[WIP] Downgrade to Swift 5.0

.github/workflows/ci.yaml

@@ -4,18 +4,26 @@ on: [push, pull_request]
 
 jobs:
   unit-test:
+    strategy:
+      matrix:
+        # GitHub Actions replaces 5.0 with 5 so we have to be specific here
+        swift: [5.0.3, 5.1, 5.2]
     runs-on: ubuntu-latest
-    container: swift:5.2
+    container: swift:${{ matrix.swift }}
     steps:
       - name: Checkout
         uses: actions/checkout@v1
       - name: Resolve Swift dependencies
         run: swift package resolve
       - name: Build & Test
-        run: swift test -c release --enable-test-discovery
+        run: swift test
   compile-usecases:
+    strategy:
+      matrix:
+        # GitHub Actions replaces 5.0 with 5 so we have to be specific here
+        swift: [5.0.3, 5.1, 5.2]
     runs-on: ubuntu-latest
-    container: swift:5.2
+    container: swift:${{ matrix.swift }}
     steps:
       - name: Checkout
         uses: actions/checkout@v1

.swiftformat

@@ -1,8 +1,10 @@
 # file options
 
---swiftversion 5.2
+--swiftversion 5.0
 --exclude .build
 --exclude UseCases/.build
+--exclude Tests/LinuxMain.swift
+--exclude **/*Tests+XCTest.swift
 
 # format options
 

Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/slashmo/gsoc-swift-baggage-context.git",
         "state": {
           "branch": null,
-          "revision": "71ef1080972a1cac47ab80d995d6bdc370fb20f2",
-          "version": "0.2.0"
+          "revision": "744d984ac940535287cb036e44e6970c2a93f012",
+          "version": "0.3.0"
         }
       },
       {

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.2
+// swift-tools-version:5.0
 import PackageDescription
 
 let package = Package(
@@ -11,9 +11,8 @@ let package = Package(
     ],
     dependencies: [
         .package(
-            name: "swift-baggage-context",
             url: "https://github.com/slashmo/gsoc-swift-baggage-context.git",
-            from: "0.2.0"
+            from: "0.3.0"
         ),
         .package(url: "https://github.com/apple/swift-nio.git", from: "2.17.0")
     ],
@@ -24,7 +23,7 @@ let package = Package(
         .target(
             name: "Instrumentation",
             dependencies: [
-                .product(name: "Baggage", package: "swift-baggage-context"),
+                "Baggage",
             ]
         ),
         .testTarget(
@@ -37,23 +36,23 @@ let package = Package(
         .target(
             name: "TracingInstrumentation",
             dependencies: [
-                "Instrumentation"
+                "Instrumentation",
             ]
         ),
         .testTarget(
             name: "TracingInstrumentationTests",
             dependencies: [
                 "Instrumentation",
                 "TracingInstrumentation",
-                .product(name: "BaggageLogging", package: "swift-baggage-context"),
+                "BaggageLogging",
             ]
         ),
 
         .target(
             name: "NIOInstrumentation",
             dependencies: [
-                .product(name: "NIO", package: "swift-nio"),
-                .product(name: "NIOHTTP1", package: "swift-nio"),
+                "NIO",
+                "NIOHTTP1",
                 "Instrumentation",
             ]
         ),
@@ -73,22 +72,22 @@ let package = Package(
         .testTarget(
             name: "OpenTelemetryInstrumentationSupportTests",
             dependencies: [
-                "OpenTelemetryInstrumentationSupport"
+                "OpenTelemetryInstrumentationSupport",
             ]
         ),
 
         // ==== --------------------------------------------------------------------------------------------------------
         // MARK: Performance / Benchmarks
 
         .target(
-            name: "Benchmarks",
+            name: "TracingBenchmarks",
             dependencies: [
-                .product(name: "Baggage", package: "swift-baggage-context"),
-                "SwiftBenchmarkTools",
+                "Baggage",
+                "TracingBenchmarkTools",
             ]
         ),
         .target(
-            name: "SwiftBenchmarkTools",
+            name: "TracingBenchmarkTools",
             dependencies: []
         ),
     ]

Sources/Instrumentation/InstrumentationSystem.swift

@@ -65,7 +65,7 @@ public enum InstrumentationSystem {
     ///
     /// Defaults to a no-op `Instrument` if `boostrap` wasn't called before.
     public static var instrument: Instrument {
-        self.lock.withReaderLock { self._instrument }
+        return self.lock.withReaderLock { self._instrument }
     }
 
     /// Get an `Instrument` instance of the given type.
@@ -75,14 +75,14 @@ public enum InstrumentationSystem {
     /// - Parameter instrumentType: The type of `Instrument` you want to retrieve an instance for.
     /// - Returns: An `Instrument` instance of the given type or `nil` if no `Instrument` of that type has been bootstrapped.
     public static func instrument<I>(of instrumentType: I.Type) -> I? where I: Instrument {
-        self._findInstrument(where: { $0 is I }) as? I
+        return self._findInstrument(where: { $0 is I }) as? I
     }
 }
 
 extension InstrumentationSystem {
     /// :nodoc: INTERNAL API: Do Not Use
     public static func _findInstrument(where predicate: (Instrument) -> Bool) -> Instrument? {
-        self.lock.withReaderLock {
+        return self.lock.withReaderLock {
             if let multiplex = self._instrument as? MultiplexInstrument {
                 return multiplex.firstInstrument(where: predicate)
             } else if predicate(self._instrument) {

Sources/Instrumentation/MultiplexInstrument.swift

@@ -29,7 +29,7 @@ public struct MultiplexInstrument {
 
 extension MultiplexInstrument {
     func firstInstrument(where predicate: (Instrument) -> Bool) -> Instrument? {
-        self.instruments.first(where: predicate)
+        return self.instruments.first(where: predicate)
     }
 }
 

Sources/NIOInstrumentation/HTTPHeadersCarrier.swift

@@ -18,7 +18,7 @@ public struct HTTPHeadersExtractor: ExtractorProtocol {
     public init() {}
 
     public func extract(key: String, from headers: HTTPHeaders) -> String? {
-        headers.first(name: key)
+        return headers.first(name: key)
     }
 }
 

Sources/OpenTelemetryInstrumentationSupport/SpanAttribute+EndUser.swift

@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=5.2)
 import TracingInstrumentation
 
 extension SpanAttributes {
@@ -48,3 +49,4 @@ public struct EndUserAttributes: SpanAttributeNamespace {
         public var scope: SpanAttributeKey<String> { "enduser.scope" }
     }
 }
+#endif

Sources/OpenTelemetryInstrumentationSupport/SpanAttribute+HTTPSemantics.swift

@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=5.2)
 import TracingInstrumentation
 
 extension SpanAttributes {
@@ -98,3 +99,4 @@ public struct HTTPAttributes: SpanAttributeNamespace {
         public var serverClientIP: SpanAttributeKey<String> { "http.client_ip" }
     }
 }
+#endif

Sources/OpenTelemetryInstrumentationSupport/SpanAttribute+NetSemantics.swift

@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=5.2)
 import TracingInstrumentation
 
 extension SpanAttributes {
@@ -59,3 +60,4 @@ public struct NetAttributes: SpanAttributeNamespace {
         public var hostName: SpanAttributeKey<String> { "net.host.name" }
     }
 }
+#endif

Sources/OpenTelemetryInstrumentationSupport/SpanAttribute+PeerSemantics.swift

@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=5.2)
 import TracingInstrumentation
 
 extension SpanAttributes {
@@ -41,3 +42,4 @@ public struct PeerAttributes: SpanAttributeNamespace {
         public var service: SpanAttributeKey<String> { "peer.service" }
     }
 }
+#endif

Sources/SwiftBenchmarkTools/ArgParser.swift → Sources/TracingBenchmarkTools/ArgParser.swift

@@ -74,7 +74,7 @@ func checked<T>(
 class ArgumentParser<U> {
     private var result: U
     private var validOptions: [String] {
-        self.arguments.compactMap { $0.name }
+        return self.arguments.compactMap { $0.name }
     }
 
     private var arguments: [Argument] = []

Sources/SwiftBenchmarkTools/BenchmarkTools.swift → Sources/TracingBenchmarkTools/BenchmarkTools.swift

@@ -25,13 +25,13 @@ import Darwin
 
 extension BenchmarkCategory: CustomStringConvertible {
     public var description: String {
-        self.rawValue
+        return self.rawValue
     }
 }
 
 extension BenchmarkCategory: Comparable {
     public static func < (lhs: BenchmarkCategory, rhs: BenchmarkCategory) -> Bool {
-        lhs.rawValue < rhs.rawValue
+        return lhs.rawValue < rhs.rawValue
     }
 }
 
@@ -54,7 +54,7 @@ public struct BenchmarkPlatformSet: OptionSet {
     }
 
     public static var allPlatforms: BenchmarkPlatformSet {
-        [.darwin, .linux]
+        return [.darwin, .linux]
     }
 }
 
@@ -124,17 +124,17 @@ public struct BenchmarkInfo {
 
     /// Returns true if this benchmark should be run on the current platform.
     var shouldRun: Bool {
-        !self.unsupportedPlatforms.contains(.currentPlatform)
+        return !self.unsupportedPlatforms.contains(.currentPlatform)
     }
 }
 
 extension BenchmarkInfo: Comparable {
     public static func < (lhs: BenchmarkInfo, rhs: BenchmarkInfo) -> Bool {
-        lhs.name < rhs.name
+        return lhs.name < rhs.name
     }
 
     public static func == (lhs: BenchmarkInfo, rhs: BenchmarkInfo) -> Bool {
-        lhs.name == rhs.name
+        return lhs.name == rhs.name
     }
 }
 
@@ -175,7 +175,7 @@ public func SRand() {
 }
 
 public func Random() -> Int64 {
-    lfsrRandomGenerator.randInt()
+    return lfsrRandomGenerator.randInt()
 }
 
 @inlinable // FIXME(inline-always)
@@ -192,16 +192,16 @@ public func CheckResults(
     }
 }
 
-public func False() -> Bool { false }
+public func False() -> Bool { return false }
 
 /// This is a dummy protocol to test the speed of our protocol dispatch.
 public protocol SomeProtocol { func getValue() -> Int }
 struct MyStruct: SomeProtocol {
     init() {}
-    func getValue() -> Int { 1 }
+    func getValue() -> Int { return 1 }
 }
 
-public func someProtocolFactory() -> SomeProtocol { MyStruct() }
+public func someProtocolFactory() -> SomeProtocol { return MyStruct() }
 
 // Just consume the argument.
 // It's important that this function is in another module than the tests
@@ -212,19 +212,19 @@ public func blackHole<T>(_: T) {}
 // Return the passed argument without letting the optimizer know that.
 @inline(never)
 public func identity<T>(_ x: T) -> T {
-    x
+    return x
 }
 
 // Return the passed argument without letting the optimizer know that.
 // It's important that this function is in another module than the tests
 // which are using it.
 @inline(never)
-public func getInt(_ x: Int) -> Int { x }
+public func getInt(_ x: Int) -> Int { return x }
 
 // The same for String.
 @inline(never)
-public func getString(_ s: String) -> String { s }
+public func getString(_ s: String) -> String { return s }
 
 // The same for Substring.
 @inline(never)
-public func getSubstring(_ s: Substring) -> Substring { s }
+public func getSubstring(_ s: Substring) -> Substring { return s }