Add swiftpm manifest for locally built frameworks

Package.swift

@@ -0,0 +1,86 @@
+// swift-tools-version:5.9
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// NOTE: This package manifest is for frameworks built locally with CMake.
+// It defines dependencies and linker settings for Executorch components.
+//
+// To use prebuilt binaries instead, switch to one of the "swiftpm" branches,
+// which fetch the precompiled `.xcframeworks`.
+//
+// For details on building frameworks locally or using prebuilt binaries,
+// see the documentation:
+// https://pytorch.org/executorch/main/using-executorch-ios.html
+
+import PackageDescription
+
+let debug = "_debug"
+let deliverables = [
+  "backend_coreml": [
+    "frameworks": [
+      "Accelerate",
+      "CoreML",
+    ],
+    "libraries": [
+      "sqlite3",
+    ],
+  ],
+  "backend_mps": [
+    "frameworks": [
+      "Metal",
+      "MetalPerformanceShaders",
+      "MetalPerformanceShadersGraph",
+    ],
+  ],
+  "backend_xnnpack": [:],
+  "executorch": [:],
+  "kernels_custom": [:],
+  "kernels_optimized": [:],
+  "kernels_portable": [:],
+  "kernels_quantized": [:],
+].reduce(into: [String: [String: Any]]()) {
+  $0[$1.key] = $1.value
+  $0[$1.key + debug] = $1.value
+}.reduce(into: [String: [String: Any]]()) {
+  var newValue = $1.value
+  if $1.key.hasSuffix(debug) {
+    $1.value.forEach { key, value in
+      if key.hasSuffix(debug) {
+        newValue[String(key.dropLast(debug.count))] = value
+      }
+    }
+  }
+  $0[$1.key] = newValue.filter { key, _ in !key.hasSuffix(debug) }
+}
+
+let package = Package(
+  name: "executorch",
+  platforms: [
+    .iOS(.v17),
+    .macOS(.v10_15),
+  ],
+  products: deliverables.keys.map { key in
+    .library(name: key, targets: ["\(key)_dependencies"])
+  }.sorted { $0.name < $1.name },
+  targets: deliverables.flatMap { key, value -> [Target] in
+    [
+      .binaryTarget(
+        name: key,
+        path: "cmake-out/\(key).xcframework"
+      ),
+      .target(
+        name: "\(key)_dependencies",
+        dependencies: [.target(name: key)],
+        path: ".Package.swift/\(key)",
+        linkerSettings:
+          (value["frameworks"] as? [String] ?? []).map { .linkedFramework($0) } +
+          (value["libraries"] as? [String] ?? []).map { .linkedLibrary($0) }
+      ),
+    ]
+  }
+)