add pic_realloc

include/picrin.h

@@ -31,6 +31,7 @@ typedef struct {
 typedef pic_value (*pic_func_t)(pic_state *);
 
 void *pic_alloc(pic_state *, size_t);
+void *pic_realloc(pic_state *, void *, size_t);
 struct pic_object *pic_obj_alloc(pic_state *, size_t, enum pic_tt);
 void pic_free(pic_state *, void *);
 

src/gc.c

@@ -43,6 +43,16 @@ pic_alloc(pic_state *pic, size_t size)
   return ptr;
 }
 
+void *
+pic_realloc(pic_state *pic, void *ptr, size_t size)
+{
+  ptr = realloc(ptr, size);
+  if (ptr == NULL) {
+    pic_raise(pic, "memory exhausted");
+  }
+  return ptr;
+}
+
 void
 pic_free(pic_state *pic, void *ptr)
 {