Flag queues whose driver filters need Rosetta or are missing

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Sources/CupsKit/DriverFilters.swift

@@ -0,0 +1,157 @@
+import Darwin
+import Foundation
+
+/// One filter program a PPD names in `*cupsFilter` / `*cupsFilter2`, and whether it can run natively.
+public struct DriverFilter: Hashable {
+    public enum Status: Hashable {
+        /// Has an arm64 slice (arm64, arm64e or newer subtypes).
+        case native(architectures: [String])
+        /// Intel only: needs Rosetta on Apple silicon.
+        case intelOnly(architectures: [String])
+        /// A script (`#!`); runs wherever its interpreter does.
+        case script(interpreter: String)
+        /// `-`: no program, cupsd passes the data through.
+        case passthrough
+        case missing
+        /// Exists but isn't a Mach-O binary or script this check understands.
+        case unrecognized
+    }
+
+    public let keyword: String
+    /// The line's value, e.g. `application/vnd.cups-postscript 0 /Library/Printers/…/pstopsRV2`.
+    public let line: String
+    public let program: String
+    /// Resolved absolute path; nil for `-`.
+    public let path: String?
+    public let status: Status
+
+    public var name: String { (program as NSString).lastPathComponent }
+}
+
+public struct DriverFilterReport: Hashable {
+    public let filters: [DriverFilter]
+
+    public var intelOnly: [DriverFilter] { filters.filter { if case .intelOnly = $0.status { return true } else { return false } } }
+    public var missing: [DriverFilter] { filters.filter { $0.status == .missing } }
+    public var needsRosetta: Bool { !intelOnly.isEmpty }
+    public var hasMissingFilter: Bool { !missing.isEmpty }
+    public var isFlagged: Bool { needsRosetta || hasMissingFilter }
+
+    /// "Driver filter missing" (worse, shown first) or "Driver needs Rosetta"; nil when fine.
+    public var headline: String? {
+        if hasMissingFilter { return "Driver filter missing" }
+        if needsRosetta { return "Driver needs Rosetta" }
+        return nil
+    }
+
+    /// e.g. "pstopsRV2, commandfilterRV1 are Intel-only (x86_64); /Library/…/foo not found".
+    public var detail: String? {
+        var parts: [String] = []
+        if !missing.isEmpty {
+            parts.append(missing.compactMap(\.path).joined(separator: ", ") + " not found")
+        }
+        if !intelOnly.isEmpty {
+            let names = intelOnly.map(\.name)
+            let archs = Set(intelOnly.flatMap { if case .intelOnly(let a) = $0.status { return a } else { return [] } }).sorted()
+            parts.append("\(names.joined(separator: ", ")) \(names.count == 1 ? "is" : "are") Intel-only (\(archs.joined(separator: ", ")))")
+        }
+        return parts.isEmpty ? nil : parts.joined(separator: "; ")
+    }
+
+    /// One line for CLI output: "Driver needs Rosetta — pstopsRV2 is Intel-only (x86_64)".
+    public var warning: String? {
+        guard let headline, let detail else { return nil }
+        return "\(headline) — \(detail)"
+    }
+}
+
+public enum DriverFilterCheck {
+    /// Where cupsd looks for filters named without a path.
+    public static let filterDirectory = "/usr/libexec/cups/filter"
+
+    public static func check(_ ppd: PPD, filterDirectory: String = filterDirectory) -> DriverFilterReport {
+        var seen = Set<String>()
+        var filters: [DriverFilter] = []
+        for (keyword, value) in ppd.filterLines {
+            // cupsFilter: "type cost program"; cupsFilter2: "source destination cost [maxsize(n)] program".
+            var fields = value.split(separator: " ", omittingEmptySubsequences: true).map(String.init)
+            let skip = keyword == "cupsFilter2" ? 3 : 2
+            guard fields.count > skip else { continue }
+            fields.removeFirst(skip)
+            if let first = fields.first, first.hasPrefix("maxsize("), first.hasSuffix(")") { fields.removeFirst() }
+            guard !fields.isEmpty else { continue }
+            let program = fields.joined(separator: " ")
+            let path: String? = program == "-" ? nil
+                : program.hasPrefix("/") ? program : (filterDirectory as NSString).appendingPathComponent(program)
+            guard seen.insert(path ?? "-\(keyword)").inserted else { continue }
+            let status: DriverFilter.Status = path.map(Self.status(atPath:)) ?? .passthrough
+            filters.append(DriverFilter(keyword: keyword, line: value, program: program, path: path, status: status))
+        }
+        return DriverFilterReport(filters: filters)
+    }
+
+    /// Reads the file's header: Mach-O (thin or universal) or `#!` script.
+    public static func status(atPath path: String) -> DriverFilter.Status {
+        guard FileManager.default.fileExists(atPath: path) else { return .missing }
+        guard let handle = FileHandle(forReadingAtPath: path) else { return .unrecognized }
+        defer { try? handle.close() }
+        let header = [UInt8](handle.readData(ofLength: 4096))
+        return status(header: header)
+    }
+
+    static func status(header b: [UInt8]) -> DriverFilter.Status {
+        guard b.count >= 8 else { return .unrecognized }
+        if b[0] == UInt8(ascii: "#"), b[1] == UInt8(ascii: "!") {
+            let line = b.prefix { $0 != UInt8(ascii: "\n") }.dropFirst(2)
+            return .script(interpreter: String(decoding: line, as: UTF8.self).trimmingCharacters(in: .whitespaces))
+        }
+        func be32(_ i: Int) -> UInt32 { UInt32(b[i]) << 24 | UInt32(b[i + 1]) << 16 | UInt32(b[i + 2]) << 8 | UInt32(b[i + 3]) }
+        func le32(_ i: Int) -> UInt32 { UInt32(b[i + 3]) << 24 | UInt32(b[i + 2]) << 16 | UInt32(b[i + 1]) << 8 | UInt32(b[i]) }
+
+        var cpuTypes: [(type: UInt32, subtype: UInt32)] = []
+        switch be32(0) {
+        case 0xCAFEBABE, 0xCAFEBABF:   // universal (fat32 / fat64)
+            let count = Int(be32(4))
+            let entrySize = be32(0) == 0xCAFEBABF ? 32 : 20
+            guard count > 0, count < 32 else { return .unrecognized }   // Java class files share the magic
+            for i in 0 ..< count {
+                let offset = 8 + i * entrySize
+                guard offset + 8 <= b.count else { break }
+                cpuTypes.append((be32(offset), be32(offset + 4) & 0x00FF_FFFF))
+            }
+        default:
+            switch le32(0) {
+            case 0xFEEDFACF, 0xFEEDFACE:   // thin Mach-O, little-endian
+                cpuTypes.append((le32(4), le32(8) & 0x00FF_FFFF))
+            default:
+                return .unrecognized
+            }
+        }
+        let names = cpuTypes.map { architectureName(type: $0.type, subtype: $0.subtype) }
+        if cpuTypes.contains(where: { $0.type == 0x0100_000C }) { return .native(architectures: names) }
+        if cpuTypes.contains(where: { $0.type == 0x0100_0007 || $0.type == 7 }) { return .intelOnly(architectures: names) }
+        return .unrecognized
+    }
+
+    static func architectureName(type: UInt32, subtype: UInt32) -> String {
+        switch type {
+        case 0x0100_0007: return "x86_64"
+        case 7: return "i386"
+        case 0x0100_000C: return subtype == 2 ? "arm64e" : "arm64"
+        case 0x0200_000C: return "arm64_32"
+        case 12: return "arm"
+        default: return "cpu\(type)"
+        }
+    }
+
+    /// True on Apple silicon (also when this process itself runs under Rosetta).
+    public static var hostIsAppleSilicon: Bool {
+        var value: Int32 = 0
+        var size = MemoryLayout<Int32>.size
+        return sysctlbyname("hw.optional.arm64", &value, &size, nil, 0) == 0 && value == 1
+    }
+
+    public static var rosettaInstalled: Bool {
+        FileManager.default.fileExists(atPath: "/Library/Apple/usr/libexec/oah/libRosettaRuntime")
+    }
+}