From a06e6ac6ba68214171e995a7cc1ffe205a070d8b Mon Sep 17 00:00:00 2001
From: blueloveTH <blueloveth@foxmail.com>
Date: Mon, 27 Jul 2026 03:18:48 +0800
Subject: [PATCH] fix bugs

---
 src/compiler/lexer.c | 13 ++++--
 src/interpreter/vm.c | 97 ++++++++++++++++++++++++--------------------
 2 files changed, 63 insertions(+), 47 deletions(-)

diff --git a/src/compiler/lexer.c b/src/compiler/lexer.c
index 34a8343d..bab4c4de 100644
--- a/src/compiler/lexer.c
+++ b/src/compiler/lexer.c
@@ -189,8 +189,8 @@ static Error* LexerError(Lexer* self, const char* fmt, ...) {
     err->src = self->src;
     PK_INCREF(self->src);
     err->lineno = self->current_line;
-    const char* end = self->src->source->data + self->src->source->size;
-    if(self->curr_char <= end && *self->curr_char == '\n') { err->lineno--; }
+    const char* p_end = self->src->source->data + self->src->source->size;
+    if(self->curr_char <= p_end && *self->curr_char == '\n') { err->lineno--; }
     va_list args;
     va_start(args, fmt);
     vsnprintf(err->msg, sizeof(err->msg), fmt, args);
@@ -282,9 +282,16 @@ static Error* _eat_string(Lexer* self, c11_sbuf* buff, char quote, enum StringTy
                 case 'b': c11_sbuf__write_char(buff, '\b'); break;
                 case 'f': c11_sbuf__write_char(buff, '\f'); break;
                 case 'v': c11_sbuf__write_char(buff, '\v'); break;
-                // Special case for the often used \0 while we don't have full support for octal literals.
+                // Special case for the often used \0 while we don't have full support for octal
+                // literals.
                 case '0': c11_sbuf__write_char(buff, '\0'); break;
                 case 'x': {
+                    // check there are at least 2 chars can read
+                    const char* p_end = self->src->source->data + self->src->source->size;
+                    if(p_end - self->curr_char < 2) {
+                        return LexerError(self, "invalid hex escape");
+                    }
+
                     char hex[3] = {eatchar(self), eatchar(self), '\0'};
                     int code;
                     if(sscanf(hex, "%x", &code) != 1 || code > 0xFF) {
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 1db9ef6d..47578ded 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -713,53 +713,62 @@ void ManagedHeap__mark(ManagedHeap* self) {
             }
         }
 
-        void* ud = PyObject__userdata(obj);
-        switch(obj->type) {
-            case tp_list: {
-                List* self = ud;
-                for(int i = 0; i < self->length; i++) {
-                    py_TValue* val = c11__at(py_TValue, self, i);
-                    pk__mark_value(val);
+        if(obj->type > tp_object) {
+            // NOTE: `defaultdict` -> `dict` -> `object`
+            // NOTE: native types must extend from `object`.
+            py_TypeInfo* ti = pk_typeinfo(obj->type);
+            while(ti->base != tp_object) {
+                ti = ti->base_ti;
+            }
+
+            void* ud = PyObject__userdata(obj);
+            switch(ti->index) {
+                case tp_list: {
+                    List* self = ud;
+                    for(int i = 0; i < self->length; i++) {
+                        py_TValue* val = c11__at(py_TValue, self, i);
+                        pk__mark_value(val);
+                    }
+                    break;
                 }
-                break;
-            }
-            case tp_dict: {
-                Dict* self = ud;
-                for(int i = 0; i < self->entries.length; i++) {
-                    DictEntry* entry = c11__at(DictEntry, &self->entries, i);
-                    if(py_isnil(&entry->key)) continue;
-                    pk__mark_value(&entry->key);
-                    pk__mark_value(&entry->val);
+                case tp_dict: {
+                    Dict* self = ud;
+                    for(int i = 0; i < self->entries.length; i++) {
+                        DictEntry* entry = c11__at(DictEntry, &self->entries, i);
+                        if(py_isnil(&entry->key)) continue;
+                        pk__mark_value(&entry->key);
+                        pk__mark_value(&entry->val);
+                    }
+                    break;
                 }
-                break;
-            }
-            case tp_generator: {
-                Generator* self = ud;
-                if(self->frame) Frame__gc_mark(self->frame, p_stack);
-                break;
-            }
-            case tp_function: {
-                function__gc_mark(ud, p_stack);
-                break;
-            }
-            case tp_BaseException: {
-                BaseException* self = ud;
-                pk__mark_value(&self->args);
-                pk__mark_value(&self->inner_exc);
-                c11__foreach(BaseExceptionFrame, &self->stacktrace, frame) {
-                    pk__mark_value(&frame->locals);
-                    pk__mark_value(&frame->globals);
+                case tp_generator: {
+                    Generator* self = ud;
+                    if(self->frame) Frame__gc_mark(self->frame, p_stack);
+                    break;
+                }
+                case tp_function: {
+                    function__gc_mark(ud, p_stack);
+                    break;
+                }
+                case tp_BaseException: {
+                    BaseException* self = ud;
+                    pk__mark_value(&self->args);
+                    pk__mark_value(&self->inner_exc);
+                    c11__foreach(BaseExceptionFrame, &self->stacktrace, frame) {
+                        pk__mark_value(&frame->locals);
+                        pk__mark_value(&frame->globals);
+                    }
+                    break;
+                }
+                case tp_code: {
+                    CodeObject* self = ud;
+                    CodeObject__gc_mark(self, p_stack);
+                    break;
+                }
+                case tp_chunked_array2d: {
+                    c11_chunked_array2d__mark(ud, p_stack);
+                    break;
                 }
-                break;
-            }
-            case tp_code: {
-                CodeObject* self = ud;
-                CodeObject__gc_mark(self, p_stack);
-                break;
-            }
-            case tp_chunked_array2d: {
-                c11_chunked_array2d__mark(ud, p_stack);
-                break;
             }
         }
     }