From 4020039065afdce265b5140e1d4989da87b42280 Mon Sep 17 00:00:00 2001
From: Marc Prud'hommeaux <mwp1@cornell.edu>
Date: Sat, 17 May 2025 16:39:38 -0400
Subject: [PATCH 1/2] Make SwiftSDKMetadataV4.sdkRootPath optional

---
 Sources/PackageModel/SwiftSDKs/SwiftSDK.swift | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift b/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift
index cdcdfd781f4..767460ed862 100644
--- a/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift
+++ b/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift
@@ -350,7 +350,9 @@ public struct SwiftSDK: Equatable {
         fileprivate init(_ properties: SwiftSDKMetadataV4.TripleProperties, swiftSDKDirectory: Basics.AbsolutePath? = nil) throws {
             if let swiftSDKDirectory {
                 self.init(
-                    sdkRootPath: try AbsolutePath(validating: properties.sdkRootPath, relativeTo: swiftSDKDirectory),
+                    sdkRootPath: try properties.sdkRootPath.map {
+                        try AbsolutePath(validating: $0, relativeTo: swiftSDKDirectory)
+                    },
                     swiftResourcesPath: try properties.swiftResourcesPath.map {
                         try AbsolutePath(validating: $0, relativeTo: swiftSDKDirectory)
                     },
@@ -369,7 +371,9 @@ public struct SwiftSDK: Equatable {
                 )
             } else {
                 self.init(
-                    sdkRootPath: try AbsolutePath(validating: properties.sdkRootPath),
+                    sdkRootPath: try properties.sdkRootPath.map {
+                        try AbsolutePath(validating: $0)
+                    },
                     swiftResourcesPath: try properties.swiftResourcesPath.map {
                         try AbsolutePath(validating: $0)
                     },
@@ -1167,7 +1171,7 @@ struct SerializedDestinationV3: Decodable {
 struct SwiftSDKMetadataV4: Decodable {
     struct TripleProperties: Codable {
         /// Path relative to `swift-sdk.json` containing SDK root.
-        var sdkRootPath: String
+        var sdkRootPath: String?
 
         /// Path relative to `swift-sdk.json` containing Swift resources for dynamic linking.
         var swiftResourcesPath: String?

From afdaa3f1b76fb3f3f1c6b2bd6a1342147e6f39d4 Mon Sep 17 00:00:00 2001
From: Marc Prud'hommeaux <mwp1@cornell.edu>
Date: Sun, 18 May 2025 16:07:14 -0400
Subject: [PATCH 2/2] Add test case for androidWithoutSDKRootPathSwiftSDKv4

---
 Tests/PackageModelTests/SwiftSDKTests.swift | 42 +++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/Tests/PackageModelTests/SwiftSDKTests.swift b/Tests/PackageModelTests/SwiftSDKTests.swift
index 7f7a5dd9650..d3c6b2f0643 100644
--- a/Tests/PackageModelTests/SwiftSDKTests.swift
+++ b/Tests/PackageModelTests/SwiftSDKTests.swift
@@ -25,6 +25,7 @@ private let hostTriple = try! Triple("arm64-apple-darwin22.1.0")
 private let olderHostTriple = try! Triple("arm64-apple-darwin20.1.0")
 private let linuxGNUTargetTriple = try! Triple("x86_64-unknown-linux-gnu")
 private let linuxMuslTargetTriple = try! Triple("x86_64-unknown-linux-musl")
+private let androidTargetTriple = try! Triple("aarch64-unknown-linux-android28")
 private let wasiTargetTriple = try! Triple("wasm32-unknown-wasi")
 private let extraFlags = BuildFlags(
     cCompilerFlags: ["-fintegrated-as"],
@@ -186,6 +187,20 @@ private let toolsetRootSwiftSDKv4 = (
     """# as SerializedJSON
 )
 
+private let androidWithoutSDKRootPathSwiftSDKv4 = (
+    path: bundleRootPath.appending(component: "androidWithoutSDKRootPathSwiftSDKv4.json"),
+    json: #"""
+    {
+        "targetTriples": {
+            "\#(androidTargetTriple.tripleString)": {
+                "toolsetPaths": ["/tools/otherToolsNoRoot.json"]
+            }
+        },
+        "schemaVersion": "4.0"
+    }
+    """# as SerializedJSON
+)
+
 private let missingToolsetSwiftSDKv4 = (
     path: bundleRootPath.appending(component: "missingToolsetSwiftSDKv4.json"),
     json: #"""
@@ -351,6 +366,23 @@ private let parsedToolsetRootDestination = SwiftSDK(
     )
 )
 
+private let parsedToolsetNoSDKRootPathDestination = SwiftSDK(
+    targetTriple: androidTargetTriple,
+    toolset: .init(
+        knownTools: [
+            .librarian: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.librarian]!)")),
+            .linker: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.linker]!)")),
+            .debugger: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.debugger]!)")),
+        ],
+        rootPaths: []
+    ),
+    pathsConfiguration: .init(
+        sdkRootPath: nil,
+        toolsetPaths: ["/tools/otherToolsNoRoot.json"]
+            .map { try! AbsolutePath(validating: $0) }
+    )
+)
+
 private let testFiles: [(path: AbsolutePath, json: SerializedJSON)] = [
     destinationV1,
     destinationV2,
@@ -365,6 +397,7 @@ private let testFiles: [(path: AbsolutePath, json: SerializedJSON)] = [
     invalidVersionSwiftSDKv4,
     invalidToolsetSwiftSDKv4,
     wasiWithoutToolsetsSwiftSDKv4,
+    androidWithoutSDKRootPathSwiftSDKv4,
     otherToolsNoRoot,
     someToolsWithRoot,
     invalidToolset,
@@ -488,6 +521,15 @@ final class SwiftSDKTests: XCTestCase {
 
         XCTAssertEqual(toolsetRootSwiftSDKv4Decoded, [parsedToolsetRootDestination])
 
+        let androidWithoutSDKRootPathSwiftSDKv4Decoded = try SwiftSDK.decode(
+            fromFile: androidWithoutSDKRootPathSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
+            fileSystem: fs,
+            observabilityScope: observability
+        )
+
+        XCTAssertEqual(androidWithoutSDKRootPathSwiftSDKv4Decoded, [parsedToolsetNoSDKRootPathDestination])
+
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: missingToolsetSwiftSDKv4.path,
             hostToolchainBinDir: toolchainBinAbsolutePath,