chore(script): add example deobf from toString script (#1996)

jadx-plugins/jadx-script/examples/scripts/deobf_from_tostring.jadx.kts

@@ -0,0 +1,89 @@
+/*
+ Rename class and fields using strings from toString() method
+*/
+
+import jadx.core.deobf.NameMapper
+import jadx.core.dex.attributes.AFlag
+import jadx.core.dex.attributes.nodes.RenameReasonAttr
+import jadx.core.dex.info.FieldInfo
+import jadx.core.dex.instructions.ConstStringNode
+import jadx.core.dex.instructions.IndexInsnNode
+import jadx.core.dex.instructions.InsnType
+import jadx.core.dex.instructions.args.InsnWrapArg
+import jadx.core.dex.nodes.InsnNode
+import jadx.core.dex.nodes.MethodNode
+import jadx.plugins.script.runtime.data.ScriptOrderedDecompilePass
+
+val jadx = getJadxInstance()
+
+// StringBuilder chain replaced by STR_CONCAT instruction in SimplifyVisitor
+// Search for return with STR_CONCAT and process args
+jadx.addPass(object : ScriptOrderedDecompilePass(
+	jadx,
+	"DeobfFromToString",
+	runAfter = listOf("SimplifyVisitor"),
+) {
+	override fun visit(mth: MethodNode) {
+		if (mth.methodInfo.shortId == "toString()Ljava/lang/String;") {
+			val returnBlock = mth.exitBlock.predecessors.firstOrNull { it.contains(AFlag.RETURN) }
+			val lastInsn = returnBlock?.instructions?.lastOrNull()
+			if (lastInsn != null && lastInsn.type == InsnType.RETURN) {
+				val arg = lastInsn.getArg(0)
+				if (arg.isInsnWrap) {
+					val wrapInsn = (arg as InsnWrapArg).wrapInsn
+					if (wrapInsn.type == InsnType.STR_CONCAT) {
+						log.info { "Renaming using 'toString' in class: ${mth.parentClass}" }
+						processArgs(mth, wrapInsn)
+					}
+				}
+			}
+		}
+	}
+
+	val clsSepRgx = Regex("[ ({:]")
+
+	private fun processArgs(mth: MethodNode, wrapInsn: InsnNode): Boolean {
+		try {
+			var fldName: String? = null
+			for ((i, arg) in wrapInsn.arguments.withIndex()) {
+				val insn = arg.unwrap() ?: return false
+				if (i % 2 == 0) {
+					if (insn !is ConstStringNode) {
+						return false
+					}
+					var str = insn.string
+					if (i == 0) {
+						// class and first field name
+						val parts = str.split(clsSepRgx)
+						val clsName = parts[0]
+						if (NameMapper.isValidIdentifier(clsName)) {
+							mth.parentClass.run {
+								log.info { "rename class '$name' to '$clsName'" }
+								rename(clsName)
+								RenameReasonAttr.forNode(this).append("from toString()")
+							}
+						}
+						str = parts[1]
+					}
+					fldName = str.trim('\'', '=', ',', ' ', ':')
+				} else {
+					if (insn.type != InsnType.IGET) {
+						return false
+					}
+					val iget = insn as IndexInsnNode
+					val fldInfo = iget.index as FieldInfo
+					val fld = mth.parentClass.searchField(fldInfo)
+					if (fld != null && NameMapper.isValidIdentifier(fldName)) {
+						log.info { "rename field '${fld.name}' to '$fldName'" }
+						fld.rename(fldName)
+						RenameReasonAttr.forNode(fld).append("from toString()")
+					}
+				}
+			}
+			return true
+		} catch (e: Exception) {
+			log.error(e) { "Args process failed" }
+			return false
+		}
+	}
+})