Small changes

Makefile

@@ -1,7 +1,11 @@
-CC=clang
+CC ?= clang
+CFLAGS ?=
 
 all:
-	$(CC) -o lbr -O2 -Wall -Wextra -Wpedantic src/*.c
+	$(CC) -o lbr -O2 -Wall -Wextra -Wpedantic $(CFLAGS) src/*.c
+
+clean:
+	rm lbr
 
 test:
 	./lbr tests/test.lb

src/execute.c

@@ -532,11 +532,7 @@ void execute(Stack *stack, Stack *originstack, char *modname)
 
         if (!strcmp(NAME, "size"))
         {
-            int i = 0;
-            while (i < stack->pointer)
-                i++;
-
-            stack_push(stack, i);
+            stack_push(stack, stack->pointer);
             continue;
         }