Enable Max Depth for Tokenizer to Avoid Crash

Sources/Splash/Output/AttributedStringOutputFormat.swift

@@ -34,17 +34,26 @@ public extension AttributedStringOutputFormat {
         }
 
         public mutating func addToken(_ token: String, ofType type: TokenType) {
-            let color = theme.tokenColors[type] ?? Color(red: 1, green: 1, blue: 1)
-            string.append(token, font: font, color: color)
+            if #available(iOS 13.0, macCatalyst 13.0, *) {
+                let color = theme.tokenColors[type] ?? Color.label
+                string.append(token, font: font, color: color)
+            } else {
+                string.append(token, font: font, color: Color(red: 1, green: 1, blue: 1))
+            }
         }
 
         public mutating func addPlainText(_ text: String) {
             string.append(text, font: font, color: theme.plainTextColor)
         }
 
         public mutating func addWhitespace(_ whitespace: String) {
-            let color = Color(red: 1, green: 1, blue: 1)
-            string.append(whitespace, font: font, color: color)
+            if #available(iOS 13.0, macCatalyst 13.0, *) {
+                let color = Color.label
+                string.append(whitespace, font: font, color: color)
+            } else {
+                let color = Color(red: 1, green: 1, blue: 1)
+                string.append(whitespace, font: font, color: color)
+            }
         }
 
         public func build() -> NSAttributedString {

Sources/Splash/Tokenizing/Tokenizer.swift

@@ -25,8 +25,8 @@ private extension Tokenizer {
         }
 
         mutating func next() -> Segment? {
-            var segment = nextSegment ?? iterator.next()
-            nextSegment = iterator.next()
+            var segment = nextSegment ?? iterator.controlledIterate(depth: 32)
+            nextSegment = iterator.controlledIterate(depth: 32)
             segment?.tokens.next = nextSegment?.tokens.current
             return segment
         }
@@ -60,6 +60,12 @@ private extension Tokenizer {
         }
 
         mutating func next() -> Segment? {
+            controlledIterate(depth: 32)
+        }
+
+        mutating func controlledIterate(depth: Int) -> Segment? {
+            guard depth >= 0 else { return nil }
+
             let nextIndex = makeNextIndex()
 
             guard nextIndex != code.endIndex else {
@@ -75,11 +81,12 @@ private extension Tokenizer {
             case .token, .delimiter:
                 guard var segment = segments.current else {
                     segments.current = makeSegment(with: component, at: nextIndex)
-                    return next()
+                    return controlledIterate(depth: depth - 1)
                 }
 
                 guard segment.trailingWhitespace == nil,
-                      component.isDelimiter == segment.currentTokenIsDelimiter else {
+                      component.isDelimiter == segment.currentTokenIsDelimiter
+                else {
                     return finish(segment, with: component, at: nextIndex)
                 }
 
@@ -95,14 +102,14 @@ private extension Tokenizer {
 
                 segment.tokens.current.append(component.character)
                 segments.current = segment
-                return next()
+                return controlledIterate(depth: depth - 1)
             case .whitespace, .newline:
                 guard var segment = segments.current else {
                     var segment = makeSegment(with: component, at: nextIndex)
                     segment.trailingWhitespace = component.token
                     segment.isLastOnLine = component.isNewline
                     segments.current = segment
-                    return next()
+                    return controlledIterate(depth: depth - 1)
                 }
 
                 if var existingWhitespace = segment.trailingWhitespace {
@@ -117,7 +124,7 @@ private extension Tokenizer {
                 }
 
                 segments.current = segment
-                return next()
+                return controlledIterate(depth: depth - 1)
             }
         }
 

Tests/SplashTests/Tests/StackOverflowTests.swift

@@ -0,0 +1,20 @@
+//
+//  StackOverflowTests.swift
+//  Splash
+//
+//  Created by 秋星桥 on 3/15/25.
+//
+
+import Foundation
+import Splash
+import XCTest
+
+final class StackOverflowTests: SyntaxHighlighterTestCase {
+    func testStackOverflow() {
+        _ = highlighter.highlight(testDocument)
+    }
+}
+
+private let testDocument = """
+U1LDE3LjU1LDAsMSwwLTM1LjwwLDEPHBhdGggY2xhc3M9ImNscy0xIiBkPSJNMjMzLjQ1LDQwLjgxYTE3LjtMzUuMSwwVjMzMGExMS42MywxMS42MywwLDEsMC0yMy4yNiwwdjQwLjg2YTQwLjgxLDQwLjgxLDAsMCwwLDgxLjYyNTUsMTcuNTUsMCwwLDEtMzUuMSwwVjMzMGExMS42MywxMS42MywwLDEsMC0yMy4yNiwwdjQwLjg2YTQwLjgxLDQwLjgxLDAsMCwwLDgxLjYyLDBWNDAuODFjE1LjksNjMuNEE0MC44Niw0MC44NiwwLDAsMCw0aIi8hdGggY2xhc3M9ImNscy0xIiBkPSJNMjMzLjQ1LDQwLjgxYTE3LjU1LDE3LjU1LDAsMSwwLTM1LjEsMFYzMzEuNTZhNDAuODIsNDAuODIsMCwwLDEtODEuNjMsMFYxNDVhMTcuNTUsMTcu40MmExMS42MywxMS42MywwLDAsMSwyMy4yNiwwdjI4LjY2YTE3LjU1LDE3LjU1LDAsMCwwLDM1LjEsMFYxNDVBNDAuODIsNDAuODIsMCwwLDEsMTQwLDE0NVYzMzEuNTZhMTsMFYyODEuNTZhMTEuNjMsMTEuNjMsMCwxLDEtMjMuMjYsMFptMjE1LjksNjMuNEE0MC44Niw0MC44NiwwLDAsMCw0MDguNTMsMTQ1VjMwMC44NWExNy41NSwxNy41NSwwLDAsMS0zNS4wMDguNTMsMTQ1VjMwMC44NWExNy41NSwxNy41NSwwLDAsMS0zNS4wOSwwdi0yNjBhNDAuODIsNDAuODIsMCwwLDAtODEuNjMsMFYzNzAuODlhMTcuLjg1LDQwMCwxLDAtMzUuMDksMHY3ExLjYzLDExLjYzLDAsMCwwLDIzLjI2LDBWMTQ1QTQwLjg1LDQwLjg1LDAsMCwwLDQ0OS4zNSwxMDQuMjFaIi8NmE0MC44Miw0MC44MiwwLDAsMS04MS42MywwVjMFYxNDVBNDAuODIsNDAuODIsMCwwLDEsMTQwLDE0NVYzMzEuNTZhMTcuNTUsMTcuNTUsMCwwLDAsMzUuMSwwVjIxNy41aDBWNDAuODFhNDAuODEsNDAuODEsMCwxLDEsODEuNjAsMhMTcuNTUsMTcuNTUsMCwwLNTUsQTQwLDBWNDAuODFhMTcuNTUsMTcuNTUsMCwwLDEsMzUuMSwwdjI2MGE0MC44Miw0MC44MiwwLDAsMCw4MS42MywwVjE0NWExNy41NSwxNy41NSwwLDEsMSwzNS4xLDBWMjgxLjU2YTQuMjFOSwwdi0yNjBhNDAuODIsNDAEsMFYzMzEuNTZhNDAuODIsNDAuODIsMCwwLDEtODEuNjMsMFYxNDVhMTcuNTUsMTcuNTUsMCwxLDAtMzUuMDksMHY3OS4wPHBuODIsMCE5NSDEsMzUuMSwwdjI2MGE0MC44Miw0MC44MiwwLDAsMCw4MS42MywwVjE0NWExNy41NSwxNy41NSwwLDEsMSwzNS4xLDBWMjgxLjU2YTExLjYzLDExLjYzLDAsMCwwLDIzLjI2LDBWMTQ1Ljg1LDcuNTUsMTcuNTUsMCwwLDAsMzUuMSwwVjIxNy41aDBWNDAuODFhNDAuODEsNDAuODEsMCwxLDEsODEuNjIsMFYyODEuNTZhMTEuNjMsMTEuNjMsMCwxLDEtMjMuMjYsMFptMCwwLDQ0OS4zNSwxMDOS4wNmE0MC44Miw0MC44MiwwLDAsMS04MS42MywwVjE5NS40MmExMS42MywxMS42MywwLDAsMSwyMy4yNiwwdjI4LjY2YTE3LjU1LDE3LjU1LDAsMCwwLDM1LjEswwLDAtODEuNjMsMFYzNzAuODlhMTcuNTUsMTcuNTUsMC
+"""