feat: Add String feature flag logging

ReVanced · Nov 12, 2024 · f5a3048 · f5a3048
1 parent 9b98f5f
commit f5a3048
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Showing 5 changed files with 62 additions and 2 deletions.
diff --git a/...ons/shared/src/main/java/app/revanced/extension/youtube/patches/EnableDebuggingPatch.java b/...ons/shared/src/main/java/app/revanced/extension/youtube/patches/EnableDebuggingPatch.java
@@ -53,4 +53,18 @@ public static long isLongFeatureFlagEnabled(long value, long flag, long defaultV
 
         return value;
     }
+
+    /**
+     * Injection point.
+     */
+    public static String isStringFeatureFlagEnabled(String value, long flag, String defaultValue) {
+        if (BaseSettings.DEBUG.get() && !defaultValue.equals(value)) {
+            if (featureFlags.putIfAbsent(flag, true) == null) {
+                Logger.printDebug(() -> " string feature is enabled: " + flag
+                        + " value: " + value + " default: " + defaultValue);
+            }
+        }
+
+        return value;
+    }
 }
diff --git a/patches/api/patches.api b/patches/api/patches.api
@@ -1444,10 +1444,12 @@ public final class app/revanced/util/BytecodeUtilsKt {
 	public static final fun indexOfFirstInstructionOrThrow (Lcom/android/tools/smali/dexlib2/iface/Method;Lcom/android/tools/smali/dexlib2/Opcode;)I
 	public static synthetic fun indexOfFirstInstructionOrThrow$default (Lcom/android/tools/smali/dexlib2/iface/Method;ILcom/android/tools/smali/dexlib2/Opcode;ILjava/lang/Object;)I
 	public static synthetic fun indexOfFirstInstructionOrThrow$default (Lcom/android/tools/smali/dexlib2/iface/Method;ILkotlin/jvm/functions/Function1;ILjava/lang/Object;)I
+	public static final fun indexOfFirstInstructionReversed (Lcom/android/tools/smali/dexlib2/iface/Method;Lcom/android/tools/smali/dexlib2/Opcode;)I
 	public static final fun indexOfFirstInstructionReversed (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lcom/android/tools/smali/dexlib2/Opcode;)I
 	public static final fun indexOfFirstInstructionReversed (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lkotlin/jvm/functions/Function1;)I
 	public static synthetic fun indexOfFirstInstructionReversed$default (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lcom/android/tools/smali/dexlib2/Opcode;ILjava/lang/Object;)I
 	public static synthetic fun indexOfFirstInstructionReversed$default (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)I
+	public static final fun indexOfFirstInstructionReversedOrThrow (Lcom/android/tools/smali/dexlib2/iface/Method;Lcom/android/tools/smali/dexlib2/Opcode;)I
 	public static final fun indexOfFirstInstructionReversedOrThrow (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lcom/android/tools/smali/dexlib2/Opcode;)I
 	public static final fun indexOfFirstInstructionReversedOrThrow (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lkotlin/jvm/functions/Function1;)I
 	public static synthetic fun indexOfFirstInstructionReversedOrThrow$default (Lcom/android/tools/smali/dexlib2/iface/Method;Ljava/lang/Integer;Lcom/android/tools/smali/dexlib2/Opcode;ILjava/lang/Object;)I

diff --git a/patches/src/main/kotlin/app/revanced/patches/youtube/misc/debugging/EnableDebuggingPatch.kt b/patches/src/main/kotlin/app/revanced/patches/youtube/misc/debugging/EnableDebuggingPatch.kt
@@ -11,6 +11,7 @@ import app.revanced.patches.youtube.misc.extension.sharedExtensionPatch
 import app.revanced.patches.youtube.misc.settings.PreferenceScreen
 import app.revanced.patches.youtube.misc.settings.settingsPatch
 import app.revanced.util.indexOfFirstInstructionOrThrow
+import app.revanced.util.indexOfFirstInstructionReversedOrThrow
 import com.android.tools.smali.dexlib2.Opcode
 
 private const val EXTENSION_CLASS_DESCRIPTOR =
@@ -105,7 +106,23 @@ val enableDebuggingPatch = bytecodePatch(
             )
         }
 
-        // There exists other experimental accessor methods for String, byte[], and wrappers for obfuscated classes,
-        // but currently none of those are hooked.
+        experimentalStringFeatureFlagFingerprint.match(
+            experimentalFeatureFlagParentFingerprint.originalClassDef
+        ).method.apply {
+            val insertIndex = indexOfFirstInstructionReversedOrThrow(Opcode.MOVE_RESULT_OBJECT)
+
+            addInstructions(
+                insertIndex,
+                """
+                    move-result-object v0
+                    invoke-static { v0, p1, p2, p3 }, $EXTENSION_CLASS_DESCRIPTOR->isStringFeatureFlagEnabled(Ljava/lang/String;JLjava/lang/String;)Ljava/lang/String;
+                    move-result-object v0
+                    return-object v0
+                """
+            )
+        }
+
+        // There exists other experimental accessor methods for byte[]
+        // and wrappers for obfuscated classes, but currently none of those are hooked.
     }
 }
diff --git a/patches/src/main/kotlin/app/revanced/patches/youtube/misc/debugging/Fingerprints.kt b/patches/src/main/kotlin/app/revanced/patches/youtube/misc/debugging/Fingerprints.kt
@@ -28,3 +28,9 @@ internal val experimentalLongFeatureFlagFingerprint = fingerprint {
     parameters("J", "J")
 }
 
+internal val experimentalStringFeatureFlagFingerprint = fingerprint {
+    accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
+    returns("Ljava/lang/String;")
+    parameters("J", "Ljava/lang/String;")
+}
+
diff --git a/patches/src/main/kotlin/app/revanced/util/BytecodeUtils.kt b/patches/src/main/kotlin/app/revanced/util/BytecodeUtils.kt
@@ -309,6 +309,17 @@ fun Method.indexOfFirstInstructionReversed(startIndex: Int? = null, filter: Inst
     return instructions.indexOfLast(filter)
 }
 
+/**
+ * Get the index of matching instruction,
+ * starting from the end of the method and searching down.
+ *
+ * @return -1 if the instruction is not found.
+ */
+fun Method.indexOfFirstInstructionReversed(targetOpcode: Opcode): Int =
+    indexOfFirstInstructionReversed {
+        opcode == targetOpcode
+    }
+
 /**
  * Get the index of matching instruction,
  * starting from and [startIndex] and searching down.
@@ -322,6 +333,16 @@ fun Method.indexOfFirstInstructionReversedOrThrow(startIndex: Int? = null, targe
         opcode == targetOpcode
     }
 
+/**
+ * Get the index of matching instruction,
+ * starting from the end of the method and searching down.
+ *
+ * @return -1 if the instruction is not found.
+ */
+fun Method.indexOfFirstInstructionReversedOrThrow(targetOpcode: Opcode): Int =
+    indexOfFirstInstructionReversedOrThrow {
+        opcode == targetOpcode
+    }
 /**
  * Get the index of matching instruction,
  * starting from and [startIndex] and searching down.