From e9c4d48cf9289fe64f423edf87bfde6873aa0590 Mon Sep 17 00:00:00 2001
From: ProgramSnail <purpurebacterium@yandex.ru>
Date: Thu, 7 Nov 2024 00:56:21 +0300
Subject: [PATCH] closure fix

---
 byterun/include/stack.h   |  1 +
 byterun/src/interpreter.c |  7 ++++---
 byterun/src/stack.c       | 26 ++++++++++++++++++--------
 3 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/byterun/include/stack.h b/byterun/include/stack.h
index c63ef6e3c..e03e8badb 100644
--- a/byterun/include/stack.h
+++ b/byterun/include/stack.h
@@ -9,6 +9,7 @@
 
 void **s_top(struct State *s);
 bool s_is_empty(struct State *s);
+void **s_nth(struct State *s, aint n);
 void **s_peek(struct State *s);
 aint *s_peek_i(struct State *s);
 
diff --git a/byterun/src/interpreter.c b/byterun/src/interpreter.c
index c961aa3ec..039b62790 100644
--- a/byterun/src/interpreter.c
+++ b/byterun/src/interpreter.c
@@ -283,15 +283,16 @@ void run(bytefile *bf) {
         break;
       }
 
-      case 5: // CALLC %d // call clojure
-        ip_read_int(&s.ip); // args count
+      case 5: { // CALLC %d // call clojure
+        aint args_count = ip_read_int(&s.ip); // args count
 
         call_happened = true;
         s.is_closure_call = true;
         s.call_ip = s.ip;
 
-        s.ip = Belem(s.sp, BOX(0)); // use offset instead ??
+        s.ip = Belem(*s_nth(&s, args_count), BOX(0)); // use offset instead ??
         break;
+      }
 
       case 6: {                          // CALL 0x%.8x %d // call function
         int call_p = ip_read_int(&s.ip);
diff --git a/byterun/src/stack.c b/byterun/src/stack.c
index bf428ed91..19ca47e3b 100644
--- a/byterun/src/stack.c
+++ b/byterun/src/stack.c
@@ -45,6 +45,20 @@ bool s_is_empty(struct State* s) {
   return false;
 }
 
+void **s_nth(struct State *s, aint n) {
+  if (n < 0) {
+    failure("can't access stack by negative index");
+  }
+  if (s->sp + n >= s_top(s)) {
+    failure("not enough elements in stack");
+  }
+  if (s->fp != NULL && s->sp + n >= f_locals(s->fp)) {
+    failure("not enough elements in function stack");
+  }
+
+  return s->sp + n;
+}
+
 void** s_peek(struct State* s) {
   if (s->sp == s_top(s)) {
     failure("empty stack");
@@ -115,21 +129,17 @@ void s_enter_f(struct State *s, char *rp, bool is_closure_call, auint args_sz, a
   printf("-> %i locals sz\n", locals_sz);
 
   // check that params count is valid
-  if (s->sp + (aint)args_sz - 1 >= s_top(s)) {
+  if (s->sp + (aint)args_sz - (is_closure_call ? 0 : 1) >= s_top(s)) {
     failure("not enough parameters in stack");
   }
-  if (s->fp != NULL && s->sp + (aint)args_sz - 1 >= f_locals(s->fp)) {
+  if (s->fp != NULL && s->sp + (aint)args_sz - (is_closure_call ? 0 : 1) >= f_locals(s->fp)) {
     failure("not enough parameters in function stack");
   }
 
-  if (!is_closure_call) {
-    s_push_nil(s);
-  }
-
-  void* closure = s_peek(s);
+  void* closure = is_closure_call ? s_nth(s, args_sz) : NULL;
 
   // s_push_nil(s); // sp contains value, frame starts with next value
-  s_pushn_nil(s, frame_sz() - 1);
+  s_pushn_nil(s, frame_sz());
 
   // create frame
   struct Frame frame = {