Enable building prebuilts on linux hosts without docker. (#8269)

Made discovery of the Linux distro reusable for the build-prebuilts
script. Changed it to use arch and os conditions instead of the host
toolchain.

Added support for Ubuntu noble, Fedora and Debian.

Removed the deletion of the stage directory so we can share it across
docker invocations for each distro. Fixed the Modules directory name
which wasn't working on case sensitive file systems.

Author: dschaefer2

Sources/Workspace/Workspace+Prebuilts.swift

@@ -86,17 +86,20 @@ extension Workspace {
             case macos_x86_64
             case windows_aarch64
             case windows_x86_64
-            // noble is currently missing
+            case ubuntu_noble_aarch64
+            case ubuntu_noble_x86_64
             case ubuntu_jammy_aarch64
             case ubuntu_jammy_x86_64
             case ubuntu_focal_aarch64
             case ubuntu_focal_x86_64
-            // bookworm is currently missing
-            // fedora39 is currently missing
+            case fedora_39_aarch64
+            case fedora_39_x86_64
             case amazonlinux2_aarch64
             case amazonlinux2_x86_64
             case rhel_ubi9_aarch64
             case rhel_ubi9_x86_64
+            case debian_12_aarch64
+            case debian_12_x86_64
 
             public enum Arch: String {
                 case x86_64
@@ -108,35 +111,6 @@ extension Workspace {
                 case windows
                 case linux
             }
-
-            public var arch: Arch {
-                switch self {
-                case .macos_aarch64, .windows_aarch64,
-                    .ubuntu_jammy_aarch64, .ubuntu_focal_aarch64,
-                    .amazonlinux2_aarch64,
-                    .rhel_ubi9_aarch64:
-                    return .aarch64
-                case .macos_x86_64, .windows_x86_64,
-                    .ubuntu_jammy_x86_64, .ubuntu_focal_x86_64,
-                    .amazonlinux2_x86_64,
-                    .rhel_ubi9_x86_64:
-                    return .x86_64
-                }
-            }
-
-            public var os: OS {
-                switch self {
-                case .macos_aarch64, .macos_x86_64:
-                    return .macos
-                case .windows_aarch64, .windows_x86_64:
-                    return .windows
-                case .ubuntu_jammy_aarch64, .ubuntu_jammy_x86_64,
-                    .ubuntu_focal_aarch64, .ubuntu_focal_x86_64,
-                    .amazonlinux2_aarch64, .amazonlinux2_x86_64,
-                    .rhel_ubi9_aarch64, .rhel_ubi9_x86_64:
-                    return .linux
-                }
-            }
         }
     }
 
@@ -145,15 +119,18 @@ extension Workspace {
         let httpClient: HTTPClient?
         let archiver: Archiver?
         let useCache: Bool?
+        let hostPlatform: PrebuiltsManifest.Platform?
 
         public init(
             httpClient: HTTPClient? = .none,
             archiver: Archiver? = .none,
-            useCache: Bool? = .none
+            useCache: Bool? = .none,
+            hostPlatform: PrebuiltsManifest.Platform? = nil
         ) {
             self.httpClient = httpClient
             self.archiver = archiver
             self.useCache = useCache
+            self.hostPlatform = hostPlatform
         }
     }
 
@@ -170,9 +147,11 @@ extension Workspace {
         private let delegate: Delegate?
         private let hashAlgorithm: HashAlgorithm = SHA256()
         private let prebuiltsDownloadURL: URL
+        let hostPlatform: PrebuiltsManifest.Platform
 
         init(
             fileSystem: FileSystem,
+            hostPlatform: PrebuiltsManifest.Platform,
             authorizationProvider: AuthorizationProvider?,
             scratchPath: AbsolutePath,
             cachePath: AbsolutePath?,
@@ -182,6 +161,7 @@ extension Workspace {
             prebuiltsDownloadURL: String?
         ) {
             self.fileSystem = fileSystem
+            self.hostPlatform = hostPlatform
             self.authorizationProvider = authorizationProvider
             self.httpClient = customHTTPClient ?? HTTPClient()
             self.archiver = customArchiver ?? ZipArchiver(fileSystem: fileSystem)
@@ -515,7 +495,7 @@ extension Workspace {
         addedOrUpdatedPackages: [PackageReference],
         observabilityScope: ObservabilityScope
     ) async throws {
-        guard let prebuiltsManager = self.prebuiltsManager else {
+        guard let prebuiltsManager else {
             // Disabled
             return
         }
@@ -536,14 +516,10 @@ extension Workspace {
                 continue
             }
 
-            let hostPlatform = hostPrebuiltsPlatform
+            let hostPlatform = prebuiltsManager.hostPlatform
 
             for library in prebuiltManifest.libraries {
-                for artifact in library.artifacts {
-                    guard artifact.platform == hostPlatform else {
-                        continue
-                    }
-
+                for artifact in library.artifacts where artifact.platform == hostPlatform {
                     if let path = try await prebuiltsManager
                         .downloadPrebuilt(
                             package: prebuilt,
@@ -577,100 +553,167 @@ extension Workspace {
 
         try self.state.save()
     }
+}
+
+extension Workspace.PrebuiltsManifest.Platform {
+    public var arch: Arch {
+        switch self {
+        case .macos_aarch64, .windows_aarch64,
+            .ubuntu_noble_aarch64, .ubuntu_jammy_aarch64, .ubuntu_focal_aarch64,
+            .fedora_39_aarch64,
+            .amazonlinux2_aarch64,
+            .rhel_ubi9_aarch64,
+            .debian_12_aarch64:
+            return .aarch64
+        case .macos_x86_64, .windows_x86_64,
+            .ubuntu_noble_x86_64, .ubuntu_jammy_x86_64, .ubuntu_focal_x86_64,
+            .fedora_39_x86_64,
+            .amazonlinux2_x86_64,
+            .rhel_ubi9_x86_64,
+            .debian_12_x86_64:
+            return .x86_64
+        }
+    }
+
+    public var os: OS {
+        switch self {
+        case .macos_aarch64, .macos_x86_64:
+            return .macos
+        case .windows_aarch64, .windows_x86_64:
+            return .windows
+        case .ubuntu_noble_aarch64, .ubuntu_noble_x86_64,
+            .ubuntu_jammy_aarch64, .ubuntu_jammy_x86_64,
+            .ubuntu_focal_aarch64, .ubuntu_focal_x86_64,
+            .fedora_39_aarch64, .fedora_39_x86_64,
+            .amazonlinux2_aarch64, .amazonlinux2_x86_64,
+            .rhel_ubi9_aarch64, .rhel_ubi9_x86_64,
+            .debian_12_aarch64, .debian_12_x86_64:
+            return .linux
+        }
+    }
 
-    var hostPrebuiltsPlatform: PrebuiltsManifest.Platform? {
-        if self.hostToolchain.targetTriple.isDarwin() {
-            switch self.hostToolchain.targetTriple.arch {
-            case .aarch64:
-                return .macos_aarch64
-            case .x86_64:
-                return .macos_x86_64
+    /// Determine host platform based on compilation target
+    public static var hostPlatform: Self? {
+        let arch: Arch?
+#if arch(arm64)
+        arch = .aarch64
+#elseif arch(x86_64)
+        arch = .x86_64
+#endif
+        guard let arch else {
+            return nil
+        }
+
+#if os(macOS)
+        switch arch {
+        case .aarch64:
+            return .macos_aarch64
+        case .x86_64:
+            return .macos_x86_64
+        }
+#elseif os(Windows)
+        switch arch {
+        case .aarch64:
+            return .windows_aarch64
+        case .x86_64:
+            return .windows_x86_64
+        }
+#elseif os(Linux)
+        // Load up the os-release file into a dictionary
+        guard let osData = try? String(contentsOfFile: "/etc/os-release", encoding: .utf8)
+        else {
+            return nil
+        }
+        let osLines = osData.split(separator: "\n")
+        let osDict = osLines.reduce(into: [Substring: String]()) {
+            (dict, line) in
+            let parts = line.split(separator: "=", maxSplits: 2)
+            dict[parts[0]] = parts[1...].joined(separator: "=").trimmingCharacters(in: ["\""])
+        }
+
+        switch osDict["ID"] {
+        case "ubuntu":
+            switch osDict["VERSION_CODENAME"] {
+            case "noble":
+                switch arch {
+                case .aarch64:
+                    return .ubuntu_noble_aarch64
+                case .x86_64:
+                    return .ubuntu_noble_x86_64
+                }
+            case "jammy":
+                switch arch {
+                case .aarch64:
+                    return .ubuntu_jammy_aarch64
+                case .x86_64:
+                    return .ubuntu_jammy_x86_64
+                }
+            case "focal":
+                switch arch {
+                case .aarch64:
+                    return .ubuntu_focal_aarch64
+                case .x86_64:
+                    return .ubuntu_focal_x86_64
+                }
             default:
                 return nil
             }
-        } else if self.hostToolchain.targetTriple.isWindows() {
-            switch self.hostToolchain.targetTriple.arch {
-            case .aarch64:
-                return .windows_aarch64
-            case .x86_64:
-                return .windows_x86_64
+        case "fedora":
+            switch osDict["VERSION_ID"] {
+            case "39", "41":
+                switch arch {
+                case .aarch64:
+                    return .fedora_39_aarch64
+                case .x86_64:
+                    return .fedora_39_x86_64
+                }
             default:
                 return nil
             }
-        } else if self.hostToolchain.targetTriple.isLinux() {
-            // Load up the os-release file into a dictionary
-            guard let osData = try? String(contentsOfFile: "/etc/os-release", encoding: .utf8)
-            else {
+        case "amzn":
+            switch osDict["VERSION_ID"] {
+            case "2":
+                switch arch {
+                case .aarch64:
+                    return .amazonlinux2_aarch64
+                case .x86_64:
+                    return .amazonlinux2_x86_64
+                }
+            default:
                 return nil
             }
-            let osLines = osData.split(separator: "\n")
-            let osDict = osLines.reduce(into: [Substring: String]()) {
-                (dict, line) in
-                let parts = line.split(separator: "=", maxSplits: 2)
-                dict[parts[0]] = parts[1...].joined(separator: "=").trimmingCharacters(in: ["\""])
+        case "rhel":
+            guard let version = osDict["VERSION_ID"] else {
+                return nil
             }
-
-            switch osDict["ID"] {
-            case "ubuntu":
-                switch osDict["VERSION_CODENAME"] {
-                case "jammy":
-                    switch self.hostToolchain.targetTriple.arch {
-                    case .aarch64:
-                        return .ubuntu_jammy_aarch64
-                    case .x86_64:
-                        return .ubuntu_jammy_x86_64
-                    default:
-                        return nil
-                    }
-                case "focal":
-                    switch self.hostToolchain.targetTriple.arch {
-                    case .aarch64:
-                        return .ubuntu_focal_aarch64
-                    case .x86_64:
-                        return .ubuntu_focal_x86_64
-                    default:
-                        return nil
-                    }
-                default:
-                    return nil
+            switch version.split(separator: ".")[0] {
+            case "9":
+                switch arch {
+                case .aarch64:
+                    return .rhel_ubi9_aarch64
+                case .x86_64:
+                    return .rhel_ubi9_x86_64
                 }
-            case "amzn":
-                switch osDict["VERSION_ID"] {
-                case "2":
-                    switch self.hostToolchain.targetTriple.arch {
-                    case .aarch64:
-                        return .amazonlinux2_aarch64
-                    case .x86_64:
-                        return .amazonlinux2_x86_64
-                    default:
-                        return nil
-                    }
-                default:
-                    return nil
-                }
-            case "rhel":
-                guard let version = osDict["VERSION_ID"] else {
-                    return nil
-                }
-                switch version.split(separator: ".")[0] {
-                case "9":
-                    switch self.hostToolchain.targetTriple.arch {
-                    case .aarch64:
-                        return .rhel_ubi9_aarch64
-                    case .x86_64:
-                        return .rhel_ubi9_x86_64
-                    default:
-                        return nil
-                    }
-                default:
-                    return nil
+            default:
+                return nil
+            }
+        case "debian":
+            switch osDict["VERSION_ID"] {
+            case "12":
+                switch arch {
+                case .aarch64:
+                    return .debian_12_aarch64
+                case .x86_64:
+                    return .debian_12_x86_64
                 }
             default:
                 return nil
             }
-        } else {
+        default:
             return nil
         }
+#else
+        return nil
+#endif
     }
-
 }