Feature: Add support for stripping XML comments and declarations

src/xml.c

@@ -826,6 +826,70 @@ node_creation:;
  */
 struct xml_document* xml_parse_document(uint8_t* buffer, size_t length) {
 
+    /* 
+     * Pre-processing: Remove XML comments and declarations.
+     * 
+     * This loop iterates through the buffer and strips out any content between
+     * `<!--` and `-->` (comments) or `<?` and `?>` (declarations).
+     * The modification is performed in-place by shifting valid bytes.
+     * 
+     * @warning This is a naive implementation. It does not check if the comment
+     * markers are inside strings or attributes. Patterns like <node attr="<!--" />
+     * will be incorrectly parsed as the start of a comment.
+     */
+    uint32_t document_length = 0;
+    uint32_t buffer_index = 0;
+
+    uint8_t declare_flag = 0;
+    uint8_t comment_flag = 0;
+
+    while (buffer_index < length)
+    {
+        if (declare_flag == 0 && comment_flag == 0)
+        {
+            memcpy(&buffer[document_length], &buffer[buffer_index], 1);
+            document_length++;
+        }
+
+        if (buffer_index >= 1)
+        {
+            if (!strncmp(&buffer[buffer_index - 1], "<?", 2))
+            {
+                declare_flag = 1;
+                if (comment_flag == 0)
+                {
+                    document_length -= 2;
+                }
+
+            }
+
+            if (!strncmp(&buffer[buffer_index - 1], "?>", 2))
+            {
+                declare_flag = 0;
+            }
+        }
+        if (buffer_index >= 3)
+        {
+            if (!strncmp(&buffer[buffer_index - 3], "<!--", 4))
+            {
+                comment_flag = 1;
+                if (declare_flag == 0)
+                {
+                    document_length -= 4;
+                }
+            }
+
+            if (!strncmp(&buffer[buffer_index - 2], "-->", 3))
+            {
+                comment_flag = 0;
+            }
+        }
+
+        buffer_index++;
+    }
+
+    length = document_length;
+
 	/* Initialize parser
 	 */
 	struct xml_parser parser = {