[AltJIT] Adds AltJIT CLI tool to enable JIT on devices running iOS 17+

Commands:

altjit enable [app/pid] --udid [udid]
* Enables JIT for given app/process

altjit mount --udid [udid]
* Mounts personalized developer disk

Shared/Errors/ALTLocalizedError.swift

@@ -7,7 +7,10 @@
 //
 
 import Foundation
+
+#if !ALTJIT
 import AltSign
+#endif
 
 public let ALTLocalizedTitleErrorKey = "ALTLocalizedTitle"
 public let ALTLocalizedDescriptionKey = "ALTLocalizedDescription"

Shared/Errors/JITError.swift

@@ -0,0 +1,52 @@
+//
+//  JITError.swift
+//  AltJIT
+//
+//  Created by Riley Testut on 9/3/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+extension JITError
+{
+    enum Code: Int, ALTErrorCode
+    {
+        typealias Error = JITError
+        
+        case processNotRunning
+    }
+    
+    static func processNotRunning(_ process: AppProcess, file: StaticString = #file, line: Int = #line) -> JITError {
+        JITError(code: .processNotRunning, process: process, sourceFile: file, sourceLine: UInt(line))
+    }
+}
+
+struct JITError: ALTLocalizedError
+{
+    let code: Code
+    
+    var errorTitle: String?
+    var errorFailure: String?
+    
+    @UserInfoValue var process: AppProcess?
+    
+    var sourceFile: StaticString?
+    var sourceLine: UInt?
+    
+    var errorFailureReason: String {
+        switch self.code
+        {
+        case .processNotRunning:
+            let targetName = self.process?.description ?? NSLocalizedString("The target app", comment: "")
+            return String(format: NSLocalizedString("%@ is not running.", comment: ""), targetName)
+        }
+    }
+    
+    var recoverySuggestion: String? {
+        switch self.code
+        {
+        case .processNotRunning: return NSLocalizedString("Make sure the app is running in the foreground on your device then try again.", comment: "")
+        }
+    }
+}

Shared/Errors/ProcessError.swift

@@ -0,0 +1,88 @@
+//
+//  ProcessError.swift
+//  AltPackage
+//
+//  Created by Riley Testut on 9/1/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+extension ProcessError
+{
+    enum Code: Int, ALTErrorCode
+    {
+        typealias Error = ProcessError
+        
+        case failed
+        case timedOut
+        case unexpectedOutput
+        case terminated
+    }
+    
+    static func failed(executableURL: URL, exitCode: Int32, output: String?, file: StaticString = #file, line: Int = #line) -> ProcessError {
+        ProcessError(code: .failed, executableURL: executableURL, exitCode: exitCode, output: output, sourceFile: file, sourceLine: UInt(line))
+    }
+            
+    static func timedOut(executableURL: URL, exitCode: Int32? = nil, output: String? = nil, file: StaticString = #file, line: Int = #line) -> ProcessError {
+        ProcessError(code: .timedOut, executableURL: executableURL, exitCode: exitCode, output: output, sourceFile: file, sourceLine: UInt(line))
+    }
+    
+    static func unexpectedOutput(executableURL: URL, output: String, exitCode: Int32? = nil, file: StaticString = #file, line: Int = #line) -> ProcessError {
+        ProcessError(code: .unexpectedOutput, executableURL: executableURL, exitCode: exitCode, output: output, sourceFile: file, sourceLine: UInt(line))
+    }
+    
+    static func terminated(executableURL: URL, exitCode: Int32, output: String, file: StaticString = #file, line: Int = #line) -> ProcessError {
+        ProcessError(code: .terminated, executableURL: executableURL, exitCode: exitCode, output: output, sourceFile: file, sourceLine: UInt(line))
+    }
+}
+
+struct ProcessError: ALTLocalizedError
+{
+    let code: Code
+    
+    var errorTitle: String?
+    var errorFailure: String?
+    
+    @UserInfoValue var executableURL: URL?
+    @UserInfoValue var exitCode: Int32?
+    @UserInfoValue var output: String?
+    
+    var sourceFile: StaticString?
+    var sourceLine: UInt?
+    
+    var errorFailureReason: String {
+        switch self.code
+        {
+        case .failed:
+            guard let exitCode else { return String(format: NSLocalizedString("%@ failed.", comment: ""), self.processName) }
+            
+            let baseMessage = String(format: NSLocalizedString("%@ failed with code %@.", comment: ""), self.processName, NSNumber(value: exitCode))
+            guard let lastLine = self.lastOutputLine else { return baseMessage }
+            
+            let failureReason = baseMessage + " " + lastLine
+            return failureReason
+            
+        case .timedOut: return String(format: NSLocalizedString("%@ timed out.", comment: ""), self.processName)
+        case .terminated: return String(format: NSLocalizedString("%@ unexpectedly quit.", comment: ""), self.processName)
+        case .unexpectedOutput:
+            let baseMessage = String(format: NSLocalizedString("%@ returned unexpected output.", comment: ""), self.processName)
+            guard let lastLine = self.lastOutputLine else { return baseMessage }
+            
+            let failureReason = baseMessage + " " + lastLine
+            return failureReason
+        }
+    }
+    
+    private var processName: String {
+        guard let executableName = self.executableURL?.lastPathComponent else { return NSLocalizedString("The process", comment: "") }
+        return String(format: NSLocalizedString("The process '%@'", comment: ""), executableName)
+    }
+    
+    private var lastOutputLine: String? {
+        guard let output else { return nil }
+        
+        let lastLine = output.components(separatedBy: .newlines).last(where: { !$0.isEmpty })
+        return lastLine
+    }
+}