From 05b57550dad6f7f4bb37ddbdca30e4fb94bc8006 Mon Sep 17 00:00:00 2001
From: John Alanbrook <john@pockle.world>
Date: Mon, 29 Dec 2025 13:01:05 -0600
Subject: [PATCH] vm trampoline setup

---
 source/quickjs.c | 59 +++++++++++++++++++++++++++++++++++++++++++++---
 tests/suite.cm   |  2 +-
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/source/quickjs.c b/source/quickjs.c
index 86840cac..2a9d20c7 100644
--- a/source/quickjs.c
+++ b/source/quickjs.c
@@ -337,6 +337,28 @@ struct VMFrame {
     int stack_size_allocated;  /* total size allocated for this frame */
 };
 
+/* Execution state returned by vm_execute_frame */
+typedef enum {
+  VM_EXEC_NORMAL,      /* Continue executing current frame */
+  VM_EXEC_RETURN,      /* Frame returned, pop and resume caller */
+  VM_EXEC_CALL,        /* Need to push new frame for call */
+  VM_EXEC_EXCEPTION,   /* Exception thrown, unwind frames */
+} VMExecState;
+
+/* Call info for frame push */
+typedef struct {
+  JSValue func_obj;
+  JSValue this_obj;
+  JSValue new_target;
+  int argc;
+  JSValue *argv;
+  const uint8_t *ret_pc;
+  int ret_sp_offset;
+  int call_argc;
+  int call_has_this;
+  int is_tail_call;
+} VMCallInfo;
+
 typedef enum {
     JS_GC_OBJ_TYPE_JS_OBJECT,
     JS_GC_OBJ_TYPE_FUNCTION_BYTECODE,
@@ -902,6 +924,9 @@ static JSValue js_call_bound_function(JSContext *ctx, JSValueConst func_obj,
 static JSValue JS_CallInternal(JSContext *ctx, JSValueConst func_obj,
                                JSValueConst this_obj, JSValueConst new_target,
                                int argc, JSValue *argv, int flags);
+static JSValue JS_CallInternal_OLD(JSContext *ctx, JSValueConst func_obj,
+                               JSValueConst this_obj, JSValueConst new_target,
+                               int argc, JSValue *argv, int flags);
 static JSValue JS_CallConstructorInternal(JSContext *ctx,
                                           JSValueConst func_obj,
                                           JSValueConst new_target,
@@ -12968,9 +12993,35 @@ static JSValue JS_CallTrampoline(JSContext *caller_ctx, JSValueConst func_obj,
     return ret_val;
 }
 
+/* Execute a single frame (delegates to OLD implementation for now) */
+static VMExecState vm_execute_frame(JSContext *ctx, struct VMFrame *frame,
+                                    JSValue *ret_val, VMCallInfo *call_info)
+{
+  /* TODO: Replace with proper bytecode loop extraction */
+  /* For now, delegate to the old recursive implementation */
+  *ret_val = JS_CallInternal_OLD(ctx, frame->cur_func, frame->this_obj,
+                                  frame->new_target, frame->arg_count,
+                                  vm_frame_get_arg_buf(ctx, frame), 0);
+  if (JS_IsException(*ret_val))
+    return VM_EXEC_EXCEPTION;
+  return VM_EXEC_RETURN;
+}
+
+/* Trampoline-based JS_CallInternal - eliminates C stack recursion */
 static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
                                JSValueConst this_obj, JSValueConst new_target,
                                int argc, JSValue *argv, int flags)
+{
+  /* TODO: Implement full trampoline */
+  /* For now, just delegate to OLD implementation */
+  return JS_CallInternal_OLD(caller_ctx, func_obj, this_obj, new_target,
+                             argc, argv, flags);
+}
+
+/* OLD recursive implementation - to be removed after trampoline is complete */
+static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
+                               JSValueConst this_obj, JSValueConst new_target,
+                               int argc, JSValue *argv, int flags)
 {
     JSRuntime *rt = caller_ctx->rt;
     JSContext *ctx;
@@ -13370,7 +13421,8 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
                 /* Record call site */
                 profile_record_call_site(rt, b, (uint32_t)(pc - b->byte_code_buf));
 #endif
-                ret_val = JS_CallInternal(ctx, call_argv[-1], JS_NULL,
+                /* TODO: Use trampoline - for now keep recursive */
+                ret_val = JS_CallInternal_OLD(ctx, call_argv[-1], JS_NULL,
                                           JS_NULL, call_argc, call_argv, 0);
                 if (unlikely(JS_IsException(ret_val)))
                     goto exception;
@@ -13414,7 +13466,7 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
                 /* Record call site */
                 profile_record_call_site(rt, b, (uint32_t)(pc - b->byte_code_buf));
 #endif
-                ret_val = JS_CallInternal(ctx, call_argv[-1], call_argv[-2],
+                ret_val = JS_CallInternal_OLD(ctx, call_argv[-1], call_argv[-2],
                                           JS_NULL, call_argc, call_argv, 0);
                 if (unlikely(JS_IsException(ret_val)))
                     goto exception;
@@ -13522,7 +13574,7 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
                     ret_val = JS_EvalObject(ctx, JS_NULL, obj,
                                             JS_EVAL_TYPE_DIRECT, scope_idx);
                 } else {
-                    ret_val = JS_CallInternal(ctx, call_argv[-1], JS_NULL,
+                    ret_val = JS_CallInternal_OLD(ctx, call_argv[-1], JS_NULL,
                                               JS_NULL, call_argc, call_argv, 0);
                 }
                 if (unlikely(JS_IsException(ret_val)))
@@ -15653,6 +15705,7 @@ enum {
     /* FutureReservedWords when parsing strict mode code */
     TOK_IMPLEMENTS,
     TOK_INTERFACE,
+    TOK_LET,
     TOK_PRIVATE,
     TOK_PROTECTED,
     TOK_PUBLIC,
diff --git a/tests/suite.cm b/tests/suite.cm
index 7cb91e49..a4b2e6d3 100644
--- a/tests/suite.cm
+++ b/tests/suite.cm
@@ -1,7 +1,7 @@
 // Comprehensive test suite for cell runtime stability
 // Tests all core features before implementing performance optimizations
 // (bytecode passes, ICs, quickening, tail call optimization)
-
+//
 return {
     // ============================================================================
     // ARITHMETIC OPERATORS - Numbers