Remove platform requirement from Package.swift

Package.swift

@@ -3,12 +3,6 @@ import PackageDescription
 
 let package = Package(
     name: "swift-distributed-tracing",
-    platforms: [
-        .macOS(.v10_15),
-        .iOS(.v13),
-        .tvOS(.v13),
-        .watchOS(.v6),
-    ],
     products: [
         .library(name: "Instrumentation", targets: ["Instrumentation"]),
         .library(name: "Tracing", targets: ["Tracing"]),

Sources/Tracing/InstrumentationSystem+Tracing.swift

@@ -14,6 +14,7 @@
 
 @_exported import Instrumentation
 
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 extension InstrumentationSystem {
     #if swift(>=5.7.0)
     /// Returns the ``Tracer`` bootstrapped as part of the `InstrumentationSystem`.

Sources/Tracing/NoOpTracer.swift

@@ -91,6 +91,7 @@ public struct NoOpTracer: LegacyTracer {
 }
 
 #if swift(>=5.7.0)
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 extension NoOpTracer: Tracer {
     public func startSpan<Instant: TracerInstant>(
         _ operationName: String,

Sources/Tracing/Tracer.swift

@@ -276,6 +276,7 @@ public func withSpan<T>(
 ///   - operation: The operation that this span should be measuring
 /// - Returns: the value returned by `operation`
 /// - Throws: the error the `operation` has thrown (if any)
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 public func withSpan<T>(
     _ operationName: String,
     context: @autoclosure () -> ServiceContext = .current ?? .topLevel,
@@ -418,6 +419,7 @@ public func withSpan<T>(
 ///   - operation: The operation that this span should be measuring
 /// - Returns: the value returned by `operation`
 /// - Throws: the error the `operation` has thrown (if any)
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 public func withSpan<T>(
     _ operationName: String,
     context: @autoclosure () -> ServiceContext = .current ?? .topLevel,

Sources/Tracing/TracerProtocol+Legacy.swift

@@ -388,6 +388,7 @@ extension LegacyTracer {
 #if swift(>=5.7.0)
 // Provide compatibility shims of the `...AnySpan` APIs to the 5.7 requiring `Tracer`.
 
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 extension Tracer {
     /// Start a new span returning an existential ``Span`` reference.
     ///

Sources/Tracing/TracerProtocol.swift

@@ -113,6 +113,7 @@ extension Tracer {
 // ==== ----------------------------------------------------------------------------------------------------------------
 // MARK: Starting spans: `withSpan`
 
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 extension Tracer {
     /// Start a new ``Span`` and automatically end when the `operation` completes,
     /// including recording the `error` in case the operation throws.

Sources/_TracingBenchmarks/SpanAttributesDSLBenchmark.swift

@@ -15,121 +15,141 @@
 import _TracingBenchmarkTools
 import Tracing
 
-public let SpanAttributesDSLBenchmarks: [BenchmarkInfo] = [
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.000_bench_empty",
-        runFunction: { _ in try! bench_empty(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.001_bench_makeSpan",
-        runFunction: { _ in try! bench_makeSpan(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.002_bench_startSpan_end",
-        runFunction: { _ in try! bench_makeSpan(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.00_bench_set_String_raw",
-        runFunction: { _ in try! bench_set_String_raw(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.01_bench_set_String_dsl",
-        runFunction: { _ in try! bench_set_String_dsl(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.02_bench_set_Int_raw",
-        runFunction: { _ in try! bench_set_String_raw(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-    BenchmarkInfo(
-        name: "SpanAttributesDSLBenchmarks.03_bench_set_Int_dsl",
-        runFunction: { _ in try! bench_set_String_dsl(times: 100) },
-        tags: [],
-        setUpFunction: { setUp() },
-        tearDownFunction: tearDown
-    ),
-]
-
-private var span: (any Tracing.Span)!
-
-private func setUp() {
-    span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
-}
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *) // for TaskLocal ServiceContext
+enum DSLBenchmarks {
+    public static let SpanAttributesDSLBenchmarks: [BenchmarkInfo] = [
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.000_bench_empty",
+            runFunction: { _ in try! bench_empty(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.001_bench_makeSpan",
+            runFunction: { _ in try! bench_makeSpan(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.002_bench_startSpan_end",
+            runFunction: { _ in try! bench_makeSpan(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.00_bench_set_String_raw",
+            runFunction: { _ in try! bench_set_String_raw(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.01_bench_set_String_dsl",
+            runFunction: { _ in try! bench_set_String_dsl(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.02_bench_set_Int_raw",
+            runFunction: { _ in try! bench_set_String_raw(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+        BenchmarkInfo(
+            name: "SpanAttributesDSLBenchmarks.03_bench_set_Int_dsl",
+            runFunction: { _ in try! bench_set_String_dsl(times: 100) },
+            tags: [],
+            setUpFunction: { setUp() },
+            tearDownFunction: tearDown
+        ),
+    ]
+
+    fileprivate static var span: (any Tracing.Span)!
+
+    fileprivate static func setUp() {
+        self.span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
+    }
 
-private func tearDown() {
-    span = nil
-}
+    fileprivate static func tearDown() {
+        self.span = nil
+    }
 
-// ==== ----------------------------------------------------------------------------------------------------------------
-// MARK: make span
+    // ==== ----------------------------------------------------------------------------------------------------------------
+    // MARK: make span
 
-func bench_empty(times: Int) throws {}
+    static func bench_empty(times: Int) throws {}
 
-func bench_makeSpan(times: Int) throws {
-    for _ in 0 ..< times {
-        let span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
-        _ = span
+    static func bench_makeSpan(times: Int) throws {
+        for _ in 0 ..< times {
+            let span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
+            _ = span
+        }
     }
-}
 
-func bench_startSpan_end(times: Int) throws {
-    for _ in 0 ..< times {
-        let span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
-        span.end()
+    static func bench_startSpan_end(times: Int) throws {
+        for _ in 0 ..< times {
+            let span = InstrumentationSystem.legacyTracer.startAnySpan("something", context: .topLevel)
+            span.end()
+        }
     }
-}
 
-// ==== ----------------------------------------------------------------------------------------------------------------
-// MARK: set String
+    // ==== ----------------------------------------------------------------------------------------------------------------
+    // MARK: set String
 
-func bench_set_String_raw(times: Int) throws {
-    for _ in 0 ..< times {
-        span.attributes["http.method"] = "POST"
+    static func bench_set_String_raw(times: Int) throws {
+        for _ in 0 ..< times {
+            self.span.attributes["http.method"] = "POST"
+        }
     }
-}
 
-func bench_set_String_dsl(times: Int) throws {
-    for _ in 0 ..< times {
-        span.attributes.http.method = "POST"
+    static func bench_set_String_dsl(times: Int) throws {
+        for _ in 0 ..< times {
+            self.span.attributes.http.method = "POST"
+        }
     }
-}
 
-// ==== ----------------------------------------------------------------------------------------------------------------
-// MARK: set Int
+    // ==== ----------------------------------------------------------------------------------------------------------------
+    // MARK: set Int
 
-func bench_set_Int_raw(times: Int) throws {
-    for _ in 0 ..< times {
-        span.attributes["http.status_code"] = 200
+    static func bench_set_Int_raw(times: Int) throws {
+        for _ in 0 ..< times {
+            self.span.attributes["http.status_code"] = 200
+        }
     }
-}
 
-func bench_set_Int_dsl(times: Int) throws {
-    for _ in 0 ..< times {
-        span.attributes.http.statusCode = 200
+    static func bench_set_Int_dsl(times: Int) throws {
+        for _ in 0 ..< times {
+            self.span.attributes.http.statusCode = 200
+        }
+    }
+
+    @dynamicMemberLookup
+    struct HTTPAttributes: SpanAttributeNamespace {
+        var attributes: SpanAttributes
+
+        init(attributes: SpanAttributes) {
+            self.attributes = attributes
+        }
+
+        struct NestedSpanAttributes: NestedSpanAttributesProtocol {
+            init() {}
+
+            var method: Key<String> { "http.method" }
+            var statusCode: Key<Int> { "http.status_code" }
+        }
     }
 }
 
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *) // for TaskLocal ServiceContext
 extension SpanAttributes {
-    var http: HTTPAttributes {
+    var http: DSLBenchmarks.HTTPAttributes {
         get {
             .init(attributes: self)
         }
@@ -138,19 +158,3 @@ extension SpanAttributes {
         }
     }
 }
-
-@dynamicMemberLookup
-struct HTTPAttributes: SpanAttributeNamespace {
-    var attributes: SpanAttributes
-
-    init(attributes: SpanAttributes) {
-        self.attributes = attributes
-    }
-
-    struct NestedSpanAttributes: NestedSpanAttributesProtocol {
-        init() {}
-
-        var method: Key<String> { "http.method" }
-        var statusCode: Key<Int> { "http.status_code" }
-    }
-}

Sources/_TracingBenchmarks/main.swift

@@ -37,6 +37,7 @@ private func registerBenchmark(_ name: String, _ function: @escaping (Int) -> Vo
     registerBenchmark(BenchmarkInfo(name: name, runFunction: function, tags: tags))
 }
 
-registerBenchmark(SpanAttributesDSLBenchmarks)
-
-main()
+if #available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *) { // for TaskLocal ServiceContext
+    registerBenchmark(DSLBenchmarks.SpanAttributesDSLBenchmarks)
+    main()
+}