From 6a534ba6352ad5e19c3e74a5f2e9e2590bd98062 Mon Sep 17 00:00:00 2001
From: Pasha Bibko <156938226+PashaBibko@users.noreply.github.com>
Date: Wed, 23 Jul 2025 18:22:24 +0100
Subject: [PATCH] Stopped memory leak with transferring tokens

---
 Lexer/inc/Token.h   | 10 ++++++++++
 Lexer/src/Token.cpp | 30 ++++++++++++++++++++++++++----
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/Lexer/inc/Token.h b/Lexer/inc/Token.h
index b354322..bfc0892 100644
--- a/Lexer/inc/Token.h
+++ b/Lexer/inc/Token.h
@@ -92,6 +92,16 @@ namespace LXC::Lexer
             // Constructor to set the data of the token for more complex token types //
             Token(const LexerContext& ctx, uint32_t start, unsigned short len, TokenType _type);
 
+            // Copy constructor //
+            Token(const Token& other);
+
+            // Move constructor (transfers memory allocated) //
+            Token(Token&& other) noexcept;
+
+            // Cannot use these as members are const //
+            Token& operator=(const Token&) = delete;
+            Token& operator=(Token&&) = delete;
+
             // Deconstructor to clean up the allocated memory //
             ~Token();
 
diff --git a/Lexer/src/Token.cpp b/Lexer/src/Token.cpp
index c1a5a39..c1b4dbc 100644
--- a/Lexer/src/Token.cpp
+++ b/Lexer/src/Token.cpp
@@ -21,14 +21,35 @@ namespace LXC::Lexer
         }
     }
 
+    // Copy constructor //
+    Token::Token(const Token& other) :
+        type(other.type), length(other.length), index(other.index), contents(nullptr)
+    {
+        if (other.contents != nullptr)
+        {
+            size_t len = std::strlen(other.contents) + 1; // Adds one for null-terminator
+            contents = new char[len];
+            std::memcpy(contents, other.contents, len);
+        }
+    }
+
+    // Move constructor (transfers memory allocated) //
+    Token::Token(Token&& other) noexcept :
+        type(other.type), length(other.length), index(other.index), contents(other.contents)
+    {
+        // Stops the other from thinking it owns the memory //
+        other.contents = nullptr;
+    }
+
     // Destructor to clean up the memory of the token that can be allocated //
     Token::~Token()
     {
         // Frees any allocated memory //
-        //if (contents != nullptr)
-        //	delete[] contents;
-
-        contents = nullptr;
+        if (contents != nullptr) _UNLIKELY
+        {
+            delete[] contents;
+            contents = nullptr;
+        }
     }
 
     // Helper macro for converting type to string //
@@ -82,6 +103,7 @@ namespace LXC::Lexer
         std::ostringstream os;
         os << std::setw(25) << std::left << TokenTypeToCStr(type) << " | ";
 
+        // Prints the contents if they are not null //
         if (contents != nullptr)
             os << std::setw(25) << std::left << std::string('"' + std::string(contents) + '"');
         else