only allocate as much space on stack for return pointer as needed

hoodmane · Jun 26, 2021 · e54a30f · e54a30f
1 parent af8ce52
commit e54a30f
Showing 1 changed file with 13 additions and 2 deletions.
diff --git a/src/wasm32/ffi.c b/src/wasm32/ffi.c
@@ -481,8 +481,19 @@ ffi_prep_closure_loc_helper,
  if (ret_by_arg) {
  ret_ptr = args[0];
  } else {
- cur_ptr -= 8;
- cur_ptr &= (~(8 - 1));
+ var ret_size;
+ switch (sig[ret_by_arg]) {
+ case "i":
+ case "f":
+ ret_size = 4;
+ break;
+ case "j":
+ case "d":
+ ret_size = 8;
+ break;
+ }
+ cur_ptr -= ret_size;
+ cur_ptr &= (~(ret_size - 1));
  ret_ptr = cur_ptr;
  }
  cur_ptr -= 4 * (sig.length - 1 - ret_by_arg);