ffi: correct tft->nmemb under zero-bit fields.

* ffi.c (make_ffi_type_struct, make_ffi_type_union): Assign
tft->memb = memb after the loop which compiles the member
types, because memb is decremented in the case of the
zero-width bitfield. This hasn't cause an issue because the
extra members are all zero, so their slot symbol is nil, and
all the relevant operations skip a nil named member.

1 files changed, 4 insertions, 2 deletions

diff --git a/ffi.c b/ffi.c
index a0f58e9b..dd2fe20d 100644
--- a/ffi.c
+++ b/ffi.c
@@ -3260,7 +3260,6 @@ static val make_ffi_type_struct(val syntax, val lisp_type,
   tft->alloc = ffi_fixed_alloc;
   tft->dynsize = ffi_fixed_dynsize;
   tft->free = free;
-  tft->memb = memb;
 
   tft->incomplete = 1;
 
@@ -3351,6 +3350,8 @@ static val make_ffi_type_struct(val syntax, val lisp_type,
       tft->by_value_in = 1;
   }
 
+  tft->memb = memb;
+
   if (bit_offs > 0) {
     bug_unless (bit_offs < 8);
     offs++;
@@ -3429,7 +3430,6 @@ static val make_ffi_type_union(val syntax, val use_existing, val self)
   tft->alloc = ffi_fixed_alloc;
   tft->dynsize = ffi_fixed_dynsize;
   tft->free = free;
-  tft->memb = memb;
 
   tft->incomplete = 1;
 
@@ -3477,6 +3477,8 @@ static val make_ffi_type_union(val syntax, val use_existing, val self)
     }
   }
 
+  tft->memb = memb;
+
   if (flexp)
     uw_throwf(error_s,
               lit("~a: unions cannot contain incomplete member"),