fix(Messenger - Remove Meta AI): Improve patch logic (#5153)

Author: drobotk

extensions/messenger/src/main/java/app/revanced/extension/messenger/metaai/RemoveMetaAIPatch.java

@@ -1,15 +1,23 @@
 package app.revanced.extension.messenger.metaai;
 
+import java.util.*;
+
+import app.revanced.extension.shared.Logger;
+
 @SuppressWarnings("unused")
 public class RemoveMetaAIPatch {
+    private static final Set<Long> loggedIDs = Collections.synchronizedSet(new HashSet<>());
+
     public static boolean overrideBooleanFlag(long id, boolean value) {
-        // This catches all flag IDs related to Meta AI.
-        // The IDs change slightly with every update,
-        // so to work around this, IDs from different versions were compared
-        // to find what they have in common, which turned out to be those first bits.
-        // TODO: Find the specific flags that we care about and patch the code they control instead.
-        if ((id & 0x7FFFFFC000000000L) == 0x810A8000000000L) {
-            return false;
+        try {
+            if (Long.toString(id).startsWith("REPLACED_BY_PATCH")) {
+                if (loggedIDs.add(id))
+                    Logger.printInfo(() -> "Overriding " + id + " from " + value + " to false");
+
+                return false;
+            }
+        } catch (Exception ex) {
+            Logger.printException(() -> "overrideBooleanFlag failure", ex);
         }
 
         return value;

patches/src/main/kotlin/app/revanced/patches/messenger/metaai/Fingerprints.kt

@@ -11,3 +11,15 @@ internal val getMobileConfigBoolFingerprint = fingerprint {
         classDef.interfaces.contains("Lcom/facebook/mobileconfig/factory/MobileConfigUnsafeContext;")
     }
 }
+
+internal val metaAIKillSwitchCheckFingerprint = fingerprint {
+    strings("SearchAiagentImplementationsKillSwitch")
+    opcodes(Opcode.CONST_WIDE)
+}
+
+internal val extensionMethodFingerprint = fingerprint {
+    strings("REPLACED_BY_PATCH")
+    custom { method, classDef ->
+        method.name == EXTENSION_METHOD_NAME && classDef.type == EXTENSION_CLASS_DESCRIPTOR
+    }
+}

patches/src/main/kotlin/app/revanced/patches/messenger/metaai/RemoveMetaAIPatch.kt

@@ -2,11 +2,14 @@ package app.revanced.patches.messenger.metaai
 
 import app.revanced.patcher.extensions.InstructionExtensions.addInstructions
 import app.revanced.patcher.extensions.InstructionExtensions.getInstruction
+import app.revanced.patcher.extensions.InstructionExtensions.replaceInstruction
 import app.revanced.patcher.patch.bytecodePatch
 import app.revanced.patches.messenger.misc.extension.sharedExtensionPatch
 import com.android.tools.smali.dexlib2.iface.instruction.OneRegisterInstruction
+import com.android.tools.smali.dexlib2.iface.instruction.WideLiteralInstruction
 
-private const val EXTENSION_CLASS_DESCRIPTOR = "Lapp/revanced/extension/messenger/metaai/RemoveMetaAIPatch;"
+internal const val EXTENSION_CLASS_DESCRIPTOR = "Lapp/revanced/extension/messenger/metaai/RemoveMetaAIPatch;"
+internal const val EXTENSION_METHOD_NAME = "overrideBooleanFlag"
 
 @Suppress("unused")
 val removeMetaAIPatch = bytecodePatch(
@@ -25,10 +28,25 @@ val removeMetaAIPatch = bytecodePatch(
             addInstructions(
                 returnIndex,
                 """
-                    invoke-static { p1, p2, v$returnRegister }, $EXTENSION_CLASS_DESCRIPTOR->overrideBooleanFlag(JZ)Z
+                    invoke-static { p1, p2, v$returnRegister }, $EXTENSION_CLASS_DESCRIPTOR->$EXTENSION_METHOD_NAME(JZ)Z
                     move-result v$returnRegister
                 """
             )
         }
+
+        // Extract the common starting digits of Meta AI flag IDs from a flag found in code.
+        val relevantDigits = with(metaAIKillSwitchCheckFingerprint) {
+            method.getInstruction<WideLiteralInstruction>(patternMatch!!.startIndex).wideLiteral
+        }.toString().substring(0, 7)
+
+        // Replace placeholder in the extension method.
+        with(extensionMethodFingerprint) {
+            method.replaceInstruction(
+                stringMatches!!.first().index,
+                """
+                    const-string v1, "$relevantDigits"
+                """
+            )
+        }
     }
 }

patches/src/main/kotlin/app/revanced/patches/messenger/misc/extension/ExtensionPatch.kt

@@ -2,4 +2,4 @@ package app.revanced.patches.messenger.misc.extension
 
 import app.revanced.patches.shared.misc.extension.sharedExtensionPatch
 
-val sharedExtensionPatch = sharedExtensionPatch("messenger", mainActivityOnCreateHook)
+val sharedExtensionPatch = sharedExtensionPatch("messenger", messengerApplicationOnCreateHook)

patches/src/main/kotlin/app/revanced/patches/messenger/misc/extension/Hooks.kt

@@ -2,6 +2,8 @@ package app.revanced.patches.messenger.misc.extension
 
 import app.revanced.patches.shared.misc.extension.extensionHook
 
-internal val mainActivityOnCreateHook = extensionHook {
-    strings("MainActivity_onCreate_begin")
+internal val messengerApplicationOnCreateHook = extensionHook {
+    custom { method, classDef ->
+        method.name == "onCreate" && classDef.endsWith("/MessengerApplication;")
+    }
 }