ffi: don't allow size calculation of bitfield type.

* ffi.c (ffi_size): Check for a bitfield type and
diagnose.

1 files changed, 4 insertions, 0 deletions

diff --git a/ffi.c b/ffi.c
index 42a16db0..255a318d 100644
--- a/ffi.c
+++ b/ffi.c
@@ -3029,7 +3029,11 @@ val ffi_typedef(val name, val type)
 
 val ffi_size(val type)
 {
+  val self = lit("ffi-size");
   struct txr_ffi_type *tft = ffi_type_struct_checked(type);
+  if (tft->size == 0 && bitfield_syntax_p(tft->syntax))
+    uw_throwf(error_s, lit("~a: bitfield type ~s has no size"),
+              self, type, nao);
   return num(tft->size);
 }