simplify gc model

source/quickjs-internal.h

@@ -361,13 +361,7 @@ struct JSClass {
 #define JS_MODE_BACKTRACE_BARRIER \
   (1 << 3) /* stop backtrace before this frame */
 
-typedef struct JSFrameRegister {
-  objhdr_t hdr; // capacity in this is the total number of words of the object, including the 4 words of overhead and all slots
-  JSValue function; // JSFunction, function object being invoked
-  JSValue caller; // JSFrameRegister, the frame that called this one
-  JSValue address; // address of the instruction in the code that should be executed upon return
-  JSValue slots[]; // inline memory. order is [this][input args][closed over vars][non closed over vars][temporaries]
-} JSFrameRegister; /// extra note: when this frame returns, caller should be set to 0. If caller is found to be 0, then the GC can reduce this frame's slots down to [this][input_args][closed over vars]; if no closed over vars it can be totally removed; may happen naturally in GC since it would have no refs?
+/* JSFrameRegister is now an alias for JSFrame — see JSFrame definition below */
 
 /* ============================================================
    Register-Based VM Data Structures
@@ -823,17 +817,18 @@ typedef struct JSCodeRegister {
 } JSCodeRegister;
 
 
-/* Frame for closures - used by link-time relocation model where closures
-   reference outer frames via (depth, slot) addressing.
-   Stores function as JSValue to survive GC movements. */
+/* Unified frame struct — used by the register VM and closures.
+   All fields are JSValues so the GC can scan them uniformly. */
 typedef struct JSFrame {
   objhdr_t header;           /* OBJ_FRAME, cap56 = slot count */
-  JSValue function;          /* JSValue for GC safety (use JS_VALUE_GET_FUNCTION) */
-  JSValue caller;            /* JSValue for GC safety (unused currently) */
-  uint32_t return_pc;
+  JSValue function;          /* JSFunction, function object being invoked */
+  JSValue caller;            /* JSFrame, the frame that called this one */
+  JSValue address;           /* return PC stored as JS_NewInt32 */
   JSValue slots[];           /* [this][args][captured][locals][temps] */
 } JSFrame;
 
+typedef JSFrame JSFrameRegister;
+
 static inline objhdr_t objhdr_set_s (objhdr_t h, bool s) {
   return s ? (h | OBJHDR_S_MASK) : (h & ~OBJHDR_S_MASK);
 }
@@ -903,7 +898,8 @@ typedef struct JSArray {
   JSValue values[];               /* inline flexible array member */
 } JSArray;
 
-/* JSBlob - binary data per memory.md */
+/* JSBlob — not allocated on GC heap (blobs use JSRecord + opaque).
+   Struct kept for reference; gc_object_size/gc_scan_object do not handle OBJ_BLOB. */
 typedef struct JSBlob {
   objhdr_t mist_hdr;
   word_t length;
@@ -926,7 +922,7 @@ typedef slot JSRecordEntry;
 
 typedef struct JSRecord {
   objhdr_t mist_hdr;
-  struct JSRecord *proto;
+  JSValue proto;                  /* prototype as JSValue (JS_NULL if none) */
   word_t len;                     /* number of entries */
   slot slots[]; /* slots[0] reserved: key low32=class_id, key high32=rec_id, val=opaque */
 } JSRecord;
@@ -1071,6 +1067,13 @@ static JS_BOOL JSText_equal_ascii (const JSText *text, JSValue imm) {
    enough to call the interrupt callback often. */
 #define JS_INTERRUPT_COUNTER_INIT 10000
 
+/* Auto-rooted C call argv — GC updates values in-place */
+typedef struct CCallRoot {
+  JSValue *argv;          /* points to C-stack-local array */
+  int argc;
+  struct CCallRoot *prev; /* stack for nesting (C -> JS -> C -> ...) */
+} CCallRoot;
+
 struct JSContext {
   JSRuntime *rt;
 
@@ -1102,6 +1105,7 @@ struct JSContext {
 
   JSGCRef *top_gc_ref;  /* used to reference temporary GC roots (stack top) */
   JSGCRef *last_gc_ref; /* used to reference temporary GC roots (list) */
+  CCallRoot *c_call_root; /* stack of auto-rooted C call argv arrays */
 
   int class_count; /* size of class_array and class_proto */
   JSClass *class_array;
@@ -1234,7 +1238,7 @@ typedef struct JSRegExp {
 
 /* Get prototype from object (works for both JSRecord and JSRecord since they
  * share layout) */
-#define JS_OBJ_GET_PROTO(p) ((JSRecord *)((JSRecord *)(p))->proto)
+#define JS_OBJ_GET_PROTO(p) (JS_IsNull(((JSRecord *)(p))->proto) ? NULL : (JSRecord *)JS_VALUE_GET_PTR(((JSRecord *)(p))->proto))
 
 /* Initial capacity for new records (mask = 7, 8 slots total) */
 #define JS_RECORD_INITIAL_MASK 7