // literal patterns round trip correctly.
+@available(SwiftStdlib 5.11, *)
 func _roundTripLiteral(
   _ regexStr: String,
   syntax: SyntaxOptions
@@ -87,7 +88,7 @@ func _firstMatch(
     }
   }
 
-  do {
+  if #available(SwiftStdlib 5.11, *) {
     let roundTripRegex = try? _roundTripLiteral(regexStr, syntax: syntax)
     let roundTripResult = try? roundTripRegex?
       .matchingSemantics(semanticLevel)
@@ -137,7 +138,7 @@ func _firstMatch(
   }
 
   if validateOptimizations {
-    assert(regex._forceAction(.addOptions(.disableOptimizations)))
+    precondition(regex._forceAction(.addOptions(.disableOptimizations)))
     let unoptResult = try regex.firstMatch(in: input)
     if result != nil && unoptResult == nil {
       throw MatchError("match not found for unoptimized \(regexStr) in \(input)")

Tests/RegexTests/ParseTests.swift

@@ -119,7 +119,8 @@ func parseTest(
   }
   serializedCaptures.deallocate()
 
-  if !unsupported && expectedErrors.isEmpty,
+  if #available(SwiftStdlib 5.11, *),
+     !unsupported && expectedErrors.isEmpty,
      let pattern = Regex<AnyRegexOutput>(ast: ast)._literalPattern
   {
     let reparsedAST = parseWithRecovery(pattern, syntax)