From 2cd0ec9ee76c49f81a7076ed72fa3812fec59995 Mon Sep 17 00:00:00 2001
From: Aliaksandr Babrykovich <aliaksandr.babrykovich@callstack.com>
Date: Wed, 15 Apr 2026 15:34:17 +0200
Subject: [PATCH] fix: replace objc_getClassList with
 objc_copyClassNamesForImage to avoid class realization

objc_getClassList forces the ObjC runtime to realize every registered class,
which crashes on iOS 16 when the host app contains @Observable classes guarded
by @available(iOS 17, *). objc_copyClassNamesForImage reads class name strings
from Mach-O metadata without realizing any class, avoiding the crash.

Fixes #220
---
 HCaptcha/Classes/HCaptchaDebugInfo.swift | 39 +++++++++++-------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/HCaptcha/Classes/HCaptchaDebugInfo.swift b/HCaptcha/Classes/HCaptchaDebugInfo.swift
index fc0c0031..9d9f3bf8 100644
--- a/HCaptcha/Classes/HCaptchaDebugInfo.swift
+++ b/HCaptcha/Classes/HCaptchaDebugInfo.swift
@@ -8,6 +8,7 @@
 import Foundation
 import CommonCrypto
 import UIKit
+import MachO
 
 private extension String {
     func jsSanitize() -> String {
@@ -51,31 +52,25 @@ class HCaptchaDebugInfo {
         CC_MD5_Init(sysCtx)
         CC_MD5_Init(appCtx)
 
-        let loadedCount = Int(min(objc_getClassList(nil, 0), 1024))
-        if loadedCount > 0 {
-            let classes = UnsafeMutablePointer<AnyClass?>.allocate(capacity: loadedCount)
-            defer { classes.deallocate() }
+        let imageCount = _dyld_image_count()
+        for imageIdx in 0..<imageCount {
+            guard let imageNamePtr = _dyld_get_image_name(imageIdx) else { continue }
+            let imagePath = String(cString: imageNamePtr)
 
-            _ = objc_getClassList(AutoreleasingUnsafeMutablePointer(classes), Int32(loadedCount))
-
-            for idx in 0..<loadedCount {
-                if let `class` = classes[idx] {
-                    var info = Dl_info()
-                    if dladdr(unsafeBitCast(`class`, to: UnsafeRawPointer.self), &info) != 0,
-                            let imagePathPtr = info.dli_fname {
-                        let imagePath = String(cString: imagePathPtr)
+            var md5Ctx = depsCtx
+            if imagePath.isSystemFramework {
+                md5Ctx = sysCtx
+            } else if let execPath = Bundle.main.executablePath, imagePath.hasPrefix(execPath) {
+                md5Ctx = appCtx
+            }
 
-                        var md5Ctx = depsCtx
-                        if imagePath.isSystemFramework {
-                            md5Ctx = sysCtx
-                        } else if let execPath = Bundle.main.executablePath, imagePath.hasPrefix(execPath) {
-                            md5Ctx = appCtx
-                        }
+            var classCount: UInt32 = 0
+            guard let classNames = objc_copyClassNamesForImage(imageNamePtr, &classCount) else { continue }
+            defer { free(classNames) }
 
-                        let className = NSStringFromClass(`class`)
-                        CC_MD5_Update(md5Ctx, className, CC_LONG(className.count))
-                    }
-                }
+            for classIdx in 0..<Int(classCount) {
+                let className = String(cString: classNames[classIdx])
+                CC_MD5_Update(md5Ctx, className, CC_LONG(className.count))
             }
         }